[RFCv3 14/21] tcm: Add FILEIO subsystem plugin

[Nicholas A. Bellinger]

From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

This patch adds the O_SYNC FILEIO subsystem plugin for accessing struct file
using Linux/VFS struct file_operations.  It also includes WriteCache and FUA
Write Emulation support to struct file using fs/sync.c/vfs_fsync_range()

Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
 drivers/target/target_core_file.c | 1052 +++++++++++++++++++++++++++++++++++++
 drivers/target/target_core_file.h |   81 +++
 2 files changed, 1133 insertions(+), 0 deletions(-)
 create mode 100644 drivers/target/target_core_file.c
 create mode 100644 drivers/target/target_core_file.h

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
new file mode 100644
index 0000000..f32a1fc
--- /dev/null
+++ b/drivers/target/target_core_file.c
@@ -0,0 +1,1052 @@
+/*******************************************************************************
+ * Filename:  target_core_file.c
+ *
+ * This file contains the Storage Engine <-> FILEIO transport specific functions
+ *
+ * Copyright (c) 2005 PyX Technologies, Inc.
+ * Copyright (c) 2005-2006 SBE, Inc.  All Rights Reserved.
+ * Copyright (c) 2007-2010 Rising Tide Systems
+ * Copyright (c) 2008-2010 Linux-iSCSI.org
+ *
+ * Nicholas A. Bellinger <nab@xxxxxxxxxx>
+ *
+ * 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/version.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/smp_lock.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_device.h>
+#include <target/target_core_transport.h>
+
+#include "target_core_file.h"
+
+#if 1
+#define DEBUG_FD_CACHE(x...) printk(x)
+#else
+#define DEBUG_FD_CACHE(x...)
+#endif
+
+#if 1
+#define DEBUG_FD_FUA(x...) printk(x)
+#else
+#define DEBUG_FD_FUA(x...)
+#endif
+
+static struct se_subsystem_api fileio_template;
+
+static void __fd_get_dev_info(struct fd_dev *, char *, int *);
+
+/*	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)) {
+		printk(KERN_ERR "Unable to allocate memory for struct fd_host\n");
+		return -1;
+	}
+
+	fd_host->fd_host_id = host_id;
+
+	atomic_set(&hba->left_queue_depth, FD_HBA_QUEUE_DEPTH);
+	atomic_set(&hba->max_queue_depth, FD_HBA_QUEUE_DEPTH);
+	hba->hba_ptr = (void *) fd_host;
+
+	printk(KERN_INFO "CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
+		" Target Core Stack %s\n", hba->hba_id, FD_VERSION,
+		TARGET_CORE_MOD_VERSION);
+	printk(KERN_INFO "CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
+		" Target Core with TCQ Depth: %d MaxSectors: %u\n",
+		hba->hba_id, fd_host->fd_host_id,
+		atomic_read(&hba->max_queue_depth), FD_MAX_SECTORS);
+
+	return 0;
+}
+
+/*	fd_detach_hba(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static int fd_detach_hba(struct se_hba *hba)
+{
+	struct fd_host *fd_host;
+
+	if (!hba->hba_ptr) {
+		printk(KERN_ERR "hba->hba_ptr is NULL!\n");
+		return -1;
+	}
+	fd_host = (struct fd_host *) hba->hba_ptr;
+
+	printk(KERN_INFO "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;
+
+	return 0;
+}
+
+static void *fd_allocate_virtdevice(struct se_hba *hba, const char *name)
+{
+	struct fd_dev *fd_dev;
+	struct fd_host *fd_host = (struct fd_host *) hba->hba_ptr;
+
+	fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
+	if (!(fd_dev)) {
+		printk(KERN_ERR "Unable to allocate memory for struct fd_dev\n");
+		return NULL;
+	}
+
+	fd_dev->fd_host = fd_host;
+
+	printk(KERN_INFO "FILEIO: Allocated fd_dev for %p\n", name);
+
+	return fd_dev;
+}
+
+/*	fd_create_virtdevice(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static struct se_device *fd_create_virtdevice(
+	struct se_hba *hba,
+	struct se_subsystem_dev *se_dev,
+	void *p)
+{
+	char *dev_p = NULL;
+	struct se_device *dev;
+	struct se_dev_limits dev_limits;
+	struct queue_limits *limits;
+	struct fd_dev *fd_dev = (struct fd_dev *) p;
+	struct fd_host *fd_host = (struct fd_host *) hba->hba_ptr;
+	mm_segment_t old_fs;
+	struct file *file;
+	struct inode *inode = NULL;
+	int dev_flags = 0, flags;
+
+	memset(&dev_limits, 0, sizeof(struct se_dev_limits));
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	dev_p = getname(fd_dev->fd_dev_name);
+	set_fs(old_fs);
+
+	if (IS_ERR(dev_p)) {
+		printk(KERN_ERR "getname(%s) failed: %lu\n",
+			fd_dev->fd_dev_name, IS_ERR(dev_p));
+		goto fail;
+	}
+#if 0
+	if (di->no_create_file)
+		flags = O_RDWR | O_LARGEFILE;
+	else
+		flags = O_RDWR | O_CREAT | O_LARGEFILE;
+#else
+	flags = O_RDWR | O_CREAT | O_LARGEFILE;
+#endif
+/*	flags |= O_DIRECT; */
+	/*
+	 * If fd_buffered_io=1 has not been set explictly (the default),
+	 * use O_SYNC to force FILEIO writes to disk.
+	 */
+	if (!(fd_dev->fbd_flags & FDBD_USE_BUFFERED_IO))
+		flags |= O_SYNC;
+
+	file = filp_open(dev_p, flags, 0600);
+
+	if (IS_ERR(file) || !file || !file->f_dentry) {
+		printk(KERN_ERR "filp_open(%s) failed\n", dev_p);
+		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;
+		/*
+		 * Setup the local scope queue_limits from struct request_queue->limits
+		 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
+		 */
+		q = bdev_get_queue(inode->i_bdev);
+		limits = &dev_limits.limits;
+		limits->logical_block_size = bdev_logical_block_size(inode->i_bdev);
+		limits->max_hw_sectors = queue_max_hw_sectors(q);
+		limits->max_sectors = queue_max_sectors(q);
+		/*
+		 * Determine the number of bytes from i_size_read() minus
+		 * one (1) logical sector from underlying struct block_device
+		 */
+		fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
+		fd_dev->fd_dev_size = (i_size_read(file->f_mapping->host) -
+		  		       fd_dev->fd_block_size);
+
+		printk(KERN_INFO "FILEIO: Using size: %llu bytes from struct"
+			" block_device blocks: %llu logical_block_size: %d\n",
+			fd_dev->fd_dev_size,
+			div_u64(fd_dev->fd_dev_size, fd_dev->fd_block_size),
+			fd_dev->fd_block_size);
+	} else {
+		if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
+			printk(KERN_ERR "FILEIO: Missing fd_dev_size="
+				" parameter, and no backing struct"
+				" block_device\n");
+			goto fail;
+		}
+
+		limits = &dev_limits.limits;
+		limits->logical_block_size = FD_BLOCKSIZE;
+		limits->max_hw_sectors = FD_MAX_SECTORS;
+		limits->max_sectors = FD_MAX_SECTORS;
+		fd_dev->fd_block_size = FD_BLOCKSIZE;
+	}
+
+	dev_limits.max_cdb_len = TCM_MAX_COMMAND_SIZE;
+	dev_limits.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
+	dev_limits.queue_depth = FD_DEVICE_QUEUE_DEPTH;
+	/*
+	 * Pass dev_flags for linux_blockdevice_claim_bd or
+	 * linux_blockdevice_claim() from the usage above.
+	 *
+	 * Note that transport_add_device_to_core_hba() will call
+	 * linux_blockdevice_release() internally on failure to
+	 * call bd_release() on the referenced struct block_device.
+	 */
+	dev = transport_add_device_to_core_hba(hba, &fileio_template,
+				se_dev, dev_flags, (void *)fd_dev,
+				&dev_limits, "FILEIO", FD_VERSION);
+	if (!(dev))
+		goto fail;
+
+	fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
+	fd_dev->fd_queue_depth = dev->queue_depth;
+
+	printk(KERN_INFO "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);
+
+	putname(dev_p);
+	return dev;
+fail:
+	if (fd_dev->fd_file) {
+		filp_close(fd_dev->fd_file, NULL);
+		fd_dev->fd_file = NULL;
+	}
+	putname(dev_p);
+	return NULL;
+}
+
+/*	fd_activate_device(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static int fd_activate_device(struct se_device *dev)
+{
+	struct fd_dev *fd_dev = dev->dev_ptr;
+	struct fd_host *fd_host = fd_dev->fd_host;
+
+	printk(KERN_INFO "CORE_FILE[%u] - Activating Device with TCQ: %d at"
+		" FILEIO Device ID: %d\n", fd_host->fd_host_id,
+		fd_dev->fd_queue_depth, fd_dev->fd_dev_id);
+
+	return 0;
+}
+
+/*	fd_deactivate_device(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static void fd_deactivate_device(struct se_device *dev)
+{
+	struct fd_dev *fd_dev = dev->dev_ptr;
+	struct fd_host *fd_host = fd_dev->fd_host;
+
+	printk(KERN_INFO "CORE_FILE[%u] - Deactivating Device with TCQ: %d at"
+		" FILEIO Device ID: %d\n", fd_host->fd_host_id,
+		fd_dev->fd_queue_depth, fd_dev->fd_dev_id);
+
+	return;
+}
+
+/*	fd_free_device(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static void fd_free_device(void *p)
+{
+	struct fd_dev *fd_dev = (struct fd_dev *) p;
+
+	if (fd_dev->fd_file) {
+		filp_close(fd_dev->fd_file, NULL);
+		fd_dev->fd_file = NULL;
+	}
+
+	kfree(fd_dev);
+}
+
+/*	fd_transport_complete(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static int fd_transport_complete(struct se_task *task)
+{
+	return 0;
+}
+
+/*	fd_allocate_request(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static void *fd_allocate_request(
+	struct se_task *task,
+	struct se_device *dev)
+{
+	struct fd_request *fd_req;
+
+	fd_req = kzalloc(sizeof(struct fd_request), GFP_KERNEL);
+	if (!(fd_req)) {
+		printk(KERN_ERR "Unable to allocate struct fd_request\n");
+		return NULL;
+	}
+
+	fd_req->fd_dev = dev->dev_ptr;
+
+	return (void *)fd_req;
+}
+
+static inline int fd_iovec_alloc(struct fd_request *req)
+{
+	req->fd_iovs = kzalloc(sizeof(struct iovec) * req->fd_sg_count,
+				GFP_KERNEL);
+	if (!(req->fd_iovs)) {
+		printk(KERN_ERR "Unable to allocate req->fd_iovs\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int fd_do_readv(struct fd_request *req, struct se_task *task)
+{
+	struct file *fd = req->fd_dev->fd_file;
+	struct scatterlist *sg = task->task_sg;
+	struct iovec *iov;
+	mm_segment_t old_fs;
+	loff_t pos = (req->fd_lba * DEV_ATTRIB(task->se_dev)->block_size);
+	int ret = 0, i;
+
+	iov = kzalloc(sizeof(struct iovec) * req->fd_sg_count, GFP_KERNEL);
+	if (!(iov)) {
+		printk(KERN_ERR "Unable to allocate fd_do_readv iov[]\n");
+		return -1;
+	}
+
+	for (i = 0; i < req->fd_sg_count; i++) {
+		iov[i].iov_len = sg[i].length;
+		iov[i].iov_base = sg_virt(&sg[i]);
+	}
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	ret = vfs_readv(fd, &iov[0], req->fd_sg_count, &pos);
+	set_fs(old_fs);
+
+	kfree(iov);
+	/*
+	 * 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(fd->f_dentry->d_inode->i_mode)) {
+		if (ret < 0 || ret != req->fd_size) {
+			printk(KERN_ERR "vfs_readv() returned %d,"
+				" expecting %d for S_ISBLK\n", ret,
+				(int)req->fd_size);
+			return -1;
+		}
+	} else {
+		if (ret < 0) {
+			printk(KERN_ERR "vfs_readv() returned %d for non"
+				" S_ISBLK\n", ret);
+			return -1;
+		}
+	}
+
+	return 1;
+}
+
+#if 0
+
+static void fd_sendfile_free_DMA(struct se_cmd *cmd)
+{
+	printk(KERN_INFO "Release reference to pages now..\n");
+}
+
+static static int fd_sendactor(
+	read_descriptor_t *desc,
+	struct page *page,
+	unsigned long offset,
+	unsigned long size)
+{
+	unsigned long count = desc->count;
+	struct se_task *task = desc->arg.data;
+	struct fd_request *req = (struct fd_request *) task->transport_req;
+	struct scatterlist *sg = task->task_sg;
+
+	printk(KERN_INFO "page: %p offset: %lu size: %lu\n", page,
+			offset, size);
+
+	__free_page(sg[req->fd_cur_offset].page);
+
+	printk(KERN_INFO "page_address(page): %p\n", page_address(page));
+	sg[req->fd_cur_offset].page = page;
+	sg[req->fd_cur_offset].offset = offset;
+	sg[req->fd_cur_offset].length = size;
+
+	printk(KERN_INFO "sg[%d:%p].page %p length: %d\n", req->fd_cur_offset,
+		&sg[req->fd_cur_offset], sg[req->fd_cur_offset].page,
+		sg[req->fd_cur_offset].length);
+
+	req->fd_cur_size += size;
+	printk(KERN_INFO "fd_cur_size: %u\n", req->fd_cur_size);
+
+	req->fd_cur_offset++;
+
+	desc->count--;
+	desc->written += size;
+	return size;
+}
+
+static int fd_do_sendfile(struct fd_request *req, struct se_task *task)
+{
+	int ret = 0;
+	struct file *fd = req->fd_dev->fd_file;
+
+	if (fd_seek(fd, req->fd_lba, DEV_ATTRIB(task->se_dev)->block_size) < 0)
+		return -1;
+
+	TASK_CMD(task)->transport_free_DMA = &fd_sendfile_free_DMA;
+
+	ret = fd->f_op->sendfile(fd, &fd->f_pos, req->fd_sg_count,
+			fd_sendactor, (void *)task);
+
+	if (ret < 0) {
+		printk(KERN_ERR "fd->f_op->sendfile() returned %d\n", ret);
+		return -1;
+	}
+
+	return 1;
+}
+#endif
+
+static int fd_do_writev(struct fd_request *req, struct se_task *task)
+{
+	struct file *fd = req->fd_dev->fd_file;
+	struct scatterlist *sg = task->task_sg;
+	struct iovec *iov;
+	mm_segment_t old_fs;
+	loff_t pos = (req->fd_lba * DEV_ATTRIB(task->se_dev)->block_size);
+	int ret, i = 0;
+
+	iov = kzalloc(sizeof(struct iovec) * req->fd_sg_count, GFP_KERNEL);
+	if (!(iov)) {
+		printk(KERN_ERR "Unable to allocate fd_do_writev iov[]\n");
+		return -1;
+	}
+
+	for (i = 0; i < req->fd_sg_count; i++) {
+		iov[i].iov_len = sg[i].length;
+		iov[i].iov_base = sg_virt(&sg[i]);
+	}
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	ret = vfs_writev(fd, &iov[0], req->fd_sg_count, &pos);
+	set_fs(old_fs);
+
+	kfree(iov);
+
+	if (ret < 0 || ret != req->fd_size) {
+		printk(KERN_ERR "vfs_writev() returned %d\n", ret);
+		return -1;
+	}
+
+	return 1;
+}
+
+/*
+ * Called from transport_generic_synchronize_cache() to flush the entire
+ * struct file (and possibly backing struct block_device) using vfs_fsync().
+ */
+static int fd_do_sync_cache(struct se_cmd *cmd, int immed)
+{
+	struct fd_dev *fd_dev = cmd->se_dev->dev_ptr;
+	struct file *fd = fd_dev->fd_file;
+	int ret;
+
+	ret = vfs_fsync(fd, 0);
+	if (ret != 0) {
+		printk(KERN_ERR "FILEIO: vfs_fsync(fd, 0) returned: %d\n", ret);
+		return ret;
+	}
+	DEBUG_FD_CACHE("FILEIO: vfs_fsync(fd, 0) called, immed: %d\n", immed);
+	return ret;
+}
+
+/*
+ * Called from transport_generic_synchronize_cache() to flush LBA range
+ */
+int __fd_do_sync_cache_range(
+	struct se_cmd *cmd,
+	unsigned long long lba,
+	u32 size_in_bytes)
+{
+	struct se_device *dev = cmd->se_dev;
+	struct fd_dev *fd_dev = dev->dev_ptr;
+	struct file *fd = fd_dev->fd_file;
+	loff_t start = (lba * DEV_ATTRIB(dev)->block_size);
+	loff_t bytes;
+	int ret, immed = (T_TASK(cmd)->t_task_cdb[1] & 0x2);
+	/*
+	 * If the Immediate bit is set, queue up the GOOD response
+	 * for this SYNCHRONIZE_CACHE op
+	 */
+	if (immed)
+		transport_complete_sync_cache(cmd, 1);
+	/*
+	 * Determine if we will be flushing the entire device.
+	 */
+	if ((T_TASK(cmd)->t_task_lba == 0) && (cmd->data_length == 0)) {
+		ret = fd_do_sync_cache(cmd, immed);		
+		if (!(immed))
+			transport_complete_sync_cache(cmd, (ret == 0) ? 1 : 0);
+		return 0;
+	}
+	/*
+	 * If a explict number of bytes fo flush has been provied by
+	 * the initiator, use this value with vfs_sync_range().  Otherwise
+	 * bytes = LLONG_MAX (matching fs/sync.c:vfs_fsync().
+	 */
+	bytes = (size_in_bytes != 0) ? size_in_bytes : LLONG_MAX;
+	ret = vfs_fsync_range(fd, start, bytes, 0);
+	if (ret != 0) {
+		printk(KERN_ERR "FILEIO: vfs_fsync_range() failed: %d\n", ret);
+		if (!(immed))
+			transport_complete_sync_cache(cmd, 0);
+		return -1;
+	}
+	DEBUG_FD_CACHE("FILEIO: vfs_fsync_range(): LBA: %llu Starting offset:"
+		" %llu, bytes: %llu, immed: %d\n", lba, (unsigned long long)start,
+		(unsigned long long)bytes, immed);
+
+	if (!(immed))
+		transport_complete_sync_cache(cmd, 1);
+
+	return 0;
+}
+
+/*
+ * Called by target_core_transport():transport_emulate_control_cdb()
+ * to emulate SYCHRONIZE_CACHE_*
+ */
+void fd_emulate_sync_cache(struct se_task *task)
+{
+	struct se_cmd *cmd = TASK_CMD(task);
+
+	__fd_do_sync_cache_range(cmd, T_TASK(cmd)->t_task_lba, cmd->data_length);
+}
+
+/*
+ * Tell TCM Core that we are capable of WriteCache emulation for
+ * an underlying struct se_device.
+ */
+int fd_emulated_write_cache(struct se_device *dev)
+{
+	return 1;
+}
+
+int fd_emulated_dpo(struct se_device *dev)
+{
+	return 0;
+}
+/*
+ * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
+ * for TYPE_DISK.
+ */
+int fd_emulated_fua_write(struct se_device *dev)
+{
+	return 1;
+}
+
+int fd_emulated_fua_read(struct se_device *dev)
+{
+	return 0;
+}
+
+/*
+ * WRITE Force Unit Access (FUA) emulation on a per struct se_task
+ * LBA range basis..
+ */
+static inline int fd_emulate_write_fua(
+	struct se_cmd *cmd,
+	struct se_task *task)
+{
+	DEBUG_FD_CACHE("FILEIO: FUA WRITE LBA: %llu, bytes: %u\n",
+			task->task_lba, task->task_size);
+
+	return __fd_do_sync_cache_range(cmd, task->task_lba, task->task_size);
+}
+
+static int fd_do_task(struct se_task *task)
+{
+	struct se_cmd *cmd = task->task_se_cmd;
+	struct se_device *dev = cmd->se_dev;
+	struct fd_request *req = task->transport_req;
+	int ret = 0;
+
+	req->fd_lba = task->task_lba;
+	req->fd_size = task->task_size;
+	/*
+	 * Call vectorized fileio functions to map struct scatterlist
+	 * physical memory addresses to struct iovec virtual memory.
+	 */
+	if (req->fd_data_direction == FD_DATA_READ)
+		ret = fd_do_readv(req, task);
+	else
+		ret = fd_do_writev(req, task);
+
+	if (ret < 0)
+		return ret;
+
+	if (ret) {
+		/*
+		 * Check for Forced Unit Access WRITE emulation
+		 */
+		if ((DEV_ATTRIB(dev)->emulate_write_cache > 0) &&
+		    (DEV_ATTRIB(dev)->emulate_fua_write > 0) &&
+		    (req->fd_data_direction == FD_DATA_WRITE) &&
+		    (T_TASK(cmd)->t_tasks_fua)) {
+			/*
+			 * We might need to be a bit smarter here
+			 * and return some sense data to let the initiator
+			 * know the FUA WRITE cache sync failed..?
+			 */
+			ret = fd_emulate_write_fua(cmd, task);
+			if (ret < 0) {
+				printk(KERN_ERR "FILEIO: fd_emulate"
+					"_write_fua() failed\n");
+			}
+		}
+
+		task->task_scsi_status = GOOD;
+		transport_complete_task(task, 1);
+	}
+
+	return PYX_TRANSPORT_SENT_TO_TRANSPORT;
+}
+
+/*	fd_free_task(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static void fd_free_task(struct se_task *task)
+{
+	struct fd_request *req = task->transport_req;
+
+	kfree(req->fd_iovs);
+	kfree(req);
+}
+
+static ssize_t fd_set_configfs_dev_params(
+	struct se_hba *hba,
+	struct se_subsystem_dev *se_dev,
+	const char *page, ssize_t count)
+{
+	struct fd_dev *fd_dev = (struct fd_dev *) se_dev->se_dev_su_ptr;
+	char *buf, *cur, *ptr, *ptr2;
+	int params = 0;
+	/*
+	 * Make sure we take into account the NULL terminator when copying
+	 * the const buffer here..
+	 */
+	buf = kzalloc(count + 1, GFP_KERNEL);
+	if (!(buf)) {
+		printk(KERN_ERR "Unable to allocate memory for"
+				" temporary buffer\n");
+		return 0;
+	}
+	memcpy(buf, page, count);
+	cur = buf;
+
+	while (cur) {
+		ptr = strstr(cur, "=");
+		if (!(ptr))
+			goto out;
+
+		*ptr = '\0';
+		ptr++;
+
+		ptr2 = strstr(cur, "fd_dev_name");
+		if (ptr2) {
+			transport_check_dev_params_delim(ptr, &cur);
+			ptr = strstrip(ptr);
+			snprintf(fd_dev->fd_dev_name, FD_MAX_DEV_NAME,
+					"%s", ptr);
+			printk(KERN_INFO "FILEIO: Referencing Path: %s\n",
+					fd_dev->fd_dev_name);
+			fd_dev->fbd_flags |= FBDF_HAS_PATH;
+			params++;
+			continue;
+		}
+		ptr2 = strstr(cur, "fd_dev_size");
+		if (ptr2) {
+			transport_check_dev_params_delim(ptr, &cur);
+			if (strict_strtoull(ptr, 0, &fd_dev->fd_dev_size) < 0) {
+				printk(KERN_ERR "strict_strtoull() failed for"
+						" fd_dev_size=\n");
+				continue;
+			}
+			printk(KERN_INFO "FILEIO: Referencing Size: %llu"
+					" bytes\n", fd_dev->fd_dev_size);
+			fd_dev->fbd_flags |= FBDF_HAS_SIZE;
+			params++;
+			continue;
+		}
+		ptr2 = strstr(cur, "fd_buffered_io");
+		if (ptr2) {
+			transport_check_dev_params_delim(ptr, &cur);
+			if (strncmp(ptr, "1", 1))
+				continue;
+
+			printk(KERN_INFO "FILEIO: Using buffered I/O"
+				" operations for struct fd_dev\n");
+
+			fd_dev->fbd_flags |= FDBD_USE_BUFFERED_IO;
+			params++;
+			continue;
+		} else
+			cur = NULL;
+	}
+
+out:
+	kfree(buf);
+	return (params) ? count : -EINVAL;
+}
+
+static ssize_t fd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
+{
+	struct fd_dev *fd_dev = (struct fd_dev *) se_dev->se_dev_su_ptr;
+
+	if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
+		printk(KERN_ERR "Missing fd_dev_name=\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static ssize_t fd_show_configfs_dev_params(
+	struct se_hba *hba,
+	struct se_subsystem_dev *se_dev,
+	char *page)
+{
+	struct fd_dev *fd_dev = (struct fd_dev *) se_dev->se_dev_su_ptr;
+	int bl = 0;
+
+	__fd_get_dev_info(fd_dev, page, &bl);
+	return (ssize_t)bl;
+}
+
+static void fd_get_plugin_info(void *p, char *b, int *bl)
+{
+	*bl += sprintf(b + *bl, "TCM FILEIO Plugin %s\n", FD_VERSION);
+}
+
+static void fd_get_hba_info(struct se_hba *hba, char *b, int *bl)
+{
+	struct fd_host *fd_host = (struct fd_host *)hba->hba_ptr;
+
+	*bl += sprintf(b + *bl, "SE Host ID: %u  FD Host ID: %u\n",
+		 hba->hba_id, fd_host->fd_host_id);
+	*bl += sprintf(b + *bl, "        TCM FILEIO HBA\n");
+}
+
+static void fd_get_dev_info(struct se_device *dev, char *b, int *bl)
+{
+	struct fd_dev *fd_dev = dev->dev_ptr;
+
+	__fd_get_dev_info(fd_dev, b, bl);
+}
+
+static void __fd_get_dev_info(struct fd_dev *fd_dev, char *b, int *bl)
+{
+	*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_USE_BUFFERED_IO) ?
+		"Buffered" : "Synchronous");
+}
+
+/*	fd_map_task_non_SG():
+ *
+ *
+ */
+static void fd_map_task_non_SG(struct se_task *task)
+{
+	struct se_cmd *cmd = TASK_CMD(task);
+	struct fd_request *req = task->transport_req;
+
+	req->fd_bufflen		= task->task_size;
+	req->fd_buf		= (void *) T_TASK(cmd)->t_task_buf;
+	req->fd_sg_count	= 0;
+}
+
+/*	fd_map_task_SG():
+ *
+ *
+ */
+static void fd_map_task_SG(struct se_task *task)
+{
+	struct fd_request *req = task->transport_req;
+
+	req->fd_bufflen		= task->task_size;
+	req->fd_buf		= NULL;
+	req->fd_sg_count	= task->task_sg_num;
+}
+
+/*      fd_CDB_none():
+ *
+ *
+ */
+static int fd_CDB_none(struct se_task *task, u32 size)
+{
+	struct fd_request *req = task->transport_req;
+
+	req->fd_data_direction	= FD_DATA_NONE;
+	req->fd_bufflen		= 0;
+	req->fd_sg_count	= 0;
+	req->fd_buf		= NULL;
+
+	return 0;
+}
+
+/*	fd_CDB_read_non_SG():
+ *
+ *
+ */
+static int fd_CDB_read_non_SG(struct se_task *task, u32 size)
+{
+	struct fd_request *req = task->transport_req;
+
+	req->fd_data_direction = FD_DATA_READ;
+	fd_map_task_non_SG(task);
+
+	return 0;
+}
+
+/*	fd_CDB_read_SG):
+ *
+ *
+ */
+static int fd_CDB_read_SG(struct se_task *task, u32 size)
+{
+	struct fd_request *req = task->transport_req;
+
+	req->fd_data_direction = FD_DATA_READ;
+	fd_map_task_SG(task);
+
+	return req->fd_sg_count;
+}
+
+/*	fd_CDB_write_non_SG():
+ *
+ *
+ */
+static int fd_CDB_write_non_SG(struct se_task *task, u32 size)
+{
+	struct fd_request *req = task->transport_req;
+
+	req->fd_data_direction = FD_DATA_WRITE;
+	fd_map_task_non_SG(task);
+
+	return 0;
+}
+
+/*	fd_CDB_write_SG():
+ *
+ *
+ */
+static int fd_CDB_write_SG(struct se_task *task, u32 size)
+{
+	struct fd_request *req = task->transport_req;
+
+	req->fd_data_direction = FD_DATA_WRITE;
+	fd_map_task_SG(task);
+
+	return req->fd_sg_count;
+}
+
+/*	fd_check_lba():
+ *
+ *
+ */
+static int fd_check_lba(unsigned long long lba, struct se_device *dev)
+{
+	return 0;
+}
+
+/*	fd_check_for_SG(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static int fd_check_for_SG(struct se_task *task)
+{
+	struct fd_request *req = task->transport_req;
+
+	return req->fd_sg_count;
+}
+
+/*	fd_get_cdb(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static unsigned char *fd_get_cdb(struct se_task *task)
+{
+	struct fd_request *req = task->transport_req;
+
+	return req->fd_scsi_cdb;
+}
+
+/*	fd_get_device_rev(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static u32 fd_get_device_rev(struct se_device *dev)
+{
+	return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
+}
+
+/*	fd_get_device_type(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static u32 fd_get_device_type(struct se_device *dev)
+{
+	return TYPE_DISK;
+}
+
+/*	fd_get_dma_length(): (Part of se_subsystem_api_t template)
+ *
+ *
+ */
+static u32 fd_get_dma_length(u32 task_size, struct se_device *dev)
+{
+	return PAGE_SIZE;
+}
+
+static sector_t fd_get_blocks(struct se_device *dev)
+{
+	struct fd_dev *fd_dev = dev->dev_ptr;
+	unsigned long long blocks_long = div_u64(fd_dev->fd_dev_size,
+			DEV_ATTRIB(dev)->block_size);
+
+	return blocks_long;
+}
+
+static struct se_subsystem_api fileio_template = {
+	.name			= "fileio",
+	.type			= FILEIO,
+	.transport_type		= TRANSPORT_PLUGIN_VHBA_PDEV,
+	.external_submod	= 1,
+	.attach_hba		= fd_attach_hba,
+	.detach_hba		= fd_detach_hba,
+	.cdb_none		= fd_CDB_none,
+	.cdb_read_non_SG	= fd_CDB_read_non_SG,
+	.cdb_read_SG		= fd_CDB_read_SG,
+	.cdb_write_non_SG	= fd_CDB_write_non_SG,
+	.cdb_write_SG		= fd_CDB_write_SG,
+	.allocate_virtdevice	= fd_allocate_virtdevice,
+	.create_virtdevice	= fd_create_virtdevice,
+	.activate_device	= fd_activate_device,
+	.deactivate_device	= fd_deactivate_device,
+	.free_device		= fd_free_device,
+	.dpo_emulated		= fd_emulated_dpo,
+	.fua_write_emulated	= fd_emulated_fua_write,
+	.fua_read_emulated	= fd_emulated_fua_read,
+	.write_cache_emulated	= fd_emulated_write_cache,
+	.transport_complete	= fd_transport_complete,
+	.allocate_request	= fd_allocate_request,
+	.do_task		= fd_do_task,
+	.do_discard		= NULL,
+	.do_sync_cache		= fd_emulate_sync_cache,
+	.free_task		= fd_free_task,
+	.check_configfs_dev_params = fd_check_configfs_dev_params,
+	.set_configfs_dev_params = fd_set_configfs_dev_params,
+	.show_configfs_dev_params = fd_show_configfs_dev_params,
+	.get_plugin_info	= fd_get_plugin_info,
+	.get_hba_info		= fd_get_hba_info,
+	.get_dev_info		= fd_get_dev_info,
+	.check_lba		= fd_check_lba,
+	.check_for_SG		= fd_check_for_SG,
+	.get_cdb		= fd_get_cdb,
+	.get_device_rev		= fd_get_device_rev,
+	.get_device_type	= fd_get_device_type,
+	.get_dma_length		= fd_get_dma_length,
+	.get_blocks		= fd_get_blocks,
+	.write_pending		= NULL,
+};
+
+int __init fileio_module_init(void)
+{
+	int ret;
+
+	INIT_LIST_HEAD(&fileio_template.sub_api_list);
+
+	ret = transport_subsystem_register(&fileio_template, THIS_MODULE);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+void fileio_module_exit(void)
+{
+	transport_subsystem_release(&fileio_template);
+}
+
+MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
+MODULE_AUTHOR("nab@xxxxxxxxxxxxxxx");
+MODULE_LICENSE("GPL");
+
+module_init(fileio_module_init);
+module_exit(fileio_module_exit);
diff --git a/drivers/target/target_core_file.h b/drivers/target/target_core_file.h
new file mode 100644
index 0000000..35726f1
--- /dev/null
+++ b/drivers/target/target_core_file.h
@@ -0,0 +1,81 @@
+#ifndef TARGET_CORE_FILE_H
+#define TARGET_CORE_FILE_H
+
+#define FD_VERSION		"4.0"
+
+#define FD_MAX_DEV_NAME		256
+/* Maximum queuedepth for the FILEIO HBA */
+#define FD_HBA_QUEUE_DEPTH	256
+#define FD_DEVICE_QUEUE_DEPTH	32
+#define FD_MAX_DEVICE_QUEUE_DEPTH 128
+#define FD_BLOCKSIZE		512
+#define FD_MAX_SECTORS		1024
+
+#define FD_DATA_READ		1
+#define FD_DATA_WRITE		2
+#define FD_DATA_NONE		3
+
+extern struct se_global *se_global;
+extern struct block_device *__linux_blockdevice_claim(int, int, void *, int *);
+extern struct block_device *linux_blockdevice_claim(int, int, void *);
+extern int linux_blockdevice_release(int, int, struct block_device *);
+extern int linux_blockdevice_check(int, int);
+
+#define RRF_EMULATE_CDB		0x01
+#define RRF_GOT_LBA		0x02
+
+struct fd_request {
+	/* SCSI CDB from iSCSI Command PDU */
+	unsigned char	fd_scsi_cdb[TCM_MAX_COMMAND_SIZE];
+	/* Data Direction */
+	u8		fd_data_direction;
+	/* Total length of request */
+	u32		fd_bufflen;
+	/* RD request flags */
+	u32		fd_req_flags;
+	/* Offset from start of page */
+	u32		fd_offset;
+	u32		fd_cur_size;
+	u32		fd_cur_offset;
+	/* Scatterlist count */
+	u32		fd_sg_count;
+	/* Logical Block Address */
+	unsigned long long	fd_lba;
+	u64		fd_size;
+	struct kiocb	fd_iocb;
+	struct iovec	*fd_iovs;
+	/* Data buffer containing scatterlists(s) or contingous
+	   memory segments */
+	void		*fd_buf;
+	/* FILEIO device */
+	struct fd_dev	*fd_dev;
+} ____cacheline_aligned;
+
+#define FBDF_HAS_PATH		0x01
+#define FBDF_HAS_SIZE		0x02
+#define FDBD_USE_BUFFERED_IO	0x04
+
+struct fd_dev {
+	u32		fbd_flags;
+	unsigned char	fd_dev_name[FD_MAX_DEV_NAME];
+	/* Unique Ramdisk Device ID in Ramdisk HBA */
+	u32		fd_dev_id;
+	/* Number of SG tables in sg_table_array */
+	u32		fd_table_count;
+	u32		fd_queue_depth;
+	u32		fd_block_size;
+	unsigned long long fd_dev_size;
+	struct file	*fd_file;
+	/* FILEIO HBA device is connected to */
+	struct fd_host *fd_host;
+	int (*fd_do_read)(struct fd_request *, struct se_task *);
+	int (*fd_do_write)(struct fd_request *, struct se_task *);
+} ____cacheline_aligned;
+
+struct fd_host {
+	u32		fd_host_dev_id_count;
+	/* Unique FILEIO Host ID */
+	u32		fd_host_id;
+} ____cacheline_aligned;
+
+#endif /* TARGET_CORE_FILE_H */
-- 
1.7.3.1

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