dm mpath: cleanup 'struct dm_mpath_io' management code

Refactor and rename existing interfaces to be more specific and
self-documenting.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Mike Snitzer 2016-02-03 09:13:14 -05:00
parent 8637a6bf14
commit 2eff1924e1

View File

@ -228,30 +228,35 @@ static void free_multipath(struct multipath *m)
kfree(m);
}
static int set_mapinfo(struct multipath *m, union map_info *info)
static struct dm_mpath_io *get_mpio(union map_info *info)
{
return info->ptr;
}
static struct dm_mpath_io *set_mpio(struct multipath *m, union map_info *info)
{
struct dm_mpath_io *mpio;
if (!m->mpio_pool) {
/* Use blk-mq pdu memory requested via per_io_data_size */
mpio = info->ptr;
mpio = get_mpio(info);
memset(mpio, 0, sizeof(*mpio));
return mpio;
}
mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC);
if (!mpio)
return -ENOMEM;
return NULL;
memset(mpio, 0, sizeof(*mpio));
info->ptr = mpio;
return 0;
return mpio;
}
static void clear_mapinfo(struct multipath *m, union map_info *info)
static void clear_request_fn_mpio(struct multipath *m, union map_info *info)
{
/* Only needed for non blk-mq */
/* Only needed for non blk-mq (.request_fn) multipath */
if (m->mpio_pool) {
struct dm_mpath_io *mpio = info->ptr;
@ -421,11 +426,11 @@ static int __multipath_map(struct dm_target *ti, struct request *clone,
goto out_unlock;
}
if (set_mapinfo(m, map_context) < 0)
mpio = set_mpio(m, map_context);
if (!mpio)
/* ENOMEM, requeue */
goto out_unlock;
mpio = map_context->ptr;
mpio->pgpath = pgpath;
mpio->nr_bytes = nr_bytes;
@ -451,7 +456,7 @@ static int __multipath_map(struct dm_target *ti, struct request *clone,
rq_data_dir(rq), GFP_ATOMIC);
if (IS_ERR(*__clone)) {
/* ENOMEM, requeue */
clear_mapinfo(m, map_context);
clear_request_fn_mpio(m, map_context);
return r;
}
(*__clone)->bio = (*__clone)->biotail = NULL;
@ -1317,21 +1322,21 @@ static int multipath_end_io(struct dm_target *ti, struct request *clone,
int error, union map_info *map_context)
{
struct multipath *m = ti->private;
struct dm_mpath_io *mpio = map_context->ptr;
struct dm_mpath_io *mpio = get_mpio(map_context);
struct pgpath *pgpath;
struct path_selector *ps;
int r;
BUG_ON(!mpio);
r = do_end_io(m, clone, error, mpio);
r = do_end_io(m, clone, error, mpio);
pgpath = mpio->pgpath;
if (pgpath) {
ps = &pgpath->pg->ps;
if (ps->type->end_io)
ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes);
}
clear_mapinfo(m, map_context);
clear_request_fn_mpio(m, map_context);
return r;
}