* [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
@ 2018-05-24 13:26 Waiman Long
2018-06-19 23:09 ` Waiman Long
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Waiman Long @ 2018-05-24 13:26 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra, Thomas Gleixner
Cc: linux-kernel, Davidlohr Bueso, Dan Williams, Arnd Bergmann,
linux-nfs, Waiman Long
It was found that the use of up_read_non_owner() in NFS was causing
the following warning when DEBUG_RWSEMS was configured.
DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0)))
Looking into the rwsem.c file, it was discovered that the corresponding
down_read_non_owner() function was not setting the owner field properly.
This is fixed now, and the warning should be gone.
Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/locking/rwsem.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index bc1e507..776308d 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semaphore *sem)
might_sleep();
__down_read(sem);
+ rwsem_set_reader_owned(sem);
}
EXPORT_SYMBOL(down_read_non_owner);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
2018-05-24 13:26 [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS Waiman Long
@ 2018-06-19 23:09 ` Waiman Long
2018-06-20 5:49 ` Schenk, Gavin
2018-06-20 9:17 ` Peter Zijlstra
2018-06-20 9:33 ` [tip:locking/urgent] " tip-bot for Waiman Long
2 siblings, 1 reply; 6+ messages in thread
From: Waiman Long @ 2018-06-19 23:09 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra, Thomas Gleixner
Cc: linux-kernel, Davidlohr Bueso, Dan Williams, Arnd Bergmann,
linux-nfs, Uwe Kleine-König
On 05/24/2018 09:26 PM, Waiman Long wrote:
> It was found that the use of up_read_non_owner() in NFS was causing
> the following warning when DEBUG_RWSEMS was configured.
>
> DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0)))
>
> Looking into the rwsem.c file, it was discovered that the corresponding
> down_read_non_owner() function was not setting the owner field properly.
> This is fixed now, and the warning should be gone.
>
> Signed-off-by: Waiman Long <longman@redhat.com>
> ---
> kernel/locking/rwsem.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
> index bc1e507..776308d 100644
> --- a/kernel/locking/rwsem.c
> +++ b/kernel/locking/rwsem.c
> @@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semaphore *sem)
> might_sleep();
> tch
> __down_read(sem);
> + rwsem_set_reader_owned(sem);
> }
>
> EXPORT_SYMBOL(down_read_non_owner);
Since the 4.18 merge window has been closed. Can that patch be merged
upstream?
Cheers,
Longman
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Customers.Eckelmann] [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
2018-06-19 23:09 ` Waiman Long
@ 2018-06-20 5:49 ` Schenk, Gavin
0 siblings, 0 replies; 6+ messages in thread
From: Schenk, Gavin @ 2018-06-20 5:49 UTC (permalink / raw)
To: tglx, longman, peterz, mingo
Cc: dan.j.williams, linux-kernel, u.kleine-koenig, linux-nfs, arnd, dave
Hi,
On Wed, 2018-06-20 at 07:09 +0800, Waiman Long wrote:
> On 05/24/2018 09:26 PM, Waiman Long wrote:
> > It was found that the use of up_read_non_owner() in NFS was causing
> > the following warning when DEBUG_RWSEMS was configured.
> >
> > DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0)))
> >
> > Looking into the rwsem.c file, it was discovered that the corresponding
> > down_read_non_owner() function was not setting the owner field properly.
> > This is fixed now, and the warning should be gone.
> >
> > Signed-off-by: Waiman Long <longman@redhat.com>
Tested-by: Gavin Schenk <g.schenk@eckelmann.de>
This fixes my reproducible locking splat when booting with nfsroot and changing password. Thank you!
Regards
Gavin Schenk
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Customers.Eckelmann] [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
@ 2018-06-20 5:49 ` Schenk, Gavin
0 siblings, 0 replies; 6+ messages in thread
From: Schenk, Gavin @ 2018-06-20 5:49 UTC (permalink / raw)
To: tglx, longman, peterz, mingo
Cc: dan.j.williams, linux-kernel, u.kleine-koenig, linux-nfs, arnd, dave
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IFRoYW5rIHlvdSENCg0KUmVnYXJkcw0KR2F2aW4gU2NoZW5rDQo=
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
2018-05-24 13:26 [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS Waiman Long
2018-06-19 23:09 ` Waiman Long
@ 2018-06-20 9:17 ` Peter Zijlstra
2018-06-20 9:33 ` [tip:locking/urgent] " tip-bot for Waiman Long
2 siblings, 0 replies; 6+ messages in thread
From: Peter Zijlstra @ 2018-06-20 9:17 UTC (permalink / raw)
To: Waiman Long
Cc: Ingo Molnar, Thomas Gleixner, linux-kernel, Davidlohr Bueso,
Dan Williams, Arnd Bergmann, linux-nfs
On Thu, May 24, 2018 at 09:26:38AM -0400, Waiman Long wrote:
> It was found that the use of up_read_non_owner() in NFS was causing
> the following warning when DEBUG_RWSEMS was configured.
>
> DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0)))
>
> Looking into the rwsem.c file, it was discovered that the corresponding
> down_read_non_owner() function was not setting the owner field properly.
> This is fixed now, and the warning should be gone.
>
> Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> kernel/locking/rwsem.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
> index bc1e507..776308d 100644
> --- a/kernel/locking/rwsem.c
> +++ b/kernel/locking/rwsem.c
> @@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semaphore *sem)
> might_sleep();
>
> __down_read(sem);
> + rwsem_set_reader_owned(sem);
> }
>
> EXPORT_SYMBOL(down_read_non_owner);
> --
> 1.8.3.1
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [tip:locking/urgent] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
2018-05-24 13:26 [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS Waiman Long
2018-06-19 23:09 ` Waiman Long
2018-06-20 9:17 ` Peter Zijlstra
@ 2018-06-20 9:33 ` tip-bot for Waiman Long
2 siblings, 0 replies; 6+ messages in thread
From: tip-bot for Waiman Long @ 2018-06-20 9:33 UTC (permalink / raw)
To: linux-tip-commits
Cc: dave, arnd, linux-kernel, g.schenk, peterz, tglx, longman, mingo,
hpa, dan.j.williams
Commit-ID: 03eeafdd9ab06a770d42c2b264d50dff7e2f4eee
Gitweb: https://git.kernel.org/tip/03eeafdd9ab06a770d42c2b264d50dff7e2f4eee
Author: Waiman Long <longman@redhat.com>
AuthorDate: Thu, 24 May 2018 09:26:38 -0400
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 20 Jun 2018 11:29:23 +0200
locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
It was found that the use of up_read_non_owner() in NFS was causing
the following warning when DEBUG_RWSEMS was configured.
DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0)))
Looking into the rwsem.c file, it was discovered that the corresponding
down_read_non_owner() function was not setting the owner field properly.
This is fixed now, and the warning should be gone.
Fixes: 5149cbac4235 ("locking/rwsem: Add DEBUG_RWSEMS to look for lock/unlock mismatches")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Gavin Schenk <g.schenk@eckelmann.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-nfs@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1527168398-4291-1-git-send-email-longman@redhat.com
---
kernel/locking/rwsem.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index bc1e507be9ff..776308d2fa9e 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semaphore *sem)
might_sleep();
__down_read(sem);
+ rwsem_set_reader_owned(sem);
}
EXPORT_SYMBOL(down_read_non_owner);
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-06-20 9:34 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-05-24 13:26 [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS Waiman Long
2018-06-19 23:09 ` Waiman Long
2018-06-20 5:49 ` [Customers.Eckelmann] " Schenk, Gavin
2018-06-20 5:49 ` Schenk, Gavin
2018-06-20 9:17 ` Peter Zijlstra
2018-06-20 9:33 ` [tip:locking/urgent] " tip-bot for Waiman Long
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