Commit 20a34a8e authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Alasdair G Kergon
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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: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent b09acf1a

drivers/md/dm-log.c

+22 −1
Original line number Diff line number Diff line
@@ -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 {

		if (lc->touched_dirtied) {

			r = flush_header(lc);

			if (r)

				fail_log_device(lc);

			else

				lc->touched_dirtied = 0;

		}

		lc->touched_cleaned = 0;

	}