From: Miklos Szeredi <mszeredi@xxxxxxx>
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 <mszeredi@xxxxxxx>
---
fs/nfs/dir.c | 58 ++++++++++++++++++++++++++++++----------------------------
1 file changed, 30 insertions(+), 28 deletions(-)
Index: linux-2.6/fs/nfs/dir.c
===================================================================
--- linux-2.6.orig/fs/nfs/dir.c 2009-12-02 15:10:44.000000000 +0100
+++ linux-2.6/fs/nfs/dir.c 2009-12-02 15:11:19.000000000 +0100
@@ -1579,15 +1579,6 @@ static int nfs_rename(struct inode *old_
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_
* 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;
-
- /* 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 (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;
+ }
+
+ 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;
+ }
}
/*
--
--
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