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authorLi Zefan <lizf@cn.fujitsu.com>2011-03-28 02:01:25 +0000
committerChris Mason <chris.mason@oracle.com>2011-04-05 01:20:24 -0400
commit08fe4db170b4193603d9d31f40ebaf652d07ac9c (patch)
tree2d0d2abe40b77266600653e399d4973a679716a9 /fs/btrfs/disk-io.c
parentadae52b94e18afa1f84fab67df2a8a872c2f5533 (diff)
Btrfs: Fix uninitialized root flags for subvolumes
root_item->flags and root_item->byte_limit are not initialized when a subvolume is created. This bug is not revealed until we added readonly snapshot support - now you mount a btrfs filesystem and you may find the subvolumes in it are readonly. To work around this problem, we steal a bit from root_item->inode_item->flags, and use it to indicate if those fields have been properly initialized. When we read a tree root from disk, we check if the bit is set, and if not we'll set the flag and initialize the two fields of the root item. Reported-by: Andreas Philipp <philipp.andreas@gmail.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Tested-by: Andreas Philipp <philipp.andreas@gmail.com> cc: stable@kernel.org Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
-rw-r--r--fs/btrfs/disk-io.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 5cf3aa7b125..a272bfd74ea 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1276,8 +1276,10 @@ struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
root->commit_root = btrfs_root_node(root);
BUG_ON(!root->node);
out:
- if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
+ if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
root->ref_cows = 1;
+ btrfs_check_and_init_root_item(&root->root_item);
+ }
return root;
}