Commit 6f3af01c authored by Takahiro Yasui's avatar Takahiro Yasui Committed by Alasdair G Kergon
Browse files

dm log: avoid reinitialising io_req on every operation 



rw_header function updates three members of io_req data every time
when I/O is processed. bi_rw and notify.fn are never modified once
they get initialized, and so they can be set in advance.

header_to_disk() can also be pulled out of write_header() since only one
caller needs it and write_header() can be replaced by rw_header()
directly.

Signed-off-by: default avatarTakahiro Yasui <tyasui@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 10d3bd09

drivers/md/dm-log.c

+7 −10
Original line number Diff line number Diff line
@@ -326,8 +326,6 @@ static void header_from_disk(struct log_header *core, struct log_header *disk) 
static int rw_header(struct log_c *lc, int rw)

{

	lc->io_req.bi_rw = rw;

	lc->io_req.mem.ptr.vma = lc->disk_header;

	lc->io_req.notify.fn = NULL;



	return dm_io(&lc->io_req, 1, &lc->header_location, NULL);

}
@@ -362,12 +360,6 @@ static int read_header(struct log_c *log) 
	return 0;

}



static inline int write_header(struct log_c *log)

{

	header_to_disk(&log->header, log->disk_header);

	return rw_header(log, WRITE);

}



/*----------------------------------------------------------------

 * core log constructor/destructor

 *
@@ -454,7 +446,9 @@ static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti, 
		buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) +

				       bitset_size, ti->limits.hardsect_size);

		lc->header_location.count = buf_size >> SECTOR_SHIFT;



		lc->io_req.mem.type = DM_IO_VMA;

		lc->io_req.notify.fn = NULL;

		lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,

								   PAGE_SIZE));

		if (IS_ERR(lc->io_req.client)) {
@@ -472,6 +466,7 @@ static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti, 
			return -ENOMEM;

		}



		lc->io_req.mem.ptr.vma = lc->disk_header;

		lc->clean_bits = (void *)lc->disk_header +

				 (LOG_OFFSET << SECTOR_SHIFT);

	}
@@ -636,8 +631,10 @@ static int disk_resume(struct dm_dirty_log *log) 
	/* set the correct number of regions in the header */

	lc->header.nr_regions = lc->region_count;



	header_to_disk(&lc->header, lc->disk_header);



	/* write the new header */

	r = write_header(lc);

	r = rw_header(lc, WRITE);

	if (r) {

		DMWARN("%s: Failed to write header on dirty region log device",

		       lc->log_dev->name);
@@ -687,7 +684,7 @@ static int disk_flush(struct dm_dirty_log *log) 
	if (!lc->touched)

		return 0;



	r = write_header(lc);

	r = rw_header(lc, WRITE);

	if (r)

		fail_log_device(lc);

	else

CRA Git | Maintained and supported by SUSTech CRA and CCSE