Btrfs: search parity device wisely

After mapping block with BTRFS_MAP_WRITE, parities have been sorted to
the end position, so this search can start from the first parity
stripe.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copied changelog as a comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Liu Bo 2017-08-03 13:53:31 -06:00 committed by David Sterba
parent ee87cf5ed9
commit 9cd3a7eb85

View File

@ -2231,12 +2231,18 @@ raid56_parity_alloc_scrub_rbio(struct btrfs_fs_info *fs_info, struct bio *bio,
ASSERT(!bio->bi_iter.bi_size);
rbio->operation = BTRFS_RBIO_PARITY_SCRUB;
for (i = 0; i < rbio->real_stripes; i++) {
/*
* After mapping bbio with BTRFS_MAP_WRITE, parities have been sorted
* to the end position, so this search can start from the first parity
* stripe.
*/
for (i = rbio->nr_data; i < rbio->real_stripes; i++) {
if (bbio->stripes[i].dev == scrub_dev) {
rbio->scrubp = i;
break;
}
}
ASSERT(i < rbio->real_stripes);
/* Now we just support the sectorsize equals to page size */
ASSERT(fs_info->sectorsize == PAGE_SIZE);