2020-10-01 07:02:06

by Coly Li

[permalink] [raw]
Subject: [PATCH v2] mmc: core: don't set limits.discard_granularity as 0

In mmc_queue_setup_discard() the mmc driver queue's discard_granularity
might be set as 0 (when card->pref_erase > max_discard) while the mmc
device still declares to support discard operation. This is buggy and
triggered the following kernel warning message,

WARNING: CPU: 0 PID: 135 at __blkdev_issue_discard+0x200/0x294
CPU: 0 PID: 135 Comm: f2fs_discard-17 Not tainted 5.9.0-rc6 #1
Hardware name: Google Kevin (DT)
pstate: 00000005 (nzcv daif -PAN -UAO BTYPE=--)
pc : __blkdev_issue_discard+0x200/0x294
lr : __blkdev_issue_discard+0x54/0x294
sp : ffff800011dd3b10
x29: ffff800011dd3b10 x28: 0000000000000000 x27: ffff800011dd3cc4 x26: ffff800011dd3e18 x25: 000000000004e69b x24: 0000000000000c40 x23: ffff0000f1deaaf0 x22: ffff0000f2849200 x21: 00000000002734d8 x20: 0000000000000008 x19: 0000000000000000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000394 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 00000000000008b0 x9 : ffff800011dd3cb0 x8 : 000000000004e69b x7 : 0000000000000000 x6 : ffff0000f1926400 x5 : ffff0000f1940800 x4 : 0000000000000000 x3 : 0000000000000c40 x2 : 0000000000000008 x1 : 00000000002734d8 x0 : 0000000000000000 Call trace:
__blkdev_issue_discard+0x200/0x294
__submit_discard_cmd+0x128/0x374
__issue_discard_cmd_orderly+0x188/0x244
__issue_discard_cmd+0x2e8/0x33c
issue_discard_thread+0xe8/0x2f0
kthread+0x11c/0x120
ret_from_fork+0x10/0x1c
---[ end trace e4c8023d33dfe77a ]---

This patch fixes the issue by setting discard_granularity as SECTOR_SIZE
instead of 0 when (card->pref_erase > max_discard) is true. Now no more
complain from __blkdev_issue_discard() for the improper value of discard
granularity.

This issue is explored after commit b35fd7422c2f ("block: check queue's
limits.discard_granularity in __blkdev_issue_discard()"), therefore add
a "Fixes:" tag for the commit to make sure people won't miss this patch
after applying the change of __blkdev_issue_discard().

Fixes: b35fd7422c2f ("block: check queue's limits.discard_granularity in __blkdev_issue_discard()").
Reported-by: Vicente Bergas <[email protected]>
Signed-off-by: Coly Li <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ulf Hansson <[email protected]>
---
Changelog,
v2, change commit id of the Fixes tag.
v1, initial version.

drivers/mmc/core/queue.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 6c022ef0f84d..350d0cc4ee62 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -190,7 +190,7 @@ static void mmc_queue_setup_discard(struct request_queue *q,
q->limits.discard_granularity = card->pref_erase << 9;
/* granularity must not be greater than max. discard */
if (card->pref_erase > max_discard)
- q->limits.discard_granularity = 0;
+ q->limits.discard_granularity = SECTOR_SIZE;
if (mmc_can_secure_erase_trim(card))
blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
}
--
2.26.2


2020-10-01 07:15:14

by Adrian Hunter

[permalink] [raw]
Subject: Re: [PATCH v2] mmc: core: don't set limits.discard_granularity as 0

On 1/10/20 9:59 am, Coly Li wrote:
> In mmc_queue_setup_discard() the mmc driver queue's discard_granularity
> might be set as 0 (when card->pref_erase > max_discard) while the mmc
> device still declares to support discard operation. This is buggy and
> triggered the following kernel warning message,
>
> WARNING: CPU: 0 PID: 135 at __blkdev_issue_discard+0x200/0x294
> CPU: 0 PID: 135 Comm: f2fs_discard-17 Not tainted 5.9.0-rc6 #1
> Hardware name: Google Kevin (DT)
> pstate: 00000005 (nzcv daif -PAN -UAO BTYPE=--)
> pc : __blkdev_issue_discard+0x200/0x294
> lr : __blkdev_issue_discard+0x54/0x294
> sp : ffff800011dd3b10
> x29: ffff800011dd3b10 x28: 0000000000000000 x27: ffff800011dd3cc4 x26: ffff800011dd3e18 x25: 000000000004e69b x24: 0000000000000c40 x23: ffff0000f1deaaf0 x22: ffff0000f2849200 x21: 00000000002734d8 x20: 0000000000000008 x19: 0000000000000000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000394 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 00000000000008b0 x9 : ffff800011dd3cb0 x8 : 000000000004e69b x7 : 0000000000000000 x6 : ffff0000f1926400 x5 : ffff0000f1940800 x4 : 0000000000000000 x3 : 0000000000000c40 x2 : 0000000000000008 x1 : 00000000002734d8 x0 : 0000000000000000 Call trace:
> __blkdev_issue_discard+0x200/0x294
> __submit_discard_cmd+0x128/0x374
> __issue_discard_cmd_orderly+0x188/0x244
> __issue_discard_cmd+0x2e8/0x33c
> issue_discard_thread+0xe8/0x2f0
> kthread+0x11c/0x120
> ret_from_fork+0x10/0x1c
> ---[ end trace e4c8023d33dfe77a ]---
>
> This patch fixes the issue by setting discard_granularity as SECTOR_SIZE
> instead of 0 when (card->pref_erase > max_discard) is true. Now no more
> complain from __blkdev_issue_discard() for the improper value of discard
> granularity.
>
> This issue is explored after commit b35fd7422c2f ("block: check queue's

explored -> exposed

> limits.discard_granularity in __blkdev_issue_discard()"), therefore add
> a "Fixes:" tag for the commit to make sure people won't miss this patch
> after applying the change of __blkdev_issue_discard().
>
> Fixes: b35fd7422c2f ("block: check queue's limits.discard_granularity in __blkdev_issue_discard()").

I thought you would keep the other fixes tag also

> Reported-by: Vicente Bergas <[email protected]>
> Signed-off-by: Coly Li <[email protected]>
> Cc: Adrian Hunter <[email protected]>
> Cc: Ulf Hansson <[email protected]>

Otherwise:

Acked-by: Adrian Hunter <[email protected]>

> ---
> Changelog,
> v2, change commit id of the Fixes tag.
> v1, initial version.
>
> drivers/mmc/core/queue.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
> index 6c022ef0f84d..350d0cc4ee62 100644
> --- a/drivers/mmc/core/queue.c
> +++ b/drivers/mmc/core/queue.c
> @@ -190,7 +190,7 @@ static void mmc_queue_setup_discard(struct request_queue *q,
> q->limits.discard_granularity = card->pref_erase << 9;
> /* granularity must not be greater than max. discard */
> if (card->pref_erase > max_discard)
> - q->limits.discard_granularity = 0;
> + q->limits.discard_granularity = SECTOR_SIZE;
> if (mmc_can_secure_erase_trim(card))
> blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
> }
>

2020-10-01 07:19:29

by Coly Li

[permalink] [raw]
Subject: Re: [PATCH v2] mmc: core: don't set limits.discard_granularity as 0

On 2020/10/1 15:13, Adrian Hunter wrote:
> On 1/10/20 9:59 am, Coly Li wrote:
>> In mmc_queue_setup_discard() the mmc driver queue's discard_granularity
>> might be set as 0 (when card->pref_erase > max_discard) while the mmc
>> device still declares to support discard operation. This is buggy and
>> triggered the following kernel warning message,
>>
>> WARNING: CPU: 0 PID: 135 at __blkdev_issue_discard+0x200/0x294
>> CPU: 0 PID: 135 Comm: f2fs_discard-17 Not tainted 5.9.0-rc6 #1
>> Hardware name: Google Kevin (DT)
>> pstate: 00000005 (nzcv daif -PAN -UAO BTYPE=--)
>> pc : __blkdev_issue_discard+0x200/0x294
>> lr : __blkdev_issue_discard+0x54/0x294
>> sp : ffff800011dd3b10
>> x29: ffff800011dd3b10 x28: 0000000000000000 x27: ffff800011dd3cc4 x26: ffff800011dd3e18 x25: 000000000004e69b x24: 0000000000000c40 x23: ffff0000f1deaaf0 x22: ffff0000f2849200 x21: 00000000002734d8 x20: 0000000000000008 x19: 0000000000000000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 0000000000000394 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 00000000000008b0 x9 : ffff800011dd3cb0 x8 : 000000000004e69b x7 : 0000000000000000 x6 : ffff0000f1926400 x5 : ffff0000f1940800 x4 : 0000000000000000 x3 : 0000000000000c40 x2 : 0000000000000008 x1 : 00000000002734d8 x0 : 0000000000000000 Call trace:
>> __blkdev_issue_discard+0x200/0x294
>> __submit_discard_cmd+0x128/0x374
>> __issue_discard_cmd_orderly+0x188/0x244
>> __issue_discard_cmd+0x2e8/0x33c
>> issue_discard_thread+0xe8/0x2f0
>> kthread+0x11c/0x120
>> ret_from_fork+0x10/0x1c
>> ---[ end trace e4c8023d33dfe77a ]---
>>
>> This patch fixes the issue by setting discard_granularity as SECTOR_SIZE
>> instead of 0 when (card->pref_erase > max_discard) is true. Now no more
>> complain from __blkdev_issue_discard() for the improper value of discard
>> granularity.
>>
>> This issue is explored after commit b35fd7422c2f ("block: check queue's
>
> explored -> exposed
>
>> limits.discard_granularity in __blkdev_issue_discard()"), therefore add
>> a "Fixes:" tag for the commit to make sure people won't miss this patch
>> after applying the change of __blkdev_issue_discard().
>>
>> Fixes: b35fd7422c2f ("block: check queue's limits.discard_granularity in __blkdev_issue_discard()").
>
> I thought you would keep the other fixes tag also
>
>> Reported-by: Vicente Bergas <[email protected]>
>> Signed-off-by: Coly Li <[email protected]>
>> Cc: Adrian Hunter <[email protected]>
>> Cc: Ulf Hansson <[email protected]>
>
> Otherwise:
>
> Acked-by: Adrian Hunter <[email protected]>

Copied, and thanks for your comments.

Coly Li