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/extent_io.c b/fs/btrfs/extent_io.c
index 67ee46a..da6f0c1 100644
--- 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;