From 848cce0d4102b5b4b26b0987b43e1919d462afe2 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 21 Feb 2012 17:04:28 +0800 Subject: [PATCH] Btrfs: avoid setting ->d_op twice Follow those instructions, and you'll trigger a warning in the beginning of d_set_d_op(): # mkfs.btrfs /dev/loop3 # mount /dev/loop3 /mnt # btrfs sub create /mnt/sub # btrfs sub snap /mnt /mnt/snap # touch /mnt/snap/sub touch: cannot touch `tmp': Permission denied __d_alloc() set d_op to sb->s_d_op (btrfs_dentry_operations), and then simple_lookup() reset it to simple_dentry_operations, which triggered the warning. Signed-off-by: Li Zefan --- fs/btrfs/inode.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 1be31368e881..a682c267576d 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4069,7 +4069,7 @@ static struct inode *new_simple_dir(struct super_block *s, BTRFS_I(inode)->dummy_inode = 1; inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; - inode->i_op = &simple_dir_inode_operations; + inode->i_op = &btrfs_dir_ro_inode_operations; inode->i_fop = &simple_dir_operations; inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; @@ -4140,14 +4140,18 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) static int btrfs_dentry_delete(const struct dentry *dentry) { struct btrfs_root *root; + struct inode *inode = dentry->d_inode; - if (!dentry->d_inode && !IS_ROOT(dentry)) - dentry = dentry->d_parent; + if (!inode && !IS_ROOT(dentry)) + inode = dentry->d_parent->d_inode; - if (dentry->d_inode) { - root = BTRFS_I(dentry->d_inode)->root; + if (inode) { + root = BTRFS_I(inode)->root; if (btrfs_root_refs(&root->root_item) == 0) return 1; + + if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) + return 1; } return 0; }