Commit Graph

7470 Commits

Author SHA1 Message Date
Mikulas Patocka
137227f963 Revert "dm: requeue IO if mapping table not yet available"
[ Upstream commit c8691cd0fc11197515ed148de0780d927bfca38b ]

This reverts commit fa247089de.

The following sequence of commands causes a livelock - there will be
workqueue process looping and consuming 100% CPU:

dmsetup create --notable test
truncate -s 1MiB testdata
losetup /dev/loop0 testdata
dmsetup load test --table '0 2048 linear /dev/loop0 0'
dd if=/dev/zero of=/dev/dm-0 bs=16k count=1 conv=fdatasync

The livelock is caused by the commit fa247089de. The commit claims that
it fixes a race condition, however, it is unknown what the actual race
condition is and what program is involved in the race condition.

When the inactive table is loaded, the nodes /dev/dm-0 and
/sys/block/dm-0 are created. /dev/dm-0 has zero size at this point. When
the device is suspended and resumed, the nodes /dev/mapper/test and
/dev/disk/* are created.

If some program opens a block device before it is created by dmsetup or
lvm, the program is buggy, so dm could just report an error as it used to
do before.

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: fa247089de ("dm: requeue IO if mapping table not yet available")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-17 15:21:12 +02:00
Mikulas Patocka
d3fccbfaca dm-integrity: fix a race condition when accessing recalc_sector
commit f8e1ca92e35e9041cc0a1bc226ef07a853a22de4 upstream.

There's a race condition when accessing the variable
ic->sb->recalc_sector. The function integrity_recalc writes to this
variable when it makes some progress and the function
dm_integrity_map_continue may read this variable concurrently.

One problem is that on 32-bit architectures the 64-bit variable is not
read and written atomically - it may be possible to read garbage if read
races with write.

Another problem is that memory accesses to this variable are not guarded
with memory barriers.

This commit fixes the race - it moves reading ic->sb->recalc_sector to an
earlier place where we hold &ic->endio_wait.lock.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-18 19:23:04 +02:00
Benjamin Marzinski
23e48f5d26 dm init: Handle minors larger than 255
[ Upstream commit 140ce37fd78a629105377e17842465258a5459ef ]

dm_parse_device_entry() simply copies the minor number into dmi.dev, but
the dev_t format splits the minor number between the lowest 8 bytes and
highest 12 bytes. If the minor number is larger than 255, part of it
will end up getting treated as the major number

Fix this by checking that the minor number is valid and then encoding it
as a dev_t.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-12 11:10:22 +02:00
Mikulas Patocka
cdbf424d9b dm suspend: return -ERESTARTSYS instead of -EINTR
[ Upstream commit 1e1fd567d32fcf7544c6e09e0e5bc6c650da6e23 ]

This commit changes device mapper, so that it returns -ERESTARTSYS
instead of -EINTR when it is interrupted by a signal (so that the ioctl
can be restarted).

The manpage signal(7) says that the ioctl function should be restarted if
the signal was handled with SA_RESTART.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29 17:30:41 +02:00
Li Nan
86ea3c4e71 md: clean up invalid BUG_ON in md_ioctl
[ Upstream commit 9dd8702e7cd28ebf076ff838933f29cf671165ec ]

'disk->private_data' is set to mddev in md_alloc() and never set to NULL,
and users need to open mddev before submitting ioctl. So mddev must not
have been freed during ioctl, and there is no need to check mddev here.
Clean up it.

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240226031444.3606764-4-linan666@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29 17:30:36 +02:00
Yu Kuai
9a3ff24192 md/raid5-cache: use READ_ONCE/WRITE_ONCE for 'conf->log'
[ Upstream commit 06a4d0d8c642b5ea654e832b74dca12965356da0 ]

'conf->log' is set with 'reconfig_mutex' grabbed, however, readers are
not procted, hence protect it with READ_ONCE/WRITE_ONCE to prevent
reading abnormal values.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-3-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29 17:30:30 +02:00
Alexander Lobakin
8cd74c5d5e bitmap: introduce generic optimized bitmap_size()
commit a37fbe666c016fd89e4460d0ebfcea05baba46dc upstream.

The number of times yet another open coded
`BITS_TO_LONGS(nbits) * sizeof(long)` can be spotted is huge.
Some generic helper is long overdue.

Add one, bitmap_size(), but with one detail.
BITS_TO_LONGS() uses DIV_ROUND_UP(). The latter works well when both
divident and divisor are compile-time constants or when the divisor
is not a pow-of-2. When it is however, the compilers sometimes tend
to generate suboptimal code (GCC 13):

48 83 c0 3f          	add    $0x3f,%rax
48 c1 e8 06          	shr    $0x6,%rax
48 8d 14 c5 00 00 00 00	lea    0x0(,%rax,8),%rdx

%BITS_PER_LONG is always a pow-2 (either 32 or 64), but GCC still does
full division of `nbits + 63` by it and then multiplication by 8.
Instead of BITS_TO_LONGS(), use ALIGN() and then divide by 8. GCC:

8d 50 3f             	lea    0x3f(%rax),%edx
c1 ea 03             	shr    $0x3,%edx
81 e2 f8 ff ff 1f    	and    $0x1ffffff8,%edx

Now it shifts `nbits + 63` by 3 positions (IOW performs fast division
by 8) and then masks bits[2:0]. bloat-o-meter:

add/remove: 0/0 grow/shrink: 20/133 up/down: 156/-773 (-617)

Clang does it better and generates the same code before/after starting
from -O1, except that with the ALIGN() approach it uses %edx and thus
still saves some bytes:

add/remove: 0/0 grow/shrink: 9/133 up/down: 18/-538 (-520)

Note that we can't expand DIV_ROUND_UP() by adding a check and using
this approach there, as it's used in array declarations where
expressions are not allowed.
Add this helper to tools/ as well.

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-29 17:30:14 +02:00
Mikulas Patocka
4296218771 dm persistent data: fix memory allocation failure
commit faada2174c08662ae98b439c69efe3e79382c538 upstream.

kmalloc is unreliable when allocating more than 8 pages of memory. It may
fail when there is plenty of free memory but the memory is fragmented.
Zdenek Kabelac observed such failure in his tests.

This commit changes kmalloc to kvmalloc - kvmalloc will fall back to
vmalloc if the large allocation fails.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-29 17:30:14 +02:00
Khazhismel Kumykov
134e8a34b4 dm resume: don't return EINVAL when signalled
commit 7a636b4f03af9d541205f69e373672e7b2b60a8a upstream.

If the dm_resume method is called on a device that is not suspended, the
method will suspend the device briefly, before resuming it (so that the
table will be swapped).

However, there was a bug that the return value of dm_suspended_md was not
checked. dm_suspended_md may return an error when it is interrupted by a
signal. In this case, do_resume would call dm_swap_table, which would
return -EINVAL.

This commit fixes the logic, so that error returned by dm_suspend is
checked and the resume operation is undone.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-29 17:30:14 +02:00
Yu Kuai
3b33740c17 md/raid5: avoid BUG_ON() while continue reshape after reassembling
[ Upstream commit 305a5170dc5cf3d395bb4c4e9239bca6d0b54b49 ]

Currently, mdadm support --revert-reshape to abort the reshape while
reassembling, as the test 07revert-grow. However, following BUG_ON()
can be triggerred by the test:

kernel BUG at drivers/md/raid5.c:6278!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
irq event stamp: 158985
CPU: 6 PID: 891 Comm: md0_reshape Not tainted 6.9.0-03335-g7592a0b0049a #94
RIP: 0010:reshape_request+0x3f1/0xe60
Call Trace:
 <TASK>
 raid5_sync_request+0x43d/0x550
 md_do_sync+0xb7a/0x2110
 md_thread+0x294/0x2b0
 kthread+0x147/0x1c0
 ret_from_fork+0x59/0x70
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Root cause is that --revert-reshape update the raid_disks from 5 to 4,
while reshape position is still set, and after reassembling the array,
reshape position will be read from super block, then during reshape the
checking of 'writepos' that is caculated by old reshape position will
fail.

Fix this panic the easy way first, by converting the BUG_ON() to
WARN_ON(), and stop the reshape if checkings fail.

Noted that mdadm must fix --revert-shape as well, and probably md/raid
should enhance metadata validation as well, however this means
reassemble will fail and there must be user tools to fix the wrong
metadata.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240611132251.1967786-13-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-14 13:52:45 +02:00
Li Nan
38ea2243a7 md: do not delete safemode_timer in mddev_suspend
[ Upstream commit a8768a134518e406d41799a3594aeb74e0889cf7 ]

The deletion of safemode_timer in mddev_suspend() is redundant and
potentially harmful now. If timer is about to be woken up but gets
deleted, 'in_sync' will remain 0 until the next write, causing array
to stay in the 'active' state instead of transitioning to 'clean'.

Commit 0d9f4f135e ("MD: Add del_timer_sync to mddev_suspend (fix
nasty panic))" introduced this deletion for dm, because if timer fired
after dm is destroyed, the resource which the timer depends on might
have been freed.

However, commit 0dd84b3193 ("md: call __md_stop_writes in md_stop")
added __md_stop_writes() to md_stop(), which is called before freeing
resource. Timer is deleted in __md_stop_writes(), and the origin issue
is resolved. Therefore, delete safemode_timer can be removed safely now.

Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240508092053.1447930-1-linan666@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-14 13:52:45 +02:00
Eric Biggers
13f4efb2af dm-verity: fix dm_is_verity_target() when dm-verity is builtin
commit 3708c7269593b836b1d684214cd9f5d83e4ed3fd upstream.

When CONFIG_DM_VERITY=y, dm_is_verity_target() returned true for any
builtin dm target, not just dm-verity.  Fix this by checking for
verity_target instead of THIS_MODULE (which is NULL for builtin code).

Fixes: b6c1c5745c ("dm: Add verity helpers for LoadPin")
Cc: stable@vger.kernel.org
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03 08:49:43 +02:00
Li Nan
3222607081 md: fix deadlock between mddev_suspend and flush bio
[ Upstream commit 611d5cbc0b35a752e657a83eebadf40d814d006b ]

Deadlock occurs when mddev is being suspended while some flush bio is in
progress. It is a complex issue.

T1. the first flush is at the ending stage, it clears 'mddev->flush_bio'
    and tries to submit data, but is blocked because mddev is suspended
    by T4.
T2. the second flush sets 'mddev->flush_bio', and attempts to queue
    md_submit_flush_data(), which is already running (T1) and won't
    execute again if on the same CPU as T1.
T3. the third flush inc active_io and tries to flush, but is blocked because
    'mddev->flush_bio' is not NULL (set by T2).
T4. mddev_suspend() is called and waits for active_io dec to 0 which is inc
    by T3.

  T1		T2		T3		T4
  (flush 1)	(flush 2)	(third 3)	(suspend)
  md_submit_flush_data
   mddev->flush_bio = NULL;
   .
   .	 	md_flush_request
   .	  	 mddev->flush_bio = bio
   .	  	 queue submit_flushes
   .		 .
   .		 .		md_handle_request
   .		 .		 active_io + 1
   .		 .		 md_flush_request
   .		 .		  wait !mddev->flush_bio
   .		 .
   .		 .				mddev_suspend
   .		 .				 wait !active_io
   .		 .
   .		 submit_flushes
   .		 queue_work md_submit_flush_data
   .		 //md_submit_flush_data is already running (T1)
   .
   md_handle_request
    wait resume

The root issue is non-atomic inc/dec of active_io during flush process.
active_io is dec before md_submit_flush_data is queued, and inc soon
after md_submit_flush_data() run.
  md_flush_request
    active_io + 1
    submit_flushes
      active_io - 1
      md_submit_flush_data
        md_handle_request
        active_io + 1
          make_request
        active_io - 1

If active_io is dec after md_handle_request() instead of within
submit_flushes(), make_request() can be called directly intead of
md_handle_request() in md_submit_flush_data(), and active_io will
only inc and dec once in the whole flush process. Deadlock will be
fixed.

Additionally, the only difference between fixing the issue and before is
that there is no return error handling of make_request(). But after
previous patch cleaned md_write_start(), make_requst() only return error
in raid5_make_request() by dm-raid, see commit 41425f96d7aa ("dm-raid456,
md/raid456: fix a deadlock for dm-raid456 while io concurrent with
reshape)". Since dm always splits data and flush operation into two
separate io, io size of flush submitted by dm always is 0, make_request()
will not be called in md_submit_flush_data(). To prevent future
modifications from introducing issues, add WARN_ON to ensure
make_request() no error is returned in this context.

Fixes: fa2bbff7b0b4 ("md: synchronize flush io with array reconfiguration")
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240525185257.3896201-3-linan666@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03 08:48:52 +02:00
Yu Kuai
3f8d5e802d md/raid5: fix deadlock that raid5d() wait for itself to clear MD_SB_CHANGE_PENDING
commit 151f66bb618d1fd0eeb84acb61b4a9fa5d8bb0fa upstream.

Xiao reported that lvm2 test lvconvert-raid-takeover.sh can hang with
small possibility, the root cause is exactly the same as commit
bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"")

However, Dan reported another hang after that, and junxiao investigated
the problem and found out that this is caused by plugged bio can't issue
from raid5d().

Current implementation in raid5d() has a weird dependence:

1) md_check_recovery() from raid5d() must hold 'reconfig_mutex' to clear
   MD_SB_CHANGE_PENDING;
2) raid5d() handles IO in a deadloop, until all IO are issued;
3) IO from raid5d() must wait for MD_SB_CHANGE_PENDING to be cleared;

This behaviour is introduce before v2.6, and for consequence, if other
context hold 'reconfig_mutex', and md_check_recovery() can't update
super_block, then raid5d() will waste one cpu 100% by the deadloop, until
'reconfig_mutex' is released.

Refer to the implementation from raid1 and raid10, fix this problem by
skipping issue IO if MD_SB_CHANGE_PENDING is still set after
md_check_recovery(), daemon thread will be woken up when 'reconfig_mutex'
is released. Meanwhile, the hang problem will be fixed as well.

Fixes: 5e2cf333b7 ("md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d")
Cc: stable@vger.kernel.org # v5.19+
Reported-and-tested-by: Dan Moulding <dan@danm.net>
Closes: https://lore.kernel.org/all/20240123005700.9302-1-dan@danm.net/
Investigated-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240322081005.1112401-1-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-16 13:41:34 +02:00
Matthew Mirvish
934e1e4331 bcache: fix variable length array abuse in btree_iter
commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_BSETS, or from a mempool with a dynamic size based on the
specific cache set. Previously, the struct had a fixed-length array of
size MAX_BSETS which was indexed out-of-bounds for the dynamically-sized
iterators, which causes UBSAN to complain.

This patch uses the same approach as in bcachefs's sort_iter and splits
the iterator into a btree_iter with a flexible array member and a
btree_iter_stack which embeds a btree_iter as well as a fixed-length
data array.

Cc: stable@vger.kernel.org
Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039368
Signed-off-by: Matthew Mirvish <matthew@mm12.xyz>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20240509011117.2697-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-16 13:41:33 +02:00
Yu Kuai
71e8e4f288 md: fix resync softlockup when bitmap size is less than array size
[ Upstream commit f0e729af2eb6bee9eb58c4df1087f14ebaefe26b ]

Is is reported that for dm-raid10, lvextend + lvchange --syncaction will
trigger following softlockup:

kernel:watchdog: BUG: soft lockup - CPU#3 stuck for 26s! [mdX_resync:6976]
CPU: 7 PID: 3588 Comm: mdX_resync Kdump: loaded Not tainted 6.9.0-rc4-next-20240419 #1
RIP: 0010:_raw_spin_unlock_irq+0x13/0x30
Call Trace:
 <TASK>
 md_bitmap_start_sync+0x6b/0xf0
 raid10_sync_request+0x25c/0x1b40 [raid10]
 md_do_sync+0x64b/0x1020
 md_thread+0xa7/0x170
 kthread+0xcf/0x100
 ret_from_fork+0x30/0x50
 ret_from_fork_asm+0x1a/0x30

And the detailed process is as follows:

md_do_sync
 j = mddev->resync_min
 while (j < max_sectors)
  sectors = raid10_sync_request(mddev, j, &skipped)
   if (!md_bitmap_start_sync(..., &sync_blocks))
    // md_bitmap_start_sync set sync_blocks to 0
    return sync_blocks + sectors_skippe;
  // sectors = 0;
  j += sectors;
  // j never change

Root cause is that commit 301867b1c168 ("md/raid10: check
slab-out-of-bounds in md_bitmap_get_counter") return early from
md_bitmap_get_counter(), without setting returned blocks.

Fix this problem by always set returned blocks from
md_bitmap_get_counter"(), as it used to be.

Noted that this patch just fix the softlockup problem in kernel, the
case that bitmap size doesn't match array size still need to be fixed.

Fixes: 301867b1c168 ("md/raid10: check slab-out-of-bounds in md_bitmap_get_counter")
Reported-and-tested-by: Nigel Croxon <ncroxon@redhat.com>
Closes: https://lore.kernel.org/all/71ba5272-ab07-43ba-8232-d2da642acb4e@redhat.com/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240422065824.2516-1-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:03:06 +02:00
Li Nan
beaf11969f md: fix kmemleak of rdev->serial
commit 6cf350658736681b9d6b0b6e58c5c76b235bb4c4 upstream.

If kobject_add() is fail in bind_rdev_to_array(), 'rdev->serial' will be
alloc not be freed, and kmemleak occurs.

unreferenced object 0xffff88815a350000 (size 49152):
  comm "mdadm", pid 789, jiffies 4294716910
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc f773277a):
    [<0000000058b0a453>] kmemleak_alloc+0x61/0xe0
    [<00000000366adf14>] __kmalloc_large_node+0x15e/0x270
    [<000000002e82961b>] __kmalloc_node.cold+0x11/0x7f
    [<00000000f206d60a>] kvmalloc_node+0x74/0x150
    [<0000000034bf3363>] rdev_init_serial+0x67/0x170
    [<0000000010e08fe9>] mddev_create_serial_pool+0x62/0x220
    [<00000000c3837bf0>] bind_rdev_to_array+0x2af/0x630
    [<0000000073c28560>] md_add_new_disk+0x400/0x9f0
    [<00000000770e30ff>] md_ioctl+0x15bf/0x1c10
    [<000000006cfab718>] blkdev_ioctl+0x191/0x3f0
    [<0000000085086a11>] vfs_ioctl+0x22/0x60
    [<0000000018b656fe>] __x64_sys_ioctl+0xba/0xe0
    [<00000000e54e675e>] do_syscall_64+0x71/0x150
    [<000000008b0ad622>] entry_SYSCALL_64_after_hwframe+0x6c/0x74

Fixes: 963c555e75 ("md: introduce mddev_create/destroy_wb_pool for the change of member device")
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240208085556.2412922-1-linan666@huaweicloud.com
[ mddev_destroy_serial_pool third parameter was removed in mainline,
  where there is no need to suspend within this function anymore. ]
Signed-off-by: Jeremy Bongio <jbongio@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-17 11:56:24 +02:00
Arnd Bergmann
58638e3b48 dm integrity: fix out-of-range warning
[ Upstream commit 8e91c2342351e0f5ef6c0a704384a7f6fc70c3b2 ]

Depending on the value of CONFIG_HZ, clang complains about a pointless
comparison:

drivers/md/dm-integrity.c:4085:12: error: result of comparison of
                        constant 42949672950 with expression of type
                        'unsigned int' is always false
                        [-Werror,-Wtautological-constant-out-of-range-compare]
                        if (val >= (uint64_t)UINT_MAX * 1000 / HZ) {

As the check remains useful for other configurations, shut up the
warning by adding a second type cast to uint64_t.

Fixes: 468dfca38b ("dm integrity: add a bitmap mode")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10 16:28:23 +02:00
Mikulas Patocka
3d47eb4057 dm snapshot: fix lockup in dm_exception_table_exit
[ Upstream commit 6e7132ed3c07bd8a6ce3db4bb307ef2852b322dc ]

There was reported lockup when we exit a snapshot with many exceptions.
Fix this by adding "cond_resched" to the loop that frees the exceptions.

Reported-by: John Pittman <jpittman@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03 15:19:39 +02:00
Yu Kuai
aab8a0745f dm-raid: fix lockdep waring in "pers->hot_add_disk"
[ Upstream commit 95009ae904b1e9dca8db6f649f2d7c18a6e42c75 ]

The lockdep assert is added by commit a448af25becf ("md/raid10: remove
rcu protection to access rdev from conf") in print_conf(). And I didn't
notice that dm-raid is calling "pers->hot_add_disk" without holding
'reconfig_mutex'.

"pers->hot_add_disk" read and write many fields that is protected by
'reconfig_mutex', and raid_resume() already grab the lock in other
contex. Hence fix this problem by protecting "pers->host_add_disk"
with the lock.

Fixes: 9092c02d94 ("DM RAID: Add ability to restore transiently failed devices on resume")
Fixes: a448af25becf ("md/raid10: remove rcu protection to access rdev from conf")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240305072306.2562024-10-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03 15:19:31 +02:00
Gui-Dong Han
9477cfeb30 md/raid5: fix atomicity violation in raid5_cache_count
[ Upstream commit dfd2bf436709b2bccb78c2dda550dde93700efa7 ]

In raid5_cache_count():
    if (conf->max_nr_stripes < conf->min_nr_stripes)
        return 0;
    return conf->max_nr_stripes - conf->min_nr_stripes;
The current check is ineffective, as the values could change immediately
after being checked.

In raid5_set_cache_size():
    ...
    conf->min_nr_stripes = size;
    ...
    while (size > conf->max_nr_stripes)
        conf->min_nr_stripes = conf->max_nr_stripes;
    ...

Due to intermediate value updates in raid5_set_cache_size(), concurrent
execution of raid5_cache_count() and raid5_set_cache_size() may lead to
inconsistent reads of conf->max_nr_stripes and conf->min_nr_stripes.
The current checks are ineffective as values could change immediately
after being checked, raising the risk of conf->min_nr_stripes exceeding
conf->max_nr_stripes and potentially causing an integer overflow.

This possible bug is found by an experimental static analysis tool
developed by our team. This tool analyzes the locking APIs to extract
function pairs that can be concurrently executed, and then analyzes the
instructions in the paired functions to identify possible concurrency bugs
including data races and atomicity violations. The above possible bug is
reported when our tool analyzes the source code of Linux 6.2.

To resolve this issue, it is suggested to introduce local variables
'min_stripes' and 'max_stripes' in raid5_cache_count() to ensure the
values remain stable throughout the check. Adding locks in
raid5_cache_count() fails to resolve atomicity violations, as
raid5_set_cache_size() may hold intermediate values of
conf->min_nr_stripes while unlocked. With this patch applied, our tool no
longer reports the bug, with the kernel configuration allyesconfig for
x86_64. Due to the lack of associated hardware, we cannot test the patch
in runtime testing, and just verify it according to the code logic.

Fixes: edbe83ab4c ("md/raid5: allow the stripe_cache to grow and shrink.")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <2045gemini@gmail.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240112071017.16313-1-2045gemini@gmail.com
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03 15:19:28 +02:00
Mikulas Patocka
aa587257e1 dm-integrity: align the outgoing bio in integrity_recheck
[ Upstream commit b4d78cfeb30476239cf08f4f40afc095c173d6e3 ]

It is possible to set up dm-integrity with smaller sector size than
the logical sector size of the underlying device. In this situation,
dm-integrity guarantees that the outgoing bios have the same alignment as
incoming bios (so, if you create a filesystem with 4k block size,
dm-integrity would send 4k-aligned bios to the underlying device).

This guarantee was broken when integrity_recheck was implemented.
integrity_recheck sends bio that is aligned to ic->sectors_per_block. So
if we set up integrity with 512-byte sector size on a device with logical
block size 4k, we would be sending unaligned bio. This triggered a bug in
one of our internal tests.

This commit fixes it by determining the actual alignment of the
incoming bio and then makes sure that the outgoing bio in
integrity_recheck has the same alignment.

Fixes: c88f5e553fe3 ("dm-integrity: recheck the integrity tag after a failure")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:21:03 -04:00
Hongyu Jin
92b3c2437d dm io: Support IO priority
[ Upstream commit 6e5f0f6383b4896c7e9b943d84b136149d0f45e9 ]

Some IO will dispatch from kworker with different io_context settings
than the submitting task, we may need to specify a priority to avoid
losing priority.

Add IO priority parameter to dm_io() and update all callers.

Co-developed-by: Yibin Ding <yibin.ding@unisoc.com>
Signed-off-by: Yibin Ding <yibin.ding@unisoc.com>
Signed-off-by: Hongyu Jin <hongyu.jin@unisoc.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Stable-dep-of: b4d78cfeb304 ("dm-integrity: align the outgoing bio in integrity_recheck")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:21:02 -04:00
Heinz Mauelshagen
d0980ed818 dm: address indent/space issues
[ Upstream commit 255e2646496fcbf836a3dfe1b535692f09f11b45 ]

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Stable-dep-of: b4d78cfeb304 ("dm-integrity: align the outgoing bio in integrity_recheck")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:21:02 -04:00
Mikulas Patocka
20e21c3c01 dm-integrity: fix a memory leak when rechecking the data
[ Upstream commit 55e565c42dce81a4e49c13262d5bc4eb4c2e588a ]

Memory for the "checksums" pointer will leak if the data is rechecked
after checksum failure (because the associated kfree won't happen due
to 'goto skip_io').

Fix this by freeing the checksums memory before recheck, and just use
the "checksum_onstack" memory for storing checksum during recheck.

Fixes: c88f5e553fe3 ("dm-integrity: recheck the integrity tag after a failure")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:21:00 -04:00