1 files changed, 137 insertions, 142 deletions

diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c
index a427c638d909..dfcbd98d1599 100644
--- a/fs/xfs/linux-2.6/xfs_sync.c
+++ b/fs/xfs/linux-2.6/xfs_sync.c
@@ -24,25 +24,14 @@
 #include "xfs_trans.h"
 #include "xfs_sb.h"
 #include "xfs_ag.h"
-#include "xfs_dir2.h"
-#include "xfs_dmapi.h"
 #include "xfs_mount.h"
 #include "xfs_bmap_btree.h"
-#include "xfs_alloc_btree.h"
-#include "xfs_ialloc_btree.h"
-#include "xfs_btree.h"
-#include "xfs_dir2_sf.h"
-#include "xfs_attr_sf.h"
 #include "xfs_inode.h"
 #include "xfs_dinode.h"
 #include "xfs_error.h"
-#include "xfs_mru_cache.h"
 #include "xfs_filestream.h"
 #include "xfs_vnodeops.h"
-#include "xfs_utils.h"
-#include "xfs_buf_item.h"
 #include "xfs_inode_item.h"
-#include "xfs_rw.h"
 #include "xfs_quota.h"
 #include "xfs_trace.h"
 
@@ -144,6 +133,41 @@ restart:
         return last_error;
 }
 
+/*
+ * Select the next per-ag structure to iterate during the walk. The reclaim
+ * walk is optimised only to walk AGs with reclaimable inodes in them.
+ */
+static struct xfs_perag *
+xfs_inode_ag_iter_next_pag(
+        struct xfs_mount        *mp,
+        xfs_agnumber_t          *first,
+        int                     tag)
+{
+        struct xfs_perag        *pag = NULL;
+
+        if (tag == XFS_ICI_RECLAIM_TAG) {
+                int found;
+                int ref;
+
+                spin_lock(&mp->m_perag_lock);
+                found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
+                                (void **)&pag, *first, 1, tag);
+                if (found <= 0) {
+                        spin_unlock(&mp->m_perag_lock);
+                        return NULL;
+                }
+                *first = pag->pag_agno + 1;
+                /* open coded pag reference increment */
+                ref = atomic_inc_return(&pag->pag_ref);
+                spin_unlock(&mp->m_perag_lock);
+                trace_xfs_perag_get_reclaim(mp, pag->pag_agno, ref, _RET_IP_);
+        } else {
+                pag = xfs_perag_get(mp, *first);
+                (*first)++;
+        }
+        return pag;
+}
+
 int
 xfs_inode_ag_iterator(
         struct xfs_mount        *mp,
@@ -154,20 +178,15 @@ xfs_inode_ag_iterator(
         int                     exclusive,
         int                     *nr_to_scan)
 {
+        struct xfs_perag        *pag;
         int                     error = 0;
         int                     last_error = 0;
         xfs_agnumber_t          ag;
         int                     nr;
 
         nr = nr_to_scan ? *nr_to_scan : INT_MAX;
-        for (ag = 0; ag < mp->m_sb.sb_agcount; ag++) {
-                struct xfs_perag        *pag;
-
-                pag = xfs_perag_get(mp, ag);
-                if (!pag->pag_ici_init) {
-                        xfs_perag_put(pag);
-                        continue;
-                }
+        ag = 0;
+        while ((pag = xfs_inode_ag_iter_next_pag(mp, &ag, tag))) {
                 error = xfs_inode_ag_walk(mp, pag, execute, flags, tag,
                                                 exclusive, &nr);
                 xfs_perag_put(pag);
@@ -289,7 +308,7 @@ xfs_sync_inode_attr(
 /*
  * Write out pagecache data for the whole filesystem.
  */
-int
+STATIC int
 xfs_sync_data(
         struct xfs_mount        *mp,
         int                     flags)
@@ -310,7 +329,7 @@ xfs_sync_data(
 /*
  * Write out inode metadata (attributes) for the whole filesystem.
  */
-int
+STATIC int
 xfs_sync_attr(
         struct xfs_mount        *mp,
         int                     flags)
@@ -343,8 +362,7 @@ xfs_commit_dummy_trans(
 
         xfs_ilock(ip, XFS_ILOCK_EXCL);
 
-        xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
-        xfs_trans_ihold(tp, ip);
+        xfs_trans_ijoin(tp, ip);
         xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
         error = xfs_trans_commit(tp, 0);
         xfs_iunlock(ip, XFS_ILOCK_EXCL);
@@ -356,68 +374,23 @@ xfs_commit_dummy_trans(
 
 STATIC int
 xfs_sync_fsdata(
-        struct xfs_mount        *mp,
-        int                     flags)
+        struct xfs_mount        *mp)
 {
         struct xfs_buf          *bp;
-        struct xfs_buf_log_item *bip;
-        int                     error = 0;
 
         /*
-         * If this is xfssyncd() then only sync the superblock if we can
-         * lock it without sleeping and it is not pinned.
+         * If the buffer is pinned then push on the log so we won't get stuck
+         * waiting in the write for someone, maybe ourselves, to flush the log.
+         *
+         * Even though we just pushed the log above, we did not have the
+         * superblock buffer locked at that point so it can become pinned in
+         * between there and here.
          */
-        if (flags & SYNC_TRYLOCK) {
-                ASSERT(!(flags & SYNC_WAIT));
-
-                bp = xfs_getsb(mp, XBF_TRYLOCK);
-                if (!bp)
-                        goto out;
-
-                bip = XFS_BUF_FSPRIVATE(bp, struct xfs_buf_log_item *);
-                if (!bip || !xfs_buf_item_dirty(bip) || XFS_BUF_ISPINNED(bp))
-                        goto out_brelse;
-        } else {
-                bp = xfs_getsb(mp, 0);
-
-                /*
-                 * If the buffer is pinned then push on the log so we won't
-                 * get stuck waiting in the write for someone, maybe
-                 * ourselves, to flush the log.
-                 *
-                 * Even though we just pushed the log above, we did not have
-                 * the superblock buffer locked at that point so it can
-                 * become pinned in between there and here.
-                 */
-                if (XFS_BUF_ISPINNED(bp))
-                        xfs_log_force(mp, 0);
-        }
-
-
-        if (flags & SYNC_WAIT)
-                XFS_BUF_UNASYNC(bp);
-        else
-                XFS_BUF_ASYNC(bp);
-
-        error = xfs_bwrite(mp, bp);
-        if (error)
-                return error;
-
-        /*
-         * If this is a data integrity sync make sure all pending buffers
-         * are flushed out for the log coverage check below.
-         */
-        if (flags & SYNC_WAIT)
-                xfs_flush_buftarg(mp->m_ddev_targp, 1);
-
-        if (xfs_log_need_covered(mp))
-                error = xfs_commit_dummy_trans(mp, flags);
-        return error;
+        bp = xfs_getsb(mp, 0);
+        if (XFS_BUF_ISPINNED(bp))
+                xfs_log_force(mp, 0);
 
- out_brelse:
-        xfs_buf_relse(bp);
- out:
-        return error;
+        return xfs_bwrite(mp, bp);
 }
 
 /*
@@ -441,7 +414,7 @@ int
 xfs_quiesce_data(
         struct xfs_mount        *mp)
 {
-        int error;
+        int                     error, error2 = 0;
 
         /* push non-blocking */
         xfs_sync_data(mp, 0);
@@ -452,13 +425,20 @@ xfs_quiesce_data(
         xfs_qm_sync(mp, SYNC_WAIT);
 
         /* write superblock and hoover up shutdown errors */
-        error = xfs_sync_fsdata(mp, SYNC_WAIT);
+        error = xfs_sync_fsdata(mp);
+
+        /* make sure all delwri buffers are written out */
+        xfs_flush_buftarg(mp->m_ddev_targp, 1);
+
+        /* mark the log as covered if needed */
+        if (xfs_log_need_covered(mp))
+                error2 = xfs_commit_dummy_trans(mp, SYNC_WAIT);
 
         /* flush data-only devices */
         if (mp->m_rtdev_targp)
                 XFS_bflush(mp->m_rtdev_targp);
 
-        return error;
+        return error ? error : error2;
 }
 
 STATIC void
@@ -581,9 +561,9 @@ xfs_flush_inodes(
 }
 
 /*
- * Every sync period we need to unpin all items, reclaim inodes, sync
- * quota and write out the superblock. We might need to cover the log
- * to indicate it is idle.
+ * Every sync period we need to unpin all items, reclaim inodes and sync
+ * disk quotas.  We might need to cover the log to indicate that the
+ * filesystem is idle.
  */
 STATIC void
 xfs_sync_worker(
@@ -597,7 +577,8 @@ xfs_sync_worker(
                 xfs_reclaim_inodes(mp, 0);
                 /* dgc: errors ignored here */
                 error = xfs_qm_sync(mp, SYNC_TRYLOCK);
-                error = xfs_sync_fsdata(mp, SYNC_TRYLOCK);
+                if (xfs_log_need_covered(mp))
+                        error = xfs_commit_dummy_trans(mp, 0);
         }
         mp->m_sync_seq++;
         wake_up(&mp->m_wait_single_sync_task);
@@ -660,7 +641,7 @@ xfs_syncd_init(
         mp->m_sync_work.w_syncer = xfs_sync_worker;
         mp->m_sync_work.w_mount = mp;
         mp->m_sync_work.w_completion = NULL;
-        mp->m_sync_task = kthread_run(xfssyncd, mp, "xfssyncd");
+        mp->m_sync_task = kthread_run(xfssyncd, mp, "xfssyncd/%s", mp->m_fsname);
         if (IS_ERR(mp->m_sync_task))
                 return -PTR_ERR(mp->m_sync_task);
         return 0;
@@ -681,6 +662,17 @@ __xfs_inode_set_reclaim_tag(
         radix_tree_tag_set(&pag->pag_ici_root,
                            XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino),
                            XFS_ICI_RECLAIM_TAG);
+
+        if (!pag->pag_ici_reclaimable) {
+                /* propagate the reclaim tag up into the perag radix tree */
+                spin_lock(&ip->i_mount->m_perag_lock);
+                radix_tree_tag_set(&ip->i_mount->m_perag_tree,
+                                XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
+                                XFS_ICI_RECLAIM_TAG);
+                spin_unlock(&ip->i_mount->m_perag_lock);
+                trace_xfs_perag_set_reclaim(ip->i_mount, pag->pag_agno,
+                                                        -1, _RET_IP_);
+        }
         pag->pag_ici_reclaimable++;
 }
 
@@ -715,6 +707,16 @@ __xfs_inode_clear_reclaim_tag(
         radix_tree_tag_clear(&pag->pag_ici_root,
                         XFS_INO_TO_AGINO(mp, ip->i_ino), XFS_ICI_RECLAIM_TAG);
         pag->pag_ici_reclaimable--;
+        if (!pag->pag_ici_reclaimable) {
+                /* clear the reclaim tag from the perag radix tree */
+                spin_lock(&ip->i_mount->m_perag_lock);
+                radix_tree_tag_clear(&ip->i_mount->m_perag_tree,
+                                XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
+                                XFS_ICI_RECLAIM_TAG);
+                spin_unlock(&ip->i_mount->m_perag_lock);
+                trace_xfs_perag_clear_reclaim(ip->i_mount, pag->pag_agno,
+                                                        -1, _RET_IP_);
+        }
 }
 
 /*
@@ -853,7 +855,36 @@ out:
 reclaim:
         xfs_ifunlock(ip);
         xfs_iunlock(ip, XFS_ILOCK_EXCL);
-        xfs_ireclaim(ip);
+
+        XFS_STATS_INC(xs_ig_reclaims);
+        /*
+         * Remove the inode from the per-AG radix tree.
+         *
+         * Because radix_tree_delete won't complain even if the item was never
+         * added to the tree assert that it's been there before to catch
+         * problems with the inode life time early on.
+         */
+        write_lock(&pag->pag_ici_lock);
+        if (!radix_tree_delete(&pag->pag_ici_root,
+                                XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino)))
+                ASSERT(0);
+        write_unlock(&pag->pag_ici_lock);
+
+        /*
+         * Here we do an (almost) spurious inode lock in order to coordinate
+         * with inode cache radix tree lookups.  This is because the lookup
+         * can reference the inodes in the cache without taking references.
+         *
+         * We make that OK here by ensuring that we wait until the inode is
+         * unlocked after the lookup before we go ahead and free it.  We get
+         * both the ilock and the iolock because the code may need to drop the
+         * ilock one but will still hold the iolock.
+         */
+        xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+        xfs_qm_dqdetach(ip);
+        xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+
+        xfs_inode_free(ip);
         return error;
 
 }
@@ -869,88 +900,52 @@ xfs_reclaim_inodes(
 
 /*
  * Shrinker infrastructure.
- *
- * This is all far more complex than it needs to be. It adds a global list of
- * mounts because the shrinkers can only call a global context. We need to make
- * the shrinkers pass a context to avoid the need for global state.
  */
-static LIST_HEAD(xfs_mount_list);
-static struct rw_semaphore xfs_mount_list_lock;
-
 static int
 xfs_reclaim_inode_shrink(
+        struct shrinker *shrink,
         int             nr_to_scan,
         gfp_t           gfp_mask)
 {
         struct xfs_mount *mp;
         struct xfs_perag *pag;
         xfs_agnumber_t  ag;
-        int             reclaimable = 0;
+        int             reclaimable;
 
+        mp = container_of(shrink, struct xfs_mount, m_inode_shrink);
         if (nr_to_scan) {
                 if (!(gfp_mask & __GFP_FS))
                         return -1;
 
-                down_read(&xfs_mount_list_lock);
-                list_for_each_entry(mp, &xfs_mount_list, m_mplist) {
-                        xfs_inode_ag_iterator(mp, xfs_reclaim_inode, 0,
+                xfs_inode_ag_iterator(mp, xfs_reclaim_inode, 0,
                                         XFS_ICI_RECLAIM_TAG, 1, &nr_to_scan);
-                        if (nr_to_scan <= 0)
-                                break;
-                }
-                up_read(&xfs_mount_list_lock);
-        }
-
-        down_read(&xfs_mount_list_lock);
-        list_for_each_entry(mp, &xfs_mount_list, m_mplist) {
-                for (ag = 0; ag < mp->m_sb.sb_agcount; ag++) {
+                /* if we don't exhaust the scan, don't bother coming back */
+                if (nr_to_scan > 0)
+                        return -1;
+       }
 
-                        pag = xfs_perag_get(mp, ag);
-                        if (!pag->pag_ici_init) {
-                                xfs_perag_put(pag);
-                                continue;
-                        }
-                        reclaimable += pag->pag_ici_reclaimable;
-                        xfs_perag_put(pag);
-                }
+        reclaimable = 0;
+        ag = 0;
+        while ((pag = xfs_inode_ag_iter_next_pag(mp, &ag,
+                                        XFS_ICI_RECLAIM_TAG))) {
+                reclaimable += pag->pag_ici_reclaimable;
+                xfs_perag_put(pag);
         }
-        up_read(&xfs_mount_list_lock);
         return reclaimable;
 }
 
-static struct shrinker xfs_inode_shrinker = {
-        .shrink = xfs_reclaim_inode_shrink,
-        .seeks = DEFAULT_SEEKS,
-};
-
-void __init
-xfs_inode_shrinker_init(void)
-{
-        init_rwsem(&xfs_mount_list_lock);
-        register_shrinker(&xfs_inode_shrinker);
-}
-
-void
-xfs_inode_shrinker_destroy(void)
-{
-        ASSERT(list_empty(&xfs_mount_list));
-        unregister_shrinker(&xfs_inode_shrinker);
-}
-
 void
 xfs_inode_shrinker_register(
         struct xfs_mount        *mp)
 {
-        down_write(&xfs_mount_list_lock);
-        list_add_tail(&mp->m_mplist, &xfs_mount_list);
-        up_write(&xfs_mount_list_lock);
+        mp->m_inode_shrink.shrink = xfs_reclaim_inode_shrink;
+        mp->m_inode_shrink.seeks = DEFAULT_SEEKS;
+        register_shrinker(&mp->m_inode_shrink);
 }
 
 void
 xfs_inode_shrinker_unregister(
         struct xfs_mount        *mp)
 {
-        down_write(&xfs_mount_list_lock);
-        list_del(&mp->m_mplist);
-        up_write(&xfs_mount_list_lock);
+        unregister_shrinker(&mp->m_inode_shrink);
 }