nvmet: fix discover log page when offsets are used

[ Upstream commit d808b7f759b50acf0784ce6230ffa63e12ef465d ]

The nvme target hadn't been taking the Get Log Page offset parameter
into consideration, and so has been returning corrupted log pages when
offsets are used. Since many tools, including nvme-cli, split the log
request to 4k, we've been breaking discovery log responses when more
than 3 subsystems exist.

Fix the returned data by internally generating the entire discovery
log page and copying only the requested bytes into the user buffer. The
command log page offset type has been modified to a native __le64 to
make it easier to extract the value from a command.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Tested-by: Minwoo Im <minwoo.im@samsung.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 11baeb14c38810c715060d6bb82be6aeaffe3f9e..8fdae510c5ac0adc1fea204b2d0bca9495ef5f13 100644 (file)
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -32,6 +32,11 @@ u32 nvmet_get_log_page_len(struct nvme_command *cmd)
        return len;
 }
 
+u64 nvmet_get_log_page_offset(struct nvme_command *cmd)
+{
+       return le64_to_cpu(cmd->get_log_page.lpo);
+}
+
 static void nvmet_execute_get_log_page_noop(struct nvmet_req *req)
 {
        nvmet_req_complete(req, nvmet_zero_sgl(req, 0, req->data_len));

diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c
index d2cb71a0b419d6ac1cc920dbab2ba1b576be86e1..389c1a90197d95a9c7a1f25e9c288f724d23e499 100644 (file)
--- a/drivers/nvme/target/discovery.c
+++ b/drivers/nvme/target/discovery.c
@@ -139,54 +139,76 @@ static void nvmet_set_disc_traddr(struct nvmet_req *req, struct nvmet_port *port
                memcpy(traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
 }
 
+static size_t discovery_log_entries(struct nvmet_req *req)
+{
+       struct nvmet_ctrl *ctrl = req->sq->ctrl;
+       struct nvmet_subsys_link *p;
+       struct nvmet_port *r;
+       size_t entries = 0;
+
+       list_for_each_entry(p, &req->port->subsystems, entry) {
+               if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
+                       continue;
+               entries++;
+       }
+       list_for_each_entry(r, &req->port->referrals, entry)
+               entries++;
+       return entries;
+}
+
 static void nvmet_execute_get_disc_log_page(struct nvmet_req *req)
 {
        const int entry_size = sizeof(struct nvmf_disc_rsp_page_entry);
        struct nvmet_ctrl *ctrl = req->sq->ctrl;
        struct nvmf_disc_rsp_page_hdr *hdr;
+       u64 offset = nvmet_get_log_page_offset(req->cmd);
        size_t data_len = nvmet_get_log_page_len(req->cmd);
-       size_t alloc_len = max(data_len, sizeof(*hdr));
-       int residual_len = data_len - sizeof(*hdr);
+       size_t alloc_len;
        struct nvmet_subsys_link *p;
        struct nvmet_port *r;
        u32 numrec = 0;
        u16 status = 0;
+       void *buffer;
+
+       /* Spec requires dword aligned offsets */
+       if (offset & 0x3) {
+               status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+               goto out;
+       }
 
        /*
         * Make sure we're passing at least a buffer of response header size.
         * If host provided data len is less than the header size, only the
         * number of bytes requested by host will be sent to host.
         */
-       hdr = kzalloc(alloc_len, GFP_KERNEL);
-       if (!hdr) {
+       down_read(&nvmet_config_sem);
+       alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);
+       buffer = kzalloc(alloc_len, GFP_KERNEL);
+       if (!buffer) {
+               up_read(&nvmet_config_sem);
                status = NVME_SC_INTERNAL;
                goto out;
        }
 
-       down_read(&nvmet_config_sem);
+       hdr = buffer;
        list_for_each_entry(p, &req->port->subsystems, entry) {
+               char traddr[NVMF_TRADDR_SIZE];
+
                if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
                        continue;
-               if (residual_len >= entry_size) {
-                       char traddr[NVMF_TRADDR_SIZE];
-
-                       nvmet_set_disc_traddr(req, req->port, traddr);
-                       nvmet_format_discovery_entry(hdr, req->port,
-                                       p->subsys->subsysnqn, traddr,
-                                       NVME_NQN_NVME, numrec);
-                       residual_len -= entry_size;
-               }
+
+               nvmet_set_disc_traddr(req, req->port, traddr);
+               nvmet_format_discovery_entry(hdr, req->port,
+                               p->subsys->subsysnqn, traddr,
+                               NVME_NQN_NVME, numrec);
                numrec++;
        }
 
        list_for_each_entry(r, &req->port->referrals, entry) {
-               if (residual_len >= entry_size) {
-                       nvmet_format_discovery_entry(hdr, r,
-                                       NVME_DISC_SUBSYS_NAME,
-                                       r->disc_addr.traddr,
-                                       NVME_NQN_DISC, numrec);
-                       residual_len -= entry_size;
-               }
+               nvmet_format_discovery_entry(hdr, r,
+                               NVME_DISC_SUBSYS_NAME,
+                               r->disc_addr.traddr,
+                               NVME_NQN_DISC, numrec);
                numrec++;
        }
 
@@ -198,8 +220,8 @@ static void nvmet_execute_get_disc_log_page(struct nvmet_req *req)
 
        up_read(&nvmet_config_sem);
 
-       status = nvmet_copy_to_sgl(req, 0, hdr, data_len);
-       kfree(hdr);
+       status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);
+       kfree(buffer);
 out:
        nvmet_req_complete(req, status);
 }

diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 3e4719fdba8547f25126fecc4bea39ed0d0b1bf5..d253c45c1aa6e5864eb063da9fc67b7b6c7c7e7d 100644 (file)
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -436,6 +436,7 @@ u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf,
 u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len);
 
 u32 nvmet_get_log_page_len(struct nvme_command *cmd);
+u64 nvmet_get_log_page_offset(struct nvme_command *cmd);
 
 extern struct list_head *nvmet_ports;
 void nvmet_port_disc_changed(struct nvmet_port *port,

diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index bbcc83886899ceb8e3dd0a0c63ede06a9a81c29c..7ba0368f16e6ec38dc9cfa3c601ed0cc3f8aa5ee 100644 (file)
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -975,8 +975,13 @@ struct nvme_get_log_page_command {
        __le16                  numdl;
        __le16                  numdu;
        __u16                   rsvd11;
-       __le32                  lpol;
-       __le32                  lpou;
+       union {
+               struct {
+                       __le32 lpol;
+                       __le32 lpou;
+               };
+               __le64 lpo;
+       };
        __u32                   rsvd14[2];
 };