Commit f3dd1649 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher Committed by Bob Peterson
Browse files

gfs2: Remove gl_spin define 



Commit e66cf161 replaced the gl_spin spinlock in struct gfs2_glock with a
gl_lockref lockref and defined gl_spin as gl_lockref.lock (the spinlock in
gl_lockref).  Remove that define to make the references to gl_lockref.lock more
obvious.

Signed-off-by: default avatarAndreas Gruenbacher <andreas.gruenbacher@gmail.com>
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
parent 491e94f7

Documentation/filesystems/gfs2-glocks.txt

+3 −3
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ This documents the basic principles of the glock state machine 
internals. Each glock (struct gfs2_glock in fs/gfs2/incore.h)

has two main (internal) locks:



 1. A spinlock (gl_spin) which protects the internal state such

 1. A spinlock (gl_lockref.lock) which protects the internal state such

    as gl_state, gl_target and the list of holders (gl_holders)

 2. A non-blocking bit lock, GLF_LOCK, which is used to prevent other

    threads from making calls to the DLM, etc. at the same time. If a
@@ -82,8 +82,8 @@ rather than via the glock. 


Locking rules for glock operations:



Operation     |  GLF_LOCK bit lock held |  gl_spin spinlock held

-----------------------------------------------------------------

Operation     |  GLF_LOCK bit lock held |  gl_lockref.lock spinlock held

-------------------------------------------------------------------------

go_xmote_th   |       Yes               |       No

go_xmote_bh   |       Yes               |       No

go_inval      |       Yes               |       No

fs/gfs2/glock.c

+42 −42
Original line number Diff line number Diff line
@@ -246,8 +246,8 @@ static inline void do_error(struct gfs2_glock *gl, const int ret) 
 */



static int do_promote(struct gfs2_glock *gl)

__releases(&gl->gl_spin)

__acquires(&gl->gl_spin)

__releases(&gl->gl_lockref.lock)

__acquires(&gl->gl_lockref.lock)

{

	const struct gfs2_glock_operations *glops = gl->gl_ops;

	struct gfs2_holder *gh, *tmp;
@@ -260,10 +260,10 @@ restart: 
		if (may_grant(gl, gh)) {

			if (gh->gh_list.prev == &gl->gl_holders &&

			    glops->go_lock) {

				spin_unlock(&gl->gl_spin);

				spin_unlock(&gl->gl_lockref.lock);

				/* FIXME: eliminate this eventually */

				ret = glops->go_lock(gh);

				spin_lock(&gl->gl_spin);

				spin_lock(&gl->gl_lockref.lock);

				if (ret) {

					if (ret == 1)

						return 2;
@@ -361,7 +361,7 @@ static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) 
	unsigned state = ret & LM_OUT_ST_MASK;

	int rv;



	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	trace_gfs2_glock_state_change(gl, state);

	state_change(gl, state);

	gh = find_first_waiter(gl);
@@ -405,7 +405,7 @@ retry: 
			pr_err("wanted %u got %u\n", gl->gl_target, state);

			GLOCK_BUG_ON(gl, 1);

		}

		spin_unlock(&gl->gl_spin);

		spin_unlock(&gl->gl_lockref.lock);

		return;

	}
@@ -414,9 +414,9 @@ retry: 
		gfs2_demote_wake(gl);

	if (state != LM_ST_UNLOCKED) {

		if (glops->go_xmote_bh) {

			spin_unlock(&gl->gl_spin);

			spin_unlock(&gl->gl_lockref.lock);

			rv = glops->go_xmote_bh(gl, gh);

			spin_lock(&gl->gl_spin);

			spin_lock(&gl->gl_lockref.lock);

			if (rv) {

				do_error(gl, rv);

				goto out;
@@ -429,7 +429,7 @@ retry: 
out:

	clear_bit(GLF_LOCK, &gl->gl_flags);

out_locked:

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);

}



/**
@@ -441,8 +441,8 @@ out_locked: 
 */



static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)

__releases(&gl->gl_spin)

__acquires(&gl->gl_spin)

__releases(&gl->gl_lockref.lock)

__acquires(&gl->gl_lockref.lock)

{

	const struct gfs2_glock_operations *glops = gl->gl_ops;

	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
@@ -464,7 +464,7 @@ __acquires(&gl->gl_spin) 
	    (gl->gl_state == LM_ST_EXCLUSIVE) ||

	    (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB)))

		clear_bit(GLF_BLOCKING, &gl->gl_flags);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);

	if (glops->go_sync)

		glops->go_sync(gl);

	if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags))
@@ -485,7 +485,7 @@ __acquires(&gl->gl_spin) 
			gfs2_glock_put(gl);

	}



	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

}



/**
@@ -513,8 +513,8 @@ static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) 
 */



static void run_queue(struct gfs2_glock *gl, const int nonblock)

__releases(&gl->gl_spin)

__acquires(&gl->gl_spin)

__releases(&gl->gl_lockref.lock)

__acquires(&gl->gl_lockref.lock)

{

	struct gfs2_holder *gh = NULL;

	int ret;
@@ -596,7 +596,7 @@ static void glock_work_func(struct work_struct *work) 
		finish_xmote(gl, gl->gl_reply);

		drop_ref = 1;

	}

	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&

	    gl->gl_state != LM_ST_UNLOCKED &&

	    gl->gl_demote_state != LM_ST_EXCLUSIVE) {
@@ -612,7 +612,7 @@ static void glock_work_func(struct work_struct *work) 
		}

	}

	run_queue(gl, 0);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);

	if (!delay)

		gfs2_glock_put(gl);

	else {
@@ -876,8 +876,8 @@ void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) 
 */



static inline void add_to_queue(struct gfs2_holder *gh)

__releases(&gl->gl_spin)

__acquires(&gl->gl_spin)

__releases(&gl->gl_lockref.lock)

__acquires(&gl->gl_lockref.lock)

{

	struct gfs2_glock *gl = gh->gh_gl;

	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
@@ -926,10 +926,10 @@ fail: 
do_cancel:

	gh = list_entry(gl->gl_holders.next, struct gfs2_holder, gh_list);

	if (!(gh->gh_flags & LM_FLAG_PRIORITY)) {

		spin_unlock(&gl->gl_spin);

		spin_unlock(&gl->gl_lockref.lock);

		if (sdp->sd_lockstruct.ls_ops->lm_cancel)

			sdp->sd_lockstruct.ls_ops->lm_cancel(gl);

		spin_lock(&gl->gl_spin);

		spin_lock(&gl->gl_lockref.lock);

	}

	return;
@@ -967,7 +967,7 @@ int gfs2_glock_nq(struct gfs2_holder *gh) 
	if (test_bit(GLF_LRU, &gl->gl_flags))

		gfs2_glock_remove_from_lru(gl);



	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	add_to_queue(gh);

	if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&

		     test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) {
@@ -977,7 +977,7 @@ int gfs2_glock_nq(struct gfs2_holder *gh) 
			gl->gl_lockref.count--;

	}

	run_queue(gl, 1);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);



	if (!(gh->gh_flags & GL_ASYNC))

		error = gfs2_glock_wait(gh);
@@ -1010,7 +1010,7 @@ void gfs2_glock_dq(struct gfs2_holder *gh) 
	unsigned delay = 0;

	int fast_path = 0;



	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	if (gh->gh_flags & GL_NOCACHE)

		handle_callback(gl, LM_ST_UNLOCKED, 0, false);
@@ -1018,9 +1018,9 @@ void gfs2_glock_dq(struct gfs2_holder *gh) 
	if (find_first_holder(gl) == NULL) {

		if (glops->go_unlock) {

			GLOCK_BUG_ON(gl, test_and_set_bit(GLF_LOCK, &gl->gl_flags));

			spin_unlock(&gl->gl_spin);

			spin_unlock(&gl->gl_lockref.lock);

			glops->go_unlock(gh);

			spin_lock(&gl->gl_spin);

			spin_lock(&gl->gl_lockref.lock);

			clear_bit(GLF_LOCK, &gl->gl_flags);

		}

		if (list_empty(&gl->gl_holders) &&
@@ -1033,7 +1033,7 @@ void gfs2_glock_dq(struct gfs2_holder *gh) 
		gfs2_glock_add_to_lru(gl);



	trace_gfs2_glock_queue(gh, 0);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);

	if (likely(fast_path))

		return;
@@ -1217,9 +1217,9 @@ void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) 
			delay = gl->gl_hold_time;

	}



	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	handle_callback(gl, state, delay, true);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);

	if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)

		gfs2_glock_put(gl);

}
@@ -1259,7 +1259,7 @@ static int gfs2_should_freeze(const struct gfs2_glock *gl) 
 * @gl: Pointer to the glock

 * @ret: The return value from the dlm

 *

 * The gl_reply field is under the gl_spin lock so that it is ok

 * The gl_reply field is under the gl_lockref.lock lock so that it is ok

 * to use a bitfield shared with other glock state fields.

 */
@@ -1267,20 +1267,20 @@ void gfs2_glock_complete(struct gfs2_glock *gl, int ret) 
{

	struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct;



	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	gl->gl_reply = ret;



	if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) {

		if (gfs2_should_freeze(gl)) {

			set_bit(GLF_FROZEN, &gl->gl_flags);

			spin_unlock(&gl->gl_spin);

			spin_unlock(&gl->gl_lockref.lock);

			return;

		}

	}



	gl->gl_lockref.count++;

	set_bit(GLF_REPLY_PENDING, &gl->gl_flags);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);



	if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)

		gfs2_glock_put(gl);
@@ -1326,14 +1326,14 @@ __acquires(&lru_lock) 
	while(!list_empty(list)) {

		gl = list_entry(list->next, struct gfs2_glock, gl_lru);

		list_del_init(&gl->gl_lru);

		if (!spin_trylock(&gl->gl_spin)) {

		if (!spin_trylock(&gl->gl_lockref.lock)) {

add_back_to_lru:

			list_add(&gl->gl_lru, &lru_list);

			atomic_inc(&lru_count);

			continue;

		}

		if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {

			spin_unlock(&gl->gl_spin);

			spin_unlock(&gl->gl_lockref.lock);

			goto add_back_to_lru;

		}

		clear_bit(GLF_LRU, &gl->gl_flags);
@@ -1343,7 +1343,7 @@ add_back_to_lru: 
		WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));

		if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)

			gl->gl_lockref.count--;

		spin_unlock(&gl->gl_spin);

		spin_unlock(&gl->gl_lockref.lock);

		cond_resched_lock(&lru_lock);

	}

}
@@ -1461,10 +1461,10 @@ static void clear_glock(struct gfs2_glock *gl) 
{

	gfs2_glock_remove_from_lru(gl);



	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	if (gl->gl_state != LM_ST_UNLOCKED)

		handle_callback(gl, LM_ST_UNLOCKED, 0, false);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);

	if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)

		gfs2_glock_put(gl);

}
@@ -1482,9 +1482,9 @@ void gfs2_glock_thaw(struct gfs2_sbd *sdp) 


static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl)

{

	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	gfs2_dump_glock(seq, gl);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);

}



static void dump_glock_func(struct gfs2_glock *gl)
@@ -1518,10 +1518,10 @@ void gfs2_glock_finish_truncate(struct gfs2_inode *ip) 
	ret = gfs2_truncatei_resume(ip);

	gfs2_assert_withdraw(gl->gl_name.ln_sbd, ret == 0);



	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	clear_bit(GLF_LOCK, &gl->gl_flags);

	run_queue(gl, 1);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);

}



static const char *state2str(unsigned state)

fs/gfs2/glock.h

+2 −2
Original line number Diff line number Diff line
@@ -141,7 +141,7 @@ static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock * 
	struct pid *pid;



	/* Look in glock's list of holders for one with current task as owner */

	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	pid = task_pid(current);

	list_for_each_entry(gh, &gl->gl_holders, gh_list) {

		if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
@@ -151,7 +151,7 @@ static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock * 
	}

	gh = NULL;

out:

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);



	return gh;

}

fs/gfs2/glops.c

+5 −5
Original line number Diff line number Diff line
@@ -146,11 +146,11 @@ static void rgrp_go_sync(struct gfs2_glock *gl) 
	struct gfs2_rgrpd *rgd;

	int error;



	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	rgd = gl->gl_object;

	if (rgd)

		gfs2_rgrp_brelse(rgd);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);



	if (!test_and_clear_bit(GLF_DIRTY, &gl->gl_flags))

		return;
@@ -162,11 +162,11 @@ static void rgrp_go_sync(struct gfs2_glock *gl) 
	mapping_set_error(mapping, error);

	gfs2_ail_empty_gl(gl);



	spin_lock(&gl->gl_spin);

	spin_lock(&gl->gl_lockref.lock);

	rgd = gl->gl_object;

	if (rgd)

		gfs2_free_clones(rgd);

	spin_unlock(&gl->gl_spin);

	spin_unlock(&gl->gl_lockref.lock);

}



/**
@@ -542,7 +542,7 @@ static int freeze_go_demote_ok(const struct gfs2_glock *gl) 
 * iopen_go_callback - schedule the dcache entry for the inode to be deleted

 * @gl: the glock

 *

 * gl_spin lock is held while calling this

 * gl_lockref.lock lock is held while calling this

 */

static void iopen_go_callback(struct gfs2_glock *gl, bool remote)

{

fs/gfs2/incore.h

+1 −2
Original line number Diff line number Diff line
@@ -334,9 +334,8 @@ struct gfs2_glock { 
	struct lm_lockname gl_name;



	struct lockref gl_lockref;

#define gl_spin gl_lockref.lock



	/* State fields protected by gl_spin */

	/* State fields protected by gl_lockref.lock */

	unsigned int gl_state:2,	/* Current state */

		     gl_target:2,	/* Target state */

		     gl_demote_state:2,	/* State requested by remote node */

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