diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2009-12-10 23:52:03 +0000 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2009-12-10 23:52:03 +0000 |
| commit | 04788507686d184d8166918b70ef52311bc36dcb (patch) | |
| tree | c17fb1f8f9ac8d2a137f9c523d059f5918940c93 /drivers/md/dm-raid1.c | |
| parent | 64b30c46e866bbff8a9e17883a18636adc358455 (diff) | |
dm raid1: add framework to hold bios during suspend
Add framework to delay bios until a suspend and then resubmit them with
either DM_ENDIO_REQUEUE (if the suspend was noflush) or complete them
with -EIO. I/O barrier support will use this.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/dm-raid1.c')
| -rw-r--r-- | drivers/md/dm-raid1.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index 85c8704c67b..895cce75eee 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -58,6 +58,7 @@ struct mirror_set { struct bio_list reads; struct bio_list writes; struct bio_list failures; + struct bio_list holds; /* bios are waiting until suspend */ struct dm_region_hash *rh; struct dm_kcopyd_client *kcopyd_client; @@ -450,6 +451,27 @@ static void map_region(struct dm_io_region *io, struct mirror *m, io->count = bio->bi_size >> 9; } +static void hold_bio(struct mirror_set *ms, struct bio *bio) +{ + /* + * If device is suspended, complete the bio. + */ + if (atomic_read(&ms->suspend)) { + if (dm_noflush_suspending(ms->ti)) + bio_endio(bio, DM_ENDIO_REQUEUE); + else + bio_endio(bio, -EIO); + return; + } + + /* + * Hold bio until the suspend is complete. + */ + spin_lock_irq(&ms->lock); + bio_list_add(&ms->holds, bio); + spin_unlock_irq(&ms->lock); +} + /*----------------------------------------------------------------- * Reads *---------------------------------------------------------------*/ @@ -1225,6 +1247,9 @@ static void mirror_presuspend(struct dm_target *ti) struct mirror_set *ms = (struct mirror_set *) ti->private; struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); + struct bio_list holds; + struct bio *bio; + atomic_set(&ms->suspend, 1); /* @@ -1247,6 +1272,22 @@ static void mirror_presuspend(struct dm_target *ti) * we know that all of our I/O has been pushed. */ flush_workqueue(ms->kmirrord_wq); + + /* + * Now set ms->suspend is set and the workqueue flushed, no more + * entries can be added to ms->hold list, so process it. + * + * Bios can still arrive concurrently with or after this + * presuspend function, but they cannot join the hold list + * because ms->suspend is set. + */ + spin_lock_irq(&ms->lock); + holds = ms->holds; + bio_list_init(&ms->holds); + spin_unlock_irq(&ms->lock); + + while ((bio = bio_list_pop(&holds))) + hold_bio(ms, bio); } static void mirror_postsuspend(struct dm_target *ti) |