diff options
| author | Chris Mason <chris.mason@oracle.com> | 2008-04-21 16:01:38 (GMT) |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2008-09-25 15:04:02 (GMT) |
| commit | 3c12ac7205d4bd679fefa722aa9b61385e4b4749 (patch) | |
| tree | 6582fba4c63ce451be7a338acb351cf17b9d766d /fs/btrfs/volumes.c | |
| parent | f2d8d74d7874f8f81222363cd6459a365796e35a (diff) | |
| download | linux-3c12ac7205d4bd679fefa722aa9b61385e4b4749.tar.xz | |
Btrfs: Simplify device selection for mirrored reads
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/volumes.c')
| -rw-r--r-- | fs/btrfs/volumes.c | 23 |
1 files changed, 7 insertions, 16 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 4602407..107fc74 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1029,19 +1029,8 @@ again: else if (mirror_num) { stripe_index = mirror_num - 1; } else { - int i; - u64 least = (u64)-1; - struct btrfs_device *cur; - - for (i = 0; i < map->num_stripes; i++) { - cur = map->stripes[i].dev; - spin_lock(&cur->io_lock); - if (cur->total_ios < least) { - least = cur->total_ios; - stripe_index = i; - } - spin_unlock(&cur->io_lock); - } + u64 orig_stripe_nr = stripe_nr; + stripe_index = do_div(orig_stripe_nr, num_stripes); } } else if (map->type & BTRFS_BLOCK_GROUP_DUP) { if (rw & (1 << BIO_RW)) @@ -1050,7 +1039,6 @@ again: stripe_index = mirror_num - 1; } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) { int factor = map->num_stripes / map->sub_stripes; - int orig_stripe_nr = stripe_nr; stripe_index = do_div(stripe_nr, factor); stripe_index *= map->sub_stripes; @@ -1059,8 +1047,11 @@ again: num_stripes = map->sub_stripes; else if (mirror_num) stripe_index += mirror_num - 1; - else - stripe_index += orig_stripe_nr % map->sub_stripes; + else { + u64 orig_stripe_nr = stripe_nr; + stripe_index += do_div(orig_stripe_nr, + map->sub_stripes); + } } else { /* * after this do_div call, stripe_nr is the number of stripes |