Merge remote branch 'block/for-next'

Conflicts:
	drivers/block/virtio_blk.c
	drivers/scsi/scsi_error.c

12 files changed, 101 insertions, 48 deletions

diff --git a/fs/bio.c b/fs/bio.c
index e7bf6ca64dcf..8abb2dfb2e7c 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 de7b4d0c7e30..b6e254aefbbb 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 34f7c375567e..64f10082f048 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 8976c3343a96..c03864406af3 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 d6e3af8be95b..dd318ff280b2 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/exofs/ios.c b/fs/exofs/ios.c
index 4337cad7777b..e2732203fa93 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 7608880b5c58..10f939adfa53 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.
@@ -65,6 +74,8 @@ int writeback_in_progress(struct backing_dev_info *bdi)
 static void bdi_queue_work(struct backing_dev_info *bdi,
 		struct wb_writeback_work *work)
 {
+	trace_writeback_queue(bdi, work);
+
 	spin_lock(&bdi->wb_lock);
 	list_add_tail(&work->list, &bdi->work_list);
 	spin_unlock(&bdi->wb_lock);
@@ -73,9 +84,10 @@ static void bdi_queue_work(struct backing_dev_info *bdi,
 	 * 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)))
+	if (unlikely(!bdi->wb.task)) {
+		trace_writeback_nothread(bdi, work);
 		wake_up_process(default_backing_dev_info.wb.task);
-	else {
+	} else {
 		struct bdi_writeback *wb = &bdi->wb;
 
 		if (wb->task)
@@ -95,8 +107,10 @@ __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;
 	}
 
@@ -642,10 +656,14 @@ 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;
 
@@ -673,6 +691,7 @@ 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);
@@ -751,6 +770,8 @@ 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);
 
 		/*
@@ -775,15 +796,43 @@ 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)
 {
+	struct bdi_writeback *wb = data;
+	struct backing_dev_info *bdi = wb->bdi;
 	unsigned long last_active = jiffies;
 	unsigned long wait_jiffies = -1UL;
 	long pages_written;
 
+	/*
+	 * Add us to the active bdi_list
+	 */
+	spin_lock_bh(&bdi_lock);
+	list_add_rcu(&bdi->bdi_list, &bdi_list);
+	spin_unlock_bh(&bdi_lock);
+
+	current->flags |= PF_FLUSHER | PF_SWAPWRITE;
+	set_freezable();
+
+	/*
+	 * Our parent may run at a different priority, just set us to normal
+	 */
+	set_user_nice(current, 0);
+
+	/*
+	 * Clear pending bit and wakeup anybody waiting to tear us down
+	 */
+	clear_bit(BDI_pending, &bdi->state);
+	smp_mb__after_clear_bit();
+	wake_up_bit(&bdi->state, BDI_pending);
+
+	trace_writeback_thread_start(bdi);
+
 	while (!kthread_should_stop()) {
 		pages_written = wb_do_writeback(wb, 0);
 
+		trace_writeback_pages_written(pages_written);
+
 		if (pages_written)
 			last_active = jiffies;
 		else if (wait_jiffies != -1UL) {
@@ -813,9 +862,20 @@ int bdi_writeback_task(struct bdi_writeback *wb)
 		try_to_freeze();
 	}
 
+	wb->task = NULL;
+
+	/*
+	 * Flush any work that raced with us exiting. No new work
+	 * will be added, since this bdi isn't discoverable anymore.
+	 */
+	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.
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 6a857e24f947..cde1248a6225 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 18176d0b75d7..f3b071f921aa 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 45a4a36195d8..99e93f1e50a6 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -275,7 +275,7 @@ 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 2e6a2723b8fa..4588fb9e93df 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 efdbfece9932..ec11c52d646d 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -597,7 +597,6 @@ 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 +620,6 @@ 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;