From 20a34a8ecc7d03eaa5054f58169ebff12f5f1f8c Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Thu, 10 Dec 2009 23:52:00 +0000 Subject: [PATCH] dm log: add flush_header function Introduce flush_header and use it to flush the log device. Note that we don't have to flush if all the regions transition from "dirty" to "clean" state. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- drivers/md/dm-log.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c index 31dc33df95c..6b23631db5b 100644 --- a/drivers/md/dm-log.c +++ b/drivers/md/dm-log.c @@ -288,6 +288,19 @@ static int rw_header(struct log_c *lc, int rw) return dm_io(&lc->io_req, 1, &lc->header_location, NULL); } +static int flush_header(struct log_c *lc) +{ + struct dm_io_region null_location = { + .bdev = lc->header_location.bdev, + .sector = 0, + .count = 0, + }; + + lc->io_req.bi_rw = WRITE_BARRIER; + + return dm_io(&lc->io_req, 1, &null_location, NULL); +} + static int read_header(struct log_c *log) { int r; @@ -616,6 +629,8 @@ static int disk_resume(struct dm_dirty_log *log) /* write the new header */ r = rw_header(lc, WRITE); + if (!r) + r = flush_header(lc); if (r) { DMWARN("%s: Failed to write header on dirty region log device", lc->log_dev->name); @@ -669,7 +684,13 @@ static int disk_flush(struct dm_dirty_log *log) if (r) fail_log_device(lc); else { - lc->touched_dirtied = 0; + if (lc->touched_dirtied) { + r = flush_header(lc); + if (r) + fail_log_device(lc); + else + lc->touched_dirtied = 0; + } lc->touched_cleaned = 0; } -- 2.20.1