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: Steven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>

3 files changed, 14 insertions, 28 deletions

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 592aa5040d29..a0117d6eb145 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -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;
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 530d3f6f6ea8..402b6a2cd2c9 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -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);
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 2ada6e10d07b..e8ef0f80fb11 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -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 @@ found:
 
         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 */