2 files changed, 40 insertions, 16 deletions

diff --git a/Documentation/device-mapper/dm-crypt.txt b/Documentation/device-mapper/dm-crypt.txt
index c81839b52c4d..571f24ffc91c 100644
--- a/Documentation/device-mapper/dm-crypt.txt
+++ b/Documentation/device-mapper/dm-crypt.txt
@@ -51,7 +51,7 @@ Parameters: <cipher> <key> <iv_offset> <device path> \
     Otherwise #opt_params is the number of following arguments.
 
     Example of optional parameters section:
-        1 allow_discards
+        2 allow_discards same_cpu_crypt
 
 allow_discards
     Block discard requests (a.k.a. TRIM) are passed through the crypt device.
@@ -63,6 +63,11 @@ allow_discards
     used space etc.) if the discarded blocks can be located easily on the
     device later.
 
+same_cpu_crypt
+    Perform encryption using the same cpu that IO was submitted on.
+    The default is to use an unbound workqueue so that encryption work
+    is automatically balanced between available CPUs.
+
 Example scripts
 ===============
 LUKS (Linux Unified Key Setup) is now the preferred way to set up disk
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 08981be7baa1..5063c901c0f5 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -108,7 +108,7 @@ struct iv_tcw_private {
  * Crypt: maps a linear range of a block device
  * and encrypts / decrypts at the same time.
  */
-enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
+enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, DM_CRYPT_SAME_CPU };
 
 /*
  * The fields in here must be read only after initialization.
@@ -1688,7 +1688,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         char dummy;
 
         static struct dm_arg _args[] = {
-                {0, 1, "Invalid number of feature args"},
+                {0, 2, "Invalid number of feature args"},
         };
 
         if (argc < 5) {
@@ -1788,15 +1788,23 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 if (ret)
                         goto bad;
 
-                opt_string = dm_shift_arg(&as);
+                while (opt_params--) {
+                        opt_string = dm_shift_arg(&as);
+                        if (!opt_string) {
+                                ti->error = "Not enough feature arguments";
+                                goto bad;
+                        }
 
-                if (opt_params == 1 && opt_string &&
-                    !strcasecmp(opt_string, "allow_discards"))
-                        ti->num_discard_bios = 1;
-                else if (opt_params) {
-                        ret = -EINVAL;
-                        ti->error = "Invalid feature arguments";
-                        goto bad;
+                        if (!strcasecmp(opt_string, "allow_discards"))
+                                ti->num_discard_bios = 1;
+
+                        else if (!strcasecmp(opt_string, "same_cpu_crypt"))
+                                set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
+
+                        else {
+                                ti->error = "Invalid feature arguments";
+                                goto bad;
+                        }
                 }
         }
 
@@ -1807,8 +1815,11 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 goto bad;
         }
 
-        cc->crypt_queue = alloc_workqueue("kcryptd",
-                                          WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
+        if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
+                cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
+        else
+                cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
+                                                  num_online_cpus());
         if (!cc->crypt_queue) {
                 ti->error = "Couldn't create kcryptd queue";
                 goto bad;
@@ -1860,6 +1871,7 @@ static void crypt_status(struct dm_target *ti, status_type_t type,
 {
         struct crypt_config *cc = ti->private;
         unsigned i, sz = 0;
+        int num_feature_args = 0;
 
         switch (type) {
         case STATUSTYPE_INFO:
@@ -1878,8 +1890,15 @@ static void crypt_status(struct dm_target *ti, status_type_t type,
                 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
                                 cc->dev->name, (unsigned long long)cc->start);
 
-                if (ti->num_discard_bios)
-                        DMEMIT(" 1 allow_discards");
+                num_feature_args += !!ti->num_discard_bios;
+                num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
+                if (num_feature_args) {
+                        DMEMIT(" %d", num_feature_args);
+                        if (ti->num_discard_bios)
+                                DMEMIT(" allow_discards");
+                        if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
+                                DMEMIT(" same_cpu_crypt");
+                }
 
                 break;
         }
@@ -1976,7 +1995,7 @@ static int crypt_iterate_devices(struct dm_target *ti,
 
 static struct target_type crypt_target = {
         .name   = "crypt",
-        .version = {1, 13, 0},
+        .version = {1, 14, 0},
         .module = THIS_MODULE,
         .ctr    = crypt_ctr,
         .dtr    = crypt_dtr,