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authorNeilBrown <neilb@suse.de>2007-01-26 00:57:11 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-01-26 13:51:00 -0800
commit2a2275d630b982e5f90206f9bc497f6695a3ec5d (patch)
tree88cddee709b2107b74e5424810d4ffb6e3772382 /include
parenta0ad13ef643a5829d63c456ab6143bbda60b44a9 (diff)
[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 'include')
-rw-r--r--include/linux/raid/md.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/raid/md.h b/include/linux/raid/md.h
index 866a1e2b0ce0..fbaeda79b2e9 100644
--- a/include/linux/raid/md.h
+++ b/include/linux/raid/md.h
@@ -94,7 +94,7 @@ extern int sync_page_io(struct block_device *bdev, sector_t sector, int size,
struct page *page, int rw);
extern void md_do_sync(mddev_t *mddev);
extern void md_new_event(mddev_t *mddev);
-
+extern void md_allow_write(mddev_t *mddev);
#endif /* CONFIG_MD */
#endif