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 <linux/falloc.h>
34 #include <scsi/scsi.h>
35 #include <scsi/scsi_host.h>
36 #include <asm/unaligned.h>
38 #include <target/target_core_base.h>
39 #include <target/target_core_backend.h>
41 #include "target_core_file.h"
43 static inline struct fd_dev *FD_DEV(struct se_device *dev)
45 return container_of(dev, struct fd_dev, dev);
48 /* fd_attach_hba(): (Part of se_subsystem_api_t template)
52 static int fd_attach_hba(struct se_hba *hba, u32 host_id)
54 struct fd_host *fd_host;
56 fd_host = kzalloc(sizeof(struct fd_host), GFP_KERNEL);
58 pr_err("Unable to allocate memory for struct fd_host\n");
62 fd_host->fd_host_id = host_id;
64 hba->hba_ptr = fd_host;
66 pr_debug("CORE_HBA[%d] - TCM FILEIO HBA Driver %s on Generic"
67 " Target Core Stack %s\n", hba->hba_id, FD_VERSION,
68 TARGET_CORE_MOD_VERSION);
69 pr_debug("CORE_HBA[%d] - Attached FILEIO HBA: %u to Generic"
71 hba->hba_id, fd_host->fd_host_id, FD_MAX_SECTORS);
76 static void fd_detach_hba(struct se_hba *hba)
78 struct fd_host *fd_host = hba->hba_ptr;
80 pr_debug("CORE_HBA[%d] - Detached FILEIO HBA: %u from Generic"
81 " Target Core\n", hba->hba_id, fd_host->fd_host_id);
87 static struct se_device *fd_alloc_device(struct se_hba *hba, const char *name)
89 struct fd_dev *fd_dev;
90 struct fd_host *fd_host = hba->hba_ptr;
92 fd_dev = kzalloc(sizeof(struct fd_dev), GFP_KERNEL);
94 pr_err("Unable to allocate memory for struct fd_dev\n");
98 fd_dev->fd_host = fd_host;
100 pr_debug("FILEIO: Allocated fd_dev for %p\n", name);
105 static int fd_configure_device(struct se_device *dev)
107 struct fd_dev *fd_dev = FD_DEV(dev);
108 struct fd_host *fd_host = dev->se_hba->hba_ptr;
110 struct inode *inode = NULL;
111 int flags, ret = -EINVAL;
113 if (!(fd_dev->fbd_flags & FBDF_HAS_PATH)) {
114 pr_err("Missing fd_dev_name=\n");
119 * Use O_DSYNC by default instead of O_SYNC to forgo syncing
120 * of pure timestamp updates.
122 flags = O_RDWR | O_CREAT | O_LARGEFILE | O_DSYNC;
125 * Optionally allow fd_buffered_io=1 to be enabled for people
126 * who want use the fs buffer cache as an WriteCache mechanism.
128 * This means that in event of a hard failure, there is a risk
129 * of silent data-loss if the SCSI client has *not* performed a
130 * forced unit access (FUA) write, or issued SYNCHRONIZE_CACHE
131 * to write-out the entire device cache.
133 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
134 pr_debug("FILEIO: Disabling O_DSYNC, using buffered FILEIO\n");
138 file = filp_open(fd_dev->fd_dev_name, flags, 0600);
140 pr_err("filp_open(%s) failed\n", fd_dev->fd_dev_name);
144 fd_dev->fd_file = file;
146 * If using a block backend with this struct file, we extract
147 * fd_dev->fd_[block,dev]_size from struct block_device.
149 * Otherwise, we use the passed fd_size= from configfs
151 inode = file->f_mapping->host;
152 if (S_ISBLK(inode->i_mode)) {
153 struct request_queue *q = bdev_get_queue(inode->i_bdev);
154 unsigned long long dev_size;
156 dev->dev_attrib.hw_block_size =
157 bdev_logical_block_size(inode->i_bdev);
158 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
161 * Determine the number of bytes from i_size_read() minus
162 * one (1) logical sector from underlying struct block_device
164 dev_size = (i_size_read(file->f_mapping->host) -
165 fd_dev->fd_block_size);
167 pr_debug("FILEIO: Using size: %llu bytes from struct"
168 " block_device blocks: %llu logical_block_size: %d\n",
169 dev_size, div_u64(dev_size, fd_dev->fd_block_size),
170 fd_dev->fd_block_size);
172 * Check if the underlying struct block_device request_queue supports
173 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
174 * in ATA and we need to set TPE=1
176 if (blk_queue_discard(q)) {
177 dev->dev_attrib.max_unmap_lba_count =
178 q->limits.max_discard_sectors;
180 * Currently hardcoded to 1 in Linux/SCSI code..
182 dev->dev_attrib.max_unmap_block_desc_count = 1;
183 dev->dev_attrib.unmap_granularity =
184 q->limits.discard_granularity >> 9;
185 dev->dev_attrib.unmap_granularity_alignment =
186 q->limits.discard_alignment;
187 pr_debug("IFILE: BLOCK Discard support available,"
188 " disabled by default\n");
191 * Enable write same emulation for IBLOCK and use 0xFFFF as
192 * the smaller WRITE_SAME(10) only has a two-byte block count.
194 dev->dev_attrib.max_write_same_len = 0xFFFF;
196 if (blk_queue_nonrot(q))
197 dev->dev_attrib.is_nonrot = 1;
199 if (!(fd_dev->fbd_flags & FBDF_HAS_SIZE)) {
200 pr_err("FILEIO: Missing fd_dev_size="
201 " parameter, and no backing struct"
206 dev->dev_attrib.hw_block_size = FD_BLOCKSIZE;
207 dev->dev_attrib.hw_max_sectors = FD_MAX_SECTORS;
210 * Limit UNMAP emulation to 8k Number of LBAs (NoLB)
212 dev->dev_attrib.max_unmap_lba_count = 0x2000;
214 * Currently hardcoded to 1 in Linux/SCSI code..
216 dev->dev_attrib.max_unmap_block_desc_count = 1;
217 dev->dev_attrib.unmap_granularity = 1;
218 dev->dev_attrib.unmap_granularity_alignment = 0;
221 * Limit WRITE_SAME w/ UNMAP=0 emulation to 8k Number of LBAs (NoLB)
222 * based upon struct iovec limit for vfs_writev()
224 dev->dev_attrib.max_write_same_len = 0x1000;
227 fd_dev->fd_block_size = dev->dev_attrib.hw_block_size;
229 dev->dev_attrib.hw_queue_depth = FD_MAX_DEVICE_QUEUE_DEPTH;
231 if (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) {
232 pr_debug("FILEIO: Forcing setting of emulate_write_cache=1"
233 " with FDBD_HAS_BUFFERED_IO_WCE\n");
234 dev->dev_attrib.emulate_write_cache = 1;
237 fd_dev->fd_dev_id = fd_host->fd_host_dev_id_count++;
238 fd_dev->fd_queue_depth = dev->queue_depth;
240 pr_debug("CORE_FILE[%u] - Added TCM FILEIO Device ID: %u at %s,"
241 " %llu total bytes\n", fd_host->fd_host_id, fd_dev->fd_dev_id,
242 fd_dev->fd_dev_name, fd_dev->fd_dev_size);
246 if (fd_dev->fd_file) {
247 filp_close(fd_dev->fd_file, NULL);
248 fd_dev->fd_file = NULL;
253 static void fd_free_device(struct se_device *dev)
255 struct fd_dev *fd_dev = FD_DEV(dev);
257 if (fd_dev->fd_file) {
258 filp_close(fd_dev->fd_file, NULL);
259 fd_dev->fd_file = NULL;
265 static int fd_do_rw(struct se_cmd *cmd, struct scatterlist *sgl,
266 u32 sgl_nents, int is_write)
268 struct se_device *se_dev = cmd->se_dev;
269 struct fd_dev *dev = FD_DEV(se_dev);
270 struct file *fd = dev->fd_file;
271 struct scatterlist *sg;
274 loff_t pos = (cmd->t_task_lba * se_dev->dev_attrib.block_size);
277 iov = kzalloc(sizeof(struct iovec) * sgl_nents, GFP_KERNEL);
279 pr_err("Unable to allocate fd_do_readv iov[]\n");
283 for_each_sg(sgl, sg, sgl_nents, i) {
284 iov[i].iov_len = sg->length;
285 iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
292 ret = vfs_writev(fd, &iov[0], sgl_nents, &pos);
294 ret = vfs_readv(fd, &iov[0], sgl_nents, &pos);
298 for_each_sg(sgl, sg, sgl_nents, i)
304 if (ret < 0 || ret != cmd->data_length) {
305 pr_err("%s() write returned %d\n", __func__, ret);
306 return (ret < 0 ? ret : -EINVAL);
310 * Return zeros and GOOD status even if the READ did not return
311 * the expected virt_size for struct file w/o a backing struct
314 if (S_ISBLK(file_inode(fd)->i_mode)) {
315 if (ret < 0 || ret != cmd->data_length) {
316 pr_err("%s() returned %d, expecting %u for "
317 "S_ISBLK\n", __func__, ret,
319 return (ret < 0 ? ret : -EINVAL);
323 pr_err("%s() returned %d for non S_ISBLK\n",
332 static sense_reason_t
333 fd_execute_sync_cache(struct se_cmd *cmd)
335 struct se_device *dev = cmd->se_dev;
336 struct fd_dev *fd_dev = FD_DEV(dev);
337 int immed = (cmd->t_task_cdb[1] & 0x2);
342 * If the Immediate bit is set, queue up the GOOD response
343 * for this SYNCHRONIZE_CACHE op
346 target_complete_cmd(cmd, SAM_STAT_GOOD);
349 * Determine if we will be flushing the entire device.
351 if (cmd->t_task_lba == 0 && cmd->data_length == 0) {
355 start = cmd->t_task_lba * dev->dev_attrib.block_size;
356 if (cmd->data_length)
357 end = start + cmd->data_length;
362 ret = vfs_fsync_range(fd_dev->fd_file, start, end, 1);
364 pr_err("FILEIO: vfs_fsync_range() failed: %d\n", ret);
370 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
372 target_complete_cmd(cmd, SAM_STAT_GOOD);
377 static unsigned char *
378 fd_setup_write_same_buf(struct se_cmd *cmd, struct scatterlist *sg,
381 struct se_device *se_dev = cmd->se_dev;
382 unsigned int block_size = se_dev->dev_attrib.block_size;
383 unsigned int i = 0, end;
384 unsigned char *buf, *p, *kmap_buf;
386 buf = kzalloc(min_t(unsigned int, len, PAGE_SIZE), GFP_KERNEL);
388 pr_err("Unable to allocate fd_execute_write_same buf\n");
392 kmap_buf = kmap(sg_page(sg)) + sg->offset;
394 pr_err("kmap() failed in fd_setup_write_same\n");
399 * Fill local *buf to contain multiple WRITE_SAME blocks up to
400 * min(len, PAGE_SIZE)
403 end = min_t(unsigned int, len, PAGE_SIZE);
406 memcpy(p, kmap_buf, block_size);
416 static sense_reason_t
417 fd_execute_write_same(struct se_cmd *cmd)
419 struct se_device *se_dev = cmd->se_dev;
420 struct fd_dev *fd_dev = FD_DEV(se_dev);
421 struct file *f = fd_dev->fd_file;
422 struct scatterlist *sg;
425 sector_t nolb = sbc_get_write_same_sectors(cmd);
426 loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size;
427 unsigned int len, len_tmp, iov_num;
432 target_complete_cmd(cmd, SAM_STAT_GOOD);
435 sg = &cmd->t_data_sg[0];
437 if (cmd->t_data_nents > 1 ||
438 sg->length != cmd->se_dev->dev_attrib.block_size) {
439 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
440 " block_size: %u\n", cmd->t_data_nents, sg->length,
441 cmd->se_dev->dev_attrib.block_size);
442 return TCM_INVALID_CDB_FIELD;
445 len = len_tmp = nolb * se_dev->dev_attrib.block_size;
446 iov_num = DIV_ROUND_UP(len, PAGE_SIZE);
448 buf = fd_setup_write_same_buf(cmd, sg, len);
450 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
452 iov = vzalloc(sizeof(struct iovec) * iov_num);
454 pr_err("Unable to allocate fd_execute_write_same iovecs\n");
456 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
459 * Map the single fabric received scatterlist block now populated
460 * in *buf into each iovec for I/O submission.
462 for (i = 0; i < iov_num; i++) {
463 iov[i].iov_base = buf;
464 iov[i].iov_len = min_t(unsigned int, len_tmp, PAGE_SIZE);
465 len_tmp -= iov[i].iov_len;
470 rc = vfs_writev(f, &iov[0], iov_num, &pos);
476 if (rc < 0 || rc != len) {
477 pr_err("vfs_writev() returned %d for write same\n", rc);
478 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
481 target_complete_cmd(cmd, SAM_STAT_GOOD);
485 static sense_reason_t
486 fd_do_unmap(struct se_cmd *cmd, void *priv, sector_t lba, sector_t nolb)
488 struct file *file = priv;
489 struct inode *inode = file->f_mapping->host;
492 if (S_ISBLK(inode->i_mode)) {
493 /* The backend is block device, use discard */
494 struct block_device *bdev = inode->i_bdev;
496 ret = blkdev_issue_discard(bdev, lba,
497 nolb, GFP_KERNEL, 0);
499 pr_warn("FILEIO: blkdev_issue_discard() failed: %d\n",
501 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
504 /* The backend is normal file, use fallocate */
505 struct se_device *se_dev = cmd->se_dev;
506 loff_t pos = lba * se_dev->dev_attrib.block_size;
507 unsigned int len = nolb * se_dev->dev_attrib.block_size;
508 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
510 if (!file->f_op->fallocate)
511 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
513 ret = file->f_op->fallocate(file, mode, pos, len);
515 pr_warn("FILEIO: fallocate() failed: %d\n", ret);
516 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
523 static sense_reason_t
524 fd_execute_write_same_unmap(struct se_cmd *cmd)
526 struct se_device *se_dev = cmd->se_dev;
527 struct fd_dev *fd_dev = FD_DEV(se_dev);
528 struct file *file = fd_dev->fd_file;
529 sector_t lba = cmd->t_task_lba;
530 sector_t nolb = sbc_get_write_same_sectors(cmd);
534 target_complete_cmd(cmd, SAM_STAT_GOOD);
538 ret = fd_do_unmap(cmd, file, lba, nolb);
542 target_complete_cmd(cmd, GOOD);
546 static sense_reason_t
547 fd_execute_unmap(struct se_cmd *cmd)
549 struct file *file = FD_DEV(cmd->se_dev)->fd_file;
551 return sbc_execute_unmap(cmd, fd_do_unmap, file);
554 static sense_reason_t
555 fd_execute_rw(struct se_cmd *cmd)
557 struct scatterlist *sgl = cmd->t_data_sg;
558 u32 sgl_nents = cmd->t_data_nents;
559 enum dma_data_direction data_direction = cmd->data_direction;
560 struct se_device *dev = cmd->se_dev;
564 * Call vectorized fileio functions to map struct scatterlist
565 * physical memory addresses to struct iovec virtual memory.
567 if (data_direction == DMA_FROM_DEVICE) {
568 ret = fd_do_rw(cmd, sgl, sgl_nents, 0);
570 ret = fd_do_rw(cmd, sgl, sgl_nents, 1);
572 * Perform implict vfs_fsync_range() for fd_do_writev() ops
573 * for SCSI WRITEs with Forced Unit Access (FUA) set.
574 * Allow this to happen independent of WCE=0 setting.
577 dev->dev_attrib.emulate_fua_write > 0 &&
578 (cmd->se_cmd_flags & SCF_FUA)) {
579 struct fd_dev *fd_dev = FD_DEV(dev);
580 loff_t start = cmd->t_task_lba *
581 dev->dev_attrib.block_size;
582 loff_t end = start + cmd->data_length;
584 vfs_fsync_range(fd_dev->fd_file, start, end, 1);
589 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
592 target_complete_cmd(cmd, SAM_STAT_GOOD);
597 Opt_fd_dev_name, Opt_fd_dev_size, Opt_fd_buffered_io, Opt_err
600 static match_table_t tokens = {
601 {Opt_fd_dev_name, "fd_dev_name=%s"},
602 {Opt_fd_dev_size, "fd_dev_size=%s"},
603 {Opt_fd_buffered_io, "fd_buffered_io=%d"},
607 static ssize_t fd_set_configfs_dev_params(struct se_device *dev,
608 const char *page, ssize_t count)
610 struct fd_dev *fd_dev = FD_DEV(dev);
611 char *orig, *ptr, *arg_p, *opts;
612 substring_t args[MAX_OPT_ARGS];
613 int ret = 0, arg, token;
615 opts = kstrdup(page, GFP_KERNEL);
621 while ((ptr = strsep(&opts, ",\n")) != NULL) {
625 token = match_token(ptr, tokens, args);
627 case Opt_fd_dev_name:
628 if (match_strlcpy(fd_dev->fd_dev_name, &args[0],
629 FD_MAX_DEV_NAME) == 0) {
633 pr_debug("FILEIO: Referencing Path: %s\n",
634 fd_dev->fd_dev_name);
635 fd_dev->fbd_flags |= FBDF_HAS_PATH;
637 case Opt_fd_dev_size:
638 arg_p = match_strdup(&args[0]);
643 ret = strict_strtoull(arg_p, 0, &fd_dev->fd_dev_size);
646 pr_err("strict_strtoull() failed for"
650 pr_debug("FILEIO: Referencing Size: %llu"
651 " bytes\n", fd_dev->fd_dev_size);
652 fd_dev->fbd_flags |= FBDF_HAS_SIZE;
654 case Opt_fd_buffered_io:
655 match_int(args, &arg);
657 pr_err("bogus fd_buffered_io=%d value\n", arg);
662 pr_debug("FILEIO: Using buffered I/O"
663 " operations for struct fd_dev\n");
665 fd_dev->fbd_flags |= FDBD_HAS_BUFFERED_IO_WCE;
674 return (!ret) ? count : ret;
677 static ssize_t fd_show_configfs_dev_params(struct se_device *dev, char *b)
679 struct fd_dev *fd_dev = FD_DEV(dev);
682 bl = sprintf(b + bl, "TCM FILEIO ID: %u", fd_dev->fd_dev_id);
683 bl += sprintf(b + bl, " File: %s Size: %llu Mode: %s\n",
684 fd_dev->fd_dev_name, fd_dev->fd_dev_size,
685 (fd_dev->fbd_flags & FDBD_HAS_BUFFERED_IO_WCE) ?
686 "Buffered-WCE" : "O_DSYNC");
690 static sector_t fd_get_blocks(struct se_device *dev)
692 struct fd_dev *fd_dev = FD_DEV(dev);
693 struct file *f = fd_dev->fd_file;
694 struct inode *i = f->f_mapping->host;
695 unsigned long long dev_size;
697 * When using a file that references an underlying struct block_device,
698 * ensure dev_size is always based on the current inode size in order
699 * to handle underlying block_device resize operations.
701 if (S_ISBLK(i->i_mode))
702 dev_size = (i_size_read(i) - fd_dev->fd_block_size);
704 dev_size = fd_dev->fd_dev_size;
706 return div_u64(dev_size, dev->dev_attrib.block_size);
709 static struct sbc_ops fd_sbc_ops = {
710 .execute_rw = fd_execute_rw,
711 .execute_sync_cache = fd_execute_sync_cache,
712 .execute_write_same = fd_execute_write_same,
713 .execute_write_same_unmap = fd_execute_write_same_unmap,
714 .execute_unmap = fd_execute_unmap,
717 static sense_reason_t
718 fd_parse_cdb(struct se_cmd *cmd)
720 return sbc_parse_cdb(cmd, &fd_sbc_ops);
723 static struct se_subsystem_api fileio_template = {
725 .inquiry_prod = "FILEIO",
726 .inquiry_rev = FD_VERSION,
727 .owner = THIS_MODULE,
728 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
729 .attach_hba = fd_attach_hba,
730 .detach_hba = fd_detach_hba,
731 .alloc_device = fd_alloc_device,
732 .configure_device = fd_configure_device,
733 .free_device = fd_free_device,
734 .parse_cdb = fd_parse_cdb,
735 .set_configfs_dev_params = fd_set_configfs_dev_params,
736 .show_configfs_dev_params = fd_show_configfs_dev_params,
737 .get_device_type = sbc_get_device_type,
738 .get_blocks = fd_get_blocks,
741 static int __init fileio_module_init(void)
743 return transport_subsystem_register(&fileio_template);
746 static void __exit fileio_module_exit(void)
748 transport_subsystem_release(&fileio_template);
751 MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
752 MODULE_AUTHOR("nab@Linux-iSCSI.org");
753 MODULE_LICENSE("GPL");
755 module_init(fileio_module_init);
756 module_exit(fileio_module_exit);