From: James Bottomley <[email protected]>
linux-v3.8-rc1 and later support for plug for blkdev_issue_discard with
commit 0cfbcafcae8b7364b5fa96c2b26ccde7a3a296a9
(block: add plug for blkdev_issue_discard )
For example,
1) DISCARD rq-1 with size size 4GB
2) DISCARD rq-2 with size size 1GB
If these 2 discard requests get merged, final request size will be 5GB.
In this case, request's __data_len field may overflow as it can store
max 4GB(unsigned int).
This issue was observed while doing mkfs.f2fs on 5GB SD card:
https://lkml.org/lkml/2013/4/1/292
Info: sector size = 512
Info: total sectors = 11370496 (in 512bytes)
Info: zone aligned segment0 blkaddr: 512
[ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
mkfs process gets stuck in D state and I see the following in the dmesg:
[ 257.789733] __end_that: dev mmcblk0: type=1, flags=122c8081
[ 257.789764] sector 4194304, nr/cnr 2981888/4294959104
[ 257.789764] bio df3840c0, biotail df3848c0, buffer (null), len
1526726656
[ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
[ 257.794921] request botched: dev mmcblk0: type=1, flags=122c8081
[ 257.794921] sector 4194304, nr/cnr 2981888/4294959104
[ 257.794921] bio df3840c0, biotail df3848c0, buffer (null), len
1526726656
This patch fixes this issue.
Reported-by: Max Filippov <[email protected]>
Signed-off-by: Namjae Jeon <[email protected]>
Signed-off-by: James Bottomley <[email protected]>
Tested-by: Max Filippov <[email protected]>
Cc: <[email protected]>
---
include/linux/blkdev.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 07aa5f6..ff636bd 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -844,7 +844,7 @@ static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
unsigned int cmd_flags)
{
if (unlikely(cmd_flags & REQ_DISCARD))
- return q->limits.max_discard_sectors;
+ return min(q->limits.max_discard_sectors, UINT_MAX >> 9);
if (unlikely(cmd_flags & REQ_WRITE_SAME))
return q->limits.max_write_same_sectors;
--
1.7.9.5
On Wed, 2013-04-24 at 22:55 +0900, Namjae Jeon wrote:
> From: James Bottomley <[email protected]>
>
> linux-v3.8-rc1 and later support for plug for blkdev_issue_discard with
> commit 0cfbcafcae8b7364b5fa96c2b26ccde7a3a296a9
> (block: add plug for blkdev_issue_discard )
>
> For example,
> 1) DISCARD rq-1 with size size 4GB
> 2) DISCARD rq-2 with size size 1GB
>
> If these 2 discard requests get merged, final request size will be 5GB.
>
> In this case, request's __data_len field may overflow as it can store
> max 4GB(unsigned int).
>
> This issue was observed while doing mkfs.f2fs on 5GB SD card:
> https://lkml.org/lkml/2013/4/1/292
>
> Info: sector size = 512
> Info: total sectors = 11370496 (in 512bytes)
> Info: zone aligned segment0 blkaddr: 512
> [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
>
> mkfs process gets stuck in D state and I see the following in the dmesg:
>
> [ 257.789733] __end_that: dev mmcblk0: type=1, flags=122c8081
> [ 257.789764] sector 4194304, nr/cnr 2981888/4294959104
> [ 257.789764] bio df3840c0, biotail df3848c0, buffer (null), len
> 1526726656
> [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
> [ 257.794921] request botched: dev mmcblk0: type=1, flags=122c8081
> [ 257.794921] sector 4194304, nr/cnr 2981888/4294959104
> [ 257.794921] bio df3840c0, biotail df3848c0, buffer (null), len
> 1526726656
>
> This patch fixes this issue.
>
> Reported-by: Max Filippov <[email protected]>
> Signed-off-by: Namjae Jeon <[email protected]>
> Signed-off-by: James Bottomley <[email protected]>
> Tested-by: Max Filippov <[email protected]>
> Cc: <[email protected]>
The two signoffs need to be reversed (they follow the chain of
transmission from the author into the kernel), but other than that, this
looks great. I assume Jens can just hand edit this one issue.
Thanks,
James
On Wed, Apr 24 2013, Namjae Jeon wrote:
> From: James Bottomley <[email protected]>
>
> linux-v3.8-rc1 and later support for plug for blkdev_issue_discard with
> commit 0cfbcafcae8b7364b5fa96c2b26ccde7a3a296a9
> (block: add plug for blkdev_issue_discard )
>
> For example,
> 1) DISCARD rq-1 with size size 4GB
> 2) DISCARD rq-2 with size size 1GB
>
> If these 2 discard requests get merged, final request size will be 5GB.
>
> In this case, request's __data_len field may overflow as it can store
> max 4GB(unsigned int).
>
> This issue was observed while doing mkfs.f2fs on 5GB SD card:
> https://lkml.org/lkml/2013/4/1/292
>
> Info: sector size = 512
> Info: total sectors = 11370496 (in 512bytes)
> Info: zone aligned segment0 blkaddr: 512
> [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
>
> mkfs process gets stuck in D state and I see the following in the dmesg:
>
> [ 257.789733] __end_that: dev mmcblk0: type=1, flags=122c8081
> [ 257.789764] sector 4194304, nr/cnr 2981888/4294959104
> [ 257.789764] bio df3840c0, biotail df3848c0, buffer (null), len
> 1526726656
> [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
> [ 257.794921] request botched: dev mmcblk0: type=1, flags=122c8081
> [ 257.794921] sector 4194304, nr/cnr 2981888/4294959104
> [ 257.794921] bio df3840c0, biotail df3848c0, buffer (null), len
> 1526726656
>
> This patch fixes this issue.
>
> Reported-by: Max Filippov <[email protected]>
> Signed-off-by: Namjae Jeon <[email protected]>
> Signed-off-by: James Bottomley <[email protected]>
> Tested-by: Max Filippov <[email protected]>
> Cc: <[email protected]>
Thanks! One minor nit - I don't think James signed off on the patch when
he sent it in. James?
--
Jens Axboe
On Wed, 2013-04-24 at 08:23 -0600, Jens Axboe wrote:
> On Wed, Apr 24 2013, Namjae Jeon wrote:
> > From: James Bottomley <[email protected]>
> >
> > linux-v3.8-rc1 and later support for plug for blkdev_issue_discard with
> > commit 0cfbcafcae8b7364b5fa96c2b26ccde7a3a296a9
> > (block: add plug for blkdev_issue_discard )
> >
> > For example,
> > 1) DISCARD rq-1 with size size 4GB
> > 2) DISCARD rq-2 with size size 1GB
> >
> > If these 2 discard requests get merged, final request size will be 5GB.
> >
> > In this case, request's __data_len field may overflow as it can store
> > max 4GB(unsigned int).
> >
> > This issue was observed while doing mkfs.f2fs on 5GB SD card:
> > https://lkml.org/lkml/2013/4/1/292
> >
> > Info: sector size = 512
> > Info: total sectors = 11370496 (in 512bytes)
> > Info: zone aligned segment0 blkaddr: 512
> > [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
> >
> > mkfs process gets stuck in D state and I see the following in the dmesg:
> >
> > [ 257.789733] __end_that: dev mmcblk0: type=1, flags=122c8081
> > [ 257.789764] sector 4194304, nr/cnr 2981888/4294959104
> > [ 257.789764] bio df3840c0, biotail df3848c0, buffer (null), len
> > 1526726656
> > [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
> > [ 257.794921] request botched: dev mmcblk0: type=1, flags=122c8081
> > [ 257.794921] sector 4194304, nr/cnr 2981888/4294959104
> > [ 257.794921] bio df3840c0, biotail df3848c0, buffer (null), len
> > 1526726656
> >
> > This patch fixes this issue.
> >
> > Reported-by: Max Filippov <[email protected]>
> > Signed-off-by: Namjae Jeon <[email protected]>
> > Signed-off-by: James Bottomley <[email protected]>
> > Tested-by: Max Filippov <[email protected]>
> > Cc: <[email protected]>
>
> Thanks! One minor nit - I don't think James signed off on the patch when
> he sent it in. James?
I didn't, but silence is really acquiescence in this game. However, now
you have my positive confirmation that I'm good with the signoff.
James
On Wed, Apr 24 2013, James Bottomley wrote:
> On Wed, 2013-04-24 at 22:55 +0900, Namjae Jeon wrote:
> > From: James Bottomley <[email protected]>
> >
> > linux-v3.8-rc1 and later support for plug for blkdev_issue_discard with
> > commit 0cfbcafcae8b7364b5fa96c2b26ccde7a3a296a9
> > (block: add plug for blkdev_issue_discard )
> >
> > For example,
> > 1) DISCARD rq-1 with size size 4GB
> > 2) DISCARD rq-2 with size size 1GB
> >
> > If these 2 discard requests get merged, final request size will be 5GB.
> >
> > In this case, request's __data_len field may overflow as it can store
> > max 4GB(unsigned int).
> >
> > This issue was observed while doing mkfs.f2fs on 5GB SD card:
> > https://lkml.org/lkml/2013/4/1/292
> >
> > Info: sector size = 512
> > Info: total sectors = 11370496 (in 512bytes)
> > Info: zone aligned segment0 blkaddr: 512
> > [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
> >
> > mkfs process gets stuck in D state and I see the following in the dmesg:
> >
> > [ 257.789733] __end_that: dev mmcblk0: type=1, flags=122c8081
> > [ 257.789764] sector 4194304, nr/cnr 2981888/4294959104
> > [ 257.789764] bio df3840c0, biotail df3848c0, buffer (null), len
> > 1526726656
> > [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
> > [ 257.794921] request botched: dev mmcblk0: type=1, flags=122c8081
> > [ 257.794921] sector 4194304, nr/cnr 2981888/4294959104
> > [ 257.794921] bio df3840c0, biotail df3848c0, buffer (null), len
> > 1526726656
> >
> > This patch fixes this issue.
> >
> > Reported-by: Max Filippov <[email protected]>
> > Signed-off-by: Namjae Jeon <[email protected]>
> > Signed-off-by: James Bottomley <[email protected]>
> > Tested-by: Max Filippov <[email protected]>
> > Cc: <[email protected]>
>
> The two signoffs need to be reversed (they follow the chain of
> transmission from the author into the kernel), but other than that, this
> looks great. I assume Jens can just hand edit this one issue.
Yeah, I'll just hand edit thank. Thanks all.
--
Jens Axboe