Improves __load_mapping_v1() and __load_mapping_v2() DMERR messages to
explicitly name the cache block number whose mapping couldn't be
loaded.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If "metadata2" is provided as a table argument when creating/loading a
cache target a more compact metadata format, with separate dirty bits,
is used. "metadata2" improves speed of shutting down a cache target.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
dm_btree_del() is called from an ioctl so don't recurse into FS.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The metadata_space_map_root passed to sm_ll_open_metadata() may or may
not be arch aligned, use memcpy to ensure it is. This is not a fast
path so the extra memcpy doesn't hurt us.
Long-term it'd be better to use the kernel's alignment infrastructure to
remove the memcpy()s that are littered across persistent-data (btree,
array, space-maps, etc).
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
A rounding bug due to compiler generated temporary being 32bit was found
in remap_to_cache(). A localized cast in remap_to_cache() fixes the
corruption but this preferred fix (changing from uint32_t to sector_t)
eliminates potential for future rounding errors elsewhere.
Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Firstly bio_clone_mddev() is used in raid normal I/O and isn't
in resync I/O path.
Secondly all the direct access to bvec table in raid happens on
resync I/O except for write behind of raid1, in which we still
use bio_clone() for allocating new bvec table.
So this patch replaces bio_clone() with bio_clone_fast()
in bio_clone_mddev().
Also kill bio_clone_mddev() and call bio_clone_fast() directly, as
suggested by Christoph Hellwig.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
mddev is never NULL and neither is ->bio_set, so
remove the check.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Write behind need to replace pages in bio's bvecs, and we have
to clone a fresh bio with new bvec table, so use the introduced
bio_clone_bioset_partial() for it.
For other bio_clone_mddev() cases, we will use fast clone since
they don't need to touch bvec table.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The current behaviour is to fall back to allocate
bio from 'fs_bio_set', that isn't a correct way
because it might cause deadlock.
So this patch simply return failure if mddev->bio_set
can't be created.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
This makes md do the same thing as dm for write same IO failure. Please
see 7eee4ae(dm: disable WRITE SAME if it fails) for details why we need
this.
We did a little bit different than dm. Instead of disabling writesame in
the first IO error, we disable it till next writesame IO coming after
the first IO error. This way we don't need to clone a bio.
Also reported here: https://bugzilla.kernel.org/show_bug.cgi?id=118581
Suggested-by: NeilBrown <neilb@suse.com>
Acked-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
stripes which are being reclaimed are still accounted into cached
stripes. The reclaim takes time. r5c_do_reclaim isn't aware of the
stripes and does unnecessary stripe reclaim. In practice, I saw one
stripe is reclaimed one time. This will cause bad IO pattern. Fixing
this by excluding the reclaing stripes in the check.
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
When log space is tight, we try to reclaim stripes from log head. There
are stripes which can't be reclaimed right now if some conditions are
met. We skip such stripes but accidentally count them, which might cause
no stripes are claimed. Fixing this by only counting valid stripes.
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Commit: cbd1998377 ("md: Fix unfortunate interaction with evms")
change mddev_put() so that it would not destroy an md device while
->ctime was non-zero.
Unfortunately, we didn't make sure to clear ->ctime when unloading
the module, so it is possible for an md device to remain after
module unload. An attempt to open such a device will trigger
an invalid memory reference in:
get_gendisk -> kobj_lookup -> exact_lock -> get_disk
when tring to access disk->fops, which was in the module that has
been removed.
So ensure we clear ->ctime in md_exit(), and explain how that is useful,
as it isn't immediately obvious when looking at the code.
Fixes: cbd1998377 ("md: Fix unfortunate interaction with evms")
Tested-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
It is important to be able to flush all stripes in raid5-cache.
Therefore, we need reserve some space on the journal device for
these flushes. If flush operation includes pending writes to the
stripe, we need to reserve (conf->raid_disk + 1) pages per stripe
for the flush out. This reduces the efficiency of journal space.
If we exclude these pending writes from flush operation, we only
need (conf->max_degraded + 1) pages per stripe.
With this patch, when log space is critical (R5C_LOG_CRITICAL=1),
pending writes will be excluded from stripe flush out. Therefore,
we can reduce reserved space for flush out and thus improve journal
device efficiency.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Chunk aligned read significantly reduces CPU usage of raid456.
However, it is not safe to fully bypass the write back cache.
This patch enables chunk aligned read with write back cache.
For chunk aligned read, we track stripes in write back cache at
a bigger granularity, "big_stripe". Each chunk may contain more
than one stripe (for example, a 256kB chunk contains 64 4kB-page,
so this chunk contain 64 stripes). For chunk_aligned_read, these
stripes are grouped into one big_stripe, so we only need one lookup
for the whole chunk.
For each big_stripe, struct big_stripe_info tracks how many stripes
of this big_stripe are in the write back cache. We count how many
stripes of this big_stripe are in the write back cache. These
counters are tracked in a radix tree (big_stripe_tree).
r5c_tree_index() is used to calculate keys for the radix tree.
chunk_aligned_read() calls r5c_big_stripe_cached() to look up
big_stripe of each chunk in the tree. If this big_stripe is in the
tree, chunk_aligned_read() aborts. This look up is protected by
rcu_read_lock().
It is necessary to remember whether a stripe is counted in
big_stripe_tree. Instead of adding new flag, we reuses existing flags:
STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE. If either of these
two flags are set, the stripe is counted in big_stripe_tree. This
requires moving set_bit(STRIPE_R5C_PARTIAL_STRIPE) to
r5c_try_caching_write(); and moving clear_bit of
STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE to
r5c_finish_stripe_write_out().
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
We made raid5 stripe handling multi-thread before. It works well for
SSD. But for harddisk, the multi-threading creates more disk seek, so
not always improve performance. For several hard disks based raid5,
multi-threading is required as raid5d becames a bottleneck especially
for sequential write.
To overcome the disk seek issue, we only dispatch IO from raid5d if the
array is harddisk based. Other threads can still handle stripes, but
can't dispatch IO.
Idealy, we should control IO dispatching order according to IO position
interrnally. Right now we still depend on block layer, which isn't very
efficient sometimes though.
My setup has 9 harddisks, each disk can do around 180M/s sequential
write. So in theory, the raid5 can do 180 * 8 = 1440M/s sequential
write. The test machine uses an ATOM CPU. I measure sequential write
with large iodepth bandwidth to raid array:
without patch: ~600M/s
without patch and group_thread_cnt=4: 750M/s
with patch and group_thread_cnt=4: 950M/s
with patch, group_thread_cnt=4, skip_copy=1: 1150M/s
We are pretty close to the maximum bandwidth in the large iodepth
iodepth case. The performance gap of small iodepth sequential write
between software raid and theory value is still very big though, because
we don't have an efficient pipeline.
Cc: NeilBrown <neilb@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Recently I receive a bug report that on Linux v3.0 based kerenl, hot add
disk to a md linear device causes kernel crash at linear_congested(). From
the crash image analysis, I find in linear_congested(), mddev->raid_disks
contains value N, but conf->disks[] only has N-1 pointers available. Then
a NULL pointer deference crashes the kernel.
There is a race between linear_add() and linear_congested(), RCU stuffs
used in these two functions cannot avoid the race. Since Linuv v4.0
RCU code is replaced by introducing mddev_suspend(). After checking the
upstream code, it seems linear_congested() is not called in
generic_make_request() code patch, so mddev_suspend() cannot provent it
from being called. The possible race still exists.
Here I explain how the race still exists in current code. For a machine
has many CPUs, on one CPU, linear_add() is called to add a hard disk to a
md linear device; at the same time on other CPU, linear_congested() is
called to detect whether this md linear device is congested before issuing
an I/O request onto it.
Now I use a possible code execution time sequence to demo how the possible
race happens,
seq linear_add() linear_congested()
0 conf=mddev->private
1 oldconf=mddev->private
2 mddev->raid_disks++
3 for (i=0; i<mddev->raid_disks;i++)
4 bdev_get_queue(conf->disks[i].rdev->bdev)
5 mddev->private=newconf
In linear_add() mddev->raid_disks is increased in time seq 2, and on
another CPU in linear_congested() the for-loop iterates conf->disks[i] by
the increased mddev->raid_disks in time seq 3,4. But conf with one more
element (which is a pointer to struct dev_info type) to conf->disks[] is
not updated yet, accessing its structure member in time seq 4 will cause a
NULL pointer deference fault.
To fix this race, there are 2 parts of modification in the patch,
1) Add 'int raid_disks' in struct linear_conf, as a copy of
mddev->raid_disks. It is initialized in linear_conf(), always being
consistent with pointers number of 'struct dev_info disks[]'. When
iterating conf->disks[] in linear_congested(), use conf->raid_disks to
replace mddev->raid_disks in the for-loop, then NULL pointer deference
will not happen again.
2) RCU stuffs are back again, and use kfree_rcu() in linear_add() to
free oldconf memory. Because oldconf may be referenced as mddev->private
in linear_congested(), kfree_rcu() makes sure that its memory will not
be released until no one uses it any more.
Also some code comments are added in this patch, to make this modification
to be easier understandable.
This patch can be applied for kernels since v4.0 after commit:
3be260cc18 ("md/linear: remove rcu protections in favour of
suspend/resume"). But this bug is reported on Linux v3.0 based kernel, for
people who maintain kernels before Linux v4.0, they need to do some back
back port to this patch.
Changelog:
- V3: add 'int raid_disks' in struct linear_conf, and use kfree_rcu() to
replace rcu_call() in linear_add().
- v2: add RCU stuffs by suggestion from Shaohua and Neil.
- v1: initial effort.
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Shaohua Li <shli@fb.com>
Cc: Neil Brown <neilb@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Shaohua Li <shli@fb.com>
.. at least for unprivileged users. Before we called into the SCSI
ioctl code to allow excemptions for a few SCSI passthrough ioctls,
but this is pretty unsafe and except for this call dm knows nothing
about SCSI ioctls.
As the SCSI ioctl code is now optional, we really don't want to
drag it in for DM, and the exception is not very useful anyway.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
The lockdep splat below hints at a bug in RCU usage in dm-crypt that
was introduced with commit c538f6ec9f ("dm crypt: add ability to use
keys from the kernel key retention service"). The kernel keyring
function user_key_payload() is in fact a wrapper for
rcu_dereference_protected() which must not be called with only
rcu_read_lock() section mark.
Unfortunately the kernel keyring subsystem doesn't currently provide
an interface that allows the use of an RCU read-side section. So for
now we must drop RCU in favour of rwsem until a proper function is
made available in the kernel keyring subsystem.
===============================
[ INFO: suspicious RCU usage. ]
4.10.0-rc5 #2 Not tainted
-------------------------------
./include/keys/user-type.h:53 suspicious rcu_dereference_protected() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
2 locks held by cryptsetup/6464:
#0: (&md->type_lock){+.+.+.}, at: [<ffffffffa02472a2>] dm_lock_md_type+0x12/0x20 [dm_mod]
#1: (rcu_read_lock){......}, at: [<ffffffffa02822f8>] crypt_set_key+0x1d8/0x4b0 [dm_crypt]
stack backtrace:
CPU: 1 PID: 6464 Comm: cryptsetup Not tainted 4.10.0-rc5 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
Call Trace:
dump_stack+0x67/0x92
lockdep_rcu_suspicious+0xc5/0x100
crypt_set_key+0x351/0x4b0 [dm_crypt]
? crypt_set_key+0x1d8/0x4b0 [dm_crypt]
crypt_ctr+0x341/0xa53 [dm_crypt]
dm_table_add_target+0x147/0x330 [dm_mod]
table_load+0x111/0x350 [dm_mod]
? retrieve_status+0x1c0/0x1c0 [dm_mod]
ctl_ioctl+0x1f5/0x510 [dm_mod]
dm_ctl_ioctl+0xe/0x20 [dm_mod]
do_vfs_ioctl+0x8e/0x690
? ____fput+0x9/0x10
? task_work_run+0x7e/0xa0
? trace_hardirqs_on_caller+0x122/0x1b0
SyS_ioctl+0x3c/0x70
entry_SYSCALL_64_fastpath+0x18/0xad
RIP: 0033:0x7f392c9a4ec7
RSP: 002b:00007ffef6383378 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffef63830a0 RCX: 00007f392c9a4ec7
RDX: 000000000124fcc0 RSI: 00000000c138fd09 RDI: 0000000000000005
RBP: 00007ffef6383090 R08: 00000000ffffffff R09: 00000000012482b0
R10: 2a28205d34383336 R11: 0000000000000246 R12: 00007f392d803a08
R13: 00007ffef63831e0 R14: 0000000000000000 R15: 00007f392d803a0b
Fixes: c538f6ec9f ("dm crypt: add ability to use keys from the kernel key retention service")
Reported-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Fixes a crash in dm_table_find_target() due to a NULL struct dm_table
being passed from dm_old_request_fn() that races with DM device
destruction.
Reported-by: artem@flashgrid.io
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
We will want to have struct backing_dev_info allocated separately from
struct request_queue. As the first step add pointer to backing_dev_info
to request_queue and convert all users touching it. No functional
changes in this patch.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
DM already calls blk_mq_alloc_request on the request_queue of the
underlying device if it is a blk-mq device. But now that we allow drivers
to allocate additional data and initialize it ahead of time we need to do
the same for all drivers. Doing so and using the new cmd_size
infrastructure in the block layer greatly simplifies the dm-rq and mpath
code, and should also make arbitrary combinations of SQ and MQ devices
with SQ or MQ device mapper tables easily possible as a further step.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
DM tries to copy a few fields around for BLOCK_PC requests, but given
that no dm-target ever wires up scsi_cmd_ioctl BLOCK_PC can't actually
be sent to dm.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Return an errno value instead of the passed in queue so that the callers
don't have to keep track of two queues, and move the assignment of the
request_fn and lock to the caller as passing them as argument doesn't
simplify anything. While we're at it also remove two pointless NULL
assignments, given that the request structure is zeroed on allocation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
No need for the local variables, the bio is still live and we can just
assign the bits we want directly. Make me wonder why we can't assign
all the bio flags to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This centralizes the checks for bios that needs to be go into the flush
state machine.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
For consistency, call read_disk_sb() from
attempt_restore_of_faulty_devices() instead
of calling sync_page_io() directly.
Explicitly set device to faulty on superblock read error.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add md raid4/5/6 journaling support (upstream commit bac624f3f8 started
the implementation) which closes the write hole (i.e. non-atomic updates
to stripes) using a dedicated journal device.
Background:
raid4/5/6 stripes hold N data payloads per stripe plus one parity raid4/5
or two raid6 P/Q syndrome payloads in an in-memory stripe cache.
Parity or P/Q syndromes used to recover any data payloads in case of a disk
failure are calculated from the N data payloads and need to be updated on the
different component devices of the raid device. Those are non-atomic,
persistent updates. Hence a crash can cause failure to update all stripe
payloads persistently and thus cause data loss during stripe recovery.
This problem gets addressed by writing whole stripe cache entries (together with
journal metadata) to a persistent journal entry on a dedicated journal device.
Only if that journal entry is written successfully, the stripe cache entry is
updated on the component devices of the raid device (i.e. writethrough type).
In case of a crash, the entry can be recovered from the journal and be written
again thus ensuring consistent stripe payload suitable to data recovery.
Future dependencies:
once writeback caching being worked on to compensate for the throughput
implictions involved with writethrough overhead is supported with journaling
in upstream, an additional patch based on this one will support it in dm-raid.
Journal resilience related remarks:
because stripes are recovered from the journal in case of a crash, the
journal device better be resilient. Resilience becomes mandatory with
future writeback support, because loosing the working set in the log
means data loss as oposed to writethrough, were the loss of the
journal device 'only' reintroduces the write hole.
Fix comment on data offsets in parse_dev_params() and initialize
new_data_offset as well.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
During raid set resize checks and setting up the recovery offset in case a raid
set grows, calculated rd->md.dev_sectors is compared to rs->dev[0].rdev.sectors.
Device 0 may not be defined in case userspace passes in '- -' for it
(lvm2 doesn't do that so far), thus it's device sectors can't be taken
authoritatively in this comparison and another valid device must be used
to retrieve the device size.
Use mddev->dev_sectors in checking for ongoing recovery for the same reason.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This fix addresses the following 3 failure scenarios:
1) If a (transiently) inaccessible metadata device is being passed into the
constructor (e.g. a device tuple '254:4 254:5'), it is processed as if
'- -' was given. This erroneously results in a status table line containing
'- -', which mistakenly differs from what has been passed in. As a result,
userspace libdevmapper puts the device tuple seperate from the RAID device
thus not processing the dependencies properly.
2) False health status char 'A' instead of 'D' is emitted on the status
status info line for the meta/data device tuple in this metadata device
failure case.
3) If the metadata device is accessible when passed into the constructor
but the data device (partially) isn't, that leg may be set faulty by the
raid personality on access to the (partially) unavailable leg. Restore
tried in a second raid device resume on such failed leg (status char 'D')
fails after the (partial) leg returned.
Fixes for aforementioned failure scenarios:
- don't release passed in devices in the constructor thus allowing the
status table line to e.g. contain '254:4 254:5' rather than '- -'
- emit device status char 'D' rather than 'A' for the device tuple
with the failed metadata device on the status info line
- when attempting to restore faulty devices in a second resume, allow the
device hot remove function to succeed by setting the device to not in-sync
In case userspace intentionally passes '- -' into the constructor to avoid that
device tuple (e.g. to split off a raid1 leg temporarily for later re-addition),
the status table line will correctly show '- -' and the status info line will
provide a '-' device health character for the non-defined device tuple.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
write-back cache in degraded mode introduces corner cases to the array.
Although we try to cover all these corner cases, it is safer to just
disable write-back cache when the array is in degraded mode.
In this patch, we disable writeback cache for degraded mode:
1. On device failure, if the array enters degraded mode, raid5_error()
will submit async job r5c_disable_writeback_async to disable
writeback;
2. In r5c_journal_mode_store(), it is invalid to enable writeback in
degraded mode;
3. In r5c_try_caching_write(), stripes with s->failed>0 will be handled
in write-through mode.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Write back cache requires a complex RMW mechanism, where old data is
read into dev->orig_page for prexor, and then xor is done with
dev->page. This logic is already implemented in the write path.
However, current read path is not awared of this requirement. When
the array is optimal, the RMW is not required, as the data are
read from raid disks. However, when the target stripe is degraded,
complex RMW is required to generate right data.
To keep read path as clean as possible, we handle read path by
flushing degraded, in-journal stripes before processing reads to
missing dev.
Specifically, when there is read requests to a degraded stripe
with data in journal, handle_stripe_fill() calls
r5c_make_stripe_write_out() and exits. Then handle_stripe_dirtying()
will do the complex RMW and flush the stripe to RAID disks. After
that, read requests are handled.
There is one more corner case when there is non-overwrite bio for
the missing (or out of sync) dev. handle_stripe_dirtying() will not
be able to process the non-overwrite bios without constructing the
data in handle_stripe_fill(). This is fixed by delaying non-overwrite
bios in handle_stripe_dirtying(). So handle_stripe_fill() works on
these bios after the stripe is flushed to raid disks.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
For safer operation, all arrays start in write-through mode, which has been
better tested and is more mature. And actually the write-through/write-mode
isn't persistent after array restarted, so we always start array in
write-through mode. However, if recovery found data-only stripes before the
shutdown (from previous write-back mode), it is not safe to start the array in
write-through mode, as write-through mode can not handle stripes with data in
write-back cache. To solve this problem, we flush all data-only stripes in
r5l_recovery_log(). When r5l_recovery_log() returns, the array starts with
empty cache in write-through mode.
This logic is implemented in r5c_recovery_flush_data_only_stripes():
1. enable write back cache
2. flush all stripes
3. wake up conf->mddev->thread
4. wait for all stripes get flushed (reuse wait_for_quiescent)
5. disable write back cache
The wait in 4 will be waked up in release_inactive_stripe_list()
when conf->active_stripes reaches 0.
It is safe to wake up mddev->thread here because all the resource
required for the thread has been initialized.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
With write back cache, we use orig_page to do prexor. This patch
makes sure we read data into orig_page for it.
Flag R5_OrigPageUPTDODATE is added to show whether orig_page
has the latest data from raid disk.
We introduce a helper function uptodate_for_rmw() to simplify
the a couple conditions in handle_stripe_dirtying().
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
This is a nasty interface and setting the state of a foreign task must
not be done. As of the following commit:
be628be095 ("bcache: Make gc wakeup sane, remove set_task_state()")
... everyone in the kernel calls set_task_state() with current, allowing
the helper to be removed.
However, as the comment indicates, it is still around for those archs
where computing current is more expensive than using a pointer, at least
in theory. An important arch that is affected is arm64, however this has
been addressed now [1] and performance is up to par making no difference
with either calls.
Of all the callers, if any, it's the locking bits that would care most
about this -- ie: we end up passing a tsk pointer to a lot of the lock
slowpath, and setting ->state on that. The following numbers are based
on two tests: a custom ad-hoc microbenchmark that just measures
latencies (for ~65 million calls) between get_task_state() vs
get_current_state().
Secondly for a higher overview, an unlink microbenchmark was used,
which pounds on a single file with open, close,unlink combos with
increasing thread counts (up to 4x ncpus). While the workload is quite
unrealistic, it does contend a lot on the inode mutex or now rwsem.
[1] https://lkml.kernel.org/r/1483468021-8237-1-git-send-email-mark.rutland@arm.com
== 1. x86-64 ==
Avg runtime set_task_state(): 601 msecs
Avg runtime set_current_state(): 552 msecs
vanilla dirty
Hmean unlink1-processes-2 36089.26 ( 0.00%) 38977.33 ( 8.00%)
Hmean unlink1-processes-5 28555.01 ( 0.00%) 29832.55 ( 4.28%)
Hmean unlink1-processes-8 37323.75 ( 0.00%) 44974.57 ( 20.50%)
Hmean unlink1-processes-12 43571.88 ( 0.00%) 44283.01 ( 1.63%)
Hmean unlink1-processes-21 34431.52 ( 0.00%) 38284.45 ( 11.19%)
Hmean unlink1-processes-30 34813.26 ( 0.00%) 37975.17 ( 9.08%)
Hmean unlink1-processes-48 37048.90 ( 0.00%) 39862.78 ( 7.59%)
Hmean unlink1-processes-79 35630.01 ( 0.00%) 36855.30 ( 3.44%)
Hmean unlink1-processes-110 36115.85 ( 0.00%) 39843.91 ( 10.32%)
Hmean unlink1-processes-141 32546.96 ( 0.00%) 35418.52 ( 8.82%)
Hmean unlink1-processes-172 34674.79 ( 0.00%) 36899.21 ( 6.42%)
Hmean unlink1-processes-203 37303.11 ( 0.00%) 36393.04 ( -2.44%)
Hmean unlink1-processes-224 35712.13 ( 0.00%) 36685.96 ( 2.73%)
== 2. ppc64le ==
Avg runtime set_task_state(): 938 msecs
Avg runtime set_current_state: 940 msecs
vanilla dirty
Hmean unlink1-processes-2 19269.19 ( 0.00%) 30704.50 ( 59.35%)
Hmean unlink1-processes-5 20106.15 ( 0.00%) 21804.15 ( 8.45%)
Hmean unlink1-processes-8 17496.97 ( 0.00%) 17243.28 ( -1.45%)
Hmean unlink1-processes-12 14224.15 ( 0.00%) 17240.21 ( 21.20%)
Hmean unlink1-processes-21 14155.66 ( 0.00%) 15681.23 ( 10.78%)
Hmean unlink1-processes-30 14450.70 ( 0.00%) 15995.83 ( 10.69%)
Hmean unlink1-processes-48 16945.57 ( 0.00%) 16370.42 ( -3.39%)
Hmean unlink1-processes-79 15788.39 ( 0.00%) 14639.27 ( -7.28%)
Hmean unlink1-processes-110 14268.48 ( 0.00%) 14377.40 ( 0.76%)
Hmean unlink1-processes-141 14023.65 ( 0.00%) 16271.69 ( 16.03%)
Hmean unlink1-processes-172 13417.62 ( 0.00%) 16067.55 ( 19.75%)
Hmean unlink1-processes-203 15293.08 ( 0.00%) 15440.40 ( 0.96%)
Hmean unlink1-processes-234 13719.32 ( 0.00%) 16190.74 ( 18.01%)
Hmean unlink1-processes-265 16400.97 ( 0.00%) 16115.22 ( -1.74%)
Hmean unlink1-processes-296 14388.60 ( 0.00%) 16216.13 ( 12.70%)
Hmean unlink1-processes-320 15771.85 ( 0.00%) 15905.96 ( 0.85%)
x86-64 (known to be fast for get_current()/this_cpu_read_stable() caching)
and ppc64 (with paca) show similar improvements in the unlink microbenches.
The small delta for ppc64 (2ms), does not represent the gains on the unlink
runs. In the case of x86, there was a decent amount of variation in the
latency runs, but always within a 20 to 50ms increase), ppc was more constant.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Cc: mark.rutland@arm.com
Link: http://lkml.kernel.org/r/1483479794-14013-5-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This fixes a build error on certain architectures, such as ppc64.
Fixes: 6995f0b247e("md: takeover should clear unrelated bits")
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Commit 6995f0b (md: takeover should clear unrelated bits) clear
unrelated bits, but it's quite fragile. To avoid error in the future,
define a macro for unsupported mddev flags for each raid type and use it
to clear unsupported mddev flags. This should be less error-prone.
Suggested-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Trivial fix to spelling mistake "recoverying" to "recovering" in
pr_dbg message.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Shaohua Li <shli@fb.com>
r5l_load_log() calls functions that requires a proper conf->log,
for example, r5c_is_writeback(). Therefore, we should set
conf->log before calling r5l_load_log(). If r5l_load_log() fails,
conf->log is set back to NULL.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
We only need to update sh->log_start at the end of recovery,
which is r5c_recovery_rewrite_data_only_stripes(), so it is not
necessary to set it before that. In this patch, log_start is
removed from r5c_recovery_alloc_stripe().
After updating all sh->log_start, rewrite_data_only_stripes()
also updates log->next_checkpoints to the last sh->log_start.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The write-through mode has been returned in front of the function,
do not need to do it again.
Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Refactor raid10_make_request into seperate read and write functions to
clean up the code.
Shaohua: add the recovery check back to read path
Signed-off-by: Robert LeBlanc <robert@leblancnet.us>
Signed-off-by: Shaohua Li <shli@fb.com>
Refactor raid1_make_request to make read and write code in their own
functions to clean up the code.
Signed-off-by: Robert LeBlanc <robert@leblancnet.us>
Signed-off-by: Shaohua Li <shli@fb.com>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__bitwise__ used to mean "yes, please enable sparse checks
unconditionally", but now that we dropped __CHECK_ENDIAN__
__bitwise is exactly the same.
There aren't many users, replace it by __bitwise everywhere.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Stefan Schmidt <stefan@osg.samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Akced-by: Lee Duncan <lduncan@suse.com>
. some locking improvements in DM bufio
. add Kconfig option to disable the DM block manager's extra locking
which mainly serves as a developer tool
. a few bug fixes to DM's persistent-data
. a couple changes to prepare for multipage biovec support in the block
layer
. various improvements and cleanups in the DM core, DM cache, DM raid
and DM crypt
. add ability to have DM crypt use keys from the kernel key retention
service
. add a new "error_writes" feature to the DM flakey target, reads are
left unchanged in this mode
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Merge tag 'dm-4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper updates from Mike Snitzer:
- various fixes and improvements to request-based DM and DM multipath
- some locking improvements in DM bufio
- add Kconfig option to disable the DM block manager's extra locking
which mainly serves as a developer tool
- a few bug fixes to DM's persistent-data
- a couple changes to prepare for multipage biovec support in the block
layer
- various improvements and cleanups in the DM core, DM cache, DM raid
and DM crypt
- add ability to have DM crypt use keys from the kernel key retention
service
- add a new "error_writes" feature to the DM flakey target, reads are
left unchanged in this mode
* tag 'dm-4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (40 commits)
dm flakey: introduce "error_writes" feature
dm cache policy smq: use hash_32() instead of hash_32_generic()
dm crypt: reject key strings containing whitespace chars
dm space map: always set ev if sm_ll_mutate() succeeds
dm space map metadata: skip useless memcpy in metadata_ll_init_index()
dm space map metadata: fix 'struct sm_metadata' leak on failed create
Documentation: dm raid: define data_offset status field
dm raid: fix discard support regression
dm raid: don't allow "write behind" with raid4/5/6
dm mpath: use hw_handler_params if attached hw_handler is same as requested
dm crypt: add ability to use keys from the kernel key retention service
dm array: remove a dead assignment in populate_ablock_with_values()
dm ioctl: use offsetof() instead of open-coding it
dm rq: simplify use_blk_mq initialization
dm: use blk_set_queue_dying() in __dm_destroy()
dm bufio: drop the lock when doing GFP_NOIO allocation
dm bufio: don't take the lock in dm_bufio_shrink_count
dm bufio: avoid sleeping while holding the dm_bufio lock
dm table: simplify dm_table_determine_type()
dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device
...
Recent dm-flakey fixes, to have reads error out during the "down"
interval, made it so that the previous read behaviour is no longer
available.
It is useful to have reads complete like normal but have writes error
out, so make it possible again with a new "error_writes" feature.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Pull block layer updates from Jens Axboe:
"This is the main block pull request this series. Contrary to previous
release, I've kept the core and driver changes in the same branch. We
always ended up having dependencies between the two for obvious
reasons, so makes more sense to keep them together. That said, I'll
probably try and keep more topical branches going forward, especially
for cycles that end up being as busy as this one.
The major parts of this pull request is:
- Improved support for O_DIRECT on block devices, with a small
private implementation instead of using the pig that is
fs/direct-io.c. From Christoph.
- Request completion tracking in a scalable fashion. This is utilized
by two components in this pull, the new hybrid polling and the
writeback queue throttling code.
- Improved support for polling with O_DIRECT, adding a hybrid mode
that combines pure polling with an initial sleep. From me.
- Support for automatic throttling of writeback queues on the block
side. This uses feedback from the device completion latencies to
scale the queue on the block side up or down. From me.
- Support from SMR drives in the block layer and for SD. From Hannes
and Shaun.
- Multi-connection support for nbd. From Josef.
- Cleanup of request and bio flags, so we have a clear split between
which are bio (or rq) private, and which ones are shared. From
Christoph.
- A set of patches from Bart, that improve how we handle queue
stopping and starting in blk-mq.
- Support for WRITE_ZEROES from Chaitanya.
- Lightnvm updates from Javier/Matias.
- Supoort for FC for the nvme-over-fabrics code. From James Smart.
- A bunch of fixes from a whole slew of people, too many to name
here"
* 'for-4.10/block' of git://git.kernel.dk/linux-block: (182 commits)
blk-stat: fix a few cases of missing batch flushing
blk-flush: run the queue when inserting blk-mq flush
elevator: make the rqhash helpers exported
blk-mq: abstract out blk_mq_dispatch_rq_list() helper
blk-mq: add blk_mq_start_stopped_hw_queue()
block: improve handling of the magic discard payload
blk-wbt: don't throttle discard or write zeroes
nbd: use dev_err_ratelimited in io path
nbd: reset the setup task for NBD_CLEAR_SOCK
nvme-fabrics: Add FC LLDD loopback driver to test FC-NVME
nvme-fabrics: Add target support for FC transport
nvme-fabrics: Add host support for FC transport
nvme-fabrics: Add FC transport LLDD api definitions
nvme-fabrics: Add FC transport FC-NVME definitions
nvme-fabrics: Add FC transport error codes to nvme.h
Add type 0x28 NVME type code to scsi fc headers
nvme-fabrics: patch target code in prep for FC transport support
nvme-fabrics: set sqe.command_id in core not transports
parser: add u64 number parser
nvme-rdma: align to generic ib_event logging helper
...
The mddev->flags are used for different purposes. There are a lot of
places we check/change the flags without masking unrelated flags, we
could check/change unrelated flags. These usage are most for superblock
write, so spearate superblock related flags. This should make the code
clearer and also fix real bugs.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
When we change level from raid1 to raid5, the MD_FAILFAST_SUPPORTED bit
will be accidentally set, but raid5 doesn't support it. The same is true
for the MD_HAS_JOURNAL bit.
Fix: 46533ff (md: Use REQ_FAILFAST_* on metadata writes where appropriate)
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Unfortunately key_string may theoretically contain whitespace even after
it's processed by dm_split_args(). The reason for this is DM core
supports escaping of almost all chars including any whitespace.
If userspace passes a key to the kernel in format ":32:logon:my_prefix:my\ key"
dm-crypt will look up key "my_prefix:my key" in kernel keyring service.
So far everything's fine.
Unfortunately if userspace later calls DM_TABLE_STATUS ioctl, it will not
receive back expected ":32:logon:my_prefix:my\ key" but the unescaped version
instead. Also userpace (most notably cryptsetup) is not ready to parse
single target argument containing (even escaped) whitespace chars and any
whitespace is simply taken as delimiter of another argument.
This effect is mitigated by the fact libdevmapper curently performs
double escaping of '\' char. Any user input in format "x\ x" is
transformed into "x\\ x" before being passed to the kernel. Nonetheless
dm-crypt may be used without libdevmapper. Therefore the near-term
solution to this is to reject any key string containing whitespace.
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If no block was allocated or freed, sm_ll_mutate() wasn't setting
*ev, leaving the variable unitialized. sm_ll_insert(),
sm_disk_inc_block(), and sm_disk_new_block() all check ev to see
if there was an allocation event in sm_ll_mutate(), possibly
reading unitialized data.
If no allocation event occured, sm_ll_mutate() should set *ev
to SM_NONE.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When metadata_ll_init_index() is called by sm_ll_new_metadata(),
ll->mi_le hasn't been initialized yet. So, when
metadata_ll_init_index() copies the contents of ll->mi_le into the
newly allocated bitmap_root, it is just copying garbage. ll->mi_le
will be allocated later in sm_ll_extend() and copied into the
bitmap_root, in sm_ll_commit().
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
In dm_sm_metadata_create() we temporarily change the dm_space_map
operations from 'ops' (whose .destroy function deallocates the
sm_metadata) to 'bootstrap_ops' (whose .destroy function doesn't).
If dm_sm_metadata_create() fails in sm_ll_new_metadata() or
sm_ll_extend(), it exits back to dm_tm_create_internal(), which calls
dm_sm_destroy() with the intention of freeing the sm_metadata, but it
doesn't (because the dm_space_map operations is still set to
'bootstrap_ops').
Fix this by setting the dm_space_map operations back to 'ops' if
dm_sm_metadata_create() fails when it is set to 'bootstrap_ops'.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Commit ecbfb9f118 ("dm raid: add raid level takeover support") moved the
configure_discard_support() call from raid_ctr() to raid_preresume().
Enabling/disabling discard _must_ happen during table load (through the
.ctr hook). Fix this regression by moving the
configure_discard_support() call back to raid_ctr().
Fixes: ecbfb9f118 ("dm raid: add raid level takeover support")
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Remove CTR_FLAG_MAX_WRITE_BEHIND from raid4/5/6's valid ctr flags.
Only the md raid1 personality supports setting a maximum number
of "write behind" write IOs on any legs set to "write mostly".
"write mostly" enhances throughput with slow links/disks.
Technically the "write behind" value is a write intent bitmap
property only being respected by the raid1 personality. It allows a
maximum number of "write behind" writes to any "write mostly" raid1
mirror legs to be delayed and avoids reads from such legs.
No other MD personalities supported via dm-raid make use of "write
behind", thus setting this property is superfluous; it wouldn't cause
harm but it is correct to reject it.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Let the requested m->hw_handler_params be used if the attached hardware
handler is the same handler as requested with m->hw_handler_name.
Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The kernel key service is a generic way to store keys for the use of
other subsystems. Currently there is no way to use kernel keys in dm-crypt.
This patch aims to fix that. Instead of key userspace may pass a key
description with preceding ':'. So message that constructs encryption
mapping now looks like this:
<cipher> [<key>|:<key_string>] <iv_offset> <dev_path> <start> [<#opt_params> <opt_params>]
where <key_string> is in format: <key_size>:<key_type>:<key_description>
Currently we only support two elementary key types: 'user' and 'logon'.
Keys may be loaded in dm-crypt either via <key_string> or using
classical method and pass the key in hex representation directly.
dm-crypt device initialised with a key passed in hex representation may be
replaced with key passed in key_string format and vice versa.
(Based on original work by Andrey Ryabinin)
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
A value is assigned to 'nr_entries' but is never used, remove it.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Subtracting sizes is a fragile approach because the result is only
correct if the compiler has not added any padding at the end of the
structure. Hence use offsetof() instead of size subtraction. An
additional advantage of offsetof() is that it makes the intent more
clear.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Use a single statement to declare and initialize 'use_blk_mq' instead
of two statements.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
After QUEUE_FLAG_DYING has been set any code that is waiting in
get_request() should be woken up. But to get this behaviour
blk_set_queue_dying() must be used instead of only setting
QUEUE_FLAG_DYING.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If the first allocation attempt using GFP_NOWAIT fails, drop the lock
and retry using GFP_NOIO allocation (lock is dropped because the
allocation can take some time).
Note that we won't do GFP_NOIO allocation when we loop for the second
time, because the lock shouldn't be dropped between __wait_for_free_buffer
and __get_unclaimed_buffer.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
dm_bufio_shrink_count() is called from do_shrink_slab to find out how many
freeable objects are there. The reported value doesn't have to be precise,
so we don't need to take the dm-bufio lock.
Suggested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
We've seen in-field reports showing _lots_ (18 in one case, 41 in
another) of tasks all sitting there blocked on:
mutex_lock+0x4c/0x68
dm_bufio_shrink_count+0x38/0x78
shrink_slab.part.54.constprop.65+0x100/0x464
shrink_zone+0xa8/0x198
In the two cases analyzed, we see one task that looks like this:
Workqueue: kverityd verity_prefetch_io
__switch_to+0x9c/0xa8
__schedule+0x440/0x6d8
schedule+0x94/0xb4
schedule_timeout+0x204/0x27c
schedule_timeout_uninterruptible+0x44/0x50
wait_iff_congested+0x9c/0x1f0
shrink_inactive_list+0x3a0/0x4cc
shrink_lruvec+0x418/0x5cc
shrink_zone+0x88/0x198
try_to_free_pages+0x51c/0x588
__alloc_pages_nodemask+0x648/0xa88
__get_free_pages+0x34/0x7c
alloc_buffer+0xa4/0x144
__bufio_new+0x84/0x278
dm_bufio_prefetch+0x9c/0x154
verity_prefetch_io+0xe8/0x10c
process_one_work+0x240/0x424
worker_thread+0x2fc/0x424
kthread+0x10c/0x114
...and that looks to be the one holding the mutex.
The problem has been reproduced on fairly easily:
0. Be running Chrome OS w/ verity enabled on the root filesystem
1. Pick test patch: http://crosreview.com/412360
2. Install launchBalloons.sh and balloon.arm from
http://crbug.com/468342
...that's just a memory stress test app.
3. On a 4GB rk3399 machine, run
nice ./launchBalloons.sh 4 900 100000
...that tries to eat 4 * 900 MB of memory and keep accessing.
4. Login to the Chrome web browser and restore many tabs
With that, I've seen printouts like:
DOUG: long bufio 90758 ms
...and stack trace always show's we're in dm_bufio_prefetch().
The problem is that we try to allocate memory with GFP_NOIO while
we're holding the dm_bufio lock. Instead we should be using
GFP_NOWAIT. Using GFP_NOIO can cause us to sleep while holding the
lock and that causes the above problems.
The current behavior explained by David Rientjes:
It will still try reclaim initially because __GFP_WAIT (or
__GFP_KSWAPD_RECLAIM) is set by GFP_NOIO. This is the cause of
contention on dm_bufio_lock() that the thread holds. You want to
pass GFP_NOWAIT instead of GFP_NOIO to alloc_buffer() when holding a
mutex that can be contended by a concurrent slab shrinker (if
count_objects didn't use a trylock, this pattern would trivially
deadlock).
This change significantly increases responsiveness of the system while
in this state. It makes a real difference because it unblocks kswapd.
In the bug report analyzed, kswapd was hung:
kswapd0 D ffffffc000204fd8 0 72 2 0x00000000
Call trace:
[<ffffffc000204fd8>] __switch_to+0x9c/0xa8
[<ffffffc00090b794>] __schedule+0x440/0x6d8
[<ffffffc00090bac0>] schedule+0x94/0xb4
[<ffffffc00090be44>] schedule_preempt_disabled+0x28/0x44
[<ffffffc00090d900>] __mutex_lock_slowpath+0x120/0x1ac
[<ffffffc00090d9d8>] mutex_lock+0x4c/0x68
[<ffffffc000708e7c>] dm_bufio_shrink_count+0x38/0x78
[<ffffffc00030b268>] shrink_slab.part.54.constprop.65+0x100/0x464
[<ffffffc00030dbd8>] shrink_zone+0xa8/0x198
[<ffffffc00030e578>] balance_pgdat+0x328/0x508
[<ffffffc00030eb7c>] kswapd+0x424/0x51c
[<ffffffc00023f06c>] kthread+0x10c/0x114
[<ffffffc000203dd0>] ret_from_fork+0x10/0x40
By unblocking kswapd memory pressure should be reduced.
Suggested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Use a single loop instead of two loops to determine whether or not
all_blk_mq has to be set.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When dm_table_set_type() is used by a target to establish a DM table's
type (e.g. DM_TYPE_MQ_REQUEST_BASED in the case of DM multipath) the
DM core must go on to verify that the devices in the table are
compatible with the established type.
Fixes: e83068a5 ("dm mpath: add optional "queue_mode" feature")
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
An earlier DM multipath table could have been build ontop of underlying
devices that were all using blk-mq. In that case, if that active
multipath table is replaced with an empty DM multipath table (that
reflects all paths have failed) then it is important that the
'all_blk_mq' state of the active table is transfered to the new empty DM
table. Otherwise dm-rq.c:dm_old_prep_tio() will incorrectly clone a
request that isn't needed by the DM multipath target when it is to issue
IO to an underlying blk-mq device.
Fixes: e83068a5 ("dm mpath: add optional "queue_mode" feature")
Cc: stable@vger.kernel.org # 4.8+
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Currently, we increase journal entry seq by 10 after recovery.
However, this is not sufficient in the following case.
After crash the journal looks like
| seq+0 | +1 | +2 | +3 | +4 | +5 | +6 | +7 | ... | +11 | +12 |
If +1 is not valid, we dropped all entries from +1 to +12; and
write seq+10:
| seq+0 | +10 | +2 | +3 | +4 | +5 | +6 | +7 | ... | +11 | +12 |
However, if we write a big journal entry with seq+11, it will
connect with some stale journal entry:
| seq+0 | +10 | +11 | +12 |
To reduce the risk of this issue, we increase seq by 10000 instead.
Shaohua: use 10000 instead of 1000. The risk should be very unlikely. The total
stripe cache size is less than 2k typically, and several stripes can fit into
one meta data block. So the total inflight meta data blocks would be quite
small, which means the the total sequence number used should be quite small.
The 10000 sequence number increase should be far more than safe.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
r5l_recovery_create_empty_meta_block() creates crc for the empty
metablock. After the metablock is updated, we need clear the
checksum before recalculate it.
Shaohua: moved checksum calculation out of
r5l_recovery_create_empty_meta_block. We should calculate it after all fields
are updated.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
When create the super-block information, We do not need to do this
recovery stage, only need to initialize some variables.
Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
md_open() gets a counted reference on an mddev using mddev_find().
If it ends up returning an error, it must drop this reference.
There are two error paths where the reference is not dropped.
One only happens if the process is signalled and an awkward time,
which is quite unlikely.
The other was introduced recently in commit af8d8e6f0.
Change the code to ensure the drop the reference when returning an error,
and make it harded to re-introduce this sort of bug in the future.
Reported-by: Marc Smith <marc.smith@mcc.edu>
Fixes: af8d8e6f03 ("md: changes for MD_STILL_CLOSED flag")
Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
We should update log state after we did a log recovery, current completion
may get wrong log state since log->log_start wasn't initalized until we
called r5l_recovery_log.
At log recovery stage, no lock needed as there is no race conditon.
next_checkpoint field will be initialized in r5l_recovery_log too.
Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
When recovery is complete, we write an empty block and record his
position first, then make the data-only stripes rewritten done,
the location of the empty block as the last checkpoint position
to write into the super block. And we should update last_checkpoint
to this empty block position.
------------------------------------------------------------------
| old log | empty block | data only stripes | invalid log |
------------------------------------------------------------------
^ ^ ^
| |- log->last_checkpoint |- log->log_start
| |- log->last_cp_seq |- log->next_checkpoint
|- log->seq=n |- log->seq=10+n
At the same time, if there is no data-only stripes, this scene may appear,
| meta1 | meta2 | meta3 |
meta 1 is valid, meta 2 is invalid. meta 3 could be valid. so we should
The solution is we create a new meta in meta2 with its seq == meta1's
seq + 10 and let superblock points to meta2.
Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Reviewed-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
With writeback cache, we define log space critical as
free_space < 2 * reclaim_required_space
So the deassert of R5C_LOG_CRITICAL could happen when
1. free_space increases
2. reclaim_required_space decreases
Currently, run_no_space_stripes() is called when 1 happens, but
not (always) when 2 happens.
With this patch, run_no_space_stripes() is call when
R5C_LOG_CRITICAL is cleared.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Current implementation employ 16bit counter of active stripes in lower
bits of bio->bi_phys_segments. If request is big enough to overflow
this counter bio will be completed and freed too early.
Fortunately this not happens in default configuration because several
other limits prevent that: stripe_cache_size * nr_disks effectively
limits count of active stripes. And small max_sectors_kb at lower
disks prevent that during normal read/write operations.
Overflow easily happens in discard if it's enabled by module parameter
"devices_handle_discard_safely" and stripe_cache_size is set big enough.
This patch limits requests size with 256Mb - 8Kb to prevent overflows.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Shaohua Li <shli@kernel.org>
Cc: Neil Brown <neilb@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Shaohua Li <shli@fb.com>
R5c_make_stripe_write_out has set this flag, do not need to set again.
Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
If we released the 'stripe_head' in r5c_recovery_flush_log,
ctx->cached_list will both release the data-parity stripes and
data-only stripes, which will become empty.
And we also need to use the data-only stripes in
r5c_recovery_rewrite_data_only_stripes, so we should wait util rewrite
data-only stripes is done before releasing them.
Reviewed-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
'write_pos' must be protected with 'r5l_ring_add', or it may overflow
Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
The function parameter 'recovery_list' is not used in
body, we can delete it
Signed-off-by: JackieLiu <liuyun01@kylinos.cn>
Reviewed-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
r5c_recovery_load_one_stripe should not set STRIPE_R5C_PARTIAL_STRIPE flag,as
the data-only stripe may be STRIPE_R5C_FULL_STRIPE stripe. The state machine
would release the stripe later and add it into neither r5c_cached_full_stripes
list or r5c_cached_partial_stripes list and set correct flag.
Reviewed-by: JackieLiu <liuyun01@kylinos.cn>
Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
New stripe that was just allocated has no STRIPE_R5C_CACHING state too,
add this check condition could avoid unnecessary replaying for empty stripe.
r5l_recovery_replay_one_stripe would reset stripe for any case, delete it
to make code more clean.
Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Shaohua Li <shli@fb.com>
We need to re-enable the IRQs here before returning.
Fixes: a39f7afde3 ("md/r5cache: write-out phase and reclaim support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Shaohua Li <shli@fb.com>
RMW of r5c write back cache uses an extra page to store old data for
prexor. handle_stripe_dirtying() allocates this page by calling
alloc_page(). However, alloc_page() may fail.
To handle alloc_page() failures, this patch adds an extra page to
disk_info. When alloc_page fails, handle_stripe() trys to use these
pages. When these pages are used by other stripe (R5C_EXTRA_PAGE_IN_USE),
the stripe is added to delayed_list.
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
__md_stop_writes currently doesn't stop raid5-cache reclaim thread. It's
possible the reclaim thread is still running and doing write, which
doesn't match what __md_stop_writes should do. The extra ->quiesce()
call should not harm any raid types. For raid5-cache, this will
guarantee we reclaim all caches before we update superblock.
Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Cc: Song Liu <songliubraving@fb.com>
Mike Snitzer