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| author | NeilBrown <neilb@suse.de> | 2007-01-26 00:57:11 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-01-26 13:51:00 -0800 |
| commit | 2a2275d630b982e5f90206f9bc497f6695a3ec5d (patch) | |
| tree | 88cddee709b2107b74e5424810d4ffb6e3772382 /drivers/md/raid1.c | |
| parent | a0ad13ef643a5829d63c456ab6143bbda60b44a9 (diff) | |
| download | linux-2a2275d630b982e5f90206f9bc497f6695a3ec5d.tar.gz linux-2a2275d630b982e5f90206f9bc497f6695a3ec5d.tar.bz2 linux-2a2275d630b982e5f90206f9bc497f6695a3ec5d.zip | |
[PATCH] md: fix potential memalloc deadlock in md
If a GFP_KERNEL allocation is attempted in md while the mddev_lock is held,
it is possible for a deadlock to eventuate.
This happens if the array was marked 'clean', and the memalloc triggers a
write-out to the md device.
For the writeout to succeed, the array must be marked 'dirty', and that
requires getting the mddev_lock.
So, before attempting a GFP_KERNEL allocation while holding the lock, make
sure the array is marked 'dirty' (unless it is currently read-only).
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/md/raid1.c')
| -rw-r--r-- | drivers/md/raid1.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index ab74d40cac98..97ee870b265d 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -2104,6 +2104,8 @@ static int raid1_reshape(mddev_t *mddev) return -EINVAL; } + md_allow_write(mddev); + raid_disks = mddev->raid_disks + mddev->delta_disks; if (raid_disks < conf->raid_disks) { |