lkml.org 
[lkml]   [2017]   [Apr]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH] nvmet: convert from kmap to nvmet_copy_from_sgl
This is safer as it doesn't rely on the data being stored in
a single page in an sgl.

It also aids our effort to start phasing out users of sg_page. See [1].

For this we kmalloc some memory, copy to it and free at the end. Note:
we can't allocate this memory on the stack as the kbuild test robot
reports some frame size overflows on i386.

[1] https://lwn.net/Articles/720053/

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
---
drivers/nvme/target/fabrics-cmd.c | 32 +++++++++++++++++++++++++-------
1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/drivers/nvme/target/fabrics-cmd.c b/drivers/nvme/target/fabrics-cmd.c
index 8bd022af..2e0ab10 100644
--- a/drivers/nvme/target/fabrics-cmd.c
+++ b/drivers/nvme/target/fabrics-cmd.c
@@ -122,7 +122,15 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
struct nvmet_ctrl *ctrl = NULL;
u16 status = 0;

- d = kmap(sg_page(req->sg)) + req->sg->offset;
+ d = kmalloc(sizeof(*d), GFP_KERNEL);
+ if (!d) {
+ status = NVME_SC_INTERNAL;
+ goto complete;
+ }
+
+ status = nvmet_copy_from_sgl(req, 0, d, sizeof(*d));
+ if (status)
+ goto out;

/* zero out initial completion result, assign values as needed */
req->rsp->result.u32 = 0;
@@ -143,7 +151,7 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
}

status = nvmet_alloc_ctrl(d->subsysnqn, d->hostnqn, req,
- le32_to_cpu(c->kato), &ctrl);
+ le32_to_cpu(c->kato), &ctrl);
if (status)
goto out;

@@ -158,7 +166,8 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
req->rsp->result.u16 = cpu_to_le16(ctrl->cntlid);

out:
- kunmap(sg_page(req->sg));
+ kfree(d);
+complete:
nvmet_req_complete(req, status);
}

@@ -170,7 +179,15 @@ static void nvmet_execute_io_connect(struct nvmet_req *req)
u16 qid = le16_to_cpu(c->qid);
u16 status = 0;

- d = kmap(sg_page(req->sg)) + req->sg->offset;
+ d = kmalloc(sizeof(*d), GFP_KERNEL);
+ if (!d) {
+ status = NVME_SC_INTERNAL;
+ goto complete;
+ }
+
+ status = nvmet_copy_from_sgl(req, 0, d, sizeof(*d));
+ if (status)
+ goto out;

/* zero out initial completion result, assign values as needed */
req->rsp->result.u32 = 0;
@@ -183,8 +200,8 @@ static void nvmet_execute_io_connect(struct nvmet_req *req)
}

status = nvmet_ctrl_find_get(d->subsysnqn, d->hostnqn,
- le16_to_cpu(d->cntlid),
- req, &ctrl);
+ le16_to_cpu(d->cntlid),
+ req, &ctrl);
if (status)
goto out;

@@ -205,7 +222,8 @@ static void nvmet_execute_io_connect(struct nvmet_req *req)
pr_info("adding queue %d to ctrl %d.\n", qid, ctrl->cntlid);

out:
- kunmap(sg_page(req->sg));
+ kfree(d);
+complete:
nvmet_req_complete(req, status);
return;

--
2.1.4
\
 
 \ /
  Last update: 2017-04-19 01:33    [W:0.123 / U:6.288 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site