svn commit: r269166 - stable/10/sys/kern

[Konstantin Belousov]

Author: kib
Date: Mon Jul 28 00:57:28 2014
New Revision: 269166
URL: http://svnweb.freebsd.org/changeset/base/269166

Log:
  MFC r268607:
  In kern_linkat(), avoid passing doomed vnode to the VOP.

Modified:
  stable/10/sys/kern/vfs_syscalls.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/kern/vfs_syscalls.c
==============================================================================
--- stable/10/sys/kern/vfs_syscalls.c	Mon Jul 28 00:53:26 2014	(r269165)
+++ stable/10/sys/kern/vfs_syscalls.c	Mon Jul 28 00:57:28 2014	(r269166)
@@ -1555,6 +1555,7 @@ kern_linkat(struct thread *td, int fd1, 
 	bwillwrite();
 	NDINIT_AT(&nd, LOOKUP, follow | AUDITVNODE1, segflg, path1, fd1, td);
 
+again:
 	if ((error = namei(&nd)) != 0)
 		return (error);
 	NDFREE(&nd, NDF_ONLY_PNBUF);
@@ -1577,8 +1578,7 @@ kern_linkat(struct thread *td, int fd1, 
 				vput(nd.ni_dvp);
 			vrele(nd.ni_vp);
 			error = EEXIST;
-		} else if ((error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY))
-		    == 0) {
+		} else if ((error = vn_lock(vp, LK_EXCLUSIVE)) == 0) {
 			error = can_hardlink(vp, td->td_ucred);
 			if (error == 0)
 #ifdef MAC
@@ -1589,6 +1589,12 @@ kern_linkat(struct thread *td, int fd1, 
 				error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
 			VOP_UNLOCK(vp, 0);
 			vput(nd.ni_dvp);
+		} else {
+			vput(nd.ni_dvp);
+			NDFREE(&nd, NDF_ONLY_PNBUF);
+			vrele(vp);
+			vn_finished_write(mp);
+			goto again;
 		}
 		NDFREE(&nd, NDF_ONLY_PNBUF);
 	}