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| author | Shaohua Li <shli@fb.com> | 2015-09-02 22:49:49 +0200 |
|---|---|---|
| committer | NeilBrown <neilb@suse.com> | 2015-11-01 03:48:26 +0100 |
| commit | 828cbe989e4f5c8666cb3d99918b03666ccde0a0 (patch) | |
| tree | d0a2523905dbada0b75104e22e6b8d93fec77a78 /drivers/md/raid5-cache.c | |
| parent | raid5-cache: move functionality out of __r5l_set_io_unit_state (diff) | |
| download | linux-828cbe989e4f5c8666cb3d99918b03666ccde0a0.tar.xz linux-828cbe989e4f5c8666cb3d99918b03666ccde0a0.zip | |
raid5-cache: optimize FLUSH IO with log enabled
With log enabled, bio is written to raid disks after the bio is settled
down in log disk. The recovery guarantees we can recovery the bio data
from log disk, so we we skip FLUSH IO.
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Diffstat (limited to 'drivers/md/raid5-cache.c')
| -rw-r--r-- | drivers/md/raid5-cache.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 6479f15a5434..ea1480392eba 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -507,6 +507,24 @@ void r5l_write_stripe_run(struct r5l_log *log) mutex_unlock(&log->io_mutex); } +int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio) +{ + if (!log) + return -ENODEV; + /* + * we flush log disk cache first, then write stripe data to raid disks. + * So if bio is finished, the log disk cache is flushed already. The + * recovery guarantees we can recovery the bio from log disk, so we + * don't need to flush again + */ + if (bio->bi_iter.bi_size == 0) { + bio_endio(bio); + return 0; + } + bio->bi_rw &= ~REQ_FLUSH; + return -EAGAIN; +} + /* This will run after log space is reclaimed */ static void r5l_run_no_space_stripes(struct r5l_log *log) { |