btrfs: document more parameters of submit_extent_page

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index fecf1e5c4f97fd7e984aef12c2fb964f9b746b68..f27bad003f8e218454044f60914f70c4cfeb1bff 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2746,7 +2746,19 @@ static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
 
 /*
  * @opf:       bio REQ_OP_* and REQ_* flags as one value
+ * @tree:      tree so we can call our merge_bio hook
+ * @wbc:       optional writeback control for io accounting
+ * @page:      page to add to the bio
+ * @pg_offset: offset of the new bio or to check whether we are adding
+ *              a contiguous page to the previous one
+ * @size:      portion of page that we want to write
+ * @offset:    starting offset in the page
+ * @bdev:      attach newly created bios to this bdev
  * @bio_ret:   must be valid pointer, newly allocated bio will be stored there
+ * @end_io_func:     end_io callback for new bio
+ * @mirror_num:             desired mirror to read/write
+ * @prev_bio_flags:  flags of previous bio to see if we can merge the current one
+ * @bio_flags: flags of the current bio to see if we can merge them
  */
 static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
                              struct writeback_control *wbc,