treewide: refresh kmalloc_obj() conversionsgrafted

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>

1 files changed, 746 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
new file mode 100644
index 000000000..22ba2b450
--- /dev/null
+++ b/fs/btrfs/ctree.h
@@ -0,0 +1,746 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ */
+
+#ifndef BTRFS_CTREE_H
+#define BTRFS_CTREE_H
+
+#include <linux/cleanup.h>
+#include <linux/spinlock.h>
+#include <linux/rbtree.h>
+#include <linux/mutex.h>
+#include <linux/wait.h>
+#include <linux/list.h>
+#include <linux/atomic.h>
+#include <linux/xarray.h>
+#include <linux/refcount.h>
+#include <uapi/linux/btrfs_tree.h>
+#include "locking.h"
+#include "accessors.h"
+
+struct extent_buffer;
+struct btrfs_block_rsv;
+struct btrfs_trans_handle;
+struct btrfs_block_group;
+
+/* Read ahead values for struct btrfs_path.reada */
+enum {
+	READA_NONE,
+	READA_BACK,
+	READA_FORWARD,
+	/*
+	 * Similar to READA_FORWARD but unlike it:
+	 *
+	 * 1) It will trigger readahead even for leaves that are not close to
+	 *    each other on disk;
+	 * 2) It also triggers readahead for nodes;
+	 * 3) During a search, even when a node or leaf is already in memory, it
+	 *    will still trigger readahead for other nodes and leaves that follow
+	 *    it.
+	 *
+	 * This is meant to be used only when we know we are iterating over the
+	 * entire tree or a very large part of it.
+	 */
+	READA_FORWARD_ALWAYS,
+};
+
+/*
+ * btrfs_paths remember the path taken from the root down to the leaf.
+ * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
+ * to any other levels that are present.
+ *
+ * The slots array records the index of the item or block pointer
+ * used while walking the tree.
+ */
+struct btrfs_path {
+	struct extent_buffer *nodes[BTRFS_MAX_LEVEL];
+	int slots[BTRFS_MAX_LEVEL];
+	/* if there is real range locking, this locks field will change */
+	u8 locks[BTRFS_MAX_LEVEL];
+	u8 reada;
+	u8 lowest_level;
+
+	/*
+	 * set by btrfs_split_item, tells search_slot to keep all locks
+	 * and to force calls to keep space in the nodes
+	 */
+	bool search_for_split:1;
+	/* Keep some upper locks as we walk down. */
+	bool keep_locks:1;
+	bool skip_locking:1;
+	bool search_commit_root:1;
+	bool need_commit_sem:1;
+	bool skip_release_on_error:1;
+	/*
+	 * Indicate that new item (btrfs_search_slot) is extending already
+	 * existing item and ins_len contains only the data size and not item
+	 * header (ie. sizeof(struct btrfs_item) is not included).
+	 */
+	bool search_for_extension:1;
+	/* Stop search if any locks need to be taken (for read) */
+	bool nowait:1;
+};
+
+#define BTRFS_PATH_AUTO_FREE(path_name)					\
+	struct btrfs_path *path_name __free(btrfs_free_path) = NULL
+
+/*
+ * This defines an on-stack path that will be auto released when exiting the scope.
+ *
+ * It is compatible with any existing manual btrfs_release_path() calls.
+ */
+#define BTRFS_PATH_AUTO_RELEASE(path_name)					\
+	struct btrfs_path path_name __free(btrfs_release_path) = { 0 }
+
+/*
+ * The state of btrfs root
+ */
+enum {
+	/*
+	 * btrfs_record_root_in_trans is a multi-step process, and it can race
+	 * with the balancing code.   But the race is very small, and only the
+	 * first time the root is added to each transaction.  So IN_TRANS_SETUP
+	 * is used to tell us when more checks are required
+	 */
+	BTRFS_ROOT_IN_TRANS_SETUP,
+
+	/*
+	 * Set if tree blocks of this root can be shared by other roots.
+	 * Only subvolume trees and their reloc trees have this bit set.
+	 * Conflicts with TRACK_DIRTY bit.
+	 *
+	 * This affects two things:
+	 *
+	 * - How balance works
+	 *   For shareable roots, we need to use reloc tree and do path
+	 *   replacement for balance, and need various pre/post hooks for
+	 *   snapshot creation to handle them.
+	 *
+	 *   While for non-shareable trees, we just simply do a tree search
+	 *   with COW.
+	 *
+	 * - How dirty roots are tracked
+	 *   For shareable roots, btrfs_record_root_in_trans() is needed to
+	 *   track them, while non-subvolume roots have TRACK_DIRTY bit, they
+	 *   don't need to set this manually.
+	 */
+	BTRFS_ROOT_SHAREABLE,
+	BTRFS_ROOT_TRACK_DIRTY,
+	BTRFS_ROOT_IN_RADIX,
+	BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
+	BTRFS_ROOT_DEFRAG_RUNNING,
+	BTRFS_ROOT_FORCE_COW,
+	BTRFS_ROOT_DIRTY,
+	BTRFS_ROOT_DELETING,
+
+	/*
+	 * Reloc tree is orphan, only kept here for qgroup delayed subtree scan
+	 *
+	 * Set for the subvolume tree owning the reloc tree.
+	 */
+	BTRFS_ROOT_DEAD_RELOC_TREE,
+	/* Mark dead root stored on device whose cleanup needs to be resumed */
+	BTRFS_ROOT_DEAD_TREE,
+	/* The root has a log tree. Used for subvolume roots and the tree root. */
+	BTRFS_ROOT_HAS_LOG_TREE,
+	/* Qgroup flushing is in progress */
+	BTRFS_ROOT_QGROUP_FLUSHING,
+	/* We started the orphan cleanup for this root. */
+	BTRFS_ROOT_ORPHAN_CLEANUP,
+	/* This root has a drop operation that was started previously. */
+	BTRFS_ROOT_UNFINISHED_DROP,
+	/* This reloc root needs to have its buffers lockdep class reset. */
+	BTRFS_ROOT_RESET_LOCKDEP_CLASS,
+};
+
+/*
+ * Record swapped tree blocks of a subvolume tree for delayed subtree trace
+ * code. For detail check comment in fs/btrfs/qgroup.c.
+ */
+struct btrfs_qgroup_swapped_blocks {
+	spinlock_t lock;
+	/* RM_EMPTY_ROOT() of above blocks[] */
+	bool swapped;
+	struct rb_root blocks[BTRFS_MAX_LEVEL];
+};
+
+/*
+ * in ram representation of the tree.  extent_root is used for all allocations
+ * and for the extent tree extent_root root.
+ */
+struct btrfs_root {
+	struct rb_node rb_node;
+
+	struct extent_buffer *node;
+
+	struct extent_buffer *commit_root;
+	struct btrfs_root *log_root;
+	struct btrfs_root *reloc_root;
+
+	unsigned long state;
+	struct btrfs_root_item root_item;
+	struct btrfs_key root_key;
+	struct btrfs_fs_info *fs_info;
+	struct extent_io_tree dirty_log_pages;
+
+	struct mutex objectid_mutex;
+
+	spinlock_t accounting_lock;
+	struct btrfs_block_rsv *block_rsv;
+
+	struct mutex log_mutex;
+	wait_queue_head_t log_writer_wait;
+	wait_queue_head_t log_commit_wait[2];
+	struct list_head log_ctxs[2];
+	/* Used only for log trees of subvolumes, not for the log root tree */
+	atomic_t log_writers;
+	bool log_commit[2];
+	/*
+	 * Protected by the 'log_mutex' lock but can be read without holding
+	 * that lock to avoid unnecessary lock contention, in which case it
+	 * should be read using btrfs_get_root_log_transid() except if it's a
+	 * log tree in which case it can be directly accessed. Updates to this
+	 * field should always use btrfs_set_root_log_transid(), except for log
+	 * trees where the field can be updated directly.
+	 */
+	int log_transid;
+	/* No matter the commit succeeds or not*/
+	int log_transid_committed;
+	/*
+	 * Just be updated when the commit succeeds. Use
+	 * btrfs_get_root_last_log_commit() and btrfs_set_root_last_log_commit()
+	 * to access this field.
+	 */
+	int last_log_commit;
+
+	u64 last_trans;
+
+	u64 free_objectid;
+
+	struct btrfs_key defrag_progress;
+	struct btrfs_key defrag_max;
+
+	/* The dirty list is only used by non-shareable roots */
+	struct list_head dirty_list;
+
+	struct list_head root_list;
+
+	/* Xarray that keeps track of in-memory inodes. */
+	struct xarray inodes;
+
+	/* Xarray that keeps track of delayed nodes of every inode. */
+	struct xarray delayed_nodes;
+	/*
+	 * right now this just gets used so that a root has its own devid
+	 * for stat.  It may be used for more later
+	 */
+	dev_t anon_dev;
+
+	spinlock_t root_item_lock;
+	refcount_t refs;
+
+	struct mutex delalloc_mutex;
+	spinlock_t delalloc_lock;
+	/*
+	 * all of the inodes that have delalloc bytes.  It is possible for
+	 * this list to be empty even when there is still dirty data=ordered
+	 * extents waiting to finish IO.
+	 */
+	struct list_head delalloc_inodes;
+	struct list_head delalloc_root;
+	u64 nr_delalloc_inodes;
+
+	struct mutex ordered_extent_mutex;
+	/*
+	 * this is used by the balancing code to wait for all the pending
+	 * ordered extents
+	 */
+	spinlock_t ordered_extent_lock;
+
+	/*
+	 * all of the data=ordered extents pending writeback
+	 * these can span multiple transactions and basically include
+	 * every dirty data page that isn't from nodatacow
+	 */
+	struct list_head ordered_extents;
+	struct list_head ordered_root;
+	u64 nr_ordered_extents;
+
+	/*
+	 * Not empty if this subvolume root has gone through tree block swap
+	 * (relocation)
+	 *
+	 * Will be used by reloc_control::dirty_subvol_roots.
+	 */
+	struct list_head reloc_dirty_list;
+
+	/*
+	 * Number of currently running SEND ioctls to prevent
+	 * manipulation with the read-only status via SUBVOL_SETFLAGS
+	 */
+	int send_in_progress;
+	/*
+	 * Number of currently running deduplication operations that have a
+	 * destination inode belonging to this root. Protected by the lock
+	 * root_item_lock.
+	 */
+	int dedupe_in_progress;
+	/* For exclusion of snapshot creation and nocow writes */
+	struct btrfs_drew_lock snapshot_lock;
+
+	atomic_t snapshot_force_cow;
+
+	/* For qgroup metadata reserved space */
+	spinlock_t qgroup_meta_rsv_lock;
+	u64 qgroup_meta_rsv_pertrans;
+	u64 qgroup_meta_rsv_prealloc;
+	wait_queue_head_t qgroup_flush_wait;
+
+	/* Number of active swapfiles */
+	atomic_t nr_swapfiles;
+
+	/* Record pairs of swapped blocks for qgroup */
+	struct btrfs_qgroup_swapped_blocks swapped_blocks;
+
+	/* Used only by log trees, when logging csum items */
+	struct extent_io_tree log_csum_range;
+
+	/* Used in simple quotas, track root during relocation. */
+	u64 relocation_src_root;
+
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+	u64 alloc_bytenr;
+#endif
+
+#ifdef CONFIG_BTRFS_DEBUG
+	struct list_head leak_list;
+#endif
+};
+
+static inline bool btrfs_root_readonly(const struct btrfs_root *root)
+{
+	/* Byte-swap the constant at compile time, root_item::flags is LE */
+	return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0;
+}
+
+static inline bool btrfs_root_dead(const struct btrfs_root *root)
+{
+	/* Byte-swap the constant at compile time, root_item::flags is LE */
+	return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_DEAD)) != 0;
+}
+
+static inline u64 btrfs_root_id(const struct btrfs_root *root)
+{
+	return root->root_key.objectid;
+}
+
+static inline int btrfs_get_root_log_transid(const struct btrfs_root *root)
+{
+	return READ_ONCE(root->log_transid);
+}
+
+static inline void btrfs_set_root_log_transid(struct btrfs_root *root, int log_transid)
+{
+	WRITE_ONCE(root->log_transid, log_transid);
+}
+
+static inline int btrfs_get_root_last_log_commit(const struct btrfs_root *root)
+{
+	return READ_ONCE(root->last_log_commit);
+}
+
+static inline void btrfs_set_root_last_log_commit(struct btrfs_root *root, int commit_id)
+{
+	WRITE_ONCE(root->last_log_commit, commit_id);
+}
+
+static inline u64 btrfs_get_root_last_trans(const struct btrfs_root *root)
+{
+	return READ_ONCE(root->last_trans);
+}
+
+static inline void btrfs_set_root_last_trans(struct btrfs_root *root, u64 transid)
+{
+	WRITE_ONCE(root->last_trans, transid);
+}
+
+/*
+ * Return the generation this root started with.
+ *
+ * Every normal root that is created with root->root_key.offset set to it's
+ * originating generation.  If it is a snapshot it is the generation when the
+ * snapshot was created.
+ *
+ * However for TREE_RELOC roots root_key.offset is the objectid of the owning
+ * tree root.  Thankfully we copy the root item of the owning tree root, which
+ * has it's last_snapshot set to what we would have root_key.offset set to, so
+ * return that if this is a TREE_RELOC root.
+ */
+static inline u64 btrfs_root_origin_generation(const struct btrfs_root *root)
+{
+	if (btrfs_root_id(root) == BTRFS_TREE_RELOC_OBJECTID)
+		return btrfs_root_last_snapshot(&root->root_item);
+	return root->root_key.offset;
+}
+
+/*
+ * Structure that conveys information about an extent that is going to replace
+ * all the extents in a file range.
+ */
+struct btrfs_replace_extent_info {
+	u64 disk_offset;
+	u64 disk_len;
+	u64 data_offset;
+	u64 data_len;
+	u64 file_offset;
+	/* Pointer to a file extent item of type regular or prealloc. */
+	char *extent_buf;
+	/*
+	 * Set to true when attempting to replace a file range with a new extent
+	 * described by this structure, set to false when attempting to clone an
+	 * existing extent into a file range.
+	 */
+	bool is_new_extent;
+	/* Indicate if we should update the inode's mtime and ctime. */
+	bool update_times;
+	/* Meaningful only if is_new_extent is true. */
+	int qgroup_reserved;
+	/*
+	 * Meaningful only if is_new_extent is true.
+	 * Used to track how many extent items we have already inserted in a
+	 * subvolume tree that refer to the extent described by this structure,
+	 * so that we know when to create a new delayed ref or update an existing
+	 * one.
+	 */
+	int insertions;
+};
+
+/* Arguments for btrfs_drop_extents() */
+struct btrfs_drop_extents_args {
+	/* Input parameters */
+
+	/*
+	 * If NULL, btrfs_drop_extents() will allocate and free its own path.
+	 * If 'replace_extent' is true, this must not be NULL. Also the path
+	 * is always released except if 'replace_extent' is true and
+	 * btrfs_drop_extents() sets 'extent_inserted' to true, in which case
+	 * the path is kept locked.
+	 */
+	struct btrfs_path *path;
+	/* Start offset of the range to drop extents from */
+	u64 start;
+	/* End (exclusive, last byte + 1) of the range to drop extents from */
+	u64 end;
+	/* If true drop all the extent maps in the range */
+	bool drop_cache;
+	/*
+	 * If true it means we want to insert a new extent after dropping all
+	 * the extents in the range. If this is true, the 'extent_item_size'
+	 * parameter must be set as well and the 'extent_inserted' field will
+	 * be set to true by btrfs_drop_extents() if it could insert the new
+	 * extent.
+	 * Note: when this is set to true the path must not be NULL.
+	 */
+	bool replace_extent;
+	/*
+	 * Used if 'replace_extent' is true. Size of the file extent item to
+	 * insert after dropping all existing extents in the range
+	 */
+	u32 extent_item_size;
+
+	/* Output parameters */
+
+	/*
+	 * Set to the minimum between the input parameter 'end' and the end
+	 * (exclusive, last byte + 1) of the last dropped extent. This is always
+	 * set even if btrfs_drop_extents() returns an error.
+	 */
+	u64 drop_end;
+	/*
+	 * The number of allocated bytes found in the range. This can be smaller
+	 * than the range's length when there are holes in the range.
+	 */
+	u64 bytes_found;
+	/*
+	 * Only set if 'replace_extent' is true. Set to true if we were able
+	 * to insert a replacement extent after dropping all extents in the
+	 * range, otherwise set to false by btrfs_drop_extents().
+	 * Also, if btrfs_drop_extents() has set this to true it means it
+	 * returned with the path locked, otherwise if it has set this to
+	 * false it has returned with the path released.
+	 */
+	bool extent_inserted;
+};
+
+struct btrfs_file_private {
+	void *filldir_buf;
+	u64 last_index;
+	struct extent_state *llseek_cached_state;
+	/* Task that allocated this structure. */
+	struct task_struct *owner_task;
+};
+
+static inline u32 BTRFS_LEAF_DATA_SIZE(const struct btrfs_fs_info *info)
+{
+	return info->nodesize - sizeof(struct btrfs_header);
+}
+
+static inline u32 BTRFS_MAX_ITEM_SIZE(const struct btrfs_fs_info *info)
+{
+	return BTRFS_LEAF_DATA_SIZE(info) - sizeof(struct btrfs_item);
+}
+
+static inline u32 BTRFS_NODEPTRS_PER_BLOCK(const struct btrfs_fs_info *info)
+{
+	return BTRFS_LEAF_DATA_SIZE(info) / sizeof(struct btrfs_key_ptr);
+}
+
+static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info)
+{
+	return BTRFS_MAX_ITEM_SIZE(info) - sizeof(struct btrfs_dir_item);
+}
+
+int __init btrfs_ctree_init(void);
+void __cold btrfs_ctree_exit(void);
+
+int btrfs_bin_search(const struct extent_buffer *eb, int first_slot,
+		     const struct btrfs_key *key, int *slot);
+
+int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
+
+#ifdef __LITTLE_ENDIAN
+
+/*
+ * Compare two keys, on little-endian the disk order is same as CPU order and
+ * we can avoid the conversion.
+ */
+static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk_key,
+				  const struct btrfs_key *k2)
+{
+	const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key;
+
+	return btrfs_comp_cpu_keys(k1, k2);
+}
+
+#else
+
+/* Compare two keys in a memcmp fashion. */
+static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk,
+				  const struct btrfs_key *k2)
+{
+	struct btrfs_key k1;
+
+	btrfs_disk_key_to_cpu(&k1, disk);
+
+	return btrfs_comp_cpu_keys(&k1, k2);
+}
+
+#endif
+
+int btrfs_previous_item(struct btrfs_root *root,
+			struct btrfs_path *path, u64 min_objectid,
+			int type);
+int btrfs_previous_extent_item(struct btrfs_root *root,
+			struct btrfs_path *path, u64 min_objectid);
+void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
+			     const struct btrfs_path *path,
+			     const struct btrfs_key *new_key);
+struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
+int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
+			struct btrfs_key *key, int lowest_level,
+			u64 min_trans);
+int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
+			 struct btrfs_path *path,
+			 u64 min_trans);
+struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
+					   int slot);
+
+int btrfs_cow_block(struct btrfs_trans_handle *trans,
+		    struct btrfs_root *root, struct extent_buffer *buf,
+		    struct extent_buffer *parent, int parent_slot,
+		    struct extent_buffer **cow_ret,
+		    enum btrfs_lock_nesting nest);
+int btrfs_force_cow_block(struct btrfs_trans_handle *trans,
+			  struct btrfs_root *root,
+			  struct extent_buffer *buf,
+			  struct extent_buffer *parent, int parent_slot,
+			  struct extent_buffer **cow_ret,
+			  u64 search_start, u64 empty_size,
+			  enum btrfs_lock_nesting nest);
+int btrfs_copy_root(struct btrfs_trans_handle *trans,
+		      struct btrfs_root *root,
+		      struct extent_buffer *buf,
+		      struct extent_buffer **cow_ret, u64 new_root_objectid);
+bool btrfs_block_can_be_shared(const struct btrfs_trans_handle *trans,
+			       const struct btrfs_root *root,
+			       const struct extent_buffer *buf);
+int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		  struct btrfs_path *path, int level, int slot);
+void btrfs_extend_item(struct btrfs_trans_handle *trans,
+		       const struct btrfs_path *path, u32 data_size);
+void btrfs_truncate_item(struct btrfs_trans_handle *trans,
+			 const struct btrfs_path *path, u32 new_size, int from_end);
+int btrfs_split_item(struct btrfs_trans_handle *trans,
+		     struct btrfs_root *root,
+		     struct btrfs_path *path,
+		     const struct btrfs_key *new_key,
+		     unsigned long split_offset);
+int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
+			 struct btrfs_root *root,
+			 struct btrfs_path *path,
+			 const struct btrfs_key *new_key);
+int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path,
+		u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key);
+int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		      const struct btrfs_key *key, struct btrfs_path *p,
+		      int ins_len, int cow);
+int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
+			  struct btrfs_path *p, u64 time_seq);
+int btrfs_search_slot_for_read(struct btrfs_root *root,
+			       const struct btrfs_key *key,
+			       struct btrfs_path *p, int find_higher,
+			       int return_any);
+void btrfs_release_path(struct btrfs_path *p);
+struct btrfs_path *btrfs_alloc_path(void);
+void btrfs_free_path(struct btrfs_path *p);
+DEFINE_FREE(btrfs_free_path, struct btrfs_path *, btrfs_free_path(_T))
+DEFINE_FREE(btrfs_release_path, struct btrfs_path, btrfs_release_path(&_T))
+
+int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		   struct btrfs_path *path, int slot, int nr);
+static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
+				 struct btrfs_root *root,
+				 struct btrfs_path *path)
+{
+	return btrfs_del_items(trans, root, path, path->slots[0], 1);
+}
+
+/*
+ * Describes a batch of items to insert in a btree. This is used by
+ * btrfs_insert_empty_items().
+ */
+struct btrfs_item_batch {
+	/*
+	 * Pointer to an array containing the keys of the items to insert (in
+	 * sorted order).
+	 */
+	const struct btrfs_key *keys;
+	/* Pointer to an array containing the data size for each item to insert. */
+	const u32 *data_sizes;
+	/*
+	 * The sum of data sizes for all items. The caller can compute this while
+	 * setting up the data_sizes array, so it ends up being more efficient
+	 * than having btrfs_insert_empty_items() or setup_item_for_insert()
+	 * doing it, as it would avoid an extra loop over a potentially large
+	 * array, and in the case of setup_item_for_insert(), we would be doing
+	 * it while holding a write lock on a leaf and often on upper level nodes
+	 * too, unnecessarily increasing the size of a critical section.
+	 */
+	u32 total_data_size;
+	/* Size of the keys and data_sizes arrays (number of items in the batch). */
+	int nr;
+};
+
+void btrfs_setup_item_for_insert(struct btrfs_trans_handle *trans,
+				 struct btrfs_root *root,
+				 struct btrfs_path *path,
+				 const struct btrfs_key *key,
+				 u32 data_size);
+int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+		      const struct btrfs_key *key, void *data, u32 data_size);
+int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
+			     struct btrfs_root *root,
+			     struct btrfs_path *path,
+			     const struct btrfs_item_batch *batch);
+
+static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
+					  struct btrfs_root *root,
+					  struct btrfs_path *path,
+					  const struct btrfs_key *key,
+					  u32 data_size)
+{
+	struct btrfs_item_batch batch;
+
+	batch.keys = key;
+	batch.data_sizes = &data_size;
+	batch.total_data_size = data_size;
+	batch.nr = 1;
+
+	return btrfs_insert_empty_items(trans, root, path, &batch);
+}
+
+int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
+			u64 time_seq);
+
+int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
+			   struct btrfs_path *path);
+
+int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
+			      struct btrfs_path *path);
+
+/*
+ * Search in @root for a given @key, and store the slot found in @found_key.
+ *
+ * @root:	The root node of the tree.
+ * @key:	The key we are looking for.
+ * @found_key:	Will hold the found item.
+ * @path:	Holds the current slot/leaf.
+ * @iter_ret:	Contains the value returned from btrfs_search_slot or
+ * 		btrfs_get_next_valid_item, whichever was executed last.
+ *
+ * The @iter_ret is an output variable that will contain the return value of
+ * btrfs_search_slot, if it encountered an error, or the value returned from
+ * btrfs_get_next_valid_item otherwise. That return value can be 0, if a valid
+ * slot was found, 1 if there were no more leaves, and <0 if there was an error.
+ *
+ * It's recommended to use a separate variable for iter_ret and then use it to
+ * set the function return value so there's no confusion of the 0/1/errno
+ * values stemming from btrfs_search_slot.
+ */
+#define btrfs_for_each_slot(root, key, found_key, path, iter_ret)		\
+	for (iter_ret = btrfs_search_slot(NULL, (root), (key), (path), 0, 0);	\
+		(iter_ret) >= 0 &&						\
+		(iter_ret = btrfs_get_next_valid_item((root), (found_key), (path))) == 0; \
+		(path)->slots[0]++						\
+	)
+
+int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq);
+
+/*
+ * Search the tree again to find a leaf with greater keys.
+ *
+ * Returns 0 if it found something or 1 if there are no greater leaves.
+ * Returns < 0 on error.
+ */
+static inline int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
+{
+	return btrfs_next_old_leaf(root, path, 0);
+}
+
+static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
+{
+	return btrfs_next_old_item(root, p, 0);
+}
+int btrfs_leaf_free_space(const struct extent_buffer *leaf);
+
+static inline bool btrfs_is_fstree(u64 rootid)
+{
+	if (rootid == BTRFS_FS_TREE_OBJECTID)
+		return true;
+
+	if ((s64)rootid < (s64)BTRFS_FIRST_FREE_OBJECTID)
+		return false;
+
+	if (btrfs_qgroup_level(rootid) != 0)
+		return false;
+
+	return true;
+}
+
+static inline bool btrfs_is_data_reloc_root(const struct btrfs_root *root)
+{
+	return root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID;
+}
+
+#endif