diff options
| author | Joe Thornber <ejt@redhat.com> | 2014-10-10 15:27:16 +0100 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2014-11-10 15:25:28 -0500 |
| commit | 2d759a46b4d65e1392843cf9df7101897af87008 (patch) | |
| tree | 7cca57c04d5d8e29ca7ae232fa52f2e8fa6883c3 /drivers/md/dm-bio-prison.h | |
| parent | a374bb217b449a00eb96d0584bb833a8b62b672a (diff) | |
dm thin: remap the bios in a cell immediately
This use of direct submission in process_prepared_mapping() reduces
latency for submitting bios in a cell by avoiding adding those bios to
the deferred list and waiting for the next iteration of the worker.
But this direct submission exposes the potential for a race between
releasing a cell and incrementing deferred set. Fix this by introducing
dm_cell_visit_release() and refactoring inc_remap_and_issue_cell()
accordingly.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-bio-prison.h')
| -rw-r--r-- | drivers/md/dm-bio-prison.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/md/dm-bio-prison.h b/drivers/md/dm-bio-prison.h index c0cddb118582..b03988667740 100644 --- a/drivers/md/dm-bio-prison.h +++ b/drivers/md/dm-bio-prison.h @@ -89,6 +89,14 @@ void dm_cell_release_no_holder(struct dm_bio_prison *prison, void dm_cell_error(struct dm_bio_prison *prison, struct dm_bio_prison_cell *cell, int error); +/* + * Visits the cell and then releases. Guarantees no new inmates are + * inserted between the visit and release. + */ +void dm_cell_visit_release(struct dm_bio_prison *prison, + void (*visit_fn)(void *, struct dm_bio_prison_cell *), + void *context, struct dm_bio_prison_cell *cell); + /*----------------------------------------------------------------*/ /* |