bfa152fa5e
Allow noflush suspend/resume of device-mapper device only for the case where the device size is unchanged. Otherwise, dm-multipath devices can stall when resumed if noflush was used when suspending them, all paths have failed and queue_if_no_path is set. Explanation: 1. Something is doing fsync() on the block dev, holding inode->i_sem 2. The fsync write is blocked by all-paths-down and queue_if_no_path 3. Someone requests to suspend the dm device with noflush. Pending writes are left in queue. 4. In the middle of dm_resume(), __bind() tries to get inode->i_sem to do __set_size() and waits forever. 'noflush suspend' is a new device-mapper feature introduced in early 2.6.20. So I hope the fix being included before 2.6.20 is released. Example of reproducer: 1. Create a multipath device by dmsetup 2. Fail all paths during mkfs 3. Do dmsetup suspend --noflush and load new map with healthy paths 4. Do dmsetup resume Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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.. | ||
raid6test | ||
.gitignore | ||
bitmap.c | ||
dm-bio-list.h | ||
dm-bio-record.h | ||
dm-crypt.c | ||
dm-emc.c | ||
dm-exception-store.c | ||
dm-hw-handler.c | ||
dm-hw-handler.h | ||
dm-io.c | ||
dm-io.h | ||
dm-ioctl.c | ||
dm-linear.c | ||
dm-log.c | ||
dm-log.h | ||
dm-mpath.c | ||
dm-mpath.h | ||
dm-path-selector.c | ||
dm-path-selector.h | ||
dm-raid1.c | ||
dm-round-robin.c | ||
dm-snap.c | ||
dm-snap.h | ||
dm-stripe.c | ||
dm-table.c | ||
dm-target.c | ||
dm-zero.c | ||
dm.c | ||
dm.h | ||
faulty.c | ||
Kconfig | ||
kcopyd.c | ||
kcopyd.h | ||
linear.c | ||
Makefile | ||
md.c | ||
mktables.c | ||
multipath.c | ||
raid0.c | ||
raid1.c | ||
raid5.c | ||
raid6.h | ||
raid6algos.c | ||
raid6altivec.uc | ||
raid6int.uc | ||
raid6mmx.c | ||
raid6recov.c | ||
raid6sse1.c | ||
raid6sse2.c | ||
raid6x86.h | ||
raid10.c | ||
unroll.pl | ||
xor.c |