From 08fe4db170b4193603d9d31f40ebaf652d07ac9c Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 28 Mar 2011 02:01:25 +0000 Subject: 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 Signed-off-by: Li Zefan Tested-by: Andreas Philipp cc: stable@kernel.org Signed-off-by: Chris Mason --- fs/btrfs/ioctl.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/btrfs/ioctl.c') diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 255c7c5279c4..f9c93a9ed4a7 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -373,6 +373,10 @@ static noinline int create_subvol(struct btrfs_root *root, inode_item->nbytes = cpu_to_le64(root->leafsize); inode_item->mode = cpu_to_le32(S_IFDIR | 0755); + root_item.flags = 0; + root_item.byte_limit = 0; + inode_item->flags = cpu_to_le64(BTRFS_INODE_ROOT_ITEM_INIT); + btrfs_set_root_bytenr(&root_item, leaf->start); btrfs_set_root_generation(&root_item, trans->transid); btrfs_set_root_level(&root_item, 0); -- cgit v1.2.3