Initial import

1 files changed, 996 insertions, 0 deletions

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
new file mode 100644
index 000000000..3f27bfd81
--- /dev/null
+++ b/drivers/target/target_core_file.c
@@ -0,0 +1,996 @@
+/*******************************************************************************
+ * Filename:  target_core_file.c
+ *
+ * This file contains the Storage Engine <-> FILEIO transport specific functions
+ *
+ * (c) Copyright 2005-2013 Datera, Inc.
+ *
+ * Nicholas A. Bellinger <nab@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ ******************************************************************************/
+
+#include <linux/string.h>
+#include <linux/parser.h>
+#include <linux/timer.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/falloc.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+#include <asm/unaligned.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_backend.h>
+#include <target/target_core_backend_configfs.h>
+
+#include "target_core_file.h"
+
+static inline struct fd_dev *FD_DEV(struct se_device *dev)
+{
+	return container_of(dev, struct fd_dev, dev);
+}
+
+/*	fd_attach_hba(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static int fd_attach_hba(struct se_hba *hba, u32 host_id)
+{
+	struct fd_host *fd_host;
+
+	fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
+	if (!fd_host) {
+		pr_err("Unable to allocate memory for struct fd_host\n");
+		return -ENOMEM;
+	}
+
+	fd_host->fd_host_id = host_id;
+
+	hba->hba_ptr = fd_host;
+
+	pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
+		" Target Core Stack %s\n", hba->hba_id, FD_VERSION,
+		TARGET_CORE_MOD_VERSION);
+	pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic\n",
+		hba->hba_id, fd_host->fd_host_id);
+
+	return 0;
+}
+
+static void fd_detach_hba(struct se_hba *hba)
+{
+	struct fd_host *fd_host = hba->hba_ptr;
+
+	pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
+		" Target Core\n", hba->hba_id, fd_host->fd_host_id);
+
+	kfree(fd_host);
+	hba->hba_ptr = NULL;
+}
+
+static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
+{
+	struct fd_dev *fd_dev;
+	struct fd_host *fd_host = hba->hba_ptr;
+
+	fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
+	if (!fd_dev) {
+		pr_err("Unable to allocate memory for struct fd_dev\n");
+		return NULL;
+	}
+
+	fd_dev->fd_host = fd_host;
+
+	pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
+
+	return &fd_dev->dev;
+}
+
+static int fd_configure_device(struct se_device *dev)
+{
+	struct fd_dev *fd_dev = FD_DEV(dev);
+	struct fd_host *fd_host = dev->se_hba->hba_ptr;
+	struct file *file;
+	struct inode *inode = NULL;
+	int flags, ret = -EINVAL;
+
+	if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
+		pr_err("Missing fd_dev_name=\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Use O_DSYNC by default instead of O_SYNC to forgo syncing
+	 * of pure timestamp updates.
+	 */
+	flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
+
+	/*
+	 * Optionally allow fd_buffered_io=1 to be enabled for people
+	 * who want use the fs buffer cache as an WriteCache mechanism.
+	 *
+	 * This means that in event of a hard failure, there is a risk
+	 * of silent data-loss if the SCSI client has *not* performed a
+	 * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
+	 * to write-out the entire device cache.
+	 */
+	if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
+		pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
+		flags &= ~O_DSYNC;
+	}
+
+	file = filp_open(fd_dev->fd_dev_name, flags, 0600);
+	if (IS_ERR(file)) {
+		pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
+		ret = PTR_ERR(file);
+		goto fail;
+	}
+	fd_dev->fd_file = file;
+	/*
+	 * If using a block backend with this struct file, we extract
+	 * fd_dev->fd_[block,dev]_size from struct block_device.
+	 *
+	 * Otherwise, we use the passed fd_size= from configfs
+	 */
+	inode = file->f_mapping->host;
+	if (S_ISBLK(inode->i_mode)) {
+		struct request_queue *q = bdev_get_queue(inode->i_bdev);
+		unsigned long long dev_size;
+
+		fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
+		/*
+		 * Determine the number of bytes from i_size_read() minus
+		 * one (1) logical sector from underlying struct block_device
+		 */
+		dev_size = (i_size_read(file->f_mapping->host) -
+				       fd_dev->fd_block_size);
+
+		pr_debug("FILEIO: Using size: %llu bytes from struct"
+			" block_device blocks: %llu logical_block_size: %d\n",
+			dev_size, div_u64(dev_size, fd_dev->fd_block_size),
+			fd_dev->fd_block_size);
+		/*
+		 * Check if the underlying struct block_device request_queue supports
+		 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
+		 * in ATA and we need to set TPE=1
+		 */
+		if (blk_queue_discard(q)) {
+			dev->dev_attrib.max_unmap_lba_count =
+				q->limits.max_discard_sectors;
+			/*
+			 * Currently hardcoded to 1 in Linux/SCSI code..
+			 */
+			dev->dev_attrib.max_unmap_block_desc_count = 1;
+			dev->dev_attrib.unmap_granularity =
+				q->limits.discard_granularity >> 9;
+			dev->dev_attrib.unmap_granularity_alignment =
+				q->limits.discard_alignment;
+			pr_debug("IFILE: BLOCK Discard support available,"
+					" disabled by default\n");
+		}
+		/*
+		 * Enable write same emulation for IBLOCK and use 0xFFFF as
+		 * the smaller WRITE_SAME(10) only has a two-byte block count.
+		 */
+		dev->dev_attrib.max_write_same_len = 0xFFFF;
+
+		if (blk_queue_nonrot(q))
+			dev->dev_attrib.is_nonrot = 1;
+	} else {
+		if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
+			pr_err("FILEIO: Missing fd_dev_size="
+				" parameter, and no backing struct"
+				" block_device\n");
+			goto fail;
+		}
+
+		fd_dev->fd_block_size = FD_BLOCKSIZE;
+		/*
+		 * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
+		 */
+		dev->dev_attrib.max_unmap_lba_count = 0x2000;
+		/*
+		 * Currently hardcoded to 1 in Linux/SCSI code..
+		 */
+		dev->dev_attrib.max_unmap_block_desc_count = 1;
+		dev->dev_attrib.unmap_granularity = 1;
+		dev->dev_attrib.unmap_granularity_alignment = 0;
+
+		/*
+		 * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
+		 * based upon struct iovec limit for vfs_writev()
+		 */
+		dev->dev_attrib.max_write_same_len = 0x1000;
+	}
+
+	dev->dev_attrib.hw_block_size = fd_dev->fd_block_size;
+	dev->dev_attrib.max_bytes_per_io = FD_MAX_BYTES;
+	dev->dev_attrib.hw_max_sectors = FD_MAX_BYTES / fd_dev->fd_block_size;
+	dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
+
+	if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
+		pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
+			" with FDBD_HAS_BUFFERED_IO_WCE\n");
+		dev->dev_attrib.emulate_write_cache = 1;
+	}
+
+	fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
+	fd_dev->fd_queue_depth = dev->queue_depth;
+
+	pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
+		" %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
+			fd_dev->fd_dev_name, fd_dev->fd_dev_size);
+
+	return 0;
+fail:
+	if (fd_dev->fd_file) {
+		filp_close(fd_dev->fd_file, NULL);
+		fd_dev->fd_file = NULL;
+	}
+	return ret;
+}
+
+static void fd_free_device(struct se_device *dev)
+{
+	struct fd_dev *fd_dev = FD_DEV(dev);
+
+	if (fd_dev->fd_file) {
+		filp_close(fd_dev->fd_file, NULL);
+		fd_dev->fd_file = NULL;
+	}
+
+	kfree(fd_dev);
+}
+
+static int fd_do_prot_rw(struct se_cmd *cmd, struct fd_prot *fd_prot,
+			 int is_write)
+{
+	struct se_device *se_dev = cmd->se_dev;
+	struct fd_dev *dev = FD_DEV(se_dev);
+	struct file *prot_fd = dev->fd_prot_file;
+	loff_t pos = (cmd->t_task_lba * se_dev->prot_length);
+	unsigned char *buf;
+	u32 prot_size;
+	int rc, ret = 1;
+
+	prot_size = (cmd->data_length / se_dev->dev_attrib.block_size) *
+		     se_dev->prot_length;
+
+	if (!is_write) {
+		fd_prot->prot_buf = kzalloc(prot_size, GFP_KERNEL);
+		if (!fd_prot->prot_buf) {
+			pr_err("Unable to allocate fd_prot->prot_buf\n");
+			return -ENOMEM;
+		}
+		buf = fd_prot->prot_buf;
+
+		fd_prot->prot_sg_nents = 1;
+		fd_prot->prot_sg = kzalloc(sizeof(struct scatterlist),
+					   GFP_KERNEL);
+		if (!fd_prot->prot_sg) {
+			pr_err("Unable to allocate fd_prot->prot_sg\n");
+			kfree(fd_prot->prot_buf);
+			return -ENOMEM;
+		}
+		sg_init_table(fd_prot->prot_sg, fd_prot->prot_sg_nents);
+		sg_set_buf(fd_prot->prot_sg, buf, prot_size);
+	}
+
+	if (is_write) {
+		rc = kernel_write(prot_fd, fd_prot->prot_buf, prot_size, pos);
+		if (rc < 0 || prot_size != rc) {
+			pr_err("kernel_write() for fd_do_prot_rw failed:"
+			       " %d\n", rc);
+			ret = -EINVAL;
+		}
+	} else {
+		rc = kernel_read(prot_fd, pos, fd_prot->prot_buf, prot_size);
+		if (rc < 0) {
+			pr_err("kernel_read() for fd_do_prot_rw failed:"
+			       " %d\n", rc);
+			ret = -EINVAL;
+		}
+	}
+
+	if (is_write || ret < 0) {
+		kfree(fd_prot->prot_sg);
+		kfree(fd_prot->prot_buf);
+	}
+
+	return ret;
+}
+
+static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl,
+		u32 sgl_nents, int is_write)
+{
+	struct se_device *se_dev = cmd->se_dev;
+	struct fd_dev *dev = FD_DEV(se_dev);
+	struct file *fd = dev->fd_file;
+	struct scatterlist *sg;
+	struct iov_iter iter;
+	struct bio_vec *bvec;
+	ssize_t len = 0;
+	loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
+	int ret = 0, i;
+
+	bvec = kcalloc(sgl_nents, sizeof(struct bio_vec), GFP_KERNEL);
+	if (!bvec) {
+		pr_err("Unable to allocate fd_do_readv iov[]\n");
+		return -ENOMEM;
+	}
+
+	for_each_sg(sgl, sg, sgl_nents, i) {
+		bvec[i].bv_page = sg_page(sg);
+		bvec[i].bv_len = sg->length;
+		bvec[i].bv_offset = sg->offset;
+
+		len += sg->length;
+	}
+
+	iov_iter_bvec(&iter, ITER_BVEC, bvec, sgl_nents, len);
+	if (is_write)
+		ret = vfs_iter_write(fd, &iter, &pos);
+	else
+		ret = vfs_iter_read(fd, &iter, &pos);
+
+	kfree(bvec);
+
+	if (is_write) {
+		if (ret < 0 || ret != cmd->data_length) {
+			pr_err("%s() write returned %d\n", __func__, ret);
+			return (ret < 0 ? ret : -EINVAL);
+		}
+	} else {
+		/*
+		 * Return zeros and GOOD status even if the READ did not return
+		 * the expected virt_size for struct file w/o a backing struct
+		 * block_device.
+		 */
+		if (S_ISBLK(file_inode(fd)->i_mode)) {
+			if (ret < 0 || ret != cmd->data_length) {
+				pr_err("%s() returned %d, expecting %u for "
+						"S_ISBLK\n", __func__, ret,
+						cmd->data_length);
+				return (ret < 0 ? ret : -EINVAL);
+			}
+		} else {
+			if (ret < 0) {
+				pr_err("%s() returned %d for non S_ISBLK\n",
+						__func__, ret);
+				return ret;
+			}
+		}
+	}
+	return 1;
+}
+
+static sense_reason_t
+fd_execute_sync_cache(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+	struct fd_dev *fd_dev = FD_DEV(dev);
+	int immed = (cmd->t_task_cdb[1] & 0x2);
+	loff_t start, end;
+	int ret;
+
+	/*
+	 * If the Immediate bit is set, queue up the GOOD response
+	 * for this SYNCHRONIZE_CACHE op
+	 */
+	if (immed)
+		target_complete_cmd(cmd, SAM_STAT_GOOD);
+
+	/*
+	 * Determine if we will be flushing the entire device.
+	 */
+	if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
+		start = 0;
+		end = LLONG_MAX;
+	} else {
+		start = cmd->t_task_lba * dev->dev_attrib.block_size;
+		if (cmd->data_length)
+			end = start + cmd->data_length - 1;
+		else
+			end = LLONG_MAX;
+	}
+
+	ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
+	if (ret != 0)
+		pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
+
+	if (immed)
+		return 0;
+
+	if (ret)
+		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
+	else
+		target_complete_cmd(cmd, SAM_STAT_GOOD);
+
+	return 0;
+}
+
+static sense_reason_t
+fd_execute_write_same(struct se_cmd *cmd)
+{
+	struct se_device *se_dev = cmd->se_dev;
+	struct fd_dev *fd_dev = FD_DEV(se_dev);
+	loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
+	sector_t nolb = sbc_get_write_same_sectors(cmd);
+	struct iov_iter iter;
+	struct bio_vec *bvec;
+	unsigned int len = 0, i;
+	ssize_t ret;
+
+	if (!nolb) {
+		target_complete_cmd(cmd, SAM_STAT_GOOD);
+		return 0;
+	}
+	if (cmd->prot_op) {
+		pr_err("WRITE_SAME: Protection information with FILEIO"
+		       " backends not supported\n");
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+
+	if (cmd->t_data_nents > 1 ||
+	    cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) {
+		pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
+			" block_size: %u\n",
+			cmd->t_data_nents,
+			cmd->t_data_sg[0].length,
+			cmd->se_dev->dev_attrib.block_size);
+		return TCM_INVALID_CDB_FIELD;
+	}
+
+	bvec = kcalloc(nolb, sizeof(struct bio_vec), GFP_KERNEL);
+	if (!bvec)
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+	for (i = 0; i < nolb; i++) {
+		bvec[i].bv_page = sg_page(&cmd->t_data_sg[0]);
+		bvec[i].bv_len = cmd->t_data_sg[0].length;
+		bvec[i].bv_offset = cmd->t_data_sg[0].offset;
+
+		len += se_dev->dev_attrib.block_size;
+	}
+
+	iov_iter_bvec(&iter, ITER_BVEC, bvec, nolb, len);
+	ret = vfs_iter_write(fd_dev->fd_file, &iter, &pos);
+
+	kfree(bvec);
+	if (ret < 0 || ret != len) {
+		pr_err("vfs_iter_write() returned %zd for write same\n", ret);
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+
+	target_complete_cmd(cmd, SAM_STAT_GOOD);
+	return 0;
+}
+
+static int
+fd_do_prot_fill(struct se_device *se_dev, sector_t lba, sector_t nolb,
+		void *buf, size_t bufsize)
+{
+	struct fd_dev *fd_dev = FD_DEV(se_dev);
+	struct file *prot_fd = fd_dev->fd_prot_file;
+	sector_t prot_length, prot;
+	loff_t pos = lba * se_dev->prot_length;
+
+	if (!prot_fd) {
+		pr_err("Unable to locate fd_dev->fd_prot_file\n");
+		return -ENODEV;
+	}
+
+	prot_length = nolb * se_dev->prot_length;
+
+	for (prot = 0; prot < prot_length;) {
+		sector_t len = min_t(sector_t, bufsize, prot_length - prot);
+		ssize_t ret = kernel_write(prot_fd, buf, len, pos + prot);
+
+		if (ret != len) {
+			pr_err("vfs_write to prot file failed: %zd\n", ret);
+			return ret < 0 ? ret : -ENODEV;
+		}
+		prot += ret;
+	}
+
+	return 0;
+}
+
+static int
+fd_do_prot_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
+{
+	void *buf;
+	int rc;
+
+	buf = (void *)__get_free_page(GFP_KERNEL);
+	if (!buf) {
+		pr_err("Unable to allocate FILEIO prot buf\n");
+		return -ENOMEM;
+	}
+	memset(buf, 0xff, PAGE_SIZE);
+
+	rc = fd_do_prot_fill(cmd->se_dev, lba, nolb, buf, PAGE_SIZE);
+
+	free_page((unsigned long)buf);
+
+	return rc;
+}
+
+static sense_reason_t
+fd_do_unmap(struct se_cmd *cmd, void *priv, sector_t lba, sector_t nolb)
+{
+	struct file *file = priv;
+	struct inode *inode = file->f_mapping->host;
+	int ret;
+
+	if (cmd->se_dev->dev_attrib.pi_prot_type) {
+		ret = fd_do_prot_unmap(cmd, lba, nolb);
+		if (ret)
+			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+
+	if (S_ISBLK(inode->i_mode)) {
+		/* The backend is block device, use discard */
+		struct block_device *bdev = inode->i_bdev;
+
+		ret = blkdev_issue_discard(bdev, lba,
+				nolb, GFP_KERNEL, 0);
+		if (ret < 0) {
+			pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
+				ret);
+			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+		}
+	} else {
+		/* The backend is normal file, use fallocate */
+		struct se_device *se_dev = cmd->se_dev;
+		loff_t pos = lba * se_dev->dev_attrib.block_size;
+		unsigned int len = nolb * se_dev->dev_attrib.block_size;
+		int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
+
+		if (!file->f_op->fallocate)
+			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+		ret = file->f_op->fallocate(file, mode, pos, len);
+		if (ret < 0) {
+			pr_warn("FILEIO: fallocate() failed: %d\n", ret);
+			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+		}
+	}
+
+	return 0;
+}
+
+static sense_reason_t
+fd_execute_write_same_unmap(struct se_cmd *cmd)
+{
+	struct se_device *se_dev = cmd->se_dev;
+	struct fd_dev *fd_dev = FD_DEV(se_dev);
+	struct file *file = fd_dev->fd_file;
+	sector_t lba = cmd->t_task_lba;
+	sector_t nolb = sbc_get_write_same_sectors(cmd);
+	sense_reason_t ret;
+
+	if (!nolb) {
+		target_complete_cmd(cmd, SAM_STAT_GOOD);
+		return 0;
+	}
+
+	ret = fd_do_unmap(cmd, file, lba, nolb);
+	if (ret)
+		return ret;
+
+	target_complete_cmd(cmd, GOOD);
+	return 0;
+}
+
+static sense_reason_t
+fd_execute_unmap(struct se_cmd *cmd)
+{
+	struct file *file = FD_DEV(cmd->se_dev)->fd_file;
+
+	return sbc_execute_unmap(cmd, fd_do_unmap, file);
+}
+
+static sense_reason_t
+fd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
+	      enum dma_data_direction data_direction)
+{
+	struct se_device *dev = cmd->se_dev;
+	struct fd_prot fd_prot;
+	sense_reason_t rc;
+	int ret = 0;
+	/*
+	 * We are currently limited by the number of iovecs (2048) per
+	 * single vfs_[writev,readv] call.
+	 */
+	if (cmd->data_length > FD_MAX_BYTES) {
+		pr_err("FILEIO: Not able to process I/O of %u bytes due to"
+		       "FD_MAX_BYTES: %u iovec count limitiation\n",
+			cmd->data_length, FD_MAX_BYTES);
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+	/*
+	 * Call vectorized fileio functions to map struct scatterlist
+	 * physical memory addresses to struct iovec virtual memory.
+	 */
+	if (data_direction == DMA_FROM_DEVICE) {
+		memset(&fd_prot, 0, sizeof(struct fd_prot));
+
+		if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
+			ret = fd_do_prot_rw(cmd, &fd_prot, false);
+			if (ret < 0)
+				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+		}
+
+		ret = fd_do_rw(cmd, sgl, sgl_nents, 0);
+
+		if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
+			u32 sectors = cmd->data_length / dev->dev_attrib.block_size;
+
+			rc = sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors,
+						 0, fd_prot.prot_sg, 0);
+			if (rc) {
+				kfree(fd_prot.prot_sg);
+				kfree(fd_prot.prot_buf);
+				return rc;
+			}
+			kfree(fd_prot.prot_sg);
+			kfree(fd_prot.prot_buf);
+		}
+	} else {
+		memset(&fd_prot, 0, sizeof(struct fd_prot));
+
+		if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
+			u32 sectors = cmd->data_length / dev->dev_attrib.block_size;
+
+			ret = fd_do_prot_rw(cmd, &fd_prot, false);
+			if (ret < 0)
+				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+			rc = sbc_dif_verify_write(cmd, cmd->t_task_lba, sectors,
+						  0, fd_prot.prot_sg, 0);
+			if (rc) {
+				kfree(fd_prot.prot_sg);
+				kfree(fd_prot.prot_buf);
+				return rc;
+			}
+		}
+
+		ret = fd_do_rw(cmd, sgl, sgl_nents, 1);
+		/*
+		 * Perform implicit vfs_fsync_range() for fd_do_writev() ops
+		 * for SCSI WRITEs with Forced Unit Access (FUA) set.
+		 * Allow this to happen independent of WCE=0 setting.
+		 */
+		if (ret > 0 &&
+		    dev->dev_attrib.emulate_fua_write > 0 &&
+		    (cmd->se_cmd_flags & SCF_FUA)) {
+			struct fd_dev *fd_dev = FD_DEV(dev);
+			loff_t start = cmd->t_task_lba *
+				dev->dev_attrib.block_size;
+			loff_t end;
+
+			if (cmd->data_length)
+				end = start + cmd->data_length - 1;
+			else
+				end = LLONG_MAX;
+
+			vfs_fsync_range(fd_dev->fd_file, start, end, 1);
+		}
+
+		if (ret > 0 && cmd->prot_type && dev->dev_attrib.pi_prot_type) {
+			ret = fd_do_prot_rw(cmd, &fd_prot, true);
+			if (ret < 0)
+				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+		}
+	}
+
+	if (ret < 0) {
+		kfree(fd_prot.prot_sg);
+		kfree(fd_prot.prot_buf);
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+
+	if (ret)
+		target_complete_cmd(cmd, SAM_STAT_GOOD);
+	return 0;
+}
+
+enum {
+	Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
+};
+
+static match_table_t tokens = {
+	{Opt_fd_dev_name, "fd_dev_name=%s"},
+	{Opt_fd_dev_size, "fd_dev_size=%s"},
+	{Opt_fd_buffered_io, "fd_buffered_io=%d"},
+	{Opt_err, NULL}
+};
+
+static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
+		const char *page, ssize_t count)
+{
+	struct fd_dev *fd_dev = FD_DEV(dev);
+	char *orig, *ptr, *arg_p, *opts;
+	substring_t args[MAX_OPT_ARGS];
+	int ret = 0, arg, token;
+
+	opts = kstrdup(page, GFP_KERNEL);
+	if (!opts)
+		return -ENOMEM;
+
+	orig = opts;
+
+	while ((ptr = strsep(&opts, ",\n")) != NULL) {
+		if (!*ptr)
+			continue;
+
+		token = match_token(ptr, tokens, args);
+		switch (token) {
+		case Opt_fd_dev_name:
+			if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
+				FD_MAX_DEV_NAME) == 0) {
+				ret = -EINVAL;
+				break;
+			}
+			pr_debug("FILEIO: Referencing Path: %s\n",
+					fd_dev->fd_dev_name);
+			fd_dev->fbd_flags |= FBDF_HAS_PATH;
+			break;
+		case Opt_fd_dev_size:
+			arg_p = match_strdup(&args[0]);
+			if (!arg_p) {
+				ret = -ENOMEM;
+				break;
+			}
+			ret = kstrtoull(arg_p, 0, &fd_dev->fd_dev_size);
+			kfree(arg_p);
+			if (ret < 0) {
+				pr_err("kstrtoull() failed for"
+						" fd_dev_size=\n");
+				goto out;
+			}
+			pr_debug("FILEIO: Referencing Size: %llu"
+					" bytes\n", fd_dev->fd_dev_size);
+			fd_dev->fbd_flags |= FBDF_HAS_SIZE;
+			break;
+		case Opt_fd_buffered_io:
+			ret = match_int(args, &arg);
+			if (ret)
+				goto out;
+			if (arg != 1) {
+				pr_err("bogus fd_buffered_io=%d value\n", arg);
+				ret = -EINVAL;
+				goto out;
+			}
+
+			pr_debug("FILEIO: Using buffered I/O"
+				" operations for struct fd_dev\n");
+
+			fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
+			break;
+		default:
+			break;
+		}
+	}
+
+out:
+	kfree(orig);
+	return (!ret) ? count : ret;
+}
+
+static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
+{
+	struct fd_dev *fd_dev = FD_DEV(dev);
+	ssize_t bl = 0;
+
+	bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
+	bl += sprintf(b + bl, "        File: %s  Size: %llu  Mode: %s\n",
+		fd_dev->fd_dev_name, fd_dev->fd_dev_size,
+		(fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
+		"Buffered-WCE" : "O_DSYNC");
+	return bl;
+}
+
+static sector_t fd_get_blocks(struct se_device *dev)
+{
+	struct fd_dev *fd_dev = FD_DEV(dev);
+	struct file *f = fd_dev->fd_file;
+	struct inode *i = f->f_mapping->host;
+	unsigned long long dev_size;
+	/*
+	 * When using a file that references an underlying struct block_device,
+	 * ensure dev_size is always based on the current inode size in order
+	 * to handle underlying block_device resize operations.
+	 */
+	if (S_ISBLK(i->i_mode))
+		dev_size = i_size_read(i);
+	else
+		dev_size = fd_dev->fd_dev_size;
+
+	return div_u64(dev_size - dev->dev_attrib.block_size,
+		       dev->dev_attrib.block_size);
+}
+
+static int fd_init_prot(struct se_device *dev)
+{
+	struct fd_dev *fd_dev = FD_DEV(dev);
+	struct file *prot_file, *file = fd_dev->fd_file;
+	struct inode *inode;
+	int ret, flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
+	char buf[FD_MAX_DEV_PROT_NAME];
+
+	if (!file) {
+		pr_err("Unable to locate fd_dev->fd_file\n");
+		return -ENODEV;
+	}
+
+	inode = file->f_mapping->host;
+	if (S_ISBLK(inode->i_mode)) {
+		pr_err("FILEIO Protection emulation only supported on"
+		       " !S_ISBLK\n");
+		return -ENOSYS;
+	}
+
+	if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE)
+		flags &= ~O_DSYNC;
+
+	snprintf(buf, FD_MAX_DEV_PROT_NAME, "%s.protection",
+		 fd_dev->fd_dev_name);
+
+	prot_file = filp_open(buf, flags, 0600);
+	if (IS_ERR(prot_file)) {
+		pr_err("filp_open(%s) failed\n", buf);
+		ret = PTR_ERR(prot_file);
+		return ret;
+	}
+	fd_dev->fd_prot_file = prot_file;
+
+	return 0;
+}
+
+static int fd_format_prot(struct se_device *dev)
+{
+	unsigned char *buf;
+	int unit_size = FDBD_FORMAT_UNIT_SIZE * dev->dev_attrib.block_size;
+	int ret;
+
+	if (!dev->dev_attrib.pi_prot_type) {
+		pr_err("Unable to format_prot while pi_prot_type == 0\n");
+		return -ENODEV;
+	}
+
+	buf = vzalloc(unit_size);
+	if (!buf) {
+		pr_err("Unable to allocate FILEIO prot buf\n");
+		return -ENOMEM;
+	}
+
+	pr_debug("Using FILEIO prot_length: %llu\n",
+		 (unsigned long long)(dev->transport->get_blocks(dev) + 1) *
+					dev->prot_length);
+
+	memset(buf, 0xff, unit_size);
+	ret = fd_do_prot_fill(dev, 0, dev->transport->get_blocks(dev) + 1,
+			      buf, unit_size);
+	vfree(buf);
+	return ret;
+}
+
+static void fd_free_prot(struct se_device *dev)
+{
+	struct fd_dev *fd_dev = FD_DEV(dev);
+
+	if (!fd_dev->fd_prot_file)
+		return;
+
+	filp_close(fd_dev->fd_prot_file, NULL);
+	fd_dev->fd_prot_file = NULL;
+}
+
+static struct sbc_ops fd_sbc_ops = {
+	.execute_rw		= fd_execute_rw,
+	.execute_sync_cache	= fd_execute_sync_cache,
+	.execute_write_same	= fd_execute_write_same,
+	.execute_write_same_unmap = fd_execute_write_same_unmap,
+	.execute_unmap		= fd_execute_unmap,
+};
+
+static sense_reason_t
+fd_parse_cdb(struct se_cmd *cmd)
+{
+	return sbc_parse_cdb(cmd, &fd_sbc_ops);
+}
+
+DEF_TB_DEFAULT_ATTRIBS(fileio);
+
+static struct configfs_attribute *fileio_backend_dev_attrs[] = {
+	&fileio_dev_attrib_emulate_model_alias.attr,
+	&fileio_dev_attrib_emulate_dpo.attr,
+	&fileio_dev_attrib_emulate_fua_write.attr,
+	&fileio_dev_attrib_emulate_fua_read.attr,
+	&fileio_dev_attrib_emulate_write_cache.attr,
+	&fileio_dev_attrib_emulate_ua_intlck_ctrl.attr,
+	&fileio_dev_attrib_emulate_tas.attr,
+	&fileio_dev_attrib_emulate_tpu.attr,
+	&fileio_dev_attrib_emulate_tpws.attr,
+	&fileio_dev_attrib_emulate_caw.attr,
+	&fileio_dev_attrib_emulate_3pc.attr,
+	&fileio_dev_attrib_pi_prot_type.attr,
+	&fileio_dev_attrib_hw_pi_prot_type.attr,
+	&fileio_dev_attrib_pi_prot_format.attr,
+	&fileio_dev_attrib_enforce_pr_isids.attr,
+	&fileio_dev_attrib_is_nonrot.attr,
+	&fileio_dev_attrib_emulate_rest_reord.attr,
+	&fileio_dev_attrib_force_pr_aptpl.attr,
+	&fileio_dev_attrib_hw_block_size.attr,
+	&fileio_dev_attrib_block_size.attr,
+	&fileio_dev_attrib_hw_max_sectors.attr,
+	&fileio_dev_attrib_optimal_sectors.attr,
+	&fileio_dev_attrib_hw_queue_depth.attr,
+	&fileio_dev_attrib_queue_depth.attr,
+	&fileio_dev_attrib_max_unmap_lba_count.attr,
+	&fileio_dev_attrib_max_unmap_block_desc_count.attr,
+	&fileio_dev_attrib_unmap_granularity.attr,
+	&fileio_dev_attrib_unmap_granularity_alignment.attr,
+	&fileio_dev_attrib_max_write_same_len.attr,
+	NULL,
+};
+
+static struct se_subsystem_api fileio_template = {
+	.name			= "fileio",
+	.inquiry_prod		= "FILEIO",
+	.inquiry_rev		= FD_VERSION,
+	.owner			= THIS_MODULE,
+	.attach_hba		= fd_attach_hba,
+	.detach_hba		= fd_detach_hba,
+	.alloc_device		= fd_alloc_device,
+	.configure_device	= fd_configure_device,
+	.free_device		= fd_free_device,
+	.parse_cdb		= fd_parse_cdb,
+	.set_configfs_dev_params = fd_set_configfs_dev_params,
+	.show_configfs_dev_params = fd_show_configfs_dev_params,
+	.get_device_type	= sbc_get_device_type,
+	.get_blocks		= fd_get_blocks,
+	.init_prot		= fd_init_prot,
+	.format_prot		= fd_format_prot,
+	.free_prot		= fd_free_prot,
+};
+
+static int __init fileio_module_init(void)
+{
+	struct target_backend_cits *tbc = &fileio_template.tb_cits;
+
+	target_core_setup_sub_cits(&fileio_template);
+	tbc->tb_dev_attrib_cit.ct_attrs = fileio_backend_dev_attrs;
+
+	return transport_subsystem_register(&fileio_template);
+}
+
+static void __exit fileio_module_exit(void)
+{
+	transport_subsystem_release(&fileio_template);
+}
+
+MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
+MODULE_AUTHOR("nab@Linux-iSCSI.org");
+MODULE_LICENSE("GPL");
+
+module_init(fileio_module_init);
+module_exit(fileio_module_exit);