GFS2: change gfs2_quota_scan into a shrinker
Deallocation of gfs2_quota_data objects now happens on-demand through a
shrinker instead of routinely deallocating through the quotad daemon.
Signed-off-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index b08d096..2ada6e1 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -80,6 +80,53 @@
u32 qc_id;
};
+static LIST_HEAD(qd_lru_list);
+static atomic_t qd_lru_count = ATOMIC_INIT(0);
+static spinlock_t qd_lru_lock = SPIN_LOCK_UNLOCKED;
+
+int gfs2_shrink_qd_memory(int nr, gfp_t gfp_mask)
+{
+ struct gfs2_quota_data *qd;
+ struct gfs2_sbd *sdp;
+
+ if (nr == 0)
+ goto out;
+
+ if (!(gfp_mask & __GFP_FS))
+ return -1;
+
+ spin_lock(&qd_lru_lock);
+ while (nr && !list_empty(&qd_lru_list)) {
+ qd = list_entry(qd_lru_list.next,
+ struct gfs2_quota_data, qd_reclaim);
+ sdp = qd->qd_gl->gl_sbd;
+
+ /* 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 */
+ list_del_init(&qd->qd_reclaim);
+ atomic_dec(&qd_lru_count);
+ spin_unlock(&qd_lru_lock);
+ kmem_cache_free(gfs2_quotad_cachep, qd);
+ spin_lock(&qd_lru_lock);
+ nr--;
+ }
+ spin_unlock(&qd_lru_lock);
+
+out:
+ return (atomic_read(&qd_lru_count) * sysctl_vfs_cache_pressure) / 100;
+}
+
static u64 qd2offset(struct gfs2_quota_data *qd)
{
u64 offset;
@@ -100,11 +147,12 @@
if (!qd)
return -ENOMEM;
- qd->qd_count = 1;
+ atomic_set(&qd->qd_count, 1);
qd->qd_id = id;
if (user)
set_bit(QDF_USER, &qd->qd_flags);
qd->qd_slot = -1;
+ INIT_LIST_HEAD(&qd->qd_reclaim);
error = gfs2_glock_get(sdp, 2 * (u64)id + !user,
&gfs2_quota_glops, CREATE, &qd->qd_gl);
@@ -135,11 +183,17 @@
for (;;) {
found = 0;
- spin_lock(&sdp->sd_quota_spin);
+ spin_lock(&qd_lru_lock);
list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
if (qd->qd_id == id &&
!test_bit(QDF_USER, &qd->qd_flags) == !user) {
- qd->qd_count++;
+ if (!atomic_read(&qd->qd_count) &&
+ !list_empty(&qd->qd_reclaim)) {
+ /* Remove it from reclaim list */
+ list_del_init(&qd->qd_reclaim);
+ atomic_dec(&qd_lru_count);
+ }
+ atomic_inc(&qd->qd_count);
found = 1;
break;
}
@@ -155,7 +209,7 @@
new_qd = NULL;
}
- spin_unlock(&sdp->sd_quota_spin);
+ spin_unlock(&qd_lru_lock);
if (qd || !create) {
if (new_qd) {
@@ -175,21 +229,18 @@
static void qd_hold(struct gfs2_quota_data *qd)
{
struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
-
- spin_lock(&sdp->sd_quota_spin);
- gfs2_assert(sdp, qd->qd_count);
- qd->qd_count++;
- spin_unlock(&sdp->sd_quota_spin);
+ gfs2_assert(sdp, atomic_read(&qd->qd_count));
+ atomic_inc(&qd->qd_count);
}
static void qd_put(struct gfs2_quota_data *qd)
{
- struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
- spin_lock(&sdp->sd_quota_spin);
- gfs2_assert(sdp, qd->qd_count);
- if (!--qd->qd_count)
- qd->qd_last_touched = jiffies;
- spin_unlock(&sdp->sd_quota_spin);
+ if (atomic_dec_and_lock(&qd->qd_count, &qd_lru_lock)) {
+ /* Add to the reclaim list */
+ list_add_tail(&qd->qd_reclaim, &qd_lru_list);
+ atomic_inc(&qd_lru_count);
+ spin_unlock(&qd_lru_lock);
+ }
}
static int slot_get(struct gfs2_quota_data *qd)
@@ -330,6 +381,7 @@
if (sdp->sd_vfs->s_flags & MS_RDONLY)
return 0;
+ spin_lock(&qd_lru_lock);
spin_lock(&sdp->sd_quota_spin);
list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
@@ -341,8 +393,8 @@
list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
set_bit(QDF_LOCKED, &qd->qd_flags);
- gfs2_assert_warn(sdp, qd->qd_count);
- qd->qd_count++;
+ gfs2_assert_warn(sdp, atomic_read(&qd->qd_count));
+ atomic_inc(&qd->qd_count);
qd->qd_change_sync = qd->qd_change;
gfs2_assert_warn(sdp, qd->qd_slot_count);
qd->qd_slot_count++;
@@ -355,6 +407,7 @@
qd = NULL;
spin_unlock(&sdp->sd_quota_spin);
+ spin_unlock(&qd_lru_lock);
if (qd) {
gfs2_assert_warn(sdp, qd->qd_change_sync);
@@ -379,24 +432,27 @@
if (sdp->sd_vfs->s_flags & MS_RDONLY)
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;
}
list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
set_bit(QDF_LOCKED, &qd->qd_flags);
- gfs2_assert_warn(sdp, qd->qd_count);
- qd->qd_count++;
+ gfs2_assert_warn(sdp, atomic_read(&qd->qd_count));
+ atomic_inc(&qd->qd_count);
qd->qd_change_sync = qd->qd_change;
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);
if (bh_get(qd)) {
@@ -802,8 +858,8 @@
loff_t pos;
gfs2_glock_dq_uninit(q_gh);
error = gfs2_glock_nq_init(qd->qd_gl,
- LM_ST_EXCLUSIVE, GL_NOCACHE,
- q_gh);
+ LM_ST_EXCLUSIVE, GL_NOCACHE,
+ q_gh);
if (error)
return error;
@@ -820,7 +876,6 @@
gfs2_glock_dq_uninit(&i_gh);
-
gfs2_quota_in(&q, buf);
qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lvb;
qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
@@ -1171,13 +1226,14 @@
qd->qd_change = qc.qc_change;
qd->qd_slot = slot;
qd->qd_slot_count = 1;
- qd->qd_last_touched = jiffies;
+ 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(&sdp->sd_quota_spin);
+ spin_unlock(&qd_lru_lock);
found++;
}
@@ -1197,61 +1253,39 @@
return error;
}
-static void gfs2_quota_scan(struct gfs2_sbd *sdp)
-{
- struct gfs2_quota_data *qd, *safe;
- LIST_HEAD(dead);
-
- spin_lock(&sdp->sd_quota_spin);
- list_for_each_entry_safe(qd, safe, &sdp->sd_quota_list, qd_list) {
- if (!qd->qd_count &&
- time_after_eq(jiffies, qd->qd_last_touched +
- gfs2_tune_get(sdp, gt_quota_cache_secs) * HZ)) {
- list_move(&qd->qd_list, &dead);
- gfs2_assert_warn(sdp,
- atomic_read(&sdp->sd_quota_count) > 0);
- atomic_dec(&sdp->sd_quota_count);
- }
- }
- spin_unlock(&sdp->sd_quota_spin);
-
- while (!list_empty(&dead)) {
- qd = list_entry(dead.next, struct gfs2_quota_data, qd_list);
- list_del(&qd->qd_list);
-
- 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);
- kmem_cache_free(gfs2_quotad_cachep, qd);
- }
-}
-
void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
{
struct list_head *head = &sdp->sd_quota_list;
struct gfs2_quota_data *qd;
unsigned int x;
- spin_lock(&sdp->sd_quota_spin);
+ spin_lock(&qd_lru_lock);
while (!list_empty(head)) {
qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
- if (qd->qd_count > 1 ||
- (qd->qd_count && !test_bit(QDF_CHANGE, &qd->qd_flags))) {
- list_move(&qd->qd_list, head);
+ 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(&sdp->sd_quota_spin);
+ spin_lock(&qd_lru_lock);
continue;
}
-
- list_del(&qd->qd_list);
- atomic_dec(&sdp->sd_quota_count);
spin_unlock(&sdp->sd_quota_spin);
- if (!qd->qd_count) {
+ list_del(&qd->qd_list);
+ /* Also remove if this qd exists in the reclaim list */
+ if (!list_empty(&qd->qd_reclaim)) {
+ list_del_init(&qd->qd_reclaim);
+ atomic_dec(&qd_lru_count);
+ }
+ atomic_dec(&sdp->sd_quota_count);
+ spin_unlock(&qd_lru_lock);
+
+ if (!atomic_read(&qd->qd_count)) {
gfs2_assert_warn(sdp, !qd->qd_change);
gfs2_assert_warn(sdp, !qd->qd_slot_count);
} else
@@ -1261,9 +1295,9 @@
gfs2_lvb_unhold(qd->qd_gl);
kmem_cache_free(gfs2_quotad_cachep, qd);
- spin_lock(&sdp->sd_quota_spin);
+ spin_lock(&qd_lru_lock);
}
- spin_unlock(&sdp->sd_quota_spin);
+ spin_unlock(&qd_lru_lock);
gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
@@ -1341,9 +1375,6 @@
quotad_check_timeo(sdp, "sync", gfs2_quota_sync, t,
"ad_timeo, &tune->gt_quota_quantum);
- /* FIXME: This should be turned into a shrinker */
- gfs2_quota_scan(sdp);
-
/* Check for & recover partially truncated inodes */
quotad_check_trunc_list(sdp);