提交 4d53dddb 编写于 作者: D David Sterba

btrfs: document existence of extent_io ops callbacks

Some of the callbacks defined in btree_extent_io_ops and
btrfs_extent_io_ops do always exist so we don't need to check the
existence before each call. This patch just reorders the definition and
documents which are mandatory/optional.
Signed-off-by: NDavid Sterba <dsterba@suse.com>
上级 c3988d63
......@@ -4653,9 +4653,12 @@ static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
}
static const struct extent_io_ops btree_extent_io_ops = {
.readpage_end_io_hook = btree_readpage_end_io_hook,
.readpage_io_failed_hook = btree_io_failed_hook,
/* mandatory callbacks */
.submit_bio_hook = btree_submit_bio_hook,
.readpage_end_io_hook = btree_readpage_end_io_hook,
/* note we're sharing with inode.c for the merge bio hook */
.merge_bio_hook = btrfs_merge_bio_hook,
/* optional callbacks */
.readpage_io_failed_hook = btree_io_failed_hook,
};
......@@ -92,18 +92,27 @@ typedef int (extent_submit_bio_hook_t)(struct inode *inode, struct bio *bio,
int mirror_num, unsigned long bio_flags,
u64 bio_offset);
struct extent_io_ops {
int (*fill_delalloc)(struct inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written);
int (*writepage_start_hook)(struct page *page, u64 start, u64 end);
/*
* The following callbacks must be allways defined, the function
* pointer will be called unconditionally.
*/
extent_submit_bio_hook_t *submit_bio_hook;
int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,
struct page *page, u64 start, u64 end,
int mirror);
int (*merge_bio_hook)(struct page *page, unsigned long offset,
size_t size, struct bio *bio,
unsigned long bio_flags);
/*
* Optional hooks, called if the pointer is not NULL
*/
int (*fill_delalloc)(struct inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written);
int (*readpage_io_failed_hook)(struct page *page, int failed_mirror);
int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset,
struct page *page, u64 start, u64 end,
int mirror);
int (*writepage_start_hook)(struct page *page, u64 start, u64 end);
void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
struct extent_state *state, int uptodate);
void (*set_bit_hook)(struct inode *inode, struct extent_state *state,
......
......@@ -10547,10 +10547,13 @@ static const struct file_operations btrfs_dir_file_operations = {
};
static const struct extent_io_ops btrfs_extent_io_ops = {
.fill_delalloc = run_delalloc_range,
/* mandatory callbacks */
.submit_bio_hook = btrfs_submit_bio_hook,
.merge_bio_hook = btrfs_merge_bio_hook,
.readpage_end_io_hook = btrfs_readpage_end_io_hook,
.merge_bio_hook = btrfs_merge_bio_hook,
/* optional callbacks */
.fill_delalloc = run_delalloc_range,
.writepage_end_io_hook = btrfs_writepage_end_io_hook,
.writepage_start_hook = btrfs_writepage_start_hook,
.set_bit_hook = btrfs_set_bit_hook,
......
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