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Commit 22077f57 authored by Steven Whitehouse's avatar Steven Whitehouse Committed by Steven Whitehouse
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GFS2: Remove "double" locking in quota 



We only really need a single spin lock for the quota data, so
lets just use the lru lock for now.

Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>
parent 0a7ab79c

fs/gfs2/incore.h

+0 −1
Original line number Diff line number Diff line
@@ -540,7 +540,6 @@ struct gfs2_sbd { 


	struct list_head sd_quota_list;

	atomic_t sd_quota_count;

	spinlock_t sd_quota_spin;

	struct mutex sd_quota_mutex;

	wait_queue_head_t sd_quota_wait;

	struct list_head sd_trunc_list;

fs/gfs2/ops_fstype.c

+0 −1
Original line number Diff line number Diff line
@@ -98,7 +98,6 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb) 
	mutex_init(&sdp->sd_jindex_mutex);



	INIT_LIST_HEAD(&sdp->sd_quota_list);

	spin_lock_init(&sdp->sd_quota_spin);

	mutex_init(&sdp->sd_quota_mutex);

	init_waitqueue_head(&sdp->sd_quota_wait);

	INIT_LIST_HEAD(&sdp->sd_trunc_list);

fs/gfs2/quota.c

+14 −26
Original line number Diff line number Diff line
@@ -104,13 +104,11 @@ int gfs2_shrink_qd_memory(int nr, gfp_t gfp_mask) 
		/* Free from the filesystem-specific list */

		list_del(&qd->qd_list);



		spin_lock(&sdp->sd_quota_spin);

		gfs2_assert_warn(sdp, !qd->qd_change);

		gfs2_assert_warn(sdp, !qd->qd_slot_count);

		gfs2_assert_warn(sdp, !qd->qd_bh_count);



		gfs2_lvb_unhold(qd->qd_gl);

		spin_unlock(&sdp->sd_quota_spin);

		atomic_dec(&sdp->sd_quota_count);



		/* Delete it from the common reclaim list */
@@ -249,10 +247,10 @@ static int slot_get(struct gfs2_quota_data *qd) 
	unsigned int c, o = 0, b;

	unsigned char byte = 0;



	spin_lock(&sdp->sd_quota_spin);

	spin_lock(&qd_lru_lock);



	if (qd->qd_slot_count++) {

		spin_unlock(&sdp->sd_quota_spin);

		spin_unlock(&qd_lru_lock);

		return 0;

	}
@@ -276,13 +274,13 @@ static int slot_get(struct gfs2_quota_data *qd) 


	sdp->sd_quota_bitmap[c][o] |= 1 << b;



	spin_unlock(&sdp->sd_quota_spin);

	spin_unlock(&qd_lru_lock);



	return 0;



fail:

	qd->qd_slot_count--;

	spin_unlock(&sdp->sd_quota_spin);

	spin_unlock(&qd_lru_lock);

	return -ENOSPC;

}
@@ -290,23 +288,23 @@ static void slot_hold(struct gfs2_quota_data *qd) 
{

	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;



	spin_lock(&sdp->sd_quota_spin);

	spin_lock(&qd_lru_lock);

	gfs2_assert(sdp, qd->qd_slot_count);

	qd->qd_slot_count++;

	spin_unlock(&sdp->sd_quota_spin);

	spin_unlock(&qd_lru_lock);

}



static void slot_put(struct gfs2_quota_data *qd)

{

	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;



	spin_lock(&sdp->sd_quota_spin);

	spin_lock(&qd_lru_lock);

	gfs2_assert(sdp, qd->qd_slot_count);

	if (!--qd->qd_slot_count) {

		gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);

		qd->qd_slot = -1;

	}

	spin_unlock(&sdp->sd_quota_spin);

	spin_unlock(&qd_lru_lock);

}



static int bh_get(struct gfs2_quota_data *qd)
@@ -382,7 +380,6 @@ static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp) 
		return 0;



	spin_lock(&qd_lru_lock);

	spin_lock(&sdp->sd_quota_spin);



	list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {

		if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
@@ -406,7 +403,6 @@ static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp) 
	if (!found)

		qd = NULL;



	spin_unlock(&sdp->sd_quota_spin);

	spin_unlock(&qd_lru_lock);



	if (qd) {
@@ -433,11 +429,9 @@ static int qd_trylock(struct gfs2_quota_data *qd) 
		return 0;



	spin_lock(&qd_lru_lock);

	spin_lock(&sdp->sd_quota_spin);



	if (test_bit(QDF_LOCKED, &qd->qd_flags) ||

	    !test_bit(QDF_CHANGE, &qd->qd_flags)) {

		spin_unlock(&sdp->sd_quota_spin);

		spin_unlock(&qd_lru_lock);

		return 0;

	}
@@ -451,7 +445,6 @@ static int qd_trylock(struct gfs2_quota_data *qd) 
	gfs2_assert_warn(sdp, qd->qd_slot_count);

	qd->qd_slot_count++;



	spin_unlock(&sdp->sd_quota_spin);

	spin_unlock(&qd_lru_lock);



	gfs2_assert_warn(sdp, qd->qd_change_sync);
@@ -612,9 +605,9 @@ static void do_qc(struct gfs2_quota_data *qd, s64 change) 
	x = be64_to_cpu(qc->qc_change) + change;

	qc->qc_change = cpu_to_be64(x);



	spin_lock(&sdp->sd_quota_spin);

	spin_lock(&qd_lru_lock);

	qd->qd_change = x;

	spin_unlock(&sdp->sd_quota_spin);

	spin_unlock(&qd_lru_lock);



	if (!x) {

		gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
@@ -945,9 +938,9 @@ static int need_sync(struct gfs2_quota_data *qd) 
	if (!qd->qd_qb.qb_limit)

		return 0;



	spin_lock(&sdp->sd_quota_spin);

	spin_lock(&qd_lru_lock);

	value = qd->qd_change;

	spin_unlock(&sdp->sd_quota_spin);

	spin_unlock(&qd_lru_lock);



	spin_lock(&gt->gt_spin);

	num = gt->gt_quota_scale_num;
@@ -1040,9 +1033,9 @@ int gfs2_quota_check(struct gfs2_inode *ip, u32 uid, u32 gid) 
			continue;



		value = (s64)be64_to_cpu(qd->qd_qb.qb_value);

		spin_lock(&sdp->sd_quota_spin);

		spin_lock(&qd_lru_lock);

		value += qd->qd_change;

		spin_unlock(&sdp->sd_quota_spin);

		spin_unlock(&qd_lru_lock);



		if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {

			print_message(qd, "exceeded");
@@ -1228,9 +1221,7 @@ int gfs2_quota_init(struct gfs2_sbd *sdp) 
			qd->qd_slot_count = 1;



			spin_lock(&qd_lru_lock);

			spin_lock(&sdp->sd_quota_spin);

			gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);

			spin_unlock(&sdp->sd_quota_spin);

			list_add(&qd->qd_list, &sdp->sd_quota_list);

			atomic_inc(&sdp->sd_quota_count);

			spin_unlock(&qd_lru_lock);
@@ -1263,18 +1254,15 @@ void gfs2_quota_cleanup(struct gfs2_sbd *sdp) 
	while (!list_empty(head)) {

		qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);



		spin_lock(&sdp->sd_quota_spin);

		if (atomic_read(&qd->qd_count) > 1 ||

		    (atomic_read(&qd->qd_count) &&

		     !test_bit(QDF_CHANGE, &qd->qd_flags))) {

			spin_unlock(&sdp->sd_quota_spin);

			list_move(&qd->qd_list, head);

			spin_unlock(&qd_lru_lock);

			schedule();

			spin_lock(&qd_lru_lock);

			continue;

		}

		spin_unlock(&sdp->sd_quota_spin);



		list_del(&qd->qd_list);

		/* Also remove if this qd exists in the reclaim list */