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nfs: dont unhash target if renaming a directory

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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@suse.cz>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Miklos Szeredi 2009-12-03 15:58:56 -05:00 committed by Trond Myklebust
parent 28f79a1a69
commit 27226104e6
1 changed files with 29 additions and 27 deletions
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56
fs/nfs/dir.c
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@ -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;
}
}
/*