Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits)
  block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n
  xen-blkfront: fix missing out label
  blkdev: fix blkdev_issue_zeroout return value
  block: update request stacking methods to support discards
  block: fix missing export of blk_types.h
  writeback: fix bad _bh spinlock nesting
  drbd: revert "delay probes", feature is being re-implemented differently
  drbd: Initialize all members of sync_conf to their defaults [Bugz 315]
  drbd: Disable delay probes for the upcomming release
  writeback: cleanup bdi_register
  writeback: add new tracepoints
  writeback: remove unnecessary init_timer call
  writeback: optimize periodic bdi thread wakeups
  writeback: prevent unnecessary bdi threads wakeups
  writeback: move bdi threads exiting logic to the forker thread
  writeback: restructure bdi forker loop a little
  writeback: move last_active to bdi
  writeback: do not remove bdi from bdi_list
  writeback: simplify bdi code a little
  writeback: do not lose wake-ups in bdi threads
  ...

Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and
drivers/scsi/scsi_error.c as per Jens.

14 files changed, 147 insertions, 117 deletions

diff --git a/fs/bio.c b/fs/bio.c
index e7bf6ca..8abb2df 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -843,7 +843,8 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
 	if (!bio)
 		goto out_bmd;
 
-	bio->bi_rw |= (!write_to_vm << BIO_RW);
+	if (!write_to_vm)
+		bio->bi_rw |= REQ_WRITE;
 
 	ret = 0;
 
@@ -1024,7 +1025,7 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
 	 * set data direction, and check if mapped pages need bouncing
 	 */
 	if (!write_to_vm)
-		bio->bi_rw |= (1 << BIO_RW);
+		bio->bi_rw |= REQ_WRITE;
 
 	bio->bi_bdev = bdev;
 	bio->bi_flags |= (1 << BIO_USER_MAPPED);
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 451afbd..6641146 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1346,13 +1346,12 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 		return ret;
 	}
 
-	lock_kernel();
  restart:
 
 	ret = -ENXIO;
 	disk = get_gendisk(bdev->bd_dev, &partno);
 	if (!disk)
-		goto out_unlock_kernel;
+		goto out;
 
 	mutex_lock_nested(&bdev->bd_mutex, for_part);
 	if (!bdev->bd_openers) {
@@ -1432,7 +1431,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 	if (for_part)
 		bdev->bd_part_count++;
 	mutex_unlock(&bdev->bd_mutex);
-	unlock_kernel();
 	return 0;
 
  out_clear:
@@ -1445,9 +1443,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 	bdev->bd_contains = NULL;
  out_unlock_bdev:
 	mutex_unlock(&bdev->bd_mutex);
- out_unlock_kernel:
-	unlock_kernel();
-
+ out:
 	if (disk)
 		module_put(disk->fops->owner);
 	put_disk(disk);
@@ -1516,7 +1512,6 @@ static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
 	struct block_device *victim = NULL;
 
 	mutex_lock_nested(&bdev->bd_mutex, for_part);
-	lock_kernel();
 	if (for_part)
 		bdev->bd_part_count--;
 
@@ -1541,7 +1536,6 @@ static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
 			victim = bdev->bd_contains;
 		bdev->bd_contains = NULL;
 	}
-	unlock_kernel();
 	mutex_unlock(&bdev->bd_mutex);
 	bdput(bdev);
 	if (victim)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 34f7c37..64f1008 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -480,7 +480,7 @@ static void end_workqueue_bio(struct bio *bio, int err)
 	end_io_wq->work.func = end_workqueue_fn;
 	end_io_wq->work.flags = 0;
 
-	if (bio->bi_rw & (1 << BIO_RW)) {
+	if (bio->bi_rw & REQ_WRITE) {
 		if (end_io_wq->metadata)
 			btrfs_queue_worker(&fs_info->endio_meta_write_workers,
 					   &end_io_wq->work);
@@ -604,7 +604,7 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 
 	atomic_inc(&fs_info->nr_async_submits);
 
-	if (rw & (1 << BIO_RW_SYNCIO))
+	if (rw & REQ_SYNC)
 		btrfs_set_work_high_prio(&async->work);
 
 	btrfs_queue_worker(&fs_info->workers, &async->work);
@@ -668,7 +668,7 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 					  bio, 1);
 	BUG_ON(ret);
 
-	if (!(rw & (1 << BIO_RW))) {
+	if (!(rw & REQ_WRITE)) {
 		/*
 		 * called for a read, do the setup so that checksum validation
 		 * can happen in the async kernel threads
@@ -1427,7 +1427,7 @@ static void end_workqueue_fn(struct btrfs_work *work)
 	 * ram and up to date before trying to verify things.  For
 	 * blocksize <= pagesize, it is basically a noop
 	 */
-	if (!(bio->bi_rw & (1 << BIO_RW)) && end_io_wq->metadata &&
+	if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
 	    !bio_ready_for_csum(bio)) {
 		btrfs_queue_worker(&fs_info->endio_meta_workers,
 				   &end_io_wq->work);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8976c33..c038644 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1429,7 +1429,7 @@ static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 	ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
 	BUG_ON(ret);
 
-	if (!(rw & (1 << BIO_RW))) {
+	if (!(rw & REQ_WRITE)) {
 		if (bio_flags & EXTENT_BIO_COMPRESSED) {
 			return btrfs_submit_compressed_read(inode, bio,
 						    mirror_num, bio_flags);
@@ -1841,7 +1841,7 @@ static int btrfs_io_failed_hook(struct bio *failed_bio,
 	bio->bi_size = 0;
 
 	bio_add_page(bio, page, failrec->len, start - page_offset(page));
-	if (failed_bio->bi_rw & (1 << BIO_RW))
+	if (failed_bio->bi_rw & REQ_WRITE)
 		rw = WRITE;
 	else
 		rw = READ;
@@ -5647,7 +5647,7 @@ static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
 	struct bio_vec *bvec = bio->bi_io_vec;
 	u64 start;
 	int skip_sum;
-	int write = rw & (1 << BIO_RW);
+	int write = rw & REQ_WRITE;
 	int ret = 0;
 
 	skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d6e3af8..dd318ff 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -258,7 +258,7 @@ loop_lock:
 
 		BUG_ON(atomic_read(&cur->bi_cnt) == 0);
 
-		if (bio_rw_flagged(cur, BIO_RW_SYNCIO))
+		if (cur->bi_rw & REQ_SYNC)
 			num_sync_run++;
 
 		submit_bio(cur->bi_rw, cur);
@@ -2651,7 +2651,7 @@ static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 	int max_errors = 0;
 	struct btrfs_multi_bio *multi = NULL;
 
-	if (multi_ret && !(rw & (1 << BIO_RW)))
+	if (multi_ret && !(rw & REQ_WRITE))
 		stripes_allocated = 1;
 again:
 	if (multi_ret) {
@@ -2687,7 +2687,7 @@ again:
 		mirror_num = 0;
 
 	/* if our multi bio struct is too small, back off and try again */
-	if (rw & (1 << BIO_RW)) {
+	if (rw & REQ_WRITE) {
 		if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
 				 BTRFS_BLOCK_GROUP_DUP)) {
 			stripes_required = map->num_stripes;
@@ -2697,7 +2697,7 @@ again:
 			max_errors = 1;
 		}
 	}
-	if (multi_ret && (rw & (1 << BIO_RW)) &&
+	if (multi_ret && (rw & REQ_WRITE) &&
 	    stripes_allocated < stripes_required) {
 		stripes_allocated = map->num_stripes;
 		free_extent_map(em);
@@ -2733,7 +2733,7 @@ again:
 	num_stripes = 1;
 	stripe_index = 0;
 	if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
-		if (unplug_page || (rw & (1 << BIO_RW)))
+		if (unplug_page || (rw & REQ_WRITE))
 			num_stripes = map->num_stripes;
 		else if (mirror_num)
 			stripe_index = mirror_num - 1;
@@ -2744,7 +2744,7 @@ again:
 		}
 
 	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
-		if (rw & (1 << BIO_RW))
+		if (rw & REQ_WRITE)
 			num_stripes = map->num_stripes;
 		else if (mirror_num)
 			stripe_index = mirror_num - 1;
@@ -2755,7 +2755,7 @@ again:
 		stripe_index = do_div(stripe_nr, factor);
 		stripe_index *= map->sub_stripes;
 
-		if (unplug_page || (rw & (1 << BIO_RW)))
+		if (unplug_page || (rw & REQ_WRITE))
 			num_stripes = map->sub_stripes;
 		else if (mirror_num)
 			stripe_index += mirror_num - 1;
@@ -2945,7 +2945,7 @@ static noinline int schedule_bio(struct btrfs_root *root,
 	struct btrfs_pending_bios *pending_bios;
 
 	/* don't bother with additional async steps for reads, right now */
-	if (!(rw & (1 << BIO_RW))) {
+	if (!(rw & REQ_WRITE)) {
 		bio_get(bio);
 		submit_bio(rw, bio);
 		bio_put(bio);
@@ -2964,7 +2964,7 @@ static noinline int schedule_bio(struct btrfs_root *root,
 	bio->bi_rw |= rw;
 
 	spin_lock(&device->io_lock);
-	if (bio_rw_flagged(bio, BIO_RW_SYNCIO))
+	if (bio->bi_rw & REQ_SYNC)
 		pending_bios = &device->pending_sync_bios;
 	else
 		pending_bios = &device->pending_bios;
diff --git a/fs/coda/psdev.c b/fs/coda/psdev.c
index 66b9cf7..de89645 100644
--- a/fs/coda/psdev.c
+++ b/fs/coda/psdev.c
@@ -177,7 +177,7 @@ static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
 		nbytes = req->uc_outSize; /* don't have more space! */
 	}
         if (copy_from_user(req->uc_data, buf, nbytes)) {
-		req->uc_flags |= REQ_ABORT;
+		req->uc_flags |= CODA_REQ_ABORT;
 		wake_up(&req->uc_sleep);
 		retval = -EFAULT;
 		goto out;
@@ -254,8 +254,8 @@ static ssize_t coda_psdev_read(struct file * file, char __user * buf,
 	        retval = -EFAULT;
         
 	/* If request was not a signal, enqueue and don't free */
-	if (!(req->uc_flags & REQ_ASYNC)) {
-		req->uc_flags |= REQ_READ;
+	if (!(req->uc_flags & CODA_REQ_ASYNC)) {
+		req->uc_flags |= CODA_REQ_READ;
 		list_add_tail(&(req->uc_chain), &vcp->vc_processing);
 		goto out;
 	}
@@ -315,19 +315,19 @@ static int coda_psdev_release(struct inode * inode, struct file * file)
 		list_del(&req->uc_chain);
 
 		/* Async requests need to be freed here */
-		if (req->uc_flags & REQ_ASYNC) {
+		if (req->uc_flags & CODA_REQ_ASYNC) {
 			CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
 			kfree(req);
 			continue;
 		}
-		req->uc_flags |= REQ_ABORT;
+		req->uc_flags |= CODA_REQ_ABORT;
 		wake_up(&req->uc_sleep);
 	}
 
 	list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) {
 		list_del(&req->uc_chain);
 
-		req->uc_flags |= REQ_ABORT;
+		req->uc_flags |= CODA_REQ_ABORT;
 		wake_up(&req->uc_sleep);
 	}
 
diff --git a/fs/coda/upcall.c b/fs/coda/upcall.c
index f09c5ed..b8893ab 100644
--- a/fs/coda/upcall.c
+++ b/fs/coda/upcall.c
@@ -604,7 +604,7 @@ static void coda_unblock_signals(sigset_t *old)
 			       (((r)->uc_opcode != CODA_CLOSE && \
 				 (r)->uc_opcode != CODA_STORE && \
 				 (r)->uc_opcode != CODA_RELEASE) || \
-				(r)->uc_flags & REQ_READ))
+				(r)->uc_flags & CODA_REQ_READ))
 
 static inline void coda_waitfor_upcall(struct upc_req *req)
 {
@@ -624,7 +624,7 @@ static inline void coda_waitfor_upcall(struct upc_req *req)
 			set_current_state(TASK_UNINTERRUPTIBLE);
 
 		/* got a reply */
-		if (req->uc_flags & (REQ_WRITE | REQ_ABORT))
+		if (req->uc_flags & (CODA_REQ_WRITE | CODA_REQ_ABORT))
 			break;
 
 		if (blocked && time_after(jiffies, timeout) &&
@@ -708,7 +708,7 @@ static int coda_upcall(struct venus_comm *vcp,
 	coda_waitfor_upcall(req);
 
 	/* Op went through, interrupt or not... */
-	if (req->uc_flags & REQ_WRITE) {
+	if (req->uc_flags & CODA_REQ_WRITE) {
 		out = (union outputArgs *)req->uc_data;
 		/* here we map positive Venus errors to kernel errors */
 		error = -out->oh.result;
@@ -717,13 +717,13 @@ static int coda_upcall(struct venus_comm *vcp,
 	}
 
 	error = -EINTR;
-	if ((req->uc_flags & REQ_ABORT) || !signal_pending(current)) {
+	if ((req->uc_flags & CODA_REQ_ABORT) || !signal_pending(current)) {
 		printk(KERN_WARNING "coda: Unexpected interruption.\n");
 		goto exit;
 	}
 
 	/* Interrupted before venus read it. */
-	if (!(req->uc_flags & REQ_READ))
+	if (!(req->uc_flags & CODA_REQ_READ))
 		goto exit;
 
 	/* Venus saw the upcall, make sure we can send interrupt signal */
@@ -747,7 +747,7 @@ static int coda_upcall(struct venus_comm *vcp,
 	sig_inputArgs->ih.opcode = CODA_SIGNAL;
 	sig_inputArgs->ih.unique = req->uc_unique;
 
-	sig_req->uc_flags = REQ_ASYNC;
+	sig_req->uc_flags = CODA_REQ_ASYNC;
 	sig_req->uc_opcode = sig_inputArgs->ih.opcode;
 	sig_req->uc_unique = sig_inputArgs->ih.unique;
 	sig_req->uc_inSize = sizeof(struct coda_in_hdr);
diff --git a/fs/exofs/ios.c b/fs/exofs/ios.c
index 4337cad..e273220 100644
--- a/fs/exofs/ios.c
+++ b/fs/exofs/ios.c
@@ -599,7 +599,7 @@ static int _sbi_write_mirror(struct exofs_io_state *ios, int cur_comp)
 			} else {
 				bio = master_dev->bio;
 				/* FIXME: bio_set_dir() */
-				bio->bi_rw |= (1 << BIO_RW);
+				bio->bi_rw |= REQ_WRITE;
 			}
 
 			osd_req_write(or, &ios->obj, per_dev->offset, bio,
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index b7c7586..2f76c4a 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -26,15 +26,9 @@
 #include <linux/blkdev.h>
 #include <linux/backing-dev.h>
 #include <linux/buffer_head.h>
+#include <linux/tracepoint.h>
 #include "internal.h"
 
-#define inode_to_bdi(inode)	((inode)->i_mapping->backing_dev_info)
-
-/*
- * We don't actually have pdflush, but this one is exported though /proc...
- */
-int nr_pdflush_threads;
-
 /*
  * Passed into wb_writeback(), essentially a subset of writeback_control
  */
@@ -50,6 +44,21 @@ struct wb_writeback_work {
 	struct completion *done;	/* set if the caller waits */
 };
 
+/*
+ * Include the creation of the trace points after defining the
+ * wb_writeback_work structure so that the definition remains local to this
+ * file.
+ */
+#define CREATE_TRACE_POINTS
+#include <trace/events/writeback.h>
+
+#define inode_to_bdi(inode)	((inode)->i_mapping->backing_dev_info)
+
+/*
+ * We don't actually have pdflush, but this one is exported though /proc...
+ */
+int nr_pdflush_threads;
+
 /**
  * writeback_in_progress - determine whether there is writeback in progress
  * @bdi: the device's backing_dev_info structure.
@@ -65,22 +74,21 @@ int writeback_in_progress(struct backing_dev_info *bdi)
 static void bdi_queue_work(struct backing_dev_info *bdi,
 		struct wb_writeback_work *work)
 {
-	spin_lock(&bdi->wb_lock);
-	list_add_tail(&work->list, &bdi->work_list);
-	spin_unlock(&bdi->wb_lock);
+	trace_writeback_queue(bdi, work);
 
-	/*
-	 * If the default thread isn't there, make sure we add it. When
-	 * it gets created and wakes up, we'll run this work.
-	 */
-	if (unlikely(list_empty_careful(&bdi->wb_list)))
+	spin_lock_bh(&bdi->wb_lock);
+	list_add_tail(&work->list, &bdi->work_list);
+	if (bdi->wb.task) {
+		wake_up_process(bdi->wb.task);
+	} else {
+		/*
+		 * The bdi thread isn't there, wake up the forker thread which
+		 * will create and run it.
+		 */
+		trace_writeback_nothread(bdi, work);
 		wake_up_process(default_backing_dev_info.wb.task);
-	else {
-		struct bdi_writeback *wb = &bdi->wb;
-
-		if (wb->task)
-			wake_up_process(wb->task);
 	}
+	spin_unlock_bh(&bdi->wb_lock);
 }
 
 static void
@@ -95,8 +103,10 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
 	 */
 	work = kzalloc(sizeof(*work), GFP_ATOMIC);
 	if (!work) {
-		if (bdi->wb.task)
+		if (bdi->wb.task) {
+			trace_writeback_nowork(bdi);
 			wake_up_process(bdi->wb.task);
+		}
 		return;
 	}
 
@@ -643,10 +653,14 @@ static long wb_writeback(struct bdi_writeback *wb,
 		wbc.more_io = 0;
 		wbc.nr_to_write = MAX_WRITEBACK_PAGES;
 		wbc.pages_skipped = 0;
+
+		trace_wbc_writeback_start(&wbc, wb->bdi);
 		if (work->sb)
 			__writeback_inodes_sb(work->sb, wb, &wbc);
 		else
 			writeback_inodes_wb(wb, &wbc);
+		trace_wbc_writeback_written(&wbc, wb->bdi);
+
 		work->nr_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
 		wrote += MAX_WRITEBACK_PAGES - wbc.nr_to_write;
 
@@ -674,6 +688,7 @@ static long wb_writeback(struct bdi_writeback *wb,
 		if (!list_empty(&wb->b_more_io))  {
 			inode = list_entry(wb->b_more_io.prev,
 						struct inode, i_list);
+			trace_wbc_writeback_wait(&wbc, wb->bdi);
 			inode_wait_for_writeback(inode);
 		}
 		spin_unlock(&inode_lock);
@@ -686,17 +701,17 @@ static long wb_writeback(struct bdi_writeback *wb,
  * Return the next wb_writeback_work struct that hasn't been processed yet.
  */
 static struct wb_writeback_work *
-get_next_work_item(struct backing_dev_info *bdi, struct bdi_writeback *wb)
+get_next_work_item(struct backing_dev_info *bdi)
 {
 	struct wb_writeback_work *work = NULL;
 
-	spin_lock(&bdi->wb_lock);
+	spin_lock_bh(&bdi->wb_lock);
 	if (!list_empty(&bdi->work_list)) {
 		work = list_entry(bdi->work_list.next,
 				  struct wb_writeback_work, list);
 		list_del_init(&work->list);
 	}
-	spin_unlock(&bdi->wb_lock);
+	spin_unlock_bh(&bdi->wb_lock);
 	return work;
 }
 
@@ -744,7 +759,7 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
 	struct wb_writeback_work *work;
 	long wrote = 0;
 
-	while ((work = get_next_work_item(bdi, wb)) != NULL) {
+	while ((work = get_next_work_item(bdi)) != NULL) {
 		/*
 		 * Override sync mode, in case we must wait for completion
 		 * because this thread is exiting now.
@@ -752,6 +767,8 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
 		if (force_wait)
 			work->sync_mode = WB_SYNC_ALL;
 
+		trace_writeback_exec(bdi, work);
+
 		wrote += wb_writeback(wb, work);
 
 		/*
@@ -776,47 +793,66 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
  * Handle writeback of dirty data for the device backed by this bdi. Also
  * wakes up periodically and does kupdated style flushing.
  */
-int bdi_writeback_task(struct bdi_writeback *wb)
+int bdi_writeback_thread(void *data)
 {
-	unsigned long last_active = jiffies;
-	unsigned long wait_jiffies = -1UL;
+	struct bdi_writeback *wb = data;
+	struct backing_dev_info *bdi = wb->bdi;
 	long pages_written;
 
+	current->flags |= PF_FLUSHER | PF_SWAPWRITE;
+	set_freezable();
+	wb->last_active = jiffies;
+
+	/*
+	 * Our parent may run at a different priority, just set us to normal
+	 */
+	set_user_nice(current, 0);
+
+	trace_writeback_thread_start(bdi);
+
 	while (!kthread_should_stop()) {
+		/*
+		 * Remove own delayed wake-up timer, since we are already awake
+		 * and we'll take care of the preriodic write-back.
+		 */
+		del_timer(&wb->wakeup_timer);
+
 		pages_written = wb_do_writeback(wb, 0);
 
+		trace_writeback_pages_written(pages_written);
+
 		if (pages_written)
-			last_active = jiffies;
-		else if (wait_jiffies != -1UL) {
-			unsigned long max_idle;
+			wb->last_active = jiffies;
 
-			/*
-			 * Longest period of inactivity that we tolerate. If we
-			 * see dirty data again later, the task will get
-			 * recreated automatically.
-			 */
-			max_idle = max(5UL * 60 * HZ, wait_jiffies);
-			if (time_after(jiffies, max_idle + last_active))
-				break;
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (!list_empty(&bdi->work_list)) {
+			__set_current_state(TASK_RUNNING);
+			continue;
 		}
 
-		if (dirty_writeback_interval) {
-			wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
-			schedule_timeout_interruptible(wait_jiffies);
-		} else {
-			set_current_state(TASK_INTERRUPTIBLE);
-			if (list_empty_careful(&wb->bdi->work_list) &&
-			    !kthread_should_stop())
-				schedule();
-			__set_current_state(TASK_RUNNING);
+		if (wb_has_dirty_io(wb) && dirty_writeback_interval)
+			schedule_timeout(msecs_to_jiffies(dirty_writeback_interval * 10));
+		else {
+			/*
+			 * We have nothing to do, so can go sleep without any
+			 * timeout and save power. When a work is queued or
+			 * something is made dirty - we will be woken up.
+			 */
+			schedule();
 		}
 
 		try_to_freeze();
 	}
 
+	/* Flush any work that raced with us exiting */
+	if (!list_empty(&bdi->work_list))
+		wb_do_writeback(wb, 1);
+
+	trace_writeback_thread_stop(bdi);
 	return 0;
 }
 
+
 /*
  * Start writeback of `nr_pages' pages.  If `nr_pages' is zero, write back
  * the whole world.
@@ -891,6 +927,8 @@ static noinline void block_dump___mark_inode_dirty(struct inode *inode)
 void __mark_inode_dirty(struct inode *inode, int flags)
 {
 	struct super_block *sb = inode->i_sb;
+	struct backing_dev_info *bdi = NULL;
+	bool wakeup_bdi = false;
 
 	/*
 	 * Don't do this for I_DIRTY_PAGES - that doesn't actually
@@ -944,22 +982,31 @@ void __mark_inode_dirty(struct inode *inode, int flags)
 		 * reposition it (that would break b_dirty time-ordering).
 		 */
 		if (!was_dirty) {
-			struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
-			struct backing_dev_info *bdi = wb->bdi;
-
-			if (bdi_cap_writeback_dirty(bdi) &&
-			    !test_bit(BDI_registered, &bdi->state)) {
-				WARN_ON(1);
-				printk(KERN_ERR "bdi-%s not registered\n",
-								bdi->name);
+			bdi = inode_to_bdi(inode);
+
+			if (bdi_cap_writeback_dirty(bdi)) {
+				WARN(!test_bit(BDI_registered, &bdi->state),
+				     "bdi-%s not registered\n", bdi->name);
+
+				/*
+				 * If this is the first dirty inode for this
+				 * bdi, we have to wake-up the corresponding
+				 * bdi thread to make sure background
+				 * write-back happens later.
+				 */
+				if (!wb_has_dirty_io(&bdi->wb))
+					wakeup_bdi = true;
 			}
 
 			inode->dirtied_when = jiffies;
-			list_move(&inode->i_list, &wb->b_dirty);
+			list_move(&inode->i_list, &bdi->wb.b_dirty);
 		}
 	}
 out:
 	spin_unlock(&inode_lock);
+
+	if (wakeup_bdi)
+		bdi_wakeup_thread_delayed(bdi);
 }
 EXPORT_SYMBOL(__mark_inode_dirty);
 
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 6a857e24..cde1248 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -595,7 +595,7 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 	if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
 		goto skip_barrier;
 	get_bh(bh);
-	submit_bh(WRITE_SYNC | (1 << BIO_RW_BARRIER) | (1 << BIO_RW_META), bh);
+	submit_bh(WRITE_BARRIER | REQ_META, bh);
 	wait_on_buffer(bh);
 	if (buffer_eopnotsupp(bh)) {
 		clear_buffer_eopnotsupp(bh);
@@ -605,7 +605,7 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
 		lock_buffer(bh);
 skip_barrier:
 		get_bh(bh);
-		submit_bh(WRITE_SYNC | (1 << BIO_RW_META), bh);
+		submit_bh(WRITE_SYNC | REQ_META, bh);
 		wait_on_buffer(bh);
 	}
 	if (!buffer_uptodate(bh))
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 18176d0..f3b071f 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -36,8 +36,8 @@ static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wb
 {
 	struct buffer_head *bh, *head;
 	int nr_underway = 0;
-	int write_op = (1 << BIO_RW_META) | ((wbc->sync_mode == WB_SYNC_ALL ?
-			WRITE_SYNC_PLUG : WRITE));
+	int write_op = REQ_META |
+		(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC_PLUG : WRITE);
 
 	BUG_ON(!PageLocked(page));
 	BUG_ON(!page_has_buffers(page));
@@ -225,7 +225,7 @@ int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
 	}
 	bh->b_end_io = end_buffer_read_sync;
 	get_bh(bh);
-	submit_bh(READ_SYNC | (1 << BIO_RW_META), bh);
+	submit_bh(READ_SYNC | REQ_META, bh);
 	if (!(flags & DIO_WAIT))
 		return 0;
 
@@ -432,7 +432,7 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
 	if (buffer_uptodate(first_bh))
 		goto out;
 	if (!buffer_locked(first_bh))
-		ll_rw_block(READ_SYNC | (1 << BIO_RW_META), 1, &first_bh);
+		ll_rw_block(READ_SYNC | REQ_META, 1, &first_bh);
 
 	dblock++;
 	extlen--;
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 4f44bde..4d4b1e8 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -274,7 +274,7 @@ static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector)
 
 	bio->bi_end_io = end_bio_io_page;
 	bio->bi_private = page;
-	submit_bio(READ_SYNC | (1 << BIO_RW_META), bio);
+	submit_bio(READ_SYNC | REQ_META, bio);
 	wait_on_page_locked(page);
 	bio_put(bio);
 	if (!PageUptodate(page)) {
diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c
index 2e6a272..4588fb9 100644
--- a/fs/nilfs2/segbuf.c
+++ b/fs/nilfs2/segbuf.c
@@ -508,7 +508,7 @@ static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
 		 * Last BIO is always sent through the following
 		 * submission.
 		 */
-		rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
+		rw |= REQ_SYNC | REQ_UNPLUG;
 		res = nilfs_segbuf_submit_bio(segbuf, &wi, rw);
 	}
 
diff --git a/fs/splice.c b/fs/splice.c
index efdbfec..8f1dfae 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -399,17 +399,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 		 * If the page isn't uptodate, we may need to start io on it
 		 */
 		if (!PageUptodate(page)) {
-			/*
-			 * If in nonblock mode then dont block on waiting
-			 * for an in-flight io page
-			 */
-			if (flags & SPLICE_F_NONBLOCK) {
-				if (!trylock_page(page)) {
-					error = -EAGAIN;
-					break;
-				}
-			} else
-				lock_page(page);
+			lock_page(page);
 
 			/*
 			 * Page was truncated, or invalidated by the
@@ -597,7 +587,6 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 	struct page *pages[PIPE_DEF_BUFFERS];
 	struct partial_page partial[PIPE_DEF_BUFFERS];
 	struct iovec *vec, __vec[PIPE_DEF_BUFFERS];
-	pgoff_t index;
 	ssize_t res;
 	size_t this_len;
 	int error;
@@ -621,7 +610,6 @@ ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
 			goto shrink_ret;
 	}
 
-	index = *ppos >> PAGE_CACHE_SHIFT;
 	offset = *ppos & ~PAGE_CACHE_MASK;
 	nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;