[src/netbsd-1-4]: src/sys/ufs/lfs Pull up src/sys/ufs/lfs: lfs_alloc.c 1.19->...

[perseant <perseant%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0bdbfcbffbff
branches:  netbsd-1-4
changeset: 468300:0bdbfcbffbff
user:      perseant <perseant%NetBSD.org@localhost>
date:      Fri Apr 16 23:10:07 1999 +0000

description:
Pull up src/sys/ufs/lfs: lfs_alloc.c 1.19->1.21.

This fixes another locking problem, this time a lock on ufs_hashlock in
lfs_vfree.  The lock could be held by a process calling getnewvnode, and
then attempted again by lfs_vfree.  This works around that, not attempting
to get the lock if curproc already holds it.

diffstat:

 sys/ufs/lfs/lfs_alloc.c |  10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diffs (39 lines):

diff -r 51264416273a -r 0bdbfcbffbff sys/ufs/lfs/lfs_alloc.c
--- a/sys/ufs/lfs/lfs_alloc.c   Fri Apr 16 23:09:48 1999 +0000
+++ b/sys/ufs/lfs/lfs_alloc.c   Fri Apr 16 23:10:07 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: lfs_alloc.c,v 1.18.2.1 1999/04/13 21:33:55 perseant Exp $      */
+/*     $NetBSD: lfs_alloc.c,v 1.18.2.2 1999/04/16 23:10:07 perseant Exp $      */
 
 /*-
  * Copyright (c) 1999 The NetBSD Foundation, Inc.
@@ -292,15 +292,18 @@
        struct lfs *fs;
        ufs_daddr_t old_iaddr;
        ino_t ino;
+       int already_locked;
        
        /* Get the inode number and file system. */
        ip = VTOI(ap->a_pvp);
        fs = ip->i_lfs;
        ino = ip->i_number;
        
+       /* If we already hold ufs_hashlock, don't panic, just do it anyway */
+       already_locked = lockstatus(&ufs_hashlock) && ufs_hashlock.lk_lockholder == curproc->p_pid;
        while(WRITEINPROG(ap->a_pvp)
              || fs->lfs_seglock
-             || lockmgr(&ufs_hashlock, LK_EXCLUSIVE|LK_SLEEPFAIL, 0))
+             || (!already_locked && lockmgr(&ufs_hashlock, LK_EXCLUSIVE|LK_SLEEPFAIL, 0)))
        {
                if (WRITEINPROG(ap->a_pvp)) {
                        tsleep(ap->a_pvp, (PRIBIO+1), "lfs_vfree", 0);
@@ -357,7 +360,8 @@
                sup->su_nbytes -= DINODE_SIZE;
                (void) VOP_BWRITE(bp);
        }
-       lockmgr(&ufs_hashlock, LK_RELEASE, 0);
+       if(!already_locked)
+               lockmgr(&ufs_hashlock, LK_RELEASE, 0);
        
        /* Set superblock modified bit and decrement file count. */
        fs->lfs_fmod = 1;