RE: [PATCH] csiostor:Fix locking issues in the function csio_scsim_cleanup_io_lnode

From: Praveen Madhavan
Date: Fri Sep 04 2015 - 09:12:03 EST


csio_scsim_cleanup_io_lnode always called with spin_lock_irq held.
Please refer:
csio_attr.c:624: csio_scsim_cleanup_io_lnode(csio_hw_to_scsim(hw), ln);
csio_attr.c:649: csio_scsim_cleanup_io_lnode(csio_hw_to_scsim(hw), ln);

-----Original Message-----
From: linux-scsi-owner@xxxxxxxxxxxxxxx [mailto:linux-scsi-owner@xxxxxxxxxxxxxxx] On Behalf Of Anish Bhatt
Sent: Thursday, September 03, 2015 7:07 AM
To: Nicholas Krause; JBottomley@xxxxxxxx
Cc: hare@xxxxxxx; michaelc@xxxxxxxxxxx; davem@xxxxxxxxxxxxx; Hariprasad S; linux-scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: RE: [PATCH] csiostor:Fix locking issues in the function csio_scsim_cleanup_io_lnode

> -----Original Message-----
> From: Nicholas Krause [mailto:xerofoify@xxxxxxxxx]
> Sent: Wednesday, September 2, 2015 10:36 AM
> To: JBottomley@xxxxxxxx
> Cc: hare@xxxxxxx; michaelc@xxxxxxxxxxx; davem@xxxxxxxxxxxxx; Anish
> Bhatt; Hariprasad S; linux-scsi@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH] csiostor:Fix locking issues in the function
> csio_scsim_cleanup_io_lnode
>
> This fixes locking issues in the function csio_scsim_cleanup_io_lnode
> by locking around the call to the function csio_csci_gather_active_ios
> with the function pair spin_lock_irq/spin_unlock_irq as any function
> calling this particular function must do in order to avoid concurrent
> threads of execution on the passed structure pointer of type csio_hw
> as this structure pointer can be shared across mutliple threads in the kernel.
>
> Signed-off-by: Nicholas Krause <xerofoify@xxxxxxxxx>
> ---
> drivers/scsi/csiostor/csio_scsi.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/scsi/csiostor/csio_scsi.c
> b/drivers/scsi/csiostor/csio_scsi.c
> index 2c4562d..c318855 100644
> --- a/drivers/scsi/csiostor/csio_scsi.c
> +++ b/drivers/scsi/csiostor/csio_scsi.c
> @@ -1327,7 +1327,9 @@ csio_scsim_cleanup_io_lnode(struct csio_scsim
> *scm, struct csio_lnode *ln)
> sld.level = CSIO_LEV_LNODE;
> sld.lnode = ln;
> INIT_LIST_HEAD(&ln->cmpl_q);
> + spin_lock_irq(&hw->lock);
> csio_scsi_gather_active_ios(scm, &sld, &ln->cmpl_q);
> + spin_unlock_irq(&hw->lock);
>
> /* No I/Os pending on this lnode */
> if (list_empty(&ln->cmpl_q))
> --
> 2.1.4

Acked-By: Anish Bhatt <anish@xxxxxxxxxxx>
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