/**
* demote_incompat_holders - demote incompatible demoteable holders
* @gl: the glock we want to promote
- * @new_gh: the new holder to be promoted
+ * @current_gh: the newly promoted holder
+ *
+ * We're passing the newly promoted holder in @current_gh, but actually, any of
+ * the strong holders would do.
*/
static void demote_incompat_holders(struct gfs2_glock *gl,
- struct gfs2_holder *new_gh)
+ struct gfs2_holder *current_gh)
{
struct gfs2_holder *gh, *tmp;
*/
if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
return;
+ if (gh == current_gh)
+ continue;
if (test_bit(HIF_MAY_DEMOTE, &gh->gh_iflags) &&
- !may_grant(gl, new_gh, gh)) {
+ !may_grant(gl, current_gh, gh)) {
/*
* We should not recurse into do_promote because
* __gfs2_glock_dq only calls handle_callback,
* gfs2_instantiate - Call the glops instantiate function
* @gh: The glock holder
*
- * Returns: 0 if instantiate was successful, 2 if type specific operation is
- * underway, or error.
+ * Returns: 0 if instantiate was successful, or error.
*/
int gfs2_instantiate(struct gfs2_holder *gh)
{
again:
if (!test_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags))
- return 0;
+ goto done;
/*
* Since we unlock the lockref lock, we set a flag to indicate
goto again;
}
- ret = glops->go_instantiate(gh);
+ ret = glops->go_instantiate(gl);
if (!ret)
clear_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags);
clear_and_wake_up_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags);
- return ret;
+ if (ret)
+ return ret;
+
+ done:
+ if (glops->go_held)
+ return glops->go_held(gh);
+ return 0;
}
/**
* do_promote - promote as many requests as possible on the current queue
* @gl: The glock
*
- * Returns: 1 if there is a blocked holder at the head of the list, or 2
- * if a type specific operation is underway.
+ * Returns: 1 if there is a blocked holder at the head of the list
*/
static int do_promote(struct gfs2_glock *gl)
- __releases(&gl->gl_lockref.lock)
- __acquires(&gl->gl_lockref.lock)
{
- struct gfs2_holder *gh, *tmp, *first_gh;
+ struct gfs2_holder *gh, *current_gh;
bool incompat_holders_demoted = false;
- bool lock_released;
- int ret;
- restart:
- first_gh = find_first_strong_holder(gl);
- list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) {
- lock_released = false;
+ current_gh = find_first_strong_holder(gl);
+ list_for_each_entry(gh, &gl->gl_holders, gh_list) {
if (test_bit(HIF_HOLDER, &gh->gh_iflags))
continue;
- if (!may_grant(gl, first_gh, gh)) {
+ if (!may_grant(gl, current_gh, gh)) {
/*
- * If we get here, it means we may not grant this holder for
- * some reason. If this holder is the head of the list, it
- * means we have a blocked holder at the head, so return 1.
+ * If we get here, it means we may not grant this
+ * holder for some reason. If this holder is at the
+ * head of the list, it means we have a blocked holder
+ * at the head, so return 1.
*/
if (list_is_first(&gh->gh_list, &gl->gl_holders))
return 1;
do_error(gl, 0);
break;
}
- if (!incompat_holders_demoted) {
- demote_incompat_holders(gl, first_gh);
- incompat_holders_demoted = true;
- first_gh = gh;
- }
- if (test_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags) &&
- !(gh->gh_flags & GL_SKIP) && gl->gl_ops->go_instantiate) {
- lock_released = true;
- spin_unlock(&gl->gl_lockref.lock);
- ret = gfs2_instantiate(gh);
- spin_lock(&gl->gl_lockref.lock);
- if (ret) {
- if (ret == 1)
- return 2;
- gh->gh_error = ret;
- list_del_init(&gh->gh_list);
- trace_gfs2_glock_queue(gh, 0);
- gfs2_holder_wake(gh);
- goto restart;
- }
- }
set_bit(HIF_HOLDER, &gh->gh_iflags);
trace_gfs2_promote(gh);
gfs2_holder_wake(gh);
- /*
- * If we released the gl_lockref.lock the holders list may have
- * changed. For that reason, we start again at the start of
- * the holders queue.
- */
- if (lock_released)
- goto restart;
+ if (!incompat_holders_demoted) {
+ current_gh = gh;
+ demote_incompat_holders(gl, current_gh);
+ incompat_holders_demoted = true;
+ }
}
return 0;
}
const struct gfs2_glock_operations *glops = gl->gl_ops;
struct gfs2_holder *gh;
unsigned state = ret & LM_OUT_ST_MASK;
- int rv;
spin_lock(&gl->gl_lockref.lock);
trace_gfs2_glock_state_change(gl, state);
gfs2_demote_wake(gl);
if (state != LM_ST_UNLOCKED) {
if (glops->go_xmote_bh) {
+ int rv;
+
spin_unlock(&gl->gl_lockref.lock);
rv = glops->go_xmote_bh(gl);
spin_lock(&gl->gl_lockref.lock);
goto out;
}
}
- rv = do_promote(gl);
- if (rv == 2)
- goto out_locked;
+ do_promote(gl);
}
out:
clear_bit(GLF_LOCK, &gl->gl_flags);
- out_locked:
spin_unlock(&gl->gl_lockref.lock);
}
__acquires(&gl->gl_lockref.lock)
{
struct gfs2_holder *gh = NULL;
- int ret;
if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
return;
} else {
if (test_bit(GLF_DEMOTE, &gl->gl_flags))
gfs2_demote_wake(gl);
- ret = do_promote(gl);
- if (ret == 0)
+ if (do_promote(gl) == 0)
goto out_unlock;
- if (ret == 2)
- goto out;
gh = find_first_waiter(gl);
gl->gl_target = gh->gh_state;
if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)))
do_error(gl, 0); /* Fail queued try locks */
}
do_xmote(gl, gh, gl->gl_target);
- out:
return;
out_sched:
}
}
+ /**
+ * gfs2_glock_holder_ready - holder is ready and its error code can be collected
+ * @gh: the glock holder
+ *
+ * Called when a glock holder no longer needs to be waited for because it is
+ * now either held (HIF_HOLDER set; gh_error == 0), or acquiring the lock has
+ * failed (gh_error != 0).
+ */
+
+ int gfs2_glock_holder_ready(struct gfs2_holder *gh)
+ {
+ if (gh->gh_error || (gh->gh_flags & GL_SKIP))
+ return gh->gh_error;
+ gh->gh_error = gfs2_instantiate(gh);
+ if (gh->gh_error)
+ gfs2_glock_dq(gh);
+ return gh->gh_error;
+ }
+
/**
* gfs2_glock_wait - wait on a glock acquisition
* @gh: the glock holder
might_sleep();
wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE);
gfs2_glock_update_hold_time(gh->gh_gl, start_time);
- return gh->gh_error;
+ return gfs2_glock_holder_ready(gh);
}
static int glocks_pending(unsigned int num_gh, struct gfs2_holder *ghs)
struct gfs2_sbd *sdp = ghs[0].gh_gl->gl_name.ln_sbd;
int i, ret = 0, timeout = 0;
unsigned long start_time = jiffies;
- bool keep_waiting;
might_sleep();
/*
for (i = 0; i < num_gh; i++)
timeout += ghs[i].gh_gl->gl_hold_time << 1;
- wait_for_dlm:
if (!wait_event_timeout(sdp->sd_async_glock_wait,
- !glocks_pending(num_gh, ghs), timeout))
+ !glocks_pending(num_gh, ghs), timeout)) {
ret = -ESTALE; /* request timed out. */
+ goto out;
+ }
- /*
- * If dlm granted all our requests, we need to adjust the glock
- * minimum hold time values according to how long we waited.
- *
- * If our request timed out, we need to repeatedly release any held
- * glocks we acquired thus far to allow dlm to acquire the remaining
- * glocks without deadlocking. We cannot currently cancel outstanding
- * glock acquisitions.
- *
- * The HIF_WAIT bit tells us which requests still need a response from
- * dlm.
- *
- * If dlm sent us any errors, we return the first error we find.
- */
- keep_waiting = false;
for (i = 0; i < num_gh; i++) {
- /* Skip holders we have already dequeued below. */
- if (!gfs2_holder_queued(&ghs[i]))
- continue;
- /* Skip holders with a pending DLM response. */
- if (test_bit(HIF_WAIT, &ghs[i].gh_iflags)) {
- keep_waiting = true;
- continue;
- }
+ struct gfs2_holder *gh = &ghs[i];
+ int ret2;
- if (test_bit(HIF_HOLDER, &ghs[i].gh_iflags)) {
- if (ret == -ESTALE)
- gfs2_glock_dq(&ghs[i]);
- else
- gfs2_glock_update_hold_time(ghs[i].gh_gl,
- start_time);
+ if (test_bit(HIF_HOLDER, &gh->gh_iflags)) {
+ gfs2_glock_update_hold_time(gh->gh_gl,
+ start_time);
}
+ ret2 = gfs2_glock_holder_ready(gh);
if (!ret)
- ret = ghs[i].gh_error;
+ ret = ret2;
}
- if (keep_waiting)
- goto wait_for_dlm;
+ out:
+ if (ret) {
+ for (i = 0; i < num_gh; i++) {
+ struct gfs2_holder *gh = &ghs[i];
- /*
- * At this point, we've either acquired all locks or released them all.
- */
+ gfs2_glock_dq(gh);
+ }
+ }
return ret;
}
if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) {
if (test_bit(GLF_LOCK, &gl->gl_flags)) {
- struct gfs2_holder *first_gh;
+ struct gfs2_holder *current_gh;
- first_gh = find_first_strong_holder(gl);
- try_futile = !may_grant(gl, first_gh, gh);
+ current_gh = find_first_strong_holder(gl);
+ try_futile = !may_grant(gl, current_gh, gh);
}
if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
goto fail;
}
/**
- * nq_m_sync - synchonously acquire more than one glock in deadlock free order
+ * nq_m_sync - synchronously acquire more than one glock in deadlock free order
* @num_gh: the number of structures
* @ghs: an array of struct gfs2_holder structures
* @p: placeholder for the holder structure to pass back
sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL);
for (x = 0; x < num_gh; x++) {
- p[x]->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
-
error = gfs2_glock_nq(p[x]);
if (error) {
while (x--)
* @num_gh: the number of structures
* @ghs: an array of struct gfs2_holder structures
*
- *
* Returns: 0 on success (all glocks acquired),
* errno on failure (no glocks acquired)
*/
case 0:
return 0;
case 1:
- ghs->gh_flags &= ~(LM_FLAG_TRY | GL_ASYNC);
return gfs2_glock_nq(ghs);
default:
if (num_gh <= 4)
glock_hash_walk(dump_glock_func, sdp);
}
- void gfs2_glock_finish_truncate(struct gfs2_inode *ip)
- {
- struct gfs2_glock *gl = ip->i_gl;
- int ret;
-
- ret = gfs2_truncatei_resume(ip);
- gfs2_glock_assert_withdraw(gl, ret == 0);
-
- spin_lock(&gl->gl_lockref.lock);
- clear_bit(GLF_LOCK, &gl->gl_flags);
- run_queue(gl, 1);
- spin_unlock(&gl->gl_lockref.lock);
- }
-
static const char *state2str(unsigned state)
{
switch(state) {
return -ENOMEM;
}
- ret = register_shrinker(&glock_shrinker);
+ ret = register_shrinker(&glock_shrinker, "gfs2-glock");
if (ret) {
destroy_workqueue(gfs2_delete_workqueue);
destroy_workqueue(glock_workqueue);
projects / linux.git / commitdiff