From 27226104e60964f21717e0f452cecd45c85a64c6 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 3 Dec 2009 15:58:56 -0500 Subject: [PATCH] nfs: dont unhash target if renaming a directory Move unhashing the target to after the check for existence and being a non-directory. If renaming a directory then the VFS already unhashes the target if it is not busy. If it's busy then acquiring more references during the rename makes no difference. Signed-off-by: Miklos Szeredi Signed-off-by: Trond Myklebust --- fs/nfs/dir.c | 56 +++++++++++++++++++++++++++------------------------- 1 file changed, 29 insertions(+), 27 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 11d0c4cffffc..76b7f539d76e 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1579,15 +1579,6 @@ static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, struct dentry *dentry = NULL, *rehash = NULL; int error = -EBUSY; - /* - * To prevent any new references to the target during the rename, - * we unhash the dentry in advance. - */ - if (!d_unhashed(new_dentry)) { - d_drop(new_dentry); - rehash = new_dentry; - } - dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n", old_dentry->d_parent->d_name.name, old_dentry->d_name.name, new_dentry->d_parent->d_name.name, new_dentry->d_name.name, @@ -1599,25 +1590,36 @@ static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, * silly-rename succeeds, the copied dentry is hashed and becomes * the new target. */ - if (new_inode && !S_ISDIR(new_inode->i_mode) && - atomic_read(&new_dentry->d_count) > 2) { - int err; - /* copy the target dentry's name */ - dentry = d_alloc(new_dentry->d_parent, - &new_dentry->d_name); - if (!dentry) - goto out; + if (new_inode && !S_ISDIR(new_inode->i_mode)) { + /* + * To prevent any new references to the target during the + * rename, we unhash the dentry in advance. + */ + if (!d_unhashed(new_dentry)) { + d_drop(new_dentry); + rehash = new_dentry; + } - /* silly-rename the existing target ... */ - err = nfs_sillyrename(new_dir, new_dentry); - if (!err) { - new_dentry = rehash = dentry; - new_inode = NULL; - /* instantiate the replacement target */ - d_instantiate(new_dentry, NULL); - } else if (atomic_read(&new_dentry->d_count) > 1) - /* dentry still busy? */ - goto out; + if (atomic_read(&new_dentry->d_count) > 2) { + int err; + + /* copy the target dentry's name */ + dentry = d_alloc(new_dentry->d_parent, + &new_dentry->d_name); + if (!dentry) + goto out; + + /* silly-rename the existing target ... */ + err = nfs_sillyrename(new_dir, new_dentry); + if (!err) { + new_dentry = rehash = dentry; + new_inode = NULL; + /* instantiate the replacement target */ + d_instantiate(new_dentry, NULL); + } else if (atomic_read(&new_dentry->d_count) > 1) + /* dentry still busy? */ + goto out; + } } /* -- 2.39.2