1 files changed, 247 insertions, 172 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index dd52146035b..08e65e9cf2a 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -49,6 +49,7 @@
 #include "dev-replace.h"
 #include "raid56.h"
 #include "sysfs.h"
+#include "qgroup.h"
 
 #ifdef CONFIG_X86
 #include <asm/cpufeature.h>
@@ -329,6 +330,8 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
 {
 	struct extent_state *cached_state = NULL;
 	int ret;
+	bool need_lock = (current->journal_info ==
+			  (void *)BTRFS_SEND_TRANS_STUB);
 
 	if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
 		return 0;
@@ -336,6 +339,11 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
 	if (atomic)
 		return -EAGAIN;
 
+	if (need_lock) {
+		btrfs_tree_read_lock(eb);
+		btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+	}
+
 	lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
 			 0, &cached_state);
 	if (extent_buffer_uptodate(eb) &&
@@ -347,10 +355,22 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
 		       "found %llu\n",
 		       eb->start, parent_transid, btrfs_header_generation(eb));
 	ret = 1;
-	clear_extent_buffer_uptodate(eb);
+
+	/*
+	 * Things reading via commit roots that don't have normal protection,
+	 * like send, can have a really old block in cache that may point at a
+	 * block that has been free'd and re-allocated.  So don't clear uptodate
+	 * if we find an eb that is under IO (dirty/writeback) because we could
+	 * end up reading in the stale data and then writing it back out and
+	 * making everybody very sad.
+	 */
+	if (!extent_buffer_under_io(eb))
+		clear_extent_buffer_uptodate(eb);
 out:
 	unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
 			     &cached_state, GFP_NOFS);
+	if (need_lock)
+		btrfs_tree_read_unlock_blocking(eb);
 	return ret;
 }
 
@@ -678,32 +698,31 @@ static void end_workqueue_bio(struct bio *bio, int err)
 
 	fs_info = end_io_wq->info;
 	end_io_wq->error = err;
-	end_io_wq->work.func = end_workqueue_fn;
-	end_io_wq->work.flags = 0;
+	btrfs_init_work(&end_io_wq->work, end_workqueue_fn, NULL, NULL);
 
 	if (bio->bi_rw & REQ_WRITE) {
 		if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA)
-			btrfs_queue_worker(&fs_info->endio_meta_write_workers,
-					   &end_io_wq->work);
+			btrfs_queue_work(fs_info->endio_meta_write_workers,
+					 &end_io_wq->work);
 		else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE)
-			btrfs_queue_worker(&fs_info->endio_freespace_worker,
-					   &end_io_wq->work);
+			btrfs_queue_work(fs_info->endio_freespace_worker,
+					 &end_io_wq->work);
 		else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56)
-			btrfs_queue_worker(&fs_info->endio_raid56_workers,
-					   &end_io_wq->work);
+			btrfs_queue_work(fs_info->endio_raid56_workers,
+					 &end_io_wq->work);
 		else
-			btrfs_queue_worker(&fs_info->endio_write_workers,
-					   &end_io_wq->work);
+			btrfs_queue_work(fs_info->endio_write_workers,
+					 &end_io_wq->work);
 	} else {
 		if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56)
-			btrfs_queue_worker(&fs_info->endio_raid56_workers,
-					   &end_io_wq->work);
+			btrfs_queue_work(fs_info->endio_raid56_workers,
+					 &end_io_wq->work);
 		else if (end_io_wq->metadata)
-			btrfs_queue_worker(&fs_info->endio_meta_workers,
-					   &end_io_wq->work);
+			btrfs_queue_work(fs_info->endio_meta_workers,
+					 &end_io_wq->work);
 		else
-			btrfs_queue_worker(&fs_info->endio_workers,
-					   &end_io_wq->work);
+			btrfs_queue_work(fs_info->endio_workers,
+					 &end_io_wq->work);
 	}
 }
 
@@ -738,7 +757,7 @@ int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
 {
 	unsigned long limit = min_t(unsigned long,
-				    info->workers.max_workers,
+				    info->thread_pool_size,
 				    info->fs_devices->open_devices);
 	return 256 * limit;
 }
@@ -811,11 +830,9 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 	async->submit_bio_start = submit_bio_start;
 	async->submit_bio_done = submit_bio_done;
 
-	async->work.func = run_one_async_start;
-	async->work.ordered_func = run_one_async_done;
-	async->work.ordered_free = run_one_async_free;
+	btrfs_init_work(&async->work, run_one_async_start,
+			run_one_async_done, run_one_async_free);
 
-	async->work.flags = 0;
 	async->bio_flags = bio_flags;
 	async->bio_offset = bio_offset;
 
@@ -824,9 +841,9 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 	atomic_inc(&fs_info->nr_async_submits);
 
 	if (rw & REQ_SYNC)
-		btrfs_set_work_high_prio(&async->work);
+		btrfs_set_work_high_priority(&async->work);
 
-	btrfs_queue_worker(&fs_info->workers, &async->work);
+	btrfs_queue_work(fs_info->workers, &async->work);
 
 	while (atomic_read(&fs_info->async_submit_draining) &&
 	      atomic_read(&fs_info->nr_async_submits)) {
@@ -839,20 +856,17 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 
 static int btree_csum_one_bio(struct bio *bio)
 {
-	struct bio_vec *bvec = bio->bi_io_vec;
-	int bio_index = 0;
+	struct bio_vec *bvec;
 	struct btrfs_root *root;
-	int ret = 0;
+	int i, ret = 0;
 
-	WARN_ON(bio->bi_vcnt <= 0);
-	while (bio_index < bio->bi_vcnt) {
+	bio_for_each_segment_all(bvec, bio, i) {
 		root = BTRFS_I(bvec->bv_page->mapping->host)->root;
 		ret = csum_dirty_buffer(root, bvec->bv_page);
 		if (ret)
 			break;
-		bio_index++;
-		bvec++;
 	}
+
 	return ret;
 }
 
@@ -1097,6 +1111,11 @@ struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 						 u64 bytenr, u32 blocksize)
 {
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+	if (unlikely(test_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state)))
+		return alloc_test_extent_buffer(root->fs_info, bytenr,
+						blocksize);
+#endif
 	return alloc_extent_buffer(root->fs_info, bytenr, blocksize);
 }
 
@@ -1152,6 +1171,32 @@ void clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	}
 }
 
+static struct btrfs_subvolume_writers *btrfs_alloc_subvolume_writers(void)
+{
+	struct btrfs_subvolume_writers *writers;
+	int ret;
+
+	writers = kmalloc(sizeof(*writers), GFP_NOFS);
+	if (!writers)
+		return ERR_PTR(-ENOMEM);
+
+	ret = percpu_counter_init(&writers->counter, 0);
+	if (ret < 0) {
+		kfree(writers);
+		return ERR_PTR(ret);
+	}
+
+	init_waitqueue_head(&writers->wait);
+	return writers;
+}
+
+static void
+btrfs_free_subvolume_writers(struct btrfs_subvolume_writers *writers)
+{
+	percpu_counter_destroy(&writers->counter);
+	kfree(writers);
+}
+
 static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 			 u32 stripesize, struct btrfs_root *root,
 			 struct btrfs_fs_info *fs_info,
@@ -1163,10 +1208,7 @@ static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 	root->nodesize = nodesize;
 	root->leafsize = leafsize;
 	root->stripesize = stripesize;
-	root->ref_cows = 0;
-	root->track_dirty = 0;
-	root->in_radix = 0;
-	root->orphan_item_inserted = 0;
+	root->state = 0;
 	root->orphan_cleanup_state = 0;
 
 	root->objectid = objectid;
@@ -1197,6 +1239,8 @@ static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 	spin_lock_init(&root->log_extents_lock[1]);
 	mutex_init(&root->objectid_mutex);
 	mutex_init(&root->log_mutex);
+	mutex_init(&root->ordered_extent_mutex);
+	mutex_init(&root->delalloc_mutex);
 	init_waitqueue_head(&root->log_writer_wait);
 	init_waitqueue_head(&root->log_commit_wait[0]);
 	init_waitqueue_head(&root->log_commit_wait[1]);
@@ -1208,6 +1252,7 @@ static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 	atomic_set(&root->log_batch, 0);
 	atomic_set(&root->orphan_inodes, 0);
 	atomic_set(&root->refs, 1);
+	atomic_set(&root->will_be_snapshoted, 0);
 	root->log_transid = 0;
 	root->log_transid_committed = -1;
 	root->last_log_commit = 0;
@@ -1224,7 +1269,6 @@ static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 	else
 		root->defrag_trans_start = 0;
 	init_completion(&root->kobj_unregister);
-	root->defrag_running = 0;
 	root->root_key.objectid = objectid;
 	root->anon_dev = 0;
 
@@ -1249,7 +1293,8 @@ struct btrfs_root *btrfs_alloc_dummy_root(void)
 	if (!root)
 		return ERR_PTR(-ENOMEM);
 	__setup_root(4096, 4096, 4096, 4096, root, NULL, 1);
-	root->dummy_root = 1;
+	set_bit(BTRFS_ROOT_DUMMY_ROOT, &root->state);
+	root->alloc_bytenr = 0;
 
 	return root;
 }
@@ -1300,8 +1345,7 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 	btrfs_mark_buffer_dirty(leaf);
 
 	root->commit_root = btrfs_root_node(root);
-	root->track_dirty = 1;
-
+	set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
 
 	root->root_item.flags = 0;
 	root->root_item.byte_limit = 0;
@@ -1330,6 +1374,7 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 fail:
 	if (leaf) {
 		btrfs_tree_unlock(leaf);
+		free_extent_buffer(root->commit_root);
 		free_extent_buffer(leaf);
 	}
 	kfree(root);
@@ -1355,13 +1400,15 @@ static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
 	root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
 	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
 	root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
+
 	/*
+	 * DON'T set REF_COWS for log trees
+	 *
 	 * log trees do not get reference counted because they go away
 	 * before a real commit is actually done.  They do store pointers
 	 * to file data extents, and those reference counts still get
 	 * updated (along with back refs to the log tree).
 	 */
-	root->ref_cows = 0;
 
 	leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
 				      BTRFS_TREE_LOG_OBJECTID, NULL,
@@ -1495,7 +1542,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
 		return root;
 
 	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
-		root->ref_cows = 1;
+		set_bit(BTRFS_ROOT_REF_COWS, &root->state);
 		btrfs_check_and_init_root_item(&root->root_item);
 	}
 
@@ -1505,6 +1552,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
 int btrfs_init_fs_root(struct btrfs_root *root)
 {
 	int ret;
+	struct btrfs_subvolume_writers *writers;
 
 	root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
 	root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
@@ -1514,15 +1562,24 @@ int btrfs_init_fs_root(struct btrfs_root *root)
 		goto fail;
 	}
 
+	writers = btrfs_alloc_subvolume_writers();
+	if (IS_ERR(writers)) {
+		ret = PTR_ERR(writers);
+		goto fail;
+	}
+	root->subv_writers = writers;
+
 	btrfs_init_free_ino_ctl(root);
-	mutex_init(&root->fs_commit_mutex);
 	spin_lock_init(&root->cache_lock);
 	init_waitqueue_head(&root->cache_wait);
 
 	ret = get_anon_bdev(&root->anon_dev);
 	if (ret)
-		goto fail;
+		goto free_writers;
 	return 0;
+
+free_writers:
+	btrfs_free_subvolume_writers(root->subv_writers);
 fail:
 	kfree(root->free_ino_ctl);
 	kfree(root->free_ino_pinned);
@@ -1555,7 +1612,7 @@ int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
 				(unsigned long)root->root_key.objectid,
 				root);
 	if (ret == 0)
-		root->in_radix = 1;
+		set_bit(BTRFS_ROOT_IN_RADIX, &root->state);
 	spin_unlock(&fs_info->fs_roots_radix_lock);
 	radix_tree_preload_end();
 
@@ -1611,7 +1668,7 @@ again:
 	if (ret < 0)
 		goto fail;
 	if (ret == 0)
-		root->orphan_item_inserted = 1;
+		set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
 
 	ret = btrfs_insert_fs_root(fs_info, root);
 	if (ret) {
@@ -1684,7 +1741,7 @@ static void end_workqueue_fn(struct btrfs_work *work)
 	bio->bi_private = end_io_wq->private;
 	bio->bi_end_io = end_io_wq->end_io;
 	kfree(end_io_wq);
-	bio_endio(bio, error);
+	bio_endio_nodec(bio, error);
 }
 
 static int cleaner_kthread(void *arg)
@@ -1997,23 +2054,23 @@ static noinline int next_root_backup(struct btrfs_fs_info *info,
 /* helper to cleanup workers */
 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
 {
-	btrfs_stop_workers(&fs_info->generic_worker);
-	btrfs_stop_workers(&fs_info->fixup_workers);
-	btrfs_stop_workers(&fs_info->delalloc_workers);
-	btrfs_stop_workers(&fs_info->workers);
-	btrfs_stop_workers(&fs_info->endio_workers);
-	btrfs_stop_workers(&fs_info->endio_meta_workers);
-	btrfs_stop_workers(&fs_info->endio_raid56_workers);
-	btrfs_stop_workers(&fs_info->rmw_workers);
-	btrfs_stop_workers(&fs_info->endio_meta_write_workers);
-	btrfs_stop_workers(&fs_info->endio_write_workers);
-	btrfs_stop_workers(&fs_info->endio_freespace_worker);
-	btrfs_stop_workers(&fs_info->submit_workers);
-	btrfs_stop_workers(&fs_info->delayed_workers);
-	btrfs_stop_workers(&fs_info->caching_workers);
-	btrfs_stop_workers(&fs_info->readahead_workers);
-	btrfs_stop_workers(&fs_info->flush_workers);
-	btrfs_stop_workers(&fs_info->qgroup_rescan_workers);
+	btrfs_destroy_workqueue(fs_info->fixup_workers);
+	btrfs_destroy_workqueue(fs_info->delalloc_workers);
+	btrfs_destroy_workqueue(fs_info->workers);
+	btrfs_destroy_workqueue(fs_info->endio_workers);
+	btrfs_destroy_workqueue(fs_info->endio_meta_workers);
+	btrfs_destroy_workqueue(fs_info->endio_raid56_workers);
+	btrfs_destroy_workqueue(fs_info->rmw_workers);
+	btrfs_destroy_workqueue(fs_info->endio_meta_write_workers);
+	btrfs_destroy_workqueue(fs_info->endio_write_workers);
+	btrfs_destroy_workqueue(fs_info->endio_freespace_worker);
+	btrfs_destroy_workqueue(fs_info->submit_workers);
+	btrfs_destroy_workqueue(fs_info->delayed_workers);
+	btrfs_destroy_workqueue(fs_info->caching_workers);
+	btrfs_destroy_workqueue(fs_info->readahead_workers);
+	btrfs_destroy_workqueue(fs_info->flush_workers);
+	btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
+	btrfs_destroy_workqueue(fs_info->extent_workers);
 }
 
 static void free_root_extent_buffers(struct btrfs_root *root)
@@ -2040,7 +2097,7 @@ static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
 		free_root_extent_buffers(info->chunk_root);
 }
 
-static void del_fs_roots(struct btrfs_fs_info *fs_info)
+void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
 {
 	int ret;
 	struct btrfs_root *gang[8];
@@ -2051,7 +2108,7 @@ static void del_fs_roots(struct btrfs_fs_info *fs_info)
 				     struct btrfs_root, root_list);
 		list_del(&gang[0]->root_list);
 
-		if (gang[0]->in_radix) {
+		if (test_bit(BTRFS_ROOT_IN_RADIX, &gang[0]->state)) {
 			btrfs_drop_and_free_fs_root(fs_info, gang[0]);
 		} else {
 			free_extent_buffer(gang[0]->node);
@@ -2104,6 +2161,8 @@ int open_ctree(struct super_block *sb,
 	int err = -EINVAL;
 	int num_backups_tried = 0;
 	int backup_index = 0;
+	int max_active;
+	int flags = WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_UNBOUND;
 	bool create_uuid_tree;
 	bool check_uuid_tree;
 
@@ -2169,9 +2228,11 @@ int open_ctree(struct super_block *sb,
 	spin_lock_init(&fs_info->free_chunk_lock);
 	spin_lock_init(&fs_info->tree_mod_seq_lock);
 	spin_lock_init(&fs_info->super_lock);
+	spin_lock_init(&fs_info->qgroup_op_lock);
 	spin_lock_init(&fs_info->buffer_lock);
 	rwlock_init(&fs_info->tree_mod_log_lock);
 	mutex_init(&fs_info->reloc_mutex);
+	mutex_init(&fs_info->delalloc_root_mutex);
 	seqlock_init(&fs_info->profiles_lock);
 
 	init_completion(&fs_info->kobj_unregister);
@@ -2193,6 +2254,7 @@ int open_ctree(struct super_block *sb,
 	atomic_set(&fs_info->async_submit_draining, 0);
 	atomic_set(&fs_info->nr_async_bios, 0);
 	atomic_set(&fs_info->defrag_running, 0);
+	atomic_set(&fs_info->qgroup_op_seq, 0);
 	atomic64_set(&fs_info->tree_mod_seq, 0);
 	fs_info->sb = sb;
 	fs_info->max_inline = 8192 * 1024;
@@ -2238,6 +2300,7 @@ int open_ctree(struct super_block *sb,
 	atomic_set(&fs_info->balance_cancel_req, 0);
 	fs_info->balance_ctl = NULL;
 	init_waitqueue_head(&fs_info->balance_wait_q);
+	btrfs_init_async_reclaim_work(&fs_info->async_reclaim_work);
 
 	sb->s_blocksize = 4096;
 	sb->s_blocksize_bits = blksize_bits(4096);
@@ -2288,7 +2351,7 @@ int open_ctree(struct super_block *sb,
 	mutex_init(&fs_info->transaction_kthread_mutex);
 	mutex_init(&fs_info->cleaner_mutex);
 	mutex_init(&fs_info->volume_mutex);
-	init_rwsem(&fs_info->extent_commit_sem);
+	init_rwsem(&fs_info->commit_root_sem);
 	init_rwsem(&fs_info->cleanup_work_sem);
 	init_rwsem(&fs_info->subvol_sem);
 	sema_init(&fs_info->uuid_tree_rescan_sem, 1);
@@ -2301,6 +2364,7 @@ int open_ctree(struct super_block *sb,
 	spin_lock_init(&fs_info->qgroup_lock);
 	mutex_init(&fs_info->qgroup_ioctl_lock);
 	fs_info->qgroup_tree = RB_ROOT;
+	fs_info->qgroup_op_tree = RB_ROOT;
 	INIT_LIST_HEAD(&fs_info->dirty_qgroups);
 	fs_info->qgroup_seq = 1;
 	fs_info->quota_enabled = 0;
@@ -2472,104 +2536,73 @@ int open_ctree(struct super_block *sb,
 		goto fail_alloc;
 	}
 
-	btrfs_init_workers(&fs_info->generic_worker,
-			   "genwork", 1, NULL);
+	max_active = fs_info->thread_pool_size;
 
-	btrfs_init_workers(&fs_info->workers, "worker",
-			   fs_info->thread_pool_size,
-			   &fs_info->generic_worker);
+	fs_info->workers =
+		btrfs_alloc_workqueue("worker", flags | WQ_HIGHPRI,
+				      max_active, 16);
 
-	btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
-			   fs_info->thread_pool_size, NULL);
+	fs_info->delalloc_workers =
+		btrfs_alloc_workqueue("delalloc", flags, max_active, 2);
 
-	btrfs_init_workers(&fs_info->flush_workers, "flush_delalloc",
-			   fs_info->thread_pool_size, NULL);
+	fs_info->flush_workers =
+		btrfs_alloc_workqueue("flush_delalloc", flags, max_active, 0);
 
-	btrfs_init_workers(&fs_info->submit_workers, "submit",
-			   min_t(u64, fs_devices->num_devices,
-			   fs_info->thread_pool_size), NULL);
+	fs_info->caching_workers =
+		btrfs_alloc_workqueue("cache", flags, max_active, 0);
 
-	btrfs_init_workers(&fs_info->caching_workers, "cache",
-			   fs_info->thread_pool_size, NULL);
-
-	/* a higher idle thresh on the submit workers makes it much more
+	/*
+	 * a higher idle thresh on the submit workers makes it much more
 	 * likely that bios will be send down in a sane order to the
 	 * devices
 	 */
-	fs_info->submit_workers.idle_thresh = 64;
-
-	fs_info->workers.idle_thresh = 16;
-	fs_info->workers.ordered = 1;
-
-	fs_info->delalloc_workers.idle_thresh = 2;
-	fs_info->delalloc_workers.ordered = 1;
-
-	btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
-			   &fs_info->generic_worker);
-	btrfs_init_workers(&fs_info->endio_workers, "endio",
-			   fs_info->thread_pool_size,
-			   &fs_info->generic_worker);
-	btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
-			   fs_info->thread_pool_size,
-			   &fs_info->generic_worker);
-	btrfs_init_workers(&fs_info->endio_meta_write_workers,
-			   "endio-meta-write", fs_info->thread_pool_size,
-			   &fs_info->generic_worker);
-	btrfs_init_workers(&fs_info->endio_raid56_workers,
-			   "endio-raid56", fs_info->thread_pool_size,
-			   &fs_info->generic_worker);
-	btrfs_init_workers(&fs_info->rmw_workers,
-			   "rmw", fs_info->thread_pool_size,
-			   &fs_info->generic_worker);
-	btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
-			   fs_info->thread_pool_size,
-			   &fs_info->generic_worker);
-	btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
-			   1, &fs_info->generic_worker);
-	btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
-			   fs_info->thread_pool_size,
-			   &fs_info->generic_worker);
-	btrfs_init_workers(&fs_info->readahead_workers, "readahead",
-			   fs_info->thread_pool_size,
-			   &fs_info->generic_worker);
-	btrfs_init_workers(&fs_info->qgroup_rescan_workers, "qgroup-rescan", 1,
-			   &fs_info->generic_worker);
+	fs_info->submit_workers =
+		btrfs_alloc_workqueue("submit", flags,
+				      min_t(u64, fs_devices->num_devices,
+					    max_active), 64);
+
+	fs_info->fixup_workers =
+		btrfs_alloc_workqueue("fixup", flags, 1, 0);
 
 	/*
 	 * endios are largely parallel and should have a very
 	 * low idle thresh
 	 */
-	fs_info->endio_workers.idle_thresh = 4;
-	fs_info->endio_meta_workers.idle_thresh = 4;
-	fs_info->endio_raid56_workers.idle_thresh = 4;
-	fs_info->rmw_workers.idle_thresh = 2;
-
-	fs_info->endio_write_workers.idle_thresh = 2;
-	fs_info->endio_meta_write_workers.idle_thresh = 2;
-	fs_info->readahead_workers.idle_thresh = 2;
-
-	/*
-	 * btrfs_start_workers can really only fail because of ENOMEM so just
-	 * return -ENOMEM if any of these fail.
-	 */
-	ret = btrfs_start_workers(&fs_info->workers);
-	ret |= btrfs_start_workers(&fs_info->generic_worker);
-	ret |= btrfs_start_workers(&fs_info->submit_workers);
-	ret |= btrfs_start_workers(&fs_info->delalloc_workers);
-	ret |= btrfs_start_workers(&fs_info->fixup_workers);
-	ret |= btrfs_start_workers(&fs_info->endio_workers);
-	ret |= btrfs_start_workers(&fs_info->endio_meta_workers);
-	ret |= btrfs_start_workers(&fs_info->rmw_workers);
-	ret |= btrfs_start_workers(&fs_info->endio_raid56_workers);
-	ret |= btrfs_start_workers(&fs_info->endio_meta_write_workers);
-	ret |= btrfs_start_workers(&fs_info->endio_write_workers);
-	ret |= btrfs_start_workers(&fs_info->endio_freespace_worker);
-	ret |= btrfs_start_workers(&fs_info->delayed_workers);
-	ret |= btrfs_start_workers(&fs_info->caching_workers);
-	ret |= btrfs_start_workers(&fs_info->readahead_workers);
-	ret |= btrfs_start_workers(&fs_info->flush_workers);
-	ret |= btrfs_start_workers(&fs_info->qgroup_rescan_workers);
-	if (ret) {
+	fs_info->endio_workers =
+		btrfs_alloc_workqueue("endio", flags, max_active, 4);
+	fs_info->endio_meta_workers =
+		btrfs_alloc_workqueue("endio-meta", flags, max_active, 4);
+	fs_info->endio_meta_write_workers =
+		btrfs_alloc_workqueue("endio-meta-write", flags, max_active, 2);
+	fs_info->endio_raid56_workers =
+		btrfs_alloc_workqueue("endio-raid56", flags, max_active, 4);
+	fs_info->rmw_workers =
+		btrfs_alloc_workqueue("rmw", flags, max_active, 2);
+	fs_info->endio_write_workers =
+		btrfs_alloc_workqueue("endio-write", flags, max_active, 2);
+	fs_info->endio_freespace_worker =
+		btrfs_alloc_workqueue("freespace-write", flags, max_active, 0);
+	fs_info->delayed_workers =
+		btrfs_alloc_workqueue("delayed-meta", flags, max_active, 0);
+	fs_info->readahead_workers =
+		btrfs_alloc_workqueue("readahead", flags, max_active, 2);
+	fs_info->qgroup_rescan_workers =
+		btrfs_alloc_workqueue("qgroup-rescan", flags, 1, 0);
+	fs_info->extent_workers =
+		btrfs_alloc_workqueue("extent-refs", flags,
+				      min_t(u64, fs_devices->num_devices,
+					    max_active), 8);
+
+	if (!(fs_info->workers && fs_info->delalloc_workers &&
+	      fs_info->submit_workers && fs_info->flush_workers &&
+	      fs_info->endio_workers && fs_info->endio_meta_workers &&
+	      fs_info->endio_meta_write_workers &&
+	      fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
+	      fs_info->endio_freespace_worker && fs_info->rmw_workers &&
+	      fs_info->caching_workers && fs_info->readahead_workers &&
+	      fs_info->fixup_workers && fs_info->delayed_workers &&
+	      fs_info->fixup_workers && fs_info->extent_workers &&
+	      fs_info->qgroup_rescan_workers)) {
 		err = -ENOMEM;
 		goto fail_sb_buffer;
 	}
@@ -2676,7 +2709,7 @@ retry_root_backup:
 		ret = PTR_ERR(extent_root);
 		goto recovery_tree_root;
 	}
-	extent_root->track_dirty = 1;
+	set_bit(BTRFS_ROOT_TRACK_DIRTY, &extent_root->state);
 	fs_info->extent_root = extent_root;
 
 	location.objectid = BTRFS_DEV_TREE_OBJECTID;
@@ -2685,7 +2718,7 @@ retry_root_backup:
 		ret = PTR_ERR(dev_root);
 		goto recovery_tree_root;
 	}
-	dev_root->track_dirty = 1;
+	set_bit(BTRFS_ROOT_TRACK_DIRTY, &dev_root->state);
 	fs_info->dev_root = dev_root;
 	btrfs_init_devices_late(fs_info);
 
@@ -2695,13 +2728,13 @@ retry_root_backup:
 		ret = PTR_ERR(csum_root);
 		goto recovery_tree_root;
 	}
-	csum_root->track_dirty = 1;
+	set_bit(BTRFS_ROOT_TRACK_DIRTY, &csum_root->state);
 	fs_info->csum_root = csum_root;
 
 	location.objectid = BTRFS_QUOTA_TREE_OBJECTID;
 	quota_root = btrfs_read_tree_root(tree_root, &location);
 	if (!IS_ERR(quota_root)) {
-		quota_root->track_dirty = 1;
+		set_bit(BTRFS_ROOT_TRACK_DIRTY, &quota_root->state);
 		fs_info->quota_enabled = 1;
 		fs_info->pending_quota_state = 1;
 		fs_info->quota_root = quota_root;
@@ -2716,7 +2749,7 @@ retry_root_backup:
 		create_uuid_tree = true;
 		check_uuid_tree = false;
 	} else {
-		uuid_root->track_dirty = 1;
+		set_bit(BTRFS_ROOT_TRACK_DIRTY, &uuid_root->state);
 		fs_info->uuid_root = uuid_root;
 		create_uuid_tree = false;
 		check_uuid_tree =
@@ -2844,7 +2877,7 @@ retry_root_backup:
 			printk(KERN_ERR "BTRFS: failed to read log tree\n");
 			free_extent_buffer(log_tree_root->node);
 			kfree(log_tree_root);
-			goto fail_trans_kthread;
+			goto fail_qgroup;
 		}
 		/* returns with log_tree_root freed on success */
 		ret = btrfs_recover_log_trees(log_tree_root);
@@ -2853,26 +2886,28 @@ retry_root_backup:
 				    "Failed to recover log tree");
 			free_extent_buffer(log_tree_root->node);
 			kfree(log_tree_root);
-			goto fail_trans_kthread;
+			goto fail_qgroup;
 		}
 
 		if (sb->s_flags & MS_RDONLY) {
 			ret = btrfs_commit_super(tree_root);
 			if (ret)
-				goto fail_trans_kthread;
+				goto fail_qgroup;
 		}
 	}
 
 	ret = btrfs_find_orphan_roots(tree_root);
 	if (ret)
-		goto fail_trans_kthread;
+		goto fail_qgroup;
 
 	if (!(sb->s_flags & MS_RDONLY)) {
 		ret = btrfs_cleanup_fs_roots(fs_info);
 		if (ret)
-			goto fail_trans_kthread;
+			goto fail_qgroup;
 
+		mutex_lock(&fs_info->cleaner_mutex);
 		ret = btrfs_recover_relocation(tree_root);
+		mutex_unlock(&fs_info->cleaner_mutex);
 		if (ret < 0) {
 			printk(KERN_WARNING
 			       "BTRFS: failed to recover relocation\n");
@@ -2949,7 +2984,7 @@ fail_qgroup:
 fail_trans_kthread:
 	kthread_stop(fs_info->transaction_kthread);
 	btrfs_cleanup_transaction(fs_info->tree_root);
-	del_fs_roots(fs_info);
+	btrfs_free_fs_roots(fs_info);
 fail_cleaner:
 	kthread_stop(fs_info->cleaner_kthread);
 
@@ -3484,8 +3519,10 @@ void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
 	if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
 		btrfs_free_log(NULL, root);
 
-	__btrfs_remove_free_space_cache(root->free_ino_pinned);
-	__btrfs_remove_free_space_cache(root->free_ino_ctl);
+	if (root->free_ino_pinned)
+		__btrfs_remove_free_space_cache(root->free_ino_pinned);
+	if (root->free_ino_ctl)
+		__btrfs_remove_free_space_cache(root->free_ino_ctl);
 	free_fs_root(root);
 }
 
@@ -3497,6 +3534,8 @@ static void free_fs_root(struct btrfs_root *root)
 	root->orphan_block_rsv = NULL;
 	if (root->anon_dev)
 		free_anon_bdev(root->anon_dev);
+	if (root->subv_writers)
+		btrfs_free_subvolume_writers(root->subv_writers);
 	free_extent_buffer(root->node);
 	free_extent_buffer(root->commit_root);
 	kfree(root->free_ino_ctl);
@@ -3514,28 +3553,51 @@ int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
 {
 	u64 root_objectid = 0;
 	struct btrfs_root *gang[8];
-	int i;
-	int ret;
+	int i = 0;
+	int err = 0;
+	unsigned int ret = 0;
+	int index;
 
 	while (1) {
+		index = srcu_read_lock(&fs_info->subvol_srcu);
 		ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
 					     (void **)gang, root_objectid,
 					     ARRAY_SIZE(gang));
-		if (!ret)
+		if (!ret) {
+			srcu_read_unlock(&fs_info->subvol_srcu, index);
 			break;
-
+		}
 		root_objectid = gang[ret - 1]->root_key.objectid + 1;
+
 		for (i = 0; i < ret; i++) {
-			int err;
+			/* Avoid to grab roots in dead_roots */
+			if (btrfs_root_refs(&gang[i]->root_item) == 0) {
+				gang[i] = NULL;
+				continue;
+			}
+			/* grab all the search result for later use */
+			gang[i] = btrfs_grab_fs_root(gang[i]);
+		}
+		srcu_read_unlock(&fs_info->subvol_srcu, index);
 
+		for (i = 0; i < ret; i++) {
+			if (!gang[i])
+				continue;
 			root_objectid = gang[i]->root_key.objectid;
 			err = btrfs_orphan_cleanup(gang[i]);
 			if (err)
-				return err;
+				break;
+			btrfs_put_fs_root(gang[i]);
 		}
 		root_objectid++;
 	}
-	return 0;
+
+	/* release the uncleaned roots due to error */
+	for (; i < ret; i++) {
+		if (gang[i])
+			btrfs_put_fs_root(gang[i]);
+	}
+	return err;
 }
 
 int btrfs_commit_super(struct btrfs_root *root)
@@ -3584,6 +3646,8 @@ int close_ctree(struct btrfs_root *root)
 	/* clear out the rbtree of defraggable inodes */
 	btrfs_cleanup_defrag_inodes(fs_info);
 
+	cancel_work_sync(&fs_info->async_reclaim_work);
+
 	if (!(fs_info->sb->s_flags & MS_RDONLY)) {
 		ret = btrfs_commit_super(root);
 		if (ret)
@@ -3608,12 +3672,17 @@ int close_ctree(struct btrfs_root *root)
 
 	btrfs_sysfs_remove_one(fs_info);
 
-	del_fs_roots(fs_info);
+	btrfs_free_fs_roots(fs_info);
 
 	btrfs_put_block_group_cache(fs_info);
 
 	btrfs_free_block_groups(fs_info);
 
+	/*
+	 * we must make sure there is not any read request to
+	 * submit after we stopping all workers.
+	 */
+	invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
 	btrfs_stop_all_workers(fs_info);
 
 	free_root_pointers(fs_info, 1);
@@ -3690,6 +3759,12 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
 		__percpu_counter_add(&root->fs_info->dirty_metadata_bytes,
 				     buf->len,
 				     root->fs_info->dirty_metadata_batch);
+#ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
+	if (btrfs_header_level(buf) == 0 && check_leaf(root, buf)) {
+		btrfs_print_leaf(root, buf);
+		ASSERT(0);
+	}
+#endif
 }
 
 static void __btrfs_btree_balance_dirty(struct btrfs_root *root,