Commit 2285e149 authored by yangerkun's avatar yangerkun Committed by Mike Snitzer
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dm-crypt: export sysfs of all workqueues 



Once there is a heavy IO load, so many encrypt/decrypt work will occupy
all of the cpu, which may lead to the poor performance for other service.
So the improved visibility and controls over dm-crypt workqueues, as
was offered with commit a2b8b2d9 ("dm crypt: export sysfs of
kcryptd workqueue"), seems necessary. By exporting dm-crypt's
workqueues in sysfs, the entry like cpumask/max_active and so on can
help us to limit the CPU usage for encrypt/decrypt work.

However, commit a2b8b2d9 did not consider that DM table reload
will call .ctr before .dtr, so the reload for dm-crypt failed because
the same sysfs name was present. This was the original need for commit
48b0777c ("Revert "dm crypt: export sysfs of kcryptd workqueue"").

Reintroduce the use of WQ_SYSFS, and use it for both the IO and crypt
workqueues, but make the workqueue names include a unique id (via ida)
to allow both old and new sysfs entries to coexist.

Signed-off-by: default avataryangerkun <yangerkun@huawei.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarMike Snitzer <snitzer@kernel.org>
parent 5268de78

drivers/md/dm-crypt.c

+21 −7
Original line number Diff line number Diff line
@@ -47,6 +47,8 @@ 


#define DM_MSG_PREFIX "crypt"



static DEFINE_IDA(workqueue_ida);



/*

 * context holding the current state of a multi-part conversion

 */
@@ -184,6 +186,7 @@ struct crypt_config { 
		struct crypto_aead **tfms_aead;

	} cipher_tfm;

	unsigned int tfms_count;

	int workqueue_id;

	unsigned long cipher_flags;



	/*
@@ -2771,6 +2774,9 @@ static void crypt_dtr(struct dm_target *ti) 
	if (cc->crypt_queue)

		destroy_workqueue(cc->crypt_queue);



	if (cc->workqueue_id)

		ida_free(&workqueue_ida, cc->workqueue_id);



	crypt_free_tfms(cc);



	bioset_exit(&cc->bs);
@@ -3232,7 +3238,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
{

	struct crypt_config *cc;

	const char *devname = dm_table_device_name(ti->table);

	int key_size;

	int key_size, wq_id;

	unsigned int align_mask;

	unsigned int common_wq_flags;

	unsigned long long tmpll;
@@ -3401,25 +3407,33 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
		cc->tag_pool_max_sectors <<= cc->sector_shift;

	}



	wq_id = ida_alloc_min(&workqueue_ida, 1, GFP_KERNEL);

	if (wq_id < 0) {

		ti->error = "Couldn't get workqueue id";

		ret = wq_id;

		goto bad;

	}

	cc->workqueue_id = wq_id;



	ret = -ENOMEM;

	common_wq_flags = WQ_MEM_RECLAIM;

	common_wq_flags = WQ_MEM_RECLAIM | WQ_SYSFS;

	if (test_bit(DM_CRYPT_HIGH_PRIORITY, &cc->flags))

		common_wq_flags |= WQ_HIGHPRI;



	cc->io_queue = alloc_workqueue("kcryptd_io/%s", common_wq_flags, 1, devname);

	cc->io_queue = alloc_workqueue("kcryptd_io-%s-%d", common_wq_flags, 1, devname, wq_id);

	if (!cc->io_queue) {

		ti->error = "Couldn't create kcryptd io queue";

		goto bad;

	}



	if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) {

		cc->crypt_queue = alloc_workqueue("kcryptd/%s",

		cc->crypt_queue = alloc_workqueue("kcryptd-%s-%d",

						  common_wq_flags | WQ_CPU_INTENSIVE,

						  1, devname);

						  1, devname, wq_id);

	} else {

		cc->crypt_queue = alloc_workqueue("kcryptd/%s",

		cc->crypt_queue = alloc_workqueue("kcryptd-%s-%d",

						  common_wq_flags | WQ_CPU_INTENSIVE | WQ_UNBOUND,

						  num_online_cpus(), devname);

						  num_online_cpus(), devname, wq_id);

	}

	if (!cc->crypt_queue) {

		ti->error = "Couldn't create kcryptd queue";