[dm-devel] [PATCH] dm-crypt: reexport sysfs of kcryptd workqueue

[yangerkun]

From: yangerkun <yangerkun at huawei.com>

'a2b8b2d97567 ("dm crypt: export sysfs of kcryptd workqueue")' give us
idea to set specific CPU or limit max_active crypt work. However sysfs
will report a warnning and fail 'cryptsetup refresh test' since the
reload will alloc workqueue with same sysfs name, and we temporarily
revert this feature to fix the problem.

What we actually should do is give a unique name once we try reload
table, we can use ida now.

Signed-off-by: yangerkun <yangerkun at huawei.com>
---
 drivers/md/dm-crypt.c | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 755a01d72cdb..f0b8cb4364a1 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -46,6 +46,8 @@
 
 #define DM_MSG_PREFIX "crypt"
 
+static DEFINE_IDA(crypt_queue_ida);
+
 /*
  * context holding the current state of a multi-part conversion
  */
@@ -179,6 +181,7 @@ struct crypt_config {
 		struct crypto_aead **tfms_aead;
 	} cipher_tfm;
 	unsigned tfms_count;
+	int crypt_queue_id;
 	unsigned long cipher_flags;
 
 	/*
@@ -2708,6 +2711,9 @@ static void crypt_dtr(struct dm_target *ti)
 	if (cc->crypt_queue)
 		destroy_workqueue(cc->crypt_queue);
 
+	if (cc->crypt_queue_id)
+		ida_free(&crypt_queue_ida, cc->crypt_queue_id);
+
 	crypt_free_tfms(cc);
 
 	bioset_exit(&cc->bs);
@@ -3344,12 +3350,24 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	}
 
 	if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
-		cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
+		cc->crypt_queue = alloc_workqueue("kcryptd-%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
 						  1, devname);
-	else
-		cc->crypt_queue = alloc_workqueue("kcryptd/%s",
-						  WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
-						  num_online_cpus(), devname);
+	else {
+		int id = ida_alloc_min(&crypt_queue_ida, 1, GFP_KERNEL);
+
+		if (id < 0) {
+			ti->error = "Couldn't get kcryptd queue id";
+			ret = id;
+			goto bad;
+		}
+
+		cc->crypt_queue_id = id;
+		cc->crypt_queue = alloc_workqueue("kcryptd-%s-%d",
+						  WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM |
+						  WQ_UNBOUND | WQ_SYSFS,
+						  num_online_cpus(), devname, id);
+	}
+
 	if (!cc->crypt_queue) {
 		ti->error = "Couldn't create kcryptd queue";
 		goto bad;
-- 
2.31.1