RE: [PATCH v2] [SCSI] mpt2sas: fix double mutex lock in NON_BLOCKING state

2012-08-29 Thread Reddy, Sreekanth 
James,

This patch seem to be fine. Please consider this patch as Acked-by: "Sreekanth 
Reddy" 

Regards,
Sreekanth.

> -Original Message-
> From: Alexey Khoroshilov [mailto:khoroshi...@ispras.ru]
> Sent: Tuesday, August 28, 2012 8:08 PM
> To: James E.J. Bottomley
> Cc: Alexey Khoroshilov; linux-s...@vger.kernel.org; Nandigama,
> Nagalakshmi; Reddy, Sreekanth; linux-kernel@vger.kernel.org; ldv-
> proj...@ispras.ru
> Subject: [PATCH v2] [SCSI] mpt2sas: fix double mutex lock in
> NON_BLOCKING state
> 
> If state is NON_BLOCKING and mutex_trylock is succeed,
> the control flow goes to mutex_lock_interruptible() that is a deadlock.
> 
> The previous version of the patch becomes obsolete after
> code movement in commit 913809f6.
> 
> Found by Linux Driver Verification project (linuxtesting.org).
> 
> Signed-off-by: Alexey Khoroshilov 
> ---
>  drivers/scsi/mpt2sas/mpt2sas_ctl.c |6 --
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/mpt2sas/mpt2sas_ctl.c
> b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
> index 49bdd2d..d29ea56 100644
> --- a/drivers/scsi/mpt2sas/mpt2sas_ctl.c
> +++ b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
> @@ -2181,8 +2181,10 @@ _ctl_ioctl_main(struct file *file, unsigned int
> cmd, void __user *arg,
>   return -EAGAIN;
> 
>   state = (file->f_flags & O_NONBLOCK) ? NON_BLOCKING : BLOCKING;
> - if (state == NON_BLOCKING && !mutex_trylock(
> >ctl_cmds.mutex))
> - return -EAGAIN;
> + if (state == NON_BLOCKING) {
> + if (!mutex_trylock(>ctl_cmds.mutex))
> + return -EAGAIN;
> + }
>   else if (mutex_lock_interruptible(>ctl_cmds.mutex))
>   return -ERESTARTSYS;
> 
> --
> 1.7.9.5

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RE: [PATCH v2] [SCSI] mpt2sas: fix double mutex lock in NON_BLOCKING state

2012-08-29 Thread Reddy, Sreekanth 
James,

This patch seem to be fine. Please consider this patch as Acked-by: Sreekanth 
Reddy sreekanth.re...@lsi.com

Regards,
Sreekanth.

 -Original Message-
 From: Alexey Khoroshilov [mailto:khoroshi...@ispras.ru]
 Sent: Tuesday, August 28, 2012 8:08 PM
 To: James E.J. Bottomley
 Cc: Alexey Khoroshilov; linux-s...@vger.kernel.org; Nandigama,
 Nagalakshmi; Reddy, Sreekanth; linux-kernel@vger.kernel.org; ldv-
 proj...@ispras.ru
 Subject: [PATCH v2] [SCSI] mpt2sas: fix double mutex lock in
 NON_BLOCKING state
 
 If state is NON_BLOCKING and mutex_trylock is succeed,
 the control flow goes to mutex_lock_interruptible() that is a deadlock.
 
 The previous version of the patch becomes obsolete after
 code movement in commit 913809f6.
 
 Found by Linux Driver Verification project (linuxtesting.org).
 
 Signed-off-by: Alexey Khoroshilov khoroshi...@ispras.ru
 ---
  drivers/scsi/mpt2sas/mpt2sas_ctl.c |6 --
  1 file changed, 4 insertions(+), 2 deletions(-)
 
 diff --git a/drivers/scsi/mpt2sas/mpt2sas_ctl.c
 b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
 index 49bdd2d..d29ea56 100644
 --- a/drivers/scsi/mpt2sas/mpt2sas_ctl.c
 +++ b/drivers/scsi/mpt2sas/mpt2sas_ctl.c
 @@ -2181,8 +2181,10 @@ _ctl_ioctl_main(struct file *file, unsigned int
 cmd, void __user *arg,
   return -EAGAIN;
 
   state = (file-f_flags  O_NONBLOCK) ? NON_BLOCKING : BLOCKING;
 - if (state == NON_BLOCKING  !mutex_trylock(ioc-
 ctl_cmds.mutex))
 - return -EAGAIN;
 + if (state == NON_BLOCKING) {
 + if (!mutex_trylock(ioc-ctl_cmds.mutex))
 + return -EAGAIN;
 + }
   else if (mutex_lock_interruptible(ioc-ctl_cmds.mutex))
   return -ERESTARTSYS;
 
 --
 1.7.9.5

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