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author | Mike Snitzer <snitzer@redhat.com> | 2014-10-28 23:34:52 +0100 |
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committer | Mike Snitzer <snitzer@redhat.com> | 2014-11-19 18:31:17 +0100 |
commit | ffcc39364160663cda1a3c358f4537302a92459b (patch) | |
tree | bc7defa66e5c79b036ed21092a8005b72879559b /drivers/md/dm.h | |
parent | dm thin: do not allow thin device activation while pool is suspended (diff) | |
download | linux-ffcc39364160663cda1a3c358f4537302a92459b.tar.xz linux-ffcc39364160663cda1a3c358f4537302a92459b.zip |
dm: enhance internal suspend and resume interface
Rename dm_internal_{suspend,resume} to dm_internal_{suspend,resume}_fast
-- dm-stats will continue using these methods to avoid all the extra
suspend/resume logic that is not needed in order to quickly flush IO.
Introduce dm_internal_suspend_noflush() variant that actually calls the
mapped_device's target callbacks -- otherwise target-specific hooks are
avoided (e.g. dm-thin's thin_presuspend and thin_postsuspend). Common
code between dm_internal_{suspend_noflush,resume} and
dm_{suspend,resume} was factored out as __dm_{suspend,resume}.
Update dm_internal_{suspend_noflush,resume} to always take and release
the mapped_device's suspend_lock. Also update dm_{suspend,resume} to be
aware of potential for DM_INTERNAL_SUSPEND_FLAG to be set and respond
accordingly by interruptibly waiting for the DM_INTERNAL_SUSPEND_FLAG to
be cleared. Add lockdep annotation to dm_suspend() and dm_resume().
The existing DM_SUSPEND_FLAG remains unchanged.
DM_INTERNAL_SUSPEND_FLAG is set by dm_internal_suspend_noflush() and
cleared by dm_internal_resume().
Both DM_SUSPEND_FLAG and DM_INTERNAL_SUSPEND_FLAG may be set if a device
was already suspended when dm_internal_suspend_noflush() was called --
this can be thought of as a "nested suspend". A "nested suspend" can
occur with legacy userspace dm-thin code that might suspend all active
thin volumes before suspending the pool for resize.
But otherwise, in the normal dm-thin-pool suspend case moving forward:
the thin-pool will have DM_SUSPEND_FLAG set and all active thins from
that thin-pool will have DM_INTERNAL_SUSPEND_FLAG set.
Also add DM_INTERNAL_SUSPEND_FLAG to status report. This new
DM_INTERNAL_SUSPEND_FLAG state is being reported to assist with
debugging (e.g. 'dmsetup info' will report an internally suspended
device accordingly).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Diffstat (limited to 'drivers/md/dm.h')
-rw-r--r-- | drivers/md/dm.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/md/dm.h b/drivers/md/dm.h index 781994093bf5..84b0f9e4ba6c 100644 --- a/drivers/md/dm.h +++ b/drivers/md/dm.h @@ -130,6 +130,15 @@ int dm_deleting_md(struct mapped_device *md); int dm_suspended_md(struct mapped_device *md); /* + * Internal suspend and resume methods. + */ +int dm_suspended_internally_md(struct mapped_device *md); +void dm_internal_suspend_fast(struct mapped_device *md); +void dm_internal_resume_fast(struct mapped_device *md); +void dm_internal_suspend_noflush(struct mapped_device *md); +void dm_internal_resume(struct mapped_device *md); + +/* * Test if the device is scheduled for deferred remove. */ int dm_test_deferred_remove_flag(struct mapped_device *md); |