diff options
Diffstat (limited to 'sys/kern/vfs_lockf.c')
| -rw-r--r-- | sys/kern/vfs_lockf.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/sys/kern/vfs_lockf.c b/sys/kern/vfs_lockf.c index b01a869708d..ed63facb48d 100644 --- a/sys/kern/vfs_lockf.c +++ b/sys/kern/vfs_lockf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: vfs_lockf.c,v 1.10 2005/03/10 17:26:10 tedu Exp $ */ +/* $OpenBSD: vfs_lockf.c,v 1.11 2005/03/15 03:47:58 tedu Exp $ */ /* $NetBSD: vfs_lockf.c,v 1.7 1996/02/04 02:18:21 christos Exp $ */ /* @@ -86,9 +86,18 @@ void lf_free(struct lockf *); * We enforce a limit on locks by uid, so that a single user cannot * run the kernel out of memory. For now, the limit is pretty coarse. * There is no limit on root. + * + * Splitting a lock will always succeed, regardless of current allocations. + * If you're slightly above the limit, we still have to permit an allocation + * so that the unlock can succeed. If the unlocking causes too many splits, + * however, you're totally cutoff. */ int maxlocksperuid = 1024; +/* + * 3 options for allowfail. + * 0 - always allocate. 1 - cutoff at limit. 2 - cutoff at double limit. + */ struct lockf * lf_alloc(uid_t uid, int allowfail) { @@ -96,13 +105,15 @@ lf_alloc(uid_t uid, int allowfail) struct lockf *lock; uip = uid_find(uid); - if (uid && allowfail && uip->ui_lockcnt > maxlocksperuid) + if (uid && allowfail && uip->ui_lockcnt > + (allowfail == 1 ? maxlocksperuid : (maxlocksperuid * 2))) return (NULL); uip->ui_lockcnt++; lock = pool_get(&lockfpool, PR_WAITOK); lock->lf_uid = uid; return (lock); } + void lf_free(struct lockf *lock) { @@ -175,7 +186,7 @@ lf_advlock(head, size, id, op, fl, flags) /* * Create the lockf structure. */ - lock = lf_alloc(p->p_ucred->cr_uid, op != F_UNLCK); + lock = lf_alloc(p->p_ucred->cr_uid, op != F_UNLCK ? 1 : 2); if (!lock) return (ENOMEM); lock->lf_start = start; |