* [dm-crypt] [PATCH v3 1/2] dm crypt: do not wait for backlogged crypto request completion in softirq
2021-01-04 14:59 [dm-crypt] [PATCH v3 0/2] dm crypt: some fixes to support dm-crypt running in softirq context Ignat Korchagin
@ 2021-01-04 14:59 ` Ignat Korchagin
2021-01-04 14:59 ` [dm-crypt] [PATCH v3 2/2] dm crypt: use GFP_ATOMIC when allocating crypto requests from softirq Ignat Korchagin
2021-01-04 17:04 ` [dm-crypt] [PATCH v3 0/2] dm crypt: some fixes to support dm-crypt running in softirq context Mikulas Patocka
2 siblings, 0 replies; 4+ messages in thread
From: Ignat Korchagin @ 2021-01-04 14:59 UTC (permalink / raw)
To: agk, snitzer, dm-devel, dm-crypt, linux-kernel
Cc: Damien.LeMoal, herbert, kernel-team, nobuto.murata, stable, josef,
ebiggers, clm, mpatocka, Ignat Korchagin, dsterba, mail,
linux-btrfs
Commit 39d42fa96ba1b7d2544db3f8ed5da8fb0d5cb877 made it possible for some code
paths in dm-crypt to be executed in softirq context, when the underlying driver
processes IO requests in interrupt/softirq context.
When Crypto API backlogs a crypto request, dm-crypt uses wait_for_completion to
avoid sending further requests to an already overloaded crypto driver. However,
if the code is executing in softirq context, we might get the following
stacktrace:
[ 210.235213][ C0] BUG: scheduling while atomic: fio/2602/0x00000102
[ 210.236701][ C0] Modules linked in:
[ 210.237566][ C0] CPU: 0 PID: 2602 Comm: fio Tainted: G W 5.10.0+ #50
[ 210.239292][ C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
[ 210.241233][ C0] Call Trace:
[ 210.241946][ C0] <IRQ>
[ 210.242561][ C0] dump_stack+0x7d/0xa3
[ 210.243466][ C0] __schedule_bug.cold+0xb3/0xc2
[ 210.244539][ C0] __schedule+0x156f/0x20d0
[ 210.245518][ C0] ? io_schedule_timeout+0x140/0x140
[ 210.246660][ C0] schedule+0xd0/0x270
[ 210.247541][ C0] schedule_timeout+0x1fb/0x280
[ 210.248586][ C0] ? usleep_range+0x150/0x150
[ 210.249624][ C0] ? unpoison_range+0x3a/0x60
[ 210.250632][ C0] ? ____kasan_kmalloc.constprop.0+0x82/0xa0
[ 210.251949][ C0] ? unpoison_range+0x3a/0x60
[ 210.252958][ C0] ? __prepare_to_swait+0xa7/0x190
[ 210.254067][ C0] do_wait_for_common+0x2ab/0x370
[ 210.255158][ C0] ? usleep_range+0x150/0x150
[ 210.256192][ C0] ? bit_wait_io_timeout+0x160/0x160
[ 210.257358][ C0] ? blk_update_request+0x757/0x1150
[ 210.258582][ C0] ? _raw_spin_lock_irq+0x82/0xd0
[ 210.259674][ C0] ? _raw_read_unlock_irqrestore+0x30/0x30
[ 210.260917][ C0] wait_for_completion+0x4c/0x90
[ 210.261971][ C0] crypt_convert+0x19a6/0x4c00
[ 210.263033][ C0] ? _raw_spin_lock_irqsave+0x87/0xe0
[ 210.264193][ C0] ? kasan_set_track+0x1c/0x30
[ 210.265191][ C0] ? crypt_iv_tcw_ctr+0x4a0/0x4a0
[ 210.266283][ C0] ? kmem_cache_free+0x104/0x470
[ 210.267363][ C0] ? crypt_endio+0x91/0x180
[ 210.268327][ C0] kcryptd_crypt_read_convert+0x30e/0x420
[ 210.269565][ C0] blk_update_request+0x757/0x1150
[ 210.270563][ C0] blk_mq_end_request+0x4b/0x480
[ 210.271680][ C0] blk_done_softirq+0x21d/0x340
[ 210.272775][ C0] ? _raw_spin_lock+0x81/0xd0
[ 210.273847][ C0] ? blk_mq_stop_hw_queue+0x30/0x30
[ 210.275031][ C0] ? _raw_read_lock_irq+0x40/0x40
[ 210.276182][ C0] __do_softirq+0x190/0x611
[ 210.277203][ C0] ? handle_edge_irq+0x221/0xb60
[ 210.278340][ C0] asm_call_irq_on_stack+0x12/0x20
[ 210.279514][ C0] </IRQ>
[ 210.280164][ C0] do_softirq_own_stack+0x37/0x40
[ 210.281281][ C0] irq_exit_rcu+0x110/0x1b0
[ 210.282286][ C0] common_interrupt+0x74/0x120
[ 210.283376][ C0] asm_common_interrupt+0x1e/0x40
[ 210.284496][ C0] RIP: 0010:_aesni_enc1+0x65/0xb0
Fix this by making crypt_convert function reentrant from the point of a single
bio and make dm-crypt defer further bio processing to a workqueue, if Crypto API
backlogs a request in interrupt context.
Fixes: 39d42fa96ba1 ("dm crypt: add flags to optionally bypass kcryptd workq
ueues")
Cc: <stable@vger.kernel.org> # v5.9+
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
---
drivers/md/dm-crypt.c | 103 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 98 insertions(+), 5 deletions(-)
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 392337f16ecf..a3326dadfd4d 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1529,13 +1529,19 @@ 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) {
@@ -1553,7 +1559,25 @@ 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;
/*
@@ -1945,6 +1969,37 @@ 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 +2028,17 @@ 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 +2063,25 @@ 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 +2093,16 @@ 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;
--
2.20.1
_______________________________________________
dm-crypt mailing list
dm-crypt@saout.de
https://www.saout.de/mailman/listinfo/dm-crypt
^ permalink raw reply related [flat|nested] 4+ messages in thread* [dm-crypt] [PATCH v3 2/2] dm crypt: use GFP_ATOMIC when allocating crypto requests from softirq
2021-01-04 14:59 [dm-crypt] [PATCH v3 0/2] dm crypt: some fixes to support dm-crypt running in softirq context Ignat Korchagin
2021-01-04 14:59 ` [dm-crypt] [PATCH v3 1/2] dm crypt: do not wait for backlogged crypto request completion in softirq Ignat Korchagin
@ 2021-01-04 14:59 ` Ignat Korchagin
2021-01-04 17:04 ` [dm-crypt] [PATCH v3 0/2] dm crypt: some fixes to support dm-crypt running in softirq context Mikulas Patocka
2 siblings, 0 replies; 4+ messages in thread
From: Ignat Korchagin @ 2021-01-04 14:59 UTC (permalink / raw)
To: agk, snitzer, dm-devel, dm-crypt, linux-kernel
Cc: Damien.LeMoal, herbert, kernel-team, nobuto.murata, stable, josef,
ebiggers, clm, mpatocka, Ignat Korchagin, dsterba, mail,
linux-btrfs
Commit 39d42fa96ba1b7d2544db3f8ed5da8fb0d5cb877 made it possible for some code
paths in dm-crypt to be executed in softirq context, when the underlying driver
processes IO requests in interrupt/softirq context.
In this case sometimes when allocating a new crypto request we may get a
stacktrace like below:
[ 210.103008][ C0] BUG: sleeping function called from invalid context at mm/mempool.c:381
[ 210.104746][ C0] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2602, name: fio
[ 210.106599][ C0] CPU: 0 PID: 2602 Comm: fio Tainted: G W 5.10.0+ #50
[ 210.108331][ C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
[ 210.110212][ C0] Call Trace:
[ 210.110921][ C0] <IRQ>
[ 210.111527][ C0] dump_stack+0x7d/0xa3
[ 210.112411][ C0] ___might_sleep.cold+0x122/0x151
[ 210.113527][ C0] mempool_alloc+0x16b/0x2f0
[ 210.114524][ C0] ? __queue_work+0x515/0xde0
[ 210.115553][ C0] ? mempool_resize+0x700/0x700
[ 210.116586][ C0] ? crypt_endio+0x91/0x180
[ 210.117479][ C0] ? blk_update_request+0x757/0x1150
[ 210.118513][ C0] ? blk_mq_end_request+0x4b/0x480
[ 210.119572][ C0] ? blk_done_softirq+0x21d/0x340
[ 210.120628][ C0] ? __do_softirq+0x190/0x611
[ 210.121626][ C0] crypt_convert+0x29f9/0x4c00
[ 210.122668][ C0] ? _raw_spin_lock_irqsave+0x87/0xe0
[ 210.123824][ C0] ? kasan_set_track+0x1c/0x30
[ 210.124858][ C0] ? crypt_iv_tcw_ctr+0x4a0/0x4a0
[ 210.125930][ C0] ? kmem_cache_free+0x104/0x470
[ 210.126973][ C0] ? crypt_endio+0x91/0x180
[ 210.127947][ C0] kcryptd_crypt_read_convert+0x30e/0x420
[ 210.129165][ C0] blk_update_request+0x757/0x1150
[ 210.130231][ C0] blk_mq_end_request+0x4b/0x480
[ 210.131294][ C0] blk_done_softirq+0x21d/0x340
[ 210.132332][ C0] ? _raw_spin_lock+0x81/0xd0
[ 210.133289][ C0] ? blk_mq_stop_hw_queue+0x30/0x30
[ 210.134399][ C0] ? _raw_read_lock_irq+0x40/0x40
[ 210.135458][ C0] __do_softirq+0x190/0x611
[ 210.136409][ C0] ? handle_edge_irq+0x221/0xb60
[ 210.137447][ C0] asm_call_irq_on_stack+0x12/0x20
[ 210.138507][ C0] </IRQ>
[ 210.139118][ C0] do_softirq_own_stack+0x37/0x40
[ 210.140191][ C0] irq_exit_rcu+0x110/0x1b0
[ 210.141151][ C0] common_interrupt+0x74/0x120
[ 210.142171][ C0] asm_common_interrupt+0x1e/0x40
[ 210.143206][ C0] RIP: 0010:_aesni_enc1+0x65/0xb0
[ 210.144313][ C0] Code: 38 dc c2 41 0f 28 52 d0 66 0f 38 dc c2 41 0f 28 52 e0 66 0f 38 dc c2 41 0f 28 52 f0 66 0f 38 dc c2 41 0f 28 12 66 0f 38 dc c2 <41> 0f 28 52 10 66 0f 38 dc c2 41 0f 28 52 20 66 0f 38 dc c2 41 0f
[ 210.148542][ C0] RSP: 0018:ffff88810dbe6db0 EFLAGS: 00000286
[ 210.149842][ C0] RAX: ffffffff9a90cdc0 RBX: 0000000000000000 RCX: 0000000000000200
[ 210.151576][ C0] RDX: ffff888101e5f240 RSI: ffff888101e5f240 RDI: ffff8881111b5020
[ 210.153339][ C0] RBP: ffff88810dbe6e20 R08: 0000000000000000 R09: 0000000000000020
[ 210.155063][ C0] R10: ffff8881111b5090 R11: 1ffff11021b7cdcc R12: ffffffff9e87cd40
[ 210.156791][ C0] R13: ffff8881111b5210 R14: ffff888101e5f0d8 R15: 0000000000000000
[ 210.158497][ C0] ? aesni_set_key+0x1e0/0x1e0
[ 210.159523][ C0] ? aesni_enc+0xf/0x20
[ 210.160408][ C0] ? glue_xts_req_128bit+0x181/0x6f0
[ 210.161571][ C0] ? aesni_set_key+0x1e0/0x1e0
[ 210.162560][ C0] ? glue_ctr_req_128bit+0x630/0x630
[ 210.163706][ C0] ? kasan_save_stack+0x37/0x50
[ 210.164761][ C0] ? kasan_save_stack+0x20/0x50
[ 210.165786][ C0] ? get_page_from_freelist+0x2052/0x36a0
[ 210.167024][ C0] ? __blkdev_direct_IO_simple+0x43b/0x7e0
[ 210.168288][ C0] ? blkdev_direct_IO+0xd16/0x1020
[ 210.169396][ C0] ? generic_file_direct_write+0x1a3/0x480
[ 210.170648][ C0] ? __generic_file_write_iter+0x1d9/0x530
[ 210.171882][ C0] ? blkdev_write_iter+0x20d/0x3e0
[ 210.172954][ C0] ? vfs_write+0x524/0x770
[ 210.173889][ C0] ? do_syscall_64+0x33/0x40
[ 210.174859][ C0] ? __zone_watermark_ok+0x340/0x340
[ 210.175977][ C0] ? crypt_convert+0x28b6/0x4c00
[ 210.177079][ C0] ? mempool_alloc+0x107/0x2f0
[ 210.178096][ C0] ? crypt_iv_tcw_ctr+0x4a0/0x4a0
[ 210.179193][ C0] ? bio_add_page+0x111/0x170
[ 210.180251][ C0] ? __bio_try_merge_page+0x480/0x480
[ 210.181446][ C0] ? bio_associate_blkg+0x6d/0x100
[ 210.182558][ C0] ? kcryptd_crypt_write_convert+0x5ea/0x980
[ 210.183852][ C0] ? crypt_map+0x5bf/0xc80
[ 210.184838][ C0] ? bio_clone_blkg_association+0x10e/0x2c0
[ 210.186125][ C0] ? __map_bio.isra.0+0x109/0x3f0
[ 210.187204][ C0] ? __split_and_process_non_flush+0x7f9/0xc50
[ 210.188560][ C0] ? __send_empty_flush+0x2d0/0x2d0
[ 210.189697][ C0] ? __part_start_io_acct+0x70/0x2d0
[ 210.190842][ C0] ? dm_submit_bio+0x4d8/0xe40
[ 210.191845][ C0] ? __split_and_process_non_flush+0xc50/0xc50
[ 210.193201][ C0] ? submit_bio_noacct+0x2b9/0xe50
[ 210.194313][ C0] ? blk_queue_enter+0x6d0/0x6d0
[ 210.195372][ C0] ? __bio_add_page+0x246/0x3d0
[ 210.196418][ C0] ? bio_iov_iter_get_pages+0x7dd/0xbe0
[ 210.197611][ C0] ? submit_bio+0xe2/0x460
[ 210.198481][ C0] ? submit_bio_noacct+0xe50/0xe50
[ 210.199496][ C0] ? free_unref_page_commit.constprop.0+0x130/0x330
[ 210.200825][ C0] ? __blkdev_direct_IO_simple+0x43b/0x7e0
[ 210.202050][ C0] ? bd_link_disk_holder+0x690/0x690
[ 210.203239][ C0] ? put_pages_list+0x210/0x210
[ 210.204341][ C0] ? scan_shadow_nodes+0xb0/0xb0
[ 210.205472][ C0] ? _raw_write_lock_irqsave+0xe0/0xe0
[ 210.206698][ C0] ? bd_may_claim+0xc0/0xc0
[ 210.207715][ C0] ? zero_user_segments.constprop.0+0x2e0/0x2e0
[ 210.209092][ C0] ? blkdev_direct_IO+0xd16/0x1020
[ 210.210200][ C0] ? pagevec_lookup_range_tag+0x28/0x60
[ 210.211416][ C0] ? __filemap_fdatawait_range+0xc4/0x1f0
[ 210.212669][ C0] ? page_cache_next_miss+0x1e0/0x1e0
[ 210.213842][ C0] ? generic_file_buffered_read+0x520/0x9e0
[ 210.215128][ C0] ? delete_from_page_cache_batch+0x850/0x850
[ 210.216470][ C0] ? bd_abort_claiming+0xd0/0xd0
[ 210.217531][ C0] ? file_remove_privs+0x74/0x430
[ 210.218589][ C0] ? filemap_check_errors+0x50/0xe0
[ 210.219705][ C0] ? generic_file_direct_write+0x1a3/0x480
[ 210.220979][ C0] ? __generic_file_write_iter+0x1d9/0x530
[ 210.222238][ C0] ? blkdev_write_iter+0x20d/0x3e0
[ 210.223328][ C0] ? bd_unlink_disk_holder+0x360/0x360
[ 210.224464][ C0] ? new_sync_write+0x37b/0x620
[ 210.225511][ C0] ? new_sync_read+0x610/0x610
[ 210.226539][ C0] ? _cond_resched+0x17/0x80
[ 210.227539][ C0] ? inode_security+0x58/0x100
[ 210.228582][ C0] ? security_file_permission+0x54/0x450
[ 210.229796][ C0] ? vfs_write+0x524/0x770
[ 210.230758][ C0] ? __x64_sys_pwrite64+0x197/0x1f0
[ 210.231890][ C0] ? vfs_write+0x770/0x770
[ 210.232869][ C0] ? do_syscall_64+0x33/0x40
[ 210.233839][ C0] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fix this by allocating crypto requests with GFP_ATOMIC mask in interrupt context
Fixes: 39d42fa96ba1 ("dm crypt: add flags to optionally bypass kcryptd workqueues")
Reported-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Cc: <stable@vger.kernel.org> # v5.9+
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
---
drivers/md/dm-crypt.c | 35 +++++++++++++++++++++++++----------
1 file changed, 25 insertions(+), 10 deletions(-)
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index a3326dadfd4d..1f471dd75144 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) {
+ ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
+ if (!ctx->r.req)
+ 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,
@@ -1545,7 +1555,12 @@ static blk_status_t crypt_convert(struct crypt_config *cc,
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))
--
2.20.1
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^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [dm-crypt] [PATCH v3 0/2] dm crypt: some fixes to support dm-crypt running in softirq context
2021-01-04 14:59 [dm-crypt] [PATCH v3 0/2] dm crypt: some fixes to support dm-crypt running in softirq context Ignat Korchagin
2021-01-04 14:59 ` [dm-crypt] [PATCH v3 1/2] dm crypt: do not wait for backlogged crypto request completion in softirq Ignat Korchagin
2021-01-04 14:59 ` [dm-crypt] [PATCH v3 2/2] dm crypt: use GFP_ATOMIC when allocating crypto requests from softirq Ignat Korchagin
@ 2021-01-04 17:04 ` Mikulas Patocka
2 siblings, 0 replies; 4+ messages in thread
From: Mikulas Patocka @ 2021-01-04 17:04 UTC (permalink / raw)
To: Ignat Korchagin
Cc: Damien.LeMoal, herbert, snitzer, kernel-team, dm-crypt,
linux-kernel, nobuto.murata, ebiggers, clm, dm-devel, linux-btrfs,
dsterba, josef, mail, agk
On Mon, 4 Jan 2021, Ignat Korchagin wrote:
> Changes from v1:
> * 0001: handle memory allocation failure for GFP_ATOMIC
>
> Changes from v2:
> * reordered patches
> * 0002: crypt_convert will be retried from a workqueue, when a crypto request
> allocation fails with GFP_ATOMIC instead of just returning an IO error to
> the user
>
> Ignat Korchagin (2):
> dm crypt: do not wait for backlogged crypto request completion in
> softirq
> dm crypt: use GFP_ATOMIC when allocating crypto requests from softirq
>
> drivers/md/dm-crypt.c | 138 +++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 123 insertions(+), 15 deletions(-)
>
> --
> 2.20.1
>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
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^ permalink raw reply [flat|nested] 4+ messages in thread