summaryrefslogtreecommitdiff
path: root/drivers/md/dm-crypt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/md/dm-crypt.c')
-rw-r--r--drivers/md/dm-crypt.c170
1 files changed, 152 insertions, 18 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 53791138d78b..5a55617a08e6 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1454,13 +1454,16 @@ static int crypt_convert_block_skcipher(struct crypt_config *cc,
static void kcryptd_async_done(struct crypto_async_request *async_req,
int error);
-static void crypt_alloc_req_skcipher(struct crypt_config *cc,
+static int crypt_alloc_req_skcipher(struct crypt_config *cc,
struct convert_context *ctx)
{
unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
- if (!ctx->r.req)
- ctx->r.req = mempool_alloc(&cc->req_pool, GFP_NOIO);
+ if (!ctx->r.req) {
+ ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
+ if (!ctx->r.req)
+ return -ENOMEM;
+ }
skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
@@ -1471,13 +1474,18 @@ static void crypt_alloc_req_skcipher(struct crypt_config *cc,
skcipher_request_set_callback(ctx->r.req,
CRYPTO_TFM_REQ_MAY_BACKLOG,
kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
+
+ return 0;
}
-static void crypt_alloc_req_aead(struct crypt_config *cc,
+static int crypt_alloc_req_aead(struct crypt_config *cc,
struct convert_context *ctx)
{
- if (!ctx->r.req_aead)
- ctx->r.req_aead = mempool_alloc(&cc->req_pool, GFP_NOIO);
+ if (!ctx->r.req_aead) {
+ ctx->r.req_aead = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
+ if (!ctx->r.req_aead)
+ return -ENOMEM;
+ }
aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
@@ -1488,15 +1496,17 @@ static void crypt_alloc_req_aead(struct crypt_config *cc,
aead_request_set_callback(ctx->r.req_aead,
CRYPTO_TFM_REQ_MAY_BACKLOG,
kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
+
+ return 0;
}
-static void crypt_alloc_req(struct crypt_config *cc,
+static int crypt_alloc_req(struct crypt_config *cc,
struct convert_context *ctx)
{
if (crypt_integrity_aead(cc))
- crypt_alloc_req_aead(cc, ctx);
+ return crypt_alloc_req_aead(cc, ctx);
else
- crypt_alloc_req_skcipher(cc, ctx);
+ return crypt_alloc_req_skcipher(cc, ctx);
}
static void crypt_free_req_skcipher(struct crypt_config *cc,
@@ -1529,17 +1539,28 @@ static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_
* Encrypt / decrypt data from one bio to another one (can be the same one)
*/
static blk_status_t crypt_convert(struct crypt_config *cc,
- struct convert_context *ctx, bool atomic)
+ struct convert_context *ctx, bool atomic, bool reset_pending)
{
unsigned int tag_offset = 0;
unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
int r;
- atomic_set(&ctx->cc_pending, 1);
+ /*
+ * if reset_pending is set we are dealing with the bio for the first time,
+ * else we're continuing to work on the previous bio, so don't mess with
+ * the cc_pending counter
+ */
+ if (reset_pending)
+ atomic_set(&ctx->cc_pending, 1);
while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
- crypt_alloc_req(cc, ctx);
+ r = crypt_alloc_req(cc, ctx);
+ if (r) {
+ complete(&ctx->restart);
+ return BLK_STS_DEV_RESOURCE;
+ }
+
atomic_inc(&ctx->cc_pending);
if (crypt_integrity_aead(cc))
@@ -1553,7 +1574,25 @@ static blk_status_t crypt_convert(struct crypt_config *cc,
* but the driver request queue is full, let's wait.
*/
case -EBUSY:
- wait_for_completion(&ctx->restart);
+ if (in_interrupt()) {
+ if (try_wait_for_completion(&ctx->restart)) {
+ /*
+ * we don't have to block to wait for completion,
+ * so proceed
+ */
+ } else {
+ /*
+ * we can't wait for completion without blocking
+ * exit and continue processing in a workqueue
+ */
+ ctx->r.req = NULL;
+ ctx->cc_sector += sector_step;
+ tag_offset++;
+ return BLK_STS_DEV_RESOURCE;
+ }
+ } else {
+ wait_for_completion(&ctx->restart);
+ }
reinit_completion(&ctx->restart);
fallthrough;
/*
@@ -1691,6 +1730,12 @@ static void crypt_inc_pending(struct dm_crypt_io *io)
atomic_inc(&io->io_pending);
}
+static void kcryptd_io_bio_endio(struct work_struct *work)
+{
+ struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
+ bio_endio(io->base_bio);
+}
+
/*
* One of the bios was finished. Check for completion of
* the whole request and correctly clean up the buffer.
@@ -1713,7 +1758,23 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
kfree(io->integrity_metadata);
base_bio->bi_status = error;
- bio_endio(base_bio);
+
+ /*
+ * If we are running this function from our tasklet,
+ * we can't call bio_endio() here, because it will call
+ * clone_endio() from dm.c, which in turn will
+ * free the current struct dm_crypt_io structure with
+ * our tasklet. In this case we need to delay bio_endio()
+ * execution to after the tasklet is done and dequeued.
+ */
+ if (tasklet_trylock(&io->tasklet)) {
+ tasklet_unlock(&io->tasklet);
+ bio_endio(base_bio);
+ return;
+ }
+
+ INIT_WORK(&io->work, kcryptd_io_bio_endio);
+ queue_work(cc->io_queue, &io->work);
}
/*
@@ -1945,6 +2006,37 @@ static bool kcryptd_crypt_write_inline(struct crypt_config *cc,
}
}
+static void kcryptd_crypt_write_continue(struct work_struct *work)
+{
+ struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
+ struct crypt_config *cc = io->cc;
+ struct convert_context *ctx = &io->ctx;
+ int crypt_finished;
+ sector_t sector = io->sector;
+ blk_status_t r;
+
+ wait_for_completion(&ctx->restart);
+ reinit_completion(&ctx->restart);
+
+ r = crypt_convert(cc, &io->ctx, true, false);
+ if (r)
+ io->error = r;
+ 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) {
+ kcryptd_crypt_write_io_submit(io, 0);
+ io->sector = sector;
+ }
+
+ crypt_dec_pending(io);
+}
+
static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
{
struct crypt_config *cc = io->cc;
@@ -1973,7 +2065,17 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
crypt_inc_pending(io);
r = crypt_convert(cc, ctx,
- test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags));
+ test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags), true);
+ /*
+ * Crypto API backlogged the request, because its queue was full
+ * and we're in softirq context, so continue from a workqueue
+ * (TODO: is it actually possible to be in softirq in the write path?)
+ */
+ if (r == BLK_STS_DEV_RESOURCE) {
+ INIT_WORK(&io->work, kcryptd_crypt_write_continue);
+ queue_work(cc->crypt_queue, &io->work);
+ return;
+ }
if (r)
io->error = r;
crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
@@ -1998,6 +2100,25 @@ static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
crypt_dec_pending(io);
}
+static void kcryptd_crypt_read_continue(struct work_struct *work)
+{
+ struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
+ struct crypt_config *cc = io->cc;
+ blk_status_t r;
+
+ wait_for_completion(&io->ctx.restart);
+ reinit_completion(&io->ctx.restart);
+
+ r = crypt_convert(cc, &io->ctx, true, false);
+ if (r)
+ io->error = r;
+
+ if (atomic_dec_and_test(&io->ctx.cc_pending))
+ kcryptd_crypt_read_done(io);
+
+ crypt_dec_pending(io);
+}
+
static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
{
struct crypt_config *cc = io->cc;
@@ -2009,7 +2130,16 @@ static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
io->sector);
r = crypt_convert(cc, &io->ctx,
- test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags));
+ test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true);
+ /*
+ * Crypto API backlogged the request, because its queue was full
+ * and we're in softirq context, so continue from a workqueue
+ */
+ if (r == BLK_STS_DEV_RESOURCE) {
+ INIT_WORK(&io->work, kcryptd_crypt_read_continue);
+ queue_work(cc->crypt_queue, &io->work);
+ return;
+ }
if (r)
io->error = r;
@@ -2091,8 +2221,12 @@ static void kcryptd_queue_crypt(struct dm_crypt_io *io)
if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) ||
(bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) {
- if (in_irq()) {
- /* Crypto API's "skcipher_walk_first() refuses to work in hard IRQ context */
+ /*
+ * in_irq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context.
+ * irqs_disabled(): the kernel may run some IO completion from the idle thread, but
+ * it is being executed with irqs disabled.
+ */
+ if (in_irq() || irqs_disabled()) {
tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work);
tasklet_schedule(&io->tasklet);
return;