[PATCH 8/8] raid5-cache: add trim support for log
From: Shaohua Li <hidden>
Date: 2015-09-02 20:49:51
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
Since superblock is updated infrequently, we do a simple trim of log disk (a synchronous trim) Signed-off-by: Shaohua Li <redacted> --- drivers/md/raid5-cache.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-)
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 27fb513..410b85b 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c@@ -639,6 +639,34 @@ static void r5l_kick_io_unit(struct r5l_log *log) } static void r5l_write_super(struct r5l_log *log, sector_t cp); +static void r5l_write_super_and_discard_space(struct r5l_log *log, + sector_t end) +{ + struct block_device *bdev = log->rdev->bdev; + + r5l_write_super(log, end); + + if (!blk_queue_discard(bdev_get_queue(bdev))) + return; + + /* discard destroy old data in log, so force a super update */ + md_update_sb(log->rdev->mddev, 1); + + if (log->last_checkpoint < end) { + blkdev_issue_discard(bdev, + log->last_checkpoint + log->rdev->data_offset, + end - log->last_checkpoint, GFP_NOIO, 0); + } else { + blkdev_issue_discard(bdev, + log->last_checkpoint + log->rdev->data_offset, + log->device_size - log->last_checkpoint, + GFP_NOIO, 0); + blkdev_issue_discard(bdev, log->rdev->data_offset, end, + GFP_NOIO, 0); + } +} + + static void r5l_do_reclaim(struct r5l_log *log) { struct r5l_io_unit *io, *last;
@@ -694,7 +722,7 @@ static void r5l_do_reclaim(struct r5l_log *log) * here, because the log area might be reused soon and we don't want to * confuse recovery * */ - r5l_write_super(log, last->log_start); + r5l_write_super_and_discard_space(log, last->log_start); mutex_lock(&log->io_mutex); log->last_checkpoint = last->log_start;
--
1.8.1