[PATCH] dm crypt: use private biosets
In the low memory situation dm-crypt needs to use a private mempool of bios to
avoid blocking.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index c34433a..655d816 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -77,6 +77,7 @@
*/
mempool_t *io_pool;
mempool_t *page_pool;
+ struct bio_set *bs;
/*
* crypto related data
@@ -95,7 +96,7 @@
u8 key[0];
};
-#define MIN_IOS 256
+#define MIN_IOS 16
#define MIN_POOL_PAGES 32
#define MIN_BIO_PAGES 8
@@ -311,6 +312,14 @@
return r;
}
+ static void dm_crypt_bio_destructor(struct bio *bio)
+ {
+ struct crypt_io *io = bio->bi_private;
+ struct crypt_config *cc = io->target->private;
+
+ bio_free(bio, cc->bs);
+ }
+
/*
* Generate a new unfragmented bio with the given size
* This should never violate the device limitations
@@ -325,18 +334,17 @@
gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
unsigned int i;
- /*
- * Use __GFP_NOMEMALLOC to tell the VM to act less aggressively and
- * to fail earlier. This is not necessary but increases throughput.
- * FIXME: Is this really intelligent?
- */
- if (base_bio)
- clone = bio_clone(base_bio, GFP_NOIO|__GFP_NOMEMALLOC);
- else
- clone = bio_alloc(GFP_NOIO|__GFP_NOMEMALLOC, nr_iovecs);
+ if (base_bio) {
+ clone = bio_alloc_bioset(GFP_NOIO, base_bio->bi_max_vecs, cc->bs);
+ __bio_clone(clone, base_bio);
+ } else
+ clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
+
if (!clone)
return NULL;
+ clone->bi_destructor = dm_crypt_bio_destructor;
+
/* if the last bio was not complete, continue where that one ended */
clone->bi_idx = *bio_vec_idx;
clone->bi_vcnt = *bio_vec_idx;
@@ -517,13 +525,14 @@
* copy the required bvecs because we need the original
* one in order to decrypt the whole bio data *afterwards*.
*/
- clone = bio_alloc(GFP_NOIO, bio_segments(base_bio));
+ clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
if (unlikely(!clone)) {
dec_pending(io, -ENOMEM);
return;
}
clone_init(io, clone);
+ clone->bi_destructor = dm_crypt_bio_destructor;
clone->bi_idx = 0;
clone->bi_vcnt = bio_segments(base_bio);
clone->bi_size = base_bio->bi_size;
@@ -594,7 +603,6 @@
/* out of memory -> run queues */
if (remaining)
blk_congestion_wait(bio_data_dir(clone), HZ/100);
-
}
}
@@ -804,6 +812,12 @@
goto bad4;
}
+ cc->bs = bioset_create(MIN_IOS, MIN_IOS, 4);
+ if (!cc->bs) {
+ ti->error = "Cannot allocate crypt bioset";
+ goto bad_bs;
+ }
+
if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
ti->error = "Error setting key";
goto bad5;
@@ -843,6 +857,8 @@
return 0;
bad5:
+ bioset_free(cc->bs);
+bad_bs:
mempool_destroy(cc->page_pool);
bad4:
mempool_destroy(cc->io_pool);
@@ -862,6 +878,7 @@
{
struct crypt_config *cc = (struct crypt_config *) ti->private;
+ bioset_free(cc->bs);
mempool_destroy(cc->page_pool);
mempool_destroy(cc->io_pool);