* [PATCH] scsi: target: tcmu: Use GFP_NOIO while handling cmds or holding cmdr_lock
@ 2021-03-05 19:00 Bodo Stroesser
2021-03-06 22:23 ` michael.christie
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Bodo Stroesser @ 2021-03-05 19:00 UTC (permalink / raw)
To: linux-scsi, target-devel, Martin K. Petersen, Mike Christie
Cc: Bodo Stroesser
Especially when using tcmu with tcm_loop, memory allocations with
GFP_KERNEL for a LUN can cause write back to the same LUN.
So we have to use GFP_NOIO when allocation is done while handling
commands or while holding cmdr_lock.
Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
---
This patch is based on Martin's for-next branch plus my short
series "scsi: target: tcmu: Replace IDR and radix_tree with XArray"
See:
https://lore.kernel.org/linux-scsi/20210224185335.13844-1-bostroesser@gmail.com/
drivers/target/target_core_user.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index ada3ef982969..9e1b115cb032 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -518,7 +518,7 @@ static inline int tcmu_get_empty_block(struct tcmu_dev *udev,
if (!page)
goto err_alloc;
- if (xa_store(&udev->data_blocks, dbi, page, GFP_KERNEL))
+ if (xa_store(&udev->data_blocks, dbi, page, GFP_NOIO))
goto err_insert;
}
@@ -1272,7 +1272,7 @@ tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
- tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_KERNEL);
+ tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_NOIO);
if (!tmr)
goto unlock;
--
2.12.3
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] scsi: target: tcmu: Use GFP_NOIO while handling cmds or holding cmdr_lock
2021-03-05 19:00 [PATCH] scsi: target: tcmu: Use GFP_NOIO while handling cmds or holding cmdr_lock Bodo Stroesser
@ 2021-03-06 22:23 ` michael.christie
2021-03-10 2:36 ` Martin K. Petersen
2021-03-16 3:14 ` Martin K. Petersen
2 siblings, 0 replies; 4+ messages in thread
From: michael.christie @ 2021-03-06 22:23 UTC (permalink / raw)
To: Bodo Stroesser, linux-scsi, target-devel, Martin K. Petersen
On 3/5/21 1:00 PM, Bodo Stroesser wrote:
> Especially when using tcmu with tcm_loop, memory allocations with
> GFP_KERNEL for a LUN can cause write back to the same LUN.
>
> So we have to use GFP_NOIO when allocation is done while handling
> commands or while holding cmdr_lock.
>
> Signed-off-by: Bodo Stroesser <bostroesser@gmail.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] scsi: target: tcmu: Use GFP_NOIO while handling cmds or holding cmdr_lock
2021-03-05 19:00 [PATCH] scsi: target: tcmu: Use GFP_NOIO while handling cmds or holding cmdr_lock Bodo Stroesser
2021-03-06 22:23 ` michael.christie
@ 2021-03-10 2:36 ` Martin K. Petersen
2021-03-16 3:14 ` Martin K. Petersen
2 siblings, 0 replies; 4+ messages in thread
From: Martin K. Petersen @ 2021-03-10 2:36 UTC (permalink / raw)
To: Bodo Stroesser
Cc: linux-scsi, target-devel, Martin K. Petersen, Mike Christie
Bodo,
> Especially when using tcmu with tcm_loop, memory allocations with
> GFP_KERNEL for a LUN can cause write back to the same LUN.
Applied to 5.13/scsi-staging, thanks!
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] scsi: target: tcmu: Use GFP_NOIO while handling cmds or holding cmdr_lock
2021-03-05 19:00 [PATCH] scsi: target: tcmu: Use GFP_NOIO while handling cmds or holding cmdr_lock Bodo Stroesser
2021-03-06 22:23 ` michael.christie
2021-03-10 2:36 ` Martin K. Petersen
@ 2021-03-16 3:14 ` Martin K. Petersen
2 siblings, 0 replies; 4+ messages in thread
From: Martin K. Petersen @ 2021-03-16 3:14 UTC (permalink / raw)
To: linux-scsi, target-devel, Bodo Stroesser, Mike Christie
Cc: Martin K . Petersen
On Fri, 5 Mar 2021 20:00:09 +0100, Bodo Stroesser wrote:
> Especially when using tcmu with tcm_loop, memory allocations with
> GFP_KERNEL for a LUN can cause write back to the same LUN.
>
> So we have to use GFP_NOIO when allocation is done while handling
> commands or while holding cmdr_lock.
Applied to 5.13/scsi-queue, thanks!
[1/1] scsi: target: tcmu: Use GFP_NOIO while handling cmds or holding cmdr_lock
https://git.kernel.org/mkp/scsi/c/1080782f13e3
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-03-16 3:15 UTC | newest]
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2021-03-05 19:00 [PATCH] scsi: target: tcmu: Use GFP_NOIO while handling cmds or holding cmdr_lock Bodo Stroesser
2021-03-06 22:23 ` michael.christie
2021-03-10 2:36 ` Martin K. Petersen
2021-03-16 3:14 ` Martin K. Petersen
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