Merge branch 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs updates from Chris Mason:
 "Jeff Mahoney and Dave Sterba have a really nice set of cleanups in
  here, and Christoph pitched in corrections/improvements to make btrfs
  use proper helpers for bio walking instead of doing it by hand.

  There are some key fixes as well, including some long standing bugs
  that took forever to track down in btrfs_drop_extents and during
  balance"

* 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (77 commits)
  btrfs: limit async_work allocation and worker func duration
  Revert "Btrfs: adjust len of writes if following a preallocated extent"
  Btrfs: don't WARN() in btrfs_transaction_abort() for IO errors
  btrfs: opencode chunk locking, remove helpers
  btrfs: remove root parameter from transaction commit/end routines
  btrfs: split btrfs_wait_marked_extents into normal and tree log functions
  btrfs: take an fs_info directly when the root is not used otherwise
  btrfs: simplify btrfs_wait_cache_io prototype
  btrfs: convert extent-tree tracepoints to use fs_info
  btrfs: root->fs_info cleanup, access fs_info->delayed_root directly
  btrfs: root->fs_info cleanup, add fs_info convenience variables
  btrfs: root->fs_info cleanup, update_block_group{,flags}
  btrfs: root->fs_info cleanup, lock/unlock_chunks
  btrfs: root->fs_info cleanup, btrfs_calc_{trans,trunc}_metadata_size
  btrfs: pull node/sector/stripe sizes out of root and into fs_info
  btrfs: root->fs_info cleanup, io_ctl_init
  btrfs: root->fs_info cleanup, use fs_info->dev_root everywhere
  btrfs: struct reada_control.root -> reada_control.fs_info
  btrfs: struct btrfsic_state->root should be an fs_info
  btrfs: alloc_reserved_file_extent trace point should use extent_root
  ...

1 files changed, 86 insertions, 95 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index ff3078234d94..9a94670536a6 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -171,7 +171,7 @@ struct scrub_wr_ctx {
 
 struct scrub_ctx {
 	struct scrub_bio	*bios[SCRUB_BIOS_PER_SCTX];
-	struct btrfs_root	*dev_root;
+	struct btrfs_fs_info	*fs_info;
 	int			first_free;
 	int			curr;
 	atomic_t		bios_in_flight;
@@ -356,7 +356,7 @@ static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
  */
 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
 {
-	struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 
 	atomic_inc(&sctx->refs);
 	/*
@@ -388,7 +388,7 @@ static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
 /* used for workers that require transaction commits */
 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
 {
-	struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 
 	/*
 	 * see scrub_pending_trans_workers_inc() why we're pretending
@@ -458,7 +458,7 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
 {
 	struct scrub_ctx *sctx;
 	int		i;
-	struct btrfs_fs_info *fs_info = dev->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = dev->fs_info;
 	int ret;
 
 	sctx = kzalloc(sizeof(*sctx), GFP_KERNEL);
@@ -468,7 +468,7 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
 	sctx->is_dev_replace = is_dev_replace;
 	sctx->pages_per_rd_bio = SCRUB_PAGES_PER_RD_BIO;
 	sctx->curr = -1;
-	sctx->dev_root = dev->dev_root;
+	sctx->fs_info = dev->fs_info;
 	for (i = 0; i < SCRUB_BIOS_PER_SCTX; ++i) {
 		struct scrub_bio *sbio;
 
@@ -489,8 +489,8 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
 			sctx->bios[i]->next_free = -1;
 	}
 	sctx->first_free = 0;
-	sctx->nodesize = dev->dev_root->nodesize;
-	sctx->sectorsize = dev->dev_root->sectorsize;
+	sctx->nodesize = fs_info->nodesize;
+	sctx->sectorsize = fs_info->sectorsize;
 	atomic_set(&sctx->bios_in_flight, 0);
 	atomic_set(&sctx->workers_pending, 0);
 	atomic_set(&sctx->cancel_req, 0);
@@ -524,7 +524,7 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
 	struct extent_buffer *eb;
 	struct btrfs_inode_item *inode_item;
 	struct scrub_warning *swarn = warn_ctx;
-	struct btrfs_fs_info *fs_info = swarn->dev->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = swarn->dev->fs_info;
 	struct inode_fs_paths *ipath = NULL;
 	struct btrfs_root *local_root;
 	struct btrfs_key root_key;
@@ -618,7 +618,7 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
 
 	WARN_ON(sblock->page_count < 1);
 	dev = sblock->pagev[0]->dev;
-	fs_info = sblock->sctx->dev_root->fs_info;
+	fs_info = sblock->sctx->fs_info;
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -789,6 +789,7 @@ out:
 
 static void scrub_fixup_nodatasum(struct btrfs_work *work)
 {
+	struct btrfs_fs_info *fs_info;
 	int ret;
 	struct scrub_fixup_nodatasum *fixup;
 	struct scrub_ctx *sctx;
@@ -798,6 +799,7 @@ static void scrub_fixup_nodatasum(struct btrfs_work *work)
 
 	fixup = container_of(work, struct scrub_fixup_nodatasum, work);
 	sctx = fixup->sctx;
+	fs_info = fixup->root->fs_info;
 
 	path = btrfs_alloc_path();
 	if (!path) {
@@ -823,9 +825,8 @@ static void scrub_fixup_nodatasum(struct btrfs_work *work)
 	 * (once it's finished) and rewrite the failed sector if a good copy
 	 * can be found.
 	 */
-	ret = iterate_inodes_from_logical(fixup->logical, fixup->root->fs_info,
-						path, scrub_fixup_readpage,
-						fixup);
+	ret = iterate_inodes_from_logical(fixup->logical, fs_info, path,
+					  scrub_fixup_readpage, fixup);
 	if (ret < 0) {
 		uncorrectable = 1;
 		goto out;
@@ -838,15 +839,14 @@ static void scrub_fixup_nodatasum(struct btrfs_work *work)
 
 out:
 	if (trans && !IS_ERR(trans))
-		btrfs_end_transaction(trans, fixup->root);
+		btrfs_end_transaction(trans);
 	if (uncorrectable) {
 		spin_lock(&sctx->stat_lock);
 		++sctx->stat.uncorrectable_errors;
 		spin_unlock(&sctx->stat_lock);
 		btrfs_dev_replace_stats_inc(
-			&sctx->dev_root->fs_info->dev_replace.
-			num_uncorrectable_read_errors);
-		btrfs_err_rl_in_rcu(sctx->dev_root->fs_info,
+			&fs_info->dev_replace.num_uncorrectable_read_errors);
+		btrfs_err_rl_in_rcu(fs_info,
 		    "unable to fixup (nodatasum) error at logical %llu on dev %s",
 			fixup->logical, rcu_str_deref(fixup->dev->name));
 	}
@@ -898,7 +898,7 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
 				      DEFAULT_RATELIMIT_BURST);
 
 	BUG_ON(sblock_to_check->page_count < 1);
-	fs_info = sctx->dev_root->fs_info;
+	fs_info = sctx->fs_info;
 	if (sblock_to_check->pagev[0]->flags & BTRFS_EXTENT_FLAG_SUPER) {
 		/*
 		 * if we find an error in a super block, we just report it.
@@ -1177,9 +1177,7 @@ nodatasum_case:
 			if (scrub_write_page_to_dev_replace(sblock_other,
 							    page_num) != 0) {
 				btrfs_dev_replace_stats_inc(
-					&sctx->dev_root->
-					fs_info->dev_replace.
-					num_write_errors);
+					&fs_info->dev_replace.num_write_errors);
 				success = 0;
 			}
 		} else if (sblock_other) {
@@ -1302,7 +1300,7 @@ static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
 				     struct scrub_block *sblocks_for_recheck)
 {
 	struct scrub_ctx *sctx = original_sblock->sctx;
-	struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	u64 length = original_sblock->page_count * PAGE_SIZE;
 	u64 logical = original_sblock->pagev[0]->logical;
 	u64 generation = original_sblock->pagev[0]->generation;
@@ -1334,8 +1332,8 @@ static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
 		 * with a length of PAGE_SIZE, each returned stripe
 		 * represents one mirror
 		 */
-		ret = btrfs_map_sblock(fs_info, REQ_GET_READ_MIRRORS, logical,
-				       &mapped_length, &bbio, 0, 1);
+		ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS,
+				logical, &mapped_length, &bbio, 0, 1);
 		if (ret || !bbio || mapped_length < sublen) {
 			btrfs_put_bbio(bbio);
 			return -EIO;
@@ -1452,7 +1450,7 @@ static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
 	bio->bi_private = &done;
 	bio->bi_end_io = scrub_bio_wait_endio;
 
-	ret = raid56_parity_recover(fs_info->fs_root, bio, page->recover->bbio,
+	ret = raid56_parity_recover(fs_info, bio, page->recover->bbio,
 				    page->recover->map_length,
 				    page->mirror_num, 0);
 	if (ret)
@@ -1565,6 +1563,7 @@ static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
 {
 	struct scrub_page *page_bad = sblock_bad->pagev[page_num];
 	struct scrub_page *page_good = sblock_good->pagev[page_num];
+	struct btrfs_fs_info *fs_info = sblock_bad->sctx->fs_info;
 
 	BUG_ON(page_bad->page == NULL);
 	BUG_ON(page_good->page == NULL);
@@ -1574,7 +1573,7 @@ static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
 		int ret;
 
 		if (!page_bad->dev->bdev) {
-			btrfs_warn_rl(sblock_bad->sctx->dev_root->fs_info,
+			btrfs_warn_rl(fs_info,
 				"scrub_repair_page_from_good_copy(bdev == NULL) is unexpected");
 			return -EIO;
 		}
@@ -1596,8 +1595,7 @@ static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
 			btrfs_dev_stat_inc_and_print(page_bad->dev,
 				BTRFS_DEV_STAT_WRITE_ERRS);
 			btrfs_dev_replace_stats_inc(
-				&sblock_bad->sctx->dev_root->fs_info->
-				dev_replace.num_write_errors);
+				&fs_info->dev_replace.num_write_errors);
 			bio_put(bio);
 			return -EIO;
 		}
@@ -1609,6 +1607,7 @@ static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
 
 static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
 {
+	struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
 	int page_num;
 
 	/*
@@ -1624,8 +1623,7 @@ static void scrub_write_block_to_dev_replace(struct scrub_block *sblock)
 		ret = scrub_write_page_to_dev_replace(sblock, page_num);
 		if (ret)
 			btrfs_dev_replace_stats_inc(
-				&sblock->sctx->dev_root->fs_info->dev_replace.
-				num_write_errors);
+				&fs_info->dev_replace.num_write_errors);
 	}
 }
 
@@ -1740,7 +1738,7 @@ static void scrub_wr_submit(struct scrub_ctx *sctx)
 static void scrub_wr_bio_end_io(struct bio *bio)
 {
 	struct scrub_bio *sbio = bio->bi_private;
-	struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
 
 	sbio->err = bio->bi_error;
 	sbio->bio = bio;
@@ -1759,7 +1757,7 @@ static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
 	WARN_ON(sbio->page_count > SCRUB_PAGES_PER_WR_BIO);
 	if (sbio->err) {
 		struct btrfs_dev_replace *dev_replace =
-			&sbio->sctx->dev_root->fs_info->dev_replace;
+			&sbio->sctx->fs_info->dev_replace;
 
 		for (i = 0; i < sbio->page_count; i++) {
 			struct scrub_page *spage = sbio->pagev[i];
@@ -1859,8 +1857,7 @@ static int scrub_checksum_tree_block(struct scrub_block *sblock)
 {
 	struct scrub_ctx *sctx = sblock->sctx;
 	struct btrfs_header *h;
-	struct btrfs_root *root = sctx->dev_root;
-	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	u8 calculated_csum[BTRFS_CSUM_SIZE];
 	u8 on_disk_csum[BTRFS_CSUM_SIZE];
 	struct page *page;
@@ -2126,7 +2123,7 @@ again:
 static void scrub_missing_raid56_end_io(struct bio *bio)
 {
 	struct scrub_block *sblock = bio->bi_private;
-	struct btrfs_fs_info *fs_info = sblock->sctx->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;
 
 	if (bio->bi_error)
 		sblock->no_io_error_seen = 0;
@@ -2140,6 +2137,7 @@ static void scrub_missing_raid56_worker(struct btrfs_work *work)
 {
 	struct scrub_block *sblock = container_of(work, struct scrub_block, work);
 	struct scrub_ctx *sctx = sblock->sctx;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	u64 logical;
 	struct btrfs_device *dev;
 
@@ -2153,14 +2151,14 @@ static void scrub_missing_raid56_worker(struct btrfs_work *work)
 		spin_lock(&sctx->stat_lock);
 		sctx->stat.read_errors++;
 		spin_unlock(&sctx->stat_lock);
-		btrfs_err_rl_in_rcu(sctx->dev_root->fs_info,
+		btrfs_err_rl_in_rcu(fs_info,
 			"IO error rebuilding logical %llu for dev %s",
 			logical, rcu_str_deref(dev->name));
 	} else if (sblock->header_error || sblock->checksum_error) {
 		spin_lock(&sctx->stat_lock);
 		sctx->stat.uncorrectable_errors++;
 		spin_unlock(&sctx->stat_lock);
-		btrfs_err_rl_in_rcu(sctx->dev_root->fs_info,
+		btrfs_err_rl_in_rcu(fs_info,
 			"failed to rebuild valid logical %llu for dev %s",
 			logical, rcu_str_deref(dev->name));
 	} else {
@@ -2182,7 +2180,7 @@ static void scrub_missing_raid56_worker(struct btrfs_work *work)
 static void scrub_missing_raid56_pages(struct scrub_block *sblock)
 {
 	struct scrub_ctx *sctx = sblock->sctx;
-	struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	u64 length = sblock->page_count * PAGE_SIZE;
 	u64 logical = sblock->pagev[0]->logical;
 	struct btrfs_bio *bbio = NULL;
@@ -2191,8 +2189,8 @@ static void scrub_missing_raid56_pages(struct scrub_block *sblock)
 	int ret;
 	int i;
 
-	ret = btrfs_map_sblock(fs_info, REQ_GET_READ_MIRRORS, logical, &length,
-			       &bbio, 0, 1);
+	ret = btrfs_map_sblock(fs_info, BTRFS_MAP_GET_READ_MIRRORS, logical,
+			&length, &bbio, 0, 1);
 	if (ret || !bbio || !bbio->raid_map)
 		goto bbio_out;
 
@@ -2215,7 +2213,7 @@ static void scrub_missing_raid56_pages(struct scrub_block *sblock)
 	bio->bi_private = sblock;
 	bio->bi_end_io = scrub_missing_raid56_end_io;
 
-	rbio = raid56_alloc_missing_rbio(sctx->dev_root, bio, bbio, length);
+	rbio = raid56_alloc_missing_rbio(fs_info, bio, bbio, length);
 	if (!rbio)
 		goto rbio_out;
 
@@ -2334,7 +2332,7 @@ leave_nomem:
 static void scrub_bio_end_io(struct bio *bio)
 {
 	struct scrub_bio *sbio = bio->bi_private;
-	struct btrfs_fs_info *fs_info = sbio->dev->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = sbio->dev->fs_info;
 
 	sbio->err = bio->bi_error;
 	sbio->bio = bio;
@@ -2391,7 +2389,7 @@ static inline void __scrub_mark_bitmap(struct scrub_parity *sparity,
 {
 	u32 offset;
 	int nsectors;
-	int sectorsize = sparity->sctx->dev_root->sectorsize;
+	int sectorsize = sparity->sctx->fs_info->sectorsize;
 
 	if (len >= sparity->stripe_len) {
 		bitmap_set(bitmap, 0, sparity->nsectors);
@@ -2750,6 +2748,7 @@ static void scrub_parity_bio_endio_worker(struct btrfs_work *work)
 static void scrub_parity_bio_endio(struct bio *bio)
 {
 	struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private;
+	struct btrfs_fs_info *fs_info = sparity->sctx->fs_info;
 
 	if (bio->bi_error)
 		bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
@@ -2759,13 +2758,13 @@ static void scrub_parity_bio_endio(struct bio *bio)
 
 	btrfs_init_work(&sparity->work, btrfs_scrubparity_helper,
 			scrub_parity_bio_endio_worker, NULL, NULL);
-	btrfs_queue_work(sparity->sctx->dev_root->fs_info->scrub_parity_workers,
-			 &sparity->work);
+	btrfs_queue_work(fs_info->scrub_parity_workers, &sparity->work);
 }
 
 static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
 {
 	struct scrub_ctx *sctx = sparity->sctx;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	struct bio *bio;
 	struct btrfs_raid_bio *rbio;
 	struct scrub_page *spage;
@@ -2778,8 +2777,7 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
 		goto out;
 
 	length = sparity->logic_end - sparity->logic_start;
-	ret = btrfs_map_sblock(sctx->dev_root->fs_info, WRITE,
-			       sparity->logic_start,
+	ret = btrfs_map_sblock(fs_info, BTRFS_MAP_WRITE, sparity->logic_start,
 			       &length, &bbio, 0, 1);
 	if (ret || !bbio || !bbio->raid_map)
 		goto bbio_out;
@@ -2792,7 +2790,7 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
 	bio->bi_private = sparity;
 	bio->bi_end_io = scrub_parity_bio_endio;
 
-	rbio = raid56_parity_alloc_scrub_rbio(sctx->dev_root, bio, bbio,
+	rbio = raid56_parity_alloc_scrub_rbio(fs_info, bio, bbio,
 					      length, sparity->scrub_dev,
 					      sparity->dbitmap,
 					      sparity->nsectors);
@@ -2844,7 +2842,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
 						  u64 logic_start,
 						  u64 logic_end)
 {
-	struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	struct btrfs_root *root = fs_info->extent_root;
 	struct btrfs_root *csum_root = fs_info->csum_root;
 	struct btrfs_extent_item *extent;
@@ -2866,7 +2864,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
 	int extent_mirror_num;
 	int stop_loop = 0;
 
-	nsectors = div_u64(map->stripe_len, root->sectorsize);
+	nsectors = div_u64(map->stripe_len, fs_info->sectorsize);
 	bitmap_len = scrub_calc_parity_bitmap_len(nsectors);
 	sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len,
 			  GFP_NOFS);
@@ -2937,7 +2935,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
 				goto next;
 
 			if (key.type == BTRFS_METADATA_ITEM_KEY)
-				bytes = root->nodesize;
+				bytes = fs_info->nodesize;
 			else
 				bytes = key.offset;
 
@@ -2988,8 +2986,9 @@ again:
 
 			mapped_length = extent_len;
 			bbio = NULL;
-			ret = btrfs_map_block(fs_info, READ, extent_logical,
-					      &mapped_length, &bbio, 0);
+			ret = btrfs_map_block(fs_info, BTRFS_MAP_READ,
+					extent_logical, &mapped_length, &bbio,
+					0);
 			if (!ret) {
 				if (!bbio || mapped_length < extent_len)
 					ret = -EIO;
@@ -3068,7 +3067,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 					   int is_dev_replace)
 {
 	struct btrfs_path *path, *ppath;
-	struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 	struct btrfs_root *root = fs_info->extent_root;
 	struct btrfs_root *csum_root = fs_info->csum_root;
 	struct btrfs_extent_item *extent;
@@ -3289,7 +3288,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 				goto next;
 
 			if (key.type == BTRFS_METADATA_ITEM_KEY)
-				bytes = root->nodesize;
+				bytes = fs_info->nodesize;
 			else
 				bytes = key.offset;
 
@@ -3442,8 +3441,8 @@ static noinline_for_stack int scrub_chunk(struct scrub_ctx *sctx,
 					  struct btrfs_block_group_cache *cache,
 					  int is_dev_replace)
 {
-	struct btrfs_mapping_tree *map_tree =
-		&sctx->dev_root->fs_info->mapping_tree;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
+	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
 	struct map_lookup *map;
 	struct extent_map *em;
 	int i;
@@ -3496,8 +3495,8 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 {
 	struct btrfs_dev_extent *dev_extent = NULL;
 	struct btrfs_path *path;
-	struct btrfs_root *root = sctx->dev_root;
-	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
+	struct btrfs_root *root = fs_info->dev_root;
 	u64 length;
 	u64 chunk_offset;
 	int ret = 0;
@@ -3617,8 +3616,7 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 				if (IS_ERR(trans))
 					ret = PTR_ERR(trans);
 				else
-					ret = btrfs_commit_transaction(trans,
-								       root);
+					ret = btrfs_commit_transaction(trans);
 				if (ret) {
 					scrub_pause_off(fs_info);
 					btrfs_put_block_group(cache);
@@ -3693,7 +3691,7 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx,
 		btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);
 
 		if (ro_set)
-			btrfs_dec_block_group_ro(root, cache);
+			btrfs_dec_block_group_ro(cache);
 
 		/*
 		 * We might have prevented the cleaner kthread from deleting
@@ -3746,16 +3744,16 @@ static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
 	u64	bytenr;
 	u64	gen;
 	int	ret;
-	struct btrfs_root *root = sctx->dev_root;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 
-	if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
+	if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
 		return -EIO;
 
 	/* Seed devices of a new filesystem has their own generation. */
-	if (scrub_dev->fs_devices != root->fs_info->fs_devices)
+	if (scrub_dev->fs_devices != fs_info->fs_devices)
 		gen = scrub_dev->generation;
 	else
-		gen = root->fs_info->last_trans_committed;
+		gen = fs_info->last_trans_committed;
 
 	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
 		bytenr = btrfs_sb_offset(i);
@@ -3847,7 +3845,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
 	if (btrfs_fs_closing(fs_info))
 		return -EINVAL;
 
-	if (fs_info->chunk_root->nodesize > BTRFS_STRIPE_LEN) {
+	if (fs_info->nodesize > BTRFS_STRIPE_LEN) {
 		/*
 		 * in this case scrub is unable to calculate the checksum
 		 * the way scrub is implemented. Do not handle this
@@ -3855,31 +3853,31 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
 		 */
 		btrfs_err(fs_info,
 			   "scrub: size assumption nodesize <= BTRFS_STRIPE_LEN (%d <= %d) fails",
-		       fs_info->chunk_root->nodesize, BTRFS_STRIPE_LEN);
+		       fs_info->nodesize,
+		       BTRFS_STRIPE_LEN);
 		return -EINVAL;
 	}
 
-	if (fs_info->chunk_root->sectorsize != PAGE_SIZE) {
+	if (fs_info->sectorsize != PAGE_SIZE) {
 		/* not supported for data w/o checksums */
 		btrfs_err_rl(fs_info,
 			   "scrub: size assumption sectorsize != PAGE_SIZE (%d != %lu) fails",
-		       fs_info->chunk_root->sectorsize, PAGE_SIZE);
+		       fs_info->sectorsize, PAGE_SIZE);
 		return -EINVAL;
 	}
 
-	if (fs_info->chunk_root->nodesize >
+	if (fs_info->nodesize >
 	    PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK ||
-	    fs_info->chunk_root->sectorsize >
-	    PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
+	    fs_info->sectorsize > PAGE_SIZE * SCRUB_MAX_PAGES_PER_BLOCK) {
 		/*
 		 * would exhaust the array bounds of pagev member in
 		 * struct scrub_block
 		 */
 		btrfs_err(fs_info,
 			  "scrub: size assumption nodesize and sectorsize <= SCRUB_MAX_PAGES_PER_BLOCK (%d <= %d && %d <= %d) fails",
-		       fs_info->chunk_root->nodesize,
+		       fs_info->nodesize,
 		       SCRUB_MAX_PAGES_PER_BLOCK,
-		       fs_info->chunk_root->sectorsize,
+		       fs_info->sectorsize,
 		       SCRUB_MAX_PAGES_PER_BLOCK);
 		return -EINVAL;
 	}
@@ -3979,10 +3977,8 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
 	return ret;
 }
 
-void btrfs_scrub_pause(struct btrfs_root *root)
+void btrfs_scrub_pause(struct btrfs_fs_info *fs_info)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
-
 	mutex_lock(&fs_info->scrub_lock);
 	atomic_inc(&fs_info->scrub_pause_req);
 	while (atomic_read(&fs_info->scrubs_paused) !=
@@ -3996,10 +3992,8 @@ void btrfs_scrub_pause(struct btrfs_root *root)
 	mutex_unlock(&fs_info->scrub_lock);
 }
 
-void btrfs_scrub_continue(struct btrfs_root *root)
+void btrfs_scrub_continue(struct btrfs_fs_info *fs_info)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
-
 	atomic_dec(&fs_info->scrub_pause_req);
 	wake_up(&fs_info->scrub_pause_wait);
 }
@@ -4048,19 +4042,19 @@ int btrfs_scrub_cancel_dev(struct btrfs_fs_info *fs_info,
 	return 0;
 }
 
-int btrfs_scrub_progress(struct btrfs_root *root, u64 devid,
+int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
 			 struct btrfs_scrub_progress *progress)
 {
 	struct btrfs_device *dev;
 	struct scrub_ctx *sctx = NULL;
 
-	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
-	dev = btrfs_find_device(root->fs_info, devid, NULL, NULL);
+	mutex_lock(&fs_info->fs_devices->device_list_mutex);
+	dev = btrfs_find_device(fs_info, devid, NULL, NULL);
 	if (dev)
 		sctx = dev->scrub_device;
 	if (sctx)
 		memcpy(progress, &sctx->stat, sizeof(*progress));
-	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
+	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
 
 	return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV;
 }
@@ -4076,7 +4070,7 @@ static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
 	int ret;
 
 	mapped_length = extent_len;
-	ret = btrfs_map_block(fs_info, READ, extent_logical,
+	ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical,
 			      &mapped_length, &bbio, 0);
 	if (ret || !bbio || mapped_length < extent_len ||
 	    !bbio->stripes[0].dev->bdev) {
@@ -4122,7 +4116,7 @@ static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
 			    int mirror_num, u64 physical_for_dev_replace)
 {
 	struct scrub_copy_nocow_ctx *nocow_ctx;
-	struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
 
 	nocow_ctx = kzalloc(sizeof(*nocow_ctx), GFP_NOFS);
 	if (!nocow_ctx) {
@@ -4170,20 +4164,17 @@ static void copy_nocow_pages_worker(struct btrfs_work *work)
 	struct scrub_copy_nocow_ctx *nocow_ctx =
 		container_of(work, struct scrub_copy_nocow_ctx, work);
 	struct scrub_ctx *sctx = nocow_ctx->sctx;
+	struct btrfs_fs_info *fs_info = sctx->fs_info;
+	struct btrfs_root *root = fs_info->extent_root;
 	u64 logical = nocow_ctx->logical;
 	u64 len = nocow_ctx->len;
 	int mirror_num = nocow_ctx->mirror_num;
 	u64 physical_for_dev_replace = nocow_ctx->physical_for_dev_replace;
 	int ret;
 	struct btrfs_trans_handle *trans = NULL;
-	struct btrfs_fs_info *fs_info;
 	struct btrfs_path *path;
-	struct btrfs_root *root;
 	int not_written = 0;
 
-	fs_info = sctx->dev_root->fs_info;
-	root = fs_info->extent_root;
-
 	path = btrfs_alloc_path();
 	if (!path) {
 		spin_lock(&sctx->stat_lock);
@@ -4210,7 +4201,7 @@ static void copy_nocow_pages_worker(struct btrfs_work *work)
 		goto out;
 	}
 
-	btrfs_end_transaction(trans, root);
+	btrfs_end_transaction(trans);
 	trans = NULL;
 	while (!list_empty(&nocow_ctx->inodes)) {
 		struct scrub_nocow_inode *entry;
@@ -4238,7 +4229,7 @@ out:
 		kfree(entry);
 	}
 	if (trans && !IS_ERR(trans))
-		btrfs_end_transaction(trans, root);
+		btrfs_end_transaction(trans);
 	if (not_written)
 		btrfs_dev_replace_stats_inc(&fs_info->dev_replace.
 					    num_uncorrectable_read_errors);
@@ -4296,7 +4287,7 @@ out_unlock:
 static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
 				      struct scrub_copy_nocow_ctx *nocow_ctx)
 {
-	struct btrfs_fs_info *fs_info = nocow_ctx->sctx->dev_root->fs_info;
+	struct btrfs_fs_info *fs_info = nocow_ctx->sctx->fs_info;
 	struct btrfs_key key;
 	struct inode *inode;
 	struct page *page;
@@ -4426,7 +4417,7 @@ static int write_page_nocow(struct scrub_ctx *sctx,
 	if (!dev)
 		return -EIO;
 	if (!dev->bdev) {
-		btrfs_warn_rl(dev->dev_root->fs_info,
+		btrfs_warn_rl(dev->fs_info,
 			"scrub write_page_nocow(bdev == NULL) is unexpected");
 		return -EIO;
 	}