From fe64171b1f483e1d70414ec4e149247b38376744 Mon Sep 17 00:00:00 2001
From: Stefan Behrens <sbehrens@giantdisaster.de>
Date: Tue, 6 Nov 2012 14:16:24 +0100
Subject: [PATCH] --- yaml --- r: 346695 b: refs/heads/master c:
 29a8d9a0bce6a5abac1f313400c2e189e8d10e67 h: refs/heads/master i:   346693:
 561e8603955a99463cb3a7621b49b5d0340d8dac   346691:
 596ad086c718677cb98bd42af77e3926b9d63d69   346687:
 bd58ddfc65ddbb3f9881fe1e3c12a447e183e883 v: v3

---
 [refs]                   | 2 +-
 trunk/fs/btrfs/ctree.h   | 3 +++
 trunk/fs/btrfs/reada.c   | 3 ++-
 trunk/fs/btrfs/scrub.c   | 4 ++--
 trunk/fs/btrfs/volumes.c | 8 ++++----
 5 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/[refs] b/[refs]
index f2aa9f20c354..28d169f582d8 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8dabb7420f014ab0f9f04afae8ae046c0f48b270
+refs/heads/master: 29a8d9a0bce6a5abac1f313400c2e189e8d10e67
diff --git a/trunk/fs/btrfs/ctree.h b/trunk/fs/btrfs/ctree.h
index 45e7f752b64a..46bd7d5f504b 100644
--- a/trunk/fs/btrfs/ctree.h
+++ b/trunk/fs/btrfs/ctree.h
@@ -174,6 +174,9 @@ static int btrfs_csum_sizes[] = { 4, 0 };
 /* four bytes for CRC32 */
 #define BTRFS_EMPTY_DIR_SIZE 0
 
+/* spefic to btrfs_map_block(), therefore not in include/linux/blk_types.h */
+#define REQ_GET_READ_MIRRORS	(1 << 30)
+
 #define BTRFS_FT_UNKNOWN	0
 #define BTRFS_FT_REG_FILE	1
 #define BTRFS_FT_DIR		2
diff --git a/trunk/fs/btrfs/reada.c b/trunk/fs/btrfs/reada.c
index c705a48e676b..96b93daa0bbb 100644
--- a/trunk/fs/btrfs/reada.c
+++ b/trunk/fs/btrfs/reada.c
@@ -359,7 +359,8 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root,
 	 * map block
 	 */
 	length = blocksize;
-	ret = btrfs_map_block(fs_info, REQ_WRITE, logical, &length, &bbio, 0);
+	ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical, &length,
+			      &bbio, 0);
 	if (ret || !bbio || length < blocksize)
 		goto error;
 
diff --git a/trunk/fs/btrfs/scrub.c b/trunk/fs/btrfs/scrub.c
index 30cbf6921c0b..30ba99724896 100644
--- a/trunk/fs/btrfs/scrub.c
+++ b/trunk/fs/btrfs/scrub.c
@@ -1193,8 +1193,8 @@ static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
 		 * with a length of PAGE_SIZE, each returned stripe
 		 * represents one mirror
 		 */
-		ret = btrfs_map_block(fs_info, WRITE, logical, &mapped_length,
-				      &bbio, 0);
+		ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical,
+				      &mapped_length, &bbio, 0);
 		if (ret || !bbio || mapped_length < sublen) {
 			kfree(bbio);
 			return -EIO;
diff --git a/trunk/fs/btrfs/volumes.c b/trunk/fs/btrfs/volumes.c
index a4e0963bf457..de0c05cca390 100644
--- a/trunk/fs/btrfs/volumes.c
+++ b/trunk/fs/btrfs/volumes.c
@@ -4103,7 +4103,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 					    stripe_nr_end - stripe_nr_orig);
 		stripe_index = do_div(stripe_nr, map->num_stripes);
 	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
-		if (rw & (REQ_WRITE | REQ_DISCARD))
+		if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
 			num_stripes = map->num_stripes;
 		else if (mirror_num)
 			stripe_index = mirror_num - 1;
@@ -4115,7 +4115,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 		}
 
 	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
-		if (rw & (REQ_WRITE | REQ_DISCARD)) {
+		if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
 			num_stripes = map->num_stripes;
 		} else if (mirror_num) {
 			stripe_index = mirror_num - 1;
@@ -4129,7 +4129,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 		stripe_index = do_div(stripe_nr, factor);
 		stripe_index *= map->sub_stripes;
 
-		if (rw & REQ_WRITE)
+		if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
 			num_stripes = map->sub_stripes;
 		else if (rw & REQ_DISCARD)
 			num_stripes = min_t(u64, map->sub_stripes *
@@ -4242,7 +4242,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
 		}
 	}
 
-	if (rw & REQ_WRITE) {
+	if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
 		if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
 				 BTRFS_BLOCK_GROUP_RAID10 |
 				 BTRFS_BLOCK_GROUP_DUP)) {