diff options
| -rw-r--r-- | Documentation/admin-guide/device-mapper/dm-crypt.rst | 11 | ||||
| -rw-r--r-- | drivers/md/dm-crypt.c | 32 |
2 files changed, 40 insertions, 3 deletions
diff --git a/Documentation/admin-guide/device-mapper/dm-crypt.rst b/Documentation/admin-guide/device-mapper/dm-crypt.rst index 41f5f57f00eb..e625830d335e 100644 --- a/Documentation/admin-guide/device-mapper/dm-crypt.rst +++ b/Documentation/admin-guide/device-mapper/dm-crypt.rst @@ -160,6 +160,17 @@ iv_large_sectors The <iv_offset> must be multiple of <sector_size> (in 512 bytes units) if this flag is specified. + +Module parameters:: +max_read_size +max_write_size + Maximum size of read or write requests. When a request larger than this size + is received, dm-crypt will split the request. The splitting improves + concurrency (the split requests could be encrypted in parallel by multiple + cores), but it also causes overhead. The user should tune these parameters to + fit the actual workload. + + Example scripts =============== LUKS (Linux Unified Key Setup) is now the preferred way to set up disk diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 6c013ceb0e5f..f46ff843d4c3 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -241,6 +241,31 @@ static unsigned int dm_crypt_clients_n; static volatile unsigned long dm_crypt_pages_per_client; #define DM_CRYPT_MEMORY_PERCENT 2 #define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_VECS * 16) +#define DM_CRYPT_DEFAULT_MAX_READ_SIZE 131072 +#define DM_CRYPT_DEFAULT_MAX_WRITE_SIZE 131072 + +static unsigned int max_read_size = 0; +module_param(max_read_size, uint, 0644); +MODULE_PARM_DESC(max_read_size, "Maximum size of a read request"); +static unsigned int max_write_size = 0; +module_param(max_write_size, uint, 0644); +MODULE_PARM_DESC(max_write_size, "Maximum size of a write request"); +static unsigned get_max_request_size(struct crypt_config *cc, bool wrt) +{ + unsigned val, sector_align; + val = !wrt ? READ_ONCE(max_read_size) : READ_ONCE(max_write_size); + if (likely(!val)) + val = !wrt ? DM_CRYPT_DEFAULT_MAX_READ_SIZE : DM_CRYPT_DEFAULT_MAX_WRITE_SIZE; + if (wrt || cc->on_disk_tag_size) { + if (unlikely(val > BIO_MAX_VECS << PAGE_SHIFT)) + val = BIO_MAX_VECS << PAGE_SHIFT; + } + sector_align = max(bdev_logical_block_size(cc->dev->bdev), (unsigned)cc->sector_size); + val = round_down(val, sector_align); + if (unlikely(!val)) + val = sector_align; + return val >> SECTOR_SHIFT; +} static void crypt_endio(struct bio *clone); static void kcryptd_queue_crypt(struct dm_crypt_io *io); @@ -3474,6 +3499,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio) { struct dm_crypt_io *io; struct crypt_config *cc = ti->private; + unsigned max_sectors; /* * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues. @@ -3492,9 +3518,9 @@ static int crypt_map(struct dm_target *ti, struct bio *bio) /* * Check if bio is too large, split as needed. */ - if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_VECS << PAGE_SHIFT)) && - (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size)) - dm_accept_partial_bio(bio, ((BIO_MAX_VECS << PAGE_SHIFT) >> SECTOR_SHIFT)); + max_sectors = get_max_request_size(cc, bio_data_dir(bio) == WRITE); + if (unlikely(bio_sectors(bio) > max_sectors)) + dm_accept_partial_bio(bio, max_sectors); /* * Ensure that bio is a multiple of internal sector encryption size |