1 /*******************************************************************************
2 * Filename: target_core_file.c
4 * This file contains the Storage Engine <-> FILEIO transport specific functions
6 * (c) Copyright 2005-2012 RisingTide Systems LLC.
8 * Nicholas A. Bellinger <nab@kernel.org>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24 ******************************************************************************/
26 #include <linux/string.h>
27 #include <linux/parser.h>
28 #include <linux/timer.h>
29 #include <linux/blkdev.h>
30 #include <linux/slab.h>
31 #include <linux/spinlock.h>
32 #include <linux/module.h>
33 #include <scsi/scsi.h>
34 #include <scsi/scsi_host.h>
36 #include <target/target_core_base.h>
37 #include <target/target_core_backend.h>
39 #include "target_core_file.h"
41 static inline struct fd_dev *FD_DEV(struct se_device *dev)
43 return container_of(dev, struct fd_dev, dev);
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 struct se_device *fd_alloc_device(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 static int fd_configure_device(struct se_device *dev)
105 struct fd_dev *fd_dev = FD_DEV(dev);
106 struct fd_host *fd_host = dev->se_hba->hba_ptr;
108 struct inode *inode = NULL;
109 int flags, ret = -EINVAL;
111 if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
112 pr_err("Missing fd_dev_name=\n");
117 * Use O_DSYNC by default instead of O_SYNC to forgo syncing
118 * of pure timestamp updates.
120 flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
123 * Optionally allow fd_buffered_io=1 to be enabled for people
124 * who want use the fs buffer cache as an WriteCache mechanism.
126 * This means that in event of a hard failure, there is a risk
127 * of silent data-loss if the SCSI client has *not* performed a
128 * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
129 * to write-out the entire device cache.
131 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
132 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
136 file = filp_open(fd_dev->fd_dev_name, flags, 0600);
138 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
142 fd_dev->fd_file = file;
144 * If using a block backend with this struct file, we extract
145 * fd_dev->fd_[block,dev]_size from struct block_device.
147 * Otherwise, we use the passed fd_size= from configfs
149 inode = file->f_mapping->host;
150 if (S_ISBLK(inode->i_mode)) {
151 struct request_queue *q = bdev_get_queue(inode->i_bdev);
152 unsigned long long dev_size;
154 dev->dev_attrib.hw_block_size =
155 bdev_logical_block_size(inode->i_bdev);
156 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
159 * Determine the number of bytes from i_size_read() minus
160 * one (1) logical sector from underlying struct block_device
162 dev_size = (i_size_read(file->f_mapping->host) -
163 fd_dev->fd_block_size);
165 pr_debug("FILEIO: Using size: %llu bytes from struct"
166 " block_device blocks: %llu logical_block_size: %d\n",
167 dev_size, div_u64(dev_size, fd_dev->fd_block_size),
168 fd_dev->fd_block_size);
170 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
171 pr_err("FILEIO: Missing fd_dev_size="
172 " parameter, and no backing struct"
177 dev->dev_attrib.hw_block_size = FD_BLOCKSIZE;
178 dev->dev_attrib.hw_max_sectors = FD_MAX_SECTORS;
181 fd_dev->fd_block_size = dev->dev_attrib.hw_block_size;
183 dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
185 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
186 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
187 " with FDBD_HAS_BUFFERED_IO_WCE\n");
188 dev->dev_attrib.emulate_write_cache = 1;
191 fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
192 fd_dev->fd_queue_depth = dev->queue_depth;
194 pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
195 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
196 fd_dev->fd_dev_name, fd_dev->fd_dev_size);
200 if (fd_dev->fd_file) {
201 filp_close(fd_dev->fd_file, NULL);
202 fd_dev->fd_file = NULL;
207 static void fd_free_device(struct se_device *dev)
209 struct fd_dev *fd_dev = FD_DEV(dev);
211 if (fd_dev->fd_file) {
212 filp_close(fd_dev->fd_file, NULL);
213 fd_dev->fd_file = NULL;
219 static int fd_do_readv(struct se_cmd *cmd, struct scatterlist *sgl,
222 struct se_device *se_dev = cmd->se_dev;
223 struct fd_dev *dev = FD_DEV(se_dev);
224 struct file *fd = dev->fd_file;
225 struct scatterlist *sg;
228 loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
231 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
233 pr_err("Unable to allocate fd_do_readv iov[]\n");
237 for_each_sg(sgl, sg, sgl_nents, i) {
238 iov[i].iov_len = sg->length;
239 iov[i].iov_base = sg_virt(sg);
244 ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
249 * Return zeros and GOOD status even if the READ did not return
250 * the expected virt_size for struct file w/o a backing struct
253 if (S_ISBLK(fd->f_dentry->d_inode->i_mode)) {
254 if (ret < 0 || ret != cmd->data_length) {
255 pr_err("vfs_readv() returned %d,"
256 " expecting %d for S_ISBLK\n", ret,
257 (int)cmd->data_length);
258 return (ret < 0 ? ret : -EINVAL);
262 pr_err("vfs_readv() returned %d for non"
271 static int fd_do_writev(struct se_cmd *cmd, struct scatterlist *sgl,
274 struct se_device *se_dev = cmd->se_dev;
275 struct fd_dev *dev = FD_DEV(se_dev);
276 struct file *fd = dev->fd_file;
277 struct scatterlist *sg;
280 loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
283 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
285 pr_err("Unable to allocate fd_do_writev iov[]\n");
289 for_each_sg(sgl, sg, sgl_nents, i) {
290 iov[i].iov_len = sg->length;
291 iov[i].iov_base = sg_virt(sg);
296 ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
301 if (ret < 0 || ret != cmd->data_length) {
302 pr_err("vfs_writev() returned %d\n", ret);
303 return (ret < 0 ? ret : -EINVAL);
309 static sense_reason_t
310 fd_execute_sync_cache(struct se_cmd *cmd)
312 struct se_device *dev = cmd->se_dev;
313 struct fd_dev *fd_dev = FD_DEV(dev);
314 int immed = (cmd->t_task_cdb[1] & 0x2);
319 * If the Immediate bit is set, queue up the GOOD response
320 * for this SYNCHRONIZE_CACHE op
323 target_complete_cmd(cmd, SAM_STAT_GOOD);
326 * Determine if we will be flushing the entire device.
328 if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
332 start = cmd->t_task_lba * dev->dev_attrib.block_size;
333 if (cmd->data_length)
334 end = start + cmd->data_length;
339 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
341 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
347 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
349 target_complete_cmd(cmd, SAM_STAT_GOOD);
354 static sense_reason_t
355 fd_execute_rw(struct se_cmd *cmd)
357 struct scatterlist *sgl = cmd->t_data_sg;
358 u32 sgl_nents = cmd->t_data_nents;
359 enum dma_data_direction data_direction = cmd->data_direction;
360 struct se_device *dev = cmd->se_dev;
364 * Call vectorized fileio functions to map struct scatterlist
365 * physical memory addresses to struct iovec virtual memory.
367 if (data_direction == DMA_FROM_DEVICE) {
368 ret = fd_do_readv(cmd, sgl, sgl_nents);
370 ret = fd_do_writev(cmd, sgl, sgl_nents);
372 * Perform implict vfs_fsync_range() for fd_do_writev() ops
373 * for SCSI WRITEs with Forced Unit Access (FUA) set.
374 * Allow this to happen independent of WCE=0 setting.
377 dev->dev_attrib.emulate_fua_write > 0 &&
378 (cmd->se_cmd_flags & SCF_FUA)) {
379 struct fd_dev *fd_dev = FD_DEV(dev);
380 loff_t start = cmd->t_task_lba *
381 dev->dev_attrib.block_size;
382 loff_t end = start + cmd->data_length;
384 vfs_fsync_range(fd_dev->fd_file, start, end, 1);
389 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
392 target_complete_cmd(cmd, SAM_STAT_GOOD);
397 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
400 static match_table_t tokens = {
401 {Opt_fd_dev_name, "fd_dev_name=%s"},
402 {Opt_fd_dev_size, "fd_dev_size=%s"},
403 {Opt_fd_buffered_io, "fd_buffered_io=%d"},
407 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
408 const char *page, ssize_t count)
410 struct fd_dev *fd_dev = FD_DEV(dev);
411 char *orig, *ptr, *arg_p, *opts;
412 substring_t args[MAX_OPT_ARGS];
413 int ret = 0, arg, token;
415 opts = kstrdup(page, GFP_KERNEL);
421 while ((ptr = strsep(&opts, ",\n")) != NULL) {
425 token = match_token(ptr, tokens, args);
427 case Opt_fd_dev_name:
428 if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
429 FD_MAX_DEV_NAME) == 0) {
433 pr_debug("FILEIO: Referencing Path: %s\n",
434 fd_dev->fd_dev_name);
435 fd_dev->fbd_flags |= FBDF_HAS_PATH;
437 case Opt_fd_dev_size:
438 arg_p = match_strdup(&args[0]);
443 ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size);
446 pr_err("strict_strtoull() failed for"
450 pr_debug("FILEIO: Referencing Size: %llu"
451 " bytes\n", fd_dev->fd_dev_size);
452 fd_dev->fbd_flags |= FBDF_HAS_SIZE;
454 case Opt_fd_buffered_io:
455 match_int(args, &arg);
457 pr_err("bogus fd_buffered_io=%d value\n", arg);
462 pr_debug("FILEIO: Using buffered I/O"
463 " operations for struct fd_dev\n");
465 fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
474 return (!ret) ? count : ret;
477 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
479 struct fd_dev *fd_dev = FD_DEV(dev);
482 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
483 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s\n",
484 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
485 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
486 "Buffered-WCE" : "O_DSYNC");
490 static sector_t fd_get_blocks(struct se_device *dev)
492 struct fd_dev *fd_dev = FD_DEV(dev);
493 struct file *f = fd_dev->fd_file;
494 struct inode *i = f->f_mapping->host;
495 unsigned long long dev_size;
497 * When using a file that references an underlying struct block_device,
498 * ensure dev_size is always based on the current inode size in order
499 * to handle underlying block_device resize operations.
501 if (S_ISBLK(i->i_mode))
502 dev_size = (i_size_read(i) - fd_dev->fd_block_size);
504 dev_size = fd_dev->fd_dev_size;
506 return div_u64(dev_size, dev->dev_attrib.block_size);
509 static struct sbc_ops fd_sbc_ops = {
510 .execute_rw = fd_execute_rw,
511 .execute_sync_cache = fd_execute_sync_cache,
514 static sense_reason_t
515 fd_parse_cdb(struct se_cmd *cmd)
517 return sbc_parse_cdb(cmd, &fd_sbc_ops);
520 static struct se_subsystem_api fileio_template = {
522 .inquiry_prod = "FILEIO",
523 .inquiry_rev = FD_VERSION,
524 .owner = THIS_MODULE,
525 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
526 .attach_hba = fd_attach_hba,
527 .detach_hba = fd_detach_hba,
528 .alloc_device = fd_alloc_device,
529 .configure_device = fd_configure_device,
530 .free_device = fd_free_device,
531 .parse_cdb = fd_parse_cdb,
532 .set_configfs_dev_params = fd_set_configfs_dev_params,
533 .show_configfs_dev_params = fd_show_configfs_dev_params,
534 .get_device_type = sbc_get_device_type,
535 .get_blocks = fd_get_blocks,
538 static int __init fileio_module_init(void)
540 return transport_subsystem_register(&fileio_template);
543 static void fileio_module_exit(void)
545 transport_subsystem_release(&fileio_template);
548 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
549 MODULE_AUTHOR("nab@Linux-iSCSI.org");
550 MODULE_LICENSE("GPL");
552 module_init(fileio_module_init);
553 module_exit(fileio_module_exit);