1 files changed, 64 insertions, 0 deletions
diff --git a/meta/recipes-devtools/btrfs-tools/btrfs-tools/upstream-for-dragonn/0001-Fill-missing-devices-so-degraded-filesystems-can-be-.patch b/meta/recipes-devtools/btrfs-tools/btrfs-tools/upstream-for-dragonn/0001-Fill-missing-devices-so-degraded-filesystems-can-be-.patch
new file mode 100644
index 0000000000..e4665335ee
--- /dev/null
+++ b/meta/recipes-devtools/btrfs-tools/btrfs-tools/upstream-for-dragonn/0001-Fill-missing-devices-so-degraded-filesystems-can-be-.patch
@@ -0,0 +1,64 @@
+Upstream-Status: Inappropriate [Backport]
+From a6c54702d8973aef081cff81ed8d90427bb21768 Mon Sep 17 00:00:00 2001
+From: Chris Mason <chris.mason@oracle.com>
+Date: Wed, 15 Dec 2010 16:00:23 -0500
+Subject: [PATCH 1/5] Fill missing devices so degraded filesystems can be read
+
+When a device is missing, the btrfs tools need to be able to read alternate
+copies from the remaining devices.  This creates placeholder devices
+that always return -EIO so the tools can limp along.
+
+Signed-off-by: Chris Mason <chris.mason@oracle.com>
+---
+ disk-io.c |    1 +
+ volumes.c |   15 +++++++++++++--
+ 2 files changed, 14 insertions(+), 2 deletions(-)
+
+diff --git a/disk-io.c b/disk-io.c
+index 5bd9cfc..f4368f3 100644
+--- a/disk-io.c
++++ b/disk-io.c
+@@ -204,6 +204,7 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
+ 		eb->dev_bytenr = multi->stripes[0].physical;
+ 		kfree(multi);
+ 		ret = read_extent_from_disk(eb);
++
+ 		if (ret == 0 && check_tree_block(root, eb) == 0 &&
+ 		    csum_tree_block(root, eb, 1) == 0 &&
+ 		    verify_parent_transid(eb->tree, eb, parent_transid) == 0) {
+diff --git a/volumes.c b/volumes.c
+index 4bb77e2..5773467 100644
+--- a/volumes.c
++++ b/volumes.c
+@@ -1263,6 +1263,16 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
+ 	return readonly;
+ }
+ 
++static struct btrfs_device *fill_missing_device(u64 devid)
++{
++	struct btrfs_device *device;
++
++	device = kzalloc(sizeof(*device), GFP_NOFS);
++	device->devid = devid;
++	device->fd = -1;
++	return device;
++}
++
+ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
+ 			  struct extent_buffer *leaf,
+ 			  struct btrfs_chunk *chunk)
+@@ -1313,8 +1323,9 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
+ 		map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
+ 							NULL);
+ 		if (!map->stripes[i].dev) {
+-			kfree(map);
+-			return -EIO;
++			map->stripes[i].dev = fill_missing_device(devid);
++			printf("warning, device %llu is missing\n",
++			       (unsigned long long)devid);
+ 		}
+ 
+ 	}
+-- 
+1.7.2.3
+