nvmet: add error log support for file backend

This patch adds support for the file backend to populate the
error log entries. Here we map the errno to the NVMe status codes.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/core.c

@@ -45,6 +45,44 @@ u32 nvmet_ana_group_enabled[NVMET_MAX_ANAGRPS + 1];
 u64 nvmet_ana_chgcnt;
 DECLARE_RWSEM(nvmet_ana_sem);
 
+inline u16 errno_to_nvme_status(struct nvmet_req *req, int errno)
+{
+	u16 status;
+
+	switch (errno) {
+	case -ENOSPC:
+		req->error_loc = offsetof(struct nvme_rw_command, length);
+		status = NVME_SC_CAP_EXCEEDED | NVME_SC_DNR;
+		break;
+	case -EREMOTEIO:
+		req->error_loc = offsetof(struct nvme_rw_command, slba);
+		status = NVME_SC_LBA_RANGE | NVME_SC_DNR;
+		break;
+	case -EOPNOTSUPP:
+		req->error_loc = offsetof(struct nvme_common_command, opcode);
+		switch (req->cmd->common.opcode) {
+		case nvme_cmd_dsm:
+		case nvme_cmd_write_zeroes:
+			status = NVME_SC_ONCS_NOT_SUPPORTED | NVME_SC_DNR;
+			break;
+		default:
+			status = NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
+		}
+		break;
+	case -ENODATA:
+		req->error_loc = offsetof(struct nvme_rw_command, nsid);
+		status = NVME_SC_ACCESS_DENIED;
+		break;
+	case -EIO:
+		/* FALLTHRU */
+	default:
+		req->error_loc = offsetof(struct nvme_common_command, opcode);
+		status = NVME_SC_INTERNAL | NVME_SC_DNR;
+	}
+
+	return status;
+}
+
 static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
 		const char *subsysnqn);
 

drivers/nvme/target/io-cmd-file.c

@@ -112,6 +112,7 @@ static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
 static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2)
 {
 	struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb);
+	u16 status = NVME_SC_SUCCESS;
 
 	if (req->f.bvec != req->inline_bvec) {
 		if (likely(req->f.mpool_alloc == false))
@@ -120,8 +121,9 @@ static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2)
 			mempool_free(req->f.bvec, req->ns->bvec_pool);
 	}
 
-	nvmet_req_complete(req, ret != req->data_len ?
-			NVME_SC_INTERNAL | NVME_SC_DNR : 0);
+	if (unlikely(ret != req->data_len))
+		status = errno_to_nvme_status(req, ret);
+	nvmet_req_complete(req, status);
 }
 
 static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags)
@@ -140,7 +142,7 @@ static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags)
 
 	pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
 	if (unlikely(pos + req->data_len > req->ns->size)) {
-		nvmet_req_complete(req, NVME_SC_LBA_RANGE | NVME_SC_DNR);
+		nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
 		return true;
 	}
 
@@ -254,9 +256,7 @@ static void nvmet_file_execute_rw(struct nvmet_req *req)
 
 u16 nvmet_file_flush(struct nvmet_req *req)
 {
-	if (vfs_fsync(req->ns->file, 1) < 0)
-		return NVME_SC_INTERNAL | NVME_SC_DNR;
-	return 0;
+	return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
 }
 
 static void nvmet_file_flush_work(struct work_struct *w)
@@ -277,30 +277,34 @@ static void nvmet_file_execute_discard(struct nvmet_req *req)
 	int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 	struct nvme_dsm_range range;
 	loff_t offset, len;
-	u16 ret;
+	u16 status = 0;
+	int ret;
 	int i;
 
 	for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
-		ret = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
+		status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 					sizeof(range));
-		if (ret)
+		if (status)
 			break;
 
 		offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
 		len = le32_to_cpu(range.nlb);
 		len <<= req->ns->blksize_shift;
 		if (offset + len > req->ns->size) {
-			ret = NVME_SC_LBA_RANGE | NVME_SC_DNR;
+			req->error_slba = le64_to_cpu(range.slba);
+			status = errno_to_nvme_status(req, -ENOSPC);
 			break;
 		}
 
-		if (vfs_fallocate(req->ns->file, mode, offset, len)) {
-			ret = NVME_SC_INTERNAL | NVME_SC_DNR;
+		ret = vfs_fallocate(req->ns->file, mode, offset, len);
+		if (ret) {
+			req->error_slba = le64_to_cpu(range.slba);
+			status = errno_to_nvme_status(req, ret);
 			break;
 		}
 	}
 
-	nvmet_req_complete(req, ret);
+	nvmet_req_complete(req, status);
 }
 
 static void nvmet_file_dsm_work(struct work_struct *w)
@@ -340,12 +344,12 @@ static void nvmet_file_write_zeroes_work(struct work_struct *w)
 			req->ns->blksize_shift);
 
 	if (unlikely(offset + len > req->ns->size)) {
-		nvmet_req_complete(req, NVME_SC_LBA_RANGE | NVME_SC_DNR);
+		nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
 		return;
 	}
 
 	ret = vfs_fallocate(req->ns->file, mode, offset, len);
-	nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
+	nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0);
 }
 
 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
@@ -380,6 +384,7 @@ u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
 	default:
 		pr_err("unhandled cmd for file ns %d on qid %d\n",
 				cmd->common.opcode, req->sq->qid);
+		req->error_loc = offsetof(struct nvme_common_command, opcode);
 		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 	}
 }

drivers/nvme/target/nvmet.h

@@ -494,4 +494,6 @@ static inline u32 nvmet_rw_len(struct nvmet_req *req)
 	return ((u32)le16_to_cpu(req->cmd->rw.length) + 1) <<
 			req->ns->blksize_shift;
 }
+
+u16 errno_to_nvme_status(struct nvmet_req *req, int errno);
 #endif /* _NVMET_H */