diff options
Diffstat (limited to 'fs/btrfs/super.c')
| -rw-r--r-- | fs/btrfs/super.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 29eecbb6ec3a..5429b1fa0bfc 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -741,6 +741,16 @@ static int btrfs_set_super(struct super_block *s, void *data) } /* + * subvolumes are identified by ino 256 + */ +static inline int is_subvolume_inode(struct inode *inode) +{ + if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) + return 1; + return 0; +} + +/* * This will strip out the subvol=%s argument for an argument string and add * subvolid=0 to make sure we get the actual tree root for path walking to the * subvol we want. @@ -843,6 +853,15 @@ static struct dentry *mount_subvol(const char *subvol_name, int flags, if (error) return ERR_PTR(error); + if (!is_subvolume_inode(path.dentry->d_inode)) { + path_put(&path); + mntput(mnt); + error = -EINVAL; + printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n", + subvol_name); + return ERR_PTR(-EINVAL); + } + /* Get a ref to the sb and the dentry we found and return it */ s = path.mnt->mnt_sb; atomic_inc(&s->s_active); |