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| author |  Yu Kuai <yukuai3@huawei.com>
| 2024-04-22 14:58:24 +0800 |
|---|---|---|
| committer |  Song Liu <song@kernel.org>
| 2024-05-02 14:44:43 -0700 |
| commit | f0e729af2eb6bee9eb58c4df1087f14ebaefe26b (patch) | |
| tree | 448b7839a73e90703153c9d70af212da2ecf9a3d /drivers/md | |
| parent | md: don't account sync_io if iostats of the disk is disabled (diff) | |
| download | linux-f0e729af2eb6bee9eb58c4df1087f14ebaefe26b.tar.gz linux-f0e729af2eb6bee9eb58c4df1087f14ebaefe26b.tar.bz2 linux-f0e729af2eb6bee9eb58c4df1087f14ebaefe26b.zip | |
md: fix resync softlockup when bitmap size is less than array size
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>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/md-bitmap.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index 059afc24c08b..0a2d37eb38ef 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -1424,7 +1424,7 @@ __acquires(bitmap->lock) sector_t chunk = offset >> bitmap->chunkshift; unsigned long page = chunk >> PAGE_COUNTER_SHIFT; unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT; - sector_t csize; + sector_t csize = ((sector_t)1) << bitmap->chunkshift; int err; if (page >= bitmap->pages) { @@ -1433,6 +1433,7 @@ __acquires(bitmap->lock) * End-of-device while looking for a whole page or * user set a huge number to sysfs bitmap_set_bits. */ + *blocks = csize - (offset & (csize - 1)); return NULL; } err = md_bitmap_checkpage(bitmap, page, create, 0); @@ -1441,8 +1442,7 @@ __acquires(bitmap->lock) bitmap->bp[page].map == NULL) csize = ((sector_t)1) << (bitmap->chunkshift + PAGE_COUNTER_SHIFT); - else - csize = ((sector_t)1) << bitmap->chunkshift; + *blocks = csize - (offset & (csize - 1)); if (err < 0) |