1 files changed, 382 insertions, 0 deletions

diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
new file mode 100644
index 000000000..2d068439b
--- /dev/null
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVMe Over Fabrics Target File I/O commands implementation.
+ * Copyright (c) 2017-2018 Western Digital Corporation or its
+ * affiliates.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/uio.h>
+#include <linux/falloc.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include "nvmet.h"
+
+#define NVMET_MIN_MPOOL_OBJ		16
+
+void nvmet_file_ns_revalidate(struct nvmet_ns *ns)
+{
+	ns->size = i_size_read(ns->file->f_mapping->host);
+}
+
+void nvmet_file_ns_disable(struct nvmet_ns *ns)
+{
+	if (ns->file) {
+		if (ns->buffered_io)
+			flush_workqueue(buffered_io_wq);
+		mempool_destroy(ns->bvec_pool);
+		ns->bvec_pool = NULL;
+		fput(ns->file);
+		ns->file = NULL;
+	}
+}
+
+int nvmet_file_ns_enable(struct nvmet_ns *ns)
+{
+	int flags = O_RDWR | O_LARGEFILE;
+	int ret = 0;
+
+	if (!ns->buffered_io)
+		flags |= O_DIRECT;
+
+	ns->file = filp_open(ns->device_path, flags, 0);
+	if (IS_ERR(ns->file)) {
+		ret = PTR_ERR(ns->file);
+		pr_err("failed to open file %s: (%d)\n",
+			ns->device_path, ret);
+		ns->file = NULL;
+		return ret;
+	}
+
+	nvmet_file_ns_revalidate(ns);
+
+	/*
+	 * i_blkbits can be greater than the universally accepted upper bound,
+	 * so make sure we export a sane namespace lba_shift.
+	 */
+	ns->blksize_shift = min_t(u8,
+			file_inode(ns->file)->i_blkbits, 12);
+
+	ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab,
+			mempool_free_slab, nvmet_bvec_cache);
+
+	if (!ns->bvec_pool) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	return ret;
+err:
+	fput(ns->file);
+	ns->file = NULL;
+	ns->size = 0;
+	ns->blksize_shift = 0;
+	return ret;
+}
+
+static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
+		unsigned long nr_segs, size_t count, int ki_flags)
+{
+	struct kiocb *iocb = &req->f.iocb;
+	ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter);
+	struct iov_iter iter;
+	int rw;
+
+	if (req->cmd->rw.opcode == nvme_cmd_write) {
+		if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
+			ki_flags |= IOCB_DSYNC;
+		call_iter = req->ns->file->f_op->write_iter;
+		rw = ITER_SOURCE;
+	} else {
+		call_iter = req->ns->file->f_op->read_iter;
+		rw = ITER_DEST;
+	}
+
+	iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count);
+
+	iocb->ki_pos = pos;
+	iocb->ki_filp = req->ns->file;
+	iocb->ki_flags = ki_flags | iocb->ki_filp->f_iocb_flags;
+
+	return call_iter(iocb, &iter);
+}
+
+static void nvmet_file_io_done(struct kiocb *iocb, long ret)
+{
+	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))
+			kfree(req->f.bvec);
+		else
+			mempool_free(req->f.bvec, req->ns->bvec_pool);
+	}
+
+	if (unlikely(ret != req->transfer_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)
+{
+	ssize_t nr_bvec = req->sg_cnt;
+	unsigned long bv_cnt = 0;
+	bool is_sync = false;
+	size_t len = 0, total_len = 0;
+	ssize_t ret = 0;
+	loff_t pos;
+	int i;
+	struct scatterlist *sg;
+
+	if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC)
+		is_sync = true;
+
+	pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
+	if (unlikely(pos + req->transfer_len > req->ns->size)) {
+		nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
+		return true;
+	}
+
+	memset(&req->f.iocb, 0, sizeof(struct kiocb));
+	for_each_sg(req->sg, sg, req->sg_cnt, i) {
+		bvec_set_page(&req->f.bvec[bv_cnt], sg_page(sg), sg->length,
+			      sg->offset);
+		len += req->f.bvec[bv_cnt].bv_len;
+		total_len += req->f.bvec[bv_cnt].bv_len;
+		bv_cnt++;
+
+		WARN_ON_ONCE((nr_bvec - 1) < 0);
+
+		if (unlikely(is_sync) &&
+		    (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) {
+			ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len, 0);
+			if (ret < 0)
+				goto complete;
+
+			pos += len;
+			bv_cnt = 0;
+			len = 0;
+		}
+		nr_bvec--;
+	}
+
+	if (WARN_ON_ONCE(total_len != req->transfer_len)) {
+		ret = -EIO;
+		goto complete;
+	}
+
+	if (unlikely(is_sync)) {
+		ret = total_len;
+		goto complete;
+	}
+
+	/*
+	 * A NULL ki_complete ask for synchronous execution, which we want
+	 * for the IOCB_NOWAIT case.
+	 */
+	if (!(ki_flags & IOCB_NOWAIT))
+		req->f.iocb.ki_complete = nvmet_file_io_done;
+
+	ret = nvmet_file_submit_bvec(req, pos, bv_cnt, total_len, ki_flags);
+
+	switch (ret) {
+	case -EIOCBQUEUED:
+		return true;
+	case -EAGAIN:
+		if (WARN_ON_ONCE(!(ki_flags & IOCB_NOWAIT)))
+			goto complete;
+		return false;
+	case -EOPNOTSUPP:
+		/*
+		 * For file systems returning error -EOPNOTSUPP, handle
+		 * IOCB_NOWAIT error case separately and retry without
+		 * IOCB_NOWAIT.
+		 */
+		if ((ki_flags & IOCB_NOWAIT))
+			return false;
+		break;
+	}
+
+complete:
+	nvmet_file_io_done(&req->f.iocb, ret);
+	return true;
+}
+
+static void nvmet_file_buffered_io_work(struct work_struct *w)
+{
+	struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
+
+	nvmet_file_execute_io(req, 0);
+}
+
+static void nvmet_file_submit_buffered_io(struct nvmet_req *req)
+{
+	INIT_WORK(&req->f.work, nvmet_file_buffered_io_work);
+	queue_work(buffered_io_wq, &req->f.work);
+}
+
+static void nvmet_file_execute_rw(struct nvmet_req *req)
+{
+	ssize_t nr_bvec = req->sg_cnt;
+
+	if (!nvmet_check_transfer_len(req, nvmet_rw_data_len(req)))
+		return;
+
+	if (!req->sg_cnt || !nr_bvec) {
+		nvmet_req_complete(req, 0);
+		return;
+	}
+
+	if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
+		req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
+				GFP_KERNEL);
+	else
+		req->f.bvec = req->inline_bvec;
+
+	if (unlikely(!req->f.bvec)) {
+		/* fallback under memory pressure */
+		req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
+		req->f.mpool_alloc = true;
+	} else
+		req->f.mpool_alloc = false;
+
+	if (req->ns->buffered_io) {
+		if (likely(!req->f.mpool_alloc) &&
+		    (req->ns->file->f_mode & FMODE_NOWAIT) &&
+		    nvmet_file_execute_io(req, IOCB_NOWAIT))
+			return;
+		nvmet_file_submit_buffered_io(req);
+	} else
+		nvmet_file_execute_io(req, 0);
+}
+
+u16 nvmet_file_flush(struct nvmet_req *req)
+{
+	return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
+}
+
+static void nvmet_file_flush_work(struct work_struct *w)
+{
+	struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
+
+	nvmet_req_complete(req, nvmet_file_flush(req));
+}
+
+static void nvmet_file_execute_flush(struct nvmet_req *req)
+{
+	if (!nvmet_check_transfer_len(req, 0))
+		return;
+	INIT_WORK(&req->f.work, nvmet_file_flush_work);
+	queue_work(nvmet_wq, &req->f.work);
+}
+
+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 status = 0;
+	int ret;
+	int i;
+
+	for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
+		status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
+					sizeof(range));
+		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) {
+			req->error_slba = le64_to_cpu(range.slba);
+			status = errno_to_nvme_status(req, -ENOSPC);
+			break;
+		}
+
+		ret = vfs_fallocate(req->ns->file, mode, offset, len);
+		if (ret && ret != -EOPNOTSUPP) {
+			req->error_slba = le64_to_cpu(range.slba);
+			status = errno_to_nvme_status(req, ret);
+			break;
+		}
+	}
+
+	nvmet_req_complete(req, status);
+}
+
+static void nvmet_file_dsm_work(struct work_struct *w)
+{
+	struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
+
+	switch (le32_to_cpu(req->cmd->dsm.attributes)) {
+	case NVME_DSMGMT_AD:
+		nvmet_file_execute_discard(req);
+		return;
+	case NVME_DSMGMT_IDR:
+	case NVME_DSMGMT_IDW:
+	default:
+		/* Not supported yet */
+		nvmet_req_complete(req, 0);
+		return;
+	}
+}
+
+static void nvmet_file_execute_dsm(struct nvmet_req *req)
+{
+	if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req)))
+		return;
+	INIT_WORK(&req->f.work, nvmet_file_dsm_work);
+	queue_work(nvmet_wq, &req->f.work);
+}
+
+static void nvmet_file_write_zeroes_work(struct work_struct *w)
+{
+	struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
+	struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
+	int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
+	loff_t offset;
+	loff_t len;
+	int ret;
+
+	offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
+	len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
+			req->ns->blksize_shift);
+
+	if (unlikely(offset + len > req->ns->size)) {
+		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 ? errno_to_nvme_status(req, ret) : 0);
+}
+
+static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
+{
+	if (!nvmet_check_transfer_len(req, 0))
+		return;
+	INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
+	queue_work(nvmet_wq, &req->f.work);
+}
+
+u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
+{
+	switch (req->cmd->common.opcode) {
+	case nvme_cmd_read:
+	case nvme_cmd_write:
+		req->execute = nvmet_file_execute_rw;
+		return 0;
+	case nvme_cmd_flush:
+		req->execute = nvmet_file_execute_flush;
+		return 0;
+	case nvme_cmd_dsm:
+		req->execute = nvmet_file_execute_dsm;
+		return 0;
+	case nvme_cmd_write_zeroes:
+		req->execute = nvmet_file_execute_write_zeroes;
+		return 0;
+	default:
+		return nvmet_report_invalid_opcode(req);
+	}
+}