Author: kib
Date: Thu Oct  3 19:55:05 2019
New Revision: 353065
URL: https://svnweb.freebsd.org/changeset/base/353065

Log:
  tmpfs_readdir(): unlock the locked node.
  
  During readdir() we guarantee that the tn_dir.tn_parent does not go
  away, but it might be replaced by a parallel rename.  Read tn_parent
  only once, then use the cached value.
  
  Reported and tested by:       pho
  Sponsored by: The FreeBSD Foundation
  MFC after:    1 week

Modified:
  head/sys/fs/tmpfs/tmpfs_subr.c

Modified: head/sys/fs/tmpfs/tmpfs_subr.c
==============================================================================
--- head/sys/fs/tmpfs/tmpfs_subr.c      Thu Oct  3 19:51:56 2019        
(r353064)
+++ head/sys/fs/tmpfs/tmpfs_subr.c      Thu Oct  3 19:55:05 2019        
(r353065)
@@ -1147,8 +1147,9 @@ static int
 tmpfs_dir_getdotdotdent(struct tmpfs_mount *tm, struct tmpfs_node *node,
     struct uio *uio)
 {
-       int error;
+       struct tmpfs_node *parent;
        struct dirent dent;
+       int error;
 
        TMPFS_VALIDATE_DIR(node);
        MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT);
@@ -1157,12 +1158,13 @@ tmpfs_dir_getdotdotdent(struct tmpfs_mount *tm, struct
         * Return ENOENT if the current node is already removed.
         */
        TMPFS_ASSERT_LOCKED(node);
-       if (node->tn_dir.tn_parent == NULL)
+       parent = node->tn_dir.tn_parent;
+       if (parent == NULL)
                return (ENOENT);
 
-       TMPFS_NODE_LOCK(node->tn_dir.tn_parent);
-       dent.d_fileno = node->tn_dir.tn_parent->tn_id;
-       TMPFS_NODE_UNLOCK(node->tn_dir.tn_parent);
+       TMPFS_NODE_LOCK(parent);
+       dent.d_fileno = parent->tn_id;
+       TMPFS_NODE_UNLOCK(parent);
 
        dent.d_type = DT_DIR;
        dent.d_namlen = 2;
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"

Reply via email to