btrfs: constify extent_buffer in the API functions

There are many helpers around extent buffers, found in extent_io.h and
ctree.h. Most of them can be converted to take constified eb as there
are no changes to the extent buffer structure itself but rather the
pages.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 557de0dc904aa2709b6550519e1c4ad6aebbab8a..0a1fa1526c4351e74cc57cc4158a1e8bcab21295 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1384,7 +1384,7 @@ void btrfs_set_token_##bits(struct btrfs_map_token *token,                \
                            u##bits val);                               \
 u##bits btrfs_get_##bits(const struct extent_buffer *eb,               \
                         const void *ptr, unsigned long off);           \
-void btrfs_set_##bits(struct extent_buffer *eb, void *ptr,             \
+void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr,       \
                      unsigned long off, u##bits val);
 
 DECLARE_BTRFS_SETGET_BITS(8)
@@ -1399,7 +1399,7 @@ static inline u##bits btrfs_##name(const struct extent_buffer *eb,        \
        BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);   \
        return btrfs_get_##bits(eb, s, offsetof(type, member));         \
 }                                                                      \
-static inline void btrfs_set_##name(struct extent_buffer *eb, type *s, \
+static inline void btrfs_set_##name(const struct extent_buffer *eb, type *s, \
                                    u##bits val)                        \
 {                                                                      \
        BUILD_BUG_ON(sizeof(u##bits) != sizeof(((type *)0))->member);   \
@@ -1425,7 +1425,7 @@ static inline u##bits btrfs_##name(const struct extent_buffer *eb)        \
        u##bits res = le##bits##_to_cpu(p->member);                     \
        return res;                                                     \
 }                                                                      \
-static inline void btrfs_set_##name(struct extent_buffer *eb,          \
+static inline void btrfs_set_##name(const struct extent_buffer *eb,    \
                                    u##bits val)                        \
 {                                                                      \
        type *p = page_address(eb->pages[0]);                           \
@@ -1443,7 +1443,7 @@ static inline void btrfs_set_##name(type *s, u##bits val)         \
 }
 
 
-static inline u64 btrfs_device_total_bytes(struct extent_buffer *eb,
+static inline u64 btrfs_device_total_bytes(const struct extent_buffer *eb,
                                           struct btrfs_dev_item *s)
 {
        BUILD_BUG_ON(sizeof(u64) !=
@@ -1451,7 +1451,7 @@ static inline u64 btrfs_device_total_bytes(struct extent_buffer *eb,
        return btrfs_get_64(eb, s, offsetof(struct btrfs_dev_item,
                                            total_bytes));
 }
-static inline void btrfs_set_device_total_bytes(struct extent_buffer *eb,
+static inline void btrfs_set_device_total_bytes(const struct extent_buffer *eb,
                                                struct btrfs_dev_item *s,
                                                u64 val)
 {
@@ -1555,13 +1555,13 @@ static inline char *btrfs_stripe_dev_uuid_nr(struct btrfs_chunk *c, int nr)
        return btrfs_stripe_dev_uuid(btrfs_stripe_nr(c, nr));
 }
 
-static inline u64 btrfs_stripe_offset_nr(struct extent_buffer *eb,
+static inline u64 btrfs_stripe_offset_nr(const struct extent_buffer *eb,
                                         struct btrfs_chunk *c, int nr)
 {
        return btrfs_stripe_offset(eb, btrfs_stripe_nr(c, nr));
 }
 
-static inline u64 btrfs_stripe_devid_nr(struct extent_buffer *eb,
+static inline u64 btrfs_stripe_devid_nr(const struct extent_buffer *eb,
                                         struct btrfs_chunk *c, int nr)
 {
        return btrfs_stripe_devid(eb, btrfs_stripe_nr(c, nr));
@@ -1648,14 +1648,14 @@ BTRFS_SETGET_FUNCS(extent_flags, struct btrfs_extent_item, flags, 64);
 
 BTRFS_SETGET_FUNCS(tree_block_level, struct btrfs_tree_block_info, level, 8);
 
-static inline void btrfs_tree_block_key(struct extent_buffer *eb,
+static inline void btrfs_tree_block_key(const struct extent_buffer *eb,
                                        struct btrfs_tree_block_info *item,
                                        struct btrfs_disk_key *key)
 {
        read_eb_member(eb, item, struct btrfs_tree_block_info, key, key);
 }
 
-static inline void btrfs_set_tree_block_key(struct extent_buffer *eb,
+static inline void btrfs_set_tree_block_key(const struct extent_buffer *eb,
                                            struct btrfs_tree_block_info *item,
                                            struct btrfs_disk_key *key)
 {
@@ -1701,7 +1701,7 @@ BTRFS_SETGET_STACK_FUNCS(stack_key_blockptr, struct btrfs_key_ptr,
 BTRFS_SETGET_STACK_FUNCS(stack_key_generation, struct btrfs_key_ptr,
                         generation, 64);
 
-static inline u64 btrfs_node_blockptr(struct extent_buffer *eb, int nr)
+static inline u64 btrfs_node_blockptr(const struct extent_buffer *eb, int nr)
 {
        unsigned long ptr;
        ptr = offsetof(struct btrfs_node, ptrs) +
@@ -1709,7 +1709,7 @@ static inline u64 btrfs_node_blockptr(struct extent_buffer *eb, int nr)
        return btrfs_key_blockptr(eb, (struct btrfs_key_ptr *)ptr);
 }
 
-static inline void btrfs_set_node_blockptr(struct extent_buffer *eb,
+static inline void btrfs_set_node_blockptr(const struct extent_buffer *eb,
                                           int nr, u64 val)
 {
        unsigned long ptr;
@@ -1718,7 +1718,7 @@ static inline void btrfs_set_node_blockptr(struct extent_buffer *eb,
        btrfs_set_key_blockptr(eb, (struct btrfs_key_ptr *)ptr, val);
 }
 
-static inline u64 btrfs_node_ptr_generation(struct extent_buffer *eb, int nr)
+static inline u64 btrfs_node_ptr_generation(const struct extent_buffer *eb, int nr)
 {
        unsigned long ptr;
        ptr = offsetof(struct btrfs_node, ptrs) +
@@ -1726,7 +1726,7 @@ static inline u64 btrfs_node_ptr_generation(struct extent_buffer *eb, int nr)
        return btrfs_key_generation(eb, (struct btrfs_key_ptr *)ptr);
 }
 
-static inline void btrfs_set_node_ptr_generation(struct extent_buffer *eb,
+static inline void btrfs_set_node_ptr_generation(const struct extent_buffer *eb,
                                                 int nr, u64 val)
 {
        unsigned long ptr;
@@ -1744,7 +1744,7 @@ static inline unsigned long btrfs_node_key_ptr_offset(int nr)
 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,
+static inline void btrfs_set_node_key(const struct extent_buffer *eb,
                                      struct btrfs_disk_key *disk_key, int nr)
 {
        unsigned long ptr;

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 67ee46a0a9c8bd52c4a396a3bb078822fd1020ec..da6f0c1ed80c372a02626a0e49e6c72605466c40 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2333,7 +2333,7 @@ int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
        return 0;
 }
 
-int btrfs_repair_eb_io_failure(struct extent_buffer *eb, int mirror_num)
+int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num)
 {
        struct btrfs_fs_info *fs_info = eb->fs_info;
        u64 start = eb->start;
@@ -4910,7 +4910,7 @@ static void __free_extent_buffer(struct extent_buffer *eb)
        kmem_cache_free(extent_buffer_cache, eb);
 }
 
-int extent_buffer_under_io(struct extent_buffer *eb)
+int extent_buffer_under_io(const struct extent_buffer *eb)
 {
        return (atomic_read(&eb->io_pages) ||
                test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) ||
@@ -5018,7 +5018,7 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start,
        return eb;
 }
 
-struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
+struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src)
 {
        int i;
        struct page *p;
@@ -5424,7 +5424,7 @@ void free_extent_buffer_stale(struct extent_buffer *eb)
        release_extent_buffer(eb);
 }
 
-void clear_extent_buffer_dirty(struct extent_buffer *eb)
+void clear_extent_buffer_dirty(const struct extent_buffer *eb)
 {
        int i;
        int num_pages;
@@ -5720,7 +5720,7 @@ int memcmp_extent_buffer(const struct extent_buffer *eb, const void *ptrv,
        return ret;
 }
 
-void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
+void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
                const void *srcv)
 {
        char *kaddr;
@@ -5731,7 +5731,7 @@ void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,
                        BTRFS_FSID_SIZE);
 }
 
-void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)
+void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *srcv)
 {
        char *kaddr;
 
@@ -5741,7 +5741,7 @@ void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)
                        BTRFS_FSID_SIZE);
 }
 
-void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
+void write_extent_buffer(const struct extent_buffer *eb, const void *srcv,
                         unsigned long start, unsigned long len)
 {
        size_t cur;
@@ -5772,7 +5772,7 @@ void write_extent_buffer(struct extent_buffer *eb, const void *srcv,
        }
 }
 
-void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
+void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
                unsigned long len)
 {
        size_t cur;
@@ -5801,8 +5801,8 @@ void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
        }
 }
 
-void copy_extent_buffer_full(struct extent_buffer *dst,
-                            struct extent_buffer *src)
+void copy_extent_buffer_full(const struct extent_buffer *dst,
+                            const struct extent_buffer *src)
 {
        int i;
        int num_pages;
@@ -5815,7 +5815,8 @@ void copy_extent_buffer_full(struct extent_buffer *dst,
                                page_address(src->pages[i]));
 }
 
-void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
+void copy_extent_buffer(const struct extent_buffer *dst,
+                       const struct extent_buffer *src,
                        unsigned long dst_offset, unsigned long src_offset,
                        unsigned long len)
 {
@@ -5860,7 +5861,7 @@ void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
  * This helper hides the ugliness of finding the byte in an extent buffer which
  * contains a given bit.
  */
-static inline void eb_bitmap_offset(struct extent_buffer *eb,
+static inline void eb_bitmap_offset(const struct extent_buffer *eb,
                                    unsigned long start, unsigned long nr,
                                    unsigned long *page_index,
                                    size_t *page_offset)
@@ -5886,7 +5887,7 @@ static inline void eb_bitmap_offset(struct extent_buffer *eb,
  * @start: offset of the bitmap item in the extent buffer
  * @nr: bit number to test
  */
-int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
+int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
                           unsigned long nr)
 {
        u8 *kaddr;
@@ -5908,7 +5909,7 @@ int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
  * @pos: bit number of the first bit
  * @len: number of bits to set
  */
-void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
+void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
                              unsigned long pos, unsigned long len)
 {
        u8 *kaddr;
@@ -5950,8 +5951,9 @@ void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
  * @pos: bit number of the first bit
  * @len: number of bits to clear
  */
-void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
-                               unsigned long pos, unsigned long len)
+void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
+                               unsigned long start, unsigned long pos,
+                               unsigned long len)
 {
        u8 *kaddr;
        struct page *page;
@@ -6012,8 +6014,9 @@ static void copy_pages(struct page *dst_page, struct page *src_page,
                memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
 }
 
-void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
-                          unsigned long src_offset, unsigned long len)
+void memcpy_extent_buffer(const struct extent_buffer *dst,
+                         unsigned long dst_offset, unsigned long src_offset,
+                         unsigned long len)
 {
        struct btrfs_fs_info *fs_info = dst->fs_info;
        size_t cur;
@@ -6057,8 +6060,9 @@ void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
        }
 }
 
-void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
-                          unsigned long src_offset, unsigned long len)
+void memmove_extent_buffer(const struct extent_buffer *dst,
+                          unsigned long dst_offset, unsigned long src_offset,
+                          unsigned long len)
 {
        struct btrfs_fs_info *fs_info = dst->fs_info;
        size_t cur;

diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 9ed89c01e2dadcc1a22de6bb0de6de82aa166634..9a10681b12bff3e337b06a92542607edf05df14a 100644 (file)
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -213,7 +213,7 @@ struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
                                                  u64 start, unsigned long len);
 struct extent_buffer *alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info,
                                                u64 start);
-struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
+struct extent_buffer *btrfs_clone_extent_buffer(const struct extent_buffer *src);
 struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
                                         u64 start);
 void free_extent_buffer(struct extent_buffer *eb);
@@ -231,7 +231,7 @@ static inline int num_extent_pages(const struct extent_buffer *eb)
               (eb->start >> PAGE_SHIFT);
 }
 
-static inline int extent_buffer_uptodate(struct extent_buffer *eb)
+static inline int extent_buffer_uptodate(const struct extent_buffer *eb)
 {
        return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags);
 }
@@ -244,33 +244,37 @@ void read_extent_buffer(const struct extent_buffer *eb, void *dst,
 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,
+void write_extent_buffer_fsid(const struct extent_buffer *eb, const void *src);
+void write_extent_buffer_chunk_tree_uuid(const struct extent_buffer *eb,
                const void *src);
-void write_extent_buffer(struct extent_buffer *eb, const void *src,
+void write_extent_buffer(const struct extent_buffer *eb, const void *src,
                         unsigned long start, unsigned long len);
-void copy_extent_buffer_full(struct extent_buffer *dst,
-                            struct extent_buffer *src);
-void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
+void copy_extent_buffer_full(const struct extent_buffer *dst,
+                            const struct extent_buffer *src);
+void copy_extent_buffer(const struct extent_buffer *dst,
+                       const struct extent_buffer *src,
                        unsigned long dst_offset, unsigned long src_offset,
                        unsigned long len);
-void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
-                          unsigned long src_offset, unsigned long len);
-void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
-                          unsigned long src_offset, unsigned long len);
-void memzero_extent_buffer(struct extent_buffer *eb, unsigned long start,
+void memcpy_extent_buffer(const struct extent_buffer *dst,
+                         unsigned long dst_offset, unsigned long src_offset,
+                         unsigned long len);
+void memmove_extent_buffer(const struct extent_buffer *dst,
+                          unsigned long dst_offset, unsigned long src_offset,
                           unsigned long len);
-int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
+void memzero_extent_buffer(const struct extent_buffer *eb, unsigned long start,
+                          unsigned long len);
+int extent_buffer_test_bit(const struct extent_buffer *eb, unsigned long start,
                           unsigned long pos);
-void extent_buffer_bitmap_set(struct extent_buffer *eb, unsigned long start,
+void extent_buffer_bitmap_set(const struct extent_buffer *eb, unsigned long start,
                              unsigned long pos, unsigned long len);
-void extent_buffer_bitmap_clear(struct extent_buffer *eb, unsigned long start,
-                               unsigned long pos, unsigned long len);
-void clear_extent_buffer_dirty(struct extent_buffer *eb);
+void extent_buffer_bitmap_clear(const struct extent_buffer *eb,
+                               unsigned long start, unsigned long pos,
+                               unsigned long len);
+void clear_extent_buffer_dirty(const struct extent_buffer *eb);
 bool set_extent_buffer_dirty(struct extent_buffer *eb);
 void set_extent_buffer_uptodate(struct extent_buffer *eb);
 void clear_extent_buffer_uptodate(struct extent_buffer *eb);
-int extent_buffer_under_io(struct extent_buffer *eb);
+int extent_buffer_under_io(const struct extent_buffer *eb);
 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);
 void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
@@ -289,7 +293,7 @@ int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
                      u64 length, u64 logical, struct page *page,
                      unsigned int pg_offset, int mirror_num);
 void end_extent_writepage(struct page *page, int err, u64 start, u64 end);
-int btrfs_repair_eb_io_failure(struct extent_buffer *eb, int mirror_num);
+int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num);
 
 /*
  * When IO fails, either with EIO or csum verification fails, we

diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
index 67dfd1287c3ed3d70ba2b7dee43ae5102c1a8d1b..0b23aa0a32d5c444880673fc4015ac90311201b6 100644 (file)
--- a/fs/btrfs/struct-funcs.c
+++ b/fs/btrfs/struct-funcs.c
@@ -131,7 +131,7 @@ void btrfs_set_token_##bits(struct btrfs_map_token *token,          \
        leres = cpu_to_le##bits(val);                                   \
        write_extent_buffer(token->eb, &leres, member_offset, size);    \
 }                                                                      \
-void btrfs_set_##bits(struct extent_buffer *eb, void *ptr,             \
+void btrfs_set_##bits(const struct extent_buffer *eb, void *ptr,       \
                      unsigned long off, u##bits val)                   \
 {                                                                      \
        const unsigned long member_offset = (unsigned long)ptr + off;   \