[patch 10/47] ecryptfs: clean up (un)lock_parent

Greg KH
2008-06-14T00:15:42Z

[-- Attachment #1: ecryptfs-clean-up-lock_parent.patch --]
[-- Type: text/plain, Size: 1961 bytes --]

-stable review patch. If anyone has any objections, please let us know.

------------------
From: Miklos Szeredi <mszeredi@suse.cz>

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>
---
fs/ecryptfs/inode.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)

--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -37,17 +37,11 @@ static struct dentry *lock_parent(struct
{
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
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
dentry->d_inode->i_ctime = dir->i_ctime;
d_drop(dentry);
out_unlock:
- unlock_parent(lower_dentry);
+ unlock_dir(lower_dir_dentry);
return rc;
}

--