1 files changed, 13 insertions, 5 deletions

diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 7fdd184a528..cbba000dccb 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -60,15 +60,20 @@ static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
                 return ERR_PTR(-EINVAL);
         }
 
+        /* Handle the cached NULL acl case without locking */
+        acl = ACCESS_ONCE(*p_acl);
+        if (!acl)
+                return acl;
+
         spin_lock(&inode->i_lock);
-        if (*p_acl != BTRFS_ACL_NOT_CACHED)
-                acl = posix_acl_dup(*p_acl);
+        acl = *p_acl;
+        if (acl != BTRFS_ACL_NOT_CACHED)
+                acl = posix_acl_dup(acl);
         spin_unlock(&inode->i_lock);
 
-        if (acl)
+        if (acl != BTRFS_ACL_NOT_CACHED)
                 return acl;
 
-
         size = __btrfs_getxattr(inode, name, "", 0);
         if (size > 0) {
                 value = kzalloc(size, GFP_NOFS);
@@ -80,9 +85,12 @@ static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
                         btrfs_update_cached_acl(inode, p_acl, acl);
                 }
                 kfree(value);
-        } else if (size == -ENOENT) {
+        } else if (size == -ENOENT || size == -ENODATA || size == 0) {
+                /* FIXME, who returns -ENOENT?  I think nobody */
                 acl = NULL;
                 btrfs_update_cached_acl(inode, p_acl, acl);
+        } else {
+                acl = ERR_PTR(-EIO);
         }
 
         return acl;