diff options
Diffstat (limited to 'kernel/drivers/md/dm-crypt.c')
| -rw-r--r-- | kernel/drivers/md/dm-crypt.c | 111 |
1 files changed, 65 insertions, 46 deletions
diff --git a/kernel/drivers/md/dm-crypt.c b/kernel/drivers/md/dm-crypt.c index 5503e43e5..3147c8d09 100644 --- a/kernel/drivers/md/dm-crypt.c +++ b/kernel/drivers/md/dm-crypt.c @@ -1,7 +1,7 @@ /* * Copyright (C) 2003 Jana Saout <jana@saout.de> * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> - * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved. + * Copyright (C) 2006-2015 Red Hat, Inc. All rights reserved. * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com> * * This file is released under the GPL. @@ -112,7 +112,8 @@ struct iv_tcw_private { * and encrypts / decrypts at the same time. */ enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, - DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD }; + DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD, + DM_CRYPT_EXIT_THREAD}; /* * The fields in here must be read only after initialization. @@ -891,6 +892,11 @@ static void crypt_alloc_req(struct crypt_config *cc, ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO); ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]); + + /* + * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs + * requests if driver request queue is full. + */ ablkcipher_request_set_callback(ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, kcryptd_async_done, dmreq_of_req(cc, ctx->req)); @@ -924,24 +930,32 @@ static int crypt_convert(struct crypt_config *cc, r = crypt_convert_block(cc, ctx, ctx->req); switch (r) { - /* async */ + /* + * The request was queued by a crypto driver + * but the driver request queue is full, let's wait. + */ case -EBUSY: wait_for_completion(&ctx->restart); reinit_completion(&ctx->restart); - /* fall through*/ + /* fall through */ + /* + * The request is queued and processed asynchronously, + * completion function kcryptd_async_done() will be called. + */ case -EINPROGRESS: ctx->req = NULL; ctx->cc_sector++; continue; - - /* sync */ + /* + * The request was already processed (synchronously). + */ case 0: atomic_dec(&ctx->cc_pending); ctx->cc_sector++; cond_resched(); continue; - /* error */ + /* There was an error while processing the request. */ default: atomic_dec(&ctx->cc_pending); return r; @@ -955,7 +969,8 @@ static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); /* * Generate a new unfragmented bio with the given size - * This should never violate the device limitations + * This should never violate the device limitations (but only because + * max_segment_size is being constrained to PAGE_SIZE). * * This function may be called concurrently. If we allocate from the mempool * concurrently, there is a possibility of deadlock. For example, if we have @@ -980,7 +995,7 @@ static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) struct bio_vec *bvec; retry: - if (unlikely(gfp_mask & __GFP_WAIT)) + if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) mutex_lock(&cc->bio_alloc_lock); clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); @@ -996,7 +1011,7 @@ retry: if (!page) { crypt_free_buffer_pages(cc, clone); bio_put(clone); - gfp_mask |= __GFP_WAIT; + gfp_mask |= __GFP_DIRECT_RECLAIM; goto retry; } @@ -1013,7 +1028,7 @@ retry: } return_clone: - if (unlikely(gfp_mask & __GFP_WAIT)) + if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) mutex_unlock(&cc->bio_alloc_lock); return clone; @@ -1063,7 +1078,8 @@ static void crypt_dec_pending(struct dm_crypt_io *io) if (io->ctx.req) crypt_free_req(cc, io->ctx.req, base_bio); - bio_endio(base_bio, error); + base_bio->bi_error = error; + bio_endio(base_bio); } /* @@ -1083,14 +1099,12 @@ static void crypt_dec_pending(struct dm_crypt_io *io) * The work is done per CPU global for all dm-crypt instances. * They should not depend on each other and do not block. */ -static void crypt_endio(struct bio *clone, int error) +static void crypt_endio(struct bio *clone) { struct dm_crypt_io *io = clone->bi_private; struct crypt_config *cc = io->cc; unsigned rw = bio_data_dir(clone); - - if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error)) - error = -EIO; + int error; /* * free the processed pages @@ -1098,6 +1112,7 @@ static void crypt_endio(struct bio *clone, int error) if (rw == WRITE) crypt_free_buffer_pages(cc, clone); + error = clone->bi_error; bio_put(clone); if (rw == READ && !error) { @@ -1189,20 +1204,18 @@ continue_locked: if (!RB_EMPTY_ROOT(&cc->write_tree)) goto pop_from_list; + if (unlikely(test_bit(DM_CRYPT_EXIT_THREAD, &cc->flags))) { + spin_unlock_irq(&cc->write_thread_wait.lock); + break; + } + __set_current_state(TASK_INTERRUPTIBLE); __add_wait_queue(&cc->write_thread_wait, &wait); spin_unlock_irq(&cc->write_thread_wait.lock); - if (unlikely(kthread_should_stop())) { - set_task_state(current, TASK_RUNNING); - remove_wait_queue(&cc->write_thread_wait, &wait); - break; - } - schedule(); - set_task_state(current, TASK_RUNNING); spin_lock_irq(&cc->write_thread_wait.lock); __remove_wait_queue(&cc->write_thread_wait, &wait); goto continue_locked; @@ -1346,6 +1359,11 @@ static void kcryptd_async_done(struct crypto_async_request *async_req, struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); struct crypt_config *cc = io->cc; + /* + * A request from crypto driver backlog is going to be processed now, + * finish the completion and continue in crypt_convert(). + * (Callback will be called for the second time for this request.) + */ if (error == -EINPROGRESS) { complete(&ctx->restart); return; @@ -1512,8 +1530,13 @@ static void crypt_dtr(struct dm_target *ti) if (!cc) return; - if (cc->write_thread) + if (cc->write_thread) { + spin_lock_irq(&cc->write_thread_wait.lock); + set_bit(DM_CRYPT_EXIT_THREAD, &cc->flags); + wake_up_locked(&cc->write_thread_wait); + spin_unlock_irq(&cc->write_thread_wait.lock); kthread_stop(cc->write_thread); + } if (cc->io_queue) destroy_workqueue(cc->io_queue); @@ -1525,10 +1548,8 @@ static void crypt_dtr(struct dm_target *ti) if (cc->bs) bioset_free(cc->bs); - if (cc->page_pool) - mempool_destroy(cc->page_pool); - if (cc->req_pool) - mempool_destroy(cc->req_pool); + mempool_destroy(cc->page_pool); + mempool_destroy(cc->req_pool); if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) cc->iv_gen_ops->dtr(cc); @@ -1793,11 +1814,13 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) } cc->iv_offset = tmpll; - if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) { + ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev); + if (ret) { ti->error = "Device lookup failed"; goto bad; } + ret = -EINVAL; if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) { ti->error = "Invalid device sector"; goto bad; @@ -2017,21 +2040,6 @@ error: return -EINVAL; } -static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm, - struct bio_vec *biovec, int max_size) -{ - struct crypt_config *cc = ti->private; - struct request_queue *q = bdev_get_queue(cc->dev->bdev); - - if (!q->merge_bvec_fn) - return max_size; - - bvm->bi_bdev = cc->dev->bdev; - bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector); - - return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); -} - static int crypt_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data) { @@ -2040,9 +2048,20 @@ static int crypt_iterate_devices(struct dm_target *ti, return fn(ti, cc->dev, cc->start, ti->len, data); } +static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) +{ + /* + * Unfortunate constraint that is required to avoid the potential + * for exceeding underlying device's max_segments limits -- due to + * crypt_alloc_buffer() possibly allocating pages for the encryption + * bio that are not as physically contiguous as the original bio. + */ + limits->max_segment_size = PAGE_SIZE; +} + static struct target_type crypt_target = { .name = "crypt", - .version = {1, 14, 0}, + .version = {1, 14, 1}, .module = THIS_MODULE, .ctr = crypt_ctr, .dtr = crypt_dtr, @@ -2052,8 +2071,8 @@ static struct target_type crypt_target = { .preresume = crypt_preresume, .resume = crypt_resume, .message = crypt_message, - .merge = crypt_merge, .iterate_devices = crypt_iterate_devices, + .io_hints = crypt_io_hints, }; static int __init dm_crypt_init(void) |