From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: [PATCH 1/2] btrfs: don't mess with i_nlink of unlocked inode in rename() Date: Fri, 4 Mar 2011 17:14:37 +0000 Message-ID: <20110304171437.GA26708@ZenIV.linux.org.uk> References: <20110304171353.GU22723@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org To: chris.mason@oracle.com Return-path: In-Reply-To: <20110304171353.GU22723@ZenIV.linux.org.uk> List-ID: old_inode is not locked; it's not safe to play with its link count. Instead of bumping it and calling btrfs_unlink_inode(), add a variant of the latter that does not do btrfs_drop_nlink()/ btrfs_update_inode(), call it instead of btrfs_inc_nlink()/ btrfs_unlink_inode() and do btrfs_update_inode() ourselves. Signed-off-by: Al Viro --- fs/btrfs/inode.c | 36 +++++++++++++++++++++++++----------- 1 files changed, 25 insertions(+), 11 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 0efdb65..099d64c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2634,10 +2634,10 @@ failed: * recovery code. It remove a link in a directory with a given name, and * also drops the back refs in the inode to the directory */ -int btrfs_unlink_inode(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct inode *dir, struct inode *inode, - const char *name, int name_len) +static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, struct inode *inode, + const char *name, int name_len) { struct btrfs_path *path; int ret = 0; @@ -2709,12 +2709,25 @@ err: btrfs_i_size_write(dir, dir->i_size - name_len * 2); inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; btrfs_update_inode(trans, root, dir); - btrfs_drop_nlink(inode); - ret = btrfs_update_inode(trans, root, inode); out: return ret; } +int btrfs_unlink_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, struct inode *inode, + const char *name, int name_len) +{ + int ret; + ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); + if (!ret) { + btrfs_drop_nlink(inode); + ret = btrfs_update_inode(trans, root, inode); + } + return ret; +} + + /* helper to check if there is any shared block in the path */ static int check_path_shared(struct btrfs_root *root, struct btrfs_path *path) @@ -6908,11 +6921,12 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, old_dentry->d_name.name, old_dentry->d_name.len); } else { - btrfs_inc_nlink(old_dentry->d_inode); - ret = btrfs_unlink_inode(trans, root, old_dir, - old_dentry->d_inode, - old_dentry->d_name.name, - old_dentry->d_name.len); + ret = __btrfs_unlink_inode(trans, root, old_dir, + old_dentry->d_inode, + old_dentry->d_name.name, + old_dentry->d_name.len); + if (!ret) + ret = btrfs_update_inode(trans, root, old_inode); } BUG_ON(ret); -- 1.7.2.5