From cc7539edea6dd02536d56f0a3405b8bb7ae24168 Mon Sep 17 00:00:00 2001 From: Zhao Lei Date: Tue, 20 Jan 2015 15:11:32 +0800 Subject: [PATCH] Btrfs: sort raid_map before adding tgtdev stripes It can avoid complex calculation of real stripes in sort, moreover, we can clean up code of sorting tgtdev_map because it will be in order initially. Signed-off-by: Zhao Lei Signed-off-by: Miao Xie Signed-off-by: Chris Mason --- fs/btrfs/volumes.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 0d9bfebdaa4c..711ce38543a1 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4876,18 +4876,17 @@ static inline int parity_smaller(u64 a, u64 b) } /* Bubble-sort the stripe set to put the parity/syndrome stripes last */ -static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map) +static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map, + int num_stripes) { struct btrfs_bio_stripe s; - int real_stripes = bbio->num_stripes - bbio->num_tgtdevs; int i; u64 l; int again = 1; - int m; while (again) { again = 0; - for (i = 0; i < real_stripes - 1; i++) { + for (i = 0; i < num_stripes - 1; i++) { if (parity_smaller(raid_map[i], raid_map[i+1])) { s = bbio->stripes[i]; l = raid_map[i]; @@ -4896,13 +4895,6 @@ static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map) bbio->stripes[i+1] = s; raid_map[i+1] = l; - if (bbio->tgtdev_map) { - m = bbio->tgtdev_map[i]; - bbio->tgtdev_map[i] = - bbio->tgtdev_map[i + 1]; - bbio->tgtdev_map[i + 1] = m; - } - again = 1; } } @@ -5340,6 +5332,9 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) max_errors = btrfs_chunk_max_errors(map); + if (raid_map) + sort_parity_stripes(bbio, raid_map, num_stripes); + tgtdev_indexes = 0; if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) && dev_replace->tgtdev != NULL) { @@ -5443,10 +5438,9 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, bbio->stripes[0].physical = physical_to_patch_in_first_stripe; bbio->mirror_num = map->num_stripes + 1; } - if (raid_map) { - sort_parity_stripes(bbio, raid_map); + + if (raid_map_ret) *raid_map_ret = raid_map; - } out: if (dev_replace_is_ongoing) btrfs_dev_replace_unlock(dev_replace); -- 2.20.1