1 /*******************************************************************************
2 * Filename: target_core_file.c
4 * This file contains the Storage Engine <-> FILEIO transport specific functions
6 * Copyright (c) 2005 PyX Technologies, Inc.
7 * Copyright (c) 2005-2006 SBE, Inc. All Rights Reserved.
8 * Copyright (c) 2007-2010 Rising Tide Systems
9 * Copyright (c) 2008-2010 Linux-iSCSI.org
11 * Nicholas A. Bellinger <nab@kernel.org>
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 ******************************************************************************/
29 #include <linux/string.h>
30 #include <linux/parser.h>
31 #include <linux/timer.h>
32 #include <linux/blkdev.h>
33 #include <linux/slab.h>
34 #include <linux/spinlock.h>
35 #include <linux/module.h>
36 #include <scsi/scsi.h>
37 #include <scsi/scsi_host.h>
39 #include <target/target_core_base.h>
40 #include <target/target_core_backend.h>
42 #include "target_core_file.h"
44 static struct se_subsystem_api fileio_template;
46 /* fd_attach_hba(): (Part of se_subsystem_api_t template)
50 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
52 struct fd_host *fd_host;
54 fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
56 pr_err("Unable to allocate memory for struct fd_host\n");
60 fd_host->fd_host_id = host_id;
62 hba->hba_ptr = fd_host;
64 pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
65 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
66 TARGET_CORE_MOD_VERSION);
67 pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
69 hba->hba_id, fd_host->fd_host_id, FD_MAX_SECTORS);
74 static void fd_detach_hba(struct se_hba *hba)
76 struct fd_host *fd_host = hba->hba_ptr;
78 pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
79 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
85 static void *fd_allocate_virtdevice(struct se_hba *hba, const char *name)
87 struct fd_dev *fd_dev;
88 struct fd_host *fd_host = hba->hba_ptr;
90 fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
92 pr_err("Unable to allocate memory for struct fd_dev\n");
96 fd_dev->fd_host = fd_host;
98 pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
103 /* fd_create_virtdevice(): (Part of se_subsystem_api_t template)
107 static struct se_device *fd_create_virtdevice(
109 struct se_subsystem_dev *se_dev,
113 struct se_device *dev;
114 struct se_dev_limits dev_limits;
115 struct queue_limits *limits;
116 struct fd_dev *fd_dev = p;
117 struct fd_host *fd_host = hba->hba_ptr;
120 struct inode *inode = NULL;
121 int dev_flags = 0, flags, ret = -EINVAL;
123 memset(&dev_limits, 0, sizeof(struct se_dev_limits));
127 dev_p = getname(fd_dev->fd_dev_name);
131 pr_err("getname(%s) failed: %lu\n",
132 fd_dev->fd_dev_name, IS_ERR(dev_p));
133 ret = PTR_ERR(dev_p);
138 flags = O_RDWR | O_CREAT | O_LARGEFILE;
141 * If fd_buffered_io=1 has not been set explicitly (the default),
142 * use O_SYNC to force FILEIO writes to disk.
144 if (!(fd_dev->fbd_flags & FDBD_USE_BUFFERED_IO))
147 file = filp_open(dev_p, flags, 0600);
149 pr_err("filp_open(%s) failed\n", dev_p);
153 if (!file || !file->f_dentry) {
154 pr_err("filp_open(%s) failed\n", dev_p);
157 fd_dev->fd_file = file;
159 * If using a block backend with this struct file, we extract
160 * fd_dev->fd_[block,dev]_size from struct block_device.
162 * Otherwise, we use the passed fd_size= from configfs
164 inode = file->f_mapping->host;
165 if (S_ISBLK(inode->i_mode)) {
166 struct request_queue *q;
167 unsigned long long dev_size;
169 * Setup the local scope queue_limits from struct request_queue->limits
170 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
172 q = bdev_get_queue(inode->i_bdev);
173 limits = &dev_limits.limits;
174 limits->logical_block_size = bdev_logical_block_size(inode->i_bdev);
175 limits->max_hw_sectors = queue_max_hw_sectors(q);
176 limits->max_sectors = queue_max_sectors(q);
178 * Determine the number of bytes from i_size_read() minus
179 * one (1) logical sector from underlying struct block_device
181 fd_dev->fd_block_size = bdev_logical_block_size(inode->i_bdev);
182 dev_size = (i_size_read(file->f_mapping->host) -
183 fd_dev->fd_block_size);
185 pr_debug("FILEIO: Using size: %llu bytes from struct"
186 " block_device blocks: %llu logical_block_size: %d\n",
187 dev_size, div_u64(dev_size, fd_dev->fd_block_size),
188 fd_dev->fd_block_size);
190 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
191 pr_err("FILEIO: Missing fd_dev_size="
192 " parameter, and no backing struct"
197 limits = &dev_limits.limits;
198 limits->logical_block_size = FD_BLOCKSIZE;
199 limits->max_hw_sectors = FD_MAX_SECTORS;
200 limits->max_sectors = FD_MAX_SECTORS;
201 fd_dev->fd_block_size = FD_BLOCKSIZE;
204 dev_limits.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
205 dev_limits.queue_depth = FD_DEVICE_QUEUE_DEPTH;
207 dev = transport_add_device_to_core_hba(hba, &fileio_template,
208 se_dev, dev_flags, fd_dev,
209 &dev_limits, "FILEIO", FD_VERSION);
213 fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
214 fd_dev->fd_queue_depth = dev->queue_depth;
216 pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
217 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
218 fd_dev->fd_dev_name, fd_dev->fd_dev_size);
223 if (fd_dev->fd_file) {
224 filp_close(fd_dev->fd_file, NULL);
225 fd_dev->fd_file = NULL;
231 /* fd_free_device(): (Part of se_subsystem_api_t template)
235 static void fd_free_device(void *p)
237 struct fd_dev *fd_dev = p;
239 if (fd_dev->fd_file) {
240 filp_close(fd_dev->fd_file, NULL);
241 fd_dev->fd_file = NULL;
247 static int fd_do_readv(struct se_cmd *cmd, struct scatterlist *sgl,
250 struct se_device *se_dev = cmd->se_dev;
251 struct fd_dev *dev = se_dev->dev_ptr;
252 struct file *fd = dev->fd_file;
253 struct scatterlist *sg;
256 loff_t pos = (cmd->t_task_lba *
257 se_dev->se_sub_dev->se_dev_attrib.block_size);
260 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
262 pr_err("Unable to allocate fd_do_readv iov[]\n");
266 for_each_sg(sgl, sg, sgl_nents, i) {
267 iov[i].iov_len = sg->length;
268 iov[i].iov_base = sg_virt(sg);
273 ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
278 * Return zeros and GOOD status even if the READ did not return
279 * the expected virt_size for struct file w/o a backing struct
282 if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) {
283 if (ret < 0 || ret != cmd->data_length) {
284 pr_err("vfs_readv() returned %d,"
285 " expecting %d for S_ISBLK\n", ret,
286 (int)cmd->data_length);
287 return (ret < 0 ? ret : -EINVAL);
291 pr_err("vfs_readv() returned %d for non"
300 static int fd_do_writev(struct se_cmd *cmd, struct scatterlist *sgl,
303 struct se_device *se_dev = cmd->se_dev;
304 struct fd_dev *dev = se_dev->dev_ptr;
305 struct file *fd = dev->fd_file;
306 struct scatterlist *sg;
309 loff_t pos = (cmd->t_task_lba *
310 se_dev->se_sub_dev->se_dev_attrib.block_size);
313 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
315 pr_err("Unable to allocate fd_do_writev iov[]\n");
319 for_each_sg(sgl, sg, sgl_nents, i) {
320 iov[i].iov_len = sg->length;
321 iov[i].iov_base = sg_virt(sg);
326 ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
331 if (ret < 0 || ret != cmd->data_length) {
332 pr_err("vfs_writev() returned %d\n", ret);
333 return (ret < 0 ? ret : -EINVAL);
339 static void fd_emulate_sync_cache(struct se_cmd *cmd)
341 struct se_device *dev = cmd->se_dev;
342 struct fd_dev *fd_dev = dev->dev_ptr;
343 int immed = (cmd->t_task_cdb[1] & 0x2);
348 * If the Immediate bit is set, queue up the GOOD response
349 * for this SYNCHRONIZE_CACHE op
352 target_complete_cmd(cmd, SAM_STAT_GOOD);
355 * Determine if we will be flushing the entire device.
357 if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
361 start = cmd->t_task_lba * dev->se_sub_dev->se_dev_attrib.block_size;
362 if (cmd->data_length)
363 end = start + cmd->data_length;
368 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
370 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
376 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
377 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
379 target_complete_cmd(cmd, SAM_STAT_GOOD);
383 static void fd_emulate_write_fua(struct se_cmd *cmd)
385 struct se_device *dev = cmd->se_dev;
386 struct fd_dev *fd_dev = dev->dev_ptr;
387 loff_t start = cmd->t_task_lba *
388 dev->se_sub_dev->se_dev_attrib.block_size;
389 loff_t end = start + cmd->data_length;
392 pr_debug("FILEIO: FUA WRITE LBA: %llu, bytes: %u\n",
393 cmd->t_task_lba, cmd->data_length);
395 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
397 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
400 static int fd_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
401 u32 sgl_nents, enum dma_data_direction data_direction)
403 struct se_device *dev = cmd->se_dev;
407 * Call vectorized fileio functions to map struct scatterlist
408 * physical memory addresses to struct iovec virtual memory.
410 if (data_direction == DMA_FROM_DEVICE) {
411 ret = fd_do_readv(cmd, sgl, sgl_nents);
413 ret = fd_do_writev(cmd, sgl, sgl_nents);
416 dev->se_sub_dev->se_dev_attrib.emulate_write_cache > 0 &&
417 dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
418 (cmd->se_cmd_flags & SCF_FUA)) {
420 * We might need to be a bit smarter here
421 * and return some sense data to let the initiator
422 * know the FUA WRITE cache sync failed..?
424 fd_emulate_write_fua(cmd);
430 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
434 target_complete_cmd(cmd, SAM_STAT_GOOD);
439 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
442 static match_table_t tokens = {
443 {Opt_fd_dev_name, "fd_dev_name=%s"},
444 {Opt_fd_dev_size, "fd_dev_size=%s"},
445 {Opt_fd_buffered_io, "fd_buffered_io=%d"},
449 static ssize_t fd_set_configfs_dev_params(
451 struct se_subsystem_dev *se_dev,
452 const char *page, ssize_t count)
454 struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
455 char *orig, *ptr, *arg_p, *opts;
456 substring_t args[MAX_OPT_ARGS];
457 int ret = 0, arg, token;
459 opts = kstrdup(page, GFP_KERNEL);
465 while ((ptr = strsep(&opts, ",\n")) != NULL) {
469 token = match_token(ptr, tokens, args);
471 case Opt_fd_dev_name:
472 arg_p = match_strdup(&args[0]);
477 snprintf(fd_dev->fd_dev_name, FD_MAX_DEV_NAME,
480 pr_debug("FILEIO: Referencing Path: %s\n",
481 fd_dev->fd_dev_name);
482 fd_dev->fbd_flags |= FBDF_HAS_PATH;
484 case Opt_fd_dev_size:
485 arg_p = match_strdup(&args[0]);
490 ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size);
493 pr_err("strict_strtoull() failed for"
497 pr_debug("FILEIO: Referencing Size: %llu"
498 " bytes\n", fd_dev->fd_dev_size);
499 fd_dev->fbd_flags |= FBDF_HAS_SIZE;
501 case Opt_fd_buffered_io:
502 match_int(args, &arg);
504 pr_err("bogus fd_buffered_io=%d value\n", arg);
509 pr_debug("FILEIO: Using buffered I/O"
510 " operations for struct fd_dev\n");
512 fd_dev->fbd_flags |= FDBD_USE_BUFFERED_IO;
521 return (!ret) ? count : ret;
524 static ssize_t fd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
526 struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
528 if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
529 pr_err("Missing fd_dev_name=\n");
536 static ssize_t fd_show_configfs_dev_params(
538 struct se_subsystem_dev *se_dev,
541 struct fd_dev *fd_dev = se_dev->se_dev_su_ptr;
544 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
545 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s\n",
546 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
547 (fd_dev->fbd_flags & FDBD_USE_BUFFERED_IO) ?
548 "Buffered" : "Synchronous");
552 /* fd_get_device_rev(): (Part of se_subsystem_api_t template)
556 static u32 fd_get_device_rev(struct se_device *dev)
558 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
561 /* fd_get_device_type(): (Part of se_subsystem_api_t template)
565 static u32 fd_get_device_type(struct se_device *dev)
570 static sector_t fd_get_blocks(struct se_device *dev)
572 struct fd_dev *fd_dev = dev->dev_ptr;
573 struct file *f = fd_dev->fd_file;
574 struct inode *i = f->f_mapping->host;
575 unsigned long long dev_size;
577 * When using a file that references an underlying struct block_device,
578 * ensure dev_size is always based on the current inode size in order
579 * to handle underlying block_device resize operations.
581 if (S_ISBLK(i->i_mode))
582 dev_size = (i_size_read(i) - fd_dev->fd_block_size);
584 dev_size = fd_dev->fd_dev_size;
586 return div_u64(dev_size, dev->se_sub_dev->se_dev_attrib.block_size);
589 static struct se_subsystem_api fileio_template = {
591 .owner = THIS_MODULE,
592 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
593 .write_cache_emulated = 1,
594 .fua_write_emulated = 1,
595 .attach_hba = fd_attach_hba,
596 .detach_hba = fd_detach_hba,
597 .allocate_virtdevice = fd_allocate_virtdevice,
598 .create_virtdevice = fd_create_virtdevice,
599 .free_device = fd_free_device,
600 .execute_cmd = fd_execute_cmd,
601 .do_sync_cache = fd_emulate_sync_cache,
602 .check_configfs_dev_params = fd_check_configfs_dev_params,
603 .set_configfs_dev_params = fd_set_configfs_dev_params,
604 .show_configfs_dev_params = fd_show_configfs_dev_params,
605 .get_device_rev = fd_get_device_rev,
606 .get_device_type = fd_get_device_type,
607 .get_blocks = fd_get_blocks,
610 static int __init fileio_module_init(void)
612 return transport_subsystem_register(&fileio_template);
615 static void fileio_module_exit(void)
617 transport_subsystem_release(&fileio_template);
620 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
621 MODULE_AUTHOR("nab@Linux-iSCSI.org");
622 MODULE_LICENSE("GPL");
624 module_init(fileio_module_init);
625 module_exit(fileio_module_exit);