NFS: nfs4_lookup_revalidate: only evaluate parent if it will be used.
nfs4_lookup_revalidate only uses 'parent' to get 'dir', and only
uses 'dir' if 'inode == NULL'.
So we don't need to find out what 'parent' or 'dir' is until we
know that 'inode' is NULL.
By moving 'dget_parent' inside the 'if', we can reduce the number of
call sites for 'dput(parent)'.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 7dc88bb..0090dae 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1529,9 +1529,7 @@
static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags)
{
- struct dentry *parent = NULL;
struct inode *inode;
- struct inode *dir;
int ret = 0;
if (flags & LOOKUP_RCU)
@@ -1545,34 +1543,35 @@
goto no_open;
inode = dentry->d_inode;
- parent = dget_parent(dentry);
- dir = parent->d_inode;
/* We can't create new files in nfs_open_revalidate(), so we
* optimize away revalidation of negative dentries.
*/
if (inode == NULL) {
+ struct dentry *parent;
+ struct inode *dir;
+
+ parent = dget_parent(dentry);
+ dir = parent->d_inode;
if (!nfs_neg_need_reval(dir, dentry, flags))
ret = 1;
+ dput(parent);
goto out;
}
/* NFS only supports OPEN on regular files */
if (!S_ISREG(inode->i_mode))
- goto no_open_dput;
+ goto no_open;
/* We cannot do exclusive creation on a positive dentry */
if (flags & LOOKUP_EXCL)
- goto no_open_dput;
+ goto no_open;
/* Let f_op->open() actually open (and revalidate) the file */
ret = 1;
out:
- dput(parent);
return ret;
-no_open_dput:
- dput(parent);
no_open:
return nfs_lookup_revalidate(dentry, flags);
}