linux/drivers/md
Mikulas Patocka 3b6b7813b1 dm verity: avoid deadlock
A deadlock was found in the prefetch code in the dm verity map
function.  This patch fixes this by transferring the prefetch
to a worker thread and skipping it completely if kmalloc fails.

If generic_make_request is called recursively, it queues the I/O
request on the current->bio_list without making the I/O request
and returns. The routine making the recursive call cannot wait
for the I/O to complete.

The deadlock occurs when one thread grabs the bufio_client
mutex and waits for an I/O to complete but the I/O is queued
on another thread's current->bio_list and is waiting to get
the mutex held by the first thread.

The fix recognises that prefetching is not essential.  If memory
can be allocated, it queues the prefetch request to the worker thread,
but if not, it does nothing.

Signed-off-by: Paul Taysom <taysom@chromium.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
2013-03-20 17:21:25 +00:00
..
persistent-data dm thin: fix discard corruption 2013-03-20 17:21:24 +00:00
bitmap.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
bitmap.h md/bitmap: record the space available for the bitmap in the superblock. 2012-05-22 13:55:34 +10:00
dm-bio-prison.c dm: add cache target 2013-03-01 22:45:51 +00:00
dm-bio-prison.h dm: add cache target 2013-03-01 22:45:51 +00:00
dm-bio-record.h
dm-bufio.c dm verity: avoid deadlock 2013-03-20 17:21:25 +00:00
dm-bufio.h dm bufio: prefetch 2012-03-28 18:41:29 +01:00
dm-cache-block-types.h dm: add cache target 2013-03-01 22:45:51 +00:00
dm-cache-metadata.c dm: add cache target 2013-03-01 22:45:51 +00:00
dm-cache-metadata.h dm: add cache target 2013-03-01 22:45:51 +00:00
dm-cache-policy-cleaner.c dm cache: add cleaner policy 2013-03-01 22:45:52 +00:00
dm-cache-policy-internal.h dm: add cache target 2013-03-01 22:45:51 +00:00
dm-cache-policy-mq.c dm cache: add mq policy 2013-03-01 22:45:51 +00:00
dm-cache-policy.c dm: add cache target 2013-03-01 22:45:51 +00:00
dm-cache-policy.h dm: add cache target 2013-03-01 22:45:51 +00:00
dm-cache-target.c dm: add cache target 2013-03-01 22:45:51 +00:00
dm-crypt.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-delay.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-exception-store.c dm: replace simple_strtoul 2012-07-27 15:07:59 +01:00
dm-exception-store.h
dm-flakey.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-io.c dm kcopyd: add WRITE SAME support to dm_kcopyd_zero 2012-12-21 20:23:37 +00:00
dm-ioctl.c dm ioctl: allow message to return data 2013-03-01 22:45:49 +00:00
dm-kcopyd.c dm kcopyd: introduce configurable throttling 2013-03-01 22:45:49 +00:00
dm-linear.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-log-userspace-base.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
dm-log-userspace-transfer.c connector/userns: replace netlink uses of cap_raised() with capable() 2012-05-10 23:21:39 -04:00
dm-log-userspace-transfer.h
dm-log.c dm: use memweight() 2012-07-30 17:25:16 -07:00
dm-mpath.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-mpath.h
dm-path-selector.c md: Add module.h to all files using it implicitly 2011-10-31 19:31:18 -04:00
dm-path-selector.h
dm-queue-length.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-raid1.c dm kcopyd: introduce configurable throttling 2013-03-01 22:45:49 +00:00
dm-raid.c md updates for 3.9 2013-03-05 17:22:08 -08:00
dm-region-hash.c dm raid1: fix crash with mirror recovery and discard 2012-07-20 14:25:03 +01:00
dm-round-robin.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-service-time.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-snap-persistent.c md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
dm-snap-transient.c md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
dm-snap.c dm kcopyd: introduce configurable throttling 2013-03-01 22:45:49 +00:00
dm-stripe.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-sysfs.c
dm-table.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-target.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-thin-metadata.c dm persistent data: set some btree fn parms const 2013-03-01 22:45:47 +00:00
dm-thin-metadata.h dm thin metadata: introduce dm_pool_abort_metadata 2012-07-27 15:08:15 +01:00
dm-thin.c dm thin: fix non power of two discard granularity calc 2013-03-20 17:21:25 +00:00
dm-uevent.c md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
dm-uevent.h
dm-verity.c dm verity: avoid deadlock 2013-03-20 17:21:25 +00:00
dm-zero.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm.c dm: add target num_write_bios fn 2013-03-01 22:45:49 +00:00
dm.h dm: introduce per_bio_data 2012-12-21 20:23:38 +00:00
faulty.c md faulty: use disk_stack_limits() 2012-10-22 10:44:55 +11:00
Kconfig md updates for 3.9 2013-03-05 17:22:08 -08:00
linear.c md: linear supports TRIM 2012-10-11 13:08:44 +11:00
linear.h md/linear: typedef removal: linear_conf_t -> struct linear_conf 2011-10-11 16:48:54 +11:00
Makefile dm cache: add cleaner policy 2013-03-01 22:45:52 +00:00
md.c md: expedite metadata update when switching read-auto -> active 2013-02-28 11:59:03 +11:00
md.h md update for 3.8 2012-12-18 09:32:44 -08:00
multipath.c MD: change the parameter of md thread 2012-10-11 13:34:00 +11:00
multipath.h md/multipath: typedef removal: multipath_conf_t -> struct mpconf 2011-10-11 16:48:57 +11:00
raid0.c md/raid0: improve error message when converting RAID4-with-spares to RAID0 2013-02-26 11:58:44 +11:00
raid0.h md: add proper merge_bvec handling to RAID0 and Linear. 2012-03-19 12:46:39 +11:00
raid1.c md/raid1,raid10: fix deadlock with freeze_array() 2013-02-26 11:58:50 +11:00
raid1.h md/raid1: prevent merging too large request 2012-07-31 10:03:53 +10:00
raid5.c md updates for 3.9 2013-03-05 17:22:08 -08:00
raid5.h MD: raid5 trim support 2012-10-11 13:49:05 +11:00
raid10.c md/raid1,raid10: fix deadlock with freeze_array() 2013-02-26 11:58:50 +11:00
raid10.h MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1) 2013-02-26 11:55:30 +11:00