Commit Graph

797316 Commits

Author SHA1 Message Date
Jens Axboe ea86ea2cdc sbitmap: ammortize cost of clearing bits
sbitmap maintains a set of words that we use to set and clear bits, with
each bit representing a tag for blk-mq. Even though we spread the bits
out and maintain a hint cache, one particular bit allocated will end up
being cleared in the exact same spot.

This introduces batched clearing of bits. Instead of clearing a given
bit, the same bit is set in a cleared/free mask instead. If we fail
allocating a bit from a given word, then we check the free mask, and
batch move those cleared bits at that time. This trades 64 atomic bitops
for 2 cmpxchg().

In a threaded poll test case, half the overhead of getting and clearing
tags is removed with this change. On another poll test case with a
single thread, performance is unchanged.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-30 14:47:45 -07:00
Christoph Hellwig 531724abc3 block: avoid extra bio reference for async O_DIRECT
The bio referencing has a trick that doesn't do any actual atomic
inc/dec on the reference count until we have to elevator to > 1. For the
async IO O_DIRECT case, we can't use the simple DIO variants, so we use
__blkdev_direct_IO(). It always grabs an extra reference to the bio
after allocation, which means we then enter the slower path of actually
having to do atomic_inc/dec on the count.

We don't need to do that for the async case, unless we end up going
multi-bio, in which case we're already doing huge amounts of IO. For the
smaller IO case (< BIO_MAX_PAGES), we can do without the extra ref.

Based on an earlier patch (and commit log) from Jens Axboe.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-30 08:28:51 -07:00
Jens Axboe 27fae429ac sbitmap: don't loop for find_next_zero_bit() for !round_robin
If we aren't forced to do round robin tag allocation, just use the
allocation hint to find the index for the tag word, don't use it for the
offset inside the word. This avoids a potential extra round trip in the
bit looping, and since we're fetching this cacheline, we may as well
check the whole word from the start.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 13:58:34 -07:00
Jens Axboe b2c5d16b72 blk-mq: use plug for devices that implement ->commits_rqs()
If we have that hook, we know the driver handles bd->last == true in
a smart fashion. If it does, even for multiple hardware queues, it's
a good idea to flush batches of requests to the device, if we have
batches of requests from the submitter.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 10:12:37 -07:00
Jens Axboe be94f058f2 blk-mq: use bd->last == true for list inserts
If we are issuing a list of requests, we know if we're at the last one.
If we fail issuing, ensure that we call ->commits_rqs() to flush any
potential previous requests.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 10:12:32 -07:00
Jens Axboe 80ff2040ac ataflop: implement mq_ops->commit_rqs() hook
We need this for blk-mq to kick things into gear, if we told it that
we had more IO coming, but then failed to deliver on that promise.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 10:12:27 -07:00
Jens Axboe 944e7c8796 virtio_blk: implement mq_ops->commit_rqs() hook
We need this for blk-mq to kick things into gear, if we told it that
we had more IO coming, but then failed to deliver on that promise.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 10:12:22 -07:00
Jens Axboe 04f3eafda6 nvme: implement mq_ops->commit_rqs() hook
Split the command submission and the SQ doorbell ring, and add the
doorbell ring as our ->commit_rqs() hook. This allows a list of
requests to be issued, with nvme only writing the SQ update when
it's necessary. This is more efficient if we have lists of requests
to issue, particularly on virtualized hardware, where writing the
SQ doorbell is more expensive than on real hardware. For those cases,
performance increases of 2-3x have been observed.

The use case for this is plugged IO, where blk-mq flushes a batch of
requests at the time.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 10:12:07 -07:00
Jens Axboe d666ba98f8 blk-mq: add mq_ops->commit_rqs()
blk-mq passes information to the hardware about any given request being
the last that we will issue in this sequence. The point is that hardware
can defer costly doorbell type writes to the last request. But if we run
into errors issuing a sequence of requests, we may never send the request
with bd->last == true set. For that case, we need a hook that tells the
hardware that nothing else is coming right now.

For failures returned by the drivers ->queue_rq() hook, the driver is
responsible for flushing pending requests, if it uses bd->last to
optimize that part. This works like before, no changes there.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 10:11:56 -07:00
Jens Axboe ce5b009cff block: improve logic around when to sort a plug list
Only do it if we have requests for multiple queues in the same
plug.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 10:11:45 -07:00
Dan Carpenter 4e6db0f21c blk-mq: Add a NULL check in blk_mq_free_map_and_requests()
I recently found some code which called blk_mq_free_map_and_requests()
with a NULL set->tags pointer.  I fixed the caller, but it seems like a
good idea to add a NULL check here as well.  Now we can call:

	blk_mq_free_tag_set(set);
	blk_mq_free_tag_set(set);

twice in a row and it's harmless.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 08:16:08 -07:00
Dan Carpenter 49379e6d1e ataflop: fix error handling in atari_floppy_init()
Smatch complains that there is an off by one if the allocation fails in:

	DMABuffer = atari_stram_alloc(BUFFER_SIZE+512, "ataflop");

In that situation, "i" would be point to one element beyond the end of
the unit[] array.

There is a second bug because the error handling calls
blk_mq_free_tag_set(&unit[i].tag_set); regardless of whether
"disk->queue" is NULL or non-NULL.  So if blk_mq_init_sq_queue() fails,
then that means unit[i].tag_set->tags is NULL and it leads to an Oops.

It's easiest to call put_disk() before the goto to clean up the partial
iteration.  Then the earlier unit[] elements are fully allocated so we
can remove the checks whether "disk->queue" is NULL and the code is
simpler.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 08:16:06 -07:00
Weiping Zhang 65cd1d13b8 block: add io timeout to sysfs
Give a interface to adjust io timeout(ms) by device.

Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-28 09:08:28 -07:00
Yufen Yu 94a2c3a32b block: use rcu_work instead of call_rcu to avoid sleep in softirq
We recently got a stack by syzkaller like this:

BUG: sleeping function called from invalid context at mm/slab.h:361
in_atomic(): 1, irqs_disabled(): 0, pid: 6644, name: blkid
INFO: lockdep is turned off.
CPU: 1 PID: 6644 Comm: blkid Not tainted 4.4.163-514.55.6.9.x86_64+ #76
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
 0000000000000000 5ba6a6b879e50c00 ffff8801f6b07b10 ffffffff81cb2194
 0000000041b58ab3 ffffffff833c7745 ffffffff81cb2080 5ba6a6b879e50c00
 0000000000000000 0000000000000001 0000000000000004 0000000000000000
Call Trace:
 <IRQ>  [<ffffffff81cb2194>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ>  [<ffffffff81cb2194>] dump_stack+0x114/0x1a0 lib/dump_stack.c:51
 [<ffffffff8129a981>] ___might_sleep+0x291/0x490 kernel/sched/core.c:7675
 [<ffffffff8129ac33>] __might_sleep+0xb3/0x270 kernel/sched/core.c:7637
 [<ffffffff81794c13>] slab_pre_alloc_hook mm/slab.h:361 [inline]
 [<ffffffff81794c13>] slab_alloc_node mm/slub.c:2610 [inline]
 [<ffffffff81794c13>] slab_alloc mm/slub.c:2692 [inline]
 [<ffffffff81794c13>] kmem_cache_alloc_trace+0x2c3/0x5c0 mm/slub.c:2709
 [<ffffffff81cbe9a7>] kmalloc include/linux/slab.h:479 [inline]
 [<ffffffff81cbe9a7>] kzalloc include/linux/slab.h:623 [inline]
 [<ffffffff81cbe9a7>] kobject_uevent_env+0x2c7/0x1150 lib/kobject_uevent.c:227
 [<ffffffff81cbf84f>] kobject_uevent+0x1f/0x30 lib/kobject_uevent.c:374
 [<ffffffff81cbb5b9>] kobject_cleanup lib/kobject.c:633 [inline]
 [<ffffffff81cbb5b9>] kobject_release+0x229/0x440 lib/kobject.c:675
 [<ffffffff81cbb0a2>] kref_sub include/linux/kref.h:73 [inline]
 [<ffffffff81cbb0a2>] kref_put include/linux/kref.h:98 [inline]
 [<ffffffff81cbb0a2>] kobject_put+0x72/0xd0 lib/kobject.c:692
 [<ffffffff8216f095>] put_device+0x25/0x30 drivers/base/core.c:1237
 [<ffffffff81c4cc34>] delete_partition_rcu_cb+0x1d4/0x2f0 block/partition-generic.c:232
 [<ffffffff813c08bc>] __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 [<ffffffff813c08bc>] rcu_do_batch kernel/rcu/tree.c:2705 [inline]
 [<ffffffff813c08bc>] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline]
 [<ffffffff813c08bc>] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline]
 [<ffffffff813c08bc>] rcu_process_callbacks+0x59c/0x1c70 kernel/rcu/tree.c:2957
 [<ffffffff8120f509>] __do_softirq+0x299/0xe20 kernel/softirq.c:273
 [<ffffffff81210496>] invoke_softirq kernel/softirq.c:350 [inline]
 [<ffffffff81210496>] irq_exit+0x216/0x2c0 kernel/softirq.c:391
 [<ffffffff82c2cd7b>] exiting_irq arch/x86/include/asm/apic.h:652 [inline]
 [<ffffffff82c2cd7b>] smp_apic_timer_interrupt+0x8b/0xc0 arch/x86/kernel/apic/apic.c:926
 [<ffffffff82c2bc25>] apic_timer_interrupt+0xa5/0xb0 arch/x86/entry/entry_64.S:746
 <EOI>  [<ffffffff814cbf40>] ? audit_kill_trees+0x180/0x180
 [<ffffffff8187d2f7>] fd_install+0x57/0x80 fs/file.c:626
 [<ffffffff8180989e>] do_sys_open+0x45e/0x550 fs/open.c:1043
 [<ffffffff818099c2>] SYSC_open fs/open.c:1055 [inline]
 [<ffffffff818099c2>] SyS_open+0x32/0x40 fs/open.c:1050
 [<ffffffff82c299e1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

In softirq context, we call rcu callback function delete_partition_rcu_cb(),
which may allocate memory by kzalloc with GFP_KERNEL flag. If the
allocation cannot be satisfied, it may sleep. However, That is not allowed
in softirq contex.

Although we found this problem on linux 4.4, the latest kernel version
seems to have this problem as well. And it is very similar to the
previous one:
	https://lkml.org/lkml/2018/7/9/391

Fix it by using RCU workqueue, which allows sleep.

Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-28 09:08:27 -07:00
Jens Axboe 4711b57317 blk-mq: fix failure to decrement plug count on single rq removal
If we yank a 'same_queue_rq' request off the plug list, we should
also decrement the cached request count.

Fixes: 5f0ed774ed ("block: sum requests in the plug structure")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-28 06:29:23 -07:00
Young Xiao a11f6ca9ae sunvdc: Do not spin in an infinite loop when vio_ldc_send() returns EAGAIN
__vdc_tx_trigger should only loop on EAGAIN a finite
number of times.

See commit adddc32d6f ("sunvnet: Do not spin in an
infinite loop when vio_ldc_send() returns EAGAIN") for detail.

Signed-off-by: Young Xiao <YangX92@hotmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-28 06:23:12 -07:00
Jens Axboe 5f0ed774ed block: sum requests in the plug structure
This isn't exactly the same as the previous count, as it includes
requests for all devices. But that really doesn't matter, if we have
more than the threshold (16) queued up, flush it. It's not worth it
to have an expensive list loop for this.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-26 10:35:22 -07:00
Keith Busch af78ff7c6e blk-mq: Simplify request completion state
There are no more users relying on blk-mq request states to prevent
double completions, so replace the relatively expensive cmpxchg operation
with WRITE_ONCE.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-26 10:34:27 -07:00
Keith Busch f1342709d1 scsi: Do not rely on blk-mq for double completions
The scsi timeout error handling had been directly updating the block
layer's request state to prevent a error handling and a natural completion
from completing the same request twice. Fix this layering violation
by having scsi control the fate of its commands with scsi owned flags
rather than use blk-mq's.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-26 10:34:26 -07:00
Keith Busch 16c15eb16a blk-mq: Return true if request was completed
A driver may have internal state to cleanup if we're pretending a request
didn't complete. Return 'false' if the command wasn't actually completed
due to the timeout error injection, and true otherwise.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-26 10:34:24 -07:00
Jens Axboe 4ab32bf330 blk-mq: never redirect polled IO completions
It's pointless to do so, we are by definition on the CPU we want/need
to be, as that's the one waiting for a completion event.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-26 08:26:04 -07:00
Jens Axboe aa61bec30e blk-mq: ensure mq_ops ->poll() is entered at least once
Right now we immediately bail if need_resched() is true, but
we need to do at least one loop in case we have entries waiting.
So just invert the need_resched() check, putting it at the
bottom of the loop.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-26 08:25:57 -07:00
Jens Axboe 0a1b8b87d0 block: make blk_poll() take a parameter on whether to spin or not
blk_poll() has always kept spinning until it found an IO. This is
fine for SYNC polling, since we need to find one request we have
pending, but in preparation for ASYNC polling it can be beneficial
to just check if we have any entries available or not.

Existing callers are converted to pass in 'spin == true', to retain
the old behavior.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-26 08:25:53 -07:00
Jens Axboe e7d9439107 nvme: remove opportunistic polling from bdev target
It doesn't set HIPRI on the bio, so polling for it is pretty silly.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-26 08:25:48 -07:00
Jens Axboe 9743139c5d blk-mq: remove 'tag' parameter from mq_ops->poll()
We always pass in -1 now and none of the callers use the tag value,
remove the parameter.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-26 08:25:44 -07:00
Jens Axboe 1052b8ac52 blk-mq: when polling for IO, look for any completion
If we want to support async IO polling, then we have to allow finding
completions that aren't just for the one we are looking for. Always pass
in -1 to the mq_ops->poll() helper, and have that return how many events
were found in this poll loop.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-26 08:25:40 -07:00
Ming Lei 1db4909e76 blk-mq: not embed .mq_kobj and ctx->kobj into queue instance
Even though .mq_kobj, ctx->kobj and q->kobj share same lifetime
from block layer's view, actually they don't because userspace may
grab one kobject anytime via sysfs.

This patch fixes the issue by the following approach:

1) introduce 'struct blk_mq_ctxs' for holding .mq_kobj and managing
all ctxs

2) free all allocated ctxs and the 'blk_mq_ctxs' instance in release
handler of .mq_kobj

3) grab one ref of .mq_kobj before initializing each ctx->kobj, so that
.mq_kobj is always released after all ctxs are freed.

This patch fixes kernel panic issue during booting when DEBUG_KOBJECT_RELEASE
is enabled.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: "jianchao.wang" <jianchao.w.wang@oracle.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-21 05:57:56 -07:00
Jens Axboe 0c62bff1fd block: fix attempt to assign NULL io_context
If the first request allocated and issued by a process is a passhthrough
request, we don't set up an IO context for it. Ensure that
blk_mq_sched_assign_ioc() ignores a NULL io_context.

Fixes: e2b3fa5af7 ("block: Remove bio->bi_ioc")
Reported-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-20 19:12:46 -07:00
Damien Le Moal 20578bdfd0 block: Initialize BIO I/O priority early
For the synchronous I/O path case (read(), write() etc system calls), a
BIO I/O priority is not initialized until the execution of
blk_init_request_from_bio() when the BIO is submitted and a request
initialized for the BIO execution. This is due to the ki_ioprio field of
the struct kiocb defined on stack being always initialized to
IOPRIO_CLASS_NONE, regardless of the calling process I/O context ioprio
value set with ioprio_set(). This late initialization can result in the
BIO being merged to pending requests even when the I/O priorities
differ.

Fix this by initializing the ki_iopriority field of on stack struct
kiocb using the get_current_ioprio() helper, ensuring that all BIOs
allocated and submitted for the system call execution see the correct
intended I/O priority early. With this, since a BIO I/O priority is
always set to the intended effective value for both the sync and async
path, blk_init_request_from_bio() can be simplified.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Adam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 19:03:50 -07:00
Damien Le Moal 668ffc0341 block: prevent merging of requests with different priorities
Growing in size a high priority request by merging it with a lower
priority BIO or request will increase the request execution time. This
is the opposite result of the desired effect of high I/O priorities,
namely getting low I/O latencies. Prevent merging of requests and BIOs
that have different I/O priorities to fix this.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 19:03:49 -07:00
Damien Le Moal 76dc891395 aio: Fix fallback I/O priority value
For cases when the application does not specify aio_reqprio for an aio,
fallback to use get_current_ioprio() to obtain the task I/O priority
last set using ioprio_set() rather than the hardcoded IOPRIO_CLASS_NONE
value.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Adam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 19:03:47 -07:00
Damien Le Moal 64845a1ddd block: Introduce get_current_ioprio()
Define get_current_ioprio() as an inline helper to obtain the caller
I/O priority from its task I/O context. Use this helper in
blk_init_request_from_bio() to set a request ioprio.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 19:03:46 -07:00
Damien Le Moal e2b3fa5af7 block: Remove bio->bi_ioc
bio->bi_ioc is never set so always NULL. Remove references to it in
bio_disassociate_task() and in rq_ioc() and delete this field from
struct bio. With this change, rq_ioc() always returns
current->io_context without the need for a bio argument. Further
simplify the code and make it more readable by also removing this
helper, which also allows to simplify blk_mq_sched_assign_ioc() by
removing its bio argument.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Adam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 19:03:44 -07:00
Damien Le Moal 23464f8c34 aio: Comment use of IOCB_FLAG_IOPRIO aio flag
Comment the use of the IOCB_FLAG_IOPRIO aio flag similarly to the
IOCB_FLAG_RESFD flag.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 19:03:43 -07:00
Jens Axboe 92f806d678 nvme-fc: remove ->poll implementation
It's specifically looking for a given request, which we will not be
supporting going forward. Also kill the qla2xxx poll implementation
as that's the only user of the nvme-fc poll, and the now unused
->poll_queue() hook.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by:  James Smart <jsmart2021@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 12:06:32 -07:00
Jens Axboe 85f4d4b65f block: have ->poll_fn() return number of entries polled
We currently only really support sync poll, ie poll with 1 IO in flight.
This prepares us for supporting async poll.

Note that the returned value isn't necessarily 100% accurate. If poll
races with IRQ completion, we assume that the fact that the task is now
runnable means we found at least one entry. In reality it could be more
than 1, or not even 1. This is fine, the caller will just need to take
this into account.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 08:34:50 -07:00
Jens Axboe 849a370016 block: avoid ordered task state change for polled IO
For the core poll helper, the task state setting don't need to imply any
atomics, as it's the current task itself that is being modified and
we're not going to sleep.

For IRQ driven, the wakeup path have the necessary barriers to not need
us using the heavy handed version of the task state setting.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 08:34:49 -07:00
Jens Axboe a4668d9ba4 nvme: default to 0 poll queues
We need a better way of configuring this, and given that polling is
(still) a bit niche, let's default to using 0 poll queues. That way
we'll have the same read/write/poll behavior as 4.20, and users that
want to test/use polling are required to do manual configuration of the
number of poll queues.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-19 08:18:24 -07:00
Jens Axboe a78b03bc73 Linux 4.20-rc3
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Merge tag 'v4.20-rc3' into for-4.21/block

Merge in -rc3 to resolve a few conflicts, but also to get a few
important fixes that have gone into mainline since the block
4.21 branch was forked off (most notably the SCSI queue issue,
which is both a conflict AND needed fix).

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-18 15:46:03 -07:00
Jens Axboe fce15a609f floppy: remove now unused 'flags' variable
With the locking removed, it's unused. Kill it.

Fixes: 503f620f0c ("floppy: remove queue_lock around floppy_end_request")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-18 15:42:48 -07:00
Linus Torvalds 9ff01193a2 Linux 4.20-rc3 2018-11-18 13:33:44 -08:00
Linus Torvalds 25e19c1fe4 libnvdimm 4.20-rc3
- Address Range Scrub overflow continuation handling has been broken
   since it was initially merged. It was only recently that error injection
   and platform-BIOS support enabled this corner case to be exercised.
 
 - The recent attempt to provide more isolation for the kernel Address
   Range Scrub state machine from userapace initiated sessions triggers a
   lockdep report. Revert and try again at the next merge window.
 
 - Fix a kasan reported buffer overflow in libnvdimm unit test
   infrastrucutre (nfit_test)
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Merge tag 'libnvdimm-fixes-4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:
 "A small batch of fixes for v4.20-rc3.

  The overflow continuation fix addresses something that has been broken
  for several releases. Arguably it could wait even longer, but it's a
  one line fix and this finishes the last of the known address range
  scrub bug reports. The revert addresses a lockdep regression. The unit
  tests are not critical to fix, but no reason to hold this fix back.

  Summary:

   - Address Range Scrub overflow continuation handling has been broken
     since it was initially merged. It was only recently that error
     injection and platform-BIOS support enabled this corner case to be
     exercised.

   - The recent attempt to provide more isolation for the kernel Address
     Range Scrub state machine from userapace initiated sessions
     triggers a lockdep report. Revert and try again at the next merge
     window.

   - Fix a kasan reported buffer overflow in libnvdimm unit test
     infrastrucutre (nfit_test)"

* tag 'libnvdimm-fixes-4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  Revert "acpi, nfit: Further restrict userspace ARS start requests"
  acpi, nfit: Fix ARS overflow continuation
  tools/testing/nvdimm: Fix the array size for dimm devices.
2018-11-18 12:21:09 -08:00
Linus Torvalds c67a98c00e Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "16 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm/memblock.c: fix a typo in __next_mem_pfn_range() comments
  mm, page_alloc: check for max order in hot path
  scripts/spdxcheck.py: make python3 compliant
  tmpfs: make lseek(SEEK_DATA/SEK_HOLE) return ENXIO with a negative offset
  lib/ubsan.c: don't mark __ubsan_handle_builtin_unreachable as noreturn
  mm/vmstat.c: fix NUMA statistics updates
  mm/gup.c: fix follow_page_mask() kerneldoc comment
  ocfs2: free up write context when direct IO failed
  scripts/faddr2line: fix location of start_kernel in comment
  mm: don't reclaim inodes with many attached pages
  mm, memory_hotplug: check zone_movable in has_unmovable_pages
  mm/swapfile.c: use kvzalloc for swap_info_struct allocation
  MAINTAINERS: update OMAP MMC entry
  hugetlbfs: fix kernel BUG at fs/hugetlbfs/inode.c:444!
  kernel/sched/psi.c: simplify cgroup_move_task()
  z3fold: fix possible reclaim races
2018-11-18 11:31:26 -08:00
Linus Torvalds 03582f338e Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Ingo Molnar:
 "Fix an exec() related scalability/performance regression, which was
  caused by incorrectly calculating load and migrating tasks on exec()
  when they shouldn't be"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix cpu_util_wake() for 'execl' type workloads
2018-11-18 10:58:20 -08:00
Linus Torvalds b53e27f618 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Fix uncore PMU enumeration for CofeeLake CPUs"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/uncore: Support CoffeeLake 8th CBOX
  perf/x86/intel/uncore: Add more IMC PCI IDs for KabyLake and CoffeeLake CPUs
2018-11-18 10:54:59 -08:00
Linus Torvalds 743a4863fd Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fixes from Ingo Molnar:
 "Misc fixes: two warning splat fixes, a leak fix and persistent memory
  allocation fixes for ARM"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Permit calling efi_mem_reserve_persistent() from atomic context
  efi/arm: Defer persistent reservations until after paging_init()
  efi/arm/libstub: Pack FDT after populating it
  efi/arm: Revert deferred unmap of early memmap mapping
  efi: Fix debugobjects warning on 'efi_rts_work'
2018-11-18 10:52:26 -08:00
Linus Torvalds cfaa9f029f Merge branch 'spectre' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM spectre updates from Russell King:
 "These are the currently known final bits that resolve the Spectre
  issues. big.Little systems used to be sufficiently identical in that
  there were no differences between individual CPUs in the system that
  mattered to the kernel. With the advent of the Spectre problem, the
  CPUs now have differences in how the workaround is applied.

  As a result of previous Spectre patches, these systems ended up
  reporting quite a lot of:

     "CPUx: Spectre v2: incorrect context switching function, system vulnerable"

  messages due to the action of the big.Little switcher causing the CPUs
  to be re-initialised regularly. This series resolves that issue by
  making the CPU vtable unique to each CPU.

  However, since this is used very early, before per-cpu is setup,
  per-cpu can't be used. We also have a problem that two of the methods
  are not called from preempt-safe paths, but thankfully these remain
  identical between all CPUs in the system. To make sure, we validate
  that these are identical during boot"

* 'spectre' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: spectre-v2: per-CPU vtables to work around big.Little systems
  ARM: add PROC_VTABLE and PROC_TABLE macros
  ARM: clean up per-processor check_bugs method call
  ARM: split out processor lookup
  ARM: make lookup_processor_type() non-__init
2018-11-18 10:45:09 -08:00
Chen Chang 45e79815b8 mm/memblock.c: fix a typo in __next_mem_pfn_range() comments
Link: http://lkml.kernel.org/r/20181107100247.13359-1-rainccrun@gmail.com
Signed-off-by: Chen Chang <rainccrun@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-18 10:15:10 -08:00
Michal Hocko c63ae43ba5 mm, page_alloc: check for max order in hot path
Konstantin has noticed that kvmalloc might trigger the following
warning:

  WARNING: CPU: 0 PID: 6676 at mm/vmstat.c:986 __fragmentation_index+0x54/0x60
  [...]
  Call Trace:
   fragmentation_index+0x76/0x90
   compaction_suitable+0x4f/0xf0
   shrink_node+0x295/0x310
   node_reclaim+0x205/0x250
   get_page_from_freelist+0x649/0xad0
   __alloc_pages_nodemask+0x12a/0x2a0
   kmalloc_large_node+0x47/0x90
   __kmalloc_node+0x22b/0x2e0
   kvmalloc_node+0x3e/0x70
   xt_alloc_table_info+0x3a/0x80 [x_tables]
   do_ip6t_set_ctl+0xcd/0x1c0 [ip6_tables]
   nf_setsockopt+0x44/0x60
   SyS_setsockopt+0x6f/0xc0
   do_syscall_64+0x67/0x120
   entry_SYSCALL_64_after_hwframe+0x3d/0xa2

the problem is that we only check for an out of bound order in the slow
path and the node reclaim might happen from the fast path already.  This
is fixable by making sure that kvmalloc doesn't ever use kmalloc for
requests that are larger than KMALLOC_MAX_SIZE but this also shows that
the code is rather fragile.  A recent UBSAN report just underlines that
by the following report

  UBSAN: Undefined behaviour in mm/page_alloc.c:3117:19
  shift exponent 51 is too large for 32-bit type 'int'
  CPU: 0 PID: 6520 Comm: syz-executor1 Not tainted 4.19.0-rc2 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0xd2/0x148 lib/dump_stack.c:113
   ubsan_epilogue+0x12/0x94 lib/ubsan.c:159
   __ubsan_handle_shift_out_of_bounds+0x2b6/0x30b lib/ubsan.c:425
   __zone_watermark_ok+0x2c7/0x400 mm/page_alloc.c:3117
   zone_watermark_fast mm/page_alloc.c:3216 [inline]
   get_page_from_freelist+0xc49/0x44c0 mm/page_alloc.c:3300
   __alloc_pages_nodemask+0x21e/0x640 mm/page_alloc.c:4370
   alloc_pages_current+0xcc/0x210 mm/mempolicy.c:2093
   alloc_pages include/linux/gfp.h:509 [inline]
   __get_free_pages+0x12/0x60 mm/page_alloc.c:4414
   dma_mem_alloc+0x36/0x50 arch/x86/include/asm/floppy.h:156
   raw_cmd_copyin drivers/block/floppy.c:3159 [inline]
   raw_cmd_ioctl drivers/block/floppy.c:3206 [inline]
   fd_locked_ioctl+0xa00/0x2c10 drivers/block/floppy.c:3544
   fd_ioctl+0x40/0x60 drivers/block/floppy.c:3571
   __blkdev_driver_ioctl block/ioctl.c:303 [inline]
   blkdev_ioctl+0xb3c/0x1a30 block/ioctl.c:601
   block_ioctl+0x105/0x150 fs/block_dev.c:1883
   vfs_ioctl fs/ioctl.c:46 [inline]
   do_vfs_ioctl+0x1c0/0x1150 fs/ioctl.c:687
   ksys_ioctl+0x9e/0xb0 fs/ioctl.c:702
   __do_sys_ioctl fs/ioctl.c:709 [inline]
   __se_sys_ioctl fs/ioctl.c:707 [inline]
   __x64_sys_ioctl+0x7e/0xc0 fs/ioctl.c:707
   do_syscall_64+0xc4/0x510 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Note that this is not a kvmalloc path.  It is just that the fast path
really depends on having sanitzed order as well.  Therefore move the
order check to the fast path.

Link: http://lkml.kernel.org/r/20181113094305.GM15120@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reported-by: Kyungtae Kim <kt0755@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Byoungyoung Lee <lifeasageek@gmail.com>
Cc: "Dae R. Jeong" <threeearcat@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-18 10:15:10 -08:00
Uwe Kleine-König 6f4d29df66 scripts/spdxcheck.py: make python3 compliant
Without this change the following happens when using Python3 (3.6.6):

	$ echo "GPL-2.0" | python3 scripts/spdxcheck.py -
	FAIL: 'str' object has no attribute 'decode'
	Traceback (most recent call last):
	  File "scripts/spdxcheck.py", line 253, in <module>
	    parser.parse_lines(sys.stdin, args.maxlines, '-')
	  File "scripts/spdxcheck.py", line 171, in parse_lines
	    line = line.decode(locale.getpreferredencoding(False), errors='ignore')
	AttributeError: 'str' object has no attribute 'decode'

So as the line is already a string, there is no need to decode it and
the line can be dropped.

/usr/bin/python on Arch is Python 3.  So this would indeed be worth
going into 4.19.

Link: http://lkml.kernel.org/r/20181023070802.22558-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-18 10:15:10 -08:00