From 2147dbfd059eb7fefcfd5934f74f25f0693d4a1f Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Mon, 4 Nov 2013 10:15:08 +0000 Subject: [PATCH] GFS2: Use generic list_lru for quota By using the generic list_lru code, we can now separate the per sb quota list locking from the lru locking. The lru lock is made into the inner-most lock. As a result of this new lock order, we may occasionally see items on the per-sb quota list which are "dead" so that the two places where we traverse that list are updated to take account of that. As a result of this patch, the gfs2 quota shrinker is now NUMA zone aware, and we are also laying the foundations for further improvments in due course. Signed-off-by: Steven Whitehouse Signed-off-by: Abhijith Das Tested-by: Abhijith Das Cc: Dave Chinner --- fs/gfs2/incore.h | 5 +- fs/gfs2/main.c | 19 ++++---- fs/gfs2/quota.c | 118 +++++++++++++++++++++++++++-------------------- fs/gfs2/quota.h | 9 ++-- 4 files changed, 85 insertions(+), 66 deletions(-) diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h index 9d778044cc6e..ba1ea67f4eeb 100644 --- a/fs/gfs2/incore.h +++ b/fs/gfs2/incore.h @@ -420,11 +420,10 @@ enum { struct gfs2_quota_data { struct list_head qd_list; - struct list_head qd_reclaim; - + struct kqid qd_id; struct lockref qd_lockref; + struct list_head qd_lru; - struct kqid qd_id; unsigned long qd_flags; /* QDF_... */ s64 qd_change; diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c index 351586e24e30..0650db2541ef 100644 --- a/fs/gfs2/main.c +++ b/fs/gfs2/main.c @@ -31,12 +31,6 @@ struct workqueue_struct *gfs2_control_wq; -static struct shrinker qd_shrinker = { - .count_objects = gfs2_qd_shrink_count, - .scan_objects = gfs2_qd_shrink_scan, - .seeks = DEFAULT_SEEKS, -}; - static void gfs2_init_inode_once(void *foo) { struct gfs2_inode *ip = foo; @@ -87,6 +81,10 @@ static int __init init_gfs2_fs(void) if (error) return error; + error = list_lru_init(&gfs2_qd_lru); + if (error) + goto fail_lru; + error = gfs2_glock_init(); if (error) goto fail; @@ -139,7 +137,7 @@ static int __init init_gfs2_fs(void) if (!gfs2_rsrv_cachep) goto fail; - register_shrinker(&qd_shrinker); + register_shrinker(&gfs2_qd_shrinker); error = register_filesystem(&gfs2_fs_type); if (error) @@ -179,7 +177,9 @@ fail_wq: fail_unregister: unregister_filesystem(&gfs2_fs_type); fail: - unregister_shrinker(&qd_shrinker); + list_lru_destroy(&gfs2_qd_lru); +fail_lru: + unregister_shrinker(&gfs2_qd_shrinker); gfs2_glock_exit(); if (gfs2_rsrv_cachep) @@ -214,13 +214,14 @@ fail: static void __exit exit_gfs2_fs(void) { - unregister_shrinker(&qd_shrinker); + unregister_shrinker(&gfs2_qd_shrinker); gfs2_glock_exit(); gfs2_unregister_debugfs(); unregister_filesystem(&gfs2_fs_type); unregister_filesystem(&gfs2meta_fs_type); destroy_workqueue(gfs_recovery_wq); destroy_workqueue(gfs2_control_wq); + list_lru_destroy(&gfs2_qd_lru); rcu_barrier(); diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c index 466516ac5e57..453b50eaddec 100644 --- a/fs/gfs2/quota.c +++ b/fs/gfs2/quota.c @@ -51,6 +51,7 @@ #include #include #include +#include #include "gfs2.h" #include "incore.h" @@ -72,29 +73,25 @@ struct gfs2_quota_change_host { struct kqid qc_id; }; -static LIST_HEAD(qd_lru_list); -static atomic_t qd_lru_count = ATOMIC_INIT(0); +/* Lock order: qd_lock -> qd->lockref.lock -> lru lock */ static DEFINE_SPINLOCK(qd_lock); +struct list_lru gfs2_qd_lru; -unsigned long gfs2_qd_shrink_scan(struct shrinker *shrink, - struct shrink_control *sc) +static void gfs2_qd_dispose(struct list_head *list) { struct gfs2_quota_data *qd; struct gfs2_sbd *sdp; - int nr_to_scan = sc->nr_to_scan; - long freed = 0; - if (!(sc->gfp_mask & __GFP_FS)) - return SHRINK_STOP; - - spin_lock(&qd_lock); - while (nr_to_scan && !list_empty(&qd_lru_list)) { - qd = list_entry(qd_lru_list.next, - struct gfs2_quota_data, qd_reclaim); + while (!list_empty(list)) { + qd = list_entry(list->next, struct gfs2_quota_data, qd_lru); sdp = qd->qd_gl->gl_sbd; + list_del(&qd->qd_lru); + /* Free from the filesystem-specific list */ + spin_lock(&qd_lock); list_del(&qd->qd_list); + spin_unlock(&qd_lock); gfs2_assert_warn(sdp, !qd->qd_change); gfs2_assert_warn(sdp, !qd->qd_slot_count); @@ -104,24 +101,59 @@ unsigned long gfs2_qd_shrink_scan(struct shrinker *shrink, 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_lock); kmem_cache_free(gfs2_quotad_cachep, qd); - spin_lock(&qd_lock); - nr_to_scan--; - freed++; } - spin_unlock(&qd_lock); +} + + +static enum lru_status gfs2_qd_isolate(struct list_head *item, spinlock_t *lock, void *arg) +{ + struct list_head *dispose = arg; + struct gfs2_quota_data *qd = list_entry(item, struct gfs2_quota_data, qd_lru); + + if (!spin_trylock(&qd->qd_lockref.lock)) + return LRU_SKIP; + + if (qd->qd_lockref.count == 0) { + lockref_mark_dead(&qd->qd_lockref); + list_move(&qd->qd_lru, dispose); + } + + spin_unlock(&qd->qd_lockref.lock); + return LRU_REMOVED; +} + +static unsigned long gfs2_qd_shrink_scan(struct shrinker *shrink, + struct shrink_control *sc) +{ + LIST_HEAD(dispose); + unsigned long freed; + + if (!(sc->gfp_mask & __GFP_FS)) + return SHRINK_STOP; + + freed = list_lru_walk_node(&gfs2_qd_lru, sc->nid, gfs2_qd_isolate, + &dispose, &sc->nr_to_scan); + + gfs2_qd_dispose(&dispose); + return freed; } -unsigned long gfs2_qd_shrink_count(struct shrinker *shrink, - struct shrink_control *sc) +static unsigned long gfs2_qd_shrink_count(struct shrinker *shrink, + struct shrink_control *sc) { - return vfs_pressure_ratio(atomic_read(&qd_lru_count)); + return vfs_pressure_ratio(list_lru_count_node(&gfs2_qd_lru, sc->nid)); } +struct shrinker gfs2_qd_shrinker = { + .count_objects = gfs2_qd_shrink_count, + .scan_objects = gfs2_qd_shrink_scan, + .seeks = DEFAULT_SEEKS, + .flags = SHRINKER_NUMA_AWARE, +}; + + static u64 qd2index(struct gfs2_quota_data *qd) { struct kqid qid = qd->qd_id; @@ -153,7 +185,7 @@ static int qd_alloc(struct gfs2_sbd *sdp, struct kqid qid, spin_lock_init(&qd->qd_lockref.lock); qd->qd_id = qid; qd->qd_slot = -1; - INIT_LIST_HEAD(&qd->qd_reclaim); + INIT_LIST_HEAD(&qd->qd_lru); error = gfs2_glock_get(sdp, qd2index(qd), &gfs2_quota_glops, CREATE, &qd->qd_gl); @@ -181,13 +213,9 @@ static int qd_get(struct gfs2_sbd *sdp, struct kqid qid, found = 0; spin_lock(&qd_lock); list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) { - if (qid_eq(qd->qd_id, qid)) { - lockref_get(&qd->qd_lockref); - if (!list_empty(&qd->qd_reclaim)) { - /* Remove it from reclaim list */ - list_del_init(&qd->qd_reclaim); - atomic_dec(&qd_lru_count); - } + if (qid_eq(qd->qd_id, qid) && + lockref_get_not_dead(&qd->qd_lockref)) { + list_lru_del(&gfs2_qd_lru, &qd->qd_lru); found = 1; break; } @@ -229,18 +257,13 @@ static void qd_hold(struct gfs2_quota_data *qd) static void qd_put(struct gfs2_quota_data *qd) { - spin_lock(&qd_lock); - - if (!lockref_put_or_lock(&qd->qd_lockref)) { + if (lockref_put_or_lock(&qd->qd_lockref)) + return; - /* Add to the reclaim list */ - list_add_tail(&qd->qd_reclaim, &qd_lru_list); - atomic_inc(&qd_lru_count); + qd->qd_lockref.count = 0; + list_lru_add(&gfs2_qd_lru, &qd->qd_lru); + spin_unlock(&qd->qd_lockref.lock); - spin_unlock(&qd->qd_lockref.lock); - } - - spin_unlock(&qd_lock); } static int slot_get(struct gfs2_quota_data *qd) @@ -398,11 +421,11 @@ static int qd_check_sync(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd, (sync_gen && (qd->qd_sync_gen >= *sync_gen))) return 0; - list_move_tail(&qd->qd_list, &sdp->sd_quota_list); + if (!lockref_get_not_dead(&qd->qd_lockref)) + return 0; + list_move_tail(&qd->qd_list, &sdp->sd_quota_list); set_bit(QDF_LOCKED, &qd->qd_flags); - gfs2_assert_warn(sdp, !__lockref_is_dead(&qd->qd_lockref)); - lockref_get(&qd->qd_lockref); qd->qd_change_sync = qd->qd_change; gfs2_assert_warn(sdp, qd->qd_slot_count); qd->qd_slot_count++; @@ -1329,10 +1352,7 @@ void gfs2_quota_cleanup(struct gfs2_sbd *sdp) 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); - } + list_lru_del(&gfs2_qd_lru, &qd->qd_lru); atomic_dec(&sdp->sd_quota_count); spin_unlock(&qd_lock); @@ -1487,7 +1507,7 @@ static int gfs2_quota_get_xstate(struct super_block *sb, } fqs->qs_uquota.qfs_nextents = 1; /* unsupported */ fqs->qs_gquota = fqs->qs_uquota; /* its the same inode in both cases */ - fqs->qs_incoredqs = atomic_read(&qd_lru_count); + fqs->qs_incoredqs = list_lru_count(&gfs2_qd_lru); return 0; } diff --git a/fs/gfs2/quota.h b/fs/gfs2/quota.h index 0f64d9deb1b0..96e4f34a03b0 100644 --- a/fs/gfs2/quota.h +++ b/fs/gfs2/quota.h @@ -10,9 +10,10 @@ #ifndef __QUOTA_DOT_H__ #define __QUOTA_DOT_H__ +#include + struct gfs2_inode; struct gfs2_sbd; -struct shrink_control; #define NO_UID_QUOTA_CHANGE INVALID_UID #define NO_GID_QUOTA_CHANGE INVALID_GID @@ -53,10 +54,8 @@ static inline int gfs2_quota_lock_check(struct gfs2_inode *ip) return ret; } -extern unsigned long gfs2_qd_shrink_count(struct shrinker *shrink, - struct shrink_control *sc); -extern unsigned long gfs2_qd_shrink_scan(struct shrinker *shrink, - struct shrink_control *sc); extern const struct quotactl_ops gfs2_quotactl_ops; +extern struct shrinker gfs2_qd_shrinker; +extern struct list_lru gfs2_qd_lru; #endif /* __QUOTA_DOT_H__ */ -- 2.20.1