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[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>
This commit is contained in:
Milan Broz 2006-10-03 01:15:40 -07:00 committed by Linus Torvalds
parent 23541d2d28
commit 6a24c71843
1 changed files with 29 additions and 12 deletions
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41
drivers/md/dm-crypt.c
View File

@ -77,6 +77,7 @@ struct crypt_config {
*/
mempool_t *io_pool;
mempool_t *page_pool;
struct bio_set *bs;
/*
* crypto related data
@ -95,7 +96,7 @@ struct crypt_config {
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 @@ static int crypt_convert(struct crypt_config *cc,
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 @@ crypt_alloc_buffer(struct crypt_config *cc, unsigned int size,
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 @@ static void process_read(struct crypt_io *io)
* 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 @@ static void process_write(struct crypt_io *io)
/* out of memory -> run queues */
if (remaining)
blk_congestion_wait(bio_data_dir(clone), HZ/100);
}
}
@ -804,6 +812,12 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
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 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
return 0;
bad5:
bioset_free(cc->bs);
bad_bs:
mempool_destroy(cc->page_pool);
bad4:
mempool_destroy(cc->io_pool);
@ -862,6 +878,7 @@ static void crypt_dtr(struct dm_target *ti)
{
struct crypt_config *cc = (struct crypt_config *) ti->private;
bioset_free(cc->bs);
mempool_destroy(cc->page_pool);
mempool_destroy(cc->io_pool);