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| author | Alasdair G Kergon <agk@redhat.com> | 2005-07-12 15:53:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-07-12 16:19:10 -0700 |
| commit | 436d41087d047b61f8ab0604dc74fff3240a8933 (patch) | |
| tree | 46bab3a0cf02a7514b4faa5470a76326e6f8bc72 /drivers/md/dm.c | |
| parent | a044d016896d2717694003f00d31a98194077511 (diff) | |
| download | blackbird-op-linux-436d41087d047b61f8ab0604dc74fff3240a8933.tar.gz blackbird-op-linux-436d41087d047b61f8ab0604dc74fff3240a8933.zip | |
[PATCH] device-mapper multipath: Avoid possible suspension deadlock
To avoid deadlock when suspending a multipath device after all its paths have
failed, stop queueing any I/O that is about to fail *before* calling
freeze_bdev instead of after.
Instead of setting a multipath 'suspended' flag which would have to be reset
if an error occurs during the process, save the previous queueing state and
leave userspace to restore if it wishes.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/md/dm.c')
| -rw-r--r-- | drivers/md/dm.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 5d40555b42ba..bb3ad79c14d7 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1055,14 +1055,17 @@ int dm_suspend(struct mapped_device *md) if (test_bit(DMF_BLOCK_IO, &md->flags)) goto out_read_unlock; - error = __lock_fs(md); - if (error) - goto out_read_unlock; - map = dm_get_table(md); if (map) + /* This does not get reverted if there's an error later. */ dm_table_presuspend_targets(map); + error = __lock_fs(md); + if (error) { + dm_table_put(map); + goto out_read_unlock; + } + up_read(&md->lock); /* @@ -1121,7 +1124,6 @@ int dm_suspend(struct mapped_device *md) return 0; out_unfreeze: - /* FIXME Undo dm_table_presuspend_targets */ __unlock_fs(md); clear_bit(DMF_BLOCK_IO, &md->flags); out_write_unlock: |
