Merge tag 'for-6.13-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "Changes outside of btrfs: add io_uring command flag to track a dying
  task (the rest will go via the block git tree).

  User visible changes:

   - wire encoded read (ioctl) to io_uring commands, this can be used on
     itself, in the future this will allow 'send' to be asynchronous. As
     a consequence, the encoded read ioctl can also work in non-blocking
     mode

   - new ioctl to wait for cleaned subvolumes, no need to use the
     generic and root-only SEARCH_TREE ioctl, will be used by "btrfs
     subvol sync"

   - recognize different paths/symlinks for the same devices and don't
     report them during rescanning, this can be observed with LVM or DM

   - seeding device use case change, the sprout device (the one
     capturing new writes) will not clear the read-only status of the
     super block; this prevents accumulating space from deleted
     snapshots

  Performance improvements:

   - reduce lock contention when traversing extent buffers

   - reduce extent tree lock contention when searching for inline
     backref

   - switch from rb-trees to xarray for delayed ref tracking,
     improvements due to better cache locality, branching factors and
     more compact data structures

   - enable extent map shrinker again (prevent memory exhaustion under
     some types of IO load), reworked to run in a single worker thread
     (there used to be problems causing long stalls under memory
     pressure)

  Core changes:

   - raid-stripe-tree feature updates:
       - make device replace and scrub work
       - implement partial deletion of stripe extents
       - new selftests

   - split the config option BTRFS_DEBUG and add EXPERIMENTAL for
     features that are experimental or with known problems so we don't
     misuse debugging config for that

   - subpage mode updates (sector < page):
       - update compression implementations
       - update writepage, writeback

   - continued folio API conversions:
       - buffered writes

   - make buffered write copy one page at a time, preparatory work for
     future integration with large folios, may cause performance drop

   - proper locking of root item regarding starting send

   - error handling improvements

   - code cleanups and refactoring:
       - dead code removal
       - unused parameter reduction
       - lockdep assertions"

* tag 'for-6.13-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (119 commits)
  btrfs: send: check for read-only send root under critical section
  btrfs: send: check for dead send root under critical section
  btrfs: remove check for NULL fs_info at btrfs_folio_end_lock_bitmap()
  btrfs: fix warning on PTR_ERR() against NULL device at btrfs_control_ioctl()
  btrfs: fix a typo in btrfs_use_zone_append
  btrfs: avoid superfluous calls to free_extent_map() in btrfs_encoded_read()
  btrfs: simplify logic to decrement snapshot counter at btrfs_mksnapshot()
  btrfs: remove hole from struct btrfs_delayed_node
  btrfs: update stale comment for struct btrfs_delayed_ref_node::add_list
  btrfs: add new ioctl to wait for cleaned subvolumes
  btrfs: simplify range tracking in cow_file_range()
  btrfs: remove conditional path allocation in btrfs_read_locked_inode()
  btrfs: push cleanup into btrfs_read_locked_inode()
  io_uring/cmd: let cmds to know about dying task
  btrfs: add struct io_btrfs_cmd as type for io_uring_cmd_to_pdu()
  btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)
  btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages()
  btrfs: don't sleep in btrfs_encoded_read() if IOCB_NOWAIT is set
  btrfs: change btrfs_encoded_read() so that reading of extent is done by caller
  btrfs: remove pointless iocb::ki_pos addition in btrfs_encoded_read()
  ...

Author: torvalds

fs/btrfs/Kconfig

@@ -78,6 +78,32 @@ config BTRFS_ASSERT
 
 	  If unsure, say N.
 
+config BTRFS_EXPERIMENTAL
+	bool "Btrfs experimental features"
+	depends on BTRFS_FS
+	default n
+	help
+	  Enable experimental features.  These features may not be stable enough
+	  for end users.  This is meant for btrfs developers or users who wish
+	  to test the functionality and report problems.
+
+	  Current list:
+
+	  - extent map shrinker - performance problems with too frequent shrinks
+
+	  - send stream protocol v3 - fs-verity support
+
+	  - checksum offload mode - sysfs knob to affect when checksums are
+	                            calculated (at IO time, or in a thread)
+
+	  - raid-stripe-tree - additional mapping of extents to devices to
+			       support RAID1* profiles on zoned devices,
+			       RAID56 not yet supported
+
+	  - extent tree v2 - complex rework of extent tracking
+
+	  If unsure, say N.
+
 config BTRFS_FS_REF_VERIFY
 	bool "Btrfs with the ref verify tool compiled in"
 	depends on BTRFS_FS

fs/btrfs/Makefile

@@ -43,4 +43,5 @@ btrfs-$(CONFIG_FS_VERITY) += verity.o
 btrfs-$(CONFIG_BTRFS_FS_RUN_SANITY_TESTS) += tests/free-space-tests.o \
 	tests/extent-buffer-tests.o tests/btrfs-tests.o \
 	tests/extent-io-tests.o tests/inode-tests.o tests/qgroup-tests.o \
-	tests/free-space-tree-tests.o tests/extent-map-tests.o
+	tests/free-space-tree-tests.o tests/extent-map-tests.o \
+	tests/raid-stripe-tree-tests.o

fs/btrfs/backref.c

@@ -1442,7 +1442,8 @@ static int find_parent_nodes(struct btrfs_backref_walk_ctx *ctx,
 		 */
 		delayed_refs = &ctx->trans->transaction->delayed_refs;
 		spin_lock(&delayed_refs->lock);
-		head = btrfs_find_delayed_ref_head(delayed_refs, ctx->bytenr);
+		head = btrfs_find_delayed_ref_head(ctx->fs_info, delayed_refs,
+						   ctx->bytenr);
 		if (head) {
 			if (!mutex_trylock(&head->mutex)) {
 				refcount_inc(&head->refs);

fs/btrfs/bio.c

@@ -587,7 +587,7 @@ static bool should_async_write(struct btrfs_bio *bbio)
 {
 	bool auto_csum_mode = true;
 
-#ifdef CONFIG_BTRFS_DEBUG
+#ifdef CONFIG_BTRFS_EXPERIMENTAL
 	struct btrfs_fs_devices *fs_devices = bbio->fs_info->fs_devices;
 	enum btrfs_offload_csum_mode csum_mode = READ_ONCE(fs_devices->offload_csum_mode);
 

fs/btrfs/block-group.c

@@ -2797,7 +2797,7 @@ void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans)
 		 * uncompressed data size, because the compression is only done
 		 * when writeback triggered and we don't know how much space we
 		 * are actually going to need, so we reserve the uncompressed
-		 * size because the data may be uncompressible in the worst case.
+		 * size because the data may be incompressible in the worst case.
 		 */
 		if (ret == 0) {
 			bool used;

fs/btrfs/btrfs_inode.h

@@ -577,7 +577,6 @@ void btrfs_merge_delalloc_extent(struct btrfs_inode *inode, struct extent_state
 				 struct extent_state *other);
 void btrfs_split_delalloc_extent(struct btrfs_inode *inode,
 				 struct extent_state *orig, u64 split);
-void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end);
 void btrfs_evict_inode(struct inode *inode);
 struct inode *btrfs_alloc_inode(struct super_block *sb);
 void btrfs_destroy_inode(struct inode *inode);
@@ -613,11 +612,17 @@ int btrfs_writepage_cow_fixup(struct folio *folio);
 int btrfs_encoded_io_compression_from_extent(struct btrfs_fs_info *fs_info,
 					     int compress_type);
 int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
-					  u64 file_offset, u64 disk_bytenr,
-					  u64 disk_io_size,
-					  struct page **pages);
+					  u64 disk_bytenr, u64 disk_io_size,
+					  struct page **pages, void *uring_ctx);
 ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
-			   struct btrfs_ioctl_encoded_io_args *encoded);
+			   struct btrfs_ioctl_encoded_io_args *encoded,
+			   struct extent_state **cached_state,
+			   u64 *disk_bytenr, u64 *disk_io_size);
+ssize_t btrfs_encoded_read_regular(struct kiocb *iocb, struct iov_iter *iter,
+				   u64 start, u64 lockend,
+				   struct extent_state **cached_state,
+				   u64 disk_bytenr, u64 disk_io_size,
+				   size_t count, bool compressed, bool *unlocked);
 ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
 			       const struct btrfs_ioctl_encoded_io_args *encoded);
 

fs/btrfs/compression.c

@@ -453,7 +453,7 @@ static noinline int add_ra_bio_pages(struct inode *inode,
 		if (pg_index > end_index)
 			break;
 
-		folio = __filemap_get_folio(mapping, pg_index, 0, 0);
+		folio = filemap_get_folio(mapping, pg_index);
 		if (!IS_ERR(folio)) {
 			u64 folio_sz = folio_size(folio);
 			u64 offset = offset_in_folio(folio, cur);
@@ -545,8 +545,7 @@ static noinline int add_ra_bio_pages(struct inode *inode,
 		 * subpage::readers and to unlock the page.
 		 */
 		if (fs_info->sectorsize < PAGE_SIZE)
-			btrfs_subpage_start_reader(fs_info, folio, cur,
-						   add_size);
+			btrfs_folio_set_lock(fs_info, folio, cur, add_size);
 		folio_put(folio);
 		cur += add_size;
 	}
@@ -702,7 +701,7 @@ static void free_heuristic_ws(struct list_head *ws)
 	kfree(workspace);
 }
 
-static struct list_head *alloc_heuristic_ws(unsigned int level)
+static struct list_head *alloc_heuristic_ws(void)
 {
 	struct heuristic_ws *ws;
 
@@ -744,9 +743,9 @@ static const struct btrfs_compress_op * const btrfs_compress_op[] = {
 static struct list_head *alloc_workspace(int type, unsigned int level)
 {
 	switch (type) {
-	case BTRFS_COMPRESS_NONE: return alloc_heuristic_ws(level);
+	case BTRFS_COMPRESS_NONE: return alloc_heuristic_ws();
 	case BTRFS_COMPRESS_ZLIB: return zlib_alloc_workspace(level);
-	case BTRFS_COMPRESS_LZO:  return lzo_alloc_workspace(level);
+	case BTRFS_COMPRESS_LZO:  return lzo_alloc_workspace();
 	case BTRFS_COMPRESS_ZSTD: return zstd_alloc_workspace(level);
 	default:
 		/*
@@ -1030,13 +1029,16 @@ int btrfs_compress_folios(unsigned int type_level, struct address_space *mapping
 {
 	int type = btrfs_compress_type(type_level);
 	int level = btrfs_compress_level(type_level);
+	const unsigned long orig_len = *total_out;
 	struct list_head *workspace;
 	int ret;
 
 	level = btrfs_compress_set_level(type, level);
 	workspace = get_workspace(type, level);
 	ret = compression_compress_pages(type, workspace, mapping, start, folios,
 					 out_folios, total_in, total_out);
+	/* The total read-in bytes should be no larger than the input. */
+	ASSERT(*total_in <= orig_len);
 	put_workspace(type, workspace);
 	return ret;
 }

fs/btrfs/compression.h

@@ -175,7 +175,7 @@ int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
 int lzo_decompress(struct list_head *ws, const u8 *data_in,
 		struct folio *dest_folio, unsigned long dest_pgoff, size_t srclen,
 		size_t destlen);
-struct list_head *lzo_alloc_workspace(unsigned int level);
+struct list_head *lzo_alloc_workspace(void);
 void lzo_free_workspace(struct list_head *ws);
 
 int zstd_compress_folios(struct list_head *ws, struct address_space *mapping,

fs/btrfs/ctree.c

@@ -1508,26 +1508,26 @@ static noinline void unlock_up(struct btrfs_path *path, int level,
  */
 static int
 read_block_for_search(struct btrfs_root *root, struct btrfs_path *p,
-		      struct extent_buffer **eb_ret, int level, int slot,
+		      struct extent_buffer **eb_ret, int slot,
 		      const struct btrfs_key *key)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_tree_parent_check check = { 0 };
 	u64 blocknr;
-	u64 gen;
-	struct extent_buffer *tmp;
-	int ret;
+	struct extent_buffer *tmp = NULL;
+	int ret = 0;
 	int parent_level;
-	bool unlock_up;
+	int err;
+	bool read_tmp = false;
+	bool tmp_locked = false;
+	bool path_released = false;
 
-	unlock_up = ((level + 1 < BTRFS_MAX_LEVEL) && p->locks[level + 1]);
 	blocknr = btrfs_node_blockptr(*eb_ret, slot);
-	gen = btrfs_node_ptr_generation(*eb_ret, slot);
 	parent_level = btrfs_header_level(*eb_ret);
 	btrfs_node_key_to_cpu(*eb_ret, &check.first_key, slot);
 	check.has_first_key = true;
 	check.level = parent_level - 1;
-	check.transid = gen;
+	check.transid = btrfs_node_ptr_generation(*eb_ret, slot);
 	check.owner_root = btrfs_root_id(root);
 
 	/*
@@ -1540,79 +1540,115 @@ read_block_for_search(struct btrfs_root *root, struct btrfs_path *p,
 	tmp = find_extent_buffer(fs_info, blocknr);
 	if (tmp) {
 		if (p->reada == READA_FORWARD_ALWAYS)
-			reada_for_search(fs_info, p, level, slot, key->objectid);
+			reada_for_search(fs_info, p, parent_level, slot, key->objectid);
 
 		/* first we do an atomic uptodate check */
-		if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) {
+		if (btrfs_buffer_uptodate(tmp, check.transid, 1) > 0) {
 			/*
 			 * Do extra check for first_key, eb can be stale due to
 			 * being cached, read from scrub, or have multiple
 			 * parents (shared tree blocks).
 			 */
-			if (btrfs_verify_level_key(tmp,
-					parent_level - 1, &check.first_key, gen)) {
-				free_extent_buffer(tmp);
-				return -EUCLEAN;
+			if (btrfs_verify_level_key(tmp, &check)) {
+				ret = -EUCLEAN;
+				goto out;
 			}
 			*eb_ret = tmp;
-			return 0;
+			tmp = NULL;
+			ret = 0;
+			goto out;
 		}
 
 		if (p->nowait) {
-			free_extent_buffer(tmp);
-			return -EAGAIN;
+			ret = -EAGAIN;
+			goto out;
 		}
 
-		if (unlock_up)
-			btrfs_unlock_up_safe(p, level + 1);
-
-		/* now we're allowed to do a blocking uptodate check */
-		ret = btrfs_read_extent_buffer(tmp, &check);
-		if (ret) {
-			free_extent_buffer(tmp);
+		if (!p->skip_locking) {
+			btrfs_unlock_up_safe(p, parent_level + 1);
+			tmp_locked = true;
+			btrfs_tree_read_lock(tmp);
 			btrfs_release_path(p);
-			return ret;
+			ret = -EAGAIN;
+			path_released = true;
 		}
 
-		if (unlock_up)
-			ret = -EAGAIN;
+		/* Now we're allowed to do a blocking uptodate check. */
+		err = btrfs_read_extent_buffer(tmp, &check);
+		if (err) {
+			ret = err;
+			goto out;
+		}
 
+		if (ret == 0) {
+			ASSERT(!tmp_locked);
+			*eb_ret = tmp;
+			tmp = NULL;
+		}
 		goto out;
 	} else if (p->nowait) {
-		return -EAGAIN;
+		ret = -EAGAIN;
+		goto out;
 	}
 
-	if (unlock_up) {
-		btrfs_unlock_up_safe(p, level + 1);
+	if (!p->skip_locking) {
+		btrfs_unlock_up_safe(p, parent_level + 1);
 		ret = -EAGAIN;
-	} else {
-		ret = 0;
 	}
 
 	if (p->reada != READA_NONE)
-		reada_for_search(fs_info, p, level, slot, key->objectid);
+		reada_for_search(fs_info, p, parent_level, slot, key->objectid);
 
-	tmp = read_tree_block(fs_info, blocknr, &check);
+	tmp = btrfs_find_create_tree_block(fs_info, blocknr, check.owner_root, check.level);
 	if (IS_ERR(tmp)) {
+		ret = PTR_ERR(tmp);
+		tmp = NULL;
+		goto out;
+	}
+	read_tmp = true;
+
+	if (!p->skip_locking) {
+		ASSERT(ret == -EAGAIN);
+		tmp_locked = true;
+		btrfs_tree_read_lock(tmp);
 		btrfs_release_path(p);
-		return PTR_ERR(tmp);
+		path_released = true;
+	}
+
+	/* Now we're allowed to do a blocking uptodate check. */
+	err = btrfs_read_extent_buffer(tmp, &check);
+	if (err) {
+		ret = err;
+		goto out;
 	}
+
 	/*
 	 * If the read above didn't mark this buffer up to date,
 	 * it will never end up being up to date.  Set ret to EIO now
 	 * and give up so that our caller doesn't loop forever
 	 * on our EAGAINs.
 	 */
-	if (!extent_buffer_uptodate(tmp))
+	if (!extent_buffer_uptodate(tmp)) {
 		ret = -EIO;
+		goto out;
+	}
 
-out:
 	if (ret == 0) {
+		ASSERT(!tmp_locked);
 		*eb_ret = tmp;
-	} else {
-		free_extent_buffer(tmp);
-		btrfs_release_path(p);
+		tmp = NULL;
+	}
+out:
+	if (tmp) {
+		if (tmp_locked)
+			btrfs_tree_read_unlock(tmp);
+		if (read_tmp && ret && ret != -EAGAIN)
+			free_extent_buffer_stale(tmp);
+		else
+			free_extent_buffer(tmp);
 	}
+	if (ret && !path_released)
+		btrfs_release_path(p);
 
 	return ret;
 }
@@ -2197,8 +2233,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 			goto done;
 		}
 
-		err = read_block_for_search(root, p, &b, level, slot, key);
-		if (err == -EAGAIN)
+		err = read_block_for_search(root, p, &b, slot, key);
+		if (err == -EAGAIN && !p->nowait)
 			goto again;
 		if (err) {
 			ret = err;
@@ -2324,8 +2360,8 @@ int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
 			goto done;
 		}
 
-		err = read_block_for_search(root, p, &b, level, slot, key);
-		if (err == -EAGAIN)
+		err = read_block_for_search(root, p, &b, slot, key);
+		if (err == -EAGAIN && !p->nowait)
 			goto again;
 		if (err) {
 			ret = err;
@@ -2334,7 +2370,7 @@ int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
 
 		level = btrfs_header_level(b);
 		btrfs_tree_read_lock(b);
-		b = btrfs_tree_mod_log_rewind(fs_info, p, b, time_seq);
+		b = btrfs_tree_mod_log_rewind(fs_info, b, time_seq);
 		if (!b) {
 			ret = -ENOMEM;
 			goto done;
@@ -4930,8 +4966,7 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
 		}
 
 		next = c;
-		ret = read_block_for_search(root, path, &next, level,
-					    slot, &key);
+		ret = read_block_for_search(root, path, &next, slot, &key);
 		if (ret == -EAGAIN && !path->nowait)
 			goto again;
 
@@ -4974,8 +5009,7 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
 		if (!level)
 			break;
 
-		ret = read_block_for_search(root, path, &next, level,
-					    0, &key);
+		ret = read_block_for_search(root, path, &next, 0, &key);
 		if (ret == -EAGAIN && !path->nowait)
 			goto again;