xfs: convert dquot cache lru to list_lru

Convert the XFS dquot lru to use the list_lru construct and convert the
shrinker to being node aware.

[glommer@openvz.org: edited for conflicts + warning fixes]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 142 insertions, 135 deletions

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 956da2e1c7af..0fa98753bf67 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -51,8 +51,9 @@
  */
 STATIC int      xfs_qm_init_quotainos(xfs_mount_t *);
 STATIC int      xfs_qm_init_quotainfo(xfs_mount_t *);
-STATIC int      xfs_qm_shake(struct shrinker *, struct shrink_control *);
 
+
+STATIC void     xfs_qm_dqfree_one(struct xfs_dquot *dqp);
 /*
  * We use the batch lookup interface to iterate over the dquots as it
  * currently is the only interface into the radix tree code that allows
@@ -203,12 +204,9 @@ xfs_qm_dqpurge(
          * We move dquots to the freelist as soon as their reference count
          * hits zero, so it really should be on the freelist here.
          */
-        mutex_lock(&qi->qi_lru_lock);
         ASSERT(!list_empty(&dqp->q_lru));
-        list_del_init(&dqp->q_lru);
-        qi->qi_lru_count--;
+        list_lru_del(&qi->qi_lru, &dqp->q_lru);
         XFS_STATS_DEC(xs_qm_dquot_unused);
-        mutex_unlock(&qi->qi_lru_lock);
 
         xfs_qm_dqdestroy(dqp);
 
@@ -680,6 +678,141 @@ xfs_qm_calc_dquots_per_chunk(
         return ndquots;
 }
 
+struct xfs_qm_isolate {
+        struct list_head        buffers;
+        struct list_head        dispose;
+};
+
+static enum lru_status
+xfs_qm_dquot_isolate(
+        struct list_head        *item,
+        spinlock_t              *lru_lock,
+        void                    *arg)
+{
+        struct xfs_dquot        *dqp = container_of(item,
+                                                struct xfs_dquot, q_lru);
+        struct xfs_qm_isolate   *isol = arg;
+
+        if (!xfs_dqlock_nowait(dqp))
+                goto out_miss_busy;
+
+        /*
+         * This dquot has acquired a reference in the meantime remove it from
+         * the freelist and try again.
+         */
+        if (dqp->q_nrefs) {
+                xfs_dqunlock(dqp);
+                XFS_STATS_INC(xs_qm_dqwants);
+
+                trace_xfs_dqreclaim_want(dqp);
+                list_del_init(&dqp->q_lru);
+                XFS_STATS_DEC(xs_qm_dquot_unused);
+                return 0;
+        }
+
+        /*
+         * If the dquot is dirty, flush it. If it's already being flushed, just
+         * skip it so there is time for the IO to complete before we try to
+         * reclaim it again on the next LRU pass.
+         */
+        if (!xfs_dqflock_nowait(dqp)) {
+                xfs_dqunlock(dqp);
+                goto out_miss_busy;
+        }
+
+        if (XFS_DQ_IS_DIRTY(dqp)) {
+                struct xfs_buf  *bp = NULL;
+                int             error;
+
+                trace_xfs_dqreclaim_dirty(dqp);
+
+                /* we have to drop the LRU lock to flush the dquot */
+                spin_unlock(lru_lock);
+
+                error = xfs_qm_dqflush(dqp, &bp);
+                if (error) {
+                        xfs_warn(dqp->q_mount, "%s: dquot %p flush failed",
+                                 __func__, dqp);
+                        goto out_unlock_dirty;
+                }
+
+                xfs_buf_delwri_queue(bp, &isol->buffers);
+                xfs_buf_relse(bp);
+                goto out_unlock_dirty;
+        }
+        xfs_dqfunlock(dqp);
+
+        /*
+         * Prevent lookups now that we are past the point of no return.
+         */
+        dqp->dq_flags |= XFS_DQ_FREEING;
+        xfs_dqunlock(dqp);
+
+        ASSERT(dqp->q_nrefs == 0);
+        list_move_tail(&dqp->q_lru, &isol->dispose);
+        XFS_STATS_DEC(xs_qm_dquot_unused);
+        trace_xfs_dqreclaim_done(dqp);
+        XFS_STATS_INC(xs_qm_dqreclaims);
+        return 0;
+
+out_miss_busy:
+        trace_xfs_dqreclaim_busy(dqp);
+        XFS_STATS_INC(xs_qm_dqreclaim_misses);
+        return 2;
+
+out_unlock_dirty:
+        trace_xfs_dqreclaim_busy(dqp);
+        XFS_STATS_INC(xs_qm_dqreclaim_misses);
+        return 3;
+}
+
+static long
+xfs_qm_shrink_scan(
+        struct shrinker         *shrink,
+        struct shrink_control   *sc)
+{
+        struct xfs_quotainfo    *qi = container_of(shrink,
+                                        struct xfs_quotainfo, qi_shrinker);
+        struct xfs_qm_isolate   isol;
+        long                    freed;
+        int                     error;
+        unsigned long           nr_to_scan = sc->nr_to_scan;
+
+        if ((sc->gfp_mask & (__GFP_FS|__GFP_WAIT)) != (__GFP_FS|__GFP_WAIT))
+                return 0;
+
+        INIT_LIST_HEAD(&isol.buffers);
+        INIT_LIST_HEAD(&isol.dispose);
+
+        freed = list_lru_walk_node(&qi->qi_lru, sc->nid, xfs_qm_dquot_isolate, &isol,
+                                        &nr_to_scan);
+
+        error = xfs_buf_delwri_submit(&isol.buffers);
+        if (error)
+                xfs_warn(NULL, "%s: dquot reclaim failed", __func__);
+
+        while (!list_empty(&isol.dispose)) {
+                struct xfs_dquot        *dqp;
+
+                dqp = list_first_entry(&isol.dispose, struct xfs_dquot, q_lru);
+                list_del_init(&dqp->q_lru);
+                xfs_qm_dqfree_one(dqp);
+        }
+
+        return freed;
+}
+
+static long
+xfs_qm_shrink_count(
+        struct shrinker         *shrink,
+        struct shrink_control   *sc)
+{
+        struct xfs_quotainfo    *qi = container_of(shrink,
+                                        struct xfs_quotainfo, qi_shrinker);
+
+        return list_lru_count_node(&qi->qi_lru, sc->nid);
+}
+
 /*
  * This initializes all the quota information that's kept in the
  * mount structure
@@ -711,9 +844,7 @@ xfs_qm_init_quotainfo(
         INIT_RADIX_TREE(&qinf->qi_pquota_tree, GFP_NOFS);
         mutex_init(&qinf->qi_tree_lock);
 
-        INIT_LIST_HEAD(&qinf->qi_lru_list);
-        qinf->qi_lru_count = 0;
-        mutex_init(&qinf->qi_lru_lock);
+        list_lru_init(&qinf->qi_lru);
 
         /* mutex used to serialize quotaoffs */
         mutex_init(&qinf->qi_quotaofflock);
@@ -779,8 +910,10 @@ xfs_qm_init_quotainfo(
                 qinf->qi_rtbwarnlimit = XFS_QM_RTBWARNLIMIT;
         }
 
-        qinf->qi_shrinker.shrink = xfs_qm_shake;
+        qinf->qi_shrinker.count_objects = xfs_qm_shrink_count;
+        qinf->qi_shrinker.scan_objects = xfs_qm_shrink_scan;
         qinf->qi_shrinker.seeks = DEFAULT_SEEKS;
+        qinf->qi_shrinker.flags = SHRINKER_NUMA_AWARE;
         register_shrinker(&qinf->qi_shrinker);
         return 0;
 }
@@ -1599,132 +1732,6 @@ xfs_qm_dqfree_one(
         xfs_qm_dqdestroy(dqp);
 }
 
-STATIC void
-xfs_qm_dqreclaim_one(
-        struct xfs_dquot        *dqp,
-        struct list_head        *buffer_list,
-        struct list_head        *dispose_list)
-{
-        struct xfs_mount        *mp = dqp->q_mount;
-        struct xfs_quotainfo    *qi = mp->m_quotainfo;
-        int                     error;
-
-        if (!xfs_dqlock_nowait(dqp))
-                goto out_move_tail;
-
-        /*
-         * This dquot has acquired a reference in the meantime remove it from
-         * the freelist and try again.
-         */
-        if (dqp->q_nrefs) {
-                xfs_dqunlock(dqp);
-
-                trace_xfs_dqreclaim_want(dqp);
-                XFS_STATS_INC(xs_qm_dqwants);
-
-                list_del_init(&dqp->q_lru);
-                qi->qi_lru_count--;
-                XFS_STATS_DEC(xs_qm_dquot_unused);
-                return;
-        }
-
-        /*
-         * Try to grab the flush lock. If this dquot is in the process of
-         * getting flushed to disk, we don't want to reclaim it.
-         */
-        if (!xfs_dqflock_nowait(dqp))
-                goto out_unlock_move_tail;
-
-        if (XFS_DQ_IS_DIRTY(dqp)) {
-                struct xfs_buf  *bp = NULL;
-
-                trace_xfs_dqreclaim_dirty(dqp);
-
-                error = xfs_qm_dqflush(dqp, &bp);
-                if (error) {
-                        xfs_warn(mp, "%s: dquot %p flush failed",
-                                 __func__, dqp);
-                        goto out_unlock_move_tail;
-                }
-
-                xfs_buf_delwri_queue(bp, buffer_list);
-                xfs_buf_relse(bp);
-                /*
-                 * Give the dquot another try on the freelist, as the
-                 * flushing will take some time.
-                 */
-                goto out_unlock_move_tail;
-        }
-        xfs_dqfunlock(dqp);
-
-        /*
-         * Prevent lookups now that we are past the point of no return.
-         */
-        dqp->dq_flags |= XFS_DQ_FREEING;
-        xfs_dqunlock(dqp);
-
-        ASSERT(dqp->q_nrefs == 0);
-        list_move_tail(&dqp->q_lru, dispose_list);
-        qi->qi_lru_count--;
-        XFS_STATS_DEC(xs_qm_dquot_unused);
-
-        trace_xfs_dqreclaim_done(dqp);
-        XFS_STATS_INC(xs_qm_dqreclaims);
-        return;
-
-        /*
-         * Move the dquot to the tail of the list so that we don't spin on it.
-         */
-out_unlock_move_tail:
-        xfs_dqunlock(dqp);
-out_move_tail:
-        list_move_tail(&dqp->q_lru, &qi->qi_lru_list);
-        trace_xfs_dqreclaim_busy(dqp);
-        XFS_STATS_INC(xs_qm_dqreclaim_misses);
-}
-
-STATIC int
-xfs_qm_shake(
-        struct shrinker         *shrink,
-        struct shrink_control   *sc)
-{
-        struct xfs_quotainfo    *qi =
-                container_of(shrink, struct xfs_quotainfo, qi_shrinker);
-        int                     nr_to_scan = sc->nr_to_scan;
-        LIST_HEAD               (buffer_list);
-        LIST_HEAD               (dispose_list);
-        struct xfs_dquot        *dqp;
-        int                     error;
-
-        if ((sc->gfp_mask & (__GFP_FS|__GFP_WAIT)) != (__GFP_FS|__GFP_WAIT))
-                return 0;
-        if (!nr_to_scan)
-                goto out;
-
-        mutex_lock(&qi->qi_lru_lock);
-        while (!list_empty(&qi->qi_lru_list)) {
-                if (nr_to_scan-- <= 0)
-                        break;
-                dqp = list_first_entry(&qi->qi_lru_list, struct xfs_dquot,
-                                       q_lru);
-                xfs_qm_dqreclaim_one(dqp, &buffer_list, &dispose_list);
-        }
-        mutex_unlock(&qi->qi_lru_lock);
-
-        error = xfs_buf_delwri_submit(&buffer_list);
-        if (error)
-                xfs_warn(NULL, "%s: dquot reclaim failed", __func__);
-
-        while (!list_empty(&dispose_list)) {
-                dqp = list_first_entry(&dispose_list, struct xfs_dquot, q_lru);
-                list_del_init(&dqp->q_lru);
-                xfs_qm_dqfree_one(dqp);
-        }
-
-out:
-        return vfs_pressure_ratio(qi->qi_lru_count);
-}
-
 /*
  * Start a transaction and write the incore superblock changes to
  * disk. flags parameter indicates which fields have changed.