svn commit: r268384 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Tue Jul  8 08:10:15 2014
New Revision: 268384
URL: http://svnweb.freebsd.org/changeset/base/268384

Log:
  Correct the problem reported by test16 from
  tools/regression/file/flock/flock.c, which completes the fix in
  r192685.  When the lock was stolen from us, retry the whole lock
  sequence in kernel, instead of returning EINTR to usermode and hoping
  that application would handle it correctly by restarting the lock
  acquire.
  
  Tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	2 weeks

Modified:
  head/sys/kern/kern_lockf.c

Modified: head/sys/kern/kern_lockf.c
==============================================================================
--- head/sys/kern/kern_lockf.c	Tue Jul  8 08:05:42 2014	(r268383)
+++ head/sys/kern/kern_lockf.c	Tue Jul  8 08:10:15 2014	(r268384)
@@ -469,6 +469,9 @@ lf_advlockasync(struct vop_advlockasync_
 			return (EOVERFLOW);
 		end = start + oadd;
 	}
+
+retry_setlock:
+
 	/*
 	 * Avoid the common case of unlocking when inode has no locks.
 	 */
@@ -744,6 +747,11 @@ lf_advlockasync(struct vop_advlockasync_
 		sx_destroy(&freestate->ls_lock);
 		free(freestate, M_LOCKF);
 	}
+
+	if (error == EDOOFUS) {
+		KASSERT(ap->a_op == F_SETLK, ("EDOOFUS"));
+		goto retry_setlock;
+	}
 	return (error);
 }
 
@@ -1459,7 +1467,7 @@ lf_setlock(struct lockf *state, struct l
 		lock->lf_refs++;
 		error = sx_sleep(lock, &state->ls_lock, priority, lockstr, 0);
 		if (lf_free_lock(lock)) {
-			error = EINTR;
+			error = EDOOFUS;
 			goto out;
 		}