The recent *sync enabling discovered that we are inserting into the
block_device pagecache counter to the expectations of the dirty data
tracking for dax mappings. This can lead to data corruption.
We want to support DAX for block devices eventually, but it requires
wider changes to properly manage the pagecache.
dump_stack+0x85/0xc2
dax_writeback_mapping_range+0x60/0xe0
blkdev_writepages+0x3f/0x50
do_writepages+0x21/0x30
__filemap_fdatawrite_range+0xc6/0x100
filemap_write_and_wait+0x4a/0xa0
set_blocksize+0x70/0xd0
sb_set_blocksize+0x1d/0x50
ext4_fill_super+0x75b/0x3360
mount_bdev+0x180/0x1b0
ext4_mount+0x15/0x20
mount_fs+0x38/0x170
Mark the support broken so its disabled by default, but otherwise still
available for testing.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@fb.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Request-based DM's blk-mq support (dm-mq) was reported to be 50% slower
than if an underlying null_blk device were used directly. One of the
reasons for this drop in performance is that blk_insert_clone_request()
was calling blk_mq_insert_request() with @async=true. This forced the
use of kblockd_schedule_delayed_work_on() to run the blk-mq hw queues
which ushered in ping-ponging between process context (fio in this case)
and kblockd's kworker to submit the cloned request. The ftrace
function_graph tracer showed:
kworker-2013 => fio-12190
fio-12190 => kworker-2013
...
kworker-2013 => fio-12190
fio-12190 => kworker-2013
...
Fixing blk_insert_clone_request()'s blk_mq_insert_request() call to
_not_ use kblockd to submit the cloned requests isn't enough to
eliminate the observed context switches.
In addition to this dm-mq specific blk-core fix, there are 2 DM core
fixes to dm-mq that (when paired with the blk-core fix) completely
eliminate the observed context switching:
1) don't blk_mq_run_hw_queues in blk-mq request completion
Motivated by desire to reduce overhead of dm-mq, punting to kblockd
just increases context switches.
In my testing against a really fast null_blk device there was no benefit
to running blk_mq_run_hw_queues() on completion (and no other blk-mq
driver does this). So hopefully this change doesn't induce the need for
yet another revert like commit 621739b00e !
2) use blk_mq_complete_request() in dm_complete_request()
blk_complete_request() doesn't offer the traditional q->mq_ops vs
.request_fn branching pattern that other historic block interfaces
do (e.g. blk_get_request). Using blk_mq_complete_request() for
blk-mq requests is important for performance. It should be noted
that, like blk_complete_request(), blk_mq_complete_request() doesn't
natively handle partial completions -- but the request-based
DM-multipath target does provide the required partial completion
support by dm.c:end_clone_bio() triggering requeueing of the request
via dm-mpath.c:multipath_end_io()'s return of DM_ENDIO_REQUEUE.
dm-mq fix#2 is _much_ more important than #1 for eliminating the
context switches.
Before: cpu : usr=15.10%, sys=59.39%, ctx=7905181, majf=0, minf=475
After: cpu : usr=20.60%, sys=79.35%, ctx=2008, majf=0, minf=472
With these changes multithreaded async read IOPs improved from ~950K
to ~1350K for this dm-mq stacked on null_blk test-case. The raw read
IOPs of the underlying null_blk device for the same workload is ~1950K.
Fixes: 7fb4898e0 ("block: add blk-mq support to blk_insert_cloned_request()")
Fixes: bfebd1cdb ("dm: add full blk-mq support to request-based DM")
Cc: stable@vger.kernel.org # 4.1+
Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
If block device is left runtime suspended during system suspend, resume
hook of the driver typically corrects runtime PM status of the device back
to "active" after it is resumed. However, this is not enough as queue's
runtime PM status is still "suspended". As long as it is in this state
blk_pm_peek_request() returns NULL and thus prevents new requests to be
processed.
Add new function blk_set_runtime_active() that can be used to force the
queue status back to "active" as needed.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull block fixes from Jens Axboe:
"A collection of fixes from the past few weeks that should go into 4.5.
This contains:
- Overflow fix for sysfs discard show function from Alan.
- A stacking limit init fix for max_dev_sectors, so we don't end up
artificially capping some use cases. From Keith.
- Have blk-mq proper end unstarted requests on a dying queue, instead
of pushing that to the driver. From Keith.
- NVMe:
- Update to Kconfig description for NVME_SCSI, since it was
vague and having it on is important for some SUSE distros.
From Christoph.
- Set of fixes from Keith, around surprise removal. Also kills
the no-merge flag, so it supports merging.
- Set of fixes for lightnvm from Matias, Javier, and Wenwei.
- Fix null_blk oops when asked for lightnvm, but not available. From
Matias.
- Copy-to-user EINTR fix from Hannes, fixing a case where SG_IO fails
if interrupted by a signal.
- Two floppy fixes from Jiri, fixing signal handling and blocking
open.
- A use-after-free fix for O_DIRECT, from Mike Krinkin.
- A block module ref count fix from Roman Pen.
- An fs IO wait accounting fix for O_DSYNC from Stephane Gasparini.
- Smaller reallo fix for xen-blkfront from Bob Liu.
- Removal of an unused struct member in the deadline IO scheduler,
from Tahsin.
- Also from Tahsin, properly initialize inode struct members
associated with cgroup writeback, if enabled.
- From Tejun, ensure that we keep the superblock pinned during cgroup
writeback"
* 'for-linus' of git://git.kernel.dk/linux-block: (25 commits)
blk: fix overflow in queue_discard_max_hw_show
writeback: initialize inode members that track writeback history
writeback: keep superblock pinned during cgroup writeback association switches
bio: return EINTR if copying to user space got interrupted
NVMe: Rate limit nvme IO warnings
NVMe: Poll device while still active during remove
NVMe: Requeue requests on suspended queues
NVMe: Allow request merges
NVMe: Fix io incapable return values
blk-mq: End unstarted requests on dying queue
block: Initialize max_dev_sectors to 0
null_blk: oops when initializing without lightnvm
block: fix module reference leak on put_disk() call for cgroups throttle
nvme: fix Kconfig description for BLK_DEV_NVME_SCSI
kernel/fs: fix I/O wait not accounted for RW O_DSYNC
floppy: refactor open() flags handling
lightnvm: allow to force mm initialization
lightnvm: check overflow and correct mlc pairs
lightnvm: fix request intersection locking in rrpc
lightnvm: warn if irqs are disabled in lock laddr
...
We get this right for queue_discard_max_show but not max_hw_show. Follow the
same pattern as queue_discard_max_show instead so that we don't truncate.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently q->mq_ops is used widely to decide if the queue
is mq or not, so we should set the 'flag' asap so that both
block core and drivers can get the correct mq info.
For example, commit 868f2f0b720(blk-mq: dynamic h/w context count)
moves the hctx's initialization before setting q->mq_ops in
blk_mq_init_allocated_queue(), then cause blk_alloc_flush_queue()
to think the queue is non-mq and don't allocate command size
for the per-hctx flush rq.
This patches should fix the problem reported by Sasha.
Cc: Keith Busch <keith.busch@intel.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Fixes: 868f2f0b72 ("blk-mq: dynamic h/w context count")
Signed-off-by: Jens Axboe <axboe@fb.com>
A set of seven fixes. Two regressions in the new hisi_sas arm driver, a
blacklist entry for the marvell console which was causing a reset cascade
without it, a race fix in the WRITE_SAME/DISCARD routines, a retry fix for the
rdac driver, without which, it would prematurely return EIO and a couple of
fixes for the hyper-v storvsc driver.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"A set of seven fixes:
Two regressions in the new hisi_sas arm driver, a blacklist entry for
the marvell console which was causing a reset cascade without it, a
race fix in the WRITE_SAME/DISCARD routines, a retry fix for the rdac
driver, without which, it would prematurely return EIO and a couple of
fixes for the hyper-v storvsc driver"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
block/sd: Return -EREMOTEIO when WRITE SAME and DISCARD are disabled
SCSI: Add Marvell Console to VPD blacklist
scsi_dh_rdac: always retry MODE SELECT on command lock violation
storvsc: Use the specified target ID in device lookup
storvsc: Install the storvsc specific timeout handler for FC devices
hisi_sas: fix v1 hw check for slot error
hisi_sas: add dependency for HAS_IOMEM
Commit 35dc248383 introduced a check for
current->mm to see if we have a user space context and only copies data
if we do. Now if an IO gets interrupted by a signal data isn't copied
into user space any more (as we don't have a user space context) but
user space isn't notified about it.
This patch modifies the behaviour to return -EINTR from bio_uncopy_user()
to notify userland that a signal has interrupted the syscall, otherwise
it could lead to a situation where the caller may get a buffer with
no data returned.
This can be reproduced by issuing SG_IO ioctl()s in one thread while
constantly sending signals to it.
Fixes: 35dc248 [SCSI] sg: Fix user memory corruption when SG_IO is interrupted by a signal
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org # v.3.11+
Signed-off-by: Jens Axboe <axboe@fb.com>
Go directly to ending a request if it wasn't started. Previously, completing a
request may invoke a driver callback for a request it didn't initialize.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The new queue limit is not used by the majority of block drivers, and
should be initialized to 0 for the driver's requested settings to be used.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The new queue limit is not used by the majority of block drivers, and
should be initialized to 0 for the driver's requested settings to be used.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The hardware's provided queue count may change at runtime with resource
provisioning. This patch allows a block driver to alter the number of
h/w queues available when its resource count changes.
The main part is a new blk-mq API to request a new number of h/w queues
for a given live tag set. The new API freezes all queues using that set,
then adjusts the allocated count prior to remapping these to CPUs.
The bulk of the rest just shifts where h/w contexts and all their
artifacts are allocated and freed.
The number of max h/w contexts is capped to the number of possible cpus
since there is no use for more than that. As such, all pre-allocated
memory for pointers need to account for the max possible rather than
the initial number of queues.
A side effect of this is that the blk-mq will proceed successfully as
long as it can allocate at least one h/w context. Previously it would
fail request queue initialization if less than the requested number
was allocated.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
get_disk(),get_gendisk() calls have non explicit side effect: they
increase the reference on the disk owner module.
The following is the correct sequence how to get a disk reference and
to put it:
disk = get_gendisk(...);
/* use disk */
owner = disk->fops->owner;
put_disk(disk);
module_put(owner);
fs/block_dev.c is aware of this required module_put() call, but f.e.
blkg_conf_finish(), which is located in block/blk-cgroup.c, does not put
a module reference. To see a leakage in action cgroups throttle config
can be used. In the following script I'm removing throttle for /dev/ram0
(actually this is NOP, because throttle was never set for this device):
# lsmod | grep brd
brd 5175 0
# i=100; while [ $i -gt 0 ]; do echo "1:0 0" > \
/sys/fs/cgroup/blkio/blkio.throttle.read_bps_device; i=$(($i - 1)); \
done
# lsmod | grep brd
brd 5175 100
Now brd module has 100 references.
The issue is fixed by calling module_put() just right away put_disk().
Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com>
Cc: Gi-Oh Kim <gi-oh.kim@profitbricks.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
When a process is doing Random Write with O_DSYNC flag
the I/O wait are not accounted in the kernel (get_cpu_iowait_time_us).
This is preventing the governor or the cpufreq driver to account for
I/O wait and thus use the right pstate
Signed-off-by: Stephane Gasparini <stephane.gasparini@linux.intel.com>
Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
When a storage device rejects a WRITE SAME command we will disable write
same functionality for the device and return -EREMOTEIO to the block
layer. -EREMOTEIO will in turn prevent DM from retrying the I/O and/or
failing the path.
Yiwen Jiang discovered a small race where WRITE SAME requests issued
simultaneously would cause -EIO to be returned. This happened because
any requests being prepared after WRITE SAME had been disabled for the
device caused us to return BLKPREP_KILL. The latter caused the block
layer to return -EIO upon completion.
To overcome this we introduce BLKPREP_INVALID which indicates that this
is an invalid request for the device. blk_peek_request() is modified to
return -EREMOTEIO in that case.
Reported-by: Yiwen Jiang <jiangyiwen@huawei.com>
Suggested-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Currently we don't allow sync workload of one cgroup to preempt sync
workload of any other cgroup. This is because we want to achieve service
separation between cgroups. However in cases where cgroup preempting is
ancestor of the current cgroup, there is no need of separation and
idling introduces unnecessary overhead. This hurts for example the case
when workload is isolated within a cgroup but journalling threads are in
root cgroup. Simple way to demostrate the issue is using:
dbench4 -c /usr/share/dbench4/client.txt -t 10 -D /mnt 1
on ext4 filesystem on plain SATA drive (mounted with barrier=0 to make
difference more visible). When all processes are in the root cgroup,
reported throughput is 153.132 MB/sec. When dbench process gets its own
blkio cgroup, reported throughput drops to 26.1006 MB/sec.
Fix the problem by making check in cfq_should_preempt() more benevolent
and allow preemption by ancestor cgroup. This improves the throughput
reported by dbench4 to 48.9106 MB/sec.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The original idea with preemption of sync noidle queues (introduced in
commit 718eee0579 "cfq-iosched: fairness for sync no-idle queues") was
that we service all sync noidle queues together, we don't idle on any of
the queues individually and we idle only if there is no sync noidle
queue to be served. This intention also matches the original test:
if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD
&& new_cfqq->service_tree == cfqq->service_tree)
return true;
However since at that time cfqq->service_tree was not set for idling
queues, this test was unreliable and was replaced in commit e4a229196a
"cfq-iosched: fix no-idle preemption logic" by:
if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD &&
cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD &&
new_cfqq->service_tree->count == 1)
return true;
That was a reliable test but was actually doing something different -
now we preempt sync noidle queue only if the new queue is the only one
busy in the service tree.
These days cfq queue is kept in service tree even if it is idling and
thus the original check would be safe again. But since we actually check
that cfq queues are in the same cgroup, of the same priority class and
workload type (sync noidle), we know that new_cfqq is fine to preempt
cfqq. So just remove the service tree check.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Move check for preemption by rt class up. There is no functional change
but it makes arguing about conditions simpler since we can be sure both
cfq queues are from the same ioprio class.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
There is no point in idling on a cfq group if the only cfq queue that is
there has too big thinktime.
Signed-off-by: Jan Kara <jack@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull libnvdimm fixes from Dan Williams:
"1/ Fixes to the libnvdimm 'pfn' device that establishes a reserved
area for storing a struct page array.
2/ Fixes for dax operations on a raw block device to prevent pagecache
collisions with dax mappings.
3/ A fix for pfn_t usage in vm_insert_mixed that lead to a null
pointer de-reference.
These have received build success notification from the kbuild robot
across 153 configs and pass the latest ndctl tests"
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
phys_to_pfn_t: use phys_addr_t
mm: fix pfn_t to page conversion in vm_insert_mixed
block: use DAX for partition table reads
block: revert runtime dax control of the raw block device
fs, block: force direct-I/O for dax-enabled block devices
devm_memremap_pages: fix vmem_altmap lifetime + alignment handling
libnvdimm, pfn: fix restoring memmap location
libnvdimm: fix mode determination for e820 devices
Avoid populating pagecache when the block device is in DAX mode.
Otherwise these page cache entries collide with the fsync/msync
implementation and break data durability guarantees.
Cc: Jan Kara <jack@suse.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Dynamically enabling DAX requires that the page cache first be flushed
and invalidated. This must occur atomically with the change of DAX mode
otherwise we confuse the fsync/msync tracking and violate data
durability guarantees. Eliminate the possibilty of DAX-disabled to
DAX-enabled transitions for now and revisit this for the next cycle.
Cc: Jan Kara <jack@suse.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Pull block layer fix from Jens Axboe:
"This just contains the fix for the split issue that we had in -rc1.
It's been well tested at this point, so let's get it in mainline so we
don't have the same split issue for -rc2"
* 'for-linus' of git://git.kernel.dk/linux-block:
block: fix bio splitting on max sectors
- Remove usage of ib_query_device and instead store attributes in
ib_device struct
- Move iopoll out of block and into lib, rename to irqpoll, and use
in several places in the rdma stack as our new completion queue
polling library mechanism. Update the other block drivers that
already used iopoll to use the new mechanism too.
- Replace the per-entry GID table locks with a single GID table lock
- IPoIB multicast cleanup
- Cleanups to the IB MR facility
- Add support for 64bit extended IB counters
- Fix for netlink oops while parsing RDMA nl messages
- RoCEv2 support for the core IB code
- mlx4 RoCEv2 support
- mlx5 RoCEv2 support
- Cross Channel support for mlx5
- Timestamp support for mlx5
- Atomic support for mlx5
- Raw QP support for mlx5
- MAINTAINERS update for mlx4/mlx5
- Misc ocrdma, qib, nes, usNIC, cxgb3, cxgb4, mlx4, mlx5 updates
- Add support for remote invalidate to the iSER driver (pushed through the
RDMA tree due to dependencies, acknowledged by nab)
- Update to NFSoRDMA (pushed through the RDMA tree due to dependencies,
acknowledged by Bruce)
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma
Pull rdma updates from Doug Ledford:
"Initial roundup of 4.5 merge window patches
- Remove usage of ib_query_device and instead store attributes in
ib_device struct
- Move iopoll out of block and into lib, rename to irqpoll, and use
in several places in the rdma stack as our new completion queue
polling library mechanism. Update the other block drivers that
already used iopoll to use the new mechanism too.
- Replace the per-entry GID table locks with a single GID table lock
- IPoIB multicast cleanup
- Cleanups to the IB MR facility
- Add support for 64bit extended IB counters
- Fix for netlink oops while parsing RDMA nl messages
- RoCEv2 support for the core IB code
- mlx4 RoCEv2 support
- mlx5 RoCEv2 support
- Cross Channel support for mlx5
- Timestamp support for mlx5
- Atomic support for mlx5
- Raw QP support for mlx5
- MAINTAINERS update for mlx4/mlx5
- Misc ocrdma, qib, nes, usNIC, cxgb3, cxgb4, mlx4, mlx5 updates
- Add support for remote invalidate to the iSER driver (pushed
through the RDMA tree due to dependencies, acknowledged by nab)
- Update to NFSoRDMA (pushed through the RDMA tree due to
dependencies, acknowledged by Bruce)"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (169 commits)
IB/mlx5: Unify CQ create flags check
IB/mlx5: Expose Raw Packet QP to user space consumers
{IB, net}/mlx5: Move the modify QP operation table to mlx5_ib
IB/mlx5: Support setting Ethernet priority for Raw Packet QPs
IB/mlx5: Add Raw Packet QP query functionality
IB/mlx5: Add create and destroy functionality for Raw Packet QP
IB/mlx5: Refactor mlx5_ib_qp to accommodate other QP types
IB/mlx5: Allocate a Transport Domain for each ucontext
net/mlx5_core: Warn on unsupported events of QP/RQ/SQ
net/mlx5_core: Add RQ and SQ event handling
net/mlx5_core: Export transport objects
IB/mlx5: Expose CQE version to user-space
IB/mlx5: Add CQE version 1 support to user QPs and SRQs
IB/mlx5: Fix data validation in mlx5_ib_alloc_ucontext
IB/sa: Fix netlink local service GFP crash
IB/srpt: Remove redundant wc array
IB/qib: Improve ipoib UD performance
IB/mlx4: Advertise RoCE v2 support
IB/mlx4: Create and use another QP1 for RoCEv2
IB/mlx4: Enable send of RoCE QP1 packets with IP/UDP headers
...
After commit e36f62042880(block: split bios to maxpossible length),
bio can be splitted in the middle of a vector entry, then it
is easy to split out one bio which size isn't aligned with block
size, especially when the block size is bigger than 512.
This patch fixes the issue by making the max io size aligned
to logical block size.
Fixes: e36f62042880(block: split bios to maxpossible length)
Reported-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Cc: Keith Busch <keith.busch@intel.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).
Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull NVMe updates from Jens Axboe:
"Last branch for this series is the nvme changes. It's in a separate
branch to avoid splitting too much between core and NVMe changes,
since NVMe is still helping drive some blk-mq changes. That said, not
a huge amount of core changes in here. The grunt of the work is the
continued split of the code"
* 'for-4.5/nvme' of git://git.kernel.dk/linux-block: (67 commits)
uapi: update install list after nvme.h rename
NVMe: Export NVMe attributes to sysfs group
NVMe: Shutdown controller only for power-off
NVMe: IO queue deletion re-write
NVMe: Remove queue freezing on resets
NVMe: Use a retryable error code on reset
NVMe: Fix admin queue ring wrap
nvme: make SG_IO support optional
nvme: fixes for NVME_IOCTL_IO_CMD on the char device
nvme: synchronize access to ctrl->namespaces
nvme: Move nvme_freeze/unfreeze_queues to nvme core
PCI/AER: include header file
NVMe: Export namespace attributes to sysfs
NVMe: Add pci error handlers
block: remove REQ_NO_TIMEOUT flag
nvme: merge iod and cmd_info
nvme: meta_sg doesn't have to be an array
nvme: properly free resources for cancelled command
nvme: simplify completion handling
nvme: special case AEN requests
...
Pull core block updates from Jens Axboe:
"We don't have a lot of core changes this time around, it's mostly in
drivers, which will come in a subsequent pull.
The cores changes include:
- blk-mq
- Prep patch from Christoph, changing blk_mq_alloc_request() to
take flags instead of just using gfp_t for sleep/nosleep.
- Doc patch from me, clarifying the difference between legacy
and blk-mq for timer usage.
- Fixes from Raghavendra for memory-less numa nodes, and a reuse
of CPU masks.
- Cleanup from Geliang Tang, using offset_in_page() instead of open
coding it.
- From Ilya, rename request_queue slab to it reflects what it holds,
and a fix for proper use of bdgrab/put.
- A real fix for the split across stripe boundaries from Keith. We
yanked a broken version of this from 4.4-rc final, this one works.
- From Mike Krinkin, emit a trace message when we split.
- From Wei Tang, two small cleanups, not explicitly clearing memory
that is already cleared"
* 'for-4.5/core' of git://git.kernel.dk/linux-block:
block: use bd{grab,put}() instead of open-coding
block: split bios to max possible length
block: add call to split trace point
blk-mq: Avoid memoryless numa node encoded in hctx numa_node
blk-mq: Reuse hardware context cpumask for tags
blk-mq: add a flags parameter to blk_mq_alloc_request
Revert "blk-flush: Queue through IO scheduler when flush not required"
block: clarify blk_add_timer() use case for blk-mq
bio: use offset_in_page macro
block: do not initialise statics to 0 or NULL
block: do not initialise globals to 0 or NULL
block: rename request_queue slab cache
1/ Media error handling: The 'badblocks' implementation that originated
in md-raid is up-levelled to a generic capability of a block device.
This initial implementation is limited to being consulted in the pmem
block-i/o path. Later, 'badblocks' will be consulted when creating
dax mappings.
2/ Raw block device dax: For virtualization and other cases that want
large contiguous mappings of persistent memory, add the capability to
dax-mmap a block device directly.
3/ Increased /dev/mem restrictions: Add an option to treat all io-memory
as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access while a driver is
actively using an address range. This behavior is controlled via the
new CONFIG_IO_STRICT_DEVMEM option and can be overridden by the
existing "iomem=relaxed" kernel command line option.
4/ Miscellaneous fixes include a 'pfn'-device huge page alignment fix,
block device shutdown crash fix, and other small libnvdimm fixes.
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Merge tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Dan Williams:
"The bulk of this has appeared in -next and independently received a
build success notification from the kbuild robot. The 'for-4.5/block-
dax' topic branch was rebased over the weekend to drop the "block
device end-of-life" rework that Al would like to see re-implemented
with a notifier, and to address bug reports against the badblocks
integration.
There is pending feedback against "libnvdimm: Add a poison list and
export badblocks" received last week. Linda identified some localized
fixups that we will handle incrementally.
Summary:
- Media error handling: The 'badblocks' implementation that
originated in md-raid is up-levelled to a generic capability of a
block device. This initial implementation is limited to being
consulted in the pmem block-i/o path. Later, 'badblocks' will be
consulted when creating dax mappings.
- Raw block device dax: For virtualization and other cases that want
large contiguous mappings of persistent memory, add the capability
to dax-mmap a block device directly.
- Increased /dev/mem restrictions: Add an option to treat all
io-memory as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access
while a driver is actively using an address range. This behavior
is controlled via the new CONFIG_IO_STRICT_DEVMEM option and can be
overridden by the existing "iomem=relaxed" kernel command line
option.
- Miscellaneous fixes include a 'pfn'-device huge page alignment fix,
block device shutdown crash fix, and other small libnvdimm fixes"
* tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (32 commits)
block: kill disk_{check|set|clear|alloc}_badblocks
libnvdimm, pmem: nvdimm_read_bytes() badblocks support
pmem, dax: disable dax in the presence of bad blocks
pmem: fail io-requests to known bad blocks
libnvdimm: convert to statically allocated badblocks
libnvdimm: don't fail init for full badblocks list
block, badblocks: introduce devm_init_badblocks
block: clarify badblocks lifetime
badblocks: rename badblocks_free to badblocks_exit
libnvdimm, pmem: move definition of nvdimm_namespace_add_poison to nd.h
libnvdimm: Add a poison list and export badblocks
nfit_test: Enable DSMs for all test NFITs
md: convert to use the generic badblocks code
block: Add badblock management for gendisks
badblocks: Add core badblock management code
block: fix del_gendisk() vs blkdev_ioctl crash
block: enable dax for raw block devices
block: introduce bdev_file_inode()
restrict /dev/mem to idle io memory ranges
arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug
...
This splits bio in the middle of a vector to form the largest possible
bio at the h/w's desired alignment, and guarantees the bio being split
will have some data.
The criteria for splitting is changed from the max sectors to the h/w's
optimal sector alignment if it is provided. For h/w that advertise their
block storage's underlying chunk size, it's a big performance win to not
submit commands that cross them. If sector alignment is not provided,
this patch uses the max sectors as before.
This addresses the performance issue commit d380561113 attempted to
fix, but was reverted due to splitting logic error.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: <stable@vger.kernel.org> # 4.4.x-
Signed-off-by: Jens Axboe <axboe@fb.com>
Longer term teach dax to punch "error" holes in mapping requests and
deliver SIGBUS to applications that consume a bad pmem page. For now,
simply disable the dax performance optimization in the presence of known
errors.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Provide a devres interface for initializing a badblocks instance. The
pmem driver has several scenarios where it will be beneficial to have
this structure automatically freed when the device is disabled / fails
probe.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The badblocks list attached to a gendisk is allocated by the driver
which equates to the driver owning the lifetime of the object. Do not
automatically free it in del_gendisk(). This is in preparation for
expanding the use of badblocks in libnvdimm drivers and introducing
devm_init_badblocks().
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
For symmetry with badblocks_init() make it clear that this path only
destroys incremental allocations of a badblocks instance, and does not
free the badblocks instance itself.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
NVDIMM devices, which can behave more like DRAM rather than block
devices, may develop bad cache lines, or 'poison'. A block device
exposed by the pmem driver can then consume poison via a read (or
write), and cause a machine check. On platforms without machine
check recovery features, this would mean a crash.
The block device maintaining a runtime list of all known sectors that
have poison can directly avoid this, and also provide a path forward
to enable proper handling/recovery for DAX faults on such a device.
Use the new badblock management interfaces to add a badblocks list to
gendisks.
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Take the core badblocks implementation from md, and make it generally
available. This follows the same style as kernel implementations of
linked lists, rb-trees etc, where you can have a structure that can be
embedded anywhere, and accessor functions to manipulate the data.
The only changes in this copy of the code are ones to generalize
function/variable names from md-specific ones. Also add init and free
functions.
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
When tearing down a block device early in its lifetime, userspace may
still be performing discovery actions like blkdev_ioctl() to re-read
partitions.
The nvdimm_revalidate_disk() implementation depends on
disk->driverfs_dev to be valid at entry. However, it is set to NULL in
del_gendisk() and fatally this is happening *before* the disk device is
deleted from userspace view.
There's no reason for del_gendisk() to clear ->driverfs_dev. That
device is the parent of the disk. It is guaranteed to not be freed
until the disk, as a child, drops its ->parent reference.
We could also fix this issue locally in nvdimm_revalidate_disk() by
using disk_to_dev(disk)->parent, but lets fix it globally since
->driverfs_dev follows the lifetime of the parent. Longer term we
should probably just add a @parent parameter to add_disk(), and stop
carrying this pointer in the gendisk.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffffa00340a8>] nvdimm_revalidate_disk+0x18/0x90 [libnvdimm]
CPU: 2 PID: 538 Comm: systemd-udevd Tainted: G O 4.4.0-rc5 #2257
[..]
Call Trace:
[<ffffffff8143e5c7>] rescan_partitions+0x87/0x2c0
[<ffffffff810f37f9>] ? __lock_is_held+0x49/0x70
[<ffffffff81438c62>] __blkdev_reread_part+0x72/0xb0
[<ffffffff81438cc5>] blkdev_reread_part+0x25/0x40
[<ffffffff8143982d>] blkdev_ioctl+0x4fd/0x9c0
[<ffffffff811246c9>] ? current_kernel_time64+0x69/0xd0
[<ffffffff812916dd>] block_ioctl+0x3d/0x50
[<ffffffff81264c38>] do_vfs_ioctl+0x308/0x560
[<ffffffff8115dbd1>] ? __audit_syscall_entry+0xb1/0x100
[<ffffffff810031d6>] ? do_audit_syscall_entry+0x66/0x70
[<ffffffff81264f09>] SyS_ioctl+0x79/0x90
[<ffffffff81902672>] entry_SYSCALL_64_fastpath+0x12/0x76
Reported-by: Robert Hu <robert.hu@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
If an application wants exclusive access to all of the persistent memory
provided by an NVDIMM namespace it can use this raw-block-dax facility
to forgo establishing a filesystem. This capability is targeted
primarily to hypervisors wanting to provision persistent memory for
guests. It can be disabled / enabled dynamically via the new BLKDAXSET
ioctl.
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reviewed-by: Jan Kara <jack@suse.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This reverts commit d380561113.
If we end up splitting on the first segment, we don't adjust
the sector count. That results in hitting a BUG() with attempting
to split 0 sectors.
As this is just a performance issue and not a regression since
4.3 release, let's just rever this change. That gives us more
time to test a real fix for 4.5, which would be marked for
stable anyway.
We currently only have an inline/sync helper to restart a stopped
queue. If drivers need an async version, they have to roll their
own. Add a generic helper instead.
Signed-off-by: Jens Axboe <axboe@fb.com>
For h/w that advertise their block storage's underlying chunk size, it's
a big performance win to not submit commands that cross them. This patch
uses that criteria if it is provided. If it is not provided, this patch
uses the max sectors as before.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull block layer fixes from Jens Axboe:
"Three small fixes for 4.4 final. Specifically:
- The segment issue fix from Junichi, where the old IO path does a
bio limit split before potentially bouncing the pages. We need to
do that in the right order, to ensure that limitations are met.
- A NVMe surprise removal IO hang fix from Keith.
- A use-after-free in null_blk, introduced by a previous patch in
this series. From Mike Krinkin"
* 'for-linus' of git://git.kernel.dk/linux-block:
null_blk: fix use-after-free error
block: ensure to split after potentially bouncing a bio
NVMe: IO ending fixes on surprise removal
blk_queue_bio() does split then bounce, which makes the segment
counting based on pages before bouncing and could go wrong. Move
the split to after bouncing, like we do for blk-mq, and the we
fix the issue of having the bio count for segments be wrong.
Fixes: 54efd50bfd ("block: make generic_make_request handle arbitrarily sized bios")
Cc: stable@vger.kernel.org
Tested-by: Artem S. Tashkinov <t.artem@lycos.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This was added for the 'magic' AEN requests in the NVMe driver that never
return. We now handle them purely inside the driver and don't need this
core hack any more.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Timer context is not very useful for drivers to perform any meaningful abort
action from. So instead of calling the driver from this useless context
defer it to a workqueue as soon as possible.
Note that while a delayed_work item would seem the right thing here I didn't
dare to use it due to the magic in blk_add_timer that pokes deep into timer
internals. But maybe this encourages Tejun to add a sensible API for that to
the workqueue API and we'll all be fine in the end :)
Contains a major update from Keith Bush:
"This patch removes synchronizing the timeout work so that the timer can
start a freeze on its own queue. The timer enters the queue, so timer
context can only start a freeze, but not wait for frozen."
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull block layer fixes from Jens Axboe:
"A set of fixes for the current series. This contains:
- A bunch of fixes for lightnvm, should be the last round for this
series. From Matias and Wenwei.
- A writeback detach inode fix from Ilya, also marked for stable.
- A block (though it says SCSI) fix for an OOPS in SCSI runtime power
management.
- Module init error path fixes for null_blk from Minfei"
* 'for-linus' of git://git.kernel.dk/linux-block:
null_blk: Fix error path in module initialization
lightnvm: do not compile in debugging by default
lightnvm: prevent gennvm module unload on use
lightnvm: fix media mgr registration
lightnvm: replace req queue with nvmdev for lld
lightnvm: comments on constants
lightnvm: check mm before use
lightnvm: refactor spin_unlock in gennvm_get_blk
lightnvm: put blks when luns configure failed
lightnvm: use flags in rrpc_get_blk
block: detach bdev inode from its wb in __blkdev_put()
SCSI: Fix NULL pointer dereference in runtime PM
The new name is irq_poll as iopoll is already taken. Better suggestions
welcome.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
We recently changed bio_integrity_alloc() to return ERR_PTRs instead of
NULL but these calls were missed.
Fixes: 06c1e3902a ('blk-integrity: empty implementation when disabled')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The following commit which went into mainline through networking tree
3b13758f51 ("cgroups: Allow dynamically changing net_classid")
conflicts in net/core/netclassid_cgroup.c with the following pending
fix in cgroup/for-4.4-fixes.
1f7dd3e5a6 ("cgroup: fix handling of multi-destination migration from subtree_control enabling")
The former separates out update_classid() from cgrp_attach() and
updates it to walk all fds of all tasks in the target css so that it
can be used from both migration and config change paths. The latter
drops @css from cgrp_attach().
Resolve the conflict by making cgrp_attach() call update_classid()
with the css from the first task. We can revive @tset walking in
cgrp_attach() but given that net_cls is v1 only where there always is
only one target css during migration, this is fine.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Nina Schiff <ninasc@fb.com>
This is quite a bumper crop of fixes: Three from Arnd correcting various build
issues in some configurations, a lock recursion in qla2xxx. Two potentially
exploitable issues in hpsa and mvsas, a potential null deref in st, A revert
of a bdi registration fix that turned out to cause even more problems, a set
of fixes to allow people who only defined MPT2SAS to still work after the
mpt2/mpt3sas merger and a couple of fixes for issues turned up by the hyper-v
storvsc driver.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"This is quite a bumper crop of fixes: three from Arnd correcting
various build issues in some configurations, a lock recursion in
qla2xxx. Two potentially exploitable issues in hpsa and mvsas, a
potential null deref in st, a revert of a bdi registration fix that
turned out to cause even more problems, a set of fixes to allow people
who only defined MPT2SAS to still work after the mpt2/mpt3sas merger
and a couple of fixes for issues turned up by the hyper-v storvsc
driver"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
mpt3sas: fix Kconfig dependency problem for mpt2sas back compatibility
Revert "scsi: Fix a bdi reregistration race"
mpt3sas: Add dummy Kconfig option for backwards compatibility
Fix a memory leak in scsi_host_dev_release()
block/sd: Fix device-imposed transfer length limits
scsi_debug: fix prevent_allow+verify regressions
MAINTAINERS: Add myself as co-maintainer of the SCSI subsystem.
sd: Make discard granularity match logical block size when LBPRZ=1
scsi: hpsa: select CONFIG_SCSI_SAS_ATTR
scsi: advansys needs ISA dma api for ISA support
scsi_sysfs: protect against double execution of __scsi_remove_device()
st: fix potential null pointer dereference.
scsi: report 'INQUIRY result too short' once per host
advansys: fix big-endian builds
qla2xxx: Fix rwlock recursion
hpsa: logical vs bitwise AND typo
mvsas: don't allow negative timeouts
mpt3sas: Fix use sas_is_tlr_enabled API before enabling MPI2_SCSIIO_CONTROL_TLR_ON flag
The routines in scsi_pm.c assume that if a runtime-PM callback is
invoked for a SCSI device, it can only mean that the device's driver
has asked the block layer to handle the runtime power management (by
calling blk_pm_runtime_init(), which among other things sets q->dev).
However, this assumption turns out to be wrong for things like the ses
driver. Normally ses devices are not allowed to do runtime PM, but
userspace can override this setting. If this happens, the kernel gets
a NULL pointer dereference when blk_post_runtime_resume() tries to use
the uninitialized q->dev pointer.
This patch fixes the problem by checking q->dev in block layer before
handle runtime PM. Since ses doesn't define any PM callbacks and call
blk_pm_runtime_init(), the crash won't occur.
This fixes Bugzilla #101371.
https://bugzilla.kernel.org/show_bug.cgi?id=101371
More discussion can be found from below link.
http://marc.info/?l=linux-scsi&m=144163730531875&w=2
Signed-off-by: Ken Xue <Ken.Xue@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Xiangliang Yu <Xiangliang.Yu@amd.com>
Cc: James E.J. Bottomley <JBottomley@odin.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Terry <Michael.terry@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
There is a split tracepoint that is supposed to be called when
bio is splitted, and it was called in bio_split function until
commit 4b1faf9316 ("block: Kill bio_pair_split()").
But now, no one reports splits, so this patch adds call to
trace_block_split back in blk_queue_split right after split.
Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
In architecture like powerpc, we can have cpus without any local memory
attached to it (a.k.a memoryless nodes). In such cases cpu to node mapping
can result in memory allocation hints for block hctx->numa_node populated
with node values which does not have real memory.
Instead use local_memory_node(), which is guaranteed to have memory.
local_memory_node is a noop in other architectures that does not support
memoryless nodes.
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
hctx->cpumask is already populated and let the tag cpumask follow that
instead of going through a new for loop.
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This patch moves the blk_integrity_payload definition outside the
CONFIG_BLK_DEV_INTERITY dependency and provides empty function
implementations when the kernel configuration disables integrity
extensions. This simplifies drivers that make use of these to map user
data so they don't need to repeat the same configuration checks.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Updated by Jens to pass an error pointer return from
bio_integrity_alloc(), otherwise if CONFIG_BLK_DEV_INTEGRITY isn't
set, we return a weird ENOMEM from __nvme_submit_user_cmd()
if a meta buffer is set.
Signed-off-by: Jens Axboe <axboe@fb.com>
Consider the following v2 hierarchy.
P0 (+memory) --- P1 (-memory) --- A
\- B
P0 has memory enabled in its subtree_control while P1 doesn't. If
both A and B contain processes, they would belong to the memory css of
P1. Now if memory is enabled on P1's subtree_control, memory csses
should be created on both A and B and A's processes should be moved to
the former and B's processes the latter. IOW, enabling controllers
can cause atomic migrations into different csses.
The core cgroup migration logic has been updated accordingly but the
controller migration methods haven't and still assume that all tasks
migrate to a single target css; furthermore, the methods were fed the
css in which subtree_control was updated which is the parent of the
target csses. pids controller depends on the migration methods to
move charges and this made the controller attribute charges to the
wrong csses often triggering the following warning by driving a
counter negative.
WARNING: CPU: 1 PID: 1 at kernel/cgroup_pids.c:97 pids_cancel.constprop.6+0x31/0x40()
Modules linked in:
CPU: 1 PID: 1 Comm: systemd Not tainted 4.4.0-rc1+ #29
...
ffffffff81f65382 ffff88007c043b90 ffffffff81551ffc 0000000000000000
ffff88007c043bc8 ffffffff810de202 ffff88007a752000 ffff88007a29ab00
ffff88007c043c80 ffff88007a1d8400 0000000000000001 ffff88007c043bd8
Call Trace:
[<ffffffff81551ffc>] dump_stack+0x4e/0x82
[<ffffffff810de202>] warn_slowpath_common+0x82/0xc0
[<ffffffff810de2fa>] warn_slowpath_null+0x1a/0x20
[<ffffffff8118e031>] pids_cancel.constprop.6+0x31/0x40
[<ffffffff8118e0fd>] pids_can_attach+0x6d/0xf0
[<ffffffff81188a4c>] cgroup_taskset_migrate+0x6c/0x330
[<ffffffff81188e05>] cgroup_migrate+0xf5/0x190
[<ffffffff81189016>] cgroup_attach_task+0x176/0x200
[<ffffffff8118949d>] __cgroup_procs_write+0x2ad/0x460
[<ffffffff81189684>] cgroup_procs_write+0x14/0x20
[<ffffffff811854e5>] cgroup_file_write+0x35/0x1c0
[<ffffffff812e26f1>] kernfs_fop_write+0x141/0x190
[<ffffffff81265f88>] __vfs_write+0x28/0xe0
[<ffffffff812666fc>] vfs_write+0xac/0x1a0
[<ffffffff81267019>] SyS_write+0x49/0xb0
[<ffffffff81bcef32>] entry_SYSCALL_64_fastpath+0x12/0x76
This patch fixes the bug by removing @css parameter from the three
migration methods, ->can_attach, ->cancel_attach() and ->attach() and
updating cgroup_taskset iteration helpers also return the destination
css in addition to the task being migrated. All controllers are
updated accordingly.
* Controllers which don't care whether there are one or multiple
target csses can be converted trivially. cpu, io, freezer, perf,
netclassid and netprio fall in this category.
* cpuset's current implementation assumes that there's single source
and destination and thus doesn't support v2 hierarchy already. The
only change made by this patchset is how that single destination css
is obtained.
* memory migration path already doesn't do anything on v2. How the
single destination css is obtained is updated and the prep stage of
mem_cgroup_can_attach() is reordered to accomodate the change.
* pids is the only controller which was affected by this bug. It now
correctly handles multi-destination migrations and no longer causes
counter underflow from incorrect accounting.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Aleksa Sarai <cyphar@cyphar.com>
We already have the reserved flag, and a nowait flag awkwardly encoded as
a gfp_t. Add a real flags argument to make the scheme more extensible and
allow for a nicer calling convention.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
When bio has only one physical segment, we should set bio's
bi_seg_front_size as the real(final) size of the single segment.
Fixes: 02e707424c2ea(blk-merge: fix blk_bio_segment_split)
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
When a cloned request is retried on other queues it always needs
to be checked against the queue limits of that queue.
Otherwise the calculations for nr_phys_segments might be wrong,
leading to a crash in scsi_init_sgtable().
To clarify this the patch renames blk_rq_check_limits()
to blk_cloned_rq_check_limits() and removes the symbol
export, as the new function should only be used for
cloned requests and never exported.
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Ewan Milne <emilne@redhat.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Fixes: e2a60da74 ("block: Clean up special command handling logic")
Cc: stable@vger.kernel.org # 3.7+
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Today, blockdev --rereadpt /dev/sda will fail with EBUSY if any
partition of sda is mounted (and will fail with EINVAL if pointed
at a partition). But it will pass if the entire block device is
formatted with a filesystem and mounted. I don't think this makes
sense; partitioning should surely not ever change out from under
a mounted device.
So check for bdev->bd_super, and fail that with -EBUSY as well.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit 4f258a4634 ("sd: Fix maximum I/O size for BLOCK_PC requests")
had the unfortunate side-effect of removing an implicit clamp to
BLK_DEF_MAX_SECTORS for REQ_TYPE_FS requests in the block layer
code. This caused problems for some SMR drives.
Debugging this issue revealed a few problems with the existing
infrastructure since the block layer didn't know how to deal with
device-imposed limits, only limits set by the I/O controller.
- Introduce a new queue limit, max_dev_sectors, which is used by the
ULD to signal the maximum sectors for a REQ_TYPE_FS request.
- Ensure that max_dev_sectors is correctly stacked and taken into
account when overriding max_sectors through sysfs.
- Rework sd_read_block_limits() so it saves the max_xfer and opt_xfer
values for later processing.
- In sd_revalidate() set the queue's max_dev_sectors based on the
MAXIMUM TRANSFER LENGTH value in the Block Limits VPD. If this value
is not reported, fall back to a cap based on the CDB TRANSFER LENGTH
field size.
- In sd_revalidate(), use OPTIMAL TRANSFER LENGTH from the Block Limits
VPD--if reported and sane--to signal the preferred device transfer
size for FS requests. Otherwise use BLK_DEF_MAX_SECTORS.
- blk_limits_max_hw_sectors() is no longer used and can be removed.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=93581
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: sweeneygj@gmx.com
Tested-by: Arzeets <anatol.pomozov@gmail.com>
Tested-by: David Eisner <david.eisner@oriel.oxon.org>
Tested-by: Mario Kicherer <dev@kicherer.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This reverts commit 1b2ff19e6a.
Jan writes:
--
Thanks for report! After some investigation I found out we allocate
elevator specific data in __get_request() only for non-flush requests. And
this is actually required since the flush machinery uses the space in
struct request for something else. Doh. So my patch is just wrong and not
easy to fix since at the time __get_request() is called we are not sure
whether the flush machinery will be used in the end. Jens, please revert
1b2ff19e6a. Thanks!
I'm somewhat surprised that you can reliably hit the race where flushing
gets disabled for the device just while the request is in flight. But I
guess during boot it makes some sense.
--
So let's just revert it, we can fix the queue run manually after the
fact. This race is rare enough that it didn't trigger in testing, it
requires the specific disable-while-in-flight scenario to trigger.
This reverts commit 1b2ff19e6a.
Jan writes:
--
Thanks for report! After some investigation I found out we allocate
elevator specific data in __get_request() only for non-flush requests. And
this is actually required since the flush machinery uses the space in
struct request for something else. Doh. So my patch is just wrong and not
easy to fix since at the time __get_request() is called we are not sure
whether the flush machinery will be used in the end. Jens, please revert
1b2ff19e6a. Thanks!
I'm somewhat surprised that you can reliably hit the race where flushing
gets disabled for the device just while the request is in flight. But I
guess during boot it makes some sense.
--
So let's just revert it, we can fix the queue run manually after the
fact. This race is rare enough that it didn't trigger in testing, it
requires the specific disable-while-in-flight scenario to trigger.
Just a comment update on not needing queue_lock, and that we aren't
really adding the request to a timeout list for !mq.
Signed-off-by: Jens Axboe <axboe@fb.com>
This patch fixes the checkpatch.pl error to genhd.c:
ERROR: do not initialise statics to 0 or NULL
Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This patch fixes the checkpatch.pl error to blk-exec.c:
ERROR: do not initialise globals to 0 or NULL
Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
We only added the request to the request list for the !blk-mq case,
so we should only delete it in that case as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull block layer fixes from Jens Axboe:
"A round of fixes/updates for the current series.
This looks a little bigger than it is, but that's mainly because we
pushed the lightnvm enabled null_blk change out of the merge window so
it could be updated a bit. The rest of the volume is also mostly
lightnvm. In particular:
- Lightnvm. Various fixes, additions, updates from Matias and
Javier, as well as from Wenwei Tao.
- NVMe:
- Fix for potential arithmetic overflow from Keith.
- Also from Keith, ensure that we reap pending completions from
a completion queue before deleting it. Fixes kernel crashes
when resetting a device with IO pending.
- Various little lightnvm related tweaks from Matias.
- Fixup flushes to go through the IO scheduler, for the cases where a
flush is not required. Fixes a case in CFQ where we would be
idling and not see this request, hence not break the idling. From
Jan Kara.
- Use list_{first,prev,next} in elevator.c for cleaner code. From
Gelian Tang.
- Fix for a warning trigger on btrfs and raid on single queue blk-mq
devices, where we would flush plug callbacks with preemption
disabled. From me.
- A mac partition validation fix from Kees Cook.
- Two merge fixes from Ming, marked stable. A third part is adding a
new warning so we'll notice this quicker in the future, if we screw
up the accounting.
- Cleanup of thread name/creation in mtip32xx from Rasmus Villemoes"
* 'for-linus' of git://git.kernel.dk/linux-block: (32 commits)
blk-merge: warn if figured out segment number is bigger than nr_phys_segments
blk-merge: fix blk_bio_segment_split
block: fix segment split
blk-mq: fix calling unplug callbacks with preempt disabled
mac: validate mac_partition is within sector
mtip32xx: use formatting capability of kthread_create_on_node
NVMe: reap completion entries when deleting queue
lightnvm: add free and bad lun info to show luns
lightnvm: keep track of block counts
nvme: lightnvm: use admin queues for admin cmds
lightnvm: missing free on init error
lightnvm: wrong return value and redundant free
null_blk: do not del gendisk with lightnvm
null_blk: use device addressing mode
null_blk: use ppa_cache pool
NVMe: Fix possible arithmetic overflow for max segments
blk-flush: Queue through IO scheduler when flush not required
null_blk: register as a LightNVM device
elevator: use list_{first,prev,next}_entry
lightnvm: cleanup queue before target removal
...
We had seen lots of reports of this kind issue, so add one
warnning in blk-merge, then it can be triggered easily and
avoid to depend on warning/bug from drivers.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit bdced438acd83a(block: setup bi_phys_segments after
splitting) introduces function of computing bio->bi_phys_segments
during bio splitting.
Unfortunately both bio->bi_seg_front_size and bio->bi_seg_back_size
arn't computed, so too many physical segments may be obtained
for one request since both the two are used to check if one segment
across two bios can be possible.
This patch fixes the issue by computing the two variables in
blk_bio_segment_split().
Fixes: bdced438acd83a(block: setup bi_phys_segments after splitting)
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Mark Salter <msalter@redhat.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Inside blk_bio_segment_split(), previous bvec pointer(bvprvp)
always points to the iterator local variable, which is obviously
wrong, so fix it by pointing to the local variable of 'bvprv'.
Fixes: 5014c311baa2b(block: fix bogus compiler warnings in blk-merge.c)
Cc: stable@kernel.org #4.3
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Mark Salter <msalter@redhat.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If md->signature == MAC_DRIVER_MAGIC and md->block_size == 1023, a single
512 byte sector would be read (secsize / 512). However the partition
structure would be located past the end of the buffer (secsize % 512).
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently blk_insert_flush() just adds flush request to q->queue_head
when flush is not required. That completely bypasses IO scheduler so
e.g. CFQ can be idling waiting for new request to arrive and will idle
through the whole window unnecessarily. Luckily this only happens in
rare cases as usually checks in generic_make_request_checks() clear
FLUSH and FUA flags early if they are not needed.
When no flushing is actually required, we can easily fix the problem by
properly queueing the request through the IO scheduler. Ideally IO
scheduler should be also made aware of requests queued via
blk_flush_queue_rq(). However inserting flush request through IO
scheduler can have unwanted side-effects since due to flush batching
delaying the flush request in IO scheduler will delay all flush requests
possibly coming from other processes. So we keep adding the request
directly to q->queue_head.
Signed-off-by: Jan Kara <jack@suse.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
To make the intention clearer, use list_{first,prev,next}_entry
instead of list_entry.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Fix kernel-doc warning in blk-core.c:
Warning(..//block/blk-core.c:1549): No description found for parameter 'same_queue_rq'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull block IO poll support from Jens Axboe:
"Various groups have been doing experimentation around IO polling for
(really) fast devices. The code has been reviewed and has been
sitting on the side for a few releases, but this is now good enough
for coordinated benchmarking and further experimentation.
Currently O_DIRECT sync read/write are supported. A framework is in
the works that allows scalable stats tracking so we can auto-tune
this. And we'll add libaio support as well soon. Fow now, it's an
opt-in feature for test purposes"
* 'for-4.4/io-poll' of git://git.kernel.dk/linux-block:
direct-io: be sure to assign dio->bio_bdev for both paths
directio: add block polling support
NVMe: add blk polling support
block: add block polling support
blk-mq: return tag/queue combo in the make_request_fn handlers
block: change ->make_request_fn() and users to return a queue cookie
Add basic support for polling for specific IO to complete. This uses
the cookie that blk-mq passes back, which enables the block layer
to pass this cookie to the driver to spin for a specific request.
This will be combined with request latency tracking, so we can make
qualified decisions about when to poll and when not to. For now, for
benchmark purposes, we add a sysfs file that controls whether polling
is enabled or not.
Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Return a cookie, blk_qc_t, from the blk-mq make request functions, that
allows a later caller to uniquely identify a specific IO. The cookie
doesn't mean anything to the caller, but the caller can use it to later
pass back to the block layer. The block layer can then identify the
hardware queue and request from that cookie.
Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
No functional changes in this patch, but it prepares us for returning
a more useful cookie related to the IO that was queued up.
Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
setpriority(PRIO_USER, 0, x) will change the priority of tasks outside of
the current pid namespace. This is in contrast to both the other modes of
setpriority and the example of kill(-1). Fix this. getpriority and
ioprio have the same failure mode, fix them too.
Eric said:
: After some more thinking about it this patch sounds justifiable.
:
: My goal with namespaces is not to build perfect isolation mechanisms
: as that can get into ill defined territory, but to build well defined
: mechanisms. And to handle the corner cases so you can use only
: a single namespace with well defined results.
:
: In this case you have found the two interfaces I am aware of that
: identify processes by uid instead of by pid. Which quite frankly is
: weird. Unfortunately the weird unexpected cases are hard to handle
: in the usual way.
:
: I was hoping for a little more information. Changes like this one we
: have to be careful of because someone might be depending on the current
: behavior. I don't think they are and I do think this make sense as part
: of the pid namespace.
Signed-off-by: Ben Segall <bsegall@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ambrose Feinstein <ambrose@google.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep. Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep. The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake. As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags. This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.
[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".
Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.
This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.
This patch then converts a number of sites
o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.
o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.
o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.
o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.
The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.
The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull cgroup updates from Tejun Heo:
"The cgroup core saw several significant updates this cycle:
- percpu_rwsem for threadgroup locking is reinstated. This was
temporarily dropped due to down_write latency issues. Oleg's
rework of percpu_rwsem which is scheduled to be merged in this
merge window resolves the issue.
- On the v2 hierarchy, when controllers are enabled and disabled, all
operations are atomic and can fail and revert cleanly. This allows
->can_attach() failure which is necessary for cpu RT slices.
- Tasks now stay associated with the original cgroups after exit
until released. This allows tracking resources held by zombies
(e.g. pids) and makes it easy to find out where zombies came from
on the v2 hierarchy. The pids controller was broken before these
changes as zombies escaped the limits; unfortunately, updating this
behavior required too many invasive changes and I don't think it's
a good idea to backport them, so the pids controller on 4.3, the
first version which included the pids controller, will stay broken
at least until I'm sure about the cgroup core changes.
- Optimization of a couple common tests using static_key"
* 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (38 commits)
cgroup: fix race condition around termination check in css_task_iter_next()
blkcg: don't create "io.stat" on the root cgroup
cgroup: drop cgroup__DEVEL__legacy_files_on_dfl
cgroup: replace error handling in cgroup_init() with WARN_ON()s
cgroup: add cgroup_subsys->free() method and use it to fix pids controller
cgroup: keep zombies associated with their original cgroups
cgroup: make css_set_rwsem a spinlock and rename it to css_set_lock
cgroup: don't hold css_set_rwsem across css task iteration
cgroup: reorganize css_task_iter functions
cgroup: factor out css_set_move_task()
cgroup: keep css_set and task lists in chronological order
cgroup: make cgroup_destroy_locked() test cgroup_is_populated()
cgroup: make css_sets pin the associated cgroups
cgroup: relocate cgroup_[try]get/put()
cgroup: move check_for_release() invocation
cgroup: replace cgroup_has_tasks() with cgroup_is_populated()
cgroup: make cgroup->nr_populated count the number of populated css_sets
cgroup: remove an unused parameter from cgroup_task_migrate()
cgroup: fix too early usage of static_branch_disable()
cgroup: make cgroup_update_dfl_csses() migrate all target processes atomically
...
Pull block reservation support from Jens Axboe:
"This adds support for persistent reservations, both at the core level,
as well as for sd and NVMe"
[ Background from the docs: "Persistent Reservations allow restricting
access to block devices to specific initiators in a shared storage
setup. All implementations are expected to ensure the reservations
survive a power loss and cover all connections in a multi path
environment" ]
* 'for-4.4/reservations' of git://git.kernel.dk/linux-block:
NVMe: Precedence error in nvme_pr_clear()
nvme: add missing endianess annotations in nvme_pr_command
NVMe: Add persistent reservation ops
sd: implement the Persistent Reservation API
block: add an API for Persistent Reservations
block: cleanup blkdev_ioctl
Pull block integrity updates from Jens Axboe:
""This is the joint work of Dan and Martin, cleaning up and improving
the support for block data integrity"
* 'for-4.4/integrity' of git://git.kernel.dk/linux-block:
block, libnvdimm, nvme: provide a built-in blk_integrity nop profile
block: blk_flush_integrity() for bio-based drivers
block: move blk_integrity to request_queue
block: generic request_queue reference counting
nvme: suspend i/o during runtime blk_integrity_unregister
md: suspend i/o during runtime blk_integrity_unregister
md, dm, scsi, nvme, libnvdimm: drop blk_integrity_unregister() at shutdown
block: Inline blk_integrity in struct gendisk
block: Export integrity data interval size in sysfs
block: Reduce the size of struct blk_integrity
block: Consolidate static integrity profile properties
block: Move integrity kobject to struct gendisk
Pull core block updates from Jens Axboe:
"This is the core block pull request for 4.4. I've got a few more
topic branches this time around, some of them will layer on top of the
core+drivers changes and will come in a separate round. So not a huge
chunk of changes in this round.
This pull request contains:
- Enable blk-mq page allocation tracking with kmemleak, from Catalin.
- Unused prototype removal in blk-mq from Christoph.
- Cleanup of the q->blk_trace exchange, using cmpxchg instead of two
xchg()'s, from Davidlohr.
- A plug flush fix from Jeff.
- Also from Jeff, a fix that means we don't have to update shared tag
sets at init time unless we do a state change. This cuts down boot
times on thousands of devices a lot with scsi/blk-mq.
- blk-mq waitqueue barrier fix from Kosuke.
- Various fixes from Ming:
- Fixes for segment merging and splitting, and checks, for
the old core and blk-mq.
- Potential blk-mq speedup by marking ctx pending at the end
of a plug insertion batch in blk-mq.
- direct-io no page dirty on kernel direct reads.
- A WRITE_SYNC fix for mpage from Roman"
* 'for-4.4/core' of git://git.kernel.dk/linux-block:
blk-mq: avoid excessive boot delays with large lun counts
blktrace: re-write setting q->blk_trace
blk-mq: mark ctx as pending at batch in flush plug path
blk-mq: fix for trace_block_plug()
block: check bio_mergeable() early before merging
blk-mq: check bio_mergeable() early before merging
block: avoid to merge splitted bio
block: setup bi_phys_segments after splitting
block: fix plug list flushing for nomerge queues
blk-mq: remove unused blk_mq_clone_flush_request prototype
blk-mq: fix waitqueue_active without memory barrier in block/blk-mq-tag.c
fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct read
fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write
block: kmemleak: Track the page allocations for struct request
Hi,
Zhangqing Luo reported long boot times on a system with thousands of
LUNs when scsi-mq was enabled. He narrowed the problem down to
blk_mq_add_queue_tag_set, where every queue is frozen in order to set
the BLK_MQ_F_TAG_SHARED flag. Each added device will freeze all queues
added before it in sequence, which involves waiting for an RCU grace
period for each one. We don't need to do this. After the second queue
is added, only new queues need to be initialized with the shared tag.
We can do that by percolating the flag up to the blk_mq_tag_set, and
updating the newly added queue's hctxs if the flag is set.
This problem was introduced by commit 0d2602ca30 (blk-mq: improve
support for shared tags maps).
Reported-and-tested-by: Jason Luo <zhangqing.luo@oracle.com>
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
In commit b49a087("block: remove split code in
blkdev_issue_{discard,write_same}"), discard_granularity and alignment
checks were removed. Ideally, with bio late splitting, the upper layers
shouldn't need to depend on device's limits.
Christoph reported a discard regression on the HGST Ultrastar SN100 NVMe
device when mkfs.xfs. We have not found the root cause yet.
This patch re-adds discard_granularity and alignment checks by reverting
the related changes in commit b49a087. The good thing is now we can
remove the 2G discard size cap and just use UINT_MAX to avoid bi_size
overflow.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The stat files on the root cgroup shows stats for the whole system and
usually don't contain any information which isn't available through
the usual system monitoring mechanisms. Some controllers skip
collecting these duplicate stats to optimize cases where cgroup isn't
used and later try to emulate the result on demand.
This leads to complexities and subtle differences in the information
shown through different channels. This is entirely unnecessary and
cgroup v2 is dropping stat files which are duplicate from all
controllers. This patch removes "io.stat" from the root hierarchy.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Vivek Goyal <vgoyal@redhat.com>
Most of times, flush plug should be the hottest I/O path,
so mark ctx as pending after all requests in the list are
inserted.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The trace point is for tracing plug event of each request
queue instead of each task, so we should check the request
count in the plug list from current queue instead of
current task.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
After bio splitting is introduced, one bio can be splitted
and it is marked as NOMERGE because it is too fat to be merged,
so check bio_mergeable() earlier to avoid to try to merge it
unnecessarily.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
It isn't necessary to try to merge the bio which is marked
as NOMERGE.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The splitted bio has been already too fat to merge, so mark it
as NOMERGE.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The number of bio->bi_phys_segments is always obtained
during bio splitting, so it is natural to setup it
just after bio splitting, then we can avoid to compute
nr_segment again during merge.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Request queues with merging disabled will not flush the plug list after
BLK_MAX_REQUEST_COUNT requests have been queued, since the code relies
on blk_attempt_plug_merge to compute the request_count. Fix this by
computing the number of queued requests even for nomerge queues.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commits adds a driver API and ioctls for controlling Persistent
Reservations s/genericly/generically/ at the block layer. Persistent
Reservations are supported by SCSI and NVMe and allow controlling who gets
access to a device in a shared storage setup.
Note that we add a pr_ops structure to struct block_device_operations
instead of adding the members directly to avoid bloating all instances
of devices that will never support Persistent Reservations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Split out helpers for all non-trivial ioctls to make this function simpler,
and also start passing around a pointer version of the argument, as that's
what most ioctl handlers actually need.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The libnvidmm-btt and nvme drivers use blk_integrity to reserve space
for per-sector metadata, but sometimes without protection checksums.
This property is generically useful, so teach the block core to
internally specify a nop profile if one is not provided at registration
time.
Cc: Keith Busch <keith.busch@intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
[hch: kill the local nvme nop profile as well]
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Since they lack requests to pin the request_queue active, synchronous
bio-based drivers may have in-flight integrity work from
bio_integrity_endio() that is not flushed by blk_freeze_queue(). Flush
that work to prevent races to free the queue and the final usage of the
blk_integrity profile.
This is temporary unless/until bio-based drivers start to generically
take a q_usage_counter reference while a bio is in-flight.
Cc: Martin K. Petersen <martin.petersen@oracle.com>
[martin: fix the CONFIG_BLK_DEV_INTEGRITY=n case]
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
A trace like the following proceeds a crash in bio_integrity_process()
when it goes to use an already freed blk_integrity profile.
BUG: unable to handle kernel paging request at ffff8800d31b10d8
IP: [<ffff8800d31b10d8>] 0xffff8800d31b10d8
PGD 2f65067 PUD 21fffd067 PMD 80000000d30001e3
Oops: 0011 [#1] SMP
Dumping ftrace buffer:
---------------------------------
ndctl-2222 2.... 44526245us : disk_release: pmem1s
systemd--2223 4.... 44573945us : bio_integrity_endio: pmem1s
<...>-409 4.... 44574005us : bio_integrity_process: pmem1s
---------------------------------
[..]
Call Trace:
[<ffffffff8144e0f9>] ? bio_integrity_process+0x159/0x2d0
[<ffffffff8144e4f6>] bio_integrity_verify_fn+0x36/0x60
[<ffffffff810bd2dc>] process_one_work+0x1cc/0x4e0
Given that a request_queue is pinned while i/o is in flight and that a
gendisk is allowed to have a shorter lifetime, move blk_integrity to
request_queue to satisfy requests arriving after the gendisk has been
torn down.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
[martin: fix the CONFIG_BLK_DEV_INTEGRITY=n case]
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Allow pmem, and other synchronous/bio-based block drivers, to fallback
on a per-cpu reference count managed by the core for tracking queue
live/dead state.
The existing per-cpu reference count for the blk_mq case is promoted to
be used in all block i/o scenarios. This involves initializing it by
default, waiting for it to drop to zero at exit, and holding a live
reference over the invocation of q->make_request_fn() in
generic_make_request(). The blk_mq code continues to take its own
reference per blk_mq request and retains the ability to freeze the
queue, but the check that the queue is frozen is moved to
generic_make_request().
This fixes crash signatures like the following:
BUG: unable to handle kernel paging request at ffff880140000000
[..]
Call Trace:
[<ffffffff8145e8bf>] ? copy_user_handle_tail+0x5f/0x70
[<ffffffffa004e1e0>] pmem_do_bvec.isra.11+0x70/0xf0 [nd_pmem]
[<ffffffffa004e331>] pmem_make_request+0xd1/0x200 [nd_pmem]
[<ffffffff811c3162>] ? mempool_alloc+0x72/0x1a0
[<ffffffff8141f8b6>] generic_make_request+0xd6/0x110
[<ffffffff8141f966>] submit_bio+0x76/0x170
[<ffffffff81286dff>] submit_bh_wbc+0x12f/0x160
[<ffffffff81286e62>] submit_bh+0x12/0x20
[<ffffffff813395bd>] jbd2_write_superblock+0x8d/0x170
[<ffffffff8133974d>] jbd2_mark_journal_empty+0x5d/0x90
[<ffffffff813399cb>] jbd2_journal_destroy+0x24b/0x270
[<ffffffff810bc4ca>] ? put_pwq_unlocked+0x2a/0x30
[<ffffffff810bc6f5>] ? destroy_workqueue+0x225/0x250
[<ffffffff81303494>] ext4_put_super+0x64/0x360
[<ffffffff8124ab1a>] generic_shutdown_super+0x6a/0xf0
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Up until now the_integrity profile has been dynamically allocated and
attached to struct gendisk after the disk has been made active.
This causes problems because NVMe devices need to register the profile
prior to the partition table being read due to a mandatory metadata
buffer requirement. In addition, DM goes through hoops to deal with
preallocating, but not initializing integrity profiles.
Since the integrity profile is small (4 bytes + a pointer), Christoph
suggested moving it to struct gendisk proper. This requires several
changes:
- Moving the blk_integrity definition to genhd.h.
- Inlining blk_integrity in struct gendisk.
- Removing the dynamic allocation code.
- Adding helper functions which allow gendisk to set up and tear down
the integrity sysfs dir when a disk is added/deleted.
- Adding a blk_integrity_revalidate() callback for updating the stable
pages bdi setting.
- The calls that depend on whether a device has an integrity profile or
not now key off of the bi->profile pointer.
- Simplifying the integrity support routines in DM (Mike Snitzer).
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The size of the data interval was not exported in the sysfs integrity
directory. Export it so that userland apps can tell whether the interval
is different from the device's logical block size.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The per-device properties in the blk_integrity structure were previously
unsigned short. However, most of the values fit inside a char. The only
exception is the data interval size and we can work around that by
storing it as a power of two.
This cuts the size of the dynamic portion of blk_integrity in half.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
We previously made a complete copy of a device's data integrity profile
even though several of the fields inside the blk_integrity struct are
pointers to fixed template entries in t10-pi.c.
Split the static and per-device portions so that we can reference the
template directly.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The integrity kobject purely exists to support the integrity
subdirectory in sysfs and doesn't really have anything to do with the
blk_integrity data structure. Move the kobject to struct gendisk where
it belongs.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
bdi's are initialized in two steps, bdi_init() and bdi_register(), but
destroyed in a single step by bdi_destroy() which, for a bdi embedded
in a request_queue, is called during blk_cleanup_queue() which makes
the queue invisible and starts the draining of remaining usages.
A request_queue's user can access the congestion state of the embedded
bdi as long as it holds a reference to the queue. As such, it may
access the congested state of a queue which finished
blk_cleanup_queue() but hasn't reached blk_release_queue() yet.
Because the congested state was embedded in backing_dev_info which in
turn is embedded in request_queue, accessing the congested state after
bdi_destroy() was called was fine. The bdi was destroyed but the
memory region for the congested state remained accessible till the
queue got released.
a13f35e871 ("writeback: don't embed root bdi_writeback_congested in
bdi_writeback") changed the situation. Now, the root congested state
which is expected to be pinned while request_queue remains accessible
is separately reference counted and the base ref is put during
bdi_destroy(). This means that the root congested state may go away
prematurely while the queue is between bdi_dstroy() and
blk_cleanup_queue(), which was detected by Andrey's KASAN tests.
The root cause of this problem is that bdi doesn't distinguish the two
steps of destruction, unregistration and release, and now the root
congested state actually requires a separate release step. To fix the
issue, this patch separates out bdi_unregister() and bdi_exit() from
bdi_destroy(). bdi_unregister() is called from blk_cleanup_queue()
and bdi_exit() from blk_release_queue(). bdi_destroy() is now just a
simple wrapper calling the two steps back-to-back.
While at it, the prototype of bdi_destroy() is moved right below
bdi_setup_and_register() so that the counterpart operations are
located together.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: a13f35e871 ("writeback: don't embed root bdi_writeback_congested in bdi_writeback")
Cc: stable@vger.kernel.org # v4.2+
Reported-and-tested-by: Andrey Konovalov <andreyknvl@google.com>
Link: http://lkml.kernel.org/g/CAAeHK+zUJ74Zn17=rOyxacHU18SgCfC6bsYW=6kCY5GXJBwGfQ@mail.gmail.com
Reviewed-by: Jan Kara <jack@suse.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
tags is freed in blk_mq_free_rq_map() and should not be used after that.
The problem doesn't manifest if CONFIG_CPUMASK_OFFSTACK is false because
free_cpumask_var() is nop.
tags->cpumask is allocated in blk_mq_init_tags() so it's natural to
free cpumask in its counter part, blk_mq_free_tags().
Fixes: f26cdc8536 ("blk-mq: Shared tag enhancements")
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Keith Busch <keith.busch@intel.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blk_mq_tag_update_depth() seems to be missing a memory barrier which
might cause the waker to not notice the waiter and fail to send a
wake_up as in the following figure.
blk_mq_tag_update_depth bt_get
------------------------------------------------------------------------
if (waitqueue_active(&bs->wait))
/* The CPU might reorder the test for
the waitqueue up here, before
prior writes complete */
prepare_to_wait(&bs->wait, &wait,
TASK_UNINTERRUPTIBLE);
tag = __bt_get(hctx, bt, last_tag,
tags);
/* Value set in bt_update_count not
visible yet */
bt_update_count(&tags->bitmap_tags, tdepth);
/* blk_mq_tag_wakeup_all(tags, false); */
bt = &tags->bitmap_tags;
wake_index = atomic_read(&bt->wake_index);
...
io_schedule();
------------------------------------------------------------------------
This patch adds the missing memory barrier.
I found this issue when I was looking through the linux source code
for places calling waitqueue_active() before wake_up*(), but without
preceding memory barriers, after sending a patch to fix a similar
issue in drivers/tty/n_tty.c (Details about the original issue can be
found here: https://lkml.org/lkml/2015/9/28/849).
Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
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Merge tag 'v4.3-rc4' into for-4.4/core
Linux 4.3-rc4
Pulling in v4.3-rc4 to avoid conflicts with NVMe fixes that have gone
in since for-4.4/core was based.
And replace the blk_mq_tag_busy_iter with it - the driver use has been
replaced with a new helper a while ago, and internal to the block we
only need the new version.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
blk_mq_complete_request may be a no-op if the request has already
been completed by others means (e.g. a timeout or cancellation), but
currently drivers have to set rq->errors before calling
blk_mq_complete_request, which might leave us with the wrong error value.
Add an error parameter to blk_mq_complete_request so that we can
defer setting rq->errors until we known we won the race to complete the
request.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
CPU hotplug handling for blk-mq (blk_mq_queue_reinit) acquires
all_q_mutex in blk_mq_queue_reinit_notify() and then removes sysfs
entries by blk_mq_sysfs_unregister(). Removing sysfs entry needs to
be blocked until the active reference of the kernfs_node to be zero.
On the other hand, reading blk_mq_hw_sysfs_cpu sysfs entry (e.g.
/sys/block/nullb0/mq/0/cpu_list) acquires all_q_mutex in
blk_mq_hw_sysfs_cpus_show().
If these happen at the same time, a deadlock can happen. Because one
can wait for the active reference to be zero with holding all_q_mutex,
and the other tries to acquire all_q_mutex with holding the active
reference.
The reason that all_q_mutex is acquired in blk_mq_hw_sysfs_cpus_show()
is to avoid reading an imcomplete hctx->cpumask. Since reading sysfs
entry for blk-mq needs to acquire q->sysfs_lock, we can avoid deadlock
and reading an imcomplete hctx->cpumask by protecting q->sysfs_lock
while hctx->cpumask is being updated.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Notifier callbacks for CPU_ONLINE action can be run on the other CPU
than the CPU which was just onlined. So it is possible for the
process running on the just onlined CPU to insert request and run
hw queue before establishing new mapping which is done by
blk_mq_queue_reinit_notify().
This can cause a problem when the CPU has just been onlined first time
since the request queue was initialized. At this time ctx->index_hw
for the CPU, which is the index in hctx->ctxs[] for this ctx, is still
zero before blk_mq_queue_reinit_notify() is called by notifier
callbacks for CPU_ONLINE action.
For example, there is a single hw queue (hctx) and two CPU queues
(ctx0 for CPU0, and ctx1 for CPU1). Now CPU1 is just onlined and
a request is inserted into ctx1->rq_list and set bit0 in pending
bitmap as ctx1->index_hw is still zero.
And then while running hw queue, flush_busy_ctxs() finds bit0 is set
in pending bitmap and tries to retrieve requests in
hctx->ctxs[0]->rq_list. But htx->ctxs[0] is a pointer to ctx0, so the
request in ctx1->rq_list is ignored.
Fix it by ensuring that new mapping is established before onlined cpu
starts running.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
CPU hotplug handling for blk-mq (blk_mq_queue_reinit) accesses
q->mq_usage_counter while freezing all request queues in all_q_list.
On the other hand, q->mq_usage_counter is deinitialized in
blk_mq_free_queue() before deleting the queue from all_q_list.
So if CPU hotplug event occurs in the window, percpu_ref_kill() is
called with q->mq_usage_counter which has already been marked dead,
and it triggers warning. Fix it by deleting the queue from all_q_list
earlier than destroying q->mq_usage_counter.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
CPU hotplug handling for blk-mq (blk_mq_queue_reinit) updates
q->mq_map by blk_mq_update_queue_map() for all request queues in
all_q_list. On the other hand, q->mq_map is released before deleting
the queue from all_q_list.
So if CPU hotplug event occurs in the window, invalid memory access
can happen. Fix it by releasing q->mq_map in blk_mq_release() to make
it happen latter than removal from all_q_list.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Suggested-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
There is a race between cpu hotplug handling and adding/deleting
gendisk for blk-mq, where both are trying to register and unregister
the same sysfs entries.
null_add_dev
--> blk_mq_init_queue
--> blk_mq_init_allocated_queue
--> add to 'all_q_list' (*)
--> add_disk
--> blk_register_queue
--> blk_mq_register_disk (++)
null_del_dev
--> del_gendisk
--> blk_unregister_queue
--> blk_mq_unregister_disk (--)
--> blk_cleanup_queue
--> blk_mq_free_queue
--> del from 'all_q_list' (*)
blk_mq_queue_reinit
--> blk_mq_sysfs_unregister (-)
--> blk_mq_sysfs_register (+)
While the request queue is added to 'all_q_list' (*),
blk_mq_queue_reinit() can be called for the queue anytime by CPU
hotplug callback. But blk_mq_sysfs_unregister (-) and
blk_mq_sysfs_register (+) in blk_mq_queue_reinit must not be called
before blk_mq_register_disk (++) and after blk_mq_unregister_disk (--)
is finished. Because '/sys/block/*/mq/' is not exists.
There has already been BLK_MQ_F_SYSFS_UP flag in hctx->flags which can
be used to track these sysfs stuff, but it is only fixing this issue
partially.
In order to fix it completely, we just need per-queue flag instead of
per-hctx flag with appropriate locking. So this introduces
q->mq_sysfs_init_done which is properly protected with all_q_mutex.
Also, we need to ensure that blk_mq_map_swqueue() is called with
all_q_mutex is held. Since hctx->nr_ctx is reset temporarily and
updated in blk_mq_map_swqueue(), so we should avoid
blk_mq_register_hctx() seeing the temporary hctx->nr_ctx value
in CPU hotplug handling or adding/deleting gendisk .
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
When unmapped hw queue is remapped after CPU topology is changed,
hctx->tags->cpumask has to be set after hctx->tags is setup in
blk_mq_map_swqueue(), otherwise it causes null pointer dereference.
Fixes: f26cdc8536 ("blk-mq: Shared tag enhancements")
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The pages allocated for struct request contain pointers to other slab
allocations (via ops->init_request). Since kmemleak does not track/scan
page allocations, the slab objects will be reported as leaks (false
positives). This patch adds kmemleak callbacks to allow tracking of such
pages.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Bart Van Assche<bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull block updates from Jens Axboe:
"This is a bit bigger than it should be, but I could (did) not want to
send it off last week due to both wanting extra testing, and expecting
a fix for the bounce regression as well. In any case, this contains:
- Fix for the blk-merge.c compilation warning on gcc 5.x from me.
- A set of back/front SG gap merge fixes, from me and from Sagi.
This ensures that we honor SG gapping for integrity payloads as
well.
- Two small fixes for null_blk from Matias, fixing a leak and a
capacity propagation issue.
- A blkcg fix from Tejun, fixing a NULL dereference.
- A fast clone optimization from Ming, fixing a performance
regression since the arbitrarily sized bio's were introduced.
- Also from Ming, a regression fix for bouncing IOs"
* 'for-linus' of git://git.kernel.dk/linux-block:
block: fix bounce_end_io
block: blk-merge: fast-clone bio when splitting rw bios
block: blkg_destroy_all() should clear q->root_blkg and ->root_rl.blkg
block: Copy a user iovec if it includes gaps
block: Refuse adding appending a gapped integrity page to a bio
block: Refuse request/bio merges with gaps in the integrity payload
block: Check for gaps on front and back merges
null_blk: fix wrong capacity when bs is not 512 bytes
null_blk: fix memory leak on cleanup
block: fix bogus compiler warnings in blk-merge.c
cgroup_on_dfl() tests whether the cgroup's root is the default
hierarchy; however, an individual controller is only interested in
whether the controller is attached to the default hierarchy and never
tests a cgroup which doesn't belong to the hierarchy that the
controller is attached to.
This patch replaces cgroup_on_dfl() tests in controllers with faster
static_key based cgroup_subsys_on_dfl(). This leaves cgroup core as
the only user of cgroup_on_dfl() and the function is moved from the
header file to cgroup.c.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Zefan Li <lizefan@huawei.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
When bio bounce is involved, one new bio and its biovecs are
cloned from the comming bio, which can be one fast-cloned bio
from upper layer(such as dm).
So it is obviously wrong to assume the start index of the coming(
original) bio's io vector is zero, which can be any value between
0 and (bi_max_vecs - 1), especially in case of bio split.
This patch fixes Fedora's booting oops on i386, often with the
following kernel log together:
> [ 9.026738] systemd[1]: Switching root.
> [ 9.036467] systemd-journald[149]: Received SIGTERM from PID 1
> (systemd).
> [ 9.082262] BUG: Bad page state in process kworker/u5:1 pfn:372ac
> [ 9.083989] page:f3d32ae0 count:0 mapcount:0 mapping:f2252178
> index:0x16a
> [ 9.085755] flags: 0x40020021(locked|lru|mappedtodisk)
> [ 9.087284] page dumped because: page still charged to cgroup
> [ 9.088772] bad because of flags:
> [ 9.089731] flags: 0x21(locked|lru)
> [ 9.090818] page->mem_cgroup:f2c3e400
Reported-by: Josh Boyer <jwboyer@fedoraproject.org>
Tested-by: Adam Williamson <awilliam@redhat.com>
Cc: Ming Lin <mlin@kernel.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
biovecs has become immutable since v3.13, so it isn't necessary
to allocate biovecs for the new cloned bios, then we can save
one extra biovecs allocation/copy, and the allocation is often
not fixed-length and a bit more expensive.
For example, if the 'max_sectors_kb' of null blk's queue is set
as 16(32 sectors) via sysfs just for making more splits, this patch
can increase throught about ~70% in the sequential read test over
null_blk(direct io, bs: 1M).
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Ming Lin <ming.l@ssi.samsung.com>
Cc: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
This fixes a performance regression introduced by commit 54efd50bfd,
and allows us to take full advantage of the fact that we have immutable
bio_vecs. Hand applied, as it rejected violently with commit
5014c311ba.
Signed-off-by: Jens Axboe <axboe@fb.com>
While making the root blkg unconditional, ec13b1d6f0 ("blkcg: always
create the blkcg_gq for the root blkcg") removed the part which clears
q->root_blkg and ->root_rl.blkg during q exit. This leaves the two
pointers dangling after blkg_destroy_all(). blk-throttle exit path
performs blkg traversals and dereferences ->root_blkg and can lead to
the following oops.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000558
IP: [<ffffffff81389746>] __blkg_lookup+0x26/0x70
...
task: ffff88001b4e2580 ti: ffff88001ac0c000 task.ti: ffff88001ac0c000
RIP: 0010:[<ffffffff81389746>] [<ffffffff81389746>] __blkg_lookup+0x26/0x70
...
Call Trace:
[<ffffffff8138d14a>] blk_throtl_drain+0x5a/0x110
[<ffffffff8138a108>] blkcg_drain_queue+0x18/0x20
[<ffffffff81369a70>] __blk_drain_queue+0xc0/0x170
[<ffffffff8136a101>] blk_queue_bypass_start+0x61/0x80
[<ffffffff81388c59>] blkcg_deactivate_policy+0x39/0x100
[<ffffffff8138d328>] blk_throtl_exit+0x38/0x50
[<ffffffff8138a14e>] blkcg_exit_queue+0x3e/0x50
[<ffffffff8137016e>] blk_release_queue+0x1e/0xc0
...
While the bug is a straigh-forward use-after-free bug, it is tricky to
reproduce because blkg release is RCU protected and the rest of exit
path usually finishes before RCU grace period.
This patch fixes the bug by updating blkg_destro_all() to clear
q->root_blkg and ->root_rl.blkg.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Richard W.M. Jones" <rjones@redhat.com>
Reported-by: Josh Boyer <jwboyer@fedoraproject.org>
Link: http://lkml.kernel.org/g/CA+5PVA5rzQ0s4723n5rHBcxQa9t0cW8BPPBekr_9aMRoWt2aYg@mail.gmail.com
Fixes: ec13b1d6f0 ("blkcg: always create the blkcg_gq for the root blkcg")
Cc: stable@vger.kernel.org # v4.2+
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
For drivers that don't support gaps in the SG lists handed to
them we must bounce (copy the user buffers) and pass a bio that
does not include gaps. This doesn't matter for any current user,
but will help to allow iser which can't handle gaps to use the
block virtual boundary instead of using driver-local bounce
buffering when handling SG_IO commands.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This is only theoretical at the moment given that the only
subsystems that generate integrity payloads are the block layer
itself and the scsi target (which generate well aligned integrity
payloads). But when we will expose integrity meta-data to user-space,
we'll need to refuse appending a page with a gap (if the queue
virtual boundary is set).
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If a driver sets the block queue virtual boundary mask, it means that
it cannot handle gaps so we must not allow those in the integrity
payload as well.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Fixed up by me to have duplicate integrity merge functions, depending
on whether block integrity is enabled or not. Fixes a compilations
issue with CONFIG_BLK_DEV_INTEGRITY unset.
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull blk-cg updates from Jens Axboe:
"A bit later in the cycle, but this has been in the block tree for a a
while. This is basically four patchsets from Tejun, that improve our
buffered cgroup writeback. It was dependent on the other cgroup
changes, but they went in earlier in this cycle.
Series 1 is set of 5 patches that has cgroup writeback updates:
- bdi_writeback iteration fix which could lead to some wb's being
skipped or repeated during e.g. sync under memory pressure.
- Simplification of wb work wait mechanism.
- Writeback tracepoints updated to report cgroup.
Series 2 is is a set of updates for the CFQ cgroup writeback handling:
cfq has always charged all async IOs to the root cgroup. It didn't
have much choice as writeback didn't know about cgroups and there
was no way to tell who to blame for a given writeback IO.
writeback finally grew support for cgroups and now tags each
writeback IO with the appropriate cgroup to charge it against.
This patchset updates cfq so that it follows the blkcg each bio is
tagged with. Async cfq_queues are now shared across cfq_group,
which is per-cgroup, instead of per-request_queue cfq_data. This
makes all IOs follow the weight based IO resource distribution
implemented by cfq.
- Switched from GFP_ATOMIC to GFP_NOWAIT as suggested by Jeff.
- Other misc review points addressed, acks added and rebased.
Series 3 is the blkcg policy cleanup patches:
This patchset contains assorted cleanups for blkcg_policy methods
and blk[c]g_policy_data handling.
- alloc/free added for blkg_policy_data. exit dropped.
- alloc/free added for blkcg_policy_data.
- blk-throttle's async percpu allocation is replaced with direct
allocation.
- all methods now take blk[c]g_policy_data instead of blkcg_gq or
blkcg.
And finally, series 4 is a set of patches cleaning up the blkcg stats
handling:
blkcg's stats have always been somwhat of a mess. This patchset
tries to improve the situation a bit.
- The following patches added to consolidate blkcg entry point and
blkg creation. This is in itself is an improvement and helps
colllecting common stats on bio issue.
- per-blkg stats now accounted on bio issue rather than request
completion so that bio based and request based drivers can behave
the same way. The issue was spotted by Vivek.
- cfq-iosched implements custom recursive stats and blk-throttle
implements custom per-cpu stats. This patchset make blkcg core
support both by default.
- cfq-iosched and blk-throttle keep track of the same stats
multiple times. Unify them"
* 'for-4.3/blkcg' of git://git.kernel.dk/linux-block: (45 commits)
blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy
blkcg: s/CFQ_WEIGHT_*/CFQ_WEIGHT_LEGACY_*/
blkcg: implement interface for the unified hierarchy
blkcg: misc preparations for unified hierarchy interface
blkcg: separate out tg_conf_updated() from tg_set_conf()
blkcg: move body parsing from blkg_conf_prep() to its callers
blkcg: mark existing cftypes as legacy
blkcg: rename subsystem name from blkio to io
blkcg: refine error codes returned during blkcg configuration
blkcg: remove unnecessary NULL checks from __cfqg_set_weight_device()
blkcg: reduce stack usage of blkg_rwstat_recursive_sum()
blkcg: remove cfqg_stats->sectors
blkcg: move io_service_bytes and io_serviced stats into blkcg_gq
blkcg: make blkg_[rw]stat_recursive_sum() to be able to index into blkcg_gq
blkcg: make blkcg_[rw]stat per-cpu
blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it
blkcg: consolidate blkg creation in blkcg_bio_issue_check()
blk-throttle: improve queue bypass handling
blkcg: move root blkg lookup optimization from throtl_lookup_tg() to __blkg_lookup()
blkcg: inline [__]blkg_lookup()
...
Pull ext3 removal, quota & udf fixes from Jan Kara:
"The biggest change in the pull is the removal of ext3 filesystem
driver (~28k lines removed). Ext4 driver is a full featured
replacement these days and both RH and SUSE use it for several years
without issues. Also there are some workarounds in VM & block layer
mainly for ext3 which we could eventually get rid of.
Other larger change is addition of proper error handling for
dquot_initialize(). The rest is small fixes and cleanups"
[ I wasn't convinced about the ext3 removal and worried about things
falling through the cracks for legacy users, but ext4 maintainers
piped up and were all unanimously in favor of removal, and maintaining
all legacy ext3 support inside ext4. - Linus ]
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
udf: Don't modify filesystem for read-only mounts
quota: remove an unneeded condition
ext4: memory leak on error in ext4_symlink()
mm/Kconfig: NEED_BOUNCE_POOL: clean-up condition
ext4: Improve ext4 Kconfig test
block: Remove forced page bouncing under IO
fs: Remove ext3 filesystem driver
doc: Update doc about journalling layer
jfs: Handle error from dquot_initialize()
reiserfs: Handle error from dquot_initialize()
ocfs2: Handle error from dquot_initialize()
ext4: Handle error from dquot_initialize()
ext2: Handle error from dquot_initalize()
quota: Propagate error from ->acquire_dquot()
We are checking for gaps to previous bio_vec, which can
only detect back merges gaps. Moreover, at the point where
we check for a gap, we don't know if we will attempt a back
or a front merge. Thus, check for gap to prev in a back merge
attempt and check for a gap to next in a front merge attempt.
Signed-off-by: Jens Axboe <axboe@fb.com>
[sagig: Minor rename change]
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
The compiler can't figure out that bvprv is initialized whenever 'prev'
is set to 1 as well. Use a pointer to bvprv instead, setting it to NULL
initially, and get rid of the 'prev' tracking. This dumbs it down
enough that gcc is happy.
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull SG updates from Jens Axboe:
"This contains a set of scatter-gather related changes/fixes for 4.3:
- Add support for limited chaining of sg tables even for
architectures that do not set ARCH_HAS_SG_CHAIN. From Christoph.
- Add sg chain support to target_rd. From Christoph.
- Fixup open coded sg->page_link in crypto/omap-sham. From
Christoph.
- Fixup open coded crypto ->page_link manipulation. From Dan.
- Also from Dan, automated fixup of manual sg_unmark_end()
manipulations.
- Also from Dan, automated fixup of open coded sg_phys()
implementations.
- From Robert Jarzmik, addition of an sg table splitting helper that
drivers can use"
* 'for-4.3/sg' of git://git.kernel.dk/linux-block:
lib: scatterlist: add sg splitting function
scatterlist: use sg_phys()
crypto/omap-sham: remove an open coded access to ->page_link
scatterlist: remove open coded sg_unmark_end instances
crypto: replace scatterwalk_sg_chain with sg_chain
target/rd: always chain S/G list
scatterlist: allow limited chaining without ARCH_HAS_SG_CHAIN
Pull core block updates from Jens Axboe:
"This first core part of the block IO changes contains:
- Cleanup of the bio IO error signaling from Christoph. We used to
rely on the uptodate bit and passing around of an error, now we
store the error in the bio itself.
- Improvement of the above from myself, by shrinking the bio size
down again to fit in two cachelines on x86-64.
- Revert of the max_hw_sectors cap removal from a revision again,
from Jeff Moyer. This caused performance regressions in various
tests. Reinstate the limit, bump it to a more reasonable size
instead.
- Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me.
Most devices have huge trim limits, which can cause nasty latencies
when deleting files. Enable the admin to configure the size down.
We will look into having a more sane default instead of UINT_MAX
sectors.
- Improvement of the SGP gaps logic from Keith Busch.
- Enable the block core to handle arbitrarily sized bios, which
enables a nice simplification of bio_add_page() (which is an IO hot
path). From Kent.
- Improvements to the partition io stats accounting, making it
faster. From Ming Lei.
- Also from Ming Lei, a basic fixup for overflow of the sysfs pending
file in blk-mq, as well as a fix for a blk-mq timeout race
condition.
- Ming Lin has been carrying Kents above mentioned patches forward
for a while, and testing them. Ming also did a few fixes around
that.
- Sasha Levin found and fixed a use-after-free problem introduced by
the bio->bi_error changes from Christoph.
- Small blk cgroup cleanup from Viresh Kumar"
* 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits)
blk: Fix bio_io_vec index when checking bvec gaps
block: Replace SG_GAPS with new queue limits mask
block: bump BLK_DEF_MAX_SECTORS to 2560
Revert "block: remove artifical max_hw_sectors cap"
blk-mq: fix race between timeout and freeing request
blk-mq: fix buffer overflow when reading sysfs file of 'pending'
Documentation: update notes in biovecs about arbitrarily sized bios
block: remove bio_get_nr_vecs()
fs: use helper bio_add_page() instead of open coding on bi_io_vec
block: kill merge_bvec_fn() completely
md/raid5: get rid of bio_fits_rdev()
md/raid5: split bio for chunk_aligned_read
block: remove split code in blkdev_issue_{discard,write_same}
btrfs: remove bio splitting and merge_bvec_fn() calls
bcache: remove driver private bio splitting code
block: simplify bio_add_page()
block: make generic_make_request handle arbitrarily sized bios
blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL)
block: don't access bio->bi_error after bio_put()
block: shrink struct bio down to 2 cache lines again
...
The SG_GAPS queue flag caused checks for bio vector alignment against
PAGE_SIZE, but the device may have different constraints. This patch
adds a queue limits so a driver with such constraints can set to allow
requests that would have been unnecessarily split. The new gaps check
takes the request_queue as a parameter to simplify the logic around
invoking this function.
This new limit makes the queue flag redundant, so removing it and
all usage. Device-mappers will inherit the correct settings through
blk_stack_limits().
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
cgroup is trying to make interface consistent across different
controllers. For weight based resource control, the knob should have
the range [1, 10000] and default to 100. This patch updates
cfq-iosched so that the weight range conforms. The internal
calculations have enough range and the widening of the weight range
shouldn't cause any problem.
* blkcg_policy->cpd_bind_fn() is added. If present, this is invoked
when blkcg is attached to a hierarchy.
* cfq_cpd_init() is updated to use the new default value on the
unified hierarchy.
* cfq_cpd_bind() callback is implemented to clear per-blkg configs and
apply the default config matching the hierarchy type.
* cfqd->root_group->[leaf_]weight initialization in cfq_init_queue()
is moved into !CONFIG_CFQ_GROUP_IOSCHED block. cfq_cpd_bind() is
now responsible for initializing the initial weights when blkcg is
enabled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkcg is gonna switch to cgroup common weight range as defined by
CGROUP_WEIGHT_* on the unified hierarchy. In preparation, rename
CFQ_WEIGHT_* constants to CFQ_WEIGHT_LEGACY_*.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkcg interface grew to be the biggest of all controllers and
unfortunately most inconsistent too. The interface files are
inconsistent with a number of cloes duplicates. Some files have
recursive variants while others don't. There's distinction between
normal and leaf weights which isn't intuitive and there are a lot of
stat knobs which don't make much sense outside of debugging and expose
too much implementation details to userland.
In the unified hierarchy, everything is always hierarchical and
internal nodes can't have tasks rendering the two structural issues
twisting the current interface. The interface has to be updated in a
significant anyway and this is a good chance to revamp it as a whole.
This patch implements blkcg interface for the unified hierarchy.
* (from a previous patch) blkcg is identified by "io" instead of
"blkio" on the unified hierarchy. Given that the whole interface is
updated anyway, the rename shouldn't carry noticeable conversion
overhead.
* The original interface consisted of 27 files is replaced with the
following three files.
blkio.stat : per-blkcg stats
blkio.weight : per-cgroup and per-cgroup-queue weight settings
blkio.max : per-cgroup-queue bps and iops max limits
Documentation/cgroups/unified-hierarchy.txt updated accordingly.
v2: blkcg_policy->dfl_cftypes wasn't removed on
blkcg_policy_unregister() corrupting the cftypes list. Fixed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
tg_set_conf() is largely consisted of parsing and setting the new
config and the follow-up application and propagation. This patch
separates out the latter part into tg_conf_updated(). This will be
used to implement interface for the unified hierarchy.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, blkg_conf_prep() expects input to be of the following form
MAJ:MIN NUM
and reads the NUM part into blkg_conf_ctx->v. This is quite
restrictive and gets in the way in implementing blkcg interface for
the unified hierarchy. This patch updates blkg_conf_prep() so that it
expects
MAJ:MIN BODY_STR
where BODY_STR is an arbitrary string. blkg_conf_ctx->v is replaced
with ->body which is a char pointer pointing to the start of BODY_STR.
Parsing of the body is moved to blkg_conf_prep()'s callers.
To allow using, for example, strsep() on blkg_conf_ctx->val, it is a
non-const pointer and to accommodate that const is dropped from @input
too.
This doesn't cause any behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkio interface has become messy over time and is currently the
largest. In addition to the inconsistent naming scheme, it has
multiple stat files which report more or less the same thing, a number
of debug stat files which expose internal details which shouldn't have
been part of the public interface in the first place, recursive and
non-recursive stats and leaf and non-leaf knobs.
Both recursive vs. non-recursive and leaf vs. non-leaf distinctions
don't make any sense on the unified hierarchy as only leaf cgroups can
contain processes. cgroups is going through a major interface
revision with the unified hierarchy involving significant fundamental
usage changes and given that a significant portion of the interface
doesn't make sense anymore, it's a good time to reorganize the
interface.
As the first step, this patch renames the external visible subsystem
name from "blkio" to "io". This is more concise, matches the other
two major subsystem names, "cpu" and "memory", and better suited as
blkcg will be involved in anything writeback related too whether an
actual block device is involved or not.
As the subsystem legacy_name is set to "blkio", the only userland
visible change outside the unified hierarchy is that blkcg is reported
as "io" instead of "blkio" in the subsystem initialized message during
boot. On the unified hierarchy, blkcg now appears as "io".
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
blkcg currently returns -EINVAL for most errors which can be pretty
confusing given that the failure modes are quite varied. Update the
error returns so that
* -EINVAL only for syntactic errors.
* -ERANGE if the value is out of range.
* -ENODEV if the target device can't be found.
* -EOPNOTSUPP if the policy is not enabled on the target device.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkg_to_cfqg() and blkcg_to_cfqgd() on a valid blkg with the policy
enabled are guaranteed to return non-NULL and the counterpart in
blk-throttle doesn't have these checks either. Remove the spurious
NULL checks.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
The recent percpu conversion of blkg_rwstat triggered the following
warning in certain configurations.
block/blk-cgroup.c:654:1: warning: the frame size of 1360 bytes is larger than 1024 bytes
This is because blkg_rwstat now contains four percpu_counter which can
be pretty big depending on debug options although it shouldn't be a
problem in production configs. This patch removes one of the two
local blkg_rwstat variables used by blkg_rwstat_recursive_sum() to
reduce stack usage.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Link: http://article.gmane.org/gmane.linux.kernel.cgroups/13835
Signed-off-by: Jens Axboe <axboe@fb.com>
cfq_stats->sectors is a blkg_stat which keeps track of the total
number of sectors serviced; however, this can be trivially calculated
from blkcg_gq->stat_bytes. The only thing necessary is adding up
READs and WRITEs and then dividing by sector size.
Remove cfqg_stats->sectors and make cfq print "sectors" and
"sectors_recursive" from stat_bytes.
While this is a bit more code, it removes duplicate stat allocations
and updates and ensures that the reported stats stay in tune with each
other.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, both cfq-iosched and blk-throttle keep track of
io_service_bytes and io_serviced stats. While keeping track of them
separately may be useful during development, it doesn't make much
sense otherwise. Also, blk-throttle was counting bio's as IOs while
cfq-iosched request's, which is more confusing than informative.
This patch adds ->stat_bytes and ->stat_ios to blkg (blkcg_gq),
removes the counterparts from cfq-iosched and blk-throttle and let
them print from the common blkg counters. The common counters are
incremented during bio issue in blkcg_bio_issue_check().
The outputs are still filtered by whether the policy has
blkg_policy_data on a given blkg, so cfq's output won't show up if it
has never been used for a given blkg. The only times when the outputs
would differ significantly are when policies are attached on the fly
or elevators are switched back and forth. Those are quite exceptional
operations and I don't think they warrant keeping separate counters.
v3: Update blkio-controller.txt accordingly.
v2: Account IOs during bio issues instead of request completions so
that bio-based drivers can be handled the same way.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, blkg_[rw]stat_recursive_sum() assume that the target
counter is located in pd (blkg_policy_data); however, some counters
are planned to be moved to blkg (blkcg_gq).
This patch updates blkg_[rw]stat_recursive_sum() to take blkg and
blkg_policy pointers instead of pd. If policy is NULL, it indexes
into blkg. If non-NULL, into the blkg's pd of the policy.
The existing usages are updated to maintain the current behaviors.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkcg_[rw]stat are used as stat counters for blkcg policies. It isn't
per-cpu by itself and blk-throttle makes it per-cpu by wrapping around
it. This patch makes blkcg_[rw]stat per-cpu and drop the ad-hoc
per-cpu wrapping in blk-throttle.
* blkg_[rw]stat->cnt is replaced with cpu_cnt which is struct
percpu_counter. This makes syncp unnecessary as remote accesses are
handled by percpu_counter itself.
* blkg_[rw]stat_init() can now fail due to percpu allocation failure
and thus are updated to return int.
* percpu_counters need explicit freeing. blkg_[rw]stat_exit() added.
* As blkg_rwstat->cpu_cnt[] can't be read directly anymore, reading
and summing results are stored in ->aux_cnt[] instead.
* Custom per-cpu stat implementation in blk-throttle is removed.
This makes all blkcg stat counters per-cpu without complicating policy
implmentations.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
cgroup stats are local to each cgroup and doesn't propagate to
ancestors by default. When recursive stats are necessary, the sum is
calculated over all the descendants. This initially was for backward
compatibility to support both group-local and recursive stats but this
mode of operation makes general sense as stat update is much hotter
thafn reporting those stats.
This however ends up losing recursive stats when a child is removed.
To work around this, cfq-iosched adds its stats to its parent
cfq_group->dead_stats which is summed up together when calculating
recursive stats.
It's planned that the core stats will be moved to blkcg_gq, so we want
to move the mechanism for keeping track of the stats of dead children
from cfq to blkcg core. This patch adds blkg_[rw]stat->aux_cnt which
are atomic64_t's keeping track of auxiliary counts which are excluded
when reading local counts but included for recursive.
blkg_[rw]stat_merge() which were used by cfq to implement dead_stats
are replaced by blkg_[rw]stat_add_aux(), and cfq now forwards stats of
a dead cgroup to the aux counts of parent->stats instead of separate
->dead_stats.
This will also help making blkg_[rw]stats per-cpu.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkg (blkcg_gq) currently is created by blkcg policies invoking
blkg_lookup_create() which ends up repeating about the same code in
different policies. Theoretically, this can avoid the overhead of
looking and/or creating blkg's if blkcg is enabled but no policy is in
use; however, the cost of blkg lookup / creation is very low
especially if only the root blkcg is in use which is highly likely if
no blkcg policy is in active use - it boils down to a single very
predictable conditional and surrounding RCU protection.
This patch consolidates blkg creation to a new function
blkcg_bio_issue_check() which is called during bio issue from
generic_make_request_checks(). blkcg_bio_issue_check() is now the
only function which tries to create missing blkg's. The subsequent
policy and request_list operations just perform blkg_lookup() and if
missing falls back to the root.
* blk_get_rl() no longer tries to create blkg. It uses blkg_lookup()
instead of blkg_lookup_create().
* blk_throtl_bio() is now called from blkcg_bio_issue_check() with rcu
read locked and blkg already looked up. Both throtl_lookup_tg() and
throtl_lookup_create_tg() are dropped.
* cfq is similarly updated. cfq_lookup_create_cfqg() is replaced with
cfq_lookup_cfqg()which uses blkg_lookup().
This consolidates blkg handling and avoids unnecessary blkg creation
retries under memory pressure. In addition, this provides a common
bio entry point into blkcg where things like common accounting can be
performed.
v2: Build fixes for !CONFIG_CFQ_GROUP_IOSCHED and
!CONFIG_BLK_DEV_THROTTLING.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If a queue is bypassing, all blkcg policies should become noops but
blk-throttle wasn't. It only became noop if the queue was dying.
While this wouldn't lead to an oops as falling back to the root blkg
is safe in this case, this can be a bit surprising - a bypassing queue
could still be applying throttle limits.
Fix it by removing blk_queue_dying() test in throtl_lookup_create_tg()
and testing blk_queue_bypass() in blk_throtl_bio() and bypassing
before doing anything else.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, both throttle and cfq policies implement their own root
blkg (blkcg_gq) lookup fast path. This patch moves root blkg
optimization from throtl_lookup_tg() to __blkg_lookup(). cfq-iosched
currently doesn't use blkg_lookup() but will be converted and drop the
optimization too.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkg_lookup() checks whether the target queue is bypassing and, if
not, calls __blkg_lookup() which first checks the lookup hint and then
performs radix tree walk. The operations upto hint checking are
trivial and there are many users of this function. This patch inlines
blkg_lookup() and the fast path part of __blkg_lookup(). The radix
tree lookup and hint update are now in blkg_lookup_slowpath().
This will help consolidating blkg handling by easing moving root blkcg
short-circuit to inlined lookup fast path.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Each active policy has a cpd (blkcg_policy_data) on each blkcg. The
cpd's were allocated by blkcg core and each policy could request to
allocate extra space at the end by setting blkcg_policy->cpd_size
larger than the size of cpd.
This is a bit unusual but blkg (blkcg_gq) policy data used to be
handled this way too so it made sense to be consistent; however, blkg
policy data switched to alloc/free callbacks.
This patch makes similar changes to cpd handling.
blkcg_policy->cpd_alloc/free_fn() are added to replace ->cpd_size. As
cpd allocation is now done from policy side, it can simply allocate a
larger area which embeds cpd at the beginning.
As ->cpd_alloc_fn() may be able to perform all necessary
initializations, this patch makes ->cpd_init_fn() optional.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
* Rename blkcg->pd[] to blkcg->cpd[] so that cpd is consistently used
for blkcg_policy_data.
* Make blkcg_policy->cpd_init_fn() take blkcg_policy_data instead of
blkcg. This makes it consistent with blkg_policy_data methods and
to-be-added cpd alloc/free methods.
* blkcg_policy_data->blkcg and cpd_to_blkcg() added so that
cpd_init_fn() can determine the associated blkcg from
blkcg_policy_data.
v2: blkcg_policy_data->blkcg initializations were missing. Added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The newly added ->pd_alloc_fn() and ->pd_free_fn() deal with pd
(blkg_policy_data) while the older ones use blkg (blkcg_gq). As using
blkg doesn't make sense for ->pd_alloc_fn() and after allocation pd
can always be mapped to blkg and given that these are policy-specific
methods, it makes sense to converge on pd.
This patch makes all methods deal with pd instead of blkg. Most
conversions are trivial. In blk-cgroup.c, a couple method invocation
sites now test whether pd exists instead of policy state for
consistency. This shouldn't cause any behavioral differences.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
With the recent addition of alloc and free methods, things became
messier. This patch reorganizes them according to the followings.
* ->pd_alloc_fn()
Responsible for allocation and static initializations - the ones
which can be done independent of where the pd might be attached.
* ->pd_init_fn()
Initializations which require the knowledge of where the pd is
attached.
* ->pd_free_fn()
The counter part of pd_alloc_fn(). Static de-init and freeing.
This leaves ->pd_exit_fn() without any users. Removed.
While at it, collapse an one liner function throtl_pd_exit(), which
has only one user, into its user.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Because percpu allocator couldn't do non-blocking allocations,
blk-throttle was forced to implement an ad-hoc asynchronous allocation
mechanism for its percpu stats for cases where blkg's (blkcg_gq's) are
allocated from an IO path without sleepable context.
Now that percpu allocator can handle gfp_mask and blkg_policy_data
alloc / free are handled by policy methods, the ad-hoc asynchronous
allocation mechanism can be replaced with direct allocation from
tg_stats_alloc_fn(). Rit it out.
This ensures that an active throtl_grp always has valid non-NULL
->stats_cpu. Remove checks on it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
A blkg (blkcg_gq) represents the relationship between a cgroup and
request_queue. Each active policy has a pd (blkg_policy_data) on each
blkg. The pd's were allocated by blkcg core and each policy could
request to allocate extra space at the end by setting
blkcg_policy->pd_size larger than the size of pd.
This is a bit unusual but was done this way mostly to simplify error
handling and all the existing use cases could be handled this way;
however, this is becoming too restrictive now that percpu memory can
be allocated without blocking.
This introduces two new mandatory blkcg_policy methods - pd_alloc_fn()
and pd_free_fn() - which are used to allocate and release pd for a
given policy. As pd allocation is now done from policy side, it can
simply allocate a larger area which embeds pd at the beginning. This
change makes ->pd_size pointless. Removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkg_create() allows NULL ->pd_init_fn() but blkcg_activate_policy()
doesn't. As both in-kernel policies implement ->pd_init_fn, it
currently doesn't break anything. Update blkcg_activate_policy() so
that its behavior is consistent with blkg_create().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
When a policy gets activated, it needs to allocate and install its
policy data on all existing blkg's (blkcg_gq's). Because blkg
iteration is protected by a spinlock, it currently counts the total
number of blkg's in the system, allocates the matching number of
policy data on a list and installs them during a single iteration.
This can be simplified by using speculative GFP_NOWAIT allocations
while iterating and falling back to a preallocated policy data on
failure. If the preallocated one has already been consumed, it
releases the lock, preallocate with GFP_KERNEL and then restarts the
iteration. This can be a bit more expensive than before but policy
activation is a very cold path and shouldn't matter.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkcg_css_alloc() bypasses policy data allocation and blkcg_css_free()
bypasses policy data and blkcg freeing for blkcg_root. There's no
reason to to treat policy data any differently for blkcg_root. If the
root css gets allocated after policies are registered, policy
registration path will add policy data; otherwise, the alloc path
will. The free path isn't never invoked for root csses.
This patch removes the unnecessary special handling of blkcg_root from
css_alloc/free paths.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
When blkcg_init_queue() fails midway after creating a new blkg, it
performs kfree() directly; however, this doesn't free the policy data
areas. Make it use blkg_free() instead. In turn, blkg_free() is
updated to handle root request_list special case.
While this fixes a possible memory leak, it's on an unlikely failure
path of an already cold path and the size leaked per occurrence is
miniscule too. I don't think it needs to be tagged for -stable.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Up until now, all async IOs were queued to async queues which are
shared across the whole request_queue, which means that blkcg resource
control is completely void on async IOs including all writeback IOs.
It was done this way because writeback didn't support writeback and
there was no way of telling which writeback IO belonged to which
cgroup; however, writeback recently became cgroup aware and writeback
bio's are sent down properly tagged with the blkcg's to charge them
against.
This patch makes async cfq_queues per-cfq_cgroup instead of
per-cfq_data so that each async IO is charged to the blkcg that it was
tagged for instead of unconditionally attributing it to root.
* cfq_data->async_cfqq and ->async_idle_cfqq are moved to cfq_group
and alloc / destroy paths are updated accordingly.
* cfq_link_cfqq_cfqg() no longer overrides @cfqg to root for async
queues.
* check_blkcg_changed() now also invalidates async queues as they no
longer stay the same across cgroups.
After this patch, cfq's proportional IO control through blkio.weight
works correctly when cgroup writeback is in use.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
cfq_find_alloc_queue() checks whether a queue actually needs to be
allocated, which is unnecessary as its sole caller, cfq_get_queue(),
only calls it if so. Also, the oom queue fallback logic is scattered
between cfq_get_queue() and cfq_find_alloc_queue(). There really
isn't much going on in the latter and things can be made simpler by
folding it into cfq_get_queue().
This patch collapses cfq_find_alloc_queue() into cfq_get_queue(). The
change is fairly straight-forward with one exception - async_cfqq is
now initialized to NULL and the "!is_sync" test in the last if
conditional is replaced with "async_cfqq" test. This is because gcc
(5.1.1) gets confused for some reason and warns that async_cfqq may be
used uninitialized otherwise. Oh well, the code isn't necessarily
worse this way.
This patch doesn't cause any functional difference.
v2: Updated to reflect GFP_ATOMIC -> GPF_NOWAIT.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This is necessary for making async cfq_cgroups per-cfq_group instead
of per-cfq_data. While this change makes cfq_get_queue() perform RCU
locking and look up cfq_group even when it reuses async queue, the
extra overhead is extremely unlikely to be noticeable given that this
is already sitting behind cic->cfqq[] cache and the overall cost of
cfq operation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Even when allocations fail, cfq_find_alloc_queue() always returns a
valid cfq_queue by falling back to the oom cfq_queue. As such, there
isn't much point in taking @gfp_mask and trying "harder" if __GFP_WAIT
is set. GFP_NOWAIT allocations don't fail often and even when they do
the degraded behavior is acceptable and temporary.
After all, the only reason get_request(), which ultimately determines
the gfp_mask, cares about __GFP_WAIT is to guarantee request
allocation, assuming IO forward progress, for callers which are
willing to wait. There's no reason for cfq_find_alloc_queue() to
behave differently on __GFP_WAIT when it already has a fallback
mechanism.
Remove @gfp_mask from cfq_find_alloc_queue() and propagate the changes
to its callers. This simplifies the function quite a bit and will
help making async queues per-cfq_group.
v2: Updated to reflect GFP_ATOMIC -> GPF_NOWAIT.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkcg performs several allocations to track IOs per cgroup and enforce
resource control. Most of these allocations are performed lazily on
demand in the IO path and thus can't involve reclaim path. Currently,
these allocations use GFP_ATOMIC; however, blkcg can gracefully deal
with occassional failures of these allocations by punting IOs to the
root cgroup and there's no reason to reach into the emergency reserve.
This patch replaces GFP_ATOMIC with GFP_NOWAIT for the following
allocations.
* bdi_writeback_congested and blkcg_gq allocations in blkg_create().
* radix tree node allocations for blkcg->blkg_tree.
* cfq_queue allocation on ioprio changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-and-Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Suggested-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
* Some were accessing cic->cfqq[] directly. Always use cic_to_cfqq()
and cic_set_cfqq().
* check_ioprio_changed() doesn't need to verify cfq_get_queue()'s
return for NULL. It's always non-NULL. Simplify accordingly.
This patch doesn't cause any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If the cfq_queue cached in cfq_io_cq is the oom one, cfq_set_request()
replaces it by invoking cfq_get_queue() again without putting the oom
queue leaking the reference it was holding. While oom queues are not
released through reference counting, they're still reference counted
and this can theoretically lead to the reference count overflowing and
incorrectly invoke the usual release path on it.
Fix it by making cfq_set_request() put the ref it was holding.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Async cfqq's (cfq_queue's) are shared across cfq_data. When
cfq_get_queue() obtains a new queue from cfq_find_alloc_queue(), it
stashes the pointer in cfq_data and reuses it from then on; however,
the function doesn't consider that cfq_find_alloc_queue() may return
the oom_cfqq under memory pressure and installs the returned queue
unconditionally.
If the oom_cfqq is installed as an async cfqq, cfq_set_request() will
continue calling cfq_get_queue() hoping to replace it with a proper
queue; however, cfq_get_queue() will keep returning the cached queue
for the slot - the oom_cfqq.
Fix it by skipping caching if the queue is the oom one.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
cfq_get_queue()'s control flow looks like the following.
async_cfqq = NULL;
cfqq = NULL;
if (!is_sync) {
...
async_cfqq = ...;
cfqq = *async_cfqq;
}
if (!cfqq)
cfqq = ...;
if (!is_sync && !(*async_cfqq))
...;
The only thing the local variable init, the second if, and the
async_cfqq test in the third if achieves is to skip cfqq creation and
installation if *async_cfqq was already non-NULL. This is needlessly
complicated with different tests examining the same condition.
Simplify it to the following.
if (!is_sync) {
...
async_cfqq = ...;
cfqq = *async_cfqq;
if (cfqq)
goto out;
}
cfqq = ...;
if (!is_sync)
...;
out:
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This reverts commit 34b48db66e.
That commit caused performance regressions for streaming I/O
workloads on a number of different storage devices, from
SATA disks to external RAID arrays. It also managed to
trip up some buggy firmware in at least one drive, causing
data corruption.
The next patch will bump the default max_sectors_kb value to
1280, which will accommodate a 10-data-disk stripe write
with chunk size 128k. In the testing I've done using iozone,
fio, and aio-stress, a value of 1280 does not show a big
performance difference from 512. This will hopefully still
help the software RAID setup that Christoph saw the original
performance gains with while still not regressing other
storage configurations.
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
[hch: split from a larger patch by Dan]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This patch consists of 2 libfc fixes causing rare crashes, one iscsi one
causing a potential hang on shutdown, an I/O blocksize issue which caused a
regression and a memory leak in scsi-mq.
Signed-off-by: James Bottomley <JBottomley@Odin.com>
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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"This has two libfc fixes for bugs causing rare crashes, one iscsi fix
for a potential hang on shutdown, and a fix for an I/O blocksize issue
which caused a regression"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
sd: Fix maximum I/O size for BLOCK_PC requests
libfc: Fix fc_fcp_cleanup_each_cmd()
libfc: Fix fc_exch_recv_req() error path
libiscsi: Fix host busy blocking during connection teardown
There may be lots of pending requests so that the buffer of PAGE_SIZE
can't hold them at all.
One typical example is scsi-mq, the queue depth(.can_queue) of
scsi_host and blk-mq is quite big but scsi_device's queue_depth
is a bit small(.cmd_per_lun), then it is quite easy to have lots
of pending requests in hw queue.
This patch fixes the following warning and the related memory
destruction.
[ 359.025101] fill_read_buffer: blk_mq_hw_sysfs_show+0x0/0x7d returned bad count^M
[ 359.055595] irq event stamp: 15537^M
[ 359.055606] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC ^M
[ 359.055614] Dumping ftrace buffer:^M
[ 359.055660] (ftrace buffer empty)^M
[ 359.055672] Modules linked in: nbd ipv6 kvm_intel kvm serio_raw^M
[ 359.055678] CPU: 4 PID: 21631 Comm: stress-ng-sysfs Not tainted 4.2.0-rc5-next-20150805 #434^M
[ 359.055679] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011^M
[ 359.055682] task: ffff8802161cc000 ti: ffff88021b4a8000 task.ti: ffff88021b4a8000^M
[ 359.055693] RIP: 0010:[<ffffffff811541c5>] [<ffffffff811541c5>] __kmalloc+0xe8/0x152^M
Cc: <stable@vger.kernel.org>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
We can always fill up the bio now, no need to estimate the possible
size based on queue parameters.
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[hch: rebased and wrote a changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
As generic_make_request() is now able to handle arbitrarily sized bios,
it's no longer necessary for each individual block driver to define its
own ->merge_bvec_fn() callback. Remove every invocation completely.
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits)
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[dpark: also remove ->merge_bvec_fn() in dm-thin as well as
dm-era-target, and resolve merge conflicts]
Signed-off-by: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The split code in blkdev_issue_{discard,write_same} can go away
now that any driver that cares does the split. We have to make
sure bio size doesn't overflow.
For discard, we set max discard sectors to (1<<31)>>9 to ensure
it doesn't overflow bi_size and hopefully it is of the proper
granularity as long as the granularity is a power of two.
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Since generic_make_request() can now handle arbitrary size bios, all we
have to do is make sure the bvec array doesn't overflow.
__bio_add_page() doesn't need to call ->merge_bvec_fn(), where
we can get rid of unnecessary code paths.
Removing the call to ->merge_bvec_fn() is also fine, as no driver that
implements support for BLOCK_PC commands even has a ->merge_bvec_fn()
method.
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[dpark: rebase and resolve merge conflicts, change a couple of comments,
make bio_add_page() warn once upon a cloned bio.]
Signed-off-by: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The way the block layer is currently written, it goes to great lengths
to avoid having to split bios; upper layer code (such as bio_add_page())
checks what the underlying device can handle and tries to always create
bios that don't need to be split.
But this approach becomes unwieldy and eventually breaks down with
stacked devices and devices with dynamic limits, and it adds a lot of
complexity. If the block layer could split bios as needed, we could
eliminate a lot of complexity elsewhere - particularly in stacked
drivers. Code that creates bios can then create whatever size bios are
convenient, and more importantly stacked drivers don't have to deal with
both their own bio size limitations and the limitations of the
(potentially multiple) devices underneath them. In the future this will
let us delete merge_bvec_fn and a bunch of other code.
We do this by adding calls to blk_queue_split() to the various
make_request functions that need it - a few can already handle arbitrary
size bios. Note that we add the call _after_ any call to
blk_queue_bounce(); this means that blk_queue_split() and
blk_recalc_rq_segments() don't need to be concerned with bouncing
affecting segment merging.
Some make_request_fn() callbacks were simple enough to audit and verify
they don't need blk_queue_split() calls. The skipped ones are:
* nfhd_make_request (arch/m68k/emu/nfblock.c)
* axon_ram_make_request (arch/powerpc/sysdev/axonram.c)
* simdisk_make_request (arch/xtensa/platforms/iss/simdisk.c)
* brd_make_request (ramdisk - drivers/block/brd.c)
* mtip_submit_request (drivers/block/mtip32xx/mtip32xx.c)
* loop_make_request
* null_queue_bio
* bcache's make_request fns
Some others are almost certainly safe to remove now, but will be left
for future patches.
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Jim Paris <jim@jtan.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Acked-by: NeilBrown <neilb@suse.de> (for the 'md/md.c' bits)
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[dpark: skip more mq-based drivers, resolve merge conflicts, etc.]
Signed-off-by: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit bcdb247c6b ("sd: Limit transfer length") clamped the maximum
size of an I/O request to the MAXIMUM TRANSFER LENGTH field in the BLOCK
LIMITS VPD. This had the unfortunate effect of also limiting the maximum
size of non-filesystem requests sent to the device through sg/bsg.
Avoid using blk_queue_max_hw_sectors() and set the max_sectors queue
limit directly.
Also update the comment in blk_limits_max_hw_sectors() to clarify that
max_hw_sectors defines the limit for the I/O controller only.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Brian King <brking@linux.vnet.ibm.com>
Tested-by: Brian King <brking@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Some places use helpers now, others don't. We only have the 'is set'
helper, add helpers for setting and clearing flags too.
It was a bit of a mess of atomic vs non-atomic access. With
BIO_UPTODATE gone, we don't have any risk of concurrent access to the
flags. So relax the restriction and don't make any of them atomic. The
flags that do have serialization issues (reffed and chained), we
already handle those separately.
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently we have two different ways to signal an I/O error on a BIO:
(1) by clearing the BIO_UPTODATE flag
(2) by returning a Linux errno value to the bi_end_io callback
The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario. Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.
So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This fixes a data corruption bug when using discard on top of MD linear,
raid0 and raid10 personalities.
Commit 20d0189b10 "block: Introduce new bio_split()" permits sharing
the bio_vec between the two resulting bios. That is fine for read/write
requests where the bio_vec is immutable. For discards, however, we need
to be able to attach a payload and update the bio_vec so the page can
get mapped to a scatterlist entry. Therefore the bio_vec can not be
shared when splitting discards and we must do a full clone.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Seunguk Shin <seunguk.shin@samsung.com>
Tested-by: Seunguk Shin <seunguk.shin@samsung.com>
Cc: Seunguk Shin <seunguk.shin@samsung.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: <stable@vger.kernel.org> # v3.14+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
bio_associate_blkcg(), bio_associate_current() and wbc_account_io()
are used to implement cgroup writeback support for filesystems and
thus need to be exported. Export them.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jens Axboe <axboe@fb.com>
JBD layer wrote back data buffers without setting PageWriteback bit.
Thus standard mechanism for guaranteeing stable pages under IO did not
work. Since JBD is gone now and there is no other user of the
functionality, just remove it.
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jan Kara <jack@suse.cz>
When a blkcg configuration is targeted to a partition rather than a
whole device, blkg_conf_prep fails with -EINVAL; unfortunately, it
forgets to put the gendisk ref in that case. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Lots of devices support huge discard sizes these days. Depending
on how the device handles them internally, huge discards can
introduce massive latencies (hundreds of msec) on the device side.
We have a sysfs file, discard_max_bytes, that advertises the max
hardware supported discard size. Make this writeable, and split
the settings into a soft and hard limit. This can be set from
'discard_granularity' and up to the hardware limit.
Add a new sysfs file, 'discard_max_hw_bytes', that shows the hw
set limit.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Percpu refcount is the perfect match for partition's case,
and the conversion is quite straight.
With the convertion, one pair of atomic inc/dec can be saved
for accounting block I/O, which is run in hot path of block I/O.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
So the helper can be used in both generic partition
case and part0 case.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
It is reasonable to set default timeout of request as 30 seconds instead of
30000 ticks, which may be 300 seconds if HZ is 100, for example, some arm64
based systems may choose 100 HZ.
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Fixes: c76cbbcf40 ("blk-mq: put blk_queue_rq_timeout together in blk_mq_init_queue()"
Signed-off-by: Jens Axboe <axboe@fb.com>
e48453c386 ("block, cgroup: implement policy-specific per-blkcg
data") updated per-blkcg policy data to be dynamically allocated.
When a policy is registered, its policy data aren't created. Instead,
when the policy is activated on a queue, the policy data are allocated
if there are blkg's (blkcg_gq's) which are attached to a given blkcg.
This is buggy. Consider the following scenario.
1. A blkcg is created. No blkg's attached yet.
2. The policy is registered. No policy data is allocated.
3. The policy is activated on a queue. As the above blkcg doesn't
have any blkg's, it won't allocate the matching blkcg_policy_data.
4. An IO is issued from the blkcg and blkg is created and the blkcg
still doesn't have the matching policy data allocated.
With cfq-iosched, this leads to an oops.
It also doesn't free policy data on policy unregistration assuming
that freeing of all policy data on blkcg destruction should take care
of it; however, this also is incorrect.
1. A blkcg has policy data.
2. The policy gets unregistered but the policy data remains.
3. Another policy gets registered on the same slot.
4. Later, the new policy tries to allocate policy data on the previous
blkcg but the slot is already occupied and gets skipped. The
policy ends up operating on the policy data of the previous policy.
There's no reason to manage blkcg_policy_data lazily. The reason we
do lazy allocation of blkg's is that the number of all possible blkg's
is the product of cgroups and block devices which can reach a
surprising level. blkcg_policy_data is contrained by the number of
cgroups and shouldn't be a problem.
This patch makes blkcg_policy_data to be allocated for all existing
blkcg's on policy registration and freed on unregistration and removes
blkcg_policy_data handling from policy [de]activation paths. This
makes that blkcg_policy_data are created and removed with the policy
they belong to and fixes the above described problems.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: e48453c386 ("block, cgroup: implement policy-specific per-blkcg data")
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Add all_blkcgs list goes through blkcg->all_blkcgs_node and is
protected by blkcg_pol_mutex. This will be used to fix
blkcg_policy_data allocation bug.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
An entry in blkcg_policy[] is stable while there are non-bypassing
in-flight IOs on a request_queue which has the policy activated. This
is why most derefs of blkcg_policy[] don't need explicit locking;
however, blkcg_css_alloc() isn't invoked from IO path and thus doesn't
have this protection and may race policies being added and removed.
Fix it by adding explicit blkcg_pol_mutex protection around
blkcg_policy[] iteration in blkcg_css_alloc().
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: e48453c386 ("block, cgroup: implement policy-specific per-blkcg data")
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blkcg_pol_mutex primarily protects the blkcg_policy array. It also
protects cgroup file type [un]registration during policy addition /
removal. This puts blkcg_pol_mutex outside cgroup internal
synchronization and in turn makes it impossible to grab from blkcg's
cgroup methods as that leads to cyclic dependency.
Another problematic dependency arising from this is through cgroup
interface file deactivation. Removing a cftype requires removing all
files of the type which in turn involves draining all on-going
invocations of the file methods. This means that an interface file
implementation can't grab blkcg_pol_mutex as draining can lead to AA
deadlock.
blkcg_reset_stats() is already in this situation. It currently
trylocks blkcg_pol_mutex and then unwinds and retries the whole
operation on failure, which is cumbersome at best. It has a lengthy
comment explaining how cgroup internal synchronization is involved and
expected to be updated but as explained above this doesn't need cgroup
internal locking to deadlock. It's a self-contained AA deadlock.
The described circular dependencies can be easily broken by moving
cftype [un]registration out of blkcg_pol_mutex and protect them with
an outer mutex. This patch introduces blkcg_pol_register_mutex which
wraps entire policy [un]registration including cftype operations and
shrinks blkcg_pol_mutex critical section. This also makes the trylock
dancing in blkcg_reset_stats() unnecessary. Removed.
This patch is necessary for the following blkcg_policy_data allocation
bug fixes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, per-blkcg data is freed each time a policy is deactivated,
that is also upon scheduler switch. However, when switching from a
scheduler implementing a policy which requires per-blkcg data to
another one, that same policy might be active on other devices, and
therefore those same per-blkcg data could be still in use.
This commit lets per-blkcg data be freed when the blkcg is freed
instead of on policy deactivation.
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Reported-and-tested-by: Michael Kaminsky <kaminsky@cs.cmu.edu>
Fixes: e48453c3 ("block, cgroup: implement policy-specific per-blkcg data")
Signed-off-by: Jens Axboe <axboe@fb.com>
bio_integrity_alloc() and bio_integrity_free() assume that if a bio was
allocated from a bioset that that bioset also had its bio_integrity_pool
allocated using bioset_integrity_create(). This is a very bad
assumption given that bioset_create() and bioset_integrity_create() are
completely disjoint. Not all callers of bioset_create() have been
trained to also call bioset_integrity_create() -- and they may not care
to be.
Fix this by falling back to kmalloc'ing 'struct bio_integrity_payload'
rather than force all bioset consumers to (wastefully) preallocate a
bio_integrity_pool that they very likely won't actually need (given the
niche nature of the current block integrity support).
Otherwise, a NULL pointer "Kernel BUG" with a trace like the following
will be observed (as seen on s390x using zfcp storage) because dm-io
doesn't use bioset_integrity_create() when creating its bioset:
[ 791.643338] Call Trace:
[ 791.643339] ([<00000003df98b848>] 0x3df98b848)
[ 791.643341] [<00000000002c5de8>] bio_integrity_alloc+0x48/0xf8
[ 791.643348] [<00000000002c6486>] bio_integrity_prep+0xae/0x2f0
[ 791.643349] [<0000000000371e38>] blk_queue_bio+0x1c8/0x3d8
[ 791.643355] [<000000000036f8d0>] generic_make_request+0xc0/0x100
[ 791.643357] [<000000000036f9b2>] submit_bio+0xa2/0x198
[ 791.643406] [<000003ff801f9774>] dispatch_io+0x15c/0x3b0 [dm_mod]
[ 791.643419] [<000003ff801f9b3e>] dm_io+0x176/0x2f0 [dm_mod]
[ 791.643423] [<000003ff8074b28a>] do_reads+0x13a/0x1a8 [dm_mirror]
[ 791.643425] [<000003ff8074b43a>] do_mirror+0x142/0x298 [dm_mirror]
[ 791.643428] [<0000000000154fca>] process_one_work+0x18a/0x3f8
[ 791.643432] [<000000000015598a>] worker_thread+0x132/0x3b0
[ 791.643435] [<000000000015d49a>] kthread+0xd2/0xd8
[ 791.643438] [<00000000005bc0ca>] kernel_thread_starter+0x6/0xc
[ 791.643446] [<00000000005bc0c4>] kernel_thread_starter+0x0/0xc
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Whenever blk_fill_sghdr_rq fails, its errno code is ignored and changed to
EFAULT. This can cause very confusing errors:
$ sg_persist -k /dev/sda
persistent reservation in: pass through os error: Bad address
The fix is trivial, just propagate the return value from
blk_fill_sghdr_rq.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
ability to handle partial request completions -- otherwise with the
current SCSI LLDs these changes could lead to silent data corruption.
- Fix two DM version bumps that were missing from the initial 4.2 DM
pull request (enabled userspace lvm2 to know certain changes have been
made).
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Merge tag 'dm-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fixes from Mike Snitzer:
"Apologies for not pressing this request-based DM partial completion
issue further, it was an oversight on my part. We'll have to get it
fixed up properly and revisit for a future release.
- Revert block and DM core changes the removed request-based DM's
ability to handle partial request completions -- otherwise with the
current SCSI LLDs these changes could lead to silent data
corruption.
- Fix two DM version bumps that were missing from the initial 4.2 DM
pull request (enabled userspace lvm2 to know certain changes have
been made)"
* tag 'dm-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm cache policy smq: fix "default" version to be 1.4.0
dm: bump the ioctl version to 4.32.0
Revert "block, dm: don't copy bios for request clones"
Revert "dm: do not allocate any mempools for blk-mq request-based DM"
This reverts commit 5f1b670d0b.
Justification for revert as reported in this dm-devel post:
https://www.redhat.com/archives/dm-devel/2015-June/msg00160.html
this change should not be pushed to mainline yet.
Firstly, Christoph has a newer version of the patch that fixes silent
data corruption problem:
https://www.redhat.com/archives/dm-devel/2015-May/msg00229.html
And the new version still depends on LLDDs to always complete requests
to the end when error happens, while block API doesn't enforce such a
requirement. If the assumption is ever broken, the inconsistency between
request and bio (e.g. rq->__sector and rq->bio) will cause silent data
corruption:
https://www.redhat.com/archives/dm-devel/2015-June/msg00022.html
Reported-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Pull cgroup writeback support from Jens Axboe:
"This is the big pull request for adding cgroup writeback support.
This code has been in development for a long time, and it has been
simmering in for-next for a good chunk of this cycle too. This is one
of those problems that has been talked about for at least half a
decade, finally there's a solution and code to go with it.
Also see last weeks writeup on LWN:
http://lwn.net/Articles/648292/"
* 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits)
writeback, blkio: add documentation for cgroup writeback support
vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB
writeback: do foreign inode detection iff cgroup writeback is enabled
v9fs: fix error handling in v9fs_session_init()
bdi: fix wrong error return value in cgwb_create()
buffer: remove unusued 'ret' variable
writeback: disassociate inodes from dying bdi_writebacks
writeback: implement foreign cgroup inode bdi_writeback switching
writeback: add lockdep annotation to inode_to_wb()
writeback: use unlocked_inode_to_wb transaction in inode_congested()
writeback: implement unlocked_inode_to_wb transaction and use it for stat updates
writeback: implement [locked_]inode_to_wb_and_lock_list()
writeback: implement foreign cgroup inode detection
writeback: make writeback_control track the inode being written back
writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb()
mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use
writeback: implement memcg writeback domain based throttling
writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes
writeback: implement memcg wb_domain
writeback: update wb_over_bg_thresh() to use wb_domain aware operations
...
Pull core block IO update from Jens Axboe:
"Nothing really major in here, mostly a collection of smaller
optimizations and cleanups, mixed with various fixes. In more detail,
this contains:
- Addition of policy specific data to blkcg for block cgroups. From
Arianna Avanzini.
- Various cleanups around command types from Christoph.
- Cleanup of the suspend block I/O path from Christoph.
- Plugging updates from Shaohua and Jeff Moyer, for blk-mq.
- Eliminating atomic inc/dec of both remaining IO count and reference
count in a bio. From me.
- Fixes for SG gap and chunk size support for data-less (discards)
IO, so we can merge these better. From me.
- Small restructuring of blk-mq shared tag support, freeing drivers
from iterating hardware queues. From Keith Busch.
- A few cfq-iosched tweaks, from Tahsin Erdogan and me. Makes the
IOPS mode the default for non-rotational storage"
* 'for-4.2/core' of git://git.kernel.dk/linux-block: (35 commits)
cfq-iosched: fix other locations where blkcg_to_cfqgd() can return NULL
cfq-iosched: fix sysfs oops when attempting to read unconfigured weights
cfq-iosched: move group scheduling functions under ifdef
cfq-iosched: fix the setting of IOPS mode on SSDs
blktrace: Add blktrace.c to BLOCK LAYER in MAINTAINERS file
block, cgroup: implement policy-specific per-blkcg data
block: Make CFQ default to IOPS mode on SSDs
block: add blk_set_queue_dying() to blkdev.h
blk-mq: Shared tag enhancements
block: don't honor chunk sizes for data-less IO
block: only honor SG gap prevention for merges that contain data
block: fix returnvar.cocci warnings
block, dm: don't copy bios for request clones
block: remove management of bi_remaining when restoring original bi_end_io
block: replace trylock with mutex_lock in blkdev_reread_part()
block: export blkdev_reread_part() and __blkdev_reread_part()
suspend: simplify block I/O handling
block: collapse bio bit space
block: remove unused BIO_RW_BLOCK and BIO_EOF flags
block: remove BIO_EOPNOTSUPP
...
Pull scheduler updates from Ingo Molnar:
"The main changes are:
- lockless wakeup support for futexes and IPC message queues
(Davidlohr Bueso, Peter Zijlstra)
- Replace spinlocks with atomics in thread_group_cputimer(), to
improve scalability (Jason Low)
- NUMA balancing improvements (Rik van Riel)
- SCHED_DEADLINE improvements (Wanpeng Li)
- clean up and reorganize preemption helpers (Frederic Weisbecker)
- decouple page fault disabling machinery from the preemption
counter, to improve debuggability and robustness (David
Hildenbrand)
- SCHED_DEADLINE documentation updates (Luca Abeni)
- topology CPU masks cleanups (Bartosz Golaszewski)
- /proc/sched_debug improvements (Srikar Dronamraju)"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
sched/deadline: Remove needless parameter in dl_runtime_exceeded()
sched: Remove superfluous resetting of the p->dl_throttled flag
sched/deadline: Drop duplicate init_sched_dl_class() declaration
sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target
sched/deadline: Make init_sched_dl_class() __init
sched/deadline: Optimize pull_dl_task()
sched/preempt: Add static_key() to preempt_notifiers
sched/preempt: Fix preempt notifiers documentation about hlist_del() within unsafe iteration
sched/stop_machine: Fix deadlock between multiple stop_two_cpus()
sched/debug: Add sum_sleep_runtime to /proc/<pid>/sched
sched/debug: Replace vruntime with wait_sum in /proc/sched_debug
sched/debug: Properly format runnable tasks in /proc/sched_debug
sched/numa: Only consider less busy nodes as numa balancing destinations
Revert 095bebf61a ("sched/numa: Do not move past the balance point if unbalanced")
sched/fair: Prevent throttling in early pick_next_task_fair()
preempt: Reorganize the notrace definitions a bit
preempt: Use preempt_schedule_context() as the official tracing preemption point
sched: Make preempt_schedule_context() function-tracing safe
x86: Remove cpu_sibling_mask() and cpu_core_mask()
x86: Replace cpu_**_mask() with topology_**_cpumask()
...
Commit 9470e4a693 only covered the initial bug report, there are
other spots in CFQ where we need to check that we actually have
a valid cfq_group_data structure.
Fixes: e48453c3 ("block, cgroup: implement policy-specific per-blkcg data")
Signed-off-by: Jens Axboe <axboe@fb.com>
If none of the devices in the system are using CFQ, then attempting to
read:
/sys/fs/cgroup/blkio/blkio.leaf_weight
will results in a NULL dereference. Check for a valid cfq_group_data
struct before attempting to dereference it.
Reported-by: Andrey Wagin <avagin@gmail.com>
Fixes: e48453c3 ("block, cgroup: implement policy-specific per-blkcg data")
Signed-off-by: Jens Axboe <axboe@fb.com>
If CFQ_GROUP_IOSCHED is not set, the compiler produces the
following warning:
CC block/cfq-iosched.o
linux/block/cfq-iosched.c:469:2:
warning: 'cpd_to_cfqgd' defined but not used [-Wunused-function]
*cpd_to_cfqgd(struct blkcg_policy_data *cpd)
^
In reality, two other lookup functions aren't used either if
CFQ_GROUP_IOSCHED isn't set. Move all three under one of the
CFQ_GROUP_IOSCHED sections in the code.
Reported-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
=================================
[ INFO: inconsistent lock state ]
4.1.0-rc7+ #217 Tainted: G O
---------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
swapper/6/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
(ext_devt_lock){+.?...}, at: [<ffffffff8143a60c>] blk_free_devt+0x3c/0x70
{SOFTIRQ-ON-W} state was registered at:
[<ffffffff810bf6b1>] __lock_acquire+0x461/0x1e70
[<ffffffff810c1947>] lock_acquire+0xb7/0x290
[<ffffffff818ac3a8>] _raw_spin_lock+0x38/0x50
[<ffffffff8143a07d>] blk_alloc_devt+0x6d/0xd0 <-- take the lock in process context
[..]
[<ffffffff810bf64e>] __lock_acquire+0x3fe/0x1e70
[<ffffffff810c00ad>] ? __lock_acquire+0xe5d/0x1e70
[<ffffffff810c1947>] lock_acquire+0xb7/0x290
[<ffffffff8143a60c>] ? blk_free_devt+0x3c/0x70
[<ffffffff818ac3a8>] _raw_spin_lock+0x38/0x50
[<ffffffff8143a60c>] ? blk_free_devt+0x3c/0x70
[<ffffffff8143a60c>] blk_free_devt+0x3c/0x70 <-- take the lock in softirq
[<ffffffff8143bfec>] part_release+0x1c/0x50
[<ffffffff8158edf6>] device_release+0x36/0xb0
[<ffffffff8145ac2b>] kobject_cleanup+0x7b/0x1a0
[<ffffffff8145aad0>] kobject_put+0x30/0x70
[<ffffffff8158f147>] put_device+0x17/0x20
[<ffffffff8143c29c>] delete_partition_rcu_cb+0x16c/0x180
[<ffffffff8143c130>] ? read_dev_sector+0xa0/0xa0
[<ffffffff810e0e0f>] rcu_process_callbacks+0x2ff/0xa90
[<ffffffff810e0dcf>] ? rcu_process_callbacks+0x2bf/0xa90
[<ffffffff81067e2e>] __do_softirq+0xde/0x600
Neil sees this in his tests and it also triggers on pmem driver unbind
for the libnvdimm tests. This fix is on top of an initial fix by Keith
for incorrect usage of mutex_lock() in this path: 2da78092dd "block:
Fix dev_t minor allocation lifetime". Both this and 2da78092dd are
candidates for -stable.
Fixes: 2da78092dd ("block: Fix dev_t minor allocation lifetime")
Cc: <stable@vger.kernel.org>
Cc: Keith Busch <keith.busch@intel.com>
Reported-by: NeilBrown <neilb@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
A previous commit wanted to make CFQ default to IOPS mode on
non-rotational storage, however it did so when the queue was
initialized and the non-rotational flag is only set later on
in the probe.
Add an elevator hook that gets called off the add_disk() path,
at that point we know that feature probing has finished, and
we can reliably check for the various flags that drivers can
set.
Fixes: 41c0126b ("block: Make CFQ default to IOPS mode on SSDs")
Tested-by: Romain Francoise <romain@orebokech.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Now blk_cleanup_queue() can be called before calling
del_gendisk()[1], inside which hctx->ctxs is touched
from blk_mq_unregister_hctx(), but the variable has
been freed by blk_cleanup_queue() at that time.
So this patch moves freeing of hctx->ctxs into queue's
release handler for fixing the oops reported by Stefan.
[1], 6cd18e711d (block: destroy bdi before blockdev is
unregistered)
Reported-by: Stefan Seyfried <stefan.seyfried@googlemail.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org (v4.0)
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The block IO (blkio) controller enables the block layer to provide service
guarantees in a hierarchical fashion. Specifically, service guarantees
are provided by registered request-accounting policies. As of now, a
proportional-share and a throttling policy are available. They are
implemented, respectively, by the CFQ I/O scheduler and the blk-throttle
subsystem. Unfortunately, as for adding new policies, the current
implementation of the block IO controller is only halfway ready to allow
new policies to be plugged in. This commit provides a solution to make
the block IO controller fully ready to handle new policies.
In what follows, we first describe briefly the current state, and then
list the changes made by this commit.
The throttling policy does not need any per-cgroup information to perform
its task. In contrast, the proportional share policy uses, for each cgroup,
both the weight assigned by the user to the cgroup, and a set of dynamically-
computed weights, one for each device.
The first, user-defined weight is stored in the blkcg data structure: the
block IO controller allocates a private blkcg data structure for each
cgroup in the blkio cgroups hierarchy (regardless of which policy is active).
In other words, the block IO controller internally mirrors the blkio cgroups
with private blkcg data structures.
On the other hand, for each cgroup and device, the corresponding dynamically-
computed weight is maintained in the following, different way. For each device,
the block IO controller keeps a private blkcg_gq structure for each cgroup in
blkio. In other words, block IO also keeps one private mirror copy of the blkio
cgroups hierarchy for each device, made of blkcg_gq structures.
Each blkcg_gq structure keeps per-policy information in a generic array of
dynamically-allocated 'dedicated' data structures, one for each registered
policy (so currently the array contains two elements). To be inserted into the
generic array, each dedicated data structure embeds a generic blkg_policy_data
structure. Consider now the array contained in the blkcg_gq structure
corresponding to a given pair of cgroup and device: one of the elements
of the array contains the dedicated data structure for the proportional-share
policy, and this dedicated data structure contains the dynamically-computed
weight for that pair of cgroup and device.
The generic strategy adopted for storing per-policy data in blkcg_gq structures
is already capable of handling new policies, whereas the one adopted with blkcg
structures is not, because per-policy data are hard-coded in the blkcg
structures themselves (currently only data related to the proportional-
share policy).
This commit addresses the above issues through the following changes:
. It generalizes blkcg structures so that per-policy data are stored in the same
way as in blkcg_gq structures.
Specifically, it lets also the blkcg structure store per-policy data in a
generic array of dynamically-allocated dedicated data structures. We will
refer to these data structures as blkcg dedicated data structures, to
distinguish them from the dedicated data structures inserted in the generic
arrays kept by blkcg_gq structures.
To allow blkcg dedicated data structures to be inserted in the generic array
inside a blkcg structure, this commit also introduces a new blkcg_policy_data
structure, which is the equivalent of blkg_policy_data for blkcg dedicated
data structures.
. It adds to the blkcg_policy structure, i.e., to the descriptor of a policy, a
cpd_size field and a cpd_init field, to be initialized by the policy with,
respectively, the size of the blkcg dedicated data structures, and the
address of a constructor function for blkcg dedicated data structures.
. It moves the CFQ-specific fields embedded in the blkcg data structure (i.e.,
the fields related to the proportional-share policy), into a new blkcg
dedicated data structure called cfq_group_data.
Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
CFQ idling causes reduced IOPS throughput on non-rotational disks.
Since disk head seeking is not applicable to SSDs, it doesn't really
help performance by anticipating future near-by IO requests.
By turning off idling (and switching to IOPS mode), we allow other
processes to dispatch IO requests down to the driver and so increase IO
throughput.
Following FIO benchmark results were taken on a cloud SSD offering with
idling on and off:
Idling iops avg-lat(ms) stddev bw
------------------------------------------------------
On 7054 90.107 38.697 28217KB/s
Off 29255 21.836 11.730 117022KB/s
fio --name=temp --size=100G --time_based --ioengine=libaio \
--randrepeat=0 --direct=1 --invalidate=1 --verify=0 \
--verify_fatal=0 --rw=randread --blocksize=4k --group_reporting=1 \
--filename=/dev/sdb --runtime=10 --iodepth=64 --numjobs=10
And the following is from a local SSD run:
Idling iops avg-lat(ms) stddev bw
------------------------------------------------------
On 19320 33.043 14.068 77281KB/s
Off 21626 29.465 12.662 86507KB/s
fio --name=temp --size=5G --time_based --ioengine=libaio \
--randrepeat=0 --direct=1 --invalidate=1 --verify=0 \
--verify_fatal=0 --rw=randread --blocksize=4k --group_reporting=1 \
--filename=/fio_data --runtime=10 --iodepth=64 --numjobs=10
Reviewed-by: Nauman Rafique <nauman@google.com>
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Now that bdi layer can handle per-blkcg bdi_writeback_congested state,
blk_{set|clear}_congested() can propagate non-root blkcg congestion
state to them.
This can be easily achieved by disabling the root_rl tests in
blk_{set|clear}_congested(). Note that we still need those tests when
!CONFIG_CGROUP_WRITEBACK as otherwise we'll end up flipping root blkcg
wb's congestion state for events happening on other blkcgs.
v2: Updated for bdi_writeback_congested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blk_{set|clear}_queue_congested() take @q and set or clear,
respectively, the congestion state of its bdi's root wb. Because bdi
used to be able to handle congestion state only on the root wb, the
callers of those functions tested whether the congestion is on the
root blkcg and skipped if not.
This is cumbersome and makes implementation of per cgroup
bdi_writeback congestion state propagation difficult. This patch
renames blk_{set|clear}_queue_congested() to
blk_{set|clear}_congested(), and makes them take request_list instead
of request_queue and test whether the specified request_list is the
root one before updating bdi_writeback congestion state. This makes
the tests in the callers unnecessary and simplifies them.
As there are no external users of these functions, the definitions are
moved from include/linux/blkdev.h to block/blk-core.c.
This patch doesn't introduce any noticeable behavior difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
A blkg (blkcg_gq) can be congested and decongested independently from
other blkgs on the same request_queue. Accordingly, for cgroup
writeback support, the congestion status at bdi (backing_dev_info)
should be split and updated separately from matching blkg's.
This patch prepares by adding blkg->wb_congested and associating a
blkg with its matching per-blkcg bdi_writeback_congested on creation.
v2: Updated to associate bdi_writeback_congested instead of
bdi_writeback.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
For the planned cgroup writeback support, on each bdi
(backing_dev_info), each memcg will be served by a separate wb
(bdi_writeback). This patch updates bdi so that a bdi can host
multiple wbs (bdi_writebacks).
On the default hierarchy, blkcg implicitly enables memcg. This allows
using memcg's page ownership for attributing writeback IOs, and every
memcg - blkcg combination can be served by its own wb by assigning a
dedicated wb to each memcg. This means that there may be multiple
wb's of a bdi mapped to the same blkcg. As congested state is per
blkcg - bdi combination, those wb's should share the same congested
state. This is achieved by tracking congested state via
bdi_writeback_congested structs which are keyed by blkcg.
bdi->wb remains unchanged and will keep serving the root cgroup.
cgwb's (cgroup wb's) for non-root cgroups are created on-demand or
looked up while dirtying an inode according to the memcg of the page
being dirtied or current task. Each cgwb is indexed on bdi->cgwb_tree
by its memcg id. Once an inode is associated with its wb, it can be
retrieved using inode_to_wb().
Currently, none of the filesystems has FS_CGROUP_WRITEBACK and all
pages will keep being associated with bdi->wb.
v3: inode_attach_wb() in account_page_dirtied() moved inside
mapping_cap_account_dirty() block where it's known to be !NULL.
Also, an unnecessary NULL check before kfree() removed. Both
detected by the kbuild bot.
v2: Updated so that wb association is per inode and wb is per memcg
rather than blkcg.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
cgroup writeback requires support from both bdi and filesystem sides.
Add BDI_CAP_CGROUP_WRITEBACK and FS_CGROUP_WRITEBACK to indicate
support and enable BDI_CAP_CGROUP_WRITEBACK on block based bdi's by
default. Also, define CONFIG_CGROUP_WRITEBACK which is enabled if
both MEMCG and BLK_CGROUP are enabled.
inode_cgwb_enabled() which determines whether a given inode's both bdi
and fs support cgroup writeback is added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
With the planned cgroup writeback support, backing-dev related
declarations will be more widely used across block and cgroup;
unfortunately, including backing-dev.h from include/linux/blkdev.h
makes cyclic include dependency quite likely.
This patch separates out backing-dev-defs.h which only has the
essential definitions and updates blkdev.h to include it. c files
which need access to more backing-dev details now include
backing-dev.h directly. This takes backing-dev.h off the common
include dependency chain making it a lot easier to use it across block
and cgroup.
v2: fs/fat build failure fixed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, a bdi (backing_dev_info) embeds single wb (bdi_writeback)
and the role of the separation is unclear. For cgroup support for
writeback IOs, a bdi will be updated to host multiple wb's where each
wb serves writeback IOs of a different cgroup on the bdi. To achieve
that, a wb should carry all states necessary for servicing writeback
IOs for a cgroup independently.
This patch moves bdi->state into wb.
* enum bdi_state is renamed to wb_state and the prefix of all enums is
changed from BDI_ to WB_.
* Explicit zeroing of bdi->state is removed without adding zeoring of
wb->state as the whole data structure is zeroed on init anyway.
* As there's still only one bdi_writeback per backing_dev_info, all
uses of bdi->state are mechanically replaced with bdi->wb.state
introducing no behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: drbd-dev@lists.linbit.com
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, a bio can only be associated with the io_context and blkcg
of %current using bio_associate_current(). This is too restrictive
for cgroup writeback support. Implement bio_associate_blkcg() which
associates a bio with the specified blkcg.
bio_associate_blkcg() leaves the io_context unassociated.
bio_associate_current() is updated so that it considers a bio as
already associated if it has a blkcg_css, instead of an io_context,
associated with it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
bio_associate_current() currently open codes task_css() and
css_tryget_online() to find and pin $current's blkcg css. Abstract it
into task_get_css() which is implemented from cgroup side. As a task
is always associated with an online css for every subsystem except
while the css_set update is propagating, task_get_css() retries till
css_tryget_online() succeeds.
This is a cleanup and shouldn't lead to noticeable behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Add global constant blkcg_root_css which points to &blkcg_root.css.
This will be used by cgroup writeback support. If blkcg is disabled,
it's defined as ERR_PTR(-EINVAL).
v2: The declarations moved to include/linux/blk-cgroup.h as suggested
by Vivek.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, blkcg does a minor optimization where the root blkcg is
created when the first blkcg policy is activated on a queue and
destroyed on the deactivation of the last. On systems where blkcg is
configured but not used, this saves one blkcg_gq struct per queue. On
systems where blkcg is actually used, there's no difference. The only
case where this can lead to any meaninful, albeit still minute, save
in memory consumption is when all blkcg policies are deactivated after
being widely used in the system, which is a hihgly unlikely scenario.
The conditional existence of root blkcg_gq has already created several
bugs in blkcg and became an issue once again for the new per-cgroup
wb_congested mechanism for cgroup writeback support leading to a NULL
dereference when no blkcg policy is active. This is really not worth
bothering with. This patch makes blkcg always allocate and link the
root blkcg_gq and release it only on queue destruction.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
cgroup aware writeback support will require exposing some of blkcg
details. In preprataion, move block/blk-cgroup.h to
include/linux/blk-cgroup.h. This patch is pure file move.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Storage controllers may expose multiple block devices that share hardware
resources managed by blk-mq. This patch enhances the shared tags so a
low-level driver can access the shared resources not tied to the unshared
h/w contexts. This way the LLD can dynamically add and delete disks and
request queues without having to track all the request_queue hctx's to
iterate outstanding tags.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
We can safely merge anything that wont generate an SG list entry,
so if the bio is data-less (discard), don't look at potential
SG gaps.
Signed-off-by: Jens Axboe <axboe@fb.com>
bdi_unregister() now contains very little functionality.
It contains a "WARN_ON" if bdi->dev is NULL. This warning is of no
real consequence as bdi->dev isn't needed by anything else in the function,
and it triggers if
blk_cleanup_queue() -> bdi_destroy()
is called before bdi_unregister, which happens since
Commit: 6cd18e711d ("block: destroy bdi before blockdev is unregistered.")
So this isn't wanted.
It also calls bdi_set_min_ratio(). This needs to be called after
writes through the bdi have all been flushed, and before the bdi is destroyed.
Calling it early is better than calling it late as it frees up a global
resource.
Calling it immediately after bdi_wb_shutdown() in bdi_destroy()
perfectly fits these requirements.
So bdi_unregister() can be discarded with the important content moved to
bdi_destroy(), as can the
writeback_bdi_unregister
event which is already not used.
Reported-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org (v4.0)
Fixes: c4db59d31e ("fs: don't reassign dirty inodes to default_backing_dev_info")
Fixes: 6cd18e711d ("block: destroy bdi before blockdev is unregistered.")
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Nicholas Moulin <nicholas.w.moulin@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently dm-multipath has to clone the bios for every request sent
to the lower devices, which wastes cpu cycles and ties down memory.
This patch instead adds a new REQ_CLONE flag that instructs req_bio_endio
to not complete bios attached to a request, which we set on clone
requests similar to bios in a flush sequence. With this change I/O
errors on a path failure only get propagated to dm-multipath, which
can then either resubmit the I/O or complete the bios on the original
request.
I've done some basic testing of this on a Linux target with ALUA support,
and it survives path failures during I/O nicely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for
non-chains") regressed all existing callers that followed this pattern:
1) saving a bio's original bi_end_io
2) wiring up an intermediate bi_end_io
3) restoring the original bi_end_io from intermediate bi_end_io
4) calling bio_endio() to execute the restored original bi_end_io
The regression was due to BIO_CHAIN only ever getting set if
bio_inc_remaining() is called. For the above pattern it isn't set until
step 3 above (step 2 would've needed to establish BIO_CHAIN). As such
the first bio_endio(), in step 2 above, never decremented __bi_remaining
before calling the intermediate bi_end_io -- leaving __bi_remaining with
the value 1 instead of 0. When bio_inc_remaining() occurred during step
3 it brought it to a value of 2. When the second bio_endio() was
called, in step 4 above, it should've called the original bi_end_io but
it didn't because there was an extra reference that wasn't dropped (due
to atomic operations being optimized away since BIO_CHAIN wasn't set
upfront).
Fix this issue by removing the __bi_remaining management complexity for
all callers that use the above pattern -- bio_chain() is the only
interface that _needs_ to be concerned with __bi_remaining. For the
above pattern callers just expect the bi_end_io they set to get called!
Remove bio_endio_nodec() and also remove all bio_inc_remaining() calls
that aren't associated with the bio_chain() interface.
Also, the bio_inc_remaining() interface has been moved local to bio.c.
Fixes: c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The only possible problem of using mutex_lock() instead of trylock
is about deadlock.
If there aren't any locks held before calling blkdev_reread_part(),
deadlock can't be caused by this conversion.
If there are locks held before calling blkdev_reread_part(),
and if these locks arn't required in open, close handler and I/O
path, deadlock shouldn't be caused too.
Both user space's ioctl(BLKRRPART) and md_setup_drive() from
init/do_mounts_md.c belongs to the 1st case, so the conversion is safe
for the two cases.
For loop, the previous patches in this pathset has fixed the ABBA lock
dependency, so the conversion is OK.
For nbd, tx_lock is held when calling the function:
- both open and release won't hold the lock
- when blkdev_reread_part() is run, I/O thread has been stopped
already, so tx_lock won't be acquired in I/O path at that time.
- so the conversion won't cause deadlock for nbd
For dasd, both dasd_open(), dasd_release() and request function don't
acquire any mutex/semphone, so the conversion should be safe.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This patch exports blkdev_reread_part() for block drivers, also
introduce __blkdev_reread_part().
For some drivers, such as loop, reread of partitions can be run
from the release path, and bd_mutex may already be held prior to
calling ioctl_by_bdev(bdev, BLKRRPART, 0), so introduce
__blkdev_reread_part for use in such cases.
CC: Christoph Hellwig <hch@lst.de>
CC: Jens Axboe <axboe@kernel.dk>
CC: Tejun Heo <tj@kernel.org>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Markus Pargmann <mpa@pengutronix.de>
CC: Stefan Weinhuber <wein@de.ibm.com>
CC: Stefan Haberland <stefan.haberland@de.ibm.com>
CC: Sebastian Ott <sebott@linux.vnet.ibm.com>
CC: Fabian Frederick <fabf@skynet.be>
CC: Ming Lei <ming.lei@canonical.com>
CC: David Herrmann <dh.herrmann@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: nbd-general@lists.sourceforge.net
CC: linux-s390@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Since the big barrier rewrite/removal in 2007 we never fail FLUSH or
FUA requests, which means we can remove the magic BIO_EOPNOTSUPP flag
to help propagating those to the buffer_head layer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
lockdep gets unhappy about the not disabling irqs when using the queue_lock
around it. Instead of trying to fix that up just switch to an atomic_t
and get rid of the lock.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
With commit ff36ab345 ("dm: remove request-based logic from
make_request_fn wrapper") DM no longer calls blk_queue_bio() directly,
so remove its export. Doing so required a forward declaration in
blk-core.c.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Last patch makes plug work for multiple queue case. However it only
works for single disk case, because it assumes only one request in the
plug list. If a task is accessing multiple disks, eg MD/DM, the
assumption is wrong. Let blk_attempt_plug_merge() record request from
the same queue.
V2: use NULL parameter in !mq case. Fix a bug. Add comments in
blk_attempt_plug_merge to make it less (hopefully) confusion.
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
plug is still helpful for workload with IO merge, but it can be harmful
otherwise especially with multiple hardware queues, as there is
(supposed) no lock contention in this case and plug can introduce
latency. For multiple queues, we do limited plug, eg plug only if there
is request merge. If a request doesn't have merge with following
request, the requet will be dispatched immediately.
V2: check blk_queue_nomerges() as suggested by Jeff.
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If we directly issue a request and it fails, we use
blk_mq_merge_queue_io(). But we already assigned bio to a request in
blk_mq_bio_to_request. blk_mq_merge_queue_io shouldn't run
blk_mq_bio_to_request again.
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The following appears in blk_sq_make_request:
/*
* If we have multiple hardware queues, just go directly to
* one of those for sync IO.
*/
We clearly don't have multiple hardware queues, here! This comment was
introduced with this commit 07068d5b8e (blk-mq: split make request
handler for multi and single queue):
We want slightly different behavior from them:
- On single queue devices, we currently use the per-process plug
for deferred IO and for merging.
- On multi queue devices, we don't use the per-process plug, but
we want to go straight to hardware for SYNC IO.
The old code had this:
use_plug = !is_flush_fua && ((q->nr_hw_queues == 1) || !is_sync);
and that was converted to:
use_plug = !is_flush_fua && !is_sync;
which is not equivalent. For the single queue case, that second half of
the && expression is always true. So, what I think was actually inteded
follows (and this more closely matches what is done in blk_queue_bio).
V2: delete the 'likely', which should not be a big deal
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Current code looks like inner plug gets flushed with a
blk_finish_plug(). Actually it's a nop. All requests/callbacks are added
to current->plug, while only outmost plug is assigned to current->plug.
So inner plug always has empty request/callback list, which makes
blk_flush_plug_list() a nop. This tries to make the code more clear.
Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This removes the request types and hacks from the block code and into the
old IDE driver. There is a small amunt of code duplication due to this,
but it's not too bad.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Struct bio has a reference count that controls when it can be freed.
Most uses cases is allocating the bio, which then returns with a
single reference to it, doing IO, and then dropping that single
reference. We can remove this atomic_dec_and_test() in the completion
path, if nobody else is holding a reference to the bio.
If someone does call bio_get() on the bio, then we flag the bio as
now having valid count and that we must properly honor the reference
count when it's being put.
Tested-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Struct bio has an atomic ref count for chained bio's, and we use this
to know when to end IO on the bio. However, most bio's are not chained,
so we don't need to always introduce this atomic operation as part of
ending IO.
Add a helper to elevate the bi_remaining count, and flag the bio as
now actually needing the decrement at end_io time. Rename the field
to __bi_remaining to catch any current users of this doing the
incrementing manually.
For high IOPS workloads, this reduces the overhead of bio_endio()
substantially.
Tested-by: Robert Elliott <elliott@hp.com>
Acked-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Normally if driver is busy to dispatch a request the logic is like below:
block layer: driver:
__blk_mq_run_hw_queue
a. blk_mq_stop_hw_queue
b. rq add to ctx->dispatch
later:
1. blk_mq_start_hw_queue
2. __blk_mq_run_hw_queue
But it's possible step 1-2 runs between a and b. And since rq isn't in
ctx->dispatch yet, step 2 will not run rq. The rq might get lost if
there are no subsequent requests kick in.
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Because of the peculiar way that md devices are created (automatically
when the device node is opened), a new device can be created and
registered immediately after the
blk_unregister_region(disk_devt(disk), disk->minors);
call in del_gendisk().
Therefore it is important that all visible artifacts of the previous
device are removed before this call. In particular, the 'bdi'.
Since:
commit c4db59d31e
Author: Christoph Hellwig <hch@lst.de>
fs: don't reassign dirty inodes to default_backing_dev_info
moved the
device_unregister(bdi->dev);
call from bdi_unregister() to bdi_destroy() it has been quite easy to
lose a race and have a new (e.g.) "md127" be created after the
blk_unregister_region() call and before bdi_destroy() is ultimately
called by the final 'put_disk', which must come after del_gendisk().
The new device finds that the bdi name is already registered in sysfs
and complains
> [ 9627.630029] WARNING: CPU: 18 PID: 3330 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x5a/0x70()
> [ 9627.630032] sysfs: cannot create duplicate filename '/devices/virtual/bdi/9:127'
We can fix this by moving the bdi_destroy() call out of
blk_release_queue() (which can happen very late when a refcount
reaches zero) and into blk_cleanup_queue() - which happens exactly when the md
device driver calls it.
Then it is only necessary for md to call blk_cleanup_queue() before
del_gendisk(). As loop.c devices are also created on demand by
opening the device node, we make the same change there.
Fixes: c4db59d31e
Reported-by: Azat Khuzhin <a3at.mail@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org (v4.0)
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Our issue is descripted in below call path:
->elevator_init
->elevator_init_fn
->{cfq,deadline,noop}_init_queue
->elevator_alloc
->kzalloc_node
fail to call kzalloc_node and then put module in elevator_alloc;
fail to call elevator_init_fn and then put module again in elevator_init.
Remove elevator_put invoking in error path of elevator_alloc to avoid
double release issue.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
hctx->tags has to be set as NULL in case that it is to be unmapped
no matter if set->tags[hctx->queue_num] is NULL or not in blk_mq_map_swqueue()
because shared tags can be freed already from another request queue.
The same situation has to be considered during handling CPU online too.
Unmapped hw queue can be remapped after CPU topo is changed, so we need
to allocate tags for the hw queue in blk_mq_map_swqueue(). Then tags
allocation for hw queue can be removed in hctx cpu online notifier, and it
is reasonable to do that after mapping is updated.
Cc: <stable@vger.kernel.org>
Reported-by: Dongsu Park <dongsu.park@profitbricks.com>
Tested-by: Dongsu Park <dongsu.park@profitbricks.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Firstly during CPU hotplug, even queue is freezed, timeout
handler still may come and access hctx->tags, which may cause
use after free, so this patch deactivates timeout handler
inside CPU hotplug notifier.
Secondly, tags can be shared by more than one queues, so we
have to check if the hctx has been unmapped, otherwise
still use-after-free on tags can be triggered.
Cc: <stable@vger.kernel.org>
Reported-by: Dongsu Park <dongsu.park@profitbricks.com>
Tested-by: Dongsu Park <dongsu.park@profitbricks.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit 889fa31f00 was a bit too eager in reducing the loop count,
so we ended up missing queues in some configurations. Ensure that
our division rounds up, so that's not the case.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 889fa31f00 ("blk-mq: reduce unnecessary software queue looping")
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull block layer core bits from Jens Axboe:
"This is the core pull request for 4.1. Not a lot of stuff in here for
this round, mostly little fixes or optimizations. This pull request
contains:
- An optimization that speeds up queue runs on blk-mq, especially for
the case where there's a large difference between nr_cpu_ids and
the actual mapped software queues on a hardware queue. From Chong
Yuan.
- Honor node local allocations for requests on legacy devices. From
David Rientjes.
- Cleanup of blk_mq_rq_to_pdu() from me.
- exit_aio() fixup from me, greatly speeding up exiting multiple IO
contexts off exit_group(). For my particular test case, fio exit
took ~6 seconds. A typical case of both exposing RCU grace periods
to user space, and serializing exit of them.
- Make blk_mq_queue_enter() honor the gfp mask passed in, so we only
wait if __GFP_WAIT is set. From Keith Busch.
- blk-mq exports and two added helpers from Mike Snitzer, which will
be used by the dm-mq code.
- Cleanups of blk-mq queue init from Wei Fang and Xiaoguang Wang"
* 'for-4.1/core' of git://git.kernel.dk/linux-block:
blk-mq: reduce unnecessary software queue looping
aio: fix serial draining in exit_aio()
blk-mq: cleanup blk_mq_rq_to_pdu()
blk-mq: put blk_queue_rq_timeout together in blk_mq_init_queue()
block: remove redundant check about 'set->nr_hw_queues' in blk_mq_alloc_tag_set()
block: allocate request memory local to request queue
blk-mq: don't wait in blk_mq_queue_enter() if __GFP_WAIT isn't set
blk-mq: export blk_mq_run_hw_queues
blk-mq: add blk_mq_init_allocated_queue and export blk_mq_register_disk
In flush_busy_ctxs() and blk_mq_hctx_has_pending(), regardless of how many
ctxs assigned to one hctx, they will all loop hctx->ctx_map.map_size
times. Here hctx->ctx_map.map_size is a const ALIGN(nr_cpu_ids, 8) / 8.
Especially, flush_busy_ctxs() is in hot code path. And it's unnecessary.
Change ->map_size to contain the actually mapped software queues, so we
only loop for as many iterations as we have to.
And remove cpumask setting and nr_ctx count in blk_mq_init_cpu_queues()
since they are all re-done in blk_mq_map_swqueue().
blk_mq_map_swqueue().
Signed-off-by: Chong Yuan <chong.yuan@memblaze.com>
Reviewed-by: Wenbo Wang <wenbo.wang@memblaze.com>
Updated by me for formatting and commenting.
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull vfs update from Al Viro:
"Part one:
- struct filename-related cleanups
- saner iov_iter_init() replacements (and switching the syscalls to
use of those)
- ntfs switch to ->write_iter() (Anton)
- aio cleanups and splitting iocb into common and async parts
(Christoph)
- assorted fixes (me, bfields, Andrew Elble)
There's a lot more, including the completion of switchover to
->{read,write}_iter(), d_inode/d_backing_inode annotations, f_flags
race fixes, etc, but that goes after #for-davem merge. David has
pulled it, and once it's in I'll send the next vfs pull request"
* 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (35 commits)
sg_start_req(): use import_iovec()
sg_start_req(): make sure that there's not too many elements in iovec
blk_rq_map_user(): use import_single_range()
sg_io(): use import_iovec()
process_vm_access: switch to {compat_,}import_iovec()
switch keyctl_instantiate_key_common() to iov_iter
switch {compat_,}do_readv_writev() to {compat_,}import_iovec()
aio_setup_vectored_rw(): switch to {compat_,}import_iovec()
vmsplice_to_user(): switch to import_iovec()
kill aio_setup_single_vector()
aio: simplify arguments of aio_setup_..._rw()
aio: lift iov_iter_init() into aio_setup_..._rw()
lift iov_iter into {compat_,}do_readv_writev()
NFS: fix BUG() crash in notify_change() with patch to chown_common()
dcache: return -ESTALE not -EBUSY on distributed fs race
NTFS: Version 2.1.32 - Update file write from aio_write to write_iter.
VFS: Add iov_iter_fault_in_multipages_readable()
drop bogus check in file_open_root()
switch security_inode_getattr() to struct path *
constify tomoyo_realpath_from_path()
...
Jan Engelhardt reports a strange oops with an invalid ->sense_buffer
pointer in scsi_init_cmd_errh() with the blk-mq code.
The sense_buffer pointer should have been initialized by the call to
scsi_init_request() from blk_mq_init_rq_map(), but there seems to be
some non-repeatable memory corruptor.
This patch makes sure we initialize the whole struct request allocation
(and the associated 'struct scsi_cmnd' for the SCSI case) to zero, by
using __GFP_ZERO in the allocation. The old code initialized a couple
of individual fields, leaving the rest undefined (although many of them
are then initialized in later phases, like blk_mq_rq_ctx_init() etc.
It's not entirely clear why this matters, but it's the rigth thing to do
regardless, and with 4.0 imminent this is the defensive "let's just make
sure everything is initialized properly" patch.
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linux 3.19 commit 69c953c ("lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n")
caused blk_stack_limits() to not properly stack queue_limits for stacked
devices (e.g. DM).
Fix this regression by establishing lcm_not_zero() and switching
blk_stack_limits() over to using it.
DM uses blk_set_stacking_limits() to establish the initial top-level
queue_limits that are then built up based on underlying devices' limits
using blk_stack_limits(). In the case of optimal_io_size (io_opt)
blk_set_stacking_limits() establishes a default value of 0. With commit
69c953c, lcm(0, n) is no longer n, which compromises proper stacking of
the underlying devices' io_opt.
Test:
$ modprobe scsi_debug dev_size_mb=10 num_tgts=1 opt_blks=1536
$ cat /sys/block/sde/queue/optimal_io_size
786432
$ dmsetup create node --table "0 100 linear /dev/sde 0"
Before this fix:
$ cat /sys/block/dm-5/queue/optimal_io_size
0
After this fix:
$ cat /sys/block/dm-5/queue/optimal_io_size
786432
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.19+
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
At the beginning of blk_mq_alloc_tag_set(), we have already checked whether
'set->nr_hw_queues' is zero, so here remove this redundant check.
Signed-off-by: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
blk_init_rl() allocates a mempool using mempool_create_node() with node
local memory. This only allocates the mempool and element list locally
to the requeue queue node.
What we really want to do is allocate the request itself local to the
queue. To do this, we need our own alloc and free functions that will
allocate from request_cachep and pass the request queue node in to prefer
node local memory.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Use the right array index to reference the last
element of rq->biotail->bi_io_vec[]
Signed-off-by: Wenbo Wang <wenbo.wang@memblaze.com>
Reviewed-by: Chong Yuan <chong.yuan@memblaze.com>
Fixes: 66cb45aa41 ("block: add support for limiting gaps in SG lists")
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
When allocating from the reserved tags pool, bt_get() is called with
a NULL hctx. If all tags are in use, the hw queue is kicked to push
out any pending IO, potentially freeing tags, and tag allocation is
retried. The problem is that blk_mq_run_hw_queue() doesn't check for
a NULL hctx. So we avoid it with a simple NULL hctx test.
Tested by hammering mtip32xx with concurrent smartctl/hdparm.
Signed-off-by: Sam Bradshaw <sbradshaw@micron.com>
Signed-off-by: Selvan Mani <smani@micron.com>
Fixes: b32232073e ("blk-mq: fix hang in bt_get()")
Cc: stable@kernel.org
Added appropriate comment.
Signed-off-by: Jens Axboe <axboe@fb.com>
Return -EBUSY if we're unable to enter a queue immediately when
allocating a blk-mq request without __GFP_WAIT.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Rename blk_mq_run_queues to blk_mq_run_hw_queues, add async argument,
and export it.
DM's suspend support must be able to run the queue without starting
stopped hw queues.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Add a variant of blk_mq_init_queue that allows a previously allocated
queue to be initialized. blk_mq_init_allocated_queue models
blk_init_allocated_queue -- which was also created for DM's use.
DM's approach to device creation requires a placeholder request_queue be
allocated for use with alloc_dev() but the decision about what type of
request_queue will be ultimately created is deferred until all component
devices referenced in the DM table are processed to determine the table
type (request-based, blk-mq request-based, or bio-based).
Also, because of DM's late finalization of the request_queue type
the call to blk_mq_register_disk() doesn't happen during alloc_dev().
Must export blk_mq_register_disk() so that DM can backfill the 'mq' dir
once the blk-mq queue is fully allocated.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If percpu_ref_init() fails the allocated q and hctxs must get cleaned
up; using 'err_map' doesn't allow that to happen.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull block driver changes from Jens Axboe:
"This contains:
- The 4k/partition fixes for brd from Boaz/Matthew.
- A few xen front/back block fixes from David Vrabel and Roger Pau
Monne.
- Floppy changes from Takashi, cleaning the device file creation.
- Switching libata to use the new blk-mq tagging policy, removing
code (and a suboptimal implementation) from libata. This will
throw you a merge conflict, since a bug in the original libata
tagging code was fixed since this code was branched. Trivial.
From Shaohua.
- Conversion of loop to blk-mq, from Ming Lei.
- Cleanup of the io_schedule() handling in bsg from Peter Zijlstra.
He claims it improves on unreadable code, which will cost him a
beer.
- Maintainer update or NDB, now handled by Markus Pargmann.
- NVMe:
- Optimization from me that avoids a kmalloc/kfree per IO for
smaller (<= 8KB) IO. This cuts about 1% of high IOPS CPU
overhead.
- Removal of (now) dead RCU code, a relic from before NVMe was
converted to blk-mq"
* 'for-3.20/drivers' of git://git.kernel.dk/linux-block:
xen-blkback: default to X86_32 ABI on x86
xen-blkfront: fix accounting of reqs when migrating
xen-blkback,xen-blkfront: add myself as maintainer
block: Simplify bsg complete all
floppy: Avoid manual call of device_create_file()
NVMe: avoid kmalloc/kfree for smaller IO
MAINTAINERS: Update NBD maintainer
libata: make sata_sil24 use fifo tag allocator
libata: move sas ata tag allocation to libata-scsi.c
libata: use blk taging
NVMe: within nvme_free_queues(), delete RCU sychro/deferred free
null_blk: suppress invalid partition info
brd: Request from fdisk 4k alignment
brd: Fix all partitions BUGs
axonram: Fix bug in direct_access
loop: add blk-mq.h include
block: loop: don't handle REQ_FUA explicitly
block: loop: introduce lo_discard() and lo_req_flush()
block: loop: say goodby to bio
block: loop: improve performance via blk-mq
Pull core block IO changes from Jens Axboe:
"This contains:
- A series from Christoph that cleans up and refactors various parts
of the REQ_BLOCK_PC handling. Contributions in that series from
Dongsu Park and Kent Overstreet as well.
- CFQ:
- A bug fix for cfq for realtime IO scheduling from Jeff Moyer.
- A stable patch fixing a potential crash in CFQ in OOM
situations. From Konstantin Khlebnikov.
- blk-mq:
- Add support for tag allocation policies, from Shaohua. This is
a prep patch enabling libata (and other SCSI parts) to use the
blk-mq tagging, instead of rolling their own.
- Various little tweaks from Keith and Mike, in preparation for
DM blk-mq support.
- Minor little fixes or tweaks from me.
- A double free error fix from Tony Battersby.
- The partition 4k issue fixes from Matthew and Boaz.
- Add support for zero+unprovision for blkdev_issue_zeroout() from
Martin"
* 'for-3.20/core' of git://git.kernel.dk/linux-block: (27 commits)
block: remove unused function blk_bio_map_sg
block: handle the null_mapped flag correctly in blk_rq_map_user_iov
blk-mq: fix double-free in error path
block: prevent request-to-request merging with gaps if not allowed
blk-mq: make blk_mq_run_queues() static
dm: fix multipath regression due to initializing wrong request
cfq-iosched: handle failure of cfq group allocation
block: Quiesce zeroout wrapper
block: rewrite and split __bio_copy_iov()
block: merge __bio_map_user_iov into bio_map_user_iov
block: merge __bio_map_kern into bio_map_kern
block: pass iov_iter to the BLOCK_PC mapping functions
block: add a helper to free bio bounce buffer pages
block: use blk_rq_map_user_iov to implement blk_rq_map_user
block: simplify bio_map_kern
block: mark blk-mq devices as stackable
block: keep established cmd_flags when cloning into a blk-mq request
block: add blk-mq support to blk_insert_cloned_request()
block: require blk_rq_prep_clone() be given an initialized clone request
blk-mq: add tag allocation policy
...
Pull backing device changes from Jens Axboe:
"This contains a cleanup of how the backing device is handled, in
preparation for a rework of the life time rules. In this part, the
most important change is to split the unrelated nommu mmap flags from
it, but also removing a backing_dev_info pointer from the
address_space (and inode), and a cleanup of other various minor bits.
Christoph did all the work here, I just fixed an oops with pages that
have a swap backing. Arnd fixed a missing export, and Oleg killed the
lustre backing_dev_info from staging. Last patch was from Al,
unexporting parts that are now no longer needed outside"
* 'for-3.20/bdi' of git://git.kernel.dk/linux-block:
Make super_blocks and sb_lock static
mtd: export new mtd_mmap_capabilities
fs: make inode_to_bdi() handle NULL inode
staging/lustre/llite: get rid of backing_dev_info
fs: remove default_backing_dev_info
fs: don't reassign dirty inodes to default_backing_dev_info
nfs: don't call bdi_unregister
ceph: remove call to bdi_unregister
fs: remove mapping->backing_dev_info
fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
nilfs2: set up s_bdi like the generic mount_bdev code
block_dev: get bdev inode bdi directly from the block device
block_dev: only write bdev inode on close
fs: introduce f_op->mmap_capabilities for nommu mmap support
fs: kill BDI_CAP_SWAP_BACKED
fs: deduplicate noop_backing_dev_info
The tape drivers (and the sg driver in a special case that doesn't matter
here) use the null_mapped flag to tell blk_rq_map_user to not copy around
any data into or out of the bounce buffers. blk_rq_map_user_iov never
got that treatment, which didn't matter until I refactored blk_rq_map_user
to be implemented in terms of blk_rq_map_user_iov.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixes: ddad8dd0a1 ("block: use blk_rq_map_user_iov to implement blk_rq_map_user")
Signed-off-by: Jens Axboe <axboe@fb.com>
If the allocation of bt->bs fails, then bt->map can be freed twice, once
in blk_mq_init_bitmap_tags() -> bt_alloc(), and once in
blk_mq_init_bitmap_tags() -> bt_free(). Fix by setting the pointer to
NULL after the first free.
Cc: <stable@vger.kernel.org>
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
If the queue has SG_GAPS set, we must not merge across an sg gap.
This is caught for the bio case, but currently not for the
more rare case of merging two requests directly.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Cut the dm bits, those will go through the dm tree, and fixed
the test_bit() test.
Signed-off-by: Jens Axboe <axboe@fb.com>
We no longer use it outside of blk-mq.c, so we can make it static
and stop exporting it. Additionally, kill the 'async' argument, as
there's only one used of it.
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull EFI updates from Ingo Molnar:
"Main changes:
- Move efivarfs from the misc filesystem section to pseudo filesystem
- Expose firmware platform size in sysfs
- Improve robustness of get_memory_map() by removing assumptions on
the size of efi_memory_desc_t.
- various cleanups and fixes
The biggest risk is the get_memory_map() change, which changes the way
that both the arm64 and x86 EFI boot stub build the early memory map.
There are no known regressions with it at the moment, BYMMV"
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: Don't look for chosen@0 node on DT platforms
firmware: efi: Remove unneeded guid unparse
efi/libstub: Call get_memory_map() to obtain map and desc sizes
efi: Small leak on error in runtime map code
efi: rtc-efi: Mark UIE as unsupported
arm64/efi: efistub: Apply __init annotation
efi: Expose underlying UEFI firmware platform size to userland
efi: Rename efi_guid_unparse to efi_guid_to_str
efi: Update the URLs for efibootmgr
fs: Make efivarfs a pseudo filesystem, built by default with EFI
Cfq_lookup_create_cfqg() allocates struct blkcg_gq using GFP_ATOMIC.
In cfq_find_alloc_queue() possible allocation failure is not handled.
As a result kernel oopses on NULL pointer dereference when
cfq_link_cfqq_cfqg() calls cfqg_get() for NULL pointer.
Bug was introduced in v3.5 in commit cd1604fab4 ("blkcg: factor
out blkio_group creation"). Prior to that commit cfq group lookup
had returned pointer to root group as fallback.
This patch handles this error using existing fallback oom_cfqq.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Fixes: cd1604fab4 ("blkcg: factor out blkio_group creation")
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
blkdev_issue_zeroout() printed a warning if a device failed a discard or
write same request despite advertising support for these. That's fine
for SCSI since we'll disable these commands if we get an error back from
the disk saying that they are not supported. And consequently the
warning only gets printed once.
There are other types of block devices that support discard, however,
and these may return -EOPNOTSUPP for each command but leave discard
enabled in the queue limits. This will cause a warning message for every
blkdev_issue_zeroout() invocation.
Remove the offending warning messages.
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Rewrite __bio_copy_iov using the copy_page_{from,to}_iter helpers, and
split it into two simpler functions.
This commit should contain only literal replacements, without
functional changes.
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dongsu Park <dongsu.park@profitbricks.com>
[hch: removed the __bio_copy_iov wrapper]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
And also remove the unused bdev argument.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This saves a little code, and allow to simplify the error handling.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Dan Williams