Commit 8e225f04 authored by Damien Le Moal's avatar Damien Le Moal Committed by Mike Snitzer

dm crypt: Enable zoned block device support

Enable support for zoned block devices. This is done by:
1) implementing the target report_zones method.
2) adding the DM_TARGET_ZONED_HM flag to the target features.
3) setting DM_CRYPT_NO_WRITE_WORKQUEUE flag to avoid IO
   processing via workqueue.
4) Introducing inline write encryption completion to preserve write
   ordering.

The last point is implemented by introducing the internal flag
DM_CRYPT_WRITE_INLINE. When set, kcryptd_crypt_write_convert() always
waits inline for the completion of a write request encryption if the
request is not already completed once crypt_convert() returns.
Completion of write request encryption is signaled using the
restart completion by kcryptd_async_done(). This mechanism allows
using ciphers that have an asynchronous implementation, isolating
dm-crypt from any potential request completion reordering for these
ciphers.
Signed-off-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 39d42fa9
......@@ -129,7 +129,8 @@ struct iv_elephant_private {
*/
enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE };
DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE,
DM_CRYPT_WRITE_INLINE };
enum cipher_flags {
CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cihper */
......@@ -1919,9 +1920,32 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
spin_unlock_irqrestore(&cc->write_thread_lock, flags);
}
static bool kcryptd_crypt_write_inline(struct crypt_config *cc,
struct convert_context *ctx)
{
if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags))
return false;
/*
* Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering
* constraints so they do not need to be issued inline by
* kcryptd_crypt_write_convert().
*/
switch (bio_op(ctx->bio_in)) {
case REQ_OP_WRITE:
case REQ_OP_WRITE_SAME:
case REQ_OP_WRITE_ZEROES:
return true;
default:
return false;
}
}
static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
{
struct crypt_config *cc = io->cc;
struct convert_context *ctx = &io->ctx;
struct bio *clone;
int crypt_finished;
sector_t sector = io->sector;
......@@ -1931,7 +1955,7 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
* Prevent io from disappearing until this function completes.
*/
crypt_inc_pending(io);
crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
crypt_convert_init(cc, ctx, NULL, io->base_bio, sector);
clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
if (unlikely(!clone)) {
......@@ -1945,11 +1969,16 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
sector += bio_sectors(clone);
crypt_inc_pending(io);
r = crypt_convert(cc, &io->ctx,
r = crypt_convert(cc, ctx,
test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags));
if (r)
io->error = r;
crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
/* Wait for completion signaled by kcryptd_async_done() */
wait_for_completion(&ctx->restart);
crypt_finished = 1;
}
/* Encryption was already finished, submit io now */
if (crypt_finished) {
......@@ -2021,9 +2050,20 @@ static void kcryptd_async_done(struct crypto_async_request *async_req,
if (!atomic_dec_and_test(&ctx->cc_pending))
return;
if (bio_data_dir(io->base_bio) == READ)
/*
* The request is fully completed: for inline writes, let
* kcryptd_crypt_write_convert() do the IO submission.
*/
if (bio_data_dir(io->base_bio) == READ) {
kcryptd_crypt_read_done(io);
else
return;
}
if (kcryptd_crypt_write_inline(cc, ctx)) {
complete(&ctx->restart);
return;
}
kcryptd_crypt_write_io_submit(io, 1);
}
......@@ -2936,6 +2976,21 @@ static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **ar
return 0;
}
#ifdef CONFIG_BLK_DEV_ZONED
static int crypt_report_zones(struct dm_target *ti,
struct dm_report_zones_args *args, unsigned int nr_zones)
{
struct crypt_config *cc = ti->private;
sector_t sector = cc->start + dm_target_offset(ti, args->next_sector);
args->start = cc->start;
return blkdev_report_zones(cc->dev->bdev, sector, nr_zones,
dm_report_zones_cb, args);
}
#endif
/*
* Construct an encryption mapping:
* <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
......@@ -3069,6 +3124,16 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
}
cc->start = tmpll;
/*
* For zoned block devices, we need to preserve the issuer write
* ordering. To do so, disable write workqueues and force inline
* encryption completion.
*/
if (bdev_is_zoned(cc->dev->bdev)) {
set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags);
}
if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
ret = crypt_integrity_ctr(cc, ti);
if (ret)
......@@ -3358,6 +3423,10 @@ static struct target_type crypt_target = {
.module = THIS_MODULE,
.ctr = crypt_ctr,
.dtr = crypt_dtr,
#ifdef CONFIG_BLK_DEV_ZONED
.features = DM_TARGET_ZONED_HM,
.report_zones = crypt_report_zones,
#endif
.map = crypt_map,
.status = crypt_status,
.postsuspend = crypt_postsuspend,
......
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