namei: results of d_is_negative() should be checked after dentry revalidation

[karo-tx-linux.git] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 29b927938b8ce9c78af99d0f9c8f5af5a294cefd..33e9495a31293e2c080b5b0bd2e50523a460ceee 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1558,8 +1558,6 @@ static int lookup_fast(struct nameidata *nd,
                negative = d_is_negative(dentry);
                if (read_seqcount_retry(&dentry->d_seq, seq))
                        return -ECHILD;
-               if (negative)
-                       return -ENOENT;
 
                /*
                 * This sequence count validates that the parent had no
@@ -1580,6 +1578,12 @@ static int lookup_fast(struct nameidata *nd,
                                goto unlazy;
                        }
                }
+               /*
+                * Note: do negative dentry check after revalidation in
+                * case that drops it.
+                */
+               if (negative)
+                       return -ENOENT;
                path->mnt = mnt;
                path->dentry = dentry;
                if (likely(__follow_mount_rcu(nd, path, inode, seqp)))
@@ -2438,7 +2442,7 @@ done:
 
 /**
  * path_mountpoint - look up a path to be umounted
- * @nameidata: lookup context
+ * @nd:                lookup context
  * @flags:     lookup flags
  * @path:      pointer to container for result
  *