cachefiles: use path_get instead of lone dget

Dentry references should not be acquired without a corresponding
vfsmount ref.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 14 insertions, 12 deletions

diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 24eb0d37241a..72d4d0042826 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -553,7 +553,7 @@ static int cachefiles_daemon_tag(struct cachefiles_cache *cache, char *args)
 static int cachefiles_daemon_cull(struct cachefiles_cache *cache, char *args)
 {
         struct fs_struct *fs;
-        struct dentry *dir;
+        struct path path;
         const struct cred *saved_cred;
         int ret;
 
@@ -575,22 +575,23 @@ static int cachefiles_daemon_cull(struct cachefiles_cache *cache, char *args)
         /* extract the directory dentry from the cwd */
         fs = current->fs;
         read_lock(&fs->lock);
-        dir = dget(fs->pwd.dentry);
+        path = fs->pwd;
+        path_get(&path);
         read_unlock(&fs->lock);
 
-        if (!S_ISDIR(dir->d_inode->i_mode))
+        if (!S_ISDIR(path.dentry->d_inode->i_mode))
                 goto notdir;
 
         cachefiles_begin_secure(cache, &saved_cred);
-        ret = cachefiles_cull(cache, dir, args);
+        ret = cachefiles_cull(cache, path.dentry, args);
         cachefiles_end_secure(cache, saved_cred);
 
-        dput(dir);
+        path_put(&path);
         _leave(" = %d", ret);
         return ret;
 
 notdir:
-        dput(dir);
+        path_put(&path);
         kerror("cull command requires dirfd to be a directory");
         return -ENOTDIR;
 
@@ -629,7 +630,7 @@ inval:
 static int cachefiles_daemon_inuse(struct cachefiles_cache *cache, char *args)
 {
         struct fs_struct *fs;
-        struct dentry *dir;
+        struct path path;
         const struct cred *saved_cred;
         int ret;
 
@@ -651,22 +652,23 @@ static int cachefiles_daemon_inuse(struct cachefiles_cache *cache, char *args)
         /* extract the directory dentry from the cwd */
         fs = current->fs;
         read_lock(&fs->lock);
-        dir = dget(fs->pwd.dentry);
+        path = fs->pwd;
+        path_get(&path);
         read_unlock(&fs->lock);
 
-        if (!S_ISDIR(dir->d_inode->i_mode))
+        if (!S_ISDIR(path.dentry->d_inode->i_mode))
                 goto notdir;
 
         cachefiles_begin_secure(cache, &saved_cred);
-        ret = cachefiles_check_in_use(cache, dir, args);
+        ret = cachefiles_check_in_use(cache, path.dentry, args);
         cachefiles_end_secure(cache, saved_cred);
 
-        dput(dir);
+        path_put(&path);
         //_leave(" = %d", ret);
         return ret;
 
 notdir:
-        dput(dir);
+        path_put(&path);
         kerror("inuse command requires dirfd to be a directory");
         return -ENOTDIR;