[PATCH] scsi: restart list search after unlock in scsi_remove_target

2015-10-19 Thread Christoph Hellwig
When dropping a lock while iterating a list we must restart the search as other threads could have manipulated the list under us. Without this we can get stuck in an endless loop. Reported-by: Johannes Thumshirn Signed-off-by: Christoph Hellwig diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/

Re: [PATCH] scsi: restart list search after unlock in scsi_remove_target

2015-10-19 Thread Bart Van Assche
On 10/19/2015 07:35 AM, Christoph Hellwig wrote: When dropping a lock while iterating a list we must restart the search as other threads could have manipulated the list under us. Without this we can get stuck in an endless loop. Hello Christoph, Thanks for looking into this. However, I think

Re: [PATCH] scsi: restart list search after unlock in scsi_remove_target

2015-10-19 Thread Christoph Hellwig
On Mon, Oct 19, 2015 at 08:36:23AM -0700, Bart Van Assche wrote: > Thanks for looking into this. However, I think we need a motivation in the > patch description why this patch does not reintroduce the soft lockup > documented in patch "scsi_remove_target: fix softlockup regression on hot > remo

Re: [PATCH] scsi: restart list search after unlock in scsi_remove_target

2015-10-19 Thread James Bottomley
On Mon, 2015-10-19 at 17:56 +0200, Christoph Hellwig wrote: > On Mon, Oct 19, 2015 at 08:36:23AM -0700, Bart Van Assche wrote: > > Thanks for looking into this. However, I think we need a motivation in the > > patch description why this patch does not reintroduce the soft lockup > > documented in

Re: [PATCH] scsi: restart list search after unlock in scsi_remove_target

2015-10-19 Thread Dan Williams
On Mon, Oct 19, 2015 at 8:56 AM, Christoph Hellwig wrote: > On Mon, Oct 19, 2015 at 08:36:23AM -0700, Bart Van Assche wrote: >> Thanks for looking into this. However, I think we need a motivation in the >> patch description why this patch does not reintroduce the soft lockup >> documented in patch

Re: [PATCH] scsi: restart list search after unlock in scsi_remove_target

2015-10-26 Thread Johannes Thumshirn
On Mon, 2015-10-19 at 16:35 +0200, Christoph Hellwig wrote: > When dropping a lock while iterating a list we must restart the > search > as other threads could have manipulated the list under us.  Without > this > we can get stuck in an endless loop. > > Reported-by: Johannes Thumshirn > Signed-o

Re: [PATCH] scsi: restart list search after unlock in scsi_remove_target

2015-10-27 Thread Johannes Thumshirn
On Mon, 2015-10-19 at 16:35 +0200, Christoph Hellwig wrote: > When dropping a lock while iterating a list we must restart the > search > as other threads could have manipulated the list under us.  Without > this > we can get stuck in an endless loop. > > Reported-by: Johannes Thumshirn > Signed-o

Re: [PATCH] scsi: restart list search after unlock in scsi_remove_target

2015-10-27 Thread Bart Van Assche
e patch below, which is a variant of Christoph's patch ? Thanks, Bart. [PATCH] scsi: Restart list search after unlock in scsi_remove_target When dropping a lock while iterating a list we must restart the search as other threads could have manipulated the list under us. Without this we ca

Re: [PATCH] scsi: restart list search after unlock in scsi_remove_target

2015-10-30 Thread Johannes Thumshirn
Hi Bart, On Tue, 2015-10-27 at 13:14 -0700, Bart Van Assche wrote: > On 10/26/2015 01:35 AM, Johannes Thumshirn wrote: > > I haven't heard anything from the original reporter of the lockup > > but > > my test's went all O.K., so > > > > Tested-by: Johannes Thumshirn > > Reviewed-by: Johannes Thum