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: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 13e2a1a..691cb9c 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -326,8 +326,6 @@
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 @@
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 @@
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 @@
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 @@
/* 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 @@
if (!lc->touched)
return 0;
- r = write_header(lc);
+ r = rw_header(lc, WRITE);
if (r)
fail_log_device(lc);
else