btrfs: constify pointer parameters where applicable

We can add const to many parameters, this is for clarity and minor
addition to safety. There are some minor effects, in the assembly
code and .ko measured on release config. This patch does not cover all
possible conversions.

Signed-off-by: David Sterba <[email protected]>

Author: kdave

fs/btrfs/btrfs_inode.h

@@ -413,12 +413,12 @@ static inline void btrfs_i_size_write(struct btrfs_inode *inode, u64 size)
 	inode->disk_i_size = size;
 }
 
-static inline bool btrfs_is_free_space_inode(struct btrfs_inode *inode)
+static inline bool btrfs_is_free_space_inode(const struct btrfs_inode *inode)
 {
 	return test_bit(BTRFS_INODE_FREE_SPACE_INODE, &inode->runtime_flags);
 }
 
-static inline bool is_data_inode(struct inode *inode)
+static inline bool is_data_inode(const struct inode *inode)
 {
 	return btrfs_ino(BTRFS_I(inode)) != BTRFS_BTREE_INODE_OBJECTID;
 }

fs/btrfs/delalloc-space.c

@@ -111,7 +111,7 @@
  *  making error handling and cleanup easier.
  */
 
-int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes)
+int btrfs_alloc_data_chunk_ondemand(const struct btrfs_inode *inode, u64 bytes)
 {
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;

fs/btrfs/delalloc-space.h

@@ -9,7 +9,7 @@ struct extent_changeset;
 struct btrfs_inode;
 struct btrfs_fs_info;
 
-int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes);
+int btrfs_alloc_data_chunk_ondemand(const struct btrfs_inode *inode, u64 bytes);
 int btrfs_check_data_free_space(struct btrfs_inode *inode,
 			struct extent_changeset **reserved, u64 start, u64 len,
 			bool noflush);

fs/btrfs/delayed-inode.c

@@ -1469,7 +1469,7 @@ static void btrfs_release_dir_index_item_space(struct btrfs_trans_handle *trans)
 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
 				   const char *name, int name_len,
 				   struct btrfs_inode *dir,
-				   struct btrfs_disk_key *disk_key, u8 flags,
+				   const struct btrfs_disk_key *disk_key, u8 flags,
 				   u64 index)
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
@@ -1755,7 +1755,7 @@ void btrfs_readdir_put_delayed_items(struct inode *inode,
 	downgrade_write(&inode->i_rwsem);
 }
 
-int btrfs_should_delete_dir_index(struct list_head *del_list,
+int btrfs_should_delete_dir_index(const struct list_head *del_list,
 				  u64 index)
 {
 	struct btrfs_delayed_item *curr;
@@ -1776,7 +1776,7 @@ int btrfs_should_delete_dir_index(struct list_head *del_list,
  * Read dir info stored in the delayed tree.
  */
 int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
-				    struct list_head *ins_list)
+				    const struct list_head *ins_list)
 {
 	struct btrfs_dir_item *di;
 	struct btrfs_delayed_item *curr, *next;

fs/btrfs/delayed-inode.h

@@ -110,7 +110,7 @@ void btrfs_init_delayed_root(struct btrfs_delayed_root *delayed_root);
 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
 				   const char *name, int name_len,
 				   struct btrfs_inode *dir,
-				   struct btrfs_disk_key *disk_key, u8 flags,
+				   const struct btrfs_disk_key *disk_key, u8 flags,
 				   u64 index);
 
 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,
@@ -150,10 +150,10 @@ bool btrfs_readdir_get_delayed_items(struct inode *inode,
 void btrfs_readdir_put_delayed_items(struct inode *inode,
 				     struct list_head *ins_list,
 				     struct list_head *del_list);
-int btrfs_should_delete_dir_index(struct list_head *del_list,
+int btrfs_should_delete_dir_index(const struct list_head *del_list,
 				  u64 index);
 int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
-				    struct list_head *ins_list);
+				    const struct list_head *ins_list);
 
 /* Used during directory logging. */
 void btrfs_log_get_delayed_items(struct btrfs_inode *inode,

fs/btrfs/dir-item.c

@@ -22,7 +22,7 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
 						   *trans,
 						   struct btrfs_root *root,
 						   struct btrfs_path *path,
-						   struct btrfs_key *cpu_key,
+						   const struct btrfs_key *cpu_key,
 						   u32 data_size,
 						   const char *name,
 						   int name_len)
@@ -108,7 +108,7 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
  */
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans,
 			  const struct fscrypt_str *name, struct btrfs_inode *dir,
-			  struct btrfs_key *location, u8 type, u64 index)
+			  const struct btrfs_key *location, u8 type, u64 index)
 {
 	int ret = 0;
 	int ret2 = 0;
@@ -379,7 +379,7 @@ struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
  * for a specific name.
  */
 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_fs_info *fs_info,
-						 struct btrfs_path *path,
+						 const struct btrfs_path *path,
 						 const char *name, int name_len)
 {
 	struct btrfs_dir_item *dir_item;
@@ -417,7 +417,7 @@ struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_fs_info *fs_info,
 int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root,
 			      struct btrfs_path *path,
-			      struct btrfs_dir_item *di)
+			      const struct btrfs_dir_item *di)
 {
 
 	struct extent_buffer *leaf;

fs/btrfs/dir-item.h

@@ -17,7 +17,7 @@ int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
 			  const struct fscrypt_str *name);
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans,
 			  const struct fscrypt_str *name, struct btrfs_inode *dir,
-			  struct btrfs_key *location, u8 type, u64 index);
+			  const struct btrfs_key *location, u8 type, u64 index);
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 					     struct btrfs_root *root,
 					     struct btrfs_path *path, u64 dir,
@@ -33,7 +33,7 @@ struct btrfs_dir_item *btrfs_search_dir_index_item(struct btrfs_root *root,
 int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root,
 			      struct btrfs_path *path,
-			      struct btrfs_dir_item *di);
+			      const struct btrfs_dir_item *di);
 int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
 			    struct btrfs_root *root,
 			    struct btrfs_path *path, u64 objectid,
@@ -45,7 +45,7 @@ struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
 					  const char *name, u16 name_len,
 					  int mod);
 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_fs_info *fs_info,
-						 struct btrfs_path *path,
+						 const struct btrfs_path *path,
 						 const char *name,
 						 int name_len);
 

fs/btrfs/disk-io.c

@@ -213,7 +213,7 @@ static int btrfs_repair_eb_io_failure(const struct extent_buffer *eb,
  *			structure for details.
  */
 int btrfs_read_extent_buffer(struct extent_buffer *eb,
-			     struct btrfs_tree_parent_check *check)
+			     const struct btrfs_tree_parent_check *check)
 {
 	struct btrfs_fs_info *fs_info = eb->fs_info;
 	int failed = 0;
@@ -358,7 +358,7 @@ static bool check_tree_block_fsid(struct extent_buffer *eb)
 
 /* Do basic extent buffer checks at read time */
 int btrfs_validate_extent_buffer(struct extent_buffer *eb,
-				 struct btrfs_tree_parent_check *check)
+				 const struct btrfs_tree_parent_check *check)
 {
 	struct btrfs_fs_info *fs_info = eb->fs_info;
 	u64 found_start;
@@ -425,7 +425,7 @@ int btrfs_validate_extent_buffer(struct extent_buffer *eb,
 		goto out;
 	}
 	if (check->has_first_key) {
-		struct btrfs_key *expect_key = &check->first_key;
+		const struct btrfs_key *expect_key = &check->first_key;
 		struct btrfs_key found_key;
 
 		if (found_level)
@@ -1025,7 +1025,7 @@ int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
 
 static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root,
 					      struct btrfs_path *path,
-					      struct btrfs_key *key)
+					      const struct btrfs_key *key)
 {
 	struct btrfs_root *root;
 	struct btrfs_tree_parent_check check = { 0 };
@@ -1087,7 +1087,7 @@ static struct btrfs_root *read_tree_root_path(struct btrfs_root *tree_root,
 }
 
 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
-					struct btrfs_key *key)
+					const struct btrfs_key *key)
 {
 	struct btrfs_root *root;
 	struct btrfs_path *path;
@@ -1222,7 +1222,7 @@ int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
 	return ret;
 }
 
-void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info)
+void btrfs_check_leaked_roots(const struct btrfs_fs_info *fs_info)
 {
 #ifdef CONFIG_BTRFS_DEBUG
 	struct btrfs_root *root;
@@ -2339,8 +2339,8 @@ static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
  * 		1, 2	2nd and 3rd backup copy
  * 	       -1	skip bytenr check
  */
-int btrfs_validate_super(struct btrfs_fs_info *fs_info,
-			 struct btrfs_super_block *sb, int mirror_num)
+int btrfs_validate_super(const struct btrfs_fs_info *fs_info,
+			 const struct btrfs_super_block *sb, int mirror_num)
 {
 	u64 nodesize = btrfs_super_nodesize(sb);
 	u64 sectorsize = btrfs_super_sectorsize(sb);
@@ -3192,7 +3192,7 @@ int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount)
 }
 
 int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices,
-		      char *options)
+		      const char *options)
 {
 	u32 sectorsize;
 	u32 nodesize;

fs/btrfs/disk-io.h

@@ -41,7 +41,7 @@ static inline u64 btrfs_sb_offset(int mirror)
 	return BTRFS_SUPER_INFO_OFFSET;
 }
 
-void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info);
+void btrfs_check_leaked_roots(const struct btrfs_fs_info *fs_info);
 void btrfs_init_fs_info(struct btrfs_fs_info *fs_info);
 struct extent_buffer *read_tree_block(struct btrfs_fs_info *fs_info, u64 bytenr,
 				      struct btrfs_tree_parent_check *check);
@@ -52,20 +52,19 @@ struct extent_buffer *btrfs_find_create_tree_block(
 int btrfs_start_pre_rw_mount(struct btrfs_fs_info *fs_info);
 int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 			   const struct btrfs_super_block *disk_sb);
-int __cold open_ctree(struct super_block *sb,
-	       struct btrfs_fs_devices *fs_devices,
-	       char *options);
+int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices,
+		      const char *options);
 void __cold close_ctree(struct btrfs_fs_info *fs_info);
-int btrfs_validate_super(struct btrfs_fs_info *fs_info,
-			 struct btrfs_super_block *sb, int mirror_num);
+int btrfs_validate_super(const struct btrfs_fs_info *fs_info,
+			 const struct btrfs_super_block *sb, int mirror_num);
 int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount);
 int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors);
 struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev);
 struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev,
 						   int copy_num, bool drop_cache);
 int btrfs_commit_super(struct btrfs_fs_info *fs_info);
 struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root,
-					struct btrfs_key *key);
+					const struct btrfs_key *key);
 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
 			 struct btrfs_root *root);
 void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info);
@@ -90,7 +89,7 @@ void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
 				 struct btrfs_root *root);
 int btrfs_validate_extent_buffer(struct extent_buffer *eb,
-				 struct btrfs_tree_parent_check *check);
+				 const struct btrfs_tree_parent_check *check);
 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
 struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
 #endif
@@ -117,7 +116,7 @@ void btrfs_mark_buffer_dirty(struct btrfs_trans_handle *trans,
 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
 			  int atomic);
 int btrfs_read_extent_buffer(struct extent_buffer *buf,
-			     struct btrfs_tree_parent_check *check);
+			     const struct btrfs_tree_parent_check *check);
 
 blk_status_t btree_csum_one_bio(struct btrfs_bio *bbio);
 int btrfs_alloc_log_tree_node(struct btrfs_trans_handle *trans,

fs/btrfs/extent_io.c

@@ -180,7 +180,7 @@ void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end)
 }
 
 static void process_one_page(struct btrfs_fs_info *fs_info,
-			     struct page *page, struct page *locked_page,
+			     struct page *page, const struct page *locked_page,
 			     unsigned long page_ops, u64 start, u64 end)
 {
 	struct folio *folio = page_folio(page);
@@ -203,7 +203,7 @@ static void process_one_page(struct btrfs_fs_info *fs_info,
 }
 
 static void __process_pages_contig(struct address_space *mapping,
-				   struct page *locked_page, u64 start, u64 end,
+				   const struct page *locked_page, u64 start, u64 end,
 				   unsigned long page_ops)
 {
 	struct btrfs_fs_info *fs_info = inode_to_fs_info(mapping->host);
@@ -230,8 +230,8 @@ static void __process_pages_contig(struct address_space *mapping,
 	}
 }
 
-static noinline void __unlock_for_delalloc(struct inode *inode,
-					   struct page *locked_page,
+static noinline void __unlock_for_delalloc(const struct inode *inode,
+					   const struct page *locked_page,
 					   u64 start, u64 end)
 {
 	unsigned long index = start >> PAGE_SHIFT;
@@ -246,7 +246,7 @@ static noinline void __unlock_for_delalloc(struct inode *inode,
 }
 
 static noinline int lock_delalloc_pages(struct inode *inode,
-					struct page *locked_page,
+					const struct page *locked_page,
 					u64 start,
 					u64 end)
 {
@@ -411,7 +411,7 @@ noinline_for_stack bool find_lock_delalloc_range(struct inode *inode,
 }
 
 void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
-				  struct page *locked_page,
+				  const struct page *locked_page,
 				  struct extent_state **cached,
 				  u32 clear_bits, unsigned long page_ops)
 {
@@ -1382,7 +1382,7 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode,
  * Return the next dirty range in [@start, @end).
  * If no dirty range is found, @start will be page_offset(page) + PAGE_SIZE.
  */
-static void find_next_dirty_byte(struct btrfs_fs_info *fs_info,
+static void find_next_dirty_byte(const struct btrfs_fs_info *fs_info,
 				 struct page *page, u64 *start, u64 *end)
 {
 	struct folio *folio = page_folio(page);
@@ -1743,7 +1743,7 @@ static void set_btree_ioerr(struct extent_buffer *eb)
  * context.
  */
 static struct extent_buffer *find_extent_buffer_nolock(
-		struct btrfs_fs_info *fs_info, u64 start)
+		const struct btrfs_fs_info *fs_info, u64 start)
 {
 	struct extent_buffer *eb;
 
@@ -2312,7 +2312,7 @@ static int extent_write_cache_pages(struct address_space *mapping,
  * already been ran (aka, ordered extent inserted) and all pages are still
  * locked.
  */
-void extent_write_locked_range(struct inode *inode, struct page *locked_page,
+void extent_write_locked_range(struct inode *inode, const struct page *locked_page,
 			       u64 start, u64 end, struct writeback_control *wbc,
 			       bool pages_dirty)
 {
@@ -2597,7 +2597,7 @@ static bool folio_range_has_eb(struct btrfs_fs_info *fs_info, struct folio *foli
 	return false;
 }
 
-static void detach_extent_buffer_folio(struct extent_buffer *eb, struct folio *folio)
+static void detach_extent_buffer_folio(const struct extent_buffer *eb, struct folio *folio)
 {
 	struct btrfs_fs_info *fs_info = eb->fs_info;
 	const bool mapped = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags);
@@ -2658,7 +2658,7 @@ static void detach_extent_buffer_folio(struct extent_buffer *eb, struct folio *f
 }
 
 /* Release all pages attached to the extent buffer */
-static void btrfs_release_extent_buffer_pages(struct extent_buffer *eb)
+static void btrfs_release_extent_buffer_pages(const struct extent_buffer *eb)
 {
 	ASSERT(!extent_buffer_under_io(eb));
 
@@ -3573,7 +3573,7 @@ static void end_bbio_meta_read(struct btrfs_bio *bbio)
 }
 
 int read_extent_buffer_pages(struct extent_buffer *eb, int wait, int mirror_num,
-			     struct btrfs_tree_parent_check *check)
+			     const struct btrfs_tree_parent_check *check)
 {
 	struct btrfs_bio *bbio;
 	bool ret;
@@ -4186,7 +4186,7 @@ void memmove_extent_buffer(const struct extent_buffer *dst,
 
 #define GANG_LOOKUP_SIZE	16
 static struct extent_buffer *get_next_extent_buffer(
-		struct btrfs_fs_info *fs_info, struct page *page, u64 bytenr)
+		const struct btrfs_fs_info *fs_info, struct page *page, u64 bytenr)
 {
 	struct extent_buffer *gang[GANG_LOOKUP_SIZE];
 	struct extent_buffer *found = NULL;