diff mbox

[v4,09/11] Btrfs: Set real mirror number for read operation on RAID0/5/6

Message ID 1410518644-31806-10-git-send-email-miaox@cn.fujitsu.com (mailing list archive)
State Accepted
Headers show

Commit Message

Miao Xie Sept. 12, 2014, 10:44 a.m. UTC 
We need real mirror number for RAID0/5/6 when reading data, or if read error
happens, we would pass 0 as the number of the mirror on which the io error
happens. It is wrong and would cause the filesystem read the data from the
corrupted mirror again.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
Changelog v1 -> v4:
- None
---
 fs/btrfs/volumes.c | 5 +++++
 1 file changed, 5 insertions(+)
diff mbox

Patch

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1aacf5f..4856547 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5073,6 +5073,8 @@  static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 			num_stripes = min_t(u64, map->num_stripes,
 					    stripe_nr_end - stripe_nr_orig);
 		stripe_index = do_div(stripe_nr, map->num_stripes);
+		if (!(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)))
+			mirror_num = 1;
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
 		if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
 			num_stripes = map->num_stripes;
@@ -5176,6 +5178,9 @@  static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 			/* We distribute the parity blocks across stripes */
 			tmp = stripe_nr + stripe_index;
 			stripe_index = do_div(tmp, map->num_stripes);
+			if (!(rw & (REQ_WRITE | REQ_DISCARD |
+				    REQ_GET_READ_MIRRORS)) && mirror_num <= 1)
+				mirror_num = 1;
 		}
 	} else {
 		/*