1 files changed, 304 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 000000000000..8c42b3a8c420
--- /dev/null
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -0,0 +1,304 @@
+// 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 "nvmet.h"
+
+#define NVMET_MAX_MPOOL_BVEC		16
+#define NVMET_MIN_MPOOL_OBJ		16
+
+void nvmet_file_ns_disable(struct nvmet_ns *ns)
+{
+	if (ns->file) {
+		mempool_destroy(ns->bvec_pool);
+		ns->bvec_pool = NULL;
+		kmem_cache_destroy(ns->bvec_cache);
+		ns->bvec_cache = NULL;
+		fput(ns->file);
+		ns->file = NULL;
+	}
+}
+
+int nvmet_file_ns_enable(struct nvmet_ns *ns)
+{
+	int ret;
+	struct kstat stat;
+
+	ns->file = filp_open(ns->device_path,
+			O_RDWR | O_LARGEFILE | O_DIRECT, 0);
+	if (IS_ERR(ns->file)) {
+		pr_err("failed to open file %s: (%ld)\n",
+				ns->device_path, PTR_ERR(ns->file));
+		return PTR_ERR(ns->file);
+	}
+
+	ret = vfs_getattr(&ns->file->f_path,
+			&stat, STATX_SIZE, AT_STATX_FORCE_SYNC);
+	if (ret)
+		goto err;
+
+	ns->size = stat.size;
+	ns->blksize_shift = file_inode(ns->file)->i_blkbits;
+
+	ns->bvec_cache = kmem_cache_create("nvmet-bvec",
+			NVMET_MAX_MPOOL_BVEC * sizeof(struct bio_vec),
+			0, SLAB_HWCACHE_ALIGN, NULL);
+	if (!ns->bvec_cache) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab,
+			mempool_free_slab, ns->bvec_cache);
+
+	if (!ns->bvec_pool) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	return ret;
+err:
+	ns->size = 0;
+	ns->blksize_shift = 0;
+	nvmet_file_ns_disable(ns);
+	return ret;
+}
+
+static void nvmet_file_init_bvec(struct bio_vec *bv, struct sg_page_iter *iter)
+{
+	bv->bv_page = sg_page_iter_page(iter);
+	bv->bv_offset = iter->sg->offset;
+	bv->bv_len = PAGE_SIZE - iter->sg->offset;
+}
+
+static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
+		unsigned long nr_segs, size_t count)
+{
+	struct kiocb *iocb = &req->f.iocb;
+	ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter);
+	struct iov_iter iter;
+	int ki_flags = 0, rw;
+	ssize_t ret;
+
+	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 = WRITE;
+	} else {
+		call_iter = req->ns->file->f_op->read_iter;
+		rw = READ;
+	}
+
+	iov_iter_bvec(&iter, ITER_BVEC | rw, req->f.bvec, nr_segs, count);
+
+	iocb->ki_pos = pos;
+	iocb->ki_filp = req->ns->file;
+	iocb->ki_flags = IOCB_DIRECT | ki_flags;
+
+	ret = call_iter(iocb, &iter);
+
+	if (ret != -EIOCBQUEUED && iocb->ki_complete)
+		iocb->ki_complete(iocb, ret, 0);
+
+	return ret;
+}
+
+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);
+
+	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);
+	}
+
+	nvmet_req_complete(req, ret != req->data_len ?
+			NVME_SC_INTERNAL | NVME_SC_DNR : 0);
+}
+
+static void nvmet_file_execute_rw(struct nvmet_req *req)
+{
+	ssize_t nr_bvec = DIV_ROUND_UP(req->data_len, PAGE_SIZE);
+	struct sg_page_iter sg_pg_iter;
+	unsigned long bv_cnt = 0;
+	bool is_sync = false;
+	size_t len = 0, total_len = 0;
+	ssize_t ret = 0;
+	loff_t pos;
+
+	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;
+
+	req->f.mpool_alloc = false;
+	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;
+		if (nr_bvec > NVMET_MAX_MPOOL_BVEC)
+			is_sync = true;
+	}
+
+	pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
+
+	memset(&req->f.iocb, 0, sizeof(struct kiocb));
+	for_each_sg_page(req->sg, &sg_pg_iter, req->sg_cnt, 0) {
+		nvmet_file_init_bvec(&req->f.bvec[bv_cnt], &sg_pg_iter);
+		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);
+			if (ret < 0)
+				goto out;
+			pos += len;
+			bv_cnt = 0;
+			len = 0;
+		}
+		nr_bvec--;
+	}
+
+	if (WARN_ON_ONCE(total_len != req->data_len))
+		ret = -EIO;
+out:
+	if (unlikely(is_sync || ret)) {
+		nvmet_file_io_done(&req->f.iocb, ret < 0 ? ret : total_len, 0);
+		return;
+	}
+	req->f.iocb.ki_complete = nvmet_file_io_done;
+	nvmet_file_submit_bvec(req, pos, bv_cnt, total_len);
+}
+
+static void nvmet_file_flush_work(struct work_struct *w)
+{
+	struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
+	int ret;
+
+	ret = vfs_fsync(req->ns->file, 1);
+
+	nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
+}
+
+static void nvmet_file_execute_flush(struct nvmet_req *req)
+{
+	INIT_WORK(&req->f.work, nvmet_file_flush_work);
+	schedule_work(&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;
+	loff_t len;
+	int i, ret;
+
+	for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
+		if (nvmet_copy_from_sgl(req, i * sizeof(range), &range,
+					sizeof(range)))
+			break;
+		offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
+		len = le32_to_cpu(range.nlb) << req->ns->blksize_shift;
+		ret = vfs_fallocate(req->ns->file, mode, offset, len);
+		if (ret)
+			break;
+	}
+
+	nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
+}
+
+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)
+{
+	INIT_WORK(&req->f.work, nvmet_file_dsm_work);
+	schedule_work(&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);
+
+	ret = vfs_fallocate(req->ns->file, mode, offset, len);
+	nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
+}
+
+static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
+{
+	INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
+	schedule_work(&req->f.work);
+}
+
+u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
+{
+	struct nvme_command *cmd = req->cmd;
+
+	switch (cmd->common.opcode) {
+	case nvme_cmd_read:
+	case nvme_cmd_write:
+		req->execute = nvmet_file_execute_rw;
+		req->data_len = nvmet_rw_len(req);
+		return 0;
+	case nvme_cmd_flush:
+		req->execute = nvmet_file_execute_flush;
+		req->data_len = 0;
+		return 0;
+	case nvme_cmd_dsm:
+		req->execute = nvmet_file_execute_dsm;
+		req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
+			sizeof(struct nvme_dsm_range);
+		return 0;
+	case nvme_cmd_write_zeroes:
+		req->execute = nvmet_file_execute_write_zeroes;
+		req->data_len = 0;
+		return 0;
+	default:
+		pr_err("unhandled cmd for file ns %d on qid %d\n",
+				cmd->common.opcode, req->sq->qid);
+		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
+	}
+}