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>

diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 24eb0d37241a1f5e6dec78732eb7c7296f14a738..72d4d004282617dcd50d2c1b9c26e72ded745638 100644 (file)
--- 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;