linux.git/block, branch v4.1.17

blk-mq: fix buffer overflow when reading sysfs file of 'pending'

2015-09-29T17:25:56+00:00

commit 596f5aad2a704b72934e5abec1b1b4114c16f45b upstream.

There may be lots of pending requests so that the buffer of PAGE_SIZE
can't hold them at all.

One typical example is scsi-mq, the queue depth(.can_queue) of
scsi_host and blk-mq is quite big but scsi_device's queue_depth
is a bit small(.cmd_per_lun), then it is quite easy to have lots
of pending requests in hw queue.

This patch fixes the following warning and the related memory
destruction.

[  359.025101] fill_read_buffer: blk_mq_hw_sysfs_show+0x0/0x7d returned bad count^M
[  359.055595] irq event stamp: 15537^M
[  359.055606] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC ^M
[  359.055614] Dumping ftrace buffer:^M
[  359.055660]    (ftrace buffer empty)^M
[  359.055672] Modules linked in: nbd ipv6 kvm_intel kvm serio_raw^M
[  359.055678] CPU: 4 PID: 21631 Comm: stress-ng-sysfs Not tainted 4.2.0-rc5-next-20150805 #434^M
[  359.055679] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011^M
[  359.055682] task: ffff8802161cc000 ti: ffff88021b4a8000 task.ti: ffff88021b4a8000^M
[  359.055693] RIP: 0010:[]  [] __kmalloc+0xe8/0x152^M

Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

sd: Fix maximum I/O size for BLOCK_PC requests

2015-09-13T16:07:45+00:00

commit 4f258a46346c03fa0bbb6199ffaf4e1f9f599660 upstream.

Commit bcdb247c6b6a ("sd: Limit transfer length") clamped the maximum
size of an I/O request to the MAXIMUM TRANSFER LENGTH field in the BLOCK
LIMITS VPD. This had the unfortunate effect of also limiting the maximum
size of non-filesystem requests sent to the device through sg/bsg.

Avoid using blk_queue_max_hw_sectors() and set the max_sectors queue
limit directly.

Also update the comment in blk_limits_max_hw_sectors() to clarify that
max_hw_sectors defines the limit for the I/O controller only.

Signed-off-by: Martin K. Petersen 
Reported-by: Brian King 
Tested-by: Brian King 
Signed-off-by: James Bottomley 
Signed-off-by: Greg Kroah-Hartman

blk-mq: set default timeout as 30 seconds

2015-08-10T19:21:57+00:00

commit e56f698bd0720e17f10f39e8b0b5b446ad0ab22c upstream.

It is reasonable to set default timeout of request as 30 seconds instead of
30000 ticks, which may be 300 seconds if HZ is 100, for example, some arm64
based systems may choose 100 HZ.

Signed-off-by: Ming Lei 
Fixes: c76cbbcf4044 ("blk-mq: put blk_queue_rq_timeout together in blk_mq_init_queue()"
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

blkcg: fix gendisk reference leak in blkg_conf_prep()

2015-08-10T19:21:56+00:00

commit 5f6c2d2b7dbb541c1e922538c49fa04c494ae3d7 upstream.

When a blkcg configuration is targeted to a partition rather than a
whole device, blkg_conf_prep fails with -EINVAL; unfortunately, it
forgets to put the gendisk ref in that case.  Fix it.

Signed-off-by: Tejun Heo 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

bio integrity: do not assume bio_integrity_pool exists if bioset exists

2015-08-10T19:21:52+00:00

commit bb8bd38b9a1685334b73e8c62e128cbedb875867 upstream.

bio_integrity_alloc() and bio_integrity_free() assume that if a bio was
allocated from a bioset that that bioset also had its bio_integrity_pool
allocated using bioset_integrity_create().  This is a very bad
assumption given that bioset_create() and bioset_integrity_create() are
completely disjoint.  Not all callers of bioset_create() have been
trained to also call bioset_integrity_create() -- and they may not care
to be.

Fix this by falling back to kmalloc'ing 'struct bio_integrity_payload'
rather than force all bioset consumers to (wastefully) preallocate a
bio_integrity_pool that they very likely won't actually need (given the
niche nature of the current block integrity support).

Otherwise, a NULL pointer "Kernel BUG" with a trace like the following
will be observed (as seen on s390x using zfcp storage) because dm-io
doesn't use bioset_integrity_create() when creating its bioset:

    [  791.643338] Call Trace:
    [  791.643339] ([<00000003df98b848>] 0x3df98b848)
    [  791.643341]  [<00000000002c5de8>] bio_integrity_alloc+0x48/0xf8
    [  791.643348]  [<00000000002c6486>] bio_integrity_prep+0xae/0x2f0
    [  791.643349]  [<0000000000371e38>] blk_queue_bio+0x1c8/0x3d8
    [  791.643355]  [<000000000036f8d0>] generic_make_request+0xc0/0x100
    [  791.643357]  [<000000000036f9b2>] submit_bio+0xa2/0x198
    [  791.643406]  [<000003ff801f9774>] dispatch_io+0x15c/0x3b0 [dm_mod]
    [  791.643419]  [<000003ff801f9b3e>] dm_io+0x176/0x2f0 [dm_mod]
    [  791.643423]  [<000003ff8074b28a>] do_reads+0x13a/0x1a8 [dm_mirror]
    [  791.643425]  [<000003ff8074b43a>] do_mirror+0x142/0x298 [dm_mirror]
    [  791.643428]  [<0000000000154fca>] process_one_work+0x18a/0x3f8
    [  791.643432]  [<000000000015598a>] worker_thread+0x132/0x3b0
    [  791.643435]  [<000000000015d49a>] kthread+0xd2/0xd8
    [  791.643438]  [<00000000005bc0ca>] kernel_thread_starter+0x6/0xc
    [  791.643446]  [<00000000005bc0c4>] kernel_thread_starter+0x0/0xc

Signed-off-by: Mike Snitzer 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: Do a full clone when splitting discard bios

2015-08-03T16:29:07+00:00

commit f3f5da624e0a891c34d8cd513c57f1d9b0c7dadc upstream.

This fixes a data corruption bug when using discard on top of MD linear,
raid0 and raid10 personalities.

Commit 20d0189b1012 "block: Introduce new bio_split()" permits sharing
the bio_vec between the two resulting bios. That is fine for read/write
requests where the bio_vec is immutable. For discards, however, we need
to be able to attach a payload and update the bio_vec so the page can
get mapped to a scatterlist entry. Therefore the bio_vec can not be
shared when splitting discards and we must do a full clone.

Signed-off-by: Martin K. Petersen 
Reported-by: Seunguk Shin 
Tested-by: Seunguk Shin 
Cc: Seunguk Shin 
Cc: Jens Axboe 
Cc: Kent Overstreet 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block: fix ext_dev_lock lockdep report

2015-06-11T15:01:40+00:00

 =================================
 [ INFO: inconsistent lock state ]
 4.1.0-rc7+ #217 Tainted: G           O
 ---------------------------------
 inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
 swapper/6/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
  (ext_devt_lock){+.?...}, at: [] blk_free_devt+0x3c/0x70
 {SOFTIRQ-ON-W} state was registered at:
   [] __lock_acquire+0x461/0x1e70
   [] lock_acquire+0xb7/0x290
   [] _raw_spin_lock+0x38/0x50
   [] blk_alloc_devt+0x6d/0xd0  <-- take the lock in process context
[..]
  [] __lock_acquire+0x3fe/0x1e70
  [] ? __lock_acquire+0xe5d/0x1e70
  [] lock_acquire+0xb7/0x290
  [] ? blk_free_devt+0x3c/0x70
  [] _raw_spin_lock+0x38/0x50
  [] ? blk_free_devt+0x3c/0x70
  [] blk_free_devt+0x3c/0x70    <-- take the lock in softirq
  [] part_release+0x1c/0x50
  [] device_release+0x36/0xb0
  [] kobject_cleanup+0x7b/0x1a0
  [] kobject_put+0x30/0x70
  [] put_device+0x17/0x20
  [] delete_partition_rcu_cb+0x16c/0x180
  [] ? read_dev_sector+0xa0/0xa0
  [] rcu_process_callbacks+0x2ff/0xa90
  [] ? rcu_process_callbacks+0x2bf/0xa90
  [] __do_softirq+0xde/0x600

Neil sees this in his tests and it also triggers on pmem driver unbind
for the libnvdimm tests.  This fix is on top of an initial fix by Keith
for incorrect usage of mutex_lock() in this path: 2da78092dda1 "block:
Fix dev_t minor allocation lifetime".  Both this and 2da78092dda1 are
candidates for -stable.

Fixes: 2da78092dda1 ("block: Fix dev_t minor allocation lifetime")
Cc: 
Cc: Keith Busch 
Reported-by: NeilBrown 
Signed-off-by: Dan Williams 
Signed-off-by: Jens Axboe

blk-mq: free hctx->ctxs in queue's release handler

2015-06-09T21:32:38+00:00

Now blk_cleanup_queue() can be called before calling
del_gendisk()[1], inside which hctx->ctxs is touched
from blk_mq_unregister_hctx(), but the variable has
been freed by blk_cleanup_queue() at that time.

So this patch moves freeing of hctx->ctxs into queue's
release handler for fixing the oops reported by Stefan.

[1], 6cd18e711dd8075 (block: destroy bdi before blockdev is
unregistered)

Reported-by: Stefan Seyfried 
Cc: NeilBrown 
Cc: Christoph Hellwig 
Cc: stable@vger.kernel.org (v4.0)
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe

block: discard bdi_unregister() in favour of bdi_destroy()

2015-05-28T16:12:42+00:00

bdi_unregister() now contains very little functionality.

It contains a "WARN_ON" if bdi->dev is NULL.  This warning is of no
real consequence as bdi->dev isn't needed by anything else in the function,
and it triggers if
   blk_cleanup_queue() -> bdi_destroy()
is called before bdi_unregister, which happens since
  Commit: 6cd18e711dd8 ("block: destroy bdi before blockdev is unregistered.")

So this isn't wanted.

It also calls bdi_set_min_ratio().  This needs to be called after
writes through the bdi have all been flushed, and before the bdi is destroyed.
Calling it early is better than calling it late as it frees up a global
resource.

Calling it immediately after bdi_wb_shutdown() in bdi_destroy()
perfectly fits these requirements.

So bdi_unregister() can be discarded with the important content moved to
bdi_destroy(), as can the
  writeback_bdi_unregister
event which is already not used.

Reported-by: Mike Snitzer 
Cc: stable@vger.kernel.org (v4.0)
Fixes: c4db59d31e39 ("fs: don't reassign dirty inodes to default_backing_dev_info")
Fixes: 6cd18e711dd8 ("block: destroy bdi before blockdev is unregistered.")
Acked-by: Peter Zijlstra (Intel) 
Acked-by: Dan Williams 
Tested-by: Nicholas Moulin 
Signed-off-by: NeilBrown 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: remove export for blk_queue_bio

2015-05-12T21:21:22+00:00

With commit ff36ab345 ("dm: remove request-based logic from
make_request_fn wrapper") DM no longer calls blk_queue_bio() directly,
so remove its export.  Doing so required a forward declaration in
blk-core.c.

Signed-off-by: Mike Snitzer 
Signed-off-by: Jens Axboe