RFC dm-raid1: fix deadlock at suspend after suspend was interrupted
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- v1 RFC Latest3 patches 4 repliesIn review
Patches in v1 No applies recorded yet
| # | Subject and files | Size | Replies | Applied |
|---|---|---|---|---|
| 1/3 | dm: introduce a presuspend cancel frameworkdrivers/ drivers/ drivers/ +1 more | +40 | 0 replies | |
| 2/3 | dm-raid1: add cancel_presuspend functiondrivers/ | +9 | 0 replies | |
| 3/3 | dm-delay: add cancel_presuspend functiondrivers/ | +1 | 0 replies |
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Cover letter [RFC][PATCH 0/3] dm-raid1: fix deadlock at suspend after suspend was interrupted
Hi,
This is a patch set to fix deadlock on suspending of mirror device.
ISSUE
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Suspend procedure on a dm-mirror device could cause deadlock on recovery_count semaphore.
When mirror_presuspend is called, recovery_count semaphore is acquired in dm_rh_stop_recovery() to stop recovery routine, but when an signal is caught in dm_wait_for_completion() or an error occurred in in dm_suspend(), the suspend process is interrupted without releasing recovery_count semaphore of a mirror device. This means that another suspend is executed, and then the suspend process gets stuck at dm_rh_stop_recovery().
When suspend procedure is interrupted, the device should work properly since the status of the device is not "suspended."
SOLUTION
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Introduce a target handler, cancel_presuspend, to cancel status changes done by a target specific presuspend handler.
PATCH SET
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1/3: dm: introduce cancel_presuspend framework 2/3: dm-raid1: add cancel_presuspend function 3/3: dm-delay: add cancel_presuspend function
I appreciate your comments.
Thanks,
Signature · 2 lines
Takahiro Yasui Hitachi Computer Products (America), Inc.