raid5-cache: use a bio_set
This allows us to make guaranteed forward progress.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.com>
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index c1c4d21..2a64497 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -34,6 +34,12 @@
#define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */
#define RECLAIM_MAX_FREE_SPACE_SHIFT (2)
+/*
+ * We only need 2 bios per I/O unit to make progress, but ensure we
+ * have a few more available to not get too tight.
+ */
+#define R5L_POOL_SIZE 4
+
struct r5l_log {
struct md_rdev *rdev;
@@ -70,6 +76,7 @@
struct bio flush_bio;
struct kmem_cache *io_kc;
+ struct bio_set *bs;
struct md_thread *reclaim_thread;
unsigned long reclaim_target; /* number of space that need to be
@@ -248,7 +255,7 @@
static struct bio *r5l_bio_alloc(struct r5l_log *log)
{
- struct bio *bio = bio_kmalloc(GFP_NOIO | __GFP_NOFAIL, BIO_MAX_PAGES);
+ struct bio *bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES, log->bs);
bio->bi_rw = WRITE;
bio->bi_bdev = log->rdev->bdev;
@@ -1161,6 +1168,10 @@
if (!log->io_kc)
goto io_kc;
+ log->bs = bioset_create(R5L_POOL_SIZE, 0);
+ if (!log->bs)
+ goto io_bs;
+
log->reclaim_thread = md_register_thread(r5l_reclaim_thread,
log->rdev->mddev, "reclaim");
if (!log->reclaim_thread)
@@ -1178,6 +1189,8 @@
error:
md_unregister_thread(&log->reclaim_thread);
reclaim_thread:
+ bioset_free(log->bs);
+io_bs:
kmem_cache_destroy(log->io_kc);
io_kc:
kfree(log);
@@ -1187,6 +1200,7 @@
void r5l_exit_log(struct r5l_log *log)
{
md_unregister_thread(&log->reclaim_thread);
+ bioset_free(log->bs);
kmem_cache_destroy(log->io_kc);
kfree(log);
}