Mike Snitzer aa6df8dd28 dm: fix free_rq_clone() NULL pointer when requeueing unmapped request ... Commit 022333427a ("dm: optimize dm_mq_queue_rq to _not_ use kthread if using pure blk-mq") mistakenly removed free_rq_clone()'s clone->q check before testing clone->q->mq_ops. It was an oversight to discontinue that check for 1 of the 2 use-cases for free_rq_clone(): 1) free_rq_clone() called when an unmapped original request is requeued 2) free_rq_clone() called in the request-based IO completion path The clone->q check made sense for case #1 but not for #2. However, we cannot just reinstate the check as it'd mask a serious bug in the IO completion case #2 -- no in-flight request should have an uninitialized request_queue (basic block layer refcounting _should_ ensure this). The NULL pointer seen for case #1 is detailed here: https://www.redhat.com/archives/dm-devel/2015-April/msg00160.html Fix this free_rq_clone() NULL pointer by simply checking if the mapped_device's type is DM_TYPE_MQ_REQUEST_BASED (clone's queue is blk-mq) rather than checking clone->q->mq_ops. This avoids the need to dereference clone->q, but a WARN_ON_ONCE is added to let us know if an uninitialized clone request is being completed. Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>		2015-04-30 10:25:21 -04:00
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bcache
persistent-data
bitmap.c
bitmap.h
dm-bio-prison.c
dm-bio-prison.h
dm-bio-record.h
dm-bufio.c
dm-bufio.h
dm-builtin.c
dm-cache-block-types.h
dm-cache-metadata.c
dm-cache-metadata.h
dm-cache-policy-cleaner.c
dm-cache-policy-internal.h
dm-cache-policy-mq.c
dm-cache-policy.c
dm-cache-policy.h
dm-cache-target.c
dm-crypt.c
dm-delay.c
dm-era-target.c
dm-exception-store.c
dm-exception-store.h
dm-flakey.c
dm-io.c
dm-ioctl.c
dm-kcopyd.c
dm-linear.c
dm-log-userspace-base.c
dm-log-userspace-transfer.c
dm-log-userspace-transfer.h
dm-log-writes.c
dm-log.c
dm-mpath.c
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-queue-length.c
dm-raid1.c
dm-raid.c
dm-region-hash.c
dm-round-robin.c
dm-service-time.c
dm-snap-persistent.c
dm-snap-transient.c
dm-snap.c
dm-stats.c
dm-stats.h
dm-stripe.c
dm-switch.c
dm-sysfs.c
dm-table.c
dm-target.c
dm-thin-metadata.c
dm-thin-metadata.h
dm-thin.c
dm-uevent.c
dm-uevent.h
dm-verity.c
dm-zero.c
dm.c	dm: fix free_rq_clone() NULL pointer when requeueing unmapped request	2015-04-30 10:25:21 -04:00
dm.h
faulty.c
Kconfig
linear.c
linear.h
Makefile
md-cluster.c
md-cluster.h
md.c
md.h
multipath.c
multipath.h
raid0.c
raid0.h
raid1.c
raid1.h
raid5.c
raid5.h
raid10.c
raid10.h