[PATCH v2 0/5] padata lockdep, cpumask, and doc fixes

[PATCH v2 0/5] padata lockdep, cpumask, and doc fixes

[Daniel Jordan]

This series depends on all of Herbert's recent padata fixes to reduce
merge conflicts on his end:

  crypto: pcrypt - Do not clear MAY_SLEEP flag in original request
  padata: Remove unused padata_remove_cpu
  [v3] crypto: pcrypt - Avoid deadlock by using per-instance padata queues
  crypto: pcrypt - Fix user-after-free on module unload
  padata: Remove broken queue flushing 

If this should be based on something else, please let me know.

Thanks,
Daniel

v2:
 - documentation patch RST-ized according to Jon's comments
 - "validate cpumask" patch added
 - rebased onto v5.4 and updated since Herbert's fixes have changed

Daniel Jordan (5):
  padata: validate cpumask without removed CPU during offline
  padata: always acquire cpu_hotplug_lock before pinst->lock
  padata: remove cpumask change notifier
  padata: remove reorder_objects
  padata: update documentation

 Documentation/core-api/index.rst  |   1 +
 Documentation/core-api/padata.rst | 169 ++++++++++++++++++++++++++++++
 Documentation/padata.txt          | 163 ----------------------------
 crypto/pcrypt.c                   |   1 -
 include/linux/cpuhotplug.h        |   1 +
 include/linux/padata.h            |  28 ++---
 kernel/padata.c                   | 124 ++++++++--------------
 7 files changed, 220 insertions(+), 267 deletions(-)
 create mode 100644 Documentation/core-api/padata.rst
 delete mode 100644 Documentation/padata.txt


base-commit: 219d54332a09e8d8741c1e1982f5eae56099de85
prerequisite-patch-id: e31e7b28eb12a2c7e1e04261f4e890f83a57bd19
prerequisite-patch-id: 00f7ca687bd9df6281e9ced0925a865b2fa7b297
prerequisite-patch-id: 9f3bb985b34d29ff30e44b8829545736de02186f
prerequisite-patch-id: fe09ee84131ee649b90ee291fbbeda32e90c42fe
prerequisite-patch-id: f2e5a29f78e2403677ad50d870d90022932bc2b6
-- 
2.24.0

[PATCH v2 1/5] padata: validate cpumask without removed CPU during offline

[Daniel Jordan]

Configuring an instance's parallel mask without any online CPUs...

  echo 2 > /sys/kernel/pcrypt/pencrypt/parallel_cpumask
  echo 0 > /sys/devices/system/cpu/cpu1/online

...makes tcrypt mode=215 crash like this:

  divide error: 0000 [#1] SMP PTI
  CPU: 4 PID: 283 Comm: modprobe Not tainted 5.4.0-rc8-padata-doc-v2+ #2
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191013_105130-anatol 04/01/2014
  RIP: 0010:padata_do_parallel+0x114/0x300
  Call Trace:
   pcrypt_aead_encrypt+0xc0/0xd0 [pcrypt]
   crypto_aead_encrypt+0x1f/0x30
   do_mult_aead_op+0x4e/0xdf [tcrypt]
   test_mb_aead_speed.constprop.0.cold+0x226/0x564 [tcrypt]
   do_test+0x28c2/0x4d49 [tcrypt]
   tcrypt_mod_init+0x55/0x1000 [tcrypt]
   ...

cpumask_weight() in padata_cpu_hash() returns 0 because the mask has no
CPUs.  The problem is __padata_remove_cpu() checks for valid masks too
early and so doesn't mark the instance PADATA_INVALID as expected, which
would have made padata_do_parallel() return error before doing the
division.

Fix by introducing a second padata CPU hotplug state before
CPUHP_BRINGUP_CPU so that __padata_remove_cpu() sees the online mask
without @cpu.  No need for the second argument to padata_replace() since
@cpu is now already missing from the online mask.

Fixes: 33e54450683c ("padata: Handle empty padata cpumasks")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 include/linux/cpuhotplug.h |  1 +
 kernel/padata.c            | 30 ++++++++++++++++++------------
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 068793a619ca..2d55cee638fc 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -59,6 +59,7 @@ enum cpuhp_state {
 	CPUHP_IOMMU_INTEL_DEAD,
 	CPUHP_LUSTRE_CFS_DEAD,
 	CPUHP_AP_ARM_CACHE_B15_RAC_DEAD,
+	CPUHP_PADATA_DEAD,
 	CPUHP_WORKQUEUE_PREP,
 	CPUHP_POWER_NUMA_PREPARE,
 	CPUHP_HRTIMERS_PREPARE,
diff --git a/kernel/padata.c b/kernel/padata.c
index 9e3c4df75907..a2fa6223e1a0 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -512,7 +512,7 @@ static int padata_replace_one(struct padata_shell *ps)
 	return 0;
 }
 
-static int padata_replace(struct padata_instance *pinst, int cpu)
+static int padata_replace(struct padata_instance *pinst)
 {
 	int notification_mask = 0;
 	struct padata_shell *ps;
@@ -523,16 +523,12 @@ static int padata_replace(struct padata_instance *pinst, int cpu)
 	cpumask_copy(pinst->omask, pinst->rcpumask.pcpu);
 	cpumask_and(pinst->rcpumask.pcpu, pinst->cpumask.pcpu,
 		    cpu_online_mask);
-	if (cpu >= 0)
-		cpumask_clear_cpu(cpu, pinst->rcpumask.pcpu);
 	if (!cpumask_equal(pinst->omask, pinst->rcpumask.pcpu))
 		notification_mask |= PADATA_CPU_PARALLEL;
 
 	cpumask_copy(pinst->omask, pinst->rcpumask.cbcpu);
 	cpumask_and(pinst->rcpumask.cbcpu, pinst->cpumask.cbcpu,
 		    cpu_online_mask);
-	if (cpu >= 0)
-		cpumask_clear_cpu(cpu, pinst->rcpumask.cbcpu);
 	if (!cpumask_equal(pinst->omask, pinst->rcpumask.cbcpu))
 		notification_mask |= PADATA_CPU_SERIAL;
 
@@ -624,7 +620,7 @@ static int __padata_set_cpumasks(struct padata_instance *pinst,
 	cpumask_copy(pinst->cpumask.pcpu, pcpumask);
 	cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
 
-	err = padata_setup_cpumasks(pinst) ?: padata_replace(pinst, -1);
+	err = padata_setup_cpumasks(pinst) ?: padata_replace(pinst);
 
 	if (valid)
 		__padata_start(pinst);
@@ -715,7 +711,7 @@ static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
 	int err = 0;
 
 	if (cpumask_test_cpu(cpu, cpu_online_mask)) {
-		err = padata_replace(pinst, -1);
+		err = padata_replace(pinst);
 
 		if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) &&
 		    padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
@@ -729,12 +725,12 @@ static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
 {
 	int err = 0;
 
-	if (cpumask_test_cpu(cpu, cpu_online_mask)) {
+	if (!cpumask_test_cpu(cpu, cpu_online_mask)) {
 		if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) ||
 		    !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
 			__padata_stop(pinst);
 
-		err = padata_replace(pinst, cpu);
+		err = padata_replace(pinst);
 	}
 
 	return err;
@@ -761,7 +757,7 @@ static int padata_cpu_online(unsigned int cpu, struct hlist_node *node)
 	return ret;
 }
 
-static int padata_cpu_prep_down(unsigned int cpu, struct hlist_node *node)
+static int padata_cpu_dead(unsigned int cpu, struct hlist_node *node)
 {
 	struct padata_instance *pinst;
 	int ret;
@@ -782,6 +778,7 @@ static enum cpuhp_state hp_online;
 static void __padata_free(struct padata_instance *pinst)
 {
 #ifdef CONFIG_HOTPLUG_CPU
+	cpuhp_state_remove_instance_nocalls(CPUHP_PADATA_DEAD, &pinst->node);
 	cpuhp_state_remove_instance_nocalls(hp_online, &pinst->node);
 #endif
 
@@ -989,6 +986,8 @@ static struct padata_instance *padata_alloc(const char *name,
 
 #ifdef CONFIG_HOTPLUG_CPU
 	cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, &pinst->node);
+	cpuhp_state_add_instance_nocalls_cpuslocked(CPUHP_PADATA_DEAD,
+						    &pinst->node);
 #endif
 
 	put_online_cpus();
@@ -1101,17 +1100,24 @@ static __init int padata_driver_init(void)
 	int ret;
 
 	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online",
-				      padata_cpu_online,
-				      padata_cpu_prep_down);
+				      padata_cpu_online, NULL);
 	if (ret < 0)
 		return ret;
 	hp_online = ret;
+
+	ret = cpuhp_setup_state_multi(CPUHP_PADATA_DEAD, "padata:dead",
+				      NULL, padata_cpu_dead);
+	if (ret < 0) {
+		cpuhp_remove_multi_state(hp_online);
+		return ret;
+	}
 	return 0;
 }
 module_init(padata_driver_init);
 
 static __exit void padata_driver_exit(void)
 {
+	cpuhp_remove_multi_state(CPUHP_PADATA_DEAD);
 	cpuhp_remove_multi_state(hp_online);
 }
 module_exit(padata_driver_exit);
-- 
2.24.0

[PATCH v2 2/5] padata: always acquire cpu_hotplug_lock before pinst->lock

[Daniel Jordan]

lockdep complains when padata's paths to update cpumasks via CPU hotplug
and sysfs are both taken:

  # echo 0 > /sys/devices/system/cpu/cpu1/online
  # echo ff > /sys/kernel/pcrypt/pencrypt/parallel_cpumask

  ======================================================
  WARNING: possible circular locking dependency detected
  5.4.0-rc8-padata-cpuhp-v3+ #1 Not tainted
  ------------------------------------------------------
  bash/205 is trying to acquire lock:
  ffffffff8286bcd0 (cpu_hotplug_lock.rw_sem){++++}, at: padata_set_cpumask+0x2b/0x120

  but task is already holding lock:
  ffff8880001abfa0 (&pinst->lock){+.+.}, at: padata_set_cpumask+0x26/0x120

  which lock already depends on the new lock.

padata doesn't take cpu_hotplug_lock and pinst->lock in a consistent
order.  Which should be first?  CPU hotplug calls into padata with
cpu_hotplug_lock already held, so it should have priority.

Fixes: 6751fb3c0e0c ("padata: Use get_online_cpus/put_online_cpus")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 kernel/padata.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/padata.c b/kernel/padata.c
index a2fa6223e1a0..2f8db63aefc4 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -643,8 +643,8 @@ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 	struct cpumask *serial_mask, *parallel_mask;
 	int err = -EINVAL;
 
-	mutex_lock(&pinst->lock);
 	get_online_cpus();
+	mutex_lock(&pinst->lock);
 
 	switch (cpumask_type) {
 	case PADATA_CPU_PARALLEL:
@@ -662,8 +662,8 @@ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 	err =  __padata_set_cpumasks(pinst, parallel_mask, serial_mask);
 
 out:
-	put_online_cpus();
 	mutex_unlock(&pinst->lock);
+	put_online_cpus();
 
 	return err;
 }
-- 
2.24.0

[PATCH v2 3/5] padata: remove cpumask change notifier

[Daniel Jordan]

Since commit 63d3578892dc ("crypto: pcrypt - remove padata cpumask
notifier") this feature is unused, so get rid of it.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 Documentation/padata.txt | 24 -------------------
 crypto/pcrypt.c          |  1 -
 include/linux/padata.h   | 11 ---------
 kernel/padata.c          | 52 +---------------------------------------
 4 files changed, 1 insertion(+), 87 deletions(-)

diff --git a/Documentation/padata.txt b/Documentation/padata.txt
index b37ba1eaace3..b45df9c6547b 100644
--- a/Documentation/padata.txt
+++ b/Documentation/padata.txt
@@ -75,30 +75,6 @@ To simply add or remove one CPU from a certain cpumask the functions
 padata_add_cpu/padata_remove_cpu are used. cpu specifies the CPU to add or
 remove and mask is one of PADATA_CPU_SERIAL, PADATA_CPU_PARALLEL.
 
-If a user is interested in padata cpumask changes, he can register to
-the padata cpumask change notifier::
-
-    int padata_register_cpumask_notifier(struct padata_instance *pinst,
-					 struct notifier_block *nblock);
-
-To unregister from that notifier::
-
-    int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
-					   struct notifier_block *nblock);
-
-The padata cpumask change notifier notifies about changes of the usable
-cpumasks, i.e. the subset of active CPUs in the user supplied cpumask.
-
-Padata calls the notifier chain with::
-
-    blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
-				 notification_mask,
-				 &pd_new->cpumask);
-
-Here cpumask_change_notifier is registered notifier, notification_mask
-is one of PADATA_CPU_SERIAL, PADATA_CPU_PARALLEL and cpumask is a pointer
-to a struct padata_cpumask that contains the new cpumask information.
-
 Actually submitting work to the padata instance requires the creation of a
 padata_priv structure::
 
diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
index a4f3b3f342c8..d6696e217128 100644
--- a/crypto/pcrypt.c
+++ b/crypto/pcrypt.c
@@ -13,7 +13,6 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/slab.h>
-#include <linux/notifier.h>
 #include <linux/kobject.h>
 #include <linux/cpu.h>
 #include <crypto/pcrypt.h>
diff --git a/include/linux/padata.h b/include/linux/padata.h
index cccab7a59787..178d5cc6b494 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -13,7 +13,6 @@
 #include <linux/workqueue.h>
 #include <linux/spinlock.h>
 #include <linux/list.h>
-#include <linux/notifier.h>
 #include <linux/kobject.h>
 
 #define PADATA_CPU_SERIAL   0x01
@@ -151,10 +150,6 @@ struct padata_shell {
  * @pslist: List of padata_shell objects attached to this instance.
  * @cpumask: User supplied cpumasks for parallel and serial works.
  * @rcpumask: Actual cpumasks based on user cpumask and cpu_online_mask.
- * @omask: Temporary storage used to compute the notification mask.
- * @cpumask_change_notifier: Notifiers chain for user-defined notify
- *            callbacks that will be called when either @pcpu or @cbcpu
- *            or both cpumasks change.
  * @kobj: padata instance kernel object.
  * @lock: padata instance lock.
  * @flags: padata flags.
@@ -166,8 +161,6 @@ struct padata_instance {
 	struct list_head		pslist;
 	struct padata_cpumask		cpumask;
 	struct padata_cpumask		rcpumask;
-	cpumask_var_t			omask;
-	struct blocking_notifier_head	 cpumask_change_notifier;
 	struct kobject                   kobj;
 	struct mutex			 lock;
 	u8				 flags;
@@ -187,8 +180,4 @@ extern int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 			      cpumask_var_t cpumask);
 extern int padata_start(struct padata_instance *pinst);
 extern void padata_stop(struct padata_instance *pinst);
-extern int padata_register_cpumask_notifier(struct padata_instance *pinst,
-					    struct notifier_block *nblock);
-extern int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
-					      struct notifier_block *nblock);
 #endif
diff --git a/kernel/padata.c b/kernel/padata.c
index 2f8db63aefc4..c7edc6bf2bdc 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -514,23 +514,16 @@ static int padata_replace_one(struct padata_shell *ps)
 
 static int padata_replace(struct padata_instance *pinst)
 {
-	int notification_mask = 0;
 	struct padata_shell *ps;
 	int err;
 
 	pinst->flags |= PADATA_RESET;
 
-	cpumask_copy(pinst->omask, pinst->rcpumask.pcpu);
 	cpumask_and(pinst->rcpumask.pcpu, pinst->cpumask.pcpu,
 		    cpu_online_mask);
-	if (!cpumask_equal(pinst->omask, pinst->rcpumask.pcpu))
-		notification_mask |= PADATA_CPU_PARALLEL;
 
-	cpumask_copy(pinst->omask, pinst->rcpumask.cbcpu);
 	cpumask_and(pinst->rcpumask.cbcpu, pinst->cpumask.cbcpu,
 		    cpu_online_mask);
-	if (!cpumask_equal(pinst->omask, pinst->rcpumask.cbcpu))
-		notification_mask |= PADATA_CPU_SERIAL;
 
 	list_for_each_entry(ps, &pinst->pslist, list) {
 		err = padata_replace_one(ps);
@@ -544,48 +537,11 @@ static int padata_replace(struct padata_instance *pinst)
 		if (atomic_dec_and_test(&ps->opd->refcnt))
 			padata_free_pd(ps->opd);
 
-	if (notification_mask)
-		blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
-					     notification_mask,
-					     &pinst->cpumask);
-
 	pinst->flags &= ~PADATA_RESET;
 
 	return err;
 }
 
-/**
- * padata_register_cpumask_notifier - Registers a notifier that will be called
- *                             if either pcpu or cbcpu or both cpumasks change.
- *
- * @pinst: A poineter to padata instance
- * @nblock: A pointer to notifier block.
- */
-int padata_register_cpumask_notifier(struct padata_instance *pinst,
-				     struct notifier_block *nblock)
-{
-	return blocking_notifier_chain_register(&pinst->cpumask_change_notifier,
-						nblock);
-}
-EXPORT_SYMBOL(padata_register_cpumask_notifier);
-
-/**
- * padata_unregister_cpumask_notifier - Unregisters cpumask notifier
- *        registered earlier  using padata_register_cpumask_notifier
- *
- * @pinst: A pointer to data instance.
- * @nlock: A pointer to notifier block.
- */
-int padata_unregister_cpumask_notifier(struct padata_instance *pinst,
-				       struct notifier_block *nblock)
-{
-	return blocking_notifier_chain_unregister(
-		&pinst->cpumask_change_notifier,
-		nblock);
-}
-EXPORT_SYMBOL(padata_unregister_cpumask_notifier);
-
-
 /* If cpumask contains no active cpu, we mark the instance as invalid. */
 static bool padata_validate_cpumask(struct padata_instance *pinst,
 				    const struct cpumask *cpumask)
@@ -785,7 +741,6 @@ static void __padata_free(struct padata_instance *pinst)
 	WARN_ON(!list_empty(&pinst->pslist));
 
 	padata_stop(pinst);
-	free_cpumask_var(pinst->omask);
 	free_cpumask_var(pinst->rcpumask.cbcpu);
 	free_cpumask_var(pinst->rcpumask.pcpu);
 	free_cpumask_var(pinst->cpumask.pcpu);
@@ -965,8 +920,6 @@ static struct padata_instance *padata_alloc(const char *name,
 		goto err_free_masks;
 	if (!alloc_cpumask_var(&pinst->rcpumask.cbcpu, GFP_KERNEL))
 		goto err_free_rcpumask_pcpu;
-	if (!alloc_cpumask_var(&pinst->omask, GFP_KERNEL))
-		goto err_free_rcpumask_cbcpu;
 
 	INIT_LIST_HEAD(&pinst->pslist);
 
@@ -976,11 +929,10 @@ static struct padata_instance *padata_alloc(const char *name,
 	cpumask_and(pinst->rcpumask.cbcpu, cbcpumask, cpu_online_mask);
 
 	if (padata_setup_cpumasks(pinst))
-		goto err_free_omask;
+		goto err_free_rcpumask_cbcpu;
 
 	pinst->flags = 0;
 
-	BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
 	kobject_init(&pinst->kobj, &padata_attr_type);
 	mutex_init(&pinst->lock);
 
@@ -994,8 +946,6 @@ static struct padata_instance *padata_alloc(const char *name,
 
 	return pinst;
 
-err_free_omask:
-	free_cpumask_var(pinst->omask);
 err_free_rcpumask_cbcpu:
 	free_cpumask_var(pinst->rcpumask.cbcpu);
 err_free_rcpumask_pcpu:
-- 
2.24.0

[PATCH v2 4/5] padata: remove reorder_objects

[Daniel Jordan]

reorder_objects is unused since the rework of padata's flushing, so
remove it.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 include/linux/padata.h | 2 --
 kernel/padata.c        | 3 ---
 2 files changed, 5 deletions(-)

diff --git a/include/linux/padata.h b/include/linux/padata.h
index 178d5cc6b494..faa2e36832f8 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -101,7 +101,6 @@ struct padata_cpumask {
  * @sh: padata_shell object.
  * @pqueue: percpu padata queues used for parallelization.
  * @squeue: percpu padata queues used for serialuzation.
- * @reorder_objects: Number of objects waiting in the reorder queues.
  * @refcnt: Number of objects holding a reference on this parallel_data.
  * @max_seq_nr:  Maximal used sequence number.
  * @processed: Number of already processed objects.
@@ -114,7 +113,6 @@ struct parallel_data {
 	struct padata_shell		*ps;
 	struct padata_parallel_queue	__percpu *pqueue;
 	struct padata_serial_queue	__percpu *squeue;
-	atomic_t			reorder_objects;
 	atomic_t			refcnt;
 	atomic_t			seq_nr;
 	unsigned int			processed;
diff --git a/kernel/padata.c b/kernel/padata.c
index c7edc6bf2bdc..2aaf677db85c 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -202,7 +202,6 @@ static struct padata_priv *padata_find_next(struct parallel_data *pd,
 
 	if (remove_object) {
 		list_del_init(&padata->list);
-		atomic_dec(&pd->reorder_objects);
 		++pd->processed;
 		pd->cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu, -1, false);
 	}
@@ -336,7 +335,6 @@ void padata_do_serial(struct padata_priv *padata)
 		if (cur->seq_nr < padata->seq_nr)
 			break;
 	list_add(&padata->list, &cur->list);
-	atomic_inc(&pd->reorder_objects);
 	spin_unlock(&pqueue->reorder.lock);
 
 	/*
@@ -455,7 +453,6 @@ static struct parallel_data *padata_alloc_pd(struct padata_shell *ps)
 	padata_init_pqueues(pd);
 	padata_init_squeues(pd);
 	atomic_set(&pd->seq_nr, -1);
-	atomic_set(&pd->reorder_objects, 0);
 	atomic_set(&pd->refcnt, 1);
 	spin_lock_init(&pd->lock);
 	pd->cpu = cpumask_first(pd->cpumask.pcpu);
-- 
2.24.0

[PATCH v2 5/5] padata: update documentation

[Daniel Jordan]

Remove references to unused functions, standardize language, update to
reflect new functionality, migrate to rst format, and fix all kernel-doc
warnings.

Fixes: 815613da6a67 ("kernel/padata.c: removed unused code")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 Documentation/core-api/index.rst  |   1 +
 Documentation/core-api/padata.rst | 169 ++++++++++++++++++++++++++++++
 Documentation/padata.txt          | 139 ------------------------
 include/linux/padata.h            |  15 ++-
 kernel/padata.c                   |  35 ++++---
 5 files changed, 198 insertions(+), 161 deletions(-)
 create mode 100644 Documentation/core-api/padata.rst
 delete mode 100644 Documentation/padata.txt

diff --git a/Documentation/core-api/index.rst b/Documentation/core-api/index.rst
index ab0eae1c153a..ab0b9ec85506 100644
--- a/Documentation/core-api/index.rst
+++ b/Documentation/core-api/index.rst
@@ -39,6 +39,7 @@ Core utilities
    ../RCU/index
    gcc-plugins
    symbol-namespaces
+   padata
 
 
 Interfaces for kernel debugging
diff --git a/Documentation/core-api/padata.rst b/Documentation/core-api/padata.rst
new file mode 100644
index 000000000000..9a24c111781d
--- /dev/null
+++ b/Documentation/core-api/padata.rst
@@ -0,0 +1,169 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=======================================
+The padata parallel execution mechanism
+=======================================
+
+:Date: December 2019
+
+Padata is a mechanism by which the kernel can farm jobs out to be done in
+parallel on multiple CPUs while retaining their ordering.  It was developed for
+use with the IPsec code, which needs to be able to perform encryption and
+decryption on large numbers of packets without reordering those packets.  The
+crypto developers made a point of writing padata in a sufficiently general
+fashion that it could be put to other uses as well.
+
+Usage
+=====
+
+Initializing
+------------
+
+The first step in using padata is to set up a padata_instance structure for
+overall control of how jobs are to be run::
+
+    #include <linux/padata.h>
+
+    struct padata_instance *padata_alloc_possible(const char *name);
+
+'name' simply identifies the instance.
+
+There are functions for enabling and disabling the instance::
+
+    int padata_start(struct padata_instance *pinst);
+    void padata_stop(struct padata_instance *pinst);
+
+These functions are setting or clearing the "PADATA_INIT" flag; if that flag is
+not set, other functions will refuse to work.  padata_start() returns zero on
+success (flag set) or -EINVAL if the padata cpumask contains no active CPU
+(flag not set).  padata_stop() clears the flag and blocks until the padata
+instance is unused.
+
+Finally, complete padata initialization by allocating a padata_shell::
+
+   struct padata_shell *padata_alloc_shell(struct padata_instance *pinst);
+
+A padata_shell is used to submit a job to padata and allows a series of such
+jobs to be serialized independently.  A padata_instance may have one or more
+padata_shells associated with it, each allowing a separate series of jobs.
+
+Modifying cpumasks
+------------------
+
+The CPUs used to run jobs can be changed in two ways, programatically with
+padata_set_cpumask() or via sysfs.  The former is defined::
+
+    int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
+			   cpumask_var_t cpumask);
+
+Here cpumask_type is one of PADATA_CPU_PARALLEL or PADATA_CPU_SERIAL, where a
+parallel cpumask describes which processors will be used to execute jobs
+submitted to this instance in parallel and a serial cpumask defines which
+processors are allowed to be used as the serialization callback processor.
+cpumask specifies the new cpumask to use.
+
+There may be sysfs files for an instance's cpumasks.  For example, pcrypt's
+live in /sys/kernel/pcrypt/<instance-name>.  Within an instance's directory
+there are two files, parallel_cpumask and serial_cpumask, and either cpumask
+may be changed by echoing a bitmask into the file, for example::
+
+    echo f > /sys/kernel/pcrypt/pencrypt/parallel_cpumask
+
+Reading one of these files shows the user-supplied cpumask, which may be
+different from the 'usable' cpumask.
+
+Padata maintains two pairs of cpumasks internally, the user-supplied cpumasks
+and the 'usable' cpumasks.  (Each pair consists of a parallel and a serial
+cpumask.)  The user-supplied cpumasks default to all possible CPUs on instance
+allocation and may be changed as above.  The usable cpumasks are always a
+subset of the user-supplied cpumasks and contain only the online CPUs in the
+user-supplied masks; these are the cpumasks padata actually uses.  So it is
+legal to supply a cpumask to padata that contains offline CPUs.  Once an
+offline CPU in the user-supplied cpumask comes online, padata is going to use
+it.
+
+Changing the CPU masks are expensive operations, so it should not be done with
+great frequency.
+
+Running A Job
+-------------
+
+Actually submitting work to the padata instance requires the creation of a
+padata_priv structure, which represents one job::
+
+    struct padata_priv {
+        /* Other stuff here... */
+	void                    (*parallel)(struct padata_priv *padata);
+	void                    (*serial)(struct padata_priv *padata);
+    };
+
+This structure will almost certainly be embedded within some larger
+structure specific to the work to be done.  Most of its fields are private to
+padata, but the structure should be zeroed at initialisation time, and the
+parallel() and serial() functions should be provided.  Those functions will
+be called in the process of getting the work done as we will see
+momentarily.
+
+The submission of the job is done with::
+
+    int padata_do_parallel(struct padata_shell *ps,
+		           struct padata_priv *padata, int *cb_cpu);
+
+The ps and padata structures must be set up as described above; cb_cpu
+points to the preferred CPU to be used for the final callback when the job is
+done; it must be in the current instance's CPU mask (if not the cb_cpu pointer
+is updated to point to the CPU actually chosen).  The return value from
+padata_do_parallel() is zero on success, indicating that the job is in
+progress. -EBUSY means that somebody, somewhere else is messing with the
+instance's CPU mask, while -EINVAL is a complaint about cb_cpu not being in the
+serial cpumask, no online CPUs in the parallel or serial cpumasks, or a stopped
+instance.
+
+Each job submitted to padata_do_parallel() will, in turn, be passed to
+exactly one call to the above-mentioned parallel() function, on one CPU, so
+true parallelism is achieved by submitting multiple jobs.  parallel() runs with
+software interrupts disabled and thus cannot sleep.  The parallel()
+function gets the padata_priv structure pointer as its lone parameter;
+information about the actual work to be done is probably obtained by using
+container_of() to find the enclosing structure.
+
+Note that parallel() has no return value; the padata subsystem assumes that
+parallel() will take responsibility for the job from this point.  The job
+need not be completed during this call, but, if parallel() leaves work
+outstanding, it should be prepared to be called again with a new job before
+the previous one completes.
+
+Serializing Jobs
+----------------
+
+When a job does complete, parallel() (or whatever function actually finishes
+the work) should inform padata of the fact with a call to::
+
+    void padata_do_serial(struct padata_priv *padata);
+
+At some point in the future, padata_do_serial() will trigger a call to the
+serial() function in the padata_priv structure.  That call will happen on
+the CPU requested in the initial call to padata_do_parallel(); it, too, is
+run with local software interrupts disabled.
+Note that this call may be deferred for a while since the padata code takes
+pains to ensure that jobs are completed in the order in which they were
+submitted.
+
+Destroying
+----------
+
+Cleaning up a padata instance predictably involves calling the three free
+functions that correspond to the allocation in reverse::
+
+    void padata_free_shell(struct padata_shell *ps);
+    void padata_stop(struct padata_instance *pinst);
+    void padata_free(struct padata_instance *pinst);
+
+It is the user's responsibility to ensure all outstanding jobs are complete
+before any of the above are called.
+
+Interface
+=========
+
+.. kernel-doc:: include/linux/padata.h
+.. kernel-doc:: kernel/padata.c
diff --git a/Documentation/padata.txt b/Documentation/padata.txt
deleted file mode 100644
index b45df9c6547b..000000000000
--- a/Documentation/padata.txt
+++ /dev/null
@@ -1,139 +0,0 @@
-=======================================
-The padata parallel execution mechanism
-=======================================
-
-:Last updated: for 2.6.36
-
-Padata is a mechanism by which the kernel can farm work out to be done in
-parallel on multiple CPUs while retaining the ordering of tasks.  It was
-developed for use with the IPsec code, which needs to be able to perform
-encryption and decryption on large numbers of packets without reordering
-those packets.  The crypto developers made a point of writing padata in a
-sufficiently general fashion that it could be put to other uses as well.
-
-The first step in using padata is to set up a padata_instance structure for
-overall control of how tasks are to be run::
-
-    #include <linux/padata.h>
-
-    struct padata_instance *padata_alloc(const char *name,
-					 const struct cpumask *pcpumask,
-					 const struct cpumask *cbcpumask);
-
-'name' simply identifies the instance.
-
-The pcpumask describes which processors will be used to execute work
-submitted to this instance in parallel. The cbcpumask defines which
-processors are allowed to be used as the serialization callback processor.
-The workqueue wq is where the work will actually be done; it should be
-a multithreaded queue, naturally.
-
-To allocate a padata instance with the cpu_possible_mask for both
-cpumasks this helper function can be used::
-
-    struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq);
-
-Note: Padata maintains two kinds of cpumasks internally. The user supplied
-cpumasks, submitted by padata_alloc/padata_alloc_possible and the 'usable'
-cpumasks. The usable cpumasks are always a subset of active CPUs in the
-user supplied cpumasks; these are the cpumasks padata actually uses. So
-it is legal to supply a cpumask to padata that contains offline CPUs.
-Once an offline CPU in the user supplied cpumask comes online, padata
-is going to use it.
-
-There are functions for enabling and disabling the instance::
-
-    int padata_start(struct padata_instance *pinst);
-    void padata_stop(struct padata_instance *pinst);
-
-These functions are setting or clearing the "PADATA_INIT" flag;
-if that flag is not set, other functions will refuse to work.
-padata_start returns zero on success (flag set) or -EINVAL if the
-padata cpumask contains no active CPU (flag not set).
-padata_stop clears the flag and blocks until the padata instance
-is unused.
-
-The list of CPUs to be used can be adjusted with these functions::
-
-    int padata_set_cpumasks(struct padata_instance *pinst,
-			    cpumask_var_t pcpumask,
-			    cpumask_var_t cbcpumask);
-    int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
-			   cpumask_var_t cpumask);
-    int padata_add_cpu(struct padata_instance *pinst, int cpu, int mask);
-    int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask);
-
-Changing the CPU masks are expensive operations, though, so it should not be
-done with great frequency.
-
-It's possible to change both cpumasks of a padata instance with
-padata_set_cpumasks by specifying the cpumasks for parallel execution (pcpumask)
-and for the serial callback function (cbcpumask). padata_set_cpumask is used to
-change just one of the cpumasks. Here cpumask_type is one of PADATA_CPU_SERIAL,
-PADATA_CPU_PARALLEL and cpumask specifies the new cpumask to use.
-To simply add or remove one CPU from a certain cpumask the functions
-padata_add_cpu/padata_remove_cpu are used. cpu specifies the CPU to add or
-remove and mask is one of PADATA_CPU_SERIAL, PADATA_CPU_PARALLEL.
-
-Actually submitting work to the padata instance requires the creation of a
-padata_priv structure::
-
-    struct padata_priv {
-        /* Other stuff here... */
-	void                    (*parallel)(struct padata_priv *padata);
-	void                    (*serial)(struct padata_priv *padata);
-    };
-
-This structure will almost certainly be embedded within some larger
-structure specific to the work to be done.  Most of its fields are private to
-padata, but the structure should be zeroed at initialisation time, and the
-parallel() and serial() functions should be provided.  Those functions will
-be called in the process of getting the work done as we will see
-momentarily.
-
-The submission of work is done with::
-
-    int padata_do_parallel(struct padata_instance *pinst,
-		           struct padata_priv *padata, int cb_cpu);
-
-The pinst and padata structures must be set up as described above; cb_cpu
-specifies which CPU will be used for the final callback when the work is
-done; it must be in the current instance's CPU mask.  The return value from
-padata_do_parallel() is zero on success, indicating that the work is in
-progress. -EBUSY means that somebody, somewhere else is messing with the
-instance's CPU mask, while -EINVAL is a complaint about cb_cpu not being
-in that CPU mask or about a not running instance.
-
-Each task submitted to padata_do_parallel() will, in turn, be passed to
-exactly one call to the above-mentioned parallel() function, on one CPU, so
-true parallelism is achieved by submitting multiple tasks.  parallel() runs with
-software interrupts disabled and thus cannot sleep.  The parallel()
-function gets the padata_priv structure pointer as its lone parameter;
-information about the actual work to be done is probably obtained by using
-container_of() to find the enclosing structure.
-
-Note that parallel() has no return value; the padata subsystem assumes that
-parallel() will take responsibility for the task from this point.  The work
-need not be completed during this call, but, if parallel() leaves work
-outstanding, it should be prepared to be called again with a new job before
-the previous one completes.  When a task does complete, parallel() (or
-whatever function actually finishes the job) should inform padata of the
-fact with a call to::
-
-    void padata_do_serial(struct padata_priv *padata);
-
-At some point in the future, padata_do_serial() will trigger a call to the
-serial() function in the padata_priv structure.  That call will happen on
-the CPU requested in the initial call to padata_do_parallel(); it, too, is
-run with local software interrupts disabled.
-Note that this call may be deferred for a while since the padata code takes
-pains to ensure that tasks are completed in the order in which they were
-submitted.
-
-The one remaining function in the padata API should be called to clean up
-when a padata instance is no longer needed::
-
-    void padata_free(struct padata_instance *pinst);
-
-This function will busy-wait while any remaining tasks are completed, so it
-might be best not to call it while there is work outstanding.
diff --git a/include/linux/padata.h b/include/linux/padata.h
index faa2e36832f8..a0d8b41850b2 100644
--- a/include/linux/padata.h
+++ b/include/linux/padata.h
@@ -19,7 +19,7 @@
 #define PADATA_CPU_PARALLEL 0x02
 
 /**
- * struct padata_priv -  Embedded to the users data structure.
+ * struct padata_priv - Represents one job
  *
  * @list: List entry, to attach to the padata lists.
  * @pd: Pointer to the internal control structure.
@@ -42,7 +42,7 @@ struct padata_priv {
 };
 
 /**
- * struct padata_list
+ * struct padata_list - one per work type per CPU
  *
  * @list: List head.
  * @lock: List lock.
@@ -70,9 +70,6 @@ struct padata_serial_queue {
  *
  * @parallel: List to wait for parallelization.
  * @reorder: List to wait for reordering after parallel processing.
- * @serial: List to wait for serialization after reordering.
- * @pwork: work struct for parallelization.
- * @swork: work struct for serialization.
  * @work: work struct for parallelization.
  * @num_obj: Number of objects that are processed by this cpu.
  */
@@ -98,11 +95,11 @@ struct padata_cpumask {
  * struct parallel_data - Internal control structure, covers everything
  * that depends on the cpumask in use.
  *
- * @sh: padata_shell object.
+ * @ps: padata_shell object.
  * @pqueue: percpu padata queues used for parallelization.
  * @squeue: percpu padata queues used for serialuzation.
  * @refcnt: Number of objects holding a reference on this parallel_data.
- * @max_seq_nr:  Maximal used sequence number.
+ * @seq_nr: Sequence number of the parallelized data object.
  * @processed: Number of already processed objects.
  * @cpu: Next CPU to be processed.
  * @cpumask: The cpumasks in use for parallel and serial workers.
@@ -119,7 +116,7 @@ struct parallel_data {
 	int				cpu;
 	struct padata_cpumask		cpumask;
 	struct work_struct		reorder_work;
-	spinlock_t                      lock ____cacheline_aligned;
+	spinlock_t                      ____cacheline_aligned lock;
 };
 
 /**
@@ -142,7 +139,7 @@ struct padata_shell {
 /**
  * struct padata_instance - The overall control structure.
  *
- * @cpu_notifier: cpu hotplug notifier.
+ * @node: Used by CPU hotplug.
  * @parallel_wq: The workqueue used for parallel work.
  * @serial_wq: The workqueue used for serial work.
  * @pslist: List of padata_shell objects attached to this instance.
diff --git a/kernel/padata.c b/kernel/padata.c
index 2aaf677db85c..376e5d8d1c5c 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -2,7 +2,7 @@
 /*
  * padata.c - generic interface to process data streams in parallel
  *
- * See Documentation/padata.txt for an api documentation.
+ * See Documentation/core-api/padata.rst for more information.
  *
  * Copyright (C) 2008, 2009 secunet Security Networks AG
  * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
@@ -99,6 +99,8 @@ static void padata_parallel_worker(struct work_struct *parallel_work)
  * The parallelization callback function will run with BHs off.
  * Note: Every object which is parallelized by padata_do_parallel
  * must be seen by padata_do_serial.
+ *
+ * Return: 0 on success or else negative error code.
  */
 int padata_do_parallel(struct padata_shell *ps,
 		       struct padata_priv *padata, int *cb_cpu)
@@ -163,14 +165,12 @@ EXPORT_SYMBOL(padata_do_parallel);
 /*
  * padata_find_next - Find the next object that needs serialization.
  *
- * Return values are:
- *
- * A pointer to the control struct of the next object that needs
- * serialization, if present in one of the percpu reorder queues.
- *
- * NULL, if the next object that needs serialization will
- *  be parallel processed by another cpu and is not yet present in
- *  the cpu's reorder queue.
+ * Return:
+ * * A pointer to the control struct of the next object that needs
+ *   serialization, if present in one of the percpu reorder queues.
+ * * NULL, if the next object that needs serialization will
+ *   be parallel processed by another cpu and is not yet present in
+ *   the cpu's reorder queue.
  */
 static struct padata_priv *padata_find_next(struct parallel_data *pd,
 					    bool remove_object)
@@ -582,13 +582,14 @@ static int __padata_set_cpumasks(struct padata_instance *pinst,
 }
 
 /**
- * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value
- *                     equivalent to @cpumask.
- *
+ * padata_set_cpumask - Sets specified by @cpumask_type cpumask to the value
+ *                      equivalent to @cpumask.
  * @pinst: padata instance
  * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding
  *                to parallel and serial cpumasks respectively.
  * @cpumask: the cpumask to use
+ *
+ * Return: 0 on success or negative error code
  */
 int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
 		       cpumask_var_t cpumask)
@@ -626,6 +627,8 @@ EXPORT_SYMBOL(padata_set_cpumask);
  * padata_start - start the parallel processing
  *
  * @pinst: padata instance to start
+ *
+ * Return: 0 on success or negative error code
  */
 int padata_start(struct padata_instance *pinst)
 {
@@ -880,6 +883,8 @@ static struct kobj_type padata_attr_type = {
  * @name: used to identify the instance
  * @pcpumask: cpumask that will be used for padata parallelization
  * @cbcpumask: cpumask that will be used for padata serialization
+ *
+ * Return: new instance on success, NULL on error
  */
 static struct padata_instance *padata_alloc(const char *name,
 					    const struct cpumask *pcpumask,
@@ -967,6 +972,8 @@ static struct padata_instance *padata_alloc(const char *name,
  *                         parallel workers.
  *
  * @name: used to identify the instance
+ *
+ * Return: new instance on success, NULL on error
  */
 struct padata_instance *padata_alloc_possible(const char *name)
 {
@@ -977,7 +984,7 @@ EXPORT_SYMBOL(padata_alloc_possible);
 /**
  * padata_free - free a padata instance
  *
- * @padata_inst: padata instance to free
+ * @pinst: padata instance to free
  */
 void padata_free(struct padata_instance *pinst)
 {
@@ -989,6 +996,8 @@ EXPORT_SYMBOL(padata_free);
  * padata_alloc_shell - Allocate and initialize padata shell.
  *
  * @pinst: Parent padata_instance object.
+ *
+ * Return: new shell on success, NULL on error
  */
 struct padata_shell *padata_alloc_shell(struct padata_instance *pinst)
 {
-- 
2.24.0

Re: [PATCH v2 5/5] padata: update documentation

[Daniel Jordan]

Small fixup for this patch.

Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
---
 MAINTAINERS | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 9d3a5c54a41d..eefd665d41a1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12253,7 +12253,7 @@ L:	linux-crypto@vger.kernel.org
 S:	Maintained
 F:	kernel/padata.c
 F:	include/linux/padata.h
-F:	Documentation/padata.txt
+F:	Documentation/core-api/padata.rst
 
 PAGE POOL
 M:	Jesper Dangaard Brouer <hawk@kernel.org>
-- 
2.24.0

Re: [PATCH v2 0/5] padata lockdep, cpumask, and doc fixes

[Herbert Xu]

On Tue, Dec 03, 2019 at 02:31:09PM -0500, Daniel Jordan wrote:
> This series depends on all of Herbert's recent padata fixes to reduce
> merge conflicts on his end:
> 
>   crypto: pcrypt - Do not clear MAY_SLEEP flag in original request
>   padata: Remove unused padata_remove_cpu
>   [v3] crypto: pcrypt - Avoid deadlock by using per-instance padata queues
>   crypto: pcrypt - Fix user-after-free on module unload
>   padata: Remove broken queue flushing 
> 
> If this should be based on something else, please let me know.
> 
> Thanks,
> Daniel
> 
> v2:
>  - documentation patch RST-ized according to Jon's comments
>  - "validate cpumask" patch added
>  - rebased onto v5.4 and updated since Herbert's fixes have changed
> 
> Daniel Jordan (5):
>   padata: validate cpumask without removed CPU during offline
>   padata: always acquire cpu_hotplug_lock before pinst->lock
>   padata: remove cpumask change notifier
>   padata: remove reorder_objects
>   padata: update documentation
> 
>  Documentation/core-api/index.rst  |   1 +
>  Documentation/core-api/padata.rst | 169 ++++++++++++++++++++++++++++++
>  Documentation/padata.txt          | 163 ----------------------------
>  crypto/pcrypt.c                   |   1 -
>  include/linux/cpuhotplug.h        |   1 +
>  include/linux/padata.h            |  28 ++---
>  kernel/padata.c                   | 124 ++++++++--------------
>  7 files changed, 220 insertions(+), 267 deletions(-)
>  create mode 100644 Documentation/core-api/padata.rst
>  delete mode 100644 Documentation/padata.txt

All applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH v2 5/5] padata: update documentation

[Herbert Xu]

On Tue, Dec 10, 2019 at 11:44:41AM -0500, Daniel Jordan wrote:
> Small fixup for this patch.
> 
> Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
> ---
>  MAINTAINERS | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 9d3a5c54a41d..eefd665d41a1 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -12253,7 +12253,7 @@ L:	linux-crypto@vger.kernel.org
>  S:	Maintained
>  F:	kernel/padata.c
>  F:	include/linux/padata.h
> -F:	Documentation/padata.txt
> +F:	Documentation/core-api/padata.rst
>  
>  PAGE POOL
>  M:	Jesper Dangaard Brouer <hawk@kernel.org>

Please resend this as an incremental patch.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt