nvmet: add ns write protect support

This patch implements the Namespace Write Protect feature described in
"NVMe TP 4005a Namespace Write Protect". In this version, we implement
No Write Protect and Write Protect states for target ns which can be
toggled by set-features commands from the host side.

For write-protect state transition, we need to flush the ns specified
as a part of command so we also add helpers for carrying out synchronous
flush operations.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
[hch: fixed an incorrect endianess conversion, minor cleanups]
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Chaitanya Kulkarni
2018-08-07 23:01:07 -07:00
committed by Christoph Hellwig
parent 1293477f4f
commit dedf0be544
5 changed files with 114 additions and 5 deletions

View File

@@ -372,6 +372,8 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
id->psd[0].entry_lat = cpu_to_le32(0x10);
id->psd[0].exit_lat = cpu_to_le32(0x4);
id->nwpc = 1 << 0; /* write protect and no write protect */
status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
kfree(id);
@@ -433,6 +435,8 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
id->lbaf[0].ds = ns->blksize_shift;
if (ns->readonly)
id->nsattr |= (1 << 0);
nvmet_put_namespace(ns);
done:
status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
@@ -545,6 +549,52 @@ static void nvmet_execute_abort(struct nvmet_req *req)
nvmet_req_complete(req, 0);
}
static u16 nvmet_write_protect_flush_sync(struct nvmet_req *req)
{
u16 status;
if (req->ns->file)
status = nvmet_file_flush(req);
else
status = nvmet_bdev_flush(req);
if (status)
pr_err("write protect flush failed nsid: %u\n", req->ns->nsid);
return status;
}
static u16 nvmet_set_feat_write_protect(struct nvmet_req *req)
{
u32 write_protect = le32_to_cpu(req->cmd->common.cdw10[1]);
struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
u16 status = NVME_SC_FEATURE_NOT_CHANGEABLE;
req->ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->rw.nsid);
if (unlikely(!req->ns))
return status;
mutex_lock(&subsys->lock);
switch (write_protect) {
case NVME_NS_WRITE_PROTECT:
req->ns->readonly = true;
status = nvmet_write_protect_flush_sync(req);
if (status)
req->ns->readonly = false;
break;
case NVME_NS_NO_WRITE_PROTECT:
req->ns->readonly = false;
status = 0;
break;
default:
break;
}
if (!status)
nvmet_ns_changed(subsys, req->ns->nsid);
mutex_unlock(&subsys->lock);
return status;
}
static void nvmet_execute_set_features(struct nvmet_req *req)
{
struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
@@ -575,6 +625,9 @@ static void nvmet_execute_set_features(struct nvmet_req *req)
case NVME_FEAT_HOST_ID:
status = NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
break;
case NVME_FEAT_WRITE_PROTECT:
status = nvmet_set_feat_write_protect(req);
break;
default:
status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
break;
@@ -583,6 +636,26 @@ static void nvmet_execute_set_features(struct nvmet_req *req)
nvmet_req_complete(req, status);
}
static u16 nvmet_get_feat_write_protect(struct nvmet_req *req)
{
struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
u32 result;
req->ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->common.nsid);
if (!req->ns)
return NVME_SC_INVALID_NS | NVME_SC_DNR;
mutex_lock(&subsys->lock);
if (req->ns->readonly == true)
result = NVME_NS_WRITE_PROTECT;
else
result = NVME_NS_NO_WRITE_PROTECT;
nvmet_set_result(req, result);
mutex_unlock(&subsys->lock);
return 0;
}
static void nvmet_execute_get_features(struct nvmet_req *req)
{
struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
@@ -634,6 +707,9 @@ static void nvmet_execute_get_features(struct nvmet_req *req)
status = nvmet_copy_to_sgl(req, 0, &req->sq->ctrl->hostid,
sizeof(req->sq->ctrl->hostid));
break;
case NVME_FEAT_WRITE_PROTECT:
status = nvmet_get_feat_write_protect(req);
break;
default:
status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
break;