Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs changes from Chris Mason:
 "This is a pretty long stream of bug fixes and performance fixes.

  Qu Wenruo has replaced the btrfs async threads with regular kernel
  workqueues.  We'll keep an eye out for performance differences, but
  it's nice to be using more generic code for this.

  We still have some corruption fixes and other patches coming in for
  the merge window, but this batch is tested and ready to go"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (108 commits)
  Btrfs: fix a crash of clone with inline extents's split
  btrfs: fix uninit variable warning
  Btrfs: take into account total references when doing backref lookup
  Btrfs: part 2, fix incremental send's decision to delay a dir move/rename
  Btrfs: fix incremental send's decision to delay a dir move/rename
  Btrfs: remove unnecessary inode generation lookup in send
  Btrfs: fix race when updating existing ref head
  btrfs: Add trace for btrfs_workqueue alloc/destroy
  Btrfs: less fs tree lock contention when using autodefrag
  Btrfs: return EPERM when deleting a default subvolume
  Btrfs: add missing kfree in btrfs_destroy_workqueue
  Btrfs: cache extent states in defrag code path
  Btrfs: fix deadlock with nested trans handles
  Btrfs: fix possible empty list access when flushing the delalloc inodes
  Btrfs: split the global ordered extents mutex
  Btrfs: don't flush all delalloc inodes when we doesn't get s_umount lock
  Btrfs: reclaim delalloc metadata more aggressively
  Btrfs: remove unnecessary lock in may_commit_transaction()
  Btrfs: remove the unnecessary flush when preparing the pages
  Btrfs: just do dirty page flush for the inode with compression before direct IO
  ...

1 files changed, 62 insertions, 35 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index efba5d1282ee..93e6d7172844 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -315,6 +315,16 @@ static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
 	atomic_inc(&fs_info->scrubs_running);
 	atomic_inc(&fs_info->scrubs_paused);
 	mutex_unlock(&fs_info->scrub_lock);
+
+	/*
+	 * check if @scrubs_running=@scrubs_paused condition
+	 * inside wait_event() is not an atomic operation.
+	 * which means we may inc/dec @scrub_running/paused
+	 * at any time. Let's wake up @scrub_pause_wait as
+	 * much as we can to let commit transaction blocked less.
+	 */
+	wake_up(&fs_info->scrub_pause_wait);
+
 	atomic_inc(&sctx->workers_pending);
 }
 
@@ -418,7 +428,8 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
 		sbio->index = i;
 		sbio->sctx = sctx;
 		sbio->page_count = 0;
-		sbio->work.func = scrub_bio_end_io_worker;
+		btrfs_init_work(&sbio->work, scrub_bio_end_io_worker,
+				NULL, NULL);
 
 		if (i != SCRUB_BIOS_PER_SCTX - 1)
 			sctx->bios[i]->next_free = i + 1;
@@ -987,9 +998,10 @@ nodatasum_case:
 		fixup_nodatasum->root = fs_info->extent_root;
 		fixup_nodatasum->mirror_num = failed_mirror_index + 1;
 		scrub_pending_trans_workers_inc(sctx);
-		fixup_nodatasum->work.func = scrub_fixup_nodatasum;
-		btrfs_queue_worker(&fs_info->scrub_workers,
-				   &fixup_nodatasum->work);
+		btrfs_init_work(&fixup_nodatasum->work, scrub_fixup_nodatasum,
+				NULL, NULL);
+		btrfs_queue_work(fs_info->scrub_workers,
+				 &fixup_nodatasum->work);
 		goto out;
 	}
 
@@ -1603,8 +1615,8 @@ static void scrub_wr_bio_end_io(struct bio *bio, int err)
 	sbio->err = err;
 	sbio->bio = bio;
 
-	sbio->work.func = scrub_wr_bio_end_io_worker;
-	btrfs_queue_worker(&fs_info->scrub_wr_completion_workers, &sbio->work);
+	btrfs_init_work(&sbio->work, scrub_wr_bio_end_io_worker, NULL, NULL);
+	btrfs_queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
 }
 
 static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
@@ -2072,7 +2084,7 @@ static void scrub_bio_end_io(struct bio *bio, int err)
 	sbio->err = err;
 	sbio->bio = bio;
 
-	btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
+	btrfs_queue_work(fs_info->scrub_workers, &sbio->work);
 }
 
 static void scrub_bio_end_io_worker(struct btrfs_work *work)
@@ -2686,10 +2698,23 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 
 		wait_event(sctx->list_wait,
 			   atomic_read(&sctx->bios_in_flight) == 0);
-		atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
+		atomic_inc(&fs_info->scrubs_paused);
+		wake_up(&fs_info->scrub_pause_wait);
+
+		/*
+		 * must be called before we decrease @scrub_paused.
+		 * make sure we don't block transaction commit while
+		 * we are waiting pending workers finished.
+		 */
 		wait_event(sctx->list_wait,
 			   atomic_read(&sctx->workers_pending) == 0);
-		scrub_blocked_if_needed(fs_info);
+		atomic_set(&sctx->wr_ctx.flush_all_writes, 0);
+
+		mutex_lock(&fs_info->scrub_lock);
+		__scrub_blocked_if_needed(fs_info);
+		atomic_dec(&fs_info->scrubs_paused);
+		mutex_unlock(&fs_info->scrub_lock);
+		wake_up(&fs_info->scrub_pause_wait);
 
 		btrfs_put_block_group(cache);
 		if (ret)
@@ -2757,33 +2782,35 @@ static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
 						int is_dev_replace)
 {
 	int ret = 0;
+	int flags = WQ_FREEZABLE | WQ_UNBOUND;
+	int max_active = fs_info->thread_pool_size;
 
 	if (fs_info->scrub_workers_refcnt == 0) {
 		if (is_dev_replace)
-			btrfs_init_workers(&fs_info->scrub_workers, "scrub", 1,
-					&fs_info->generic_worker);
+			fs_info->scrub_workers =
+				btrfs_alloc_workqueue("btrfs-scrub", flags,
+						      1, 4);
 		else
-			btrfs_init_workers(&fs_info->scrub_workers, "scrub",
-					fs_info->thread_pool_size,
-					&fs_info->generic_worker);
-		fs_info->scrub_workers.idle_thresh = 4;
-		ret = btrfs_start_workers(&fs_info->scrub_workers);
-		if (ret)
+			fs_info->scrub_workers =
+				btrfs_alloc_workqueue("btrfs-scrub", flags,
+						      max_active, 4);
+		if (!fs_info->scrub_workers) {
+			ret = -ENOMEM;
 			goto out;
-		btrfs_init_workers(&fs_info->scrub_wr_completion_workers,
-				   "scrubwrc",
-				   fs_info->thread_pool_size,
-				   &fs_info->generic_worker);
-		fs_info->scrub_wr_completion_workers.idle_thresh = 2;
-		ret = btrfs_start_workers(
-				&fs_info->scrub_wr_completion_workers);
-		if (ret)
+		}
+		fs_info->scrub_wr_completion_workers =
+			btrfs_alloc_workqueue("btrfs-scrubwrc", flags,
+					      max_active, 2);
+		if (!fs_info->scrub_wr_completion_workers) {
+			ret = -ENOMEM;
 			goto out;
-		btrfs_init_workers(&fs_info->scrub_nocow_workers, "scrubnc", 1,
-				   &fs_info->generic_worker);
-		ret = btrfs_start_workers(&fs_info->scrub_nocow_workers);
-		if (ret)
+		}
+		fs_info->scrub_nocow_workers =
+			btrfs_alloc_workqueue("btrfs-scrubnc", flags, 1, 0);
+		if (!fs_info->scrub_nocow_workers) {
+			ret = -ENOMEM;
 			goto out;
+		}
 	}
 	++fs_info->scrub_workers_refcnt;
 out:
@@ -2793,9 +2820,9 @@ out:
 static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
 {
 	if (--fs_info->scrub_workers_refcnt == 0) {
-		btrfs_stop_workers(&fs_info->scrub_workers);
-		btrfs_stop_workers(&fs_info->scrub_wr_completion_workers);
-		btrfs_stop_workers(&fs_info->scrub_nocow_workers);
+		btrfs_destroy_workqueue(fs_info->scrub_workers);
+		btrfs_destroy_workqueue(fs_info->scrub_wr_completion_workers);
+		btrfs_destroy_workqueue(fs_info->scrub_nocow_workers);
 	}
 	WARN_ON(fs_info->scrub_workers_refcnt < 0);
 }
@@ -3106,10 +3133,10 @@ static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
 	nocow_ctx->len = len;
 	nocow_ctx->mirror_num = mirror_num;
 	nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
-	nocow_ctx->work.func = copy_nocow_pages_worker;
+	btrfs_init_work(&nocow_ctx->work, copy_nocow_pages_worker, NULL, NULL);
 	INIT_LIST_HEAD(&nocow_ctx->inodes);
-	btrfs_queue_worker(&fs_info->scrub_nocow_workers,
-			   &nocow_ctx->work);
+	btrfs_queue_work(fs_info->scrub_nocow_workers,
+			 &nocow_ctx->work);
 
 	return 0;
 }