Commit 1cbb1f45 authored by Jeff Mahoney's avatar Jeff Mahoney Committed by David Sterba
Browse files

btrfs: struct-funcs, constify readers 



We have reader helpers for most of the on-disk structures that use
an extent_buffer and pointer as offset into the buffer that are
read-only.  We should mark them as const and, in turn, allow consumers
of these interfaces to mark the buffers const as well.

No impact on code, but serves as documentation that a buffer is intended
not to be modified.

Signed-off-by: default avatarJeff Mahoney <jeffm@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 23d1f737

fs/btrfs/ctree.h

+66 −62
Original line number Diff line number Diff line
@@ -1434,7 +1434,7 @@ do { \ 
#define BTRFS_INODE_ROOT_ITEM_INIT	(1 << 31)



struct btrfs_map_token {

	struct extent_buffer *eb;

	const struct extent_buffer *eb;

	char *kaddr;

	unsigned long offset;

};
@@ -1468,13 +1468,14 @@ static inline void btrfs_init_map_token (struct btrfs_map_token *token) 
			   sizeof(((type *)0)->member)))



#define DECLARE_BTRFS_SETGET_BITS(bits)					\

u##bits btrfs_get_token_##bits(struct extent_buffer *eb, void *ptr,	\

			       unsigned long off,			\

u##bits btrfs_get_token_##bits(const struct extent_buffer *eb,		\

			       const void *ptr, unsigned long off,	\

			       struct btrfs_map_token *token);		\

void btrfs_set_token_##bits(struct extent_buffer *eb, void *ptr,	\

void btrfs_set_token_##bits(struct extent_buffer *eb, const void *ptr,	\

			    unsigned long off, u##bits val,		\

			    struct btrfs_map_token *token);		\

static inline u##bits btrfs_get_##bits(struct extent_buffer *eb, void *ptr, \

static inline u##bits btrfs_get_##bits(const struct extent_buffer *eb,	\

				       const void *ptr,			\

				       unsigned long off)		\

{									\

	return btrfs_get_token_##bits(eb, ptr, off, NULL);		\
@@ -1491,7 +1492,8 @@ DECLARE_BTRFS_SETGET_BITS(32) 
DECLARE_BTRFS_SETGET_BITS(64)



#define BTRFS_SETGET_FUNCS(name, type, member, bits)			\

static inline u##bits btrfs_##name(struct extent_buffer *eb, type *s)	\

static inline u##bits btrfs_##name(const struct extent_buffer *eb,	\

				   const type *s)			\

{									\

	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\

	return btrfs_get_##bits(eb, s, offsetof(type, member));		\
@@ -1502,7 +1504,8 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, type *s, \ 
	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\

	btrfs_set_##bits(eb, s, offsetof(type, member), val);		\

}									\

static inline u##bits btrfs_token_##name(struct extent_buffer *eb, type *s, \

static inline u##bits btrfs_token_##name(const struct extent_buffer *eb,\

					 const type *s,			\

					 struct btrfs_map_token *token)	\

{									\

	BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);	\
@@ -1517,9 +1520,9 @@ static inline void btrfs_set_token_##name(struct extent_buffer *eb, \ 
}



#define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits)		\

static inline u##bits btrfs_##name(struct extent_buffer *eb)		\

static inline u##bits btrfs_##name(const struct extent_buffer *eb)	\

{									\

	type *p = page_address(eb->pages[0]);				\

	const type *p = page_address(eb->pages[0]);			\

	u##bits res = le##bits##_to_cpu(p->member);			\

	return res;							\

}									\
@@ -1531,7 +1534,7 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, \ 
}



#define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits)		\

static inline u##bits btrfs_##name(type *s)				\

static inline u##bits btrfs_##name(const type *s)			\

{									\

	return le##bits##_to_cpu(s->member);				\

}									\
@@ -1856,7 +1859,7 @@ static inline unsigned long btrfs_node_key_ptr_offset(int nr) 
		sizeof(struct btrfs_key_ptr) * nr;

}



void btrfs_node_key(struct extent_buffer *eb,

void btrfs_node_key(const struct extent_buffer *eb,

		    struct btrfs_disk_key *disk_key, int nr);



static inline void btrfs_set_node_key(struct extent_buffer *eb,
@@ -1885,28 +1888,28 @@ static inline struct btrfs_item *btrfs_item_nr(int nr) 
	return (struct btrfs_item *)btrfs_item_nr_offset(nr);

}



static inline u32 btrfs_item_end(struct extent_buffer *eb,

static inline u32 btrfs_item_end(const struct extent_buffer *eb,

				 struct btrfs_item *item)

{

	return btrfs_item_offset(eb, item) + btrfs_item_size(eb, item);

}



static inline u32 btrfs_item_end_nr(struct extent_buffer *eb, int nr)

static inline u32 btrfs_item_end_nr(const struct extent_buffer *eb, int nr)

{

	return btrfs_item_end(eb, btrfs_item_nr(nr));

}



static inline u32 btrfs_item_offset_nr(struct extent_buffer *eb, int nr)

static inline u32 btrfs_item_offset_nr(const struct extent_buffer *eb, int nr)

{

	return btrfs_item_offset(eb, btrfs_item_nr(nr));

}



static inline u32 btrfs_item_size_nr(struct extent_buffer *eb, int nr)

static inline u32 btrfs_item_size_nr(const struct extent_buffer *eb, int nr)

{

	return btrfs_item_size(eb, btrfs_item_nr(nr));

}



static inline void btrfs_item_key(struct extent_buffer *eb,

static inline void btrfs_item_key(const struct extent_buffer *eb,

			   struct btrfs_disk_key *disk_key, int nr)

{

	struct btrfs_item *item = btrfs_item_nr(nr);
@@ -1942,8 +1945,8 @@ BTRFS_SETGET_STACK_FUNCS(stack_dir_name_len, struct btrfs_dir_item, 
BTRFS_SETGET_STACK_FUNCS(stack_dir_transid, struct btrfs_dir_item,

			 transid, 64);



static inline void btrfs_dir_item_key(struct extent_buffer *eb,

				      struct btrfs_dir_item *item,

static inline void btrfs_dir_item_key(const struct extent_buffer *eb,

				      const struct btrfs_dir_item *item,

				      struct btrfs_disk_key *key)

{

	read_eb_member(eb, item, struct btrfs_dir_item, location, key);
@@ -1951,7 +1954,7 @@ static inline void btrfs_dir_item_key(struct extent_buffer *eb, 


static inline void btrfs_set_dir_item_key(struct extent_buffer *eb,

					  struct btrfs_dir_item *item,

					  struct btrfs_disk_key *key)

					  const struct btrfs_disk_key *key)

{

	write_eb_member(eb, item, struct btrfs_dir_item, location, key);

}
@@ -1963,8 +1966,8 @@ BTRFS_SETGET_FUNCS(free_space_bitmaps, struct btrfs_free_space_header, 
BTRFS_SETGET_FUNCS(free_space_generation, struct btrfs_free_space_header,

		   generation, 64);



static inline void btrfs_free_space_key(struct extent_buffer *eb,

					struct btrfs_free_space_header *h,

static inline void btrfs_free_space_key(const struct extent_buffer *eb,

					const struct btrfs_free_space_header *h,

					struct btrfs_disk_key *key)

{

	read_eb_member(eb, h, struct btrfs_free_space_header, location, key);
@@ -1972,7 +1975,7 @@ static inline void btrfs_free_space_key(struct extent_buffer *eb, 


static inline void btrfs_set_free_space_key(struct extent_buffer *eb,

					    struct btrfs_free_space_header *h,

					    struct btrfs_disk_key *key)

					    const struct btrfs_disk_key *key)

{

	write_eb_member(eb, h, struct btrfs_free_space_header, location, key);

}
@@ -1999,7 +2002,7 @@ static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk, 
	disk->objectid = cpu_to_le64(cpu->objectid);

}



static inline void btrfs_node_key_to_cpu(struct extent_buffer *eb,

static inline void btrfs_node_key_to_cpu(const struct extent_buffer *eb,

					 struct btrfs_key *key, int nr)

{

	struct btrfs_disk_key disk_key;
@@ -2007,7 +2010,7 @@ static inline void btrfs_node_key_to_cpu(struct extent_buffer *eb, 
	btrfs_disk_key_to_cpu(key, &disk_key);

}



static inline void btrfs_item_key_to_cpu(struct extent_buffer *eb,

static inline void btrfs_item_key_to_cpu(const struct extent_buffer *eb,

					 struct btrfs_key *key, int nr)

{

	struct btrfs_disk_key disk_key;
@@ -2015,8 +2018,8 @@ static inline void btrfs_item_key_to_cpu(struct extent_buffer *eb, 
	btrfs_disk_key_to_cpu(key, &disk_key);

}



static inline void btrfs_dir_item_key_to_cpu(struct extent_buffer *eb,

				      struct btrfs_dir_item *item,

static inline void btrfs_dir_item_key_to_cpu(const struct extent_buffer *eb,

					     const struct btrfs_dir_item *item,

					     struct btrfs_key *key)

{

	struct btrfs_disk_key disk_key;
@@ -2049,7 +2052,7 @@ BTRFS_SETGET_STACK_FUNCS(stack_header_nritems, struct btrfs_header, 
			 nritems, 32);

BTRFS_SETGET_STACK_FUNCS(stack_header_bytenr, struct btrfs_header, bytenr, 64);



static inline int btrfs_header_flag(struct extent_buffer *eb, u64 flag)

static inline int btrfs_header_flag(const struct extent_buffer *eb, u64 flag)

{

	return (btrfs_header_flags(eb) & flag) == flag;

}
@@ -2068,7 +2071,7 @@ static inline int btrfs_clear_header_flag(struct extent_buffer *eb, u64 flag) 
	return (flags & flag) == flag;

}



static inline int btrfs_header_backref_rev(struct extent_buffer *eb)

static inline int btrfs_header_backref_rev(const struct extent_buffer *eb)

{

	u64 flags = btrfs_header_flags(eb);

	return flags >> BTRFS_BACKREF_REV_SHIFT;
@@ -2088,12 +2091,12 @@ static inline unsigned long btrfs_header_fsid(void) 
	return offsetof(struct btrfs_header, fsid);

}



static inline unsigned long btrfs_header_chunk_tree_uuid(struct extent_buffer *eb)

static inline unsigned long btrfs_header_chunk_tree_uuid(const struct extent_buffer *eb)

{

	return offsetof(struct btrfs_header, chunk_tree_uuid);

}



static inline int btrfs_is_leaf(struct extent_buffer *eb)

static inline int btrfs_is_leaf(const struct extent_buffer *eb)

{

	return btrfs_header_level(eb) == 0;

}
@@ -2127,12 +2130,12 @@ BTRFS_SETGET_STACK_FUNCS(root_stransid, struct btrfs_root_item, 
BTRFS_SETGET_STACK_FUNCS(root_rtransid, struct btrfs_root_item,

			 rtransid, 64);



static inline bool btrfs_root_readonly(struct btrfs_root *root)

static inline bool btrfs_root_readonly(const struct btrfs_root *root)

{

	return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0;

}



static inline bool btrfs_root_dead(struct btrfs_root *root)

static inline bool btrfs_root_dead(const struct btrfs_root *root)

{

	return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_DEAD)) != 0;

}
@@ -2189,8 +2192,8 @@ BTRFS_SETGET_STACK_FUNCS(backup_num_devices, struct btrfs_root_backup, 
/* struct btrfs_balance_item */

BTRFS_SETGET_FUNCS(balance_flags, struct btrfs_balance_item, flags, 64);



static inline void btrfs_balance_data(struct extent_buffer *eb,

				      struct btrfs_balance_item *bi,

static inline void btrfs_balance_data(const struct extent_buffer *eb,

				      const struct btrfs_balance_item *bi,

				      struct btrfs_disk_balance_args *ba)

{

	read_eb_member(eb, bi, struct btrfs_balance_item, data, ba);
@@ -2198,13 +2201,13 @@ static inline void btrfs_balance_data(struct extent_buffer *eb, 


static inline void btrfs_set_balance_data(struct extent_buffer *eb,

				  struct btrfs_balance_item *bi,

					  struct btrfs_disk_balance_args *ba)

				  const struct btrfs_disk_balance_args *ba)

{

	write_eb_member(eb, bi, struct btrfs_balance_item, data, ba);

}



static inline void btrfs_balance_meta(struct extent_buffer *eb,

				      struct btrfs_balance_item *bi,

static inline void btrfs_balance_meta(const struct extent_buffer *eb,

				      const struct btrfs_balance_item *bi,

				      struct btrfs_disk_balance_args *ba)

{

	read_eb_member(eb, bi, struct btrfs_balance_item, meta, ba);
@@ -2212,13 +2215,13 @@ static inline void btrfs_balance_meta(struct extent_buffer *eb, 


static inline void btrfs_set_balance_meta(struct extent_buffer *eb,

				  struct btrfs_balance_item *bi,

					  struct btrfs_disk_balance_args *ba)

				  const struct btrfs_disk_balance_args *ba)

{

	write_eb_member(eb, bi, struct btrfs_balance_item, meta, ba);

}



static inline void btrfs_balance_sys(struct extent_buffer *eb,

				     struct btrfs_balance_item *bi,

static inline void btrfs_balance_sys(const struct extent_buffer *eb,

				     const struct btrfs_balance_item *bi,

				     struct btrfs_disk_balance_args *ba)

{

	read_eb_member(eb, bi, struct btrfs_balance_item, sys, ba);
@@ -2226,14 +2229,14 @@ static inline void btrfs_balance_sys(struct extent_buffer *eb, 


static inline void btrfs_set_balance_sys(struct extent_buffer *eb,

				 struct btrfs_balance_item *bi,

					 struct btrfs_disk_balance_args *ba)

				 const struct btrfs_disk_balance_args *ba)

{

	write_eb_member(eb, bi, struct btrfs_balance_item, sys, ba);

}



static inline void

btrfs_disk_balance_args_to_cpu(struct btrfs_balance_args *cpu,

			       struct btrfs_disk_balance_args *disk)

			       const struct btrfs_disk_balance_args *disk)

{

	memset(cpu, 0, sizeof(*cpu));
@@ -2253,7 +2256,7 @@ btrfs_disk_balance_args_to_cpu(struct btrfs_balance_args *cpu, 


static inline void

btrfs_cpu_balance_args_to_disk(struct btrfs_disk_balance_args *disk,

			       struct btrfs_balance_args *cpu)

			       const struct btrfs_balance_args *cpu)

{

	memset(disk, 0, sizeof(*disk));
@@ -2321,7 +2324,7 @@ BTRFS_SETGET_STACK_FUNCS(super_magic, struct btrfs_super_block, magic, 64); 
BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block,

			 uuid_tree_generation, 64);



static inline int btrfs_super_csum_size(struct btrfs_super_block *s)

static inline int btrfs_super_csum_size(const struct btrfs_super_block *s)

{

	u16 t = btrfs_super_csum_type(s);

	/*
@@ -2336,8 +2339,8 @@ static inline int btrfs_super_csum_size(struct btrfs_super_block *s) 
 * this returns the address of the start of the last item,

 * which is the stop of the leaf data stack

 */

static inline unsigned int leaf_data_end(struct btrfs_fs_info *fs_info,

					 struct extent_buffer *leaf)

static inline unsigned int leaf_data_end(const struct btrfs_fs_info *fs_info,

					 const struct extent_buffer *leaf)

{

	u32 nr = btrfs_header_nritems(leaf);
@@ -2362,7 +2365,7 @@ BTRFS_SETGET_STACK_FUNCS(stack_file_extent_compression, 
			 struct btrfs_file_extent_item, compression, 8);



static inline unsigned long

btrfs_file_extent_inline_start(struct btrfs_file_extent_item *e)

btrfs_file_extent_inline_start(const struct btrfs_file_extent_item *e)

{

	return (unsigned long)e + BTRFS_FILE_EXTENT_INLINE_DATA_START;

}
@@ -2396,7 +2399,8 @@ BTRFS_SETGET_FUNCS(file_extent_other_encoding, struct btrfs_file_extent_item, 
 * size of any extent headers.  If a file is compressed on disk, this is

 * the compressed size

 */

static inline u32 btrfs_file_extent_inline_item_len(struct extent_buffer *eb,

static inline u32 btrfs_file_extent_inline_item_len(

						const struct extent_buffer *eb,

						struct btrfs_item *e)

{

	return btrfs_item_size(eb, e) - BTRFS_FILE_EXTENT_INLINE_DATA_START;
@@ -2405,9 +2409,9 @@ static inline u32 btrfs_file_extent_inline_item_len(struct extent_buffer *eb, 
/* this returns the number of file bytes represented by the inline item.

 * If an item is compressed, this is the uncompressed size

 */

static inline u32 btrfs_file_extent_inline_len(struct extent_buffer *eb,

static inline u32 btrfs_file_extent_inline_len(const struct extent_buffer *eb,

					int slot,

					       struct btrfs_file_extent_item *fi)

					const struct btrfs_file_extent_item *fi)

{

	struct btrfs_map_token token;
@@ -2429,8 +2433,8 @@ static inline u32 btrfs_file_extent_inline_len(struct extent_buffer *eb, 




/* btrfs_dev_stats_item */

static inline u64 btrfs_dev_stats_value(struct extent_buffer *eb,

					struct btrfs_dev_stats_item *ptr,

static inline u64 btrfs_dev_stats_value(const struct extent_buffer *eb,

					const struct btrfs_dev_stats_item *ptr,

					int index)

{

	u64 val;

fs/btrfs/extent_io.c

+11 −13
Original line number Diff line number Diff line
@@ -5405,9 +5405,8 @@ unlock_exit: 
	return ret;

}



void read_extent_buffer(struct extent_buffer *eb, void *dstv,

			unsigned long start,

			unsigned long len)

void read_extent_buffer(const struct extent_buffer *eb, void *dstv,

			unsigned long start, unsigned long len)

{

	size_t cur;

	size_t offset;
@@ -5436,9 +5435,9 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv, 
	}

}



int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv,

			unsigned long start,

			unsigned long len)

int read_extent_buffer_to_user(const struct extent_buffer *eb,

			       void __user *dstv,

			       unsigned long start, unsigned long len)

{

	size_t cur;

	size_t offset;
@@ -5478,9 +5477,9 @@ int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv, 
 * return 1 if the item spans two pages.

 * return -EINVAL otherwise.

 */

int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,

			       unsigned long min_len, char **map,

			       unsigned long *map_start,

int map_private_extent_buffer(const struct extent_buffer *eb,

			      unsigned long start, unsigned long min_len,

			      char **map, unsigned long *map_start,

			      unsigned long *map_len)

{

	size_t offset = start & (PAGE_SIZE - 1);
@@ -5515,9 +5514,8 @@ int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start, 
	return 0;

}



int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,

			  unsigned long start,

			  unsigned long len)

int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,

			 unsigned long start, unsigned long len)

{

	size_t cur;

	size_t offset;

fs/btrfs/extent_io.h

+9 −10
Original line number Diff line number Diff line
@@ -449,14 +449,13 @@ static inline void extent_buffer_get(struct extent_buffer *eb) 
	atomic_inc(&eb->refs);

}



int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,

			  unsigned long start,

			  unsigned long len);

void read_extent_buffer(struct extent_buffer *eb, void *dst,

int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,

			 unsigned long start, unsigned long len);

void read_extent_buffer(const struct extent_buffer *eb, void *dst,

			unsigned long start,

			unsigned long len);

int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dst,

			       unsigned long start,

int read_extent_buffer_to_user(const struct extent_buffer *eb,

			       void __user *dst, unsigned long start,

			       unsigned long len);

void write_extent_buffer_fsid(struct extent_buffer *eb, const void *src);

void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
@@ -486,9 +485,9 @@ void set_extent_buffer_uptodate(struct extent_buffer *eb); 
void clear_extent_buffer_uptodate(struct extent_buffer *eb);

int extent_buffer_uptodate(struct extent_buffer *eb);

int extent_buffer_under_io(struct extent_buffer *eb);

int map_private_extent_buffer(struct extent_buffer *eb, unsigned long offset,

		      unsigned long min_len, char **map,

		      unsigned long *map_start,

int map_private_extent_buffer(const struct extent_buffer *eb,

			      unsigned long offset, unsigned long min_len,

			      char **map, unsigned long *map_start,

			      unsigned long *map_len);

void extent_range_clear_dirty_for_io(struct inode *inode, u64 start, u64 end);

void extent_range_redirty_for_io(struct inode *inode, u64 start, u64 end);

fs/btrfs/struct-funcs.c

+5 −4
Original line number Diff line number Diff line
@@ -50,8 +50,8 @@ static inline void put_unaligned_le8(u8 val, void *p) 
 */



#define DEFINE_BTRFS_SETGET_BITS(bits)					\

u##bits btrfs_get_token_##bits(struct extent_buffer *eb, void *ptr,	\

			       unsigned long off,			\

u##bits btrfs_get_token_##bits(const struct extent_buffer *eb,		\

			       const void *ptr, unsigned long off,	\

			       struct btrfs_map_token *token)		\

{									\

	unsigned long part_offset = (unsigned long)ptr;			\
@@ -90,7 +90,8 @@ u##bits btrfs_get_token_##bits(struct extent_buffer *eb, void *ptr, \ 
	return res;							\

}									\

void btrfs_set_token_##bits(struct extent_buffer *eb,			\

			    void *ptr, unsigned long off, u##bits val,	\

			    const void *ptr, unsigned long off,		\

			    u##bits val,				\

			    struct btrfs_map_token *token)		\

{									\

	unsigned long part_offset = (unsigned long)ptr;			\
@@ -133,7 +134,7 @@ DEFINE_BTRFS_SETGET_BITS(16) 
DEFINE_BTRFS_SETGET_BITS(32)

DEFINE_BTRFS_SETGET_BITS(64)



void btrfs_node_key(struct extent_buffer *eb,

void btrfs_node_key(const struct extent_buffer *eb,

		    struct btrfs_disk_key *disk_key, int nr)

{

	unsigned long ptr = btrfs_node_key_ptr_offset(nr);

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