nvmet: fix discover log page when offsets are used

[thirdparty/kernel/stable.git] / drivers / nvme / target / discovery.c

diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c
index c872b47a88f31722b358e219c403f2c2cb765988..33ed95e72d6b19598f76df0c50f6fccfdaec37bd 100644 (file)
--- a/drivers/nvme/target/discovery.c
+++ b/drivers/nvme/target/discovery.c
@@ -131,54 +131,76 @@ 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++;
        }
 
@@ -190,8 +212,8 @@ 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);
 }