linux/drivers/md
Mikulas Patocka 32a926da5a dm: always hold bdev reference
Fix a potential deadlock when creating multiple snapshots by holding a
reference to struct block_device for the whole lifecycle of every dm
device instead of obtaining it independently at each point it is needed.

bdget_disk() was called while the device was being suspended, in
dm_suspend().  However there could be other devices already suspended,
for example when creating additional snapshots of a device. bdget_disk()
can wait for IO and allocate memory resulting in waiting for the
already-suspended device - deadlock.

This patch changes the code so that it gets the reference to struct
block_device when struct mapped_device is allocated and initialized in
alloc_dev() where it is always OK to allocate memory or wait for I/O.
It drops the reference when it is destroyed in free_dev().  Thus there
is no call to bdget_disk() while any device is suspended.

Previously unlock_fs() was called only if bdev was held.  Now it is
called unconditionally, but the superfluous calls are harmless because
it returns immediately if the filesystem was not previously frozen.

This patch also now allows the device size to be changed in a
noflush suspend because the bdev is held.  This has no adverse effect.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:17 +01:00
..
raid6test md/raid6: move raid6 data processing to raid6_pq.ko 2009-03-31 15:09:39 +11:00
.gitignore
bitmap.c Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block 2009-06-11 11:10:35 -07:00
bitmap.h md: move headers out of include/linux/raid/ 2009-03-31 14:27:03 +11:00
dm-bio-record.h dm: preserve bi_io_vec when resubmitting bios 2009-04-02 19:55:23 +01:00
dm-crypt.c dm crypt: use kzfree 2009-04-02 19:55:28 +01:00
dm-delay.c block: move bio list helpers into bio.h 2009-04-15 08:28:09 +02:00
dm-exception-store.c dm exception store: fix exstore lookup to be case insensitive 2009-06-22 10:12:15 +01:00
dm-exception-store.h dm: use i_size_read 2009-06-22 10:12:14 +01:00
dm-io.c dm io: make sync_io uninterruptible 2009-04-02 19:55:24 +01:00
dm-ioctl.c Driver Core: misc: add nodename support for misc devices. 2009-06-15 21:30:25 -07:00
dm-kcopyd.c dm kcopyd: fix callback race 2009-04-09 00:27:17 +01:00
dm-linear.c dm: remove limited barrier support 2009-04-09 00:27:13 +01:00
dm-log.c dm: use i_size_read 2009-06-22 10:12:14 +01:00
dm-mpath.c dm mpath: flush keventd queue in destructor 2009-06-22 10:12:13 +01:00
dm-mpath.h dm mpath: remove is_active from struct dm_path 2008-10-10 13:36:58 +01:00
dm-path-selector.c dm: path selector use module refcount directly 2009-04-02 19:55:27 +01:00
dm-path-selector.h [PATCH] struct path: rename DM's struct path 2006-12-08 08:28:40 -08:00
dm-raid1.c block: move bio list helpers into bio.h 2009-04-15 08:28:09 +02:00
dm-region-hash.c dm raid1: keep retrying alloc if mempool_alloc failed 2009-06-22 10:12:13 +01:00
dm-round-robin.c dm: remove dm header from targets 2008-10-21 17:44:59 +01:00
dm-snap-persistent.c block: Do away with the notion of hardsect_size 2009-05-22 23:22:54 +02:00
dm-snap-transient.c dm snapshot: move status to exception store 2009-04-02 19:55:35 +01:00
dm-snap.c block: move bio list helpers into bio.h 2009-04-15 08:28:09 +02:00
dm-stripe.c dm: consolidate target deregistration error handling 2009-01-06 03:04:58 +00:00
dm-sysfs.c dm: add name and uuid to sysfs 2009-01-06 03:05:12 +00:00
dm-table.c dm: use i_size_read 2009-06-22 10:12:14 +01:00
dm-target.c dm target: remove struct tt_internal 2009-04-02 19:55:28 +01:00
dm-uevent.c md: replace remaining __FUNCTION__ occurrences 2008-04-28 08:58:42 -07:00
dm-uevent.h dm: uevent generate events 2007-10-20 02:01:26 +01:00
dm-zero.c dm: consolidate target deregistration error handling 2009-01-06 03:04:58 +00:00
dm.c dm: always hold bdev reference 2009-06-22 10:12:17 +01:00
dm.h dm: remove limited barrier support 2009-04-09 00:27:13 +01:00
faulty.c md: Move check for bitmap presence to personality code. 2009-06-18 08:49:23 +10:00
Kconfig md: remove CONFIG_MD_RAID_RESHAPE config option. 2009-03-31 15:27:05 +11:00
linear.c md/linear: use call_rcu to free obsolete 'conf' structures. 2009-06-18 08:49:42 +10:00
linear.h md/linear: use call_rcu to free obsolete 'conf' structures. 2009-06-18 08:49:42 +10:00
Makefile md/raid6: move raid6 data processing to raid6_pq.ko 2009-03-31 15:09:39 +11:00
md.c md: Move check for bitmap presence to personality code. 2009-06-18 08:49:23 +10:00
md.h md: Move check for bitmap presence to personality code. 2009-06-18 08:49:23 +10:00
mktables.c md/raid6: move raid6 data processing to raid6_pq.ko 2009-03-31 15:09:39 +11:00
multipath.c md: Move check for bitmap presence to personality code. 2009-06-18 08:49:23 +10:00
multipath.h md: remove mddev_to_conf "helper" macro 2009-06-16 16:54:21 +10:00
raid0.c md: Move check for bitmap presence to personality code. 2009-06-18 08:49:23 +10:00
raid0.h md: remove mddev_to_conf "helper" macro 2009-06-16 16:54:21 +10:00
raid1.c md: Push down reconstruction log message to personality code. 2009-06-18 08:48:06 +10:00
raid1.h md: remove mddev_to_conf "helper" macro 2009-06-16 16:54:21 +10:00
raid5.c md/raid5: correctly update sync_completed when we reach max_resync 2009-06-18 09:14:12 +10:00
raid5.h md: convert conf->chunk_size and conf->prev_chunk to sectors. 2009-06-18 08:45:55 +10:00
raid6algos.c md/raid6: move raid6 data processing to raid6_pq.ko 2009-03-31 15:09:39 +11:00
raid6altivec.uc md/raid6: move raid6 data processing to raid6_pq.ko 2009-03-31 15:09:39 +11:00
raid6int.uc md/raid6: move raid6 data processing to raid6_pq.ko 2009-03-31 15:09:39 +11:00
raid6mmx.c md/raid6: move raid6 data processing to raid6_pq.ko 2009-03-31 15:09:39 +11:00
raid6recov.c md/raid6: move raid6 data processing to raid6_pq.ko 2009-03-31 15:09:39 +11:00
raid6sse1.c md/raid6: move raid6 data processing to raid6_pq.ko 2009-03-31 15:09:39 +11:00
raid6sse2.c md/raid6: move raid6 data processing to raid6_pq.ko 2009-03-31 15:09:39 +11:00
raid6x86.h md: fix typo in FSF address 2009-03-31 14:57:37 +11:00
raid10.c md: Push down reconstruction log message to personality code. 2009-06-18 08:48:06 +10:00
raid10.h md: remove mddev_to_conf "helper" macro 2009-06-16 16:54:21 +10:00
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