Mikulas Patocka 340cd44451 dm kcopyd: fix callback race ... If the thread calling dm_kcopyd_copy is delayed due to scheduling inside split_job/segment_complete and the subjobs complete before the loop in split_job completes, the kcopyd callback could be invoked from the thread that called dm_kcopyd_copy instead of the kcopyd workqueue. dm_kcopyd_copy -> split_job -> segment_complete -> job->fn() Snapshots depend on the fact that callbacks are called from the singlethreaded kcopyd workqueue and expect that there is no racing between individual callbacks. The racing between callbacks can lead to corruption of exception store and it can also mean that exception store callbacks are called twice for the same exception - a likely reason for crashes reported inside pending_complete() / remove_exception(). This patch fixes two problems: 1. job->fn being called from the thread that submitted the job (see above). - Fix: hand over the completion callback to the kcopyd thread. 2. job->fn(read_err, write_err, job->context); in segment_complete reports the error of the last subjob, not the union of all errors. - Fix: pass job->write_err to the callback to report all error bits (it is done already in run_complete_job) Cc: stable@kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>		2009-04-09 00:27:17 +01:00
..
raid6test
.gitignore
bitmap.c
bitmap.h
dm-bio-list.h
dm-bio-record.h
dm-crypt.c
dm-delay.c
dm-exception-store.c
dm-exception-store.h
dm-io.c
dm-ioctl.c
dm-kcopyd.c
dm-linear.c
dm-log.c
dm-mpath.c
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-raid1.c
dm-region-hash.c
dm-round-robin.c
dm-snap-persistent.c
dm-snap-transient.c
dm-snap.c
dm-stripe.c
dm-sysfs.c
dm-table.c
dm-target.c
dm-uevent.c
dm-uevent.h
dm-zero.c
dm.c
dm.h
faulty.c
Kconfig
linear.c
linear.h
Makefile
md.c
md.h
mktables.c
multipath.c
multipath.h
raid0.c
raid0.h
raid1.c
raid1.h
raid5.c
raid5.h
raid6algos.c
raid6altivec.uc
raid6int.uc
raid6mmx.c
raid6recov.c
raid6sse1.c
raid6sse2.c
raid6x86.h
raid10.c
raid10.h
unroll.pl