dm: rename bio cloning functions
Rename functions involved in splitting and cloning bios.
The sequence of functions is now:
(1) __split_and_process* - entry point that selects the processing strategy
(2) __send* - prepare the details for each bio needed and loop through them
(3) __clone_and_map* - creates a clone and maps it
Signed-off-by: Alasdair G Kergon <[email protected]>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index caef71b..02079cf 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1061,9 +1061,9 @@
/*
* Creates a little bio that just does part of a bvec.
*/
-static void split_bvec(struct dm_target_io *tio, struct bio *bio,
- sector_t sector, unsigned short idx, unsigned int offset,
- unsigned int len)
+static void clone_split_bio(struct dm_target_io *tio, struct bio *bio,
+ sector_t sector, unsigned short idx,
+ unsigned offset, unsigned len)
{
struct bio *clone = &tio->clone;
struct bio_vec *bv = bio->bi_io_vec + idx;
@@ -1119,8 +1119,9 @@
return tio;
}
-static void __issue_target_request(struct clone_info *ci, struct dm_target *ti,
- unsigned target_bio_nr, sector_t len)
+static void __clone_and_map_simple_bio(struct clone_info *ci,
+ struct dm_target *ti,
+ unsigned target_bio_nr, sector_t len)
{
struct dm_target_io *tio = alloc_tio(ci, ti, ci->bio->bi_max_vecs, target_bio_nr);
struct bio *clone = &tio->clone;
@@ -1137,31 +1138,29 @@
__map_bio(tio);
}
-static void __issue_target_bios(struct clone_info *ci, struct dm_target *ti,
- unsigned num_bios, sector_t len)
+static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
+ unsigned num_bios, sector_t len)
{
unsigned target_bio_nr;
for (target_bio_nr = 0; target_bio_nr < num_bios; target_bio_nr++)
- __issue_target_request(ci, ti, target_bio_nr, len);
+ __clone_and_map_simple_bio(ci, ti, target_bio_nr, len);
}
-static int __clone_and_map_empty_flush(struct clone_info *ci)
+static int __send_empty_flush(struct clone_info *ci)
{
unsigned target_nr = 0;
struct dm_target *ti;
BUG_ON(bio_has_data(ci->bio));
while ((ti = dm_table_get_target(ci->map, target_nr++)))
- __issue_target_bios(ci, ti, ti->num_flush_bios, 0);
+ __send_duplicate_bios(ci, ti, ti->num_flush_bios, 0);
return 0;
}
-/*
- * Perform all io with a single clone.
- */
-static void __clone_and_map_simple(struct clone_info *ci, struct dm_target *ti)
+static void __clone_and_map_data_bio(struct clone_info *ci,
+ struct dm_target *ti)
{
struct bio *bio = ci->bio;
struct dm_target_io *tio;
@@ -1192,9 +1191,9 @@
return ti->split_discard_bios;
}
-static int __clone_and_map_changing_extent_only(struct clone_info *ci,
- get_num_bios_fn get_num_bios,
- is_split_required_fn is_split_required)
+static int __send_changing_extent_only(struct clone_info *ci,
+ get_num_bios_fn get_num_bios,
+ is_split_required_fn is_split_required)
{
struct dm_target *ti;
sector_t len;
@@ -1220,7 +1219,7 @@
else
len = min(ci->sector_count, max_io_len(ci->sector, ti));
- __issue_target_bios(ci, ti, num_bios, len);
+ __send_duplicate_bios(ci, ti, num_bios, len);
ci->sector += len;
} while (ci->sector_count -= len);
@@ -1228,18 +1227,18 @@
return 0;
}
-static int __clone_and_map_discard(struct clone_info *ci)
+static int __send_discard(struct clone_info *ci)
{
- return __clone_and_map_changing_extent_only(ci, get_num_discard_bios,
- is_split_required_for_discard);
+ return __send_changing_extent_only(ci, get_num_discard_bios,
+ is_split_required_for_discard);
}
-static int __clone_and_map_write_same(struct clone_info *ci)
+static int __send_write_same(struct clone_info *ci)
{
- return __clone_and_map_changing_extent_only(ci, get_num_write_same_bios, NULL);
+ return __send_changing_extent_only(ci, get_num_write_same_bios, NULL);
}
-static int __clone_and_map(struct clone_info *ci)
+static int __split_and_process_non_flush(struct clone_info *ci)
{
struct bio *bio = ci->bio;
struct dm_target *ti;
@@ -1247,9 +1246,9 @@
struct dm_target_io *tio;
if (unlikely(bio->bi_rw & REQ_DISCARD))
- return __clone_and_map_discard(ci);
+ return __send_discard(ci);
else if (unlikely(bio->bi_rw & REQ_WRITE_SAME))
- return __clone_and_map_write_same(ci);
+ return __send_write_same(ci);
ti = dm_table_find_target(ci->map, ci->sector);
if (!dm_target_is_valid(ti))
@@ -1262,7 +1261,7 @@
* Optimise for the simple case where we can do all of
* the remaining io with a single clone.
*/
- __clone_and_map_simple(ci, ti);
+ __clone_and_map_data_bio(ci, ti);
} else if (to_sector(bio->bi_io_vec[ci->idx].bv_len) <= max) {
/*
@@ -1311,8 +1310,8 @@
len = min(remaining, max);
tio = alloc_tio(ci, ti, 1, 0);
- split_bvec(tio, bio, ci->sector, ci->idx,
- bv->bv_offset + offset, len);
+ clone_split_bio(tio, bio, ci->sector, ci->idx,
+ bv->bv_offset + offset, len);
__map_bio(tio);
@@ -1328,7 +1327,7 @@
}
/*
- * Split the bio into several clones and submit it to targets.
+ * Entry point to split a bio into clones and submit them to the targets.
*/
static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
{
@@ -1356,13 +1355,13 @@
if (bio->bi_rw & REQ_FLUSH) {
ci.bio = &ci.md->flush_bio;
ci.sector_count = 0;
- error = __clone_and_map_empty_flush(&ci);
+ error = __send_empty_flush(&ci);
/* dec_pending submits any data associated with flush */
} else {
ci.bio = bio;
ci.sector_count = bio_sectors(bio);
while (ci.sector_count && !error)
- error = __clone_and_map(&ci);
+ error = __split_and_process_non_flush(&ci);
}
/* drop the extra reference count */
