1 files changed, 52 insertions, 26 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index fbe4ead..57a7f33 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5846,10 +5846,10 @@ struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
 }
 
 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
+					    struct btrfs_fs_devices *fs_devices,
 					    u64 devid, u8 *dev_uuid)
 {
 	struct btrfs_device *device;
-	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
 
 	device = btrfs_alloc_device(NULL, &devid, dev_uuid);
 	if (IS_ERR(device))
@@ -5986,7 +5986,8 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
 		}
 		if (!map->stripes[i].dev) {
 			map->stripes[i].dev =
-				add_missing_dev(root, devid, uuid);
+				add_missing_dev(root, root->fs_info->fs_devices,
+						devid, uuid);
 			if (!map->stripes[i].dev) {
 				free_extent_map(em);
 				return -EIO;
@@ -6027,7 +6028,8 @@ static void fill_device_from_item(struct extent_buffer *leaf,
 	read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
 }
 
-static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
+static struct btrfs_fs_devices *open_seed_devices(struct btrfs_root *root,
+						  u8 *fsid)
 {
 	struct btrfs_fs_devices *fs_devices;
 	int ret;
@@ -6036,49 +6038,56 @@ static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
 
 	fs_devices = root->fs_info->fs_devices->seed;
 	while (fs_devices) {
-		if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
-			ret = 0;
-			goto out;
-		}
+		if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE))
+			return fs_devices;
+
 		fs_devices = fs_devices->seed;
 	}
 
 	fs_devices = find_fsid(fsid);
 	if (!fs_devices) {
-		ret = -ENOENT;
-		goto out;
+		if (!btrfs_test_opt(root, DEGRADED))
+			return ERR_PTR(-ENOENT);
+
+		fs_devices = alloc_fs_devices(fsid);
+		if (IS_ERR(fs_devices))
+			return fs_devices;
+
+		fs_devices->seeding = 1;
+		fs_devices->opened = 1;
+		return fs_devices;
 	}
 
 	fs_devices = clone_fs_devices(fs_devices);
-	if (IS_ERR(fs_devices)) {
-		ret = PTR_ERR(fs_devices);
-		goto out;
-	}
+	if (IS_ERR(fs_devices))
+		return fs_devices;
 
 	ret = __btrfs_open_devices(fs_devices, FMODE_READ,
 				   root->fs_info->bdev_holder);
 	if (ret) {
 		free_fs_devices(fs_devices);
+		fs_devices = ERR_PTR(ret);
 		goto out;
 	}
 
 	if (!fs_devices->seeding) {
 		__btrfs_close_devices(fs_devices);
 		free_fs_devices(fs_devices);
-		ret = -EINVAL;
+		fs_devices = ERR_PTR(-EINVAL);
 		goto out;
 	}
 
 	fs_devices->seed = root->fs_info->fs_devices->seed;
 	root->fs_info->fs_devices->seed = fs_devices;
 out:
-	return ret;
+	return fs_devices;
 }
 
 static int read_one_dev(struct btrfs_root *root,
 			struct extent_buffer *leaf,
 			struct btrfs_dev_item *dev_item)
 {
+	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
 	struct btrfs_device *device;
 	u64 devid;
 	int ret;
@@ -6092,31 +6101,48 @@ static int read_one_dev(struct btrfs_root *root,
 			   BTRFS_UUID_SIZE);
 
 	if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
-		ret = open_seed_devices(root, fs_uuid);
-		if (ret && !(ret == -ENOENT && btrfs_test_opt(root, DEGRADED)))
-			return ret;
+		fs_devices = open_seed_devices(root, fs_uuid);
+		if (IS_ERR(fs_devices))
+			return PTR_ERR(fs_devices);
 	}
 
 	device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
-	if (!device || !device->bdev) {
+	if (!device) {
 		if (!btrfs_test_opt(root, DEGRADED))
 			return -EIO;
 
-		if (!device) {
-			btrfs_warn(root->fs_info, "devid %llu missing", devid);
-			device = add_missing_dev(root, devid, dev_uuid);
-			if (!device)
-				return -ENOMEM;
-		} else if (!device->missing) {
+		btrfs_warn(root->fs_info, "devid %llu missing", devid);
+		device = add_missing_dev(root, fs_devices, devid, dev_uuid);
+		if (!device)
+			return -ENOMEM;
+	} else {
+		if (!device->bdev && !btrfs_test_opt(root, DEGRADED))
+			return -EIO;
+
+		if(!device->bdev && !device->missing) {
 			/*
 			 * this happens when a device that was properly setup
 			 * in the device info lists suddenly goes bad.
 			 * device->bdev is NULL, and so we have to set
 			 * device->missing to one here
 			 */
-			root->fs_info->fs_devices->missing_devices++;
+			device->fs_devices->missing_devices++;
 			device->missing = 1;
 		}
+
+		/* Move the device to its own fs_devices */
+		if (device->fs_devices != fs_devices) {
+			ASSERT(device->missing);
+
+			list_move(&device->dev_list, &fs_devices->devices);
+			device->fs_devices->num_devices--;
+			fs_devices->num_devices++;
+
+			device->fs_devices->missing_devices--;
+			fs_devices->missing_devices++;
+
+			device->fs_devices = fs_devices;
+		}
 	}
 
 	if (device->fs_devices != root->fs_info->fs_devices) {