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| author | Li Zefan <lizf@cn.fujitsu.com> | 2011-03-28 02:01:25 +0000 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2011-04-05 01:20:24 -0400 |
| commit | 08fe4db170b4193603d9d31f40ebaf652d07ac9c (patch) | |
| tree | 2d0d2abe40b77266600653e399d4973a679716a9 /fs/btrfs/disk-io.c | |
| parent | adae52b94e18afa1f84fab67df2a8a872c2f5533 (diff) | |
| download | lwn-08fe4db170b4193603d9d31f40ebaf652d07ac9c.tar.gz lwn-08fe4db170b4193603d9d31f40ebaf652d07ac9c.zip | |
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.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 5cf3aa7b125c..a272bfd74ea0 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; } |