bcache: Use standard utility code
Some of bcache's utility code has made it into the rest of the kernel,
so drop the bcache versions.
Bcache used to have a workaround for allocating from a bio set under
generic_make_request() (if you allocated more than once, the bios you
already allocated would get stuck on current->bio_list when you
submitted, and you'd risk deadlock) - bcache would mask out __GFP_WAIT
when allocating bios under generic_make_request() so that allocation
could fail and it could retry from workqueue. But bio_alloc_bioset() has
a workaround now, so we can drop this hack and the associated error
handling.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
diff --git a/drivers/md/bcache/io.c b/drivers/md/bcache/io.c
index 0f6d696..9056632 100644
--- a/drivers/md/bcache/io.c
+++ b/drivers/md/bcache/io.c
@@ -68,13 +68,6 @@
* The newly allocated bio will point to @bio's bi_io_vec, if the split was on a
* bvec boundry; it is the caller's responsibility to ensure that @bio is not
* freed before the split.
- *
- * If bch_bio_split() is running under generic_make_request(), it's not safe to
- * allocate more than one bio from the same bio set. Therefore, if it is running
- * under generic_make_request() it masks out __GFP_WAIT when doing the
- * allocation. The caller must check for failure if there's any possibility of
- * it being called from under generic_make_request(); it is then the caller's
- * responsibility to retry from a safe context (by e.g. punting to workqueue).
*/
struct bio *bch_bio_split(struct bio *bio, int sectors,
gfp_t gfp, struct bio_set *bs)
@@ -85,15 +78,6 @@
BUG_ON(sectors <= 0);
- /*
- * If we're being called from underneath generic_make_request() and we
- * already allocated any bios from this bio set, we risk deadlock if we
- * use the mempool. So instead, we possibly fail and let the caller punt
- * to workqueue or somesuch and retry in a safe context.
- */
- if (current->bio_list)
- gfp &= ~__GFP_WAIT;
-
if (sectors >= bio_sectors(bio))
return bio;
@@ -164,17 +148,18 @@
struct request_queue *q = bdev_get_queue(bio->bi_bdev);
unsigned max_segments = min_t(unsigned, BIO_MAX_PAGES,
queue_max_segments(q));
- struct bio_vec *bv, *end = bio_iovec(bio) +
- min_t(int, bio_segments(bio), max_segments);
if (bio->bi_rw & REQ_DISCARD)
return min(ret, q->limits.max_discard_sectors);
if (bio_segments(bio) > max_segments ||
q->merge_bvec_fn) {
+ struct bio_vec *bv;
+ int i, seg = 0;
+
ret = 0;
- for (bv = bio_iovec(bio); bv < end; bv++) {
+ bio_for_each_segment(bv, bio, i) {
struct bvec_merge_data bvm = {
.bi_bdev = bio->bi_bdev,
.bi_sector = bio->bi_sector,
@@ -182,10 +167,14 @@
.bi_rw = bio->bi_rw,
};
+ if (seg == max_segments)
+ break;
+
if (q->merge_bvec_fn &&
q->merge_bvec_fn(q, &bvm, bv) < (int) bv->bv_len)
break;
+ seg++;
ret += bv->bv_len >> 9;
}
}
@@ -222,30 +211,10 @@
closure_put(cl);
}
-static void __bch_bio_submit_split(struct closure *cl)
-{
- struct bio_split_hook *s = container_of(cl, struct bio_split_hook, cl);
- struct bio *bio = s->bio, *n;
-
- do {
- n = bch_bio_split(bio, bch_bio_max_sectors(bio),
- GFP_NOIO, s->p->bio_split);
- if (!n)
- continue_at(cl, __bch_bio_submit_split, system_wq);
-
- n->bi_end_io = bch_bio_submit_split_endio;
- n->bi_private = cl;
-
- closure_get(cl);
- bch_generic_make_request_hack(n);
- } while (n != bio);
-
- continue_at(cl, bch_bio_submit_split_done, NULL);
-}
-
void bch_generic_make_request(struct bio *bio, struct bio_split_pool *p)
{
struct bio_split_hook *s;
+ struct bio *n;
if (!bio_has_data(bio) && !(bio->bi_rw & REQ_DISCARD))
goto submit;
@@ -254,6 +223,7 @@
goto submit;
s = mempool_alloc(p->bio_split_hook, GFP_NOIO);
+ closure_init(&s->cl, NULL);
s->bio = bio;
s->p = p;
@@ -261,8 +231,18 @@
s->bi_private = bio->bi_private;
bio_get(bio);
- closure_call(&s->cl, __bch_bio_submit_split, NULL, NULL);
- return;
+ do {
+ n = bch_bio_split(bio, bch_bio_max_sectors(bio),
+ GFP_NOIO, s->p->bio_split);
+
+ n->bi_end_io = bch_bio_submit_split_endio;
+ n->bi_private = &s->cl;
+
+ closure_get(&s->cl);
+ bch_generic_make_request_hack(n);
+ } while (n != bio);
+
+ continue_at(&s->cl, bch_bio_submit_split_done, NULL);
submit:
bch_generic_make_request_hack(bio);
}