Date: Sat, 4 Jul 1998 14:58:11 -0700 (PDT) From: Julian Elischer <julian@whistle.com> To: current@FreeBSD.ORG Subject: small locking patch for discussion Message-ID: <Pine.BSF.3.95.980704145503.10069F-200000@current1.whistle.com>
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[-- Attachment #1 --]
I have this litle patch sitting around.
I don't know if it does anything but could someone who
knows about the locking comment?
It was a "BTW" from terry and I'd like to either
commit it or throw it away, rather than have it
sitting there looking at me..
julian
[-- Attachment #2 --]
Index: ufs/ufs/ufs_quota.c
===================================================================
RCS file: /home/ncvs/src/sys/ufs/ufs/ufs_quota.c,v
retrieving revision 1.23
diff -c -r1.23 ufs_quota.c
*** ufs_quota.c 1998/06/21 14:53:40 1.23
--- ufs_quota.c 1998/07/04 20:39:16
***************
*** 465,478 ****
/*
* Search vnodes associated with this mount point,
* deleting any references to quota file being closed.
*/
again:
for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nextvp) {
nextvp = vp->v_mntvnodes.le_next;
if (vp->v_type == VNON)
continue;
! if (vget(vp, LK_EXCLUSIVE, p))
goto again;
ip = VTOI(vp);
dq = ip->i_dquot[type];
ip->i_dquot[type] = NODQUOT;
--- 465,489 ----
/*
* Search vnodes associated with this mount point,
* deleting any references to quota file being closed.
+ *
+ * This is nearly identical to code in VFSOP_RELOAD, and
+ * *must* be maintained in parallel!
*/
again:
+ simple_lock(&mntvnode_slock);
for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nextvp) {
+ if (vp->v_mount != mp) {
+ simple_unlock(&mntvnode_slock);
+ goto again;
+ }
nextvp = vp->v_mntvnodes.le_next;
if (vp->v_type == VNON)
continue;
! simple_lock(&vp->v_interlock);
! simple_unlock(&mntvnode_slock);
! if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p)) {
goto again;
+ }
ip = VTOI(vp);
dq = ip->i_dquot[type];
ip->i_dquot[type] = NODQUOT;
***************
*** 480,485 ****
--- 491,497 ----
vput(vp);
if (vp->v_mntvnodes.le_next != nextvp || vp->v_mount != mp)
goto again;
+ simple_lock(&mntvnode_slock);
}
dqflush(qvp);
qvp->v_flag &= ~VSYSTEM;
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