Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: use proper interfaces for on-stack plugging
  xfs: fix xfs_debug warnings
  xfs: fix variable set but not used warnings
  xfs: convert log tail checking to a warning
  xfs: catch bad block numbers freeing extents.
  xfs: push the AIL from memory reclaim and periodic sync
  xfs: clean up code layout in xfs_trans_ail.c
  xfs: convert the xfsaild threads to a workqueue
  xfs: introduce background inode reclaim work
  xfs: convert ENOSPC inode flushing to use new syncd workqueue
  xfs: introduce a xfssyncd workqueue
  xfs: fix extent format buffer allocation size
  xfs: fix unreferenced var error in xfs_buf.c

Also, applied patch from Tony Luck that fixes ia64:
  xfs_destroy_workqueues() should not be tagged with__exit
in the branch before merging.

17 files changed, 531 insertions, 507 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 5ea402023ebd..9ef9ed2cfe2e 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -293,7 +293,6 @@ xfs_buf_allocate_memory(
         size_t                  nbytes, offset;
         gfp_t                   gfp_mask = xb_to_gfp(flags);
         unsigned short          page_count, i;
-        pgoff_t                 first;
         xfs_off_t               end;
         int                     error;
 
@@ -333,7 +332,6 @@ use_alloc_page:
                 return error;
 
         offset = bp->b_offset;
-        first = bp->b_file_offset >> PAGE_SHIFT;
         bp->b_flags |= _XBF_PAGES;
 
         for (i = 0; i < bp->b_page_count; i++) {
@@ -657,8 +655,6 @@ xfs_buf_readahead(
         xfs_off_t               ioff,
         size_t                  isize)
 {
-        struct backing_dev_info *bdi;
-
         if (bdi_read_congested(target->bt_bdi))
                 return;
 
@@ -919,8 +915,6 @@ xfs_buf_lock(
 
         if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE))
                 xfs_log_force(bp->b_target->bt_mount, 0);
-        if (atomic_read(&bp->b_io_remaining))
-                blk_flush_plug(current);
         down(&bp->b_sema);
         XB_SET_OWNER(bp);
 
@@ -1309,8 +1303,6 @@ xfs_buf_iowait(
 {
         trace_xfs_buf_iowait(bp, _RET_IP_);
 
-        if (atomic_read(&bp->b_io_remaining))
-                blk_flush_plug(current);
         wait_for_completion(&bp->b_iowait);
 
         trace_xfs_buf_iowait_done(bp, _RET_IP_);
@@ -1747,8 +1739,8 @@ xfsbufd(
         do {
                 long    age = xfs_buf_age_centisecs * msecs_to_jiffies(10);
                 long    tout = xfs_buf_timer_centisecs * msecs_to_jiffies(10);
-                int     count = 0;
                 struct list_head tmp;
+                struct blk_plug plug;
 
                 if (unlikely(freezing(current))) {
                         set_bit(XBT_FORCE_SLEEP, &target->bt_flags);
@@ -1764,16 +1756,15 @@ xfsbufd(
 
                 xfs_buf_delwri_split(target, &tmp, age);
                 list_sort(NULL, &tmp, xfs_buf_cmp);
+
+                blk_start_plug(&plug);
                 while (!list_empty(&tmp)) {
                         struct xfs_buf *bp;
                         bp = list_first_entry(&tmp, struct xfs_buf, b_list);
                         list_del_init(&bp->b_list);
                         xfs_bdstrat_cb(bp);
-                        count++;
                 }
-                if (count)
-                        blk_flush_plug(current);
-
+                blk_finish_plug(&plug);
         } while (!kthread_should_stop());
 
         return 0;
@@ -1793,6 +1784,7 @@ xfs_flush_buftarg(
         int             pincount = 0;
         LIST_HEAD(tmp_list);
         LIST_HEAD(wait_list);
+        struct blk_plug plug;
 
         xfs_buf_runall_queues(xfsconvertd_workqueue);
         xfs_buf_runall_queues(xfsdatad_workqueue);
@@ -1807,6 +1799,8 @@ xfs_flush_buftarg(
          * we do that after issuing all the IO.
          */
         list_sort(NULL, &tmp_list, xfs_buf_cmp);
+
+        blk_start_plug(&plug);
         while (!list_empty(&tmp_list)) {
                 bp = list_first_entry(&tmp_list, struct xfs_buf, b_list);
                 ASSERT(target == bp->b_target);
@@ -1817,10 +1811,10 @@ xfs_flush_buftarg(
                 }
                 xfs_bdstrat_cb(bp);
         }
+        blk_finish_plug(&plug);
 
         if (wait) {
-                /* Expedite and wait for IO to complete. */
-                blk_flush_plug(current);
+                /* Wait for IO to complete. */
                 while (!list_empty(&wait_list)) {
                         bp = list_first_entry(&wait_list, struct xfs_buf, b_list);
 
diff --git a/fs/xfs/linux-2.6/xfs_message.c b/fs/xfs/linux-2.6/xfs_message.c
index 508e06fd7d1e..3ca795609113 100644
--- a/fs/xfs/linux-2.6/xfs_message.c
+++ b/fs/xfs/linux-2.6/xfs_message.c
@@ -28,53 +28,47 @@
 /*
  * XFS logging functions
  */
-static int
+static void
 __xfs_printk(
         const char              *level,
         const struct xfs_mount  *mp,
         struct va_format        *vaf)
 {
         if (mp && mp->m_fsname)
-                return printk("%sXFS (%s): %pV\n", level, mp->m_fsname, vaf);
-        return printk("%sXFS: %pV\n", level, vaf);
+                printk("%sXFS (%s): %pV\n", level, mp->m_fsname, vaf);
+        printk("%sXFS: %pV\n", level, vaf);
 }
 
-int xfs_printk(
+void xfs_printk(
         const char              *level,
         const struct xfs_mount  *mp,
         const char              *fmt, ...)
 {
         struct va_format        vaf;
         va_list                 args;
-        int                      r;
 
         va_start(args, fmt);
 
         vaf.fmt = fmt;
         vaf.va = &args;
 
-        r = __xfs_printk(level, mp, &vaf);
+        __xfs_printk(level, mp, &vaf);
         va_end(args);
-
-        return r;
 }
 
 #define define_xfs_printk_level(func, kern_level)               \
-int func(const struct xfs_mount *mp, const char *fmt, ...)      \
+void func(const struct xfs_mount *mp, const char *fmt, ...)     \
 {                                                               \
         struct va_format        vaf;                            \
         va_list                 args;                           \
-        int                     r;                              \
                                                                 \
         va_start(args, fmt);                                    \
                                                                 \
         vaf.fmt = fmt;                                          \
         vaf.va = &args;                                         \
                                                                 \
-        r = __xfs_printk(kern_level, mp, &vaf);                 \
+        __xfs_printk(kern_level, mp, &vaf);                     \
         va_end(args);                                           \
-                                                                \
-        return r;                                               \
 }                                                               \
 
 define_xfs_printk_level(xfs_emerg, KERN_EMERG);
@@ -88,7 +82,7 @@ define_xfs_printk_level(xfs_info, KERN_INFO);
 define_xfs_printk_level(xfs_debug, KERN_DEBUG);
 #endif
 
-int
+void
 xfs_alert_tag(
         const struct xfs_mount  *mp,
         int                     panic_tag,
@@ -97,7 +91,6 @@ xfs_alert_tag(
         struct va_format        vaf;
         va_list                 args;
         int                     do_panic = 0;
-        int                     r;
 
         if (xfs_panic_mask && (xfs_panic_mask & panic_tag)) {
                 xfs_printk(KERN_ALERT, mp,
@@ -110,12 +103,10 @@ xfs_alert_tag(
         vaf.fmt = fmt;
         vaf.va = &args;
 
-        r = __xfs_printk(KERN_ALERT, mp, &vaf);
+        __xfs_printk(KERN_ALERT, mp, &vaf);
         va_end(args);
 
         BUG_ON(do_panic);
-
-        return r;
 }
 
 void
diff --git a/fs/xfs/linux-2.6/xfs_message.h b/fs/xfs/linux-2.6/xfs_message.h
index e77ffa16745b..f1b3fc1b6c4e 100644
--- a/fs/xfs/linux-2.6/xfs_message.h
+++ b/fs/xfs/linux-2.6/xfs_message.h
@@ -3,32 +3,34 @@
 
 struct xfs_mount;
 
-extern int xfs_printk(const char *level, const struct xfs_mount *mp,
+extern void xfs_printk(const char *level, const struct xfs_mount *mp,
                       const char *fmt, ...)
         __attribute__ ((format (printf, 3, 4)));
-extern int xfs_emerg(const struct xfs_mount *mp, const char *fmt, ...)
+extern void xfs_emerg(const struct xfs_mount *mp, const char *fmt, ...)
         __attribute__ ((format (printf, 2, 3)));
-extern int xfs_alert(const struct xfs_mount *mp, const char *fmt, ...)
+extern void xfs_alert(const struct xfs_mount *mp, const char *fmt, ...)
         __attribute__ ((format (printf, 2, 3)));
-extern int xfs_alert_tag(const struct xfs_mount *mp, int tag,
+extern void xfs_alert_tag(const struct xfs_mount *mp, int tag,
                          const char *fmt, ...)
         __attribute__ ((format (printf, 3, 4)));
-extern int xfs_crit(const struct xfs_mount *mp, const char *fmt, ...)
+extern void xfs_crit(const struct xfs_mount *mp, const char *fmt, ...)
         __attribute__ ((format (printf, 2, 3)));
-extern int xfs_err(const struct xfs_mount *mp, const char *fmt, ...)
+extern void xfs_err(const struct xfs_mount *mp, const char *fmt, ...)
         __attribute__ ((format (printf, 2, 3)));
-extern int xfs_warn(const struct xfs_mount *mp, const char *fmt, ...)
+extern void xfs_warn(const struct xfs_mount *mp, const char *fmt, ...)
         __attribute__ ((format (printf, 2, 3)));
-extern int xfs_notice(const struct xfs_mount *mp, const char *fmt, ...)
+extern void xfs_notice(const struct xfs_mount *mp, const char *fmt, ...)
         __attribute__ ((format (printf, 2, 3)));
-extern int xfs_info(const struct xfs_mount *mp, const char *fmt, ...)
+extern void xfs_info(const struct xfs_mount *mp, const char *fmt, ...)
         __attribute__ ((format (printf, 2, 3)));
 
 #ifdef DEBUG
-extern int xfs_debug(const struct xfs_mount *mp, const char *fmt, ...)
+extern void xfs_debug(const struct xfs_mount *mp, const char *fmt, ...)
         __attribute__ ((format (printf, 2, 3)));
 #else
-#define xfs_debug(mp, fmt, ...) (0)
+static inline void xfs_debug(const struct xfs_mount *mp, const char *fmt, ...)
+{
+}
 #endif
 
 extern void assfail(char *expr, char *f, int l);
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 1ba5c451da36..b38e58d02299 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -816,75 +816,6 @@ xfs_setup_devices(
         return 0;
 }
 
-/*
- * XFS AIL push thread support
- */
-void
-xfsaild_wakeup(
-        struct xfs_ail          *ailp,
-        xfs_lsn_t               threshold_lsn)
-{
-        /* only ever move the target forwards */
-        if (XFS_LSN_CMP(threshold_lsn, ailp->xa_target) > 0) {
-                ailp->xa_target = threshold_lsn;
-                wake_up_process(ailp->xa_task);
-        }
-}
-
-STATIC int
-xfsaild(
-        void    *data)
-{
-        struct xfs_ail  *ailp = data;
-        xfs_lsn_t       last_pushed_lsn = 0;
-        long            tout = 0; /* milliseconds */
-
-        while (!kthread_should_stop()) {
-                /*
-                 * for short sleeps indicating congestion, don't allow us to
-                 * get woken early. Otherwise all we do is bang on the AIL lock
-                 * without making progress.
-                 */
-                if (tout && tout <= 20)
-                        __set_current_state(TASK_KILLABLE);
-                else
-                        __set_current_state(TASK_INTERRUPTIBLE);
-                schedule_timeout(tout ?
-                                 msecs_to_jiffies(tout) : MAX_SCHEDULE_TIMEOUT);
-
-                /* swsusp */
-                try_to_freeze();
-
-                ASSERT(ailp->xa_mount->m_log);
-                if (XFS_FORCED_SHUTDOWN(ailp->xa_mount))
-                        continue;
-
-                tout = xfsaild_push(ailp, &last_pushed_lsn);
-        }
-
-        return 0;
-}       /* xfsaild */
-
-int
-xfsaild_start(
-        struct xfs_ail  *ailp)
-{
-        ailp->xa_target = 0;
-        ailp->xa_task = kthread_run(xfsaild, ailp, "xfsaild/%s",
-                                    ailp->xa_mount->m_fsname);
-        if (IS_ERR(ailp->xa_task))
-                return -PTR_ERR(ailp->xa_task);
-        return 0;
-}
-
-void
-xfsaild_stop(
-        struct xfs_ail  *ailp)
-{
-        kthread_stop(ailp->xa_task);
-}
-
-
 /* Catch misguided souls that try to use this interface on XFS */
 STATIC struct inode *
 xfs_fs_alloc_inode(
@@ -1191,22 +1122,12 @@ xfs_fs_sync_fs(
                 return -error;
 
         if (laptop_mode) {
-                int     prev_sync_seq = mp->m_sync_seq;
-
                 /*
                  * The disk must be active because we're syncing.
                  * We schedule xfssyncd now (now that the disk is
                  * active) instead of later (when it might not be).
                  */
-                wake_up_process(mp->m_sync_task);
-                /*
-                 * We have to wait for the sync iteration to complete.
-                 * If we don't, the disk activity caused by the sync
-                 * will come after the sync is completed, and that
-                 * triggers another sync from laptop mode.
-                 */
-                wait_event(mp->m_wait_single_sync_task,
-                                mp->m_sync_seq != prev_sync_seq);
+                flush_delayed_work_sync(&mp->m_sync_work);
         }
 
         return 0;
@@ -1490,9 +1411,6 @@ xfs_fs_fill_super(
         spin_lock_init(&mp->m_sb_lock);
         mutex_init(&mp->m_growlock);
         atomic_set(&mp->m_active_trans, 0);
-        INIT_LIST_HEAD(&mp->m_sync_list);
-        spin_lock_init(&mp->m_sync_lock);
-        init_waitqueue_head(&mp->m_wait_single_sync_task);
 
         mp->m_super = sb;
         sb->s_fs_info = mp;
@@ -1799,6 +1717,38 @@ xfs_destroy_zones(void)
 }
 
 STATIC int __init
+xfs_init_workqueues(void)
+{
+        /*
+         * max_active is set to 8 to give enough concurency to allow
+         * multiple work operations on each CPU to run. This allows multiple
+         * filesystems to be running sync work concurrently, and scales with
+         * the number of CPUs in the system.
+         */
+        xfs_syncd_wq = alloc_workqueue("xfssyncd", WQ_CPU_INTENSIVE, 8);
+        if (!xfs_syncd_wq)
+                goto out;
+
+        xfs_ail_wq = alloc_workqueue("xfsail", WQ_CPU_INTENSIVE, 8);
+        if (!xfs_ail_wq)
+                goto out_destroy_syncd;
+
+        return 0;
+
+out_destroy_syncd:
+        destroy_workqueue(xfs_syncd_wq);
+out:
+        return -ENOMEM;
+}
+
+STATIC void
+xfs_destroy_workqueues(void)
+{
+        destroy_workqueue(xfs_ail_wq);
+        destroy_workqueue(xfs_syncd_wq);
+}
+
+STATIC int __init
 init_xfs_fs(void)
 {
         int                     error;
@@ -1813,10 +1763,14 @@ init_xfs_fs(void)
         if (error)
                 goto out;
 
-        error = xfs_mru_cache_init();
+        error = xfs_init_workqueues();
         if (error)
                 goto out_destroy_zones;
 
+        error = xfs_mru_cache_init();
+        if (error)
+                goto out_destroy_wq;
+
         error = xfs_filestream_init();
         if (error)
                 goto out_mru_cache_uninit;
@@ -1833,6 +1787,10 @@ init_xfs_fs(void)
         if (error)
                 goto out_cleanup_procfs;
 
+        error = xfs_init_workqueues();
+        if (error)
+                goto out_sysctl_unregister;
+
         vfs_initquota();
 
         error = register_filesystem(&xfs_fs_type);
@@ -1850,6 +1808,8 @@ init_xfs_fs(void)
         xfs_filestream_uninit();
  out_mru_cache_uninit:
         xfs_mru_cache_uninit();
+ out_destroy_wq:
+        xfs_destroy_workqueues();
  out_destroy_zones:
         xfs_destroy_zones();
  out:
@@ -1866,6 +1826,7 @@ exit_xfs_fs(void)
         xfs_buf_terminate();
         xfs_filestream_uninit();
         xfs_mru_cache_uninit();
+        xfs_destroy_workqueues();
         xfs_destroy_zones();
 }
 
diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c
index 9cf35a688f53..e4f9c1b0836c 100644
--- a/fs/xfs/linux-2.6/xfs_sync.c
+++ b/fs/xfs/linux-2.6/xfs_sync.c
@@ -22,6 +22,7 @@
 #include "xfs_log.h"
 #include "xfs_inum.h"
 #include "xfs_trans.h"
+#include "xfs_trans_priv.h"
 #include "xfs_sb.h"
 #include "xfs_ag.h"
 #include "xfs_mount.h"
@@ -39,6 +40,8 @@
 #include <linux/kthread.h>
 #include <linux/freezer.h>
 
+struct workqueue_struct *xfs_syncd_wq;  /* sync workqueue */
+
 /*
  * The inode lookup is done in batches to keep the amount of lock traffic and
  * radix tree lookups to a minimum. The batch size is a trade off between
@@ -431,62 +434,12 @@ xfs_quiesce_attr(
         xfs_unmountfs_writesb(mp);
 }
 
-/*
- * Enqueue a work item to be picked up by the vfs xfssyncd thread.
- * Doing this has two advantages:
- * - It saves on stack space, which is tight in certain situations
- * - It can be used (with care) as a mechanism to avoid deadlocks.
- * Flushing while allocating in a full filesystem requires both.
- */
-STATIC void
-xfs_syncd_queue_work(
-        struct xfs_mount *mp,
-        void            *data,
-        void            (*syncer)(struct xfs_mount *, void *),
-        struct completion *completion)
-{
-        struct xfs_sync_work *work;
-
-        work = kmem_alloc(sizeof(struct xfs_sync_work), KM_SLEEP);
-        INIT_LIST_HEAD(&work->w_list);
-        work->w_syncer = syncer;
-        work->w_data = data;
-        work->w_mount = mp;
-        work->w_completion = completion;
-        spin_lock(&mp->m_sync_lock);
-        list_add_tail(&work->w_list, &mp->m_sync_list);
-        spin_unlock(&mp->m_sync_lock);
-        wake_up_process(mp->m_sync_task);
-}
-
-/*
- * Flush delayed allocate data, attempting to free up reserved space
- * from existing allocations.  At this point a new allocation attempt
- * has failed with ENOSPC and we are in the process of scratching our
- * heads, looking about for more room...
- */
-STATIC void
-xfs_flush_inodes_work(
-        struct xfs_mount *mp,
-        void            *arg)
-{
-        struct inode    *inode = arg;
-        xfs_sync_data(mp, SYNC_TRYLOCK);
-        xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_WAIT);
-        iput(inode);
-}
-
-void
-xfs_flush_inodes(
-        xfs_inode_t     *ip)
+static void
+xfs_syncd_queue_sync(
+        struct xfs_mount        *mp)
 {
-        struct inode    *inode = VFS_I(ip);
-        DECLARE_COMPLETION_ONSTACK(completion);
-
-        igrab(inode);
-        xfs_syncd_queue_work(ip->i_mount, inode, xfs_flush_inodes_work, &completion);
-        wait_for_completion(&completion);
-        xfs_log_force(ip->i_mount, XFS_LOG_SYNC);
+        queue_delayed_work(xfs_syncd_wq, &mp->m_sync_work,
+                                msecs_to_jiffies(xfs_syncd_centisecs * 10));
 }
 
 /*
@@ -496,9 +449,10 @@ xfs_flush_inodes(
  */
 STATIC void
 xfs_sync_worker(
-        struct xfs_mount *mp,
-        void            *unused)
+        struct work_struct *work)
 {
+        struct xfs_mount *mp = container_of(to_delayed_work(work),
+                                        struct xfs_mount, m_sync_work);
         int             error;
 
         if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
@@ -508,73 +462,106 @@ xfs_sync_worker(
                         error = xfs_fs_log_dummy(mp);
                 else
                         xfs_log_force(mp, 0);
-                xfs_reclaim_inodes(mp, 0);
                 error = xfs_qm_sync(mp, SYNC_TRYLOCK);
+
+                /* start pushing all the metadata that is currently dirty */
+                xfs_ail_push_all(mp->m_ail);
         }
-        mp->m_sync_seq++;
-        wake_up(&mp->m_wait_single_sync_task);
+
+        /* queue us up again */
+        xfs_syncd_queue_sync(mp);
 }
 
-STATIC int
-xfssyncd(
-        void                    *arg)
+/*
+ * Queue a new inode reclaim pass if there are reclaimable inodes and there
+ * isn't a reclaim pass already in progress. By default it runs every 5s based
+ * on the xfs syncd work default of 30s. Perhaps this should have it's own
+ * tunable, but that can be done if this method proves to be ineffective or too
+ * aggressive.
+ */
+static void
+xfs_syncd_queue_reclaim(
+        struct xfs_mount        *mp)
 {
-        struct xfs_mount        *mp = arg;
-        long                    timeleft;
-        xfs_sync_work_t         *work, *n;
-        LIST_HEAD               (tmp);
-
-        set_freezable();
-        timeleft = xfs_syncd_centisecs * msecs_to_jiffies(10);
-        for (;;) {
-                if (list_empty(&mp->m_sync_list))
-                        timeleft = schedule_timeout_interruptible(timeleft);
-                /* swsusp */
-                try_to_freeze();
-                if (kthread_should_stop() && list_empty(&mp->m_sync_list))
-                        break;
 
-                spin_lock(&mp->m_sync_lock);
-                /*
-                 * We can get woken by laptop mode, to do a sync -
-                 * that's the (only!) case where the list would be
-                 * empty with time remaining.
-                 */
-                if (!timeleft || list_empty(&mp->m_sync_list)) {
-                        if (!timeleft)
-                                timeleft = xfs_syncd_centisecs *
-                                                        msecs_to_jiffies(10);
-                        INIT_LIST_HEAD(&mp->m_sync_work.w_list);
-                        list_add_tail(&mp->m_sync_work.w_list,
-                                        &mp->m_sync_list);
-                }
-                list_splice_init(&mp->m_sync_list, &tmp);
-                spin_unlock(&mp->m_sync_lock);
+        /*
+         * We can have inodes enter reclaim after we've shut down the syncd
+         * workqueue during unmount, so don't allow reclaim work to be queued
+         * during unmount.
+         */
+        if (!(mp->m_super->s_flags & MS_ACTIVE))
+                return;
 
-                list_for_each_entry_safe(work, n, &tmp, w_list) {
-                        (*work->w_syncer)(mp, work->w_data);
-                        list_del(&work->w_list);
-                        if (work == &mp->m_sync_work)
-                                continue;
-                        if (work->w_completion)
-                                complete(work->w_completion);
-                        kmem_free(work);
-                }
+        rcu_read_lock();
+        if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
+                queue_delayed_work(xfs_syncd_wq, &mp->m_reclaim_work,
+                        msecs_to_jiffies(xfs_syncd_centisecs / 6 * 10));
         }
+        rcu_read_unlock();
+}
 
-        return 0;
+/*
+ * This is a fast pass over the inode cache to try to get reclaim moving on as
+ * many inodes as possible in a short period of time. It kicks itself every few
+ * seconds, as well as being kicked by the inode cache shrinker when memory
+ * goes low. It scans as quickly as possible avoiding locked inodes or those
+ * already being flushed, and once done schedules a future pass.
+ */
+STATIC void
+xfs_reclaim_worker(
+        struct work_struct *work)
+{
+        struct xfs_mount *mp = container_of(to_delayed_work(work),
+                                        struct xfs_mount, m_reclaim_work);
+
+        xfs_reclaim_inodes(mp, SYNC_TRYLOCK);
+        xfs_syncd_queue_reclaim(mp);
+}
+
+/*
+ * Flush delayed allocate data, attempting to free up reserved space
+ * from existing allocations.  At this point a new allocation attempt
+ * has failed with ENOSPC and we are in the process of scratching our
+ * heads, looking about for more room.
+ *
+ * Queue a new data flush if there isn't one already in progress and
+ * wait for completion of the flush. This means that we only ever have one
+ * inode flush in progress no matter how many ENOSPC events are occurring and
+ * so will prevent the system from bogging down due to every concurrent
+ * ENOSPC event scanning all the active inodes in the system for writeback.
+ */
+void
+xfs_flush_inodes(
+        struct xfs_inode        *ip)
+{
+        struct xfs_mount        *mp = ip->i_mount;
+
+        queue_work(xfs_syncd_wq, &mp->m_flush_work);
+        flush_work_sync(&mp->m_flush_work);
+}
+
+STATIC void
+xfs_flush_worker(
+        struct work_struct *work)
+{
+        struct xfs_mount *mp = container_of(work,
+                                        struct xfs_mount, m_flush_work);
+
+        xfs_sync_data(mp, SYNC_TRYLOCK);
+        xfs_sync_data(mp, SYNC_TRYLOCK | SYNC_WAIT);
 }
 
 int
 xfs_syncd_init(
         struct xfs_mount        *mp)
 {
-        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/%s", mp->m_fsname);
-        if (IS_ERR(mp->m_sync_task))
-                return -PTR_ERR(mp->m_sync_task);
+        INIT_WORK(&mp->m_flush_work, xfs_flush_worker);
+        INIT_DELAYED_WORK(&mp->m_sync_work, xfs_sync_worker);
+        INIT_DELAYED_WORK(&mp->m_reclaim_work, xfs_reclaim_worker);
+
+        xfs_syncd_queue_sync(mp);
+        xfs_syncd_queue_reclaim(mp);
+
         return 0;
 }
 
@@ -582,7 +569,9 @@ void
 xfs_syncd_stop(
         struct xfs_mount        *mp)
 {
-        kthread_stop(mp->m_sync_task);
+        cancel_delayed_work_sync(&mp->m_sync_work);
+        cancel_delayed_work_sync(&mp->m_reclaim_work);
+        cancel_work_sync(&mp->m_flush_work);
 }
 
 void
@@ -601,6 +590,10 @@ __xfs_inode_set_reclaim_tag(
                                 XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
                                 XFS_ICI_RECLAIM_TAG);
                 spin_unlock(&ip->i_mount->m_perag_lock);
+
+                /* schedule periodic background inode reclaim */
+                xfs_syncd_queue_reclaim(ip->i_mount);
+
                 trace_xfs_perag_set_reclaim(ip->i_mount, pag->pag_agno,
                                                         -1, _RET_IP_);
         }
@@ -1017,7 +1010,13 @@ xfs_reclaim_inodes(
 }
 
 /*
- * Shrinker infrastructure.
+ * Inode cache shrinker.
+ *
+ * When called we make sure that there is a background (fast) inode reclaim in
+ * progress, while we will throttle the speed of reclaim via doiing synchronous
+ * reclaim of inodes. That means if we come across dirty inodes, we wait for
+ * them to be cleaned, which we hope will not be very long due to the
+ * background walker having already kicked the IO off on those dirty inodes.
  */
 static int
 xfs_reclaim_inode_shrink(
@@ -1032,10 +1031,15 @@ xfs_reclaim_inode_shrink(
 
         mp = container_of(shrink, struct xfs_mount, m_inode_shrink);
         if (nr_to_scan) {
+                /* kick background reclaimer and push the AIL */
+                xfs_syncd_queue_reclaim(mp);
+                xfs_ail_push_all(mp->m_ail);
+
                 if (!(gfp_mask & __GFP_FS))
                         return -1;
 
-                xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK, &nr_to_scan);
+                xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT,
+                                        &nr_to_scan);
                 /* terminate if we don't exhaust the scan */
                 if (nr_to_scan > 0)
                         return -1;
diff --git a/fs/xfs/linux-2.6/xfs_sync.h b/fs/xfs/linux-2.6/xfs_sync.h
index 32ba6628290c..e3a6ad27415f 100644
--- a/fs/xfs/linux-2.6/xfs_sync.h
+++ b/fs/xfs/linux-2.6/xfs_sync.h
@@ -32,6 +32,8 @@ typedef struct xfs_sync_work {
 #define SYNC_WAIT               0x0001  /* wait for i/o to complete */
 #define SYNC_TRYLOCK            0x0002  /* only try to lock inodes */
 
+extern struct workqueue_struct  *xfs_syncd_wq;  /* sync workqueue */
+
 int xfs_syncd_init(struct xfs_mount *mp);
 void xfs_syncd_stop(struct xfs_mount *mp);
 
diff --git a/fs/xfs/quota/xfs_qm.c b/fs/xfs/quota/xfs_qm.c
index 254ee062bd7d..69228aa8605a 100644
--- a/fs/xfs/quota/xfs_qm.c
+++ b/fs/xfs/quota/xfs_qm.c
@@ -461,12 +461,10 @@ xfs_qm_dqflush_all(
         struct xfs_quotainfo    *q = mp->m_quotainfo;
         int                     recl;
         struct xfs_dquot        *dqp;
-        int                     niters;
         int                     error;
 
         if (!q)
                 return 0;
-        niters = 0;
 again:
         mutex_lock(&q->qi_dqlist_lock);
         list_for_each_entry(dqp, &q->qi_dqlist, q_mplist) {
@@ -1314,14 +1312,9 @@ xfs_qm_dqiter_bufs(
 {
         xfs_buf_t       *bp;
         int             error;
-        int             notcommitted;
-        int             incr;
         int             type;
 
         ASSERT(blkcnt > 0);
-        notcommitted = 0;
-        incr = (blkcnt > XFS_QM_MAX_DQCLUSTER_LOGSZ) ?
-                XFS_QM_MAX_DQCLUSTER_LOGSZ : blkcnt;
         type = flags & XFS_QMOPT_UQUOTA ? XFS_DQ_USER :
                 (flags & XFS_QMOPT_PQUOTA ? XFS_DQ_PROJ : XFS_DQ_GROUP);
         error = 0;
diff --git a/fs/xfs/quota/xfs_qm.h b/fs/xfs/quota/xfs_qm.h
index c9446f1c726d..567b29b9f1b3 100644
--- a/fs/xfs/quota/xfs_qm.h
+++ b/fs/xfs/quota/xfs_qm.h
@@ -65,11 +65,6 @@ extern kmem_zone_t	*qm_dqtrxzone;
  * block in the dquot/xqm code.
  */
 #define XFS_DQUOT_CLUSTER_SIZE_FSB      (xfs_filblks_t)1
-/*
- * When doing a quotacheck, we log dquot clusters of this many FSBs at most
- * in a single transaction. We don't want to ask for too huge a log reservation.
- */
-#define XFS_QM_MAX_DQCLUSTER_LOGSZ      3
 
 typedef xfs_dqhash_t    xfs_dqlist_t;
 
diff --git a/fs/xfs/quota/xfs_qm_syscalls.c b/fs/xfs/quota/xfs_qm_syscalls.c
index 0d62a07b7fd8..2dadb15d5ca9 100644
--- a/fs/xfs/quota/xfs_qm_syscalls.c
+++ b/fs/xfs/quota/xfs_qm_syscalls.c
@@ -313,14 +313,12 @@ xfs_qm_scall_quotaon(
 {
         int             error;
         uint            qf;
-        uint            accflags;
         __int64_t       sbflags;
 
         flags &= (XFS_ALL_QUOTA_ACCT | XFS_ALL_QUOTA_ENFD);
         /*
          * Switching on quota accounting must be done at mount time.
          */
-        accflags = flags & XFS_ALL_QUOTA_ACCT;
         flags &= ~(XFS_ALL_QUOTA_ACCT);
 
         sbflags = 0;
diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 4bc3c649aee4..27d64d752eab 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -2395,17 +2395,33 @@ xfs_free_extent(
         memset(&args, 0, sizeof(xfs_alloc_arg_t));
         args.tp = tp;
         args.mp = tp->t_mountp;
+
+        /*
+         * validate that the block number is legal - the enables us to detect
+         * and handle a silent filesystem corruption rather than crashing.
+         */
         args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
-        ASSERT(args.agno < args.mp->m_sb.sb_agcount);
+        if (args.agno >= args.mp->m_sb.sb_agcount)
+                return EFSCORRUPTED;
+
         args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
+        if (args.agbno >= args.mp->m_sb.sb_agblocks)
+                return EFSCORRUPTED;
+
         args.pag = xfs_perag_get(args.mp, args.agno);
-        if ((error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING)))
+        ASSERT(args.pag);
+
+        error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
+        if (error)
                 goto error0;
-#ifdef DEBUG
-        ASSERT(args.agbp != NULL);
-        ASSERT((args.agbno + len) <=
-                be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length));
-#endif
+
+        /* validate the extent size is legal now we have the agf locked */
+        if (args.agbno + len >
+                        be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) {
+                error = EFSCORRUPTED;
+                goto error0;
+        }
+
         error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
 error0:
         xfs_perag_put(args.pag);
diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index 46cc40131d4a..576fdfe81d60 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -198,6 +198,41 @@ xfs_inode_item_size(
 }
 
 /*
+ * xfs_inode_item_format_extents - convert in-core extents to on-disk form
+ *
+ * For either the data or attr fork in extent format, we need to endian convert
+ * the in-core extent as we place them into the on-disk inode. In this case, we
+ * need to do this conversion before we write the extents into the log. Because
+ * we don't have the disk inode to write into here, we allocate a buffer and
+ * format the extents into it via xfs_iextents_copy(). We free the buffer in
+ * the unlock routine after the copy for the log has been made.
+ *
+ * In the case of the data fork, the in-core and on-disk fork sizes can be
+ * different due to delayed allocation extents. We only log on-disk extents
+ * here, so always use the physical fork size to determine the size of the
+ * buffer we need to allocate.
+ */
+STATIC void
+xfs_inode_item_format_extents(
+        struct xfs_inode        *ip,
+        struct xfs_log_iovec    *vecp,
+        int                     whichfork,
+        int                     type)
+{
+        xfs_bmbt_rec_t          *ext_buffer;
+
+        ext_buffer = kmem_alloc(XFS_IFORK_SIZE(ip, whichfork), KM_SLEEP);
+        if (whichfork == XFS_DATA_FORK)
+                ip->i_itemp->ili_extents_buf = ext_buffer;
+        else
+                ip->i_itemp->ili_aextents_buf = ext_buffer;
+
+        vecp->i_addr = ext_buffer;
+        vecp->i_len = xfs_iextents_copy(ip, ext_buffer, whichfork);
+        vecp->i_type = type;
+}
+
+/*
  * This is called to fill in the vector of log iovecs for the
  * given inode log item.  It fills the first item with an inode
  * log format structure, the second with the on-disk inode structure,
@@ -213,7 +248,6 @@ xfs_inode_item_format(
         struct xfs_inode        *ip = iip->ili_inode;
         uint                    nvecs;
         size_t                  data_bytes;
-        xfs_bmbt_rec_t          *ext_buffer;
         xfs_mount_t             *mp;
 
         vecp->i_addr = &iip->ili_format;
@@ -320,22 +354,8 @@ xfs_inode_item_format(
                         } else
 #endif
                         {
-                                /*
-                                 * There are delayed allocation extents
-                                 * in the inode, or we need to convert
-                                 * the extents to on disk format.
-                                 * Use xfs_iextents_copy()
-                                 * to copy only the real extents into
-                                 * a separate buffer.  We'll free the
-                                 * buffer in the unlock routine.
-                                 */
-                                ext_buffer = kmem_alloc(ip->i_df.if_bytes,
-                                        KM_SLEEP);
-                                iip->ili_extents_buf = ext_buffer;
-                                vecp->i_addr = ext_buffer;
-                                vecp->i_len = xfs_iextents_copy(ip, ext_buffer,
-                                                XFS_DATA_FORK);
-                                vecp->i_type = XLOG_REG_TYPE_IEXT;
+                                xfs_inode_item_format_extents(ip, vecp,
+                                        XFS_DATA_FORK, XLOG_REG_TYPE_IEXT);
                         }
                         ASSERT(vecp->i_len <= ip->i_df.if_bytes);
                         iip->ili_format.ilf_dsize = vecp->i_len;
@@ -445,19 +465,12 @@ xfs_inode_item_format(
                          */
                         vecp->i_addr = ip->i_afp->if_u1.if_extents;
                         vecp->i_len = ip->i_afp->if_bytes;
+                        vecp->i_type = XLOG_REG_TYPE_IATTR_EXT;
 #else
                         ASSERT(iip->ili_aextents_buf == NULL);
-                        /*
-                         * Need to endian flip before logging
-                         */
-                        ext_buffer = kmem_alloc(ip->i_afp->if_bytes,
-                                KM_SLEEP);
-                        iip->ili_aextents_buf = ext_buffer;
-                        vecp->i_addr = ext_buffer;
-                        vecp->i_len = xfs_iextents_copy(ip, ext_buffer,
-                                        XFS_ATTR_FORK);
+                        xfs_inode_item_format_extents(ip, vecp,
+                                        XFS_ATTR_FORK, XLOG_REG_TYPE_IATTR_EXT);
 #endif
-                        vecp->i_type = XLOG_REG_TYPE_IATTR_EXT;
                         iip->ili_format.ilf_asize = vecp->i_len;
                         vecp++;
                         nvecs++;
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index dc1882adaf54..751e94fe1f77 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -204,7 +204,6 @@ xfs_bulkstat(
         xfs_agi_t               *agi;   /* agi header data */
         xfs_agino_t             agino;  /* inode # in allocation group */
         xfs_agnumber_t          agno;   /* allocation group number */
-        xfs_daddr_t             bno;    /* inode cluster start daddr */
         int                     chunkidx; /* current index into inode chunk */
         int                     clustidx; /* current index into inode cluster */
         xfs_btree_cur_t         *cur;   /* btree cursor for ialloc btree */
@@ -463,7 +462,6 @@ xfs_bulkstat(
                                                  mp->m_sb.sb_inopblog);
                                 }
                                 ino = XFS_AGINO_TO_INO(mp, agno, agino);
-                                bno = XFS_AGB_TO_DADDR(mp, agno, agbno);
                                 /*
                                  * Skip if this inode is free.
                                  */
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 25efa9b8a602..b612ce4520ae 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -761,7 +761,7 @@ xfs_log_need_covered(xfs_mount_t *mp)
                 break;
         case XLOG_STATE_COVER_NEED:
         case XLOG_STATE_COVER_NEED2:
-                if (!xfs_trans_ail_tail(log->l_ailp) &&
+                if (!xfs_ail_min_lsn(log->l_ailp) &&
                     xlog_iclogs_empty(log)) {
                         if (log->l_covered_state == XLOG_STATE_COVER_NEED)
                                 log->l_covered_state = XLOG_STATE_COVER_DONE;
@@ -801,7 +801,7 @@ xlog_assign_tail_lsn(
         xfs_lsn_t               tail_lsn;
         struct log              *log = mp->m_log;
 
-        tail_lsn = xfs_trans_ail_tail(mp->m_ail);
+        tail_lsn = xfs_ail_min_lsn(mp->m_ail);
         if (!tail_lsn)
                 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
 
@@ -1239,7 +1239,7 @@ xlog_grant_push_ail(
          * the filesystem is shutting down.
          */
         if (!XLOG_FORCED_SHUTDOWN(log))
-                xfs_trans_ail_push(log->l_ailp, threshold_lsn);
+                xfs_ail_push(log->l_ailp, threshold_lsn);
 }
 
 /*
@@ -3407,6 +3407,17 @@ xlog_verify_dest_ptr(
                 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
 }
 
+/*
+ * Check to make sure the grant write head didn't just over lap the tail.  If
+ * the cycles are the same, we can't be overlapping.  Otherwise, make sure that
+ * the cycles differ by exactly one and check the byte count.
+ *
+ * This check is run unlocked, so can give false positives. Rather than assert
+ * on failures, use a warn-once flag and a panic tag to allow the admin to
+ * determine if they want to panic the machine when such an error occurs. For
+ * debug kernels this will have the same effect as using an assert but, unlinke
+ * an assert, it can be turned off at runtime.
+ */
 STATIC void
 xlog_verify_grant_tail(
         struct log      *log)
@@ -3414,17 +3425,22 @@ xlog_verify_grant_tail(
         int             tail_cycle, tail_blocks;
         int             cycle, space;
 
-        /*
-         * Check to make sure the grant write head didn't just over lap the
-         * tail.  If the cycles are the same, we can't be overlapping.
-         * Otherwise, make sure that the cycles differ by exactly one and
-         * check the byte count.
-         */
         xlog_crack_grant_head(&log->l_grant_write_head, &cycle, &space);
         xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
         if (tail_cycle != cycle) {
-                ASSERT(cycle - 1 == tail_cycle);
-                ASSERT(space <= BBTOB(tail_blocks));
+                if (cycle - 1 != tail_cycle &&
+                    !(log->l_flags & XLOG_TAIL_WARN)) {
+                        xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
+                                "%s: cycle - 1 != tail_cycle", __func__);
+                        log->l_flags |= XLOG_TAIL_WARN;
+                }
+
+                if (space > BBTOB(tail_blocks) &&
+                    !(log->l_flags & XLOG_TAIL_WARN)) {
+                        xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
+                                "%s: space > BBTOB(tail_blocks)", __func__);
+                        log->l_flags |= XLOG_TAIL_WARN;
+                }
         }
 }
 
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index ffae692c9832..5864850e9e34 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -144,6 +144,7 @@ static inline uint xlog_get_client_id(__be32 i)
 #define XLOG_RECOVERY_NEEDED    0x4     /* log was recovered */
 #define XLOG_IO_ERROR           0x8     /* log hit an I/O error, and being
                                            shutdown */
+#define XLOG_TAIL_WARN          0x10    /* log tail verify warning issued */
 
 #ifdef __KERNEL__
 /*
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index a62e8971539d..19af0ab0d0c6 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -203,12 +203,9 @@ typedef struct xfs_mount {
         struct mutex            m_icsb_mutex;   /* balancer sync lock */
 #endif
         struct xfs_mru_cache    *m_filestream;  /* per-mount filestream data */
-        struct task_struct      *m_sync_task;   /* generalised sync thread */
-        xfs_sync_work_t         m_sync_work;    /* work item for VFS_SYNC */
-        struct list_head        m_sync_list;    /* sync thread work item list */
-        spinlock_t              m_sync_lock;    /* work item list lock */
-        int                     m_sync_seq;     /* sync thread generation no. */
-        wait_queue_head_t       m_wait_single_sync_task;
+        struct delayed_work     m_sync_work;    /* background sync work */
+        struct delayed_work     m_reclaim_work; /* background inode reclaim */
+        struct work_struct      m_flush_work;   /* background inode flush */
         __int64_t               m_update_flags; /* sb flags we need to update
                                                    on the next remount,rw */
         struct shrinker         m_inode_shrink; /* inode reclaim shrinker */
diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index 12aff9584e29..acdb92f14d51 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -28,74 +28,138 @@
 #include "xfs_trans_priv.h"
 #include "xfs_error.h"
 
-STATIC void xfs_ail_splice(struct xfs_ail *, struct list_head *, xfs_lsn_t);
-STATIC void xfs_ail_delete(struct xfs_ail *, xfs_log_item_t *);
-STATIC xfs_log_item_t * xfs_ail_min(struct xfs_ail *);
-STATIC xfs_log_item_t * xfs_ail_next(struct xfs_ail *, xfs_log_item_t *);
+struct workqueue_struct *xfs_ail_wq;    /* AIL workqueue */
 
 #ifdef DEBUG
-STATIC void xfs_ail_check(struct xfs_ail *, xfs_log_item_t *);
-#else
+/*
+ * Check that the list is sorted as it should be.
+ */
+STATIC void
+xfs_ail_check(
+        struct xfs_ail  *ailp,
+        xfs_log_item_t  *lip)
+{
+        xfs_log_item_t  *prev_lip;
+
+        if (list_empty(&ailp->xa_ail))
+                return;
+
+        /*
+         * Check the next and previous entries are valid.
+         */
+        ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
+        prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail);
+        if (&prev_lip->li_ail != &ailp->xa_ail)
+                ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
+
+        prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail);
+        if (&prev_lip->li_ail != &ailp->xa_ail)
+                ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0);
+
+
+#ifdef XFS_TRANS_DEBUG
+        /*
+         * Walk the list checking lsn ordering, and that every entry has the
+         * XFS_LI_IN_AIL flag set. This is really expensive, so only do it
+         * when specifically debugging the transaction subsystem.
+         */
+        prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
+        list_for_each_entry(lip, &ailp->xa_ail, li_ail) {
+                if (&prev_lip->li_ail != &ailp->xa_ail)
+                        ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
+                ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
+                prev_lip = lip;
+        }
+#endif /* XFS_TRANS_DEBUG */
+}
+#else /* !DEBUG */
 #define xfs_ail_check(a,l)
 #endif /* DEBUG */
 
+/*
+ * Return a pointer to the first item in the AIL.  If the AIL is empty, then
+ * return NULL.
+ */
+static xfs_log_item_t *
+xfs_ail_min(
+        struct xfs_ail  *ailp)
+{
+        if (list_empty(&ailp->xa_ail))
+                return NULL;
+
+        return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
+}
+
+ /*
+ * Return a pointer to the last item in the AIL.  If the AIL is empty, then
+ * return NULL.
+ */
+static xfs_log_item_t *
+xfs_ail_max(
+        struct xfs_ail  *ailp)
+{
+        if (list_empty(&ailp->xa_ail))
+                return NULL;
+
+        return list_entry(ailp->xa_ail.prev, xfs_log_item_t, li_ail);
+}
+
+/*
+ * Return a pointer to the item which follows the given item in the AIL.  If
+ * the given item is the last item in the list, then return NULL.
+ */
+static xfs_log_item_t *
+xfs_ail_next(
+        struct xfs_ail  *ailp,
+        xfs_log_item_t  *lip)
+{
+        if (lip->li_ail.next == &ailp->xa_ail)
+                return NULL;
+
+        return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail);
+}
 
 /*
- * This is called by the log manager code to determine the LSN
- * of the tail of the log.  This is exactly the LSN of the first
- * item in the AIL.  If the AIL is empty, then this function
- * returns 0.
+ * This is called by the log manager code to determine the LSN of the tail of
+ * the log.  This is exactly the LSN of the first item in the AIL.  If the AIL
+ * is empty, then this function returns 0.
  *
- * We need the AIL lock in order to get a coherent read of the
- * lsn of the last item in the AIL.
+ * We need the AIL lock in order to get a coherent read of the lsn of the last
+ * item in the AIL.
  */
 xfs_lsn_t
-xfs_trans_ail_tail(
+xfs_ail_min_lsn(
         struct xfs_ail  *ailp)
 {
-        xfs_lsn_t       lsn;
+        xfs_lsn_t       lsn = 0;
         xfs_log_item_t  *lip;
 
         spin_lock(&ailp->xa_lock);
         lip = xfs_ail_min(ailp);
-        if (lip == NULL) {
-                lsn = (xfs_lsn_t)0;
-        } else {
+        if (lip)
                 lsn = lip->li_lsn;
-        }
         spin_unlock(&ailp->xa_lock);
 
         return lsn;
 }
 
 /*
- * xfs_trans_push_ail
- *
- * This routine is called to move the tail of the AIL forward.  It does this by
- * trying to flush items in the AIL whose lsns are below the given
- * threshold_lsn.
- *
- * the push is run asynchronously in a separate thread, so we return the tail
- * of the log right now instead of the tail after the push. This means we will
- * either continue right away, or we will sleep waiting on the async thread to
- * do its work.
- *
- * We do this unlocked - we only need to know whether there is anything in the
- * AIL at the time we are called. We don't need to access the contents of
- * any of the objects, so the lock is not needed.
+ * Return the maximum lsn held in the AIL, or zero if the AIL is empty.
  */
-void
-xfs_trans_ail_push(
-        struct xfs_ail  *ailp,
-        xfs_lsn_t       threshold_lsn)
+static xfs_lsn_t
+xfs_ail_max_lsn(
+        struct xfs_ail  *ailp)
 {
-        xfs_log_item_t  *lip;
+        xfs_lsn_t       lsn = 0;
+        xfs_log_item_t  *lip;
 
-        lip = xfs_ail_min(ailp);
-        if (lip && !XFS_FORCED_SHUTDOWN(ailp->xa_mount)) {
-                if (XFS_LSN_CMP(threshold_lsn, ailp->xa_target) > 0)
-                        xfsaild_wakeup(ailp, threshold_lsn);
-        }
+        spin_lock(&ailp->xa_lock);
+        lip = xfs_ail_max(ailp);
+        if (lip)
+                lsn = lip->li_lsn;
+        spin_unlock(&ailp->xa_lock);
+
+        return lsn;
 }
 
 /*
@@ -236,16 +300,57 @@ out:
 }
 
 /*
- * xfsaild_push does the work of pushing on the AIL.  Returning a timeout of
- * zero indicates that the caller should sleep until woken.
+ * splice the log item list into the AIL at the given LSN.
  */
-long
-xfsaild_push(
-        struct xfs_ail  *ailp,
-        xfs_lsn_t       *last_lsn)
+static void
+xfs_ail_splice(
+        struct xfs_ail  *ailp,
+        struct list_head *list,
+        xfs_lsn_t       lsn)
 {
-        long            tout = 0;
-        xfs_lsn_t       last_pushed_lsn = *last_lsn;
+        xfs_log_item_t  *next_lip;
+
+        /* If the list is empty, just insert the item.  */
+        if (list_empty(&ailp->xa_ail)) {
+                list_splice(list, &ailp->xa_ail);
+                return;
+        }
+
+        list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) {
+                if (XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0)
+                        break;
+        }
+
+        ASSERT(&next_lip->li_ail == &ailp->xa_ail ||
+               XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0);
+
+        list_splice_init(list, &next_lip->li_ail);
+}
+
+/*
+ * Delete the given item from the AIL.  Return a pointer to the item.
+ */
+static void
+xfs_ail_delete(
+        struct xfs_ail  *ailp,
+        xfs_log_item_t  *lip)
+{
+        xfs_ail_check(ailp, lip);
+        list_del(&lip->li_ail);
+        xfs_trans_ail_cursor_clear(ailp, lip);
+}
+
+/*
+ * xfs_ail_worker does the work of pushing on the AIL. It will requeue itself
+ * to run at a later time if there is more work to do to complete the push.
+ */
+STATIC void
+xfs_ail_worker(
+        struct work_struct *work)
+{
+        struct xfs_ail  *ailp = container_of(to_delayed_work(work),
+                                        struct xfs_ail, xa_work);
+        long            tout;
         xfs_lsn_t       target =  ailp->xa_target;
         xfs_lsn_t       lsn;
         xfs_log_item_t  *lip;
@@ -256,15 +361,15 @@ xfsaild_push(
 
         spin_lock(&ailp->xa_lock);
         xfs_trans_ail_cursor_init(ailp, cur);
-        lip = xfs_trans_ail_cursor_first(ailp, cur, *last_lsn);
+        lip = xfs_trans_ail_cursor_first(ailp, cur, ailp->xa_last_pushed_lsn);
         if (!lip || XFS_FORCED_SHUTDOWN(mp)) {
                 /*
                  * AIL is empty or our push has reached the end.
                  */
                 xfs_trans_ail_cursor_done(ailp, cur);
                 spin_unlock(&ailp->xa_lock);
-                *last_lsn = 0;
-                return tout;
+                ailp->xa_last_pushed_lsn = 0;
+                return;
         }
 
         XFS_STATS_INC(xs_push_ail);
@@ -301,13 +406,13 @@ xfsaild_push(
                 case XFS_ITEM_SUCCESS:
                         XFS_STATS_INC(xs_push_ail_success);
                         IOP_PUSH(lip);
-                        last_pushed_lsn = lsn;
+                        ailp->xa_last_pushed_lsn = lsn;
                         break;
 
                 case XFS_ITEM_PUSHBUF:
                         XFS_STATS_INC(xs_push_ail_pushbuf);
                         IOP_PUSHBUF(lip);
-                        last_pushed_lsn = lsn;
+                        ailp->xa_last_pushed_lsn = lsn;
                         push_xfsbufd = 1;
                         break;
 
@@ -319,7 +424,7 @@ xfsaild_push(
 
                 case XFS_ITEM_LOCKED:
                         XFS_STATS_INC(xs_push_ail_locked);
-                        last_pushed_lsn = lsn;
+                        ailp->xa_last_pushed_lsn = lsn;
                         stuck++;
                         break;
 
@@ -374,9 +479,23 @@ xfsaild_push(
                 wake_up_process(mp->m_ddev_targp->bt_task);
         }
 
+        /* assume we have more work to do in a short while */
+        tout = 10;
         if (!count) {
                 /* We're past our target or empty, so idle */
-                last_pushed_lsn = 0;
+                ailp->xa_last_pushed_lsn = 0;
+
+                /*
+                 * Check for an updated push target before clearing the
+                 * XFS_AIL_PUSHING_BIT. If the target changed, we've got more
+                 * work to do. Wait a bit longer before starting that work.
+                 */
+                smp_rmb();
+                if (ailp->xa_target == target) {
+                        clear_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags);
+                        return;
+                }
+                tout = 50;
         } else if (XFS_LSN_CMP(lsn, target) >= 0) {
                 /*
                  * We reached the target so wait a bit longer for I/O to
@@ -384,7 +503,7 @@ xfsaild_push(
                  * start the next scan from the start of the AIL.
                  */
                 tout = 50;
-                last_pushed_lsn = 0;
+                ailp->xa_last_pushed_lsn = 0;
         } else if ((stuck * 100) / count > 90) {
                 /*
                  * Either there is a lot of contention on the AIL or we
@@ -396,14 +515,61 @@ xfsaild_push(
                  * continuing from where we were.
                  */
                 tout = 20;
-        } else {
-                /* more to do, but wait a short while before continuing */
-                tout = 10;
         }
-        *last_lsn = last_pushed_lsn;
-        return tout;
+
+        /* There is more to do, requeue us.  */
+        queue_delayed_work(xfs_syncd_wq, &ailp->xa_work,
+                                        msecs_to_jiffies(tout));
+}
+
+/*
+ * This routine is called to move the tail of the AIL forward.  It does this by
+ * trying to flush items in the AIL whose lsns are below the given
+ * threshold_lsn.
+ *
+ * The push is run asynchronously in a workqueue, which means the caller needs
+ * to handle waiting on the async flush for space to become available.
+ * We don't want to interrupt any push that is in progress, hence we only queue
+ * work if we set the pushing bit approriately.
+ *
+ * We do this unlocked - we only need to know whether there is anything in the
+ * AIL at the time we are called. We don't need to access the contents of
+ * any of the objects, so the lock is not needed.
+ */
+void
+xfs_ail_push(
+        struct xfs_ail  *ailp,
+        xfs_lsn_t       threshold_lsn)
+{
+        xfs_log_item_t  *lip;
+
+        lip = xfs_ail_min(ailp);
+        if (!lip || XFS_FORCED_SHUTDOWN(ailp->xa_mount) ||
+            XFS_LSN_CMP(threshold_lsn, ailp->xa_target) <= 0)
+                return;
+
+        /*
+         * Ensure that the new target is noticed in push code before it clears
+         * the XFS_AIL_PUSHING_BIT.
+         */
+        smp_wmb();
+        ailp->xa_target = threshold_lsn;
+        if (!test_and_set_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags))
+                queue_delayed_work(xfs_syncd_wq, &ailp->xa_work, 0);
 }
 
+/*
+ * Push out all items in the AIL immediately
+ */
+void
+xfs_ail_push_all(
+        struct xfs_ail  *ailp)
+{
+        xfs_lsn_t       threshold_lsn = xfs_ail_max_lsn(ailp);
+
+        if (threshold_lsn)
+                xfs_ail_push(ailp, threshold_lsn);
+}
 
 /*
  * This is to be called when an item is unlocked that may have
@@ -615,7 +781,6 @@ xfs_trans_ail_init(
         xfs_mount_t     *mp)
 {
         struct xfs_ail  *ailp;
-        int             error;
 
         ailp = kmem_zalloc(sizeof(struct xfs_ail), KM_MAYFAIL);
         if (!ailp)
@@ -624,15 +789,9 @@ xfs_trans_ail_init(
         ailp->xa_mount = mp;
         INIT_LIST_HEAD(&ailp->xa_ail);
         spin_lock_init(&ailp->xa_lock);
-        error = xfsaild_start(ailp);
-        if (error)
-                goto out_free_ailp;
+        INIT_DELAYED_WORK(&ailp->xa_work, xfs_ail_worker);
         mp->m_ail = ailp;
         return 0;
-
-out_free_ailp:
-        kmem_free(ailp);
-        return error;
 }
 
 void
@@ -641,124 +800,6 @@ xfs_trans_ail_destroy(
 {
         struct xfs_ail  *ailp = mp->m_ail;
 
-        xfsaild_stop(ailp);
+        cancel_delayed_work_sync(&ailp->xa_work);
         kmem_free(ailp);
 }
-
-/*
- * splice the log item list into the AIL at the given LSN.
- */
-STATIC void
-xfs_ail_splice(
-        struct xfs_ail  *ailp,
-        struct list_head *list,
-        xfs_lsn_t       lsn)
-{
-        xfs_log_item_t  *next_lip;
-
-        /*
-         * If the list is empty, just insert the item.
-         */
-        if (list_empty(&ailp->xa_ail)) {
-                list_splice(list, &ailp->xa_ail);
-                return;
-        }
-
-        list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) {
-                if (XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0)
-                        break;
-        }
-
-        ASSERT((&next_lip->li_ail == &ailp->xa_ail) ||
-               (XFS_LSN_CMP(next_lip->li_lsn, lsn) <= 0));
-
-        list_splice_init(list, &next_lip->li_ail);
-        return;
-}
-
-/*
- * Delete the given item from the AIL.  Return a pointer to the item.
- */
-STATIC void
-xfs_ail_delete(
-        struct xfs_ail  *ailp,
-        xfs_log_item_t  *lip)
-{
-        xfs_ail_check(ailp, lip);
-        list_del(&lip->li_ail);
-        xfs_trans_ail_cursor_clear(ailp, lip);
-}
-
-/*
- * Return a pointer to the first item in the AIL.
- * If the AIL is empty, then return NULL.
- */
-STATIC xfs_log_item_t *
-xfs_ail_min(
-        struct xfs_ail  *ailp)
-{
-        if (list_empty(&ailp->xa_ail))
-                return NULL;
-
-        return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
-}
-
-/*
- * Return a pointer to the item which follows
- * the given item in the AIL.  If the given item
- * is the last item in the list, then return NULL.
- */
-STATIC xfs_log_item_t *
-xfs_ail_next(
-        struct xfs_ail  *ailp,
-        xfs_log_item_t  *lip)
-{
-        if (lip->li_ail.next == &ailp->xa_ail)
-                return NULL;
-
-        return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail);
-}
-
-#ifdef DEBUG
-/*
- * Check that the list is sorted as it should be.
- */
-STATIC void
-xfs_ail_check(
-        struct xfs_ail  *ailp,
-        xfs_log_item_t  *lip)
-{
-        xfs_log_item_t  *prev_lip;
-
-        if (list_empty(&ailp->xa_ail))
-                return;
-
-        /*
-         * Check the next and previous entries are valid.
-         */
-        ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
-        prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail);
-        if (&prev_lip->li_ail != &ailp->xa_ail)
-                ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
-
-        prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail);
-        if (&prev_lip->li_ail != &ailp->xa_ail)
-                ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0);
-
-
-#ifdef XFS_TRANS_DEBUG
-        /*
-         * Walk the list checking lsn ordering, and that every entry has the
-         * XFS_LI_IN_AIL flag set. This is really expensive, so only do it
-         * when specifically debugging the transaction subsystem.
-         */
-        prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
-        list_for_each_entry(lip, &ailp->xa_ail, li_ail) {
-                if (&prev_lip->li_ail != &ailp->xa_ail)
-                        ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
-                ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
-                prev_lip = lip;
-        }
-#endif /* XFS_TRANS_DEBUG */
-}
-#endif /* DEBUG */
diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h
index 35162c238fa3..6b164e9e9a1f 100644
--- a/fs/xfs/xfs_trans_priv.h
+++ b/fs/xfs/xfs_trans_priv.h
@@ -65,16 +65,22 @@ struct xfs_ail_cursor {
 struct xfs_ail {
         struct xfs_mount        *xa_mount;
         struct list_head        xa_ail;
-        uint                    xa_gen;
-        struct task_struct      *xa_task;
         xfs_lsn_t               xa_target;
         struct xfs_ail_cursor   xa_cursors;
         spinlock_t              xa_lock;
+        struct delayed_work     xa_work;
+        xfs_lsn_t               xa_last_pushed_lsn;
+        unsigned long           xa_flags;
 };
 
+#define XFS_AIL_PUSHING_BIT     0
+
 /*
  * From xfs_trans_ail.c
  */
+
+extern struct workqueue_struct  *xfs_ail_wq;    /* AIL workqueue */
+
 void    xfs_trans_ail_update_bulk(struct xfs_ail *ailp,
                                 struct xfs_log_item **log_items, int nr_items,
                                 xfs_lsn_t lsn) __releases(ailp->xa_lock);
@@ -98,12 +104,13 @@ xfs_trans_ail_delete(
         xfs_trans_ail_delete_bulk(ailp, &lip, 1);
 }
 
-void                    xfs_trans_ail_push(struct xfs_ail *, xfs_lsn_t);
+void                    xfs_ail_push(struct xfs_ail *, xfs_lsn_t);
+void                    xfs_ail_push_all(struct xfs_ail *);
+xfs_lsn_t               xfs_ail_min_lsn(struct xfs_ail *ailp);
+
 void                    xfs_trans_unlocked_item(struct xfs_ail *,
                                         xfs_log_item_t *);
 
-xfs_lsn_t               xfs_trans_ail_tail(struct xfs_ail *ailp);
-
 struct xfs_log_item     *xfs_trans_ail_cursor_first(struct xfs_ail *ailp,
                                         struct xfs_ail_cursor *cur,
                                         xfs_lsn_t lsn);
@@ -112,11 +119,6 @@ struct xfs_log_item	*xfs_trans_ail_cursor_next(struct xfs_ail *ailp,
 void                    xfs_trans_ail_cursor_done(struct xfs_ail *ailp,
                                         struct xfs_ail_cursor *cur);
 
-long    xfsaild_push(struct xfs_ail *, xfs_lsn_t *);
-void    xfsaild_wakeup(struct xfs_ail *, xfs_lsn_t);
-int     xfsaild_start(struct xfs_ail *);
-void    xfsaild_stop(struct xfs_ail *);
-
 #if BITS_PER_LONG != 64
 static inline void
 xfs_trans_ail_copy_lsn(