ecryptfs: clean up (un)lock_parent

upstream commit: 8dc4e37362a5dc910d704d52ac6542bfd49ddc2f

dget(dentry->d_parent) --> dget_parent(dentry)

unlock_parent() is racy and unnecessary.  Replace single caller with
unlock_dir().

There are several other suspect uses of ->d_parent in ecryptfs...

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index af1b8c599fa554e114854721743b308d5f3bdf1a..a2174c270a6ef6fc63ccc6550d445a4cb5f698c3 100644 (file)
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -37,17 +37,11 @@ static struct dentry *lock_parent(struct dentry *dentry)
 {
        struct dentry *dir;
 
-       dir = dget(dentry->d_parent);
+       dir = dget_parent(dentry);
        mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
        return dir;
 }
 
-static void unlock_parent(struct dentry *dentry)
-{
-       mutex_unlock(&(dentry->d_parent->d_inode->i_mutex));
-       dput(dentry->d_parent);
-}
-
 static void unlock_dir(struct dentry *dir)
 {
        mutex_unlock(&dir->d_inode->i_mutex);
@@ -426,8 +420,9 @@ static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
        int rc = 0;
        struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
        struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
+       struct dentry *lower_dir_dentry;
 
-       lock_parent(lower_dentry);
+       lower_dir_dentry = lock_parent(lower_dentry);
        rc = vfs_unlink(lower_dir_inode, lower_dentry);
        if (rc) {
                printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
@@ -439,7 +434,7 @@ static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
        dentry->d_inode->i_ctime = dir->i_ctime;
        d_drop(dentry);
 out_unlock:
-       unlock_parent(lower_dentry);
+       unlock_dir(lower_dir_dentry);
        return rc;
 }