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

Pull btrfs updates from Chris Mason:
 "This pull is mostly cleanups and fixes:

   - The raid5/6 cleanups from Zhao Lei fixup some long standing warts
     in the code and add improvements on top of the scrubbing support
     from 3.19.

   - Josef has round one of our ENOSPC fixes coming from large btrfs
     clusters here at FB.

   - Dave Sterba continues a long series of cleanups (thanks Dave), and
     Filipe continues hammering on corner cases in fsync and others

  This all was held up a little trying to track down a use-after-free in
  btrfs raid5/6.  It's not clear yet if this is just made easier to
  trigger with this pull or if its a new bug from the raid5/6 cleanups.
  Dave Sterba is the only one to trigger it so far, but he has a
  consistent way to reproduce, so we'll get it nailed shortly"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (68 commits)
  Btrfs: don't remove extents and xattrs when logging new names
  Btrfs: fix fsync data loss after adding hard link to inode
  Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group
  Btrfs: account for large extents with enospc
  Btrfs: don't set and clear delalloc for O_DIRECT writes
  Btrfs: only adjust outstanding_extents when we do a short write
  btrfs: Fix out-of-space bug
  Btrfs: scrub, fix sleep in atomic context
  Btrfs: fix scheduler warning when syncing log
  Btrfs: Remove unnecessary placeholder in btrfs_err_code
  btrfs: cleanup init for list in free-space-cache
  btrfs: delete chunk allocation attemp when setting block group ro
  btrfs: clear bio reference after submit_one_bio()
  Btrfs: fix scrub race leading to use-after-free
  Btrfs: add missing cleanup on sysfs init failure
  Btrfs: fix race between transaction commit and empty block group removal
  btrfs: add more checks to btrfs_read_sys_array
  btrfs: cleanup, rename a few variables in btrfs_read_sys_array
  btrfs: add checks for sys_chunk_array sizes
  btrfs: more superblock checks, lower bounds on devices and sectorsize/nodesize
  ...

1 files changed, 141 insertions, 168 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index e427cb7ee12c..ec57687c9a4d 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -66,7 +66,6 @@ struct scrub_ctx;
 struct scrub_recover {
 	atomic_t		refs;
 	struct btrfs_bio	*bbio;
-	u64			*raid_map;
 	u64			map_length;
 };
 
@@ -80,7 +79,7 @@ struct scrub_page {
 	u64			logical;
 	u64			physical;
 	u64			physical_for_dev_replace;
-	atomic_t		ref_count;
+	atomic_t		refs;
 	struct {
 		unsigned int	mirror_num:8;
 		unsigned int	have_csum:1;
@@ -113,7 +112,7 @@ struct scrub_block {
 	struct scrub_page	*pagev[SCRUB_MAX_PAGES_PER_BLOCK];
 	int			page_count;
 	atomic_t		outstanding_pages;
-	atomic_t		ref_count; /* free mem on transition to zero */
+	atomic_t		refs; /* free mem on transition to zero */
 	struct scrub_ctx	*sctx;
 	struct scrub_parity	*sparity;
 	struct {
@@ -142,7 +141,7 @@ struct scrub_parity {
 
 	int			stripe_len;
 
-	atomic_t		ref_count;
+	atomic_t		refs;
 
 	struct list_head	spages;
 
@@ -194,6 +193,15 @@ struct scrub_ctx {
 	 */
 	struct btrfs_scrub_progress stat;
 	spinlock_t		stat_lock;
+
+	/*
+	 * Use a ref counter to avoid use-after-free issues. Scrub workers
+	 * decrement bios_in_flight and workers_pending and then do a wakeup
+	 * on the list_wait wait queue. We must ensure the main scrub task
+	 * doesn't free the scrub context before or while the workers are
+	 * doing the wakeup() call.
+	 */
+	atomic_t                refs;
 };
 
 struct scrub_fixup_nodatasum {
@@ -236,10 +244,7 @@ static void scrub_pending_bio_dec(struct scrub_ctx *sctx);
 static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx);
 static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx);
 static int scrub_handle_errored_block(struct scrub_block *sblock_to_check);
-static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
-				     struct btrfs_fs_info *fs_info,
-				     struct scrub_block *original_sblock,
-				     u64 length, u64 logical,
+static int scrub_setup_recheck_block(struct scrub_block *original_sblock,
 				     struct scrub_block *sblocks_for_recheck);
 static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
 				struct scrub_block *sblock, int is_metadata,
@@ -251,8 +256,7 @@ static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
 					 const u8 *csum, u64 generation,
 					 u16 csum_size);
 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
-					     struct scrub_block *sblock_good,
-					     int force_write);
+					     struct scrub_block *sblock_good);
 static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
 					    struct scrub_block *sblock_good,
 					    int page_num, int force_write);
@@ -302,10 +306,12 @@ static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
 static void copy_nocow_pages_worker(struct btrfs_work *work);
 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
 static void scrub_blocked_if_needed(struct btrfs_fs_info *fs_info);
+static void scrub_put_ctx(struct scrub_ctx *sctx);
 
 
 static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
 {
+	atomic_inc(&sctx->refs);
 	atomic_inc(&sctx->bios_in_flight);
 }
 
@@ -313,6 +319,7 @@ static void scrub_pending_bio_dec(struct scrub_ctx *sctx)
 {
 	atomic_dec(&sctx->bios_in_flight);
 	wake_up(&sctx->list_wait);
+	scrub_put_ctx(sctx);
 }
 
 static void __scrub_blocked_if_needed(struct btrfs_fs_info *fs_info)
@@ -346,6 +353,7 @@ static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx)
 {
 	struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
 
+	atomic_inc(&sctx->refs);
 	/*
 	 * increment scrubs_running to prevent cancel requests from
 	 * completing as long as a worker is running. we must also
@@ -388,6 +396,7 @@ static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx)
 	atomic_dec(&sctx->workers_pending);
 	wake_up(&fs_info->scrub_pause_wait);
 	wake_up(&sctx->list_wait);
+	scrub_put_ctx(sctx);
 }
 
 static void scrub_free_csums(struct scrub_ctx *sctx)
@@ -433,6 +442,12 @@ static noinline_for_stack void scrub_free_ctx(struct scrub_ctx *sctx)
 	kfree(sctx);
 }
 
+static void scrub_put_ctx(struct scrub_ctx *sctx)
+{
+	if (atomic_dec_and_test(&sctx->refs))
+		scrub_free_ctx(sctx);
+}
+
 static noinline_for_stack
 struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
 {
@@ -457,6 +472,7 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
 	sctx = kzalloc(sizeof(*sctx), GFP_NOFS);
 	if (!sctx)
 		goto nomem;
+	atomic_set(&sctx->refs, 1);
 	sctx->is_dev_replace = is_dev_replace;
 	sctx->pages_per_rd_bio = pages_per_rd_bio;
 	sctx->curr = -1;
@@ -520,6 +536,7 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
 	struct inode_fs_paths *ipath = NULL;
 	struct btrfs_root *local_root;
 	struct btrfs_key root_key;
+	struct btrfs_key key;
 
 	root_key.objectid = root;
 	root_key.type = BTRFS_ROOT_ITEM_KEY;
@@ -530,7 +547,14 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
 		goto err;
 	}
 
-	ret = inode_item_info(inum, 0, local_root, swarn->path);
+	/*
+	 * this makes the path point to (inum INODE_ITEM ioff)
+	 */
+	key.objectid = inum;
+	key.type = BTRFS_INODE_ITEM_KEY;
+	key.offset = 0;
+
+	ret = btrfs_search_slot(NULL, local_root, &key, swarn->path, 0, 0);
 	if (ret) {
 		btrfs_release_path(swarn->path);
 		goto err;
@@ -848,8 +872,7 @@ static inline void scrub_get_recover(struct scrub_recover *recover)
 static inline void scrub_put_recover(struct scrub_recover *recover)
 {
 	if (atomic_dec_and_test(&recover->refs)) {
-		kfree(recover->bbio);
-		kfree(recover->raid_map);
+		btrfs_put_bbio(recover->bbio);
 		kfree(recover);
 	}
 }
@@ -955,8 +978,7 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
 	}
 
 	/* setup the context, map the logical blocks and alloc the pages */
-	ret = scrub_setup_recheck_block(sctx, fs_info, sblock_to_check, length,
-					logical, sblocks_for_recheck);
+	ret = scrub_setup_recheck_block(sblock_to_check, sblocks_for_recheck);
 	if (ret) {
 		spin_lock(&sctx->stat_lock);
 		sctx->stat.read_errors++;
@@ -1030,9 +1052,10 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
 	if (!is_metadata && !have_csum) {
 		struct scrub_fixup_nodatasum *fixup_nodatasum;
 
-nodatasum_case:
 		WARN_ON(sctx->is_dev_replace);
 
+nodatasum_case:
+
 		/*
 		 * !is_metadata and !have_csum, this means that the data
 		 * might not be COW'ed, that it might be modified
@@ -1091,76 +1114,20 @@ nodatasum_case:
 		    sblock_other->no_io_error_seen) {
 			if (sctx->is_dev_replace) {
 				scrub_write_block_to_dev_replace(sblock_other);
+				goto corrected_error;
 			} else {
-				int force_write = is_metadata || have_csum;
-
 				ret = scrub_repair_block_from_good_copy(
-						sblock_bad, sblock_other,
-						force_write);
+						sblock_bad, sblock_other);
+				if (!ret)
+					goto corrected_error;
 			}
-			if (0 == ret)
-				goto corrected_error;
 		}
 	}
 
-	/*
-	 * for dev_replace, pick good pages and write to the target device.
-	 */
-	if (sctx->is_dev_replace) {
-		success = 1;
-		for (page_num = 0; page_num < sblock_bad->page_count;
-		     page_num++) {
-			int sub_success;
-
-			sub_success = 0;
-			for (mirror_index = 0;
-			     mirror_index < BTRFS_MAX_MIRRORS &&
-			     sblocks_for_recheck[mirror_index].page_count > 0;
-			     mirror_index++) {
-				struct scrub_block *sblock_other =
-					sblocks_for_recheck + mirror_index;
-				struct scrub_page *page_other =
-					sblock_other->pagev[page_num];
-
-				if (!page_other->io_error) {
-					ret = scrub_write_page_to_dev_replace(
-							sblock_other, page_num);
-					if (ret == 0) {
-						/* succeeded for this page */
-						sub_success = 1;
-						break;
-					} else {
-						btrfs_dev_replace_stats_inc(
-							&sctx->dev_root->
-							fs_info->dev_replace.
-							num_write_errors);
-					}
-				}
-			}
-
-			if (!sub_success) {
-				/*
-				 * did not find a mirror to fetch the page
-				 * from. scrub_write_page_to_dev_replace()
-				 * handles this case (page->io_error), by
-				 * filling the block with zeros before
-				 * submitting the write request
-				 */
-				success = 0;
-				ret = scrub_write_page_to_dev_replace(
-						sblock_bad, page_num);
-				if (ret)
-					btrfs_dev_replace_stats_inc(
-						&sctx->dev_root->fs_info->
-						dev_replace.num_write_errors);
-			}
-		}
-
-		goto out;
-	}
+	if (sblock_bad->no_io_error_seen && !sctx->is_dev_replace)
+		goto did_not_correct_error;
 
 	/*
-	 * for regular scrub, repair those pages that are errored.
 	 * In case of I/O errors in the area that is supposed to be
 	 * repaired, continue by picking good copies of those pages.
 	 * Select the good pages from mirrors to rewrite bad pages from
@@ -1184,44 +1151,64 @@ nodatasum_case:
 	 * mirror, even if other 512 byte sectors in the same PAGE_SIZE
 	 * area are unreadable.
 	 */
-
-	/* can only fix I/O errors from here on */
-	if (sblock_bad->no_io_error_seen)
-		goto did_not_correct_error;
-
 	success = 1;
-	for (page_num = 0; page_num < sblock_bad->page_count; page_num++) {
+	for (page_num = 0; page_num < sblock_bad->page_count;
+	     page_num++) {
 		struct scrub_page *page_bad = sblock_bad->pagev[page_num];
+		struct scrub_block *sblock_other = NULL;
 
-		if (!page_bad->io_error)
+		/* skip no-io-error page in scrub */
+		if (!page_bad->io_error && !sctx->is_dev_replace)
 			continue;
 
-		for (mirror_index = 0;
-		     mirror_index < BTRFS_MAX_MIRRORS &&
-		     sblocks_for_recheck[mirror_index].page_count > 0;
-		     mirror_index++) {
-			struct scrub_block *sblock_other = sblocks_for_recheck +
-							   mirror_index;
-			struct scrub_page *page_other = sblock_other->pagev[
-							page_num];
-
-			if (!page_other->io_error) {
-				ret = scrub_repair_page_from_good_copy(
-					sblock_bad, sblock_other, page_num, 0);
-				if (0 == ret) {
-					page_bad->io_error = 0;
-					break; /* succeeded for this page */
+		/* try to find no-io-error page in mirrors */
+		if (page_bad->io_error) {
+			for (mirror_index = 0;
+			     mirror_index < BTRFS_MAX_MIRRORS &&
+			     sblocks_for_recheck[mirror_index].page_count > 0;
+			     mirror_index++) {
+				if (!sblocks_for_recheck[mirror_index].
+				    pagev[page_num]->io_error) {
+					sblock_other = sblocks_for_recheck +
+						       mirror_index;
+					break;
 				}
 			}
+			if (!sblock_other)
+				success = 0;
 		}
 
-		if (page_bad->io_error) {
-			/* did not find a mirror to copy the page from */
-			success = 0;
+		if (sctx->is_dev_replace) {
+			/*
+			 * did not find a mirror to fetch the page
+			 * from. scrub_write_page_to_dev_replace()
+			 * handles this case (page->io_error), by
+			 * filling the block with zeros before
+			 * submitting the write request
+			 */
+			if (!sblock_other)
+				sblock_other = sblock_bad;
+
+			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);
+				success = 0;
+			}
+		} else if (sblock_other) {
+			ret = scrub_repair_page_from_good_copy(sblock_bad,
+							       sblock_other,
+							       page_num, 0);
+			if (0 == ret)
+				page_bad->io_error = 0;
+			else
+				success = 0;
 		}
 	}
 
-	if (success) {
+	if (success && !sctx->is_dev_replace) {
 		if (is_metadata || have_csum) {
 			/*
 			 * need to verify the checksum now that all
@@ -1288,19 +1275,18 @@ out:
 	return 0;
 }
 
-static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio, u64 *raid_map)
+static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio)
 {
-	if (raid_map) {
-		if (raid_map[bbio->num_stripes - 1] == RAID6_Q_STRIPE)
-			return 3;
-		else
-			return 2;
-	} else {
+	if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
+		return 2;
+	else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
+		return 3;
+	else
 		return (int)bbio->num_stripes;
-	}
 }
 
-static inline void scrub_stripe_index_and_offset(u64 logical, u64 *raid_map,
+static inline void scrub_stripe_index_and_offset(u64 logical, u64 map_type,
+						 u64 *raid_map,
 						 u64 mapped_length,
 						 int nstripes, int mirror,
 						 int *stripe_index,
@@ -1308,7 +1294,7 @@ static inline void scrub_stripe_index_and_offset(u64 logical, u64 *raid_map,
 {
 	int i;
 
-	if (raid_map) {
+	if (map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
 		/* RAID5/6 */
 		for (i = 0; i < nstripes; i++) {
 			if (raid_map[i] == RAID6_Q_STRIPE ||
@@ -1329,72 +1315,65 @@ static inline void scrub_stripe_index_and_offset(u64 logical, u64 *raid_map,
 	}
 }
 
-static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
-				     struct btrfs_fs_info *fs_info,
-				     struct scrub_block *original_sblock,
-				     u64 length, u64 logical,
+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;
+	u64 length = original_sblock->page_count * PAGE_SIZE;
+	u64 logical = original_sblock->pagev[0]->logical;
 	struct scrub_recover *recover;
 	struct btrfs_bio *bbio;
-	u64 *raid_map;
 	u64 sublen;
 	u64 mapped_length;
 	u64 stripe_offset;
 	int stripe_index;
-	int page_index;
+	int page_index = 0;
 	int mirror_index;
 	int nmirrors;
 	int ret;
 
 	/*
-	 * note: the two members ref_count and outstanding_pages
+	 * note: the two members refs and outstanding_pages
 	 * are not used (and not set) in the blocks that are used for
 	 * the recheck procedure
 	 */
 
-	page_index = 0;
 	while (length > 0) {
 		sublen = min_t(u64, length, PAGE_SIZE);
 		mapped_length = sublen;
 		bbio = NULL;
-		raid_map = NULL;
 
 		/*
 		 * 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, &raid_map);
+				       &mapped_length, &bbio, 0, 1);
 		if (ret || !bbio || mapped_length < sublen) {
-			kfree(bbio);
-			kfree(raid_map);
+			btrfs_put_bbio(bbio);
 			return -EIO;
 		}
 
 		recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS);
 		if (!recover) {
-			kfree(bbio);
-			kfree(raid_map);
+			btrfs_put_bbio(bbio);
 			return -ENOMEM;
 		}
 
 		atomic_set(&recover->refs, 1);
 		recover->bbio = bbio;
-		recover->raid_map = raid_map;
 		recover->map_length = mapped_length;
 
 		BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO);
 
-		nmirrors = scrub_nr_raid_mirrors(bbio, raid_map);
+		nmirrors = min(scrub_nr_raid_mirrors(bbio), BTRFS_MAX_MIRRORS);
+
 		for (mirror_index = 0; mirror_index < nmirrors;
 		     mirror_index++) {
 			struct scrub_block *sblock;
 			struct scrub_page *page;
 
-			if (mirror_index >= BTRFS_MAX_MIRRORS)
-				continue;
-
 			sblock = sblocks_for_recheck + mirror_index;
 			sblock->sctx = sctx;
 			page = kzalloc(sizeof(*page), GFP_NOFS);
@@ -1410,9 +1389,12 @@ leave_nomem:
 			sblock->pagev[page_index] = page;
 			page->logical = logical;
 
-			scrub_stripe_index_and_offset(logical, raid_map,
+			scrub_stripe_index_and_offset(logical,
+						      bbio->map_type,
+						      bbio->raid_map,
 						      mapped_length,
-						      bbio->num_stripes,
+						      bbio->num_stripes -
+						      bbio->num_tgtdevs,
 						      mirror_index,
 						      &stripe_index,
 						      &stripe_offset);
@@ -1458,7 +1440,8 @@ static void scrub_bio_wait_endio(struct bio *bio, int error)
 
 static inline int scrub_is_page_on_raid56(struct scrub_page *page)
 {
-	return page->recover && page->recover->raid_map;
+	return page->recover &&
+	       (page->recover->bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK);
 }
 
 static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
@@ -1475,7 +1458,6 @@ static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info,
 	bio->bi_end_io = scrub_bio_wait_endio;
 
 	ret = raid56_parity_recover(fs_info->fs_root, bio, page->recover->bbio,
-				    page->recover->raid_map,
 				    page->recover->map_length,
 				    page->mirror_num, 0);
 	if (ret)
@@ -1615,8 +1597,7 @@ static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info,
 }
 
 static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
-					     struct scrub_block *sblock_good,
-					     int force_write)
+					     struct scrub_block *sblock_good)
 {
 	int page_num;
 	int ret = 0;
@@ -1626,8 +1607,7 @@ static int scrub_repair_block_from_good_copy(struct scrub_block *sblock_bad,
 
 		ret_sub = scrub_repair_page_from_good_copy(sblock_bad,
 							   sblock_good,
-							   page_num,
-							   force_write);
+							   page_num, 1);
 		if (ret_sub)
 			ret = ret_sub;
 	}
@@ -2067,12 +2047,12 @@ static int scrub_checksum_super(struct scrub_block *sblock)
 
 static void scrub_block_get(struct scrub_block *sblock)
 {
-	atomic_inc(&sblock->ref_count);
+	atomic_inc(&sblock->refs);
 }
 
 static void scrub_block_put(struct scrub_block *sblock)
 {
-	if (atomic_dec_and_test(&sblock->ref_count)) {
+	if (atomic_dec_and_test(&sblock->refs)) {
 		int i;
 
 		if (sblock->sparity)
@@ -2086,12 +2066,12 @@ static void scrub_block_put(struct scrub_block *sblock)
 
 static void scrub_page_get(struct scrub_page *spage)
 {
-	atomic_inc(&spage->ref_count);
+	atomic_inc(&spage->refs);
 }
 
 static void scrub_page_put(struct scrub_page *spage)
 {
-	if (atomic_dec_and_test(&spage->ref_count)) {
+	if (atomic_dec_and_test(&spage->refs)) {
 		if (spage->page)
 			__free_page(spage->page);
 		kfree(spage);
@@ -2217,7 +2197,7 @@ static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
 
 	/* one ref inside this function, plus one for each page added to
 	 * a bio later on */
-	atomic_set(&sblock->ref_count, 1);
+	atomic_set(&sblock->refs, 1);
 	sblock->sctx = sctx;
 	sblock->no_io_error_seen = 1;
 
@@ -2510,7 +2490,7 @@ static int scrub_pages_for_parity(struct scrub_parity *sparity,
 
 	/* one ref inside this function, plus one for each page added to
 	 * a bio later on */
-	atomic_set(&sblock->ref_count, 1);
+	atomic_set(&sblock->refs, 1);
 	sblock->sctx = sctx;
 	sblock->no_io_error_seen = 1;
 	sblock->sparity = sparity;
@@ -2705,7 +2685,6 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
 	struct btrfs_raid_bio *rbio;
 	struct scrub_page *spage;
 	struct btrfs_bio *bbio = NULL;
-	u64 *raid_map = NULL;
 	u64 length;
 	int ret;
 
@@ -2716,8 +2695,8 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
 	length = sparity->logic_end - sparity->logic_start + 1;
 	ret = btrfs_map_sblock(sctx->dev_root->fs_info, WRITE,
 			       sparity->logic_start,
-			       &length, &bbio, 0, &raid_map);
-	if (ret || !bbio || !raid_map)
+			       &length, &bbio, 0, 1);
+	if (ret || !bbio || !bbio->raid_map)
 		goto bbio_out;
 
 	bio = btrfs_io_bio_alloc(GFP_NOFS, 0);
@@ -2729,8 +2708,7 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
 	bio->bi_end_io = scrub_parity_bio_endio;
 
 	rbio = raid56_parity_alloc_scrub_rbio(sctx->dev_root, bio, bbio,
-					      raid_map, length,
-					      sparity->scrub_dev,
+					      length, sparity->scrub_dev,
 					      sparity->dbitmap,
 					      sparity->nsectors);
 	if (!rbio)
@@ -2747,8 +2725,7 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
 rbio_out:
 	bio_put(bio);
 bbio_out:
-	kfree(bbio);
-	kfree(raid_map);
+	btrfs_put_bbio(bbio);
 	bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap,
 		  sparity->nsectors);
 	spin_lock(&sctx->stat_lock);
@@ -2765,12 +2742,12 @@ static inline int scrub_calc_parity_bitmap_len(int nsectors)
 
 static void scrub_parity_get(struct scrub_parity *sparity)
 {
-	atomic_inc(&sparity->ref_count);
+	atomic_inc(&sparity->refs);
 }
 
 static void scrub_parity_put(struct scrub_parity *sparity)
 {
-	if (!atomic_dec_and_test(&sparity->ref_count))
+	if (!atomic_dec_and_test(&sparity->refs))
 		return;
 
 	scrub_parity_check_and_repair(sparity);
@@ -2820,7 +2797,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
 	sparity->scrub_dev = sdev;
 	sparity->logic_start = logic_start;
 	sparity->logic_end = logic_end;
-	atomic_set(&sparity->ref_count, 1);
+	atomic_set(&sparity->refs, 1);
 	INIT_LIST_HEAD(&sparity->spages);
 	sparity->dbitmap = sparity->bitmap;
 	sparity->ebitmap = (void *)sparity->bitmap + bitmap_len;
@@ -3037,8 +3014,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
 		increment = map->stripe_len;
 		mirror_num = num % map->num_stripes + 1;
-	} else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
-				BTRFS_BLOCK_GROUP_RAID6)) {
+	} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
 		get_raid56_logic_offset(physical, num, map, &offset, NULL);
 		increment = map->stripe_len * nr_data_stripes(map);
 		mirror_num = 1;
@@ -3074,8 +3050,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	 */
 	logical = base + offset;
 	physical_end = physical + nstripes * map->stripe_len;
-	if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
-			 BTRFS_BLOCK_GROUP_RAID6)) {
+	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
 		get_raid56_logic_offset(physical_end, num,
 					map, &logic_end, NULL);
 		logic_end += base;
@@ -3121,8 +3096,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
 	ret = 0;
 	while (physical < physical_end) {
 		/* for raid56, we skip parity stripe */
-		if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
-				BTRFS_BLOCK_GROUP_RAID6)) {
+		if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
 			ret = get_raid56_logic_offset(physical, num,
 					map, &logical, &stripe_logical);
 			logical += base;
@@ -3280,8 +3254,7 @@ again:
 			scrub_free_csums(sctx);
 			if (extent_logical + extent_len <
 			    key.objectid + bytes) {
-				if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
-					BTRFS_BLOCK_GROUP_RAID6)) {
+				if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
 					/*
 					 * loop until we find next data stripe
 					 * or we have finished all stripes.
@@ -3775,7 +3748,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
 	scrub_workers_put(fs_info);
 	mutex_unlock(&fs_info->scrub_lock);
 
-	scrub_free_ctx(sctx);
+	scrub_put_ctx(sctx);
 
 	return ret;
 }
@@ -3881,14 +3854,14 @@ static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
 			      &mapped_length, &bbio, 0);
 	if (ret || !bbio || mapped_length < extent_len ||
 	    !bbio->stripes[0].dev->bdev) {
-		kfree(bbio);
+		btrfs_put_bbio(bbio);
 		return;
 	}
 
 	*extent_physical = bbio->stripes[0].physical;
 	*extent_mirror_num = bbio->mirror_num;
 	*extent_dev = bbio->stripes[0].dev;
-	kfree(bbio);
+	btrfs_put_bbio(bbio);
 }
 
 static int scrub_setup_wr_ctx(struct scrub_ctx *sctx,