Re: [PATCH 45/51] md, raid5: Fix CPU hotplug callback registration
On 02/06, Srivatsa S. Bhat wrote: > > On 02/06/2014 06:41 AM, NeilBrown wrote: > > Shall I wait for a signed-of-by from Oleg, then queue it through my md tree? > > > > Sure, that sounds great, since this patch doesn't have any dependency. > Thanks a lot! > > Oleg, it would be great if you could kindly add your S-O-B to this patch. > Thanks! Thanks Neil and Srivatsa, Sure, feel free to add Signed-off-by: Oleg Nesterov -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 45/51] md, raid5: Fix CPU hotplug callback registration
On 02/06/2014 06:41 AM, NeilBrown wrote: > On Thu, 06 Feb 2014 03:42:45 +0530 "Srivatsa S. Bhat" > wrote: > >> From: Oleg Nesterov >> >> Subsystems that want to register CPU hotplug callbacks, as well as perform >> initialization for the CPUs that are already online, often do it as shown >> below: >> >> get_online_cpus(); >> >> for_each_online_cpu(cpu) >> init_cpu(cpu); >> >> register_cpu_notifier(_cpu_notifier); >> >> put_online_cpus(); >> >> This is wrong, since it is prone to ABBA deadlocks involving the >> cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently >> with CPU hotplug operations). >> >> Interestingly, the raid5 code can actually prevent double initialization and >> hence can use the following simplified form of callback registration: >> >> register_cpu_notifier(_cpu_notifier); >> >> get_online_cpus(); >> >> for_each_online_cpu(cpu) >> init_cpu(cpu); >> >> put_online_cpus(); >> >> A hotplug operation that occurs between registering the notifier and calling >> get_online_cpus(), won't disrupt anything, because the code takes care to >> perform the memory allocations only once. >> >> So reorganize the code in raid5 this way to fix the deadlock with callback >> registration. >> >> Cc: Neil Brown >> Cc: linux-r...@vger.kernel.org >> Cc: sta...@vger.kernel.org >> [Srivatsa: Fixed the unregister_cpu_notifier() deadlock, added the >> free_scratch_buffer() helper to condense code further and wrote the >> changelog.] >> Signed-off-by: Srivatsa S. Bhat >> --- [...] > > > Looks good, thanks. > Shall I wait for a signed-of-by from Oleg, then queue it through my md tree? > Sure, that sounds great, since this patch doesn't have any dependency. Thanks a lot! Oleg, it would be great if you could kindly add your S-O-B to this patch. Thanks! Regards, Srivatsa S. Bhat -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 45/51] md, raid5: Fix CPU hotplug callback registration
On 02/06/2014 06:41 AM, NeilBrown wrote: On Thu, 06 Feb 2014 03:42:45 +0530 Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com wrote: From: Oleg Nesterov o...@redhat.com Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Interestingly, the raid5 code can actually prevent double initialization and hence can use the following simplified form of callback registration: register_cpu_notifier(foobar_cpu_notifier); get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); put_online_cpus(); A hotplug operation that occurs between registering the notifier and calling get_online_cpus(), won't disrupt anything, because the code takes care to perform the memory allocations only once. So reorganize the code in raid5 this way to fix the deadlock with callback registration. Cc: Neil Brown ne...@suse.de Cc: linux-r...@vger.kernel.org Cc: sta...@vger.kernel.org [Srivatsa: Fixed the unregister_cpu_notifier() deadlock, added the free_scratch_buffer() helper to condense code further and wrote the changelog.] Signed-off-by: Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com --- [...] Looks good, thanks. Shall I wait for a signed-of-by from Oleg, then queue it through my md tree? Sure, that sounds great, since this patch doesn't have any dependency. Thanks a lot! Oleg, it would be great if you could kindly add your S-O-B to this patch. Thanks! Regards, Srivatsa S. Bhat -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 45/51] md, raid5: Fix CPU hotplug callback registration
On 02/06, Srivatsa S. Bhat wrote: On 02/06/2014 06:41 AM, NeilBrown wrote: Shall I wait for a signed-of-by from Oleg, then queue it through my md tree? Sure, that sounds great, since this patch doesn't have any dependency. Thanks a lot! Oleg, it would be great if you could kindly add your S-O-B to this patch. Thanks! Thanks Neil and Srivatsa, Sure, feel free to add Signed-off-by: Oleg Nesterov o...@redhat.com -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 45/51] md, raid5: Fix CPU hotplug callback registration
On Thu, 06 Feb 2014 03:42:45 +0530 "Srivatsa S. Bhat"
wrote:
> From: Oleg Nesterov
>
> Subsystems that want to register CPU hotplug callbacks, as well as perform
> initialization for the CPUs that are already online, often do it as shown
> below:
>
> get_online_cpus();
>
> for_each_online_cpu(cpu)
> init_cpu(cpu);
>
> register_cpu_notifier(_cpu_notifier);
>
> put_online_cpus();
>
> This is wrong, since it is prone to ABBA deadlocks involving the
> cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
> with CPU hotplug operations).
>
> Interestingly, the raid5 code can actually prevent double initialization and
> hence can use the following simplified form of callback registration:
>
> register_cpu_notifier(_cpu_notifier);
>
> get_online_cpus();
>
> for_each_online_cpu(cpu)
> init_cpu(cpu);
>
> put_online_cpus();
>
> A hotplug operation that occurs between registering the notifier and calling
> get_online_cpus(), won't disrupt anything, because the code takes care to
> perform the memory allocations only once.
>
> So reorganize the code in raid5 this way to fix the deadlock with callback
> registration.
>
> Cc: Neil Brown
> Cc: linux-r...@vger.kernel.org
> Cc: sta...@vger.kernel.org
> [Srivatsa: Fixed the unregister_cpu_notifier() deadlock, added the
> free_scratch_buffer() helper to condense code further and wrote the
> changelog.]
> Signed-off-by: Srivatsa S. Bhat
> ---
>
> drivers/md/raid5.c | 90
> +---
> 1 file changed, 44 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index f1feade..16f5c21 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -5514,23 +5514,43 @@ raid5_size(struct mddev *mddev, sector_t sectors, int
> raid_disks)
> return sectors * (raid_disks - conf->max_degraded);
> }
>
> +static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu
> *percpu)
> +{
> + safe_put_page(percpu->spare_page);
> + kfree(percpu->scribble);
> + percpu->spare_page = NULL;
> + percpu->scribble = NULL;
> +}
> +
> +static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu
> *percpu)
> +{
> + if (conf->level == 6 && !percpu->spare_page)
> + percpu->spare_page = alloc_page(GFP_KERNEL);
> + if (!percpu->scribble)
> + percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
> +
> + if (!percpu->scribble || (conf->level == 6 && !percpu->spare_page)) {
> + free_scratch_buffer(conf, percpu);
> + return -ENOMEM;
> + }
> +
> + return 0;
> +}
> +
> static void raid5_free_percpu(struct r5conf *conf)
> {
> - struct raid5_percpu *percpu;
> unsigned long cpu;
>
> if (!conf->percpu)
> return;
>
> - get_online_cpus();
> - for_each_possible_cpu(cpu) {
> - percpu = per_cpu_ptr(conf->percpu, cpu);
> - safe_put_page(percpu->spare_page);
> - kfree(percpu->scribble);
> - }
> #ifdef CONFIG_HOTPLUG_CPU
> unregister_cpu_notifier(>cpu_notify);
> #endif
> +
> + get_online_cpus();
> + for_each_possible_cpu(cpu)
> + free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
> put_online_cpus();
>
> free_percpu(conf->percpu);
> @@ -5557,15 +5577,7 @@ static int raid456_cpu_notify(struct notifier_block
> *nfb, unsigned long action,
> switch (action) {
> case CPU_UP_PREPARE:
> case CPU_UP_PREPARE_FROZEN:
> - if (conf->level == 6 && !percpu->spare_page)
> - percpu->spare_page = alloc_page(GFP_KERNEL);
> - if (!percpu->scribble)
> - percpu->scribble = kmalloc(conf->scribble_len,
> GFP_KERNEL);
> -
> - if (!percpu->scribble ||
> - (conf->level == 6 && !percpu->spare_page)) {
> - safe_put_page(percpu->spare_page);
> - kfree(percpu->scribble);
> + if (alloc_scratch_buffer(conf, percpu)) {
> pr_err("%s: failed memory allocation for cpu%ld\n",
> __func__, cpu);
> return notifier_from_errno(-ENOMEM);
> @@ -5573,10 +5585,7 @@ static int raid456_cpu_notify(struct notifier_block
> *nfb, unsigned long action,
> break;
> case CPU_DEAD:
> case CPU_DEAD_FROZEN:
> - safe_put_page(percpu->spare_page);
> - kfree(percpu->scribble);
> - percpu->spare_page = NULL;
> - percpu->scribble = NULL;
> + free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
> break;
> default:
> break;
> @@ -5588,40 +5597,29 @@ static int raid456_cpu_notify(struct notifier_block
> *nfb, unsigned long action,
> static int raid5_alloc_percpu(struct r5conf *conf)
>
[PATCH 45/51] md, raid5: Fix CPU hotplug callback registration
From: Oleg Nesterov
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Interestingly, the raid5 code can actually prevent double initialization and
hence can use the following simplified form of callback registration:
register_cpu_notifier(_cpu_notifier);
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
put_online_cpus();
A hotplug operation that occurs between registering the notifier and calling
get_online_cpus(), won't disrupt anything, because the code takes care to
perform the memory allocations only once.
So reorganize the code in raid5 this way to fix the deadlock with callback
registration.
Cc: Neil Brown
Cc: linux-r...@vger.kernel.org
Cc: sta...@vger.kernel.org
[Srivatsa: Fixed the unregister_cpu_notifier() deadlock, added the
free_scratch_buffer() helper to condense code further and wrote the changelog.]
Signed-off-by: Srivatsa S. Bhat
---
drivers/md/raid5.c | 90 +---
1 file changed, 44 insertions(+), 46 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index f1feade..16f5c21 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5514,23 +5514,43 @@ raid5_size(struct mddev *mddev, sector_t sectors, int
raid_disks)
return sectors * (raid_disks - conf->max_degraded);
}
+static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu
*percpu)
+{
+ safe_put_page(percpu->spare_page);
+ kfree(percpu->scribble);
+ percpu->spare_page = NULL;
+ percpu->scribble = NULL;
+}
+
+static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu
*percpu)
+{
+ if (conf->level == 6 && !percpu->spare_page)
+ percpu->spare_page = alloc_page(GFP_KERNEL);
+ if (!percpu->scribble)
+ percpu->scribble = kmalloc(conf->scribble_len, GFP_KERNEL);
+
+ if (!percpu->scribble || (conf->level == 6 && !percpu->spare_page)) {
+ free_scratch_buffer(conf, percpu);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
static void raid5_free_percpu(struct r5conf *conf)
{
- struct raid5_percpu *percpu;
unsigned long cpu;
if (!conf->percpu)
return;
- get_online_cpus();
- for_each_possible_cpu(cpu) {
- percpu = per_cpu_ptr(conf->percpu, cpu);
- safe_put_page(percpu->spare_page);
- kfree(percpu->scribble);
- }
#ifdef CONFIG_HOTPLUG_CPU
unregister_cpu_notifier(>cpu_notify);
#endif
+
+ get_online_cpus();
+ for_each_possible_cpu(cpu)
+ free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
put_online_cpus();
free_percpu(conf->percpu);
@@ -5557,15 +5577,7 @@ static int raid456_cpu_notify(struct notifier_block
*nfb, unsigned long action,
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- if (conf->level == 6 && !percpu->spare_page)
- percpu->spare_page = alloc_page(GFP_KERNEL);
- if (!percpu->scribble)
- percpu->scribble = kmalloc(conf->scribble_len,
GFP_KERNEL);
-
- if (!percpu->scribble ||
- (conf->level == 6 && !percpu->spare_page)) {
- safe_put_page(percpu->spare_page);
- kfree(percpu->scribble);
+ if (alloc_scratch_buffer(conf, percpu)) {
pr_err("%s: failed memory allocation for cpu%ld\n",
__func__, cpu);
return notifier_from_errno(-ENOMEM);
@@ -5573,10 +5585,7 @@ static int raid456_cpu_notify(struct notifier_block
*nfb, unsigned long action,
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
- safe_put_page(percpu->spare_page);
- kfree(percpu->scribble);
- percpu->spare_page = NULL;
- percpu->scribble = NULL;
+ free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
break;
default:
break;
@@ -5588,40 +5597,29 @@ static int raid456_cpu_notify(struct notifier_block
*nfb, unsigned long action,
static int raid5_alloc_percpu(struct r5conf *conf)
{
unsigned long cpu;
- struct page *spare_page;
- struct raid5_percpu __percpu *allcpus;
- void *scribble;
- int err;
+ int err = 0;
- allcpus = alloc_percpu(struct
[PATCH 45/51] md, raid5: Fix CPU hotplug callback registration
From: Oleg Nesterov o...@redhat.com
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Interestingly, the raid5 code can actually prevent double initialization and
hence can use the following simplified form of callback registration:
register_cpu_notifier(foobar_cpu_notifier);
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
put_online_cpus();
A hotplug operation that occurs between registering the notifier and calling
get_online_cpus(), won't disrupt anything, because the code takes care to
perform the memory allocations only once.
So reorganize the code in raid5 this way to fix the deadlock with callback
registration.
Cc: Neil Brown ne...@suse.de
Cc: linux-r...@vger.kernel.org
Cc: sta...@vger.kernel.org
[Srivatsa: Fixed the unregister_cpu_notifier() deadlock, added the
free_scratch_buffer() helper to condense code further and wrote the changelog.]
Signed-off-by: Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com
---
drivers/md/raid5.c | 90 +---
1 file changed, 44 insertions(+), 46 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index f1feade..16f5c21 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5514,23 +5514,43 @@ raid5_size(struct mddev *mddev, sector_t sectors, int
raid_disks)
return sectors * (raid_disks - conf-max_degraded);
}
+static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu
*percpu)
+{
+ safe_put_page(percpu-spare_page);
+ kfree(percpu-scribble);
+ percpu-spare_page = NULL;
+ percpu-scribble = NULL;
+}
+
+static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu
*percpu)
+{
+ if (conf-level == 6 !percpu-spare_page)
+ percpu-spare_page = alloc_page(GFP_KERNEL);
+ if (!percpu-scribble)
+ percpu-scribble = kmalloc(conf-scribble_len, GFP_KERNEL);
+
+ if (!percpu-scribble || (conf-level == 6 !percpu-spare_page)) {
+ free_scratch_buffer(conf, percpu);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
static void raid5_free_percpu(struct r5conf *conf)
{
- struct raid5_percpu *percpu;
unsigned long cpu;
if (!conf-percpu)
return;
- get_online_cpus();
- for_each_possible_cpu(cpu) {
- percpu = per_cpu_ptr(conf-percpu, cpu);
- safe_put_page(percpu-spare_page);
- kfree(percpu-scribble);
- }
#ifdef CONFIG_HOTPLUG_CPU
unregister_cpu_notifier(conf-cpu_notify);
#endif
+
+ get_online_cpus();
+ for_each_possible_cpu(cpu)
+ free_scratch_buffer(conf, per_cpu_ptr(conf-percpu, cpu));
put_online_cpus();
free_percpu(conf-percpu);
@@ -5557,15 +5577,7 @@ static int raid456_cpu_notify(struct notifier_block
*nfb, unsigned long action,
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- if (conf-level == 6 !percpu-spare_page)
- percpu-spare_page = alloc_page(GFP_KERNEL);
- if (!percpu-scribble)
- percpu-scribble = kmalloc(conf-scribble_len,
GFP_KERNEL);
-
- if (!percpu-scribble ||
- (conf-level == 6 !percpu-spare_page)) {
- safe_put_page(percpu-spare_page);
- kfree(percpu-scribble);
+ if (alloc_scratch_buffer(conf, percpu)) {
pr_err(%s: failed memory allocation for cpu%ld\n,
__func__, cpu);
return notifier_from_errno(-ENOMEM);
@@ -5573,10 +5585,7 @@ static int raid456_cpu_notify(struct notifier_block
*nfb, unsigned long action,
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
- safe_put_page(percpu-spare_page);
- kfree(percpu-scribble);
- percpu-spare_page = NULL;
- percpu-scribble = NULL;
+ free_scratch_buffer(conf, per_cpu_ptr(conf-percpu, cpu));
break;
default:
break;
@@ -5588,40 +5597,29 @@ static int raid456_cpu_notify(struct notifier_block
*nfb, unsigned long action,
static int raid5_alloc_percpu(struct r5conf *conf)
{
unsigned long cpu;
- struct page *spare_page;
- struct raid5_percpu __percpu *allcpus;
- void *scribble;
- int err;
+ int err = 0;
- allcpus =
Re: [PATCH 45/51] md, raid5: Fix CPU hotplug callback registration
On Thu, 06 Feb 2014 03:42:45 +0530 Srivatsa S. Bhat
srivatsa.b...@linux.vnet.ibm.com wrote:
From: Oleg Nesterov o...@redhat.com
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
Interestingly, the raid5 code can actually prevent double initialization and
hence can use the following simplified form of callback registration:
register_cpu_notifier(foobar_cpu_notifier);
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
put_online_cpus();
A hotplug operation that occurs between registering the notifier and calling
get_online_cpus(), won't disrupt anything, because the code takes care to
perform the memory allocations only once.
So reorganize the code in raid5 this way to fix the deadlock with callback
registration.
Cc: Neil Brown ne...@suse.de
Cc: linux-r...@vger.kernel.org
Cc: sta...@vger.kernel.org
[Srivatsa: Fixed the unregister_cpu_notifier() deadlock, added the
free_scratch_buffer() helper to condense code further and wrote the
changelog.]
Signed-off-by: Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com
---
drivers/md/raid5.c | 90
+---
1 file changed, 44 insertions(+), 46 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index f1feade..16f5c21 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5514,23 +5514,43 @@ raid5_size(struct mddev *mddev, sector_t sectors, int
raid_disks)
return sectors * (raid_disks - conf-max_degraded);
}
+static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu
*percpu)
+{
+ safe_put_page(percpu-spare_page);
+ kfree(percpu-scribble);
+ percpu-spare_page = NULL;
+ percpu-scribble = NULL;
+}
+
+static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu
*percpu)
+{
+ if (conf-level == 6 !percpu-spare_page)
+ percpu-spare_page = alloc_page(GFP_KERNEL);
+ if (!percpu-scribble)
+ percpu-scribble = kmalloc(conf-scribble_len, GFP_KERNEL);
+
+ if (!percpu-scribble || (conf-level == 6 !percpu-spare_page)) {
+ free_scratch_buffer(conf, percpu);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
static void raid5_free_percpu(struct r5conf *conf)
{
- struct raid5_percpu *percpu;
unsigned long cpu;
if (!conf-percpu)
return;
- get_online_cpus();
- for_each_possible_cpu(cpu) {
- percpu = per_cpu_ptr(conf-percpu, cpu);
- safe_put_page(percpu-spare_page);
- kfree(percpu-scribble);
- }
#ifdef CONFIG_HOTPLUG_CPU
unregister_cpu_notifier(conf-cpu_notify);
#endif
+
+ get_online_cpus();
+ for_each_possible_cpu(cpu)
+ free_scratch_buffer(conf, per_cpu_ptr(conf-percpu, cpu));
put_online_cpus();
free_percpu(conf-percpu);
@@ -5557,15 +5577,7 @@ static int raid456_cpu_notify(struct notifier_block
*nfb, unsigned long action,
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- if (conf-level == 6 !percpu-spare_page)
- percpu-spare_page = alloc_page(GFP_KERNEL);
- if (!percpu-scribble)
- percpu-scribble = kmalloc(conf-scribble_len,
GFP_KERNEL);
-
- if (!percpu-scribble ||
- (conf-level == 6 !percpu-spare_page)) {
- safe_put_page(percpu-spare_page);
- kfree(percpu-scribble);
+ if (alloc_scratch_buffer(conf, percpu)) {
pr_err(%s: failed memory allocation for cpu%ld\n,
__func__, cpu);
return notifier_from_errno(-ENOMEM);
@@ -5573,10 +5585,7 @@ static int raid456_cpu_notify(struct notifier_block
*nfb, unsigned long action,
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
- safe_put_page(percpu-spare_page);
- kfree(percpu-scribble);
- percpu-spare_page = NULL;
- percpu-scribble = NULL;
+ free_scratch_buffer(conf, per_cpu_ptr(conf-percpu, cpu));
break;
default:
break;
@@ -5588,40 +5597,29 @@ static int raid456_cpu_notify(struct notifier_block
*nfb, unsigned long action,
static int raid5_alloc_percpu(struct r5conf *conf)
{
unsigned long cpu;
- struct page *spare_page;
- struct
