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lockf: elide avoidable locking in lf_advlockasync

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While here assert on ls_threads state.
This commit is contained in:
Mateusz Guzik 2020-07-05 23:07:54 +00:00
parent 34fc29e0c9
commit d363fa4127
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=362950
1 changed files with 9 additions and 8 deletions
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17
sys/kern/kern_lockf.c
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@ -637,6 +637,7 @@ lf_advlockasync(struct vop_advlockasync_args *ap, struct lockf **statep,
VI_UNLOCK(vp); VI_UNLOCK(vp);
} else { } else {
state = *statep; state = *statep;
MPASS(state->ls_threads >= 0);
state->ls_threads++; state->ls_threads++;
VI_UNLOCK(vp); VI_UNLOCK(vp);
@ -647,6 +648,7 @@ lf_advlockasync(struct vop_advlockasync_args *ap, struct lockf **statep,
free(ls, M_LOCKF); free(ls, M_LOCKF);
} }
} else { } else {
MPASS(state->ls_threads >= 0);
state->ls_threads++; state->ls_threads++;
VI_UNLOCK(vp); VI_UNLOCK(vp);
} }
@ -657,8 +659,9 @@ lf_advlockasync(struct vop_advlockasync_args *ap, struct lockf **statep,
* locked. lf_purgelocks() requires that no new threads add * locked. lf_purgelocks() requires that no new threads add
* pending locks when vnode is marked by VIRF_DOOMED flag. * pending locks when vnode is marked by VIRF_DOOMED flag.
*/ */
VI_LOCK(vp);
if (VN_IS_DOOMED(vp)) { if (VN_IS_DOOMED(vp)) {
VI_LOCK(vp);
MPASS(state->ls_threads > 0);
state->ls_threads--; state->ls_threads--;
wakeup(state); wakeup(state);
VI_UNLOCK(vp); VI_UNLOCK(vp);
@ -666,7 +669,6 @@ lf_advlockasync(struct vop_advlockasync_args *ap, struct lockf **statep,
lf_free_lock(lock); lf_free_lock(lock);
return (ENOENT); return (ENOENT);
} }
VI_UNLOCK(vp);
switch (ap->a_op) { switch (ap->a_op) {
case F_SETLK: case F_SETLK:
@ -728,15 +730,11 @@ lf_advlockasync(struct vop_advlockasync_args *ap, struct lockf **statep,
sx_xunlock(&state->ls_lock); sx_xunlock(&state->ls_lock);
VI_LOCK(vp); VI_LOCK(vp);
MPASS(state->ls_threads > 0);
state->ls_threads--; state->ls_threads--;
if (LIST_EMPTY(&state->ls_active) && state->ls_threads == 0) { if (state->ls_threads != 0) {
KASSERT(LIST_EMPTY(&state->ls_pending),
("freeable state with pending locks"));
} else {
wakeup(state); wakeup(state);
} }
VI_UNLOCK(vp); VI_UNLOCK(vp);
if (error == EDOOFUS) { if (error == EDOOFUS) {
@ -790,6 +788,7 @@ lf_purgelocks(struct vnode *vp, struct lockf **statep)
VI_UNLOCK(vp); VI_UNLOCK(vp);
goto out_free; goto out_free;
} }
MPASS(state->ls_threads >= 0);
state->ls_threads++; state->ls_threads++;
VI_UNLOCK(vp); VI_UNLOCK(vp);
@ -1953,6 +1952,7 @@ lf_iteratelocks_vnode(struct vnode *vp, lf_iterator *fn, void *arg)
VI_UNLOCK(vp); VI_UNLOCK(vp);
return (0); return (0);
} }
MPASS(ls->ls_threads >= 0);
ls->ls_threads++; ls->ls_threads++;
VI_UNLOCK(vp); VI_UNLOCK(vp);
@ -1976,6 +1976,7 @@ lf_iteratelocks_vnode(struct vnode *vp, lf_iterator *fn, void *arg)
} }
sx_xunlock(&ls->ls_lock); sx_xunlock(&ls->ls_lock);
VI_LOCK(vp); VI_LOCK(vp);
MPASS(ls->ls_threads > 0);
ls->ls_threads--; ls->ls_threads--;
wakeup(ls); wakeup(ls);
VI_UNLOCK(vp); VI_UNLOCK(vp);