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 * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
195 * based upon struct iovec limit for vfs_writev()
197 dev
->dev_attrib
.max_write_same_len
= 0x1000;
199 pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
200 " %llu total bytes\n", fd_host
->fd_host_id
, fd_dev
->fd_dev_id
,
201 fd_dev
->fd_dev_name
, fd_dev
->fd_dev_size
);
205 if (fd_dev
->fd_file
) {
206 filp_close(fd_dev
->fd_file
, NULL
);
207 fd_dev
->fd_file
= NULL
;
212 static void fd_free_device(struct se_device
*dev
)
214 struct fd_dev
*fd_dev
= FD_DEV(dev
);
216 if (fd_dev
->fd_file
) {
217 filp_close(fd_dev
->fd_file
, NULL
);
218 fd_dev
->fd_file
= NULL
;
224 static int fd_do_rw(struct se_cmd
*cmd
, struct scatterlist
*sgl
,
225 u32 sgl_nents
, int is_write
)
227 struct se_device
*se_dev
= cmd
->se_dev
;
228 struct fd_dev
*dev
= FD_DEV(se_dev
);
229 struct file
*fd
= dev
->fd_file
;
230 struct scatterlist
*sg
;
233 loff_t pos
= (cmd
->t_task_lba
* se_dev
->dev_attrib
.block_size
);
236 iov
= kzalloc(sizeof(struct iovec
) * sgl_nents
, GFP_KERNEL
);
238 pr_err("Unable to allocate fd_do_readv iov[]\n");
242 for_each_sg(sgl
, sg
, sgl_nents
, i
) {
243 iov
[i
].iov_len
= sg
->length
;
244 iov
[i
].iov_base
= kmap(sg_page(sg
)) + sg
->offset
;
251 ret
= vfs_writev(fd
, &iov
[0], sgl_nents
, &pos
);
253 ret
= vfs_readv(fd
, &iov
[0], sgl_nents
, &pos
);
257 for_each_sg(sgl
, sg
, sgl_nents
, i
)
263 if (ret
< 0 || ret
!= cmd
->data_length
) {
264 pr_err("%s() write returned %d\n", __func__
, ret
);
265 return (ret
< 0 ? ret
: -EINVAL
);
269 * Return zeros and GOOD status even if the READ did not return
270 * the expected virt_size for struct file w/o a backing struct
273 if (S_ISBLK(file_inode(fd
)->i_mode
)) {
274 if (ret
< 0 || ret
!= cmd
->data_length
) {
275 pr_err("%s() returned %d, expecting %u for "
276 "S_ISBLK\n", __func__
, ret
,
278 return (ret
< 0 ? ret
: -EINVAL
);
282 pr_err("%s() returned %d for non S_ISBLK\n",
291 static sense_reason_t
292 fd_execute_sync_cache(struct se_cmd
*cmd
)
294 struct se_device
*dev
= cmd
->se_dev
;
295 struct fd_dev
*fd_dev
= FD_DEV(dev
);
296 int immed
= (cmd
->t_task_cdb
[1] & 0x2);
301 * If the Immediate bit is set, queue up the GOOD response
302 * for this SYNCHRONIZE_CACHE op
305 target_complete_cmd(cmd
, SAM_STAT_GOOD
);
308 * Determine if we will be flushing the entire device.
310 if (cmd
->t_task_lba
== 0 && cmd
->data_length
== 0) {
314 start
= cmd
->t_task_lba
* dev
->dev_attrib
.block_size
;
315 if (cmd
->data_length
)
316 end
= start
+ cmd
->data_length
;
321 ret
= vfs_fsync_range(fd_dev
->fd_file
, start
, end
, 1);
323 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret
);
329 target_complete_cmd(cmd
, SAM_STAT_CHECK_CONDITION
);
331 target_complete_cmd(cmd
, SAM_STAT_GOOD
);
336 static unsigned char *
337 fd_setup_write_same_buf(struct se_cmd
*cmd
, struct scatterlist
*sg
,
340 struct se_device
*se_dev
= cmd
->se_dev
;
341 unsigned int block_size
= se_dev
->dev_attrib
.block_size
;
342 unsigned int i
= 0, end
;
343 unsigned char *buf
, *p
, *kmap_buf
;
345 buf
= kzalloc(min_t(unsigned int, len
, PAGE_SIZE
), GFP_KERNEL
);
347 pr_err("Unable to allocate fd_execute_write_same buf\n");
351 kmap_buf
= kmap(sg_page(sg
)) + sg
->offset
;
353 pr_err("kmap() failed in fd_setup_write_same\n");
358 * Fill local *buf to contain multiple WRITE_SAME blocks up to
359 * min(len, PAGE_SIZE)
362 end
= min_t(unsigned int, len
, PAGE_SIZE
);
365 memcpy(p
, kmap_buf
, block_size
);
375 static sense_reason_t
376 fd_execute_write_same(struct se_cmd
*cmd
)
378 struct se_device
*se_dev
= cmd
->se_dev
;
379 struct fd_dev
*fd_dev
= FD_DEV(se_dev
);
380 struct file
*f
= fd_dev
->fd_file
;
381 struct scatterlist
*sg
;
384 sector_t nolb
= sbc_get_write_same_sectors(cmd
);
385 loff_t pos
= cmd
->t_task_lba
* se_dev
->dev_attrib
.block_size
;
386 unsigned int len
, len_tmp
, iov_num
;
391 target_complete_cmd(cmd
, SAM_STAT_GOOD
);
394 sg
= &cmd
->t_data_sg
[0];
396 if (cmd
->t_data_nents
> 1 ||
397 sg
->length
!= cmd
->se_dev
->dev_attrib
.block_size
) {
398 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
399 " block_size: %u\n", cmd
->t_data_nents
, sg
->length
,
400 cmd
->se_dev
->dev_attrib
.block_size
);
401 return TCM_INVALID_CDB_FIELD
;
404 len
= len_tmp
= nolb
* se_dev
->dev_attrib
.block_size
;
405 iov_num
= DIV_ROUND_UP(len
, PAGE_SIZE
);
407 buf
= fd_setup_write_same_buf(cmd
, sg
, len
);
409 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
411 iov
= vzalloc(sizeof(struct iovec
) * iov_num
);
413 pr_err("Unable to allocate fd_execute_write_same iovecs\n");
415 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
418 * Map the single fabric received scatterlist block now populated
419 * in *buf into each iovec for I/O submission.
421 for (i
= 0; i
< iov_num
; i
++) {
422 iov
[i
].iov_base
= buf
;
423 iov
[i
].iov_len
= min_t(unsigned int, len_tmp
, PAGE_SIZE
);
424 len_tmp
-= iov
[i
].iov_len
;
429 rc
= vfs_writev(f
, &iov
[0], iov_num
, &pos
);
435 if (rc
< 0 || rc
!= len
) {
436 pr_err("vfs_writev() returned %d for write same\n", rc
);
437 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
440 target_complete_cmd(cmd
, SAM_STAT_GOOD
);
444 static sense_reason_t
445 fd_execute_rw(struct se_cmd
*cmd
)
447 struct scatterlist
*sgl
= cmd
->t_data_sg
;
448 u32 sgl_nents
= cmd
->t_data_nents
;
449 enum dma_data_direction data_direction
= cmd
->data_direction
;
450 struct se_device
*dev
= cmd
->se_dev
;
454 * Call vectorized fileio functions to map struct scatterlist
455 * physical memory addresses to struct iovec virtual memory.
457 if (data_direction
== DMA_FROM_DEVICE
) {
458 ret
= fd_do_rw(cmd
, sgl
, sgl_nents
, 0);
460 ret
= fd_do_rw(cmd
, sgl
, sgl_nents
, 1);
462 * Perform implict vfs_fsync_range() for fd_do_writev() ops
463 * for SCSI WRITEs with Forced Unit Access (FUA) set.
464 * Allow this to happen independent of WCE=0 setting.
467 dev
->dev_attrib
.emulate_fua_write
> 0 &&
468 (cmd
->se_cmd_flags
& SCF_FUA
)) {
469 struct fd_dev
*fd_dev
= FD_DEV(dev
);
470 loff_t start
= cmd
->t_task_lba
*
471 dev
->dev_attrib
.block_size
;
472 loff_t end
= start
+ cmd
->data_length
;
474 vfs_fsync_range(fd_dev
->fd_file
, start
, end
, 1);
479 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
482 target_complete_cmd(cmd
, SAM_STAT_GOOD
);
487 Opt_fd_dev_name
, Opt_fd_dev_size
, Opt_fd_buffered_io
, Opt_err
490 static match_table_t tokens
= {
491 {Opt_fd_dev_name
, "fd_dev_name=%s"},
492 {Opt_fd_dev_size
, "fd_dev_size=%s"},
493 {Opt_fd_buffered_io
, "fd_buffered_io=%d"},
497 static ssize_t
fd_set_configfs_dev_params(struct se_device
*dev
,
498 const char *page
, ssize_t count
)
500 struct fd_dev
*fd_dev
= FD_DEV(dev
);
501 char *orig
, *ptr
, *arg_p
, *opts
;
502 substring_t args
[MAX_OPT_ARGS
];
503 int ret
= 0, arg
, token
;
505 opts
= kstrdup(page
, GFP_KERNEL
);
511 while ((ptr
= strsep(&opts
, ",\n")) != NULL
) {
515 token
= match_token(ptr
, tokens
, args
);
517 case Opt_fd_dev_name
:
518 if (match_strlcpy(fd_dev
->fd_dev_name
, &args
[0],
519 FD_MAX_DEV_NAME
) == 0) {
523 pr_debug("FILEIO: Referencing Path: %s\n",
524 fd_dev
->fd_dev_name
);
525 fd_dev
->fbd_flags
|= FBDF_HAS_PATH
;
527 case Opt_fd_dev_size
:
528 arg_p
= match_strdup(&args
[0]);
533 ret
= strict_strtoull(arg_p
, 0, &fd_dev
->fd_dev_size
);
536 pr_err("strict_strtoull() failed for"
540 pr_debug("FILEIO: Referencing Size: %llu"
541 " bytes\n", fd_dev
->fd_dev_size
);
542 fd_dev
->fbd_flags
|= FBDF_HAS_SIZE
;
544 case Opt_fd_buffered_io
:
545 match_int(args
, &arg
);
547 pr_err("bogus fd_buffered_io=%d value\n", arg
);
552 pr_debug("FILEIO: Using buffered I/O"
553 " operations for struct fd_dev\n");
555 fd_dev
->fbd_flags
|= FDBD_HAS_BUFFERED_IO_WCE
;
564 return (!ret
) ? count
: ret
;
567 static ssize_t
fd_show_configfs_dev_params(struct se_device
*dev
, char *b
)
569 struct fd_dev
*fd_dev
= FD_DEV(dev
);
572 bl
= sprintf(b
+ bl
, "TCM FILEIO ID: %u", fd_dev
->fd_dev_id
);
573 bl
+= sprintf(b
+ bl
, " File: %s Size: %llu Mode: %s\n",
574 fd_dev
->fd_dev_name
, fd_dev
->fd_dev_size
,
575 (fd_dev
->fbd_flags
& FDBD_HAS_BUFFERED_IO_WCE
) ?
576 "Buffered-WCE" : "O_DSYNC");
580 static sector_t
fd_get_blocks(struct se_device
*dev
)
582 struct fd_dev
*fd_dev
= FD_DEV(dev
);
583 struct file
*f
= fd_dev
->fd_file
;
584 struct inode
*i
= f
->f_mapping
->host
;
585 unsigned long long dev_size
;
587 * When using a file that references an underlying struct block_device,
588 * ensure dev_size is always based on the current inode size in order
589 * to handle underlying block_device resize operations.
591 if (S_ISBLK(i
->i_mode
))
592 dev_size
= (i_size_read(i
) - fd_dev
->fd_block_size
);
594 dev_size
= fd_dev
->fd_dev_size
;
596 return div_u64(dev_size
, dev
->dev_attrib
.block_size
);
599 static struct sbc_ops fd_sbc_ops
= {
600 .execute_rw
= fd_execute_rw
,
601 .execute_sync_cache
= fd_execute_sync_cache
,
602 .execute_write_same
= fd_execute_write_same
,
605 static sense_reason_t
606 fd_parse_cdb(struct se_cmd
*cmd
)
608 return sbc_parse_cdb(cmd
, &fd_sbc_ops
);
611 static struct se_subsystem_api fileio_template
= {
613 .inquiry_prod
= "FILEIO",
614 .inquiry_rev
= FD_VERSION
,
615 .owner
= THIS_MODULE
,
616 .transport_type
= TRANSPORT_PLUGIN_VHBA_PDEV
,
617 .attach_hba
= fd_attach_hba
,
618 .detach_hba
= fd_detach_hba
,
619 .alloc_device
= fd_alloc_device
,
620 .configure_device
= fd_configure_device
,
621 .free_device
= fd_free_device
,
622 .parse_cdb
= fd_parse_cdb
,
623 .set_configfs_dev_params
= fd_set_configfs_dev_params
,
624 .show_configfs_dev_params
= fd_show_configfs_dev_params
,
625 .get_device_type
= sbc_get_device_type
,
626 .get_blocks
= fd_get_blocks
,
629 static int __init
fileio_module_init(void)
631 return transport_subsystem_register(&fileio_template
);
634 static void __exit
fileio_module_exit(void)
636 transport_subsystem_release(&fileio_template
);
639 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
640 MODULE_AUTHOR("nab@Linux-iSCSI.org");
641 MODULE_LICENSE("GPL");
643 module_init(fileio_module_init
);
644 module_exit(fileio_module_exit
);