* [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES
@ 2020-10-16 22:19 Logan Gunthorpe
2020-10-16 22:19 ` [PATCH v2 2/2] nvmet-passthru: Cleanup nvmet_passthru_map_sg() Logan Gunthorpe
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Logan Gunthorpe @ 2020-10-16 22:19 UTC (permalink / raw)
To: linux-nvme
Cc: Logan Gunthorpe, Christoph Hellwig, Chaitanya Kulkarni, Sagi Grimberg
nvmet_passthru_map_sg() only supports mapping a single BIO, not a chain
so the effective maximum transfer should also be limitted by BIO_MAX_PAGES
(presently this works out to 1MB).
For PCI passthru devices the max_sectors would typically be more limitting
than BIO_MAX_PAGES, but this may not be true for all passthru devices.
Fixes: c1fef73f793b ("nvmet: add passthru code to process commands")
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
drivers/nvme/target/passthru.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
index dacfa7435d0b..1ab88df3310f 100644
--- a/drivers/nvme/target/passthru.c
+++ b/drivers/nvme/target/passthru.c
@@ -26,7 +26,7 @@ static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
struct nvme_ctrl *pctrl = ctrl->subsys->passthru_ctrl;
u16 status = NVME_SC_SUCCESS;
struct nvme_id_ctrl *id;
- u32 max_hw_sectors;
+ int max_hw_sectors;
int page_shift;
id = kzalloc(sizeof(*id), GFP_KERNEL);
@@ -48,6 +48,13 @@ static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
max_hw_sectors = min_not_zero(pctrl->max_segments << (PAGE_SHIFT - 9),
pctrl->max_hw_sectors);
+ /*
+ * nvmet_passthru_map_sg is limitted to using a single bio so limit
+ * the mdts based on BIO_MAX_PAGES as well
+ */
+ max_hw_sectors = min_not_zero(BIO_MAX_PAGES << (PAGE_SHIFT - 9),
+ max_hw_sectors);
+
page_shift = NVME_CAP_MPSMIN(ctrl->cap) + 12;
id->mdts = ilog2(max_hw_sectors) + 9 - page_shift;
base-commit: bbf5c979011a099af5dc76498918ed7df445635b
--
2.20.1
_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 2/2] nvmet-passthru: Cleanup nvmet_passthru_map_sg()
2020-10-16 22:19 [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES Logan Gunthorpe
@ 2020-10-16 22:19 ` Logan Gunthorpe
2020-10-19 11:20 ` [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES Max Gurtovoy
2020-10-22 13:29 ` Christoph Hellwig
2 siblings, 0 replies; 6+ messages in thread
From: Logan Gunthorpe @ 2020-10-16 22:19 UTC (permalink / raw)
To: linux-nvme
Cc: Christoph Hellwig, Logan Gunthorpe, Sagi Grimberg,
Chaitanya Kulkarni, Douglas Gilbert
Clean up some confusing elements of nvmet_passthru_map_sg() by returning
early if the request is greater than the maximum bio size. This allows
us to drop the sg_cnt variable.
This should not result in any functional change but makes the code
clearer and more understandable. The original code allocated a truncated
bio then would return EINVAL when bio_add_pc_page() filled that bio. The
new code just returns EINVAL early if this would happen.
Fixes: c1fef73f793b ("nvmet: add passthru code to process commands")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Suggested-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
drivers/nvme/target/passthru.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
index 1ab88df3310f..8ea9b173f285 100644
--- a/drivers/nvme/target/passthru.c
+++ b/drivers/nvme/target/passthru.c
@@ -187,18 +187,20 @@ static void nvmet_passthru_req_done(struct request *rq,
static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq)
{
- int sg_cnt = req->sg_cnt;
struct scatterlist *sg;
int op_flags = 0;
struct bio *bio;
int i, ret;
+ if (req->sg_cnt > BIO_MAX_PAGES)
+ return -EINVAL;
+
if (req->cmd->common.opcode == nvme_cmd_flush)
op_flags = REQ_FUA;
else if (nvme_is_write(req->cmd))
op_flags = REQ_SYNC | REQ_IDLE;
- bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
+ bio = bio_alloc(GFP_KERNEL, req->sg_cnt);
bio->bi_end_io = bio_put;
bio->bi_opf = req_op(rq) | op_flags;
@@ -208,7 +210,6 @@ static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq)
bio_put(bio);
return -EINVAL;
}
- sg_cnt--;
}
ret = blk_rq_append_bio(rq, &bio);
--
2.20.1
_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES
2020-10-16 22:19 [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES Logan Gunthorpe
2020-10-16 22:19 ` [PATCH v2 2/2] nvmet-passthru: Cleanup nvmet_passthru_map_sg() Logan Gunthorpe
@ 2020-10-19 11:20 ` Max Gurtovoy
2020-10-19 15:40 ` Logan Gunthorpe
2020-10-22 13:29 ` Christoph Hellwig
2 siblings, 1 reply; 6+ messages in thread
From: Max Gurtovoy @ 2020-10-19 11:20 UTC (permalink / raw)
To: Logan Gunthorpe, linux-nvme
Cc: Christoph Hellwig, Chaitanya Kulkarni, Sagi Grimberg
On 10/17/2020 1:19 AM, Logan Gunthorpe wrote:
> nvmet_passthru_map_sg() only supports mapping a single BIO, not a chain
> so the effective maximum transfer should also be limitted by BIO_MAX_PAGES
> (presently this works out to 1MB).
>
> For PCI passthru devices the max_sectors would typically be more limitting
> than BIO_MAX_PAGES, but this may not be true for all passthru devices.
>
> Fixes: c1fef73f793b ("nvmet: add passthru code to process commands")
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Sagi Grimberg <sagi@grimberg.me>
> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> ---
> drivers/nvme/target/passthru.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
> index dacfa7435d0b..1ab88df3310f 100644
> --- a/drivers/nvme/target/passthru.c
> +++ b/drivers/nvme/target/passthru.c
> @@ -26,7 +26,7 @@ static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
> struct nvme_ctrl *pctrl = ctrl->subsys->passthru_ctrl;
> u16 status = NVME_SC_SUCCESS;
> struct nvme_id_ctrl *id;
> - u32 max_hw_sectors;
> + int max_hw_sectors;
> int page_shift;
>
> id = kzalloc(sizeof(*id), GFP_KERNEL);
> @@ -48,6 +48,13 @@ static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
> max_hw_sectors = min_not_zero(pctrl->max_segments << (PAGE_SHIFT - 9),
> pctrl->max_hw_sectors);
>
> + /*
> + * nvmet_passthru_map_sg is limitted to using a single bio so limit
> + * the mdts based on BIO_MAX_PAGES as well
> + */
> + max_hw_sectors = min_not_zero(BIO_MAX_PAGES << (PAGE_SHIFT - 9),
> + max_hw_sectors);
can 9 be replaced with SECTOR_SHIFT ?
> +
> page_shift = NVME_CAP_MPSMIN(ctrl->cap) + 12;
>
> id->mdts = ilog2(max_hw_sectors) + 9 - page_shift;
>
> base-commit: bbf5c979011a099af5dc76498918ed7df445635b
_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES
2020-10-19 11:20 ` [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES Max Gurtovoy
@ 2020-10-19 15:40 ` Logan Gunthorpe
[not found] ` <BYAPR04MB4965B1360F5F6A1D13FF1DD0861F0@BYAPR04MB4965.namprd04.prod.outlook.com>
0 siblings, 1 reply; 6+ messages in thread
From: Logan Gunthorpe @ 2020-10-19 15:40 UTC (permalink / raw)
To: Max Gurtovoy, linux-nvme
Cc: Christoph Hellwig, Chaitanya Kulkarni, Sagi Grimberg
On 2020-10-19 5:20 a.m., Max Gurtovoy wrote:
>
> On 10/17/2020 1:19 AM, Logan Gunthorpe wrote:
>> nvmet_passthru_map_sg() only supports mapping a single BIO, not a chain
>> so the effective maximum transfer should also be limitted by BIO_MAX_PAGES
>> (presently this works out to 1MB).
>>
>> For PCI passthru devices the max_sectors would typically be more limitting
>> than BIO_MAX_PAGES, but this may not be true for all passthru devices.
>>
>> Fixes: c1fef73f793b ("nvmet: add passthru code to process commands")
>> Suggested-by: Christoph Hellwig <hch@lst.de>
>> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
>> Cc: Christoph Hellwig <hch@lst.de>
>> Cc: Sagi Grimberg <sagi@grimberg.me>
>> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
>> ---
>> drivers/nvme/target/passthru.c | 9 ++++++++-
>> 1 file changed, 8 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
>> index dacfa7435d0b..1ab88df3310f 100644
>> --- a/drivers/nvme/target/passthru.c
>> +++ b/drivers/nvme/target/passthru.c
>> @@ -26,7 +26,7 @@ static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
>> struct nvme_ctrl *pctrl = ctrl->subsys->passthru_ctrl;
>> u16 status = NVME_SC_SUCCESS;
>> struct nvme_id_ctrl *id;
>> - u32 max_hw_sectors;
>> + int max_hw_sectors;
>> int page_shift;
>>
>> id = kzalloc(sizeof(*id), GFP_KERNEL);
>> @@ -48,6 +48,13 @@ static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
>> max_hw_sectors = min_not_zero(pctrl->max_segments << (PAGE_SHIFT - 9),
>> pctrl->max_hw_sectors);
>>
>> + /*
>> + * nvmet_passthru_map_sg is limitted to using a single bio so limit
>> + * the mdts based on BIO_MAX_PAGES as well
>> + */
>> + max_hw_sectors = min_not_zero(BIO_MAX_PAGES << (PAGE_SHIFT - 9),
>> + max_hw_sectors);
>
> can 9 be replaced with SECTOR_SHIFT ?
Oh, yes, that does sound better. Thanks.
Logan
_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES
[not found] ` <BYAPR04MB4965B1360F5F6A1D13FF1DD0861F0@BYAPR04MB4965.namprd04.prod.outlook.com>
@ 2020-10-20 2:05 ` Logan Gunthorpe
0 siblings, 0 replies; 6+ messages in thread
From: Logan Gunthorpe @ 2020-10-20 2:05 UTC (permalink / raw)
To: Chaitanya Kulkarni, Max Gurtovoy, linux-nvme
Cc: Christoph Hellwig, Sagi Grimberg
On 2020-10-19 8:03 p.m., Chaitanya Kulkarni wrote:
> On 10/19/20 08:40, Logan Gunthorpe wrote:
>>>> + max_hw_sectors = min_not_zero(BIO_MAX_PAGES << (PAGE_SHIFT - 9),
>>>> + max_hw_sectors);
>>> can 9 be replaced with SECTOR_SHIFT ?
>> Oh, yes, that does sound better. Thanks.
>>
>> Logan
>>
>>
> Although it is a good suggestion we are not using the SECTOR_SIZE in
>
> the target code, I don't think we should change that for passthru. Also,
>
> I remember that on the block layer mailing list SECTOR_SIZE macro been
>
> discouraged over use of 9.
Well in that case v2 or v3 can be merged depending on maintainer preference.
Logan
_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES
2020-10-16 22:19 [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES Logan Gunthorpe
2020-10-16 22:19 ` [PATCH v2 2/2] nvmet-passthru: Cleanup nvmet_passthru_map_sg() Logan Gunthorpe
2020-10-19 11:20 ` [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES Max Gurtovoy
@ 2020-10-22 13:29 ` Christoph Hellwig
2 siblings, 0 replies; 6+ messages in thread
From: Christoph Hellwig @ 2020-10-22 13:29 UTC (permalink / raw)
To: Logan Gunthorpe
Cc: Chaitanya Kulkarni, Christoph Hellwig, linux-nvme, Sagi Grimberg
Thanks,
applied 1 and 2 to nvme-5.10.
_______________________________________________
Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-10-22 13:30 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-16 22:19 [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES Logan Gunthorpe
2020-10-16 22:19 ` [PATCH v2 2/2] nvmet-passthru: Cleanup nvmet_passthru_map_sg() Logan Gunthorpe
2020-10-19 11:20 ` [PATCH v2 1/2] nvmet-passthru: Limit mdts by BIO_MAX_PAGES Max Gurtovoy
2020-10-19 15:40 ` Logan Gunthorpe
[not found] ` <BYAPR04MB4965B1360F5F6A1D13FF1DD0861F0@BYAPR04MB4965.namprd04.prod.outlook.com>
2020-10-20 2:05 ` Logan Gunthorpe
2020-10-22 13:29 ` Christoph Hellwig
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).