GFS2: Move quota bitmap operations under their own lock
Gradually, the global qd_lock is being used for less and less.
After this patch it will only be used for the per super block
list whose purpose is to allow syncing of changes back to the
master quota file from the local quota changes file. Fixing
up that process to make it more efficient will be the subject
of a later patch, however this patch removes another barrier
to doing that.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 4b9aa5b..8c64e26 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -734,6 +734,7 @@
unsigned int sd_quota_slots;
unsigned long *sd_quota_bitmap;
+ spinlock_t sd_bitmap_lock;
u64 sd_quota_sync_gen;
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 27648e8..06a66c9 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -99,6 +99,7 @@
init_waitqueue_head(&sdp->sd_quota_wait);
INIT_LIST_HEAD(&sdp->sd_trunc_list);
spin_lock_init(&sdp->sd_trunc_lock);
+ spin_lock_init(&sdp->sd_bitmap_lock);
mapping = &sdp->sd_aspace;
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 79be67a..02a2740 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -76,6 +76,7 @@
#define GFS2_QD_HASH_MASK (GFS2_QD_HASH_SIZE - 1)
/* Lock order: qd_lock -> bucket lock -> qd->lockref.lock -> lru lock */
+/* -> sd_bitmap_lock */
static DEFINE_SPINLOCK(qd_lock);
struct list_lru gfs2_qd_lru;
@@ -319,7 +320,7 @@
unsigned int bit;
int error = 0;
- spin_lock(&qd_lock);
+ spin_lock(&sdp->sd_bitmap_lock);
if (qd->qd_slot_count != 0)
goto out;
@@ -331,7 +332,7 @@
out:
qd->qd_slot_count++;
}
- spin_unlock(&qd_lock);
+ spin_unlock(&sdp->sd_bitmap_lock);
return error;
}
@@ -340,23 +341,23 @@
{
struct gfs2_sbd *sdp = qd->qd_sbd;
- spin_lock(&qd_lock);
+ spin_lock(&sdp->sd_bitmap_lock);
gfs2_assert(sdp, qd->qd_slot_count);
qd->qd_slot_count++;
- spin_unlock(&qd_lock);
+ spin_unlock(&sdp->sd_bitmap_lock);
}
static void slot_put(struct gfs2_quota_data *qd)
{
struct gfs2_sbd *sdp = qd->qd_sbd;
- spin_lock(&qd_lock);
+ spin_lock(&sdp->sd_bitmap_lock);
gfs2_assert(sdp, qd->qd_slot_count);
if (!--qd->qd_slot_count) {
BUG_ON(!test_and_clear_bit(qd->qd_slot, sdp->sd_quota_bitmap));
qd->qd_slot = -1;
}
- spin_unlock(&qd_lock);
+ spin_unlock(&sdp->sd_bitmap_lock);
}
static int bh_get(struct gfs2_quota_data *qd)
@@ -434,8 +435,7 @@
list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
set_bit(QDF_LOCKED, &qd->qd_flags);
qd->qd_change_sync = qd->qd_change;
- gfs2_assert_warn(sdp, qd->qd_slot_count);
- qd->qd_slot_count++;
+ slot_hold(qd);
return 1;
}