1 /*******************************************************************************
2 * Filename: target_core_iblock.c
4 * This file contains the Storage Engine <-> Linux BlockIO transport
7 * (c) Copyright 2003-2013 Datera, Inc.
9 * Nicholas A. Bellinger <nab@kernel.org>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 ******************************************************************************/
27 #include <linux/string.h>
28 #include <linux/parser.h>
29 #include <linux/timer.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/spinlock.h>
34 #include <linux/bio.h>
35 #include <linux/genhd.h>
36 #include <linux/file.h>
37 #include <linux/module.h>
38 #include <scsi/scsi_proto.h>
39 #include <asm/unaligned.h>
41 #include <target/target_core_base.h>
42 #include <target/target_core_backend.h>
44 #include "target_core_iblock.h"
46 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
47 #define IBLOCK_BIO_POOL_SIZE 128
49 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
51 return container_of(dev, struct iblock_dev, dev);
55 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
57 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
58 " Generic Target Core Stack %s\n", hba->hba_id,
59 IBLOCK_VERSION, TARGET_CORE_VERSION);
63 static void iblock_detach_hba(struct se_hba *hba)
67 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
69 struct iblock_dev *ib_dev = NULL;
71 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
73 pr_err("Unable to allocate struct iblock_dev\n");
77 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
82 static int iblock_configure_device(struct se_device *dev)
84 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
85 struct request_queue *q;
86 struct block_device *bd = NULL;
87 struct blk_integrity *bi;
91 if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
92 pr_err("Missing udev_path= parameters for IBLOCK\n");
96 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
97 if (!ib_dev->ibd_bio_set) {
98 pr_err("IBLOCK: Unable to create bioset\n");
102 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
103 ib_dev->ibd_udev_path);
105 mode = FMODE_READ|FMODE_EXCL;
106 if (!ib_dev->ibd_readonly)
109 dev->dev_flags |= DF_READ_ONLY;
111 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
114 goto out_free_bioset;
118 q = bdev_get_queue(bd);
120 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
121 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
122 dev->dev_attrib.hw_queue_depth = q->nr_requests;
124 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
125 pr_debug("IBLOCK: BLOCK Discard support available,"
126 " disabled by default\n");
129 * Enable write same emulation for IBLOCK and use 0xFFFF as
130 * the smaller WRITE_SAME(10) only has a two-byte block count.
132 dev->dev_attrib.max_write_same_len = 0xFFFF;
134 if (blk_queue_nonrot(q))
135 dev->dev_attrib.is_nonrot = 1;
137 bi = bdev_get_integrity(bd);
139 struct bio_set *bs = ib_dev->ibd_bio_set;
141 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
142 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
143 pr_err("IBLOCK export of blk_integrity: %s not"
144 " supported\n", bi->profile->name);
149 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
150 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
151 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
152 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
155 if (dev->dev_attrib.pi_prot_type) {
156 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
157 pr_err("Unable to allocate bioset for PI\n");
161 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
162 bs->bio_integrity_pool);
164 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
170 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
172 bioset_free(ib_dev->ibd_bio_set);
173 ib_dev->ibd_bio_set = NULL;
178 static void iblock_dev_call_rcu(struct rcu_head *p)
180 struct se_device *dev = container_of(p, struct se_device, rcu_head);
181 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
186 static void iblock_free_device(struct se_device *dev)
188 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
190 if (ib_dev->ibd_bd != NULL)
191 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
192 if (ib_dev->ibd_bio_set != NULL)
193 bioset_free(ib_dev->ibd_bio_set);
195 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
198 static unsigned long long iblock_emulate_read_cap_with_block_size(
199 struct se_device *dev,
200 struct block_device *bd,
201 struct request_queue *q)
203 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
204 bdev_logical_block_size(bd)) - 1);
205 u32 block_size = bdev_logical_block_size(bd);
207 if (block_size == dev->dev_attrib.block_size)
210 switch (block_size) {
212 switch (dev->dev_attrib.block_size) {
226 switch (dev->dev_attrib.block_size) {
241 switch (dev->dev_attrib.block_size) {
256 switch (dev->dev_attrib.block_size) {
277 static void iblock_complete_cmd(struct se_cmd *cmd)
279 struct iblock_req *ibr = cmd->priv;
282 if (!atomic_dec_and_test(&ibr->pending))
285 if (atomic_read(&ibr->ib_bio_err_cnt))
286 status = SAM_STAT_CHECK_CONDITION;
288 status = SAM_STAT_GOOD;
290 target_complete_cmd(cmd, status);
294 static void iblock_bio_done(struct bio *bio)
296 struct se_cmd *cmd = bio->bi_private;
297 struct iblock_req *ibr = cmd->priv;
300 pr_err("bio error: %p, err: %d\n", bio, bio->bi_error);
302 * Bump the ib_bio_err_cnt and release bio.
304 atomic_inc(&ibr->ib_bio_err_cnt);
305 smp_mb__after_atomic();
310 iblock_complete_cmd(cmd);
314 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
316 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
320 * Only allocate as many vector entries as the bio code allows us to,
321 * we'll loop later on until we have handled the whole request.
323 if (sg_num > BIO_MAX_PAGES)
324 sg_num = BIO_MAX_PAGES;
326 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
328 pr_err("Unable to allocate memory for bio\n");
332 bio->bi_bdev = ib_dev->ibd_bd;
333 bio->bi_private = cmd;
334 bio->bi_end_io = &iblock_bio_done;
335 bio->bi_iter.bi_sector = lba;
340 static void iblock_submit_bios(struct bio_list *list, int rw)
342 struct blk_plug plug;
345 blk_start_plug(&plug);
346 while ((bio = bio_list_pop(list)))
348 blk_finish_plug(&plug);
351 static void iblock_end_io_flush(struct bio *bio)
353 struct se_cmd *cmd = bio->bi_private;
356 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error);
360 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
362 target_complete_cmd(cmd, SAM_STAT_GOOD);
369 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
370 * always flush the whole cache.
372 static sense_reason_t
373 iblock_execute_sync_cache(struct se_cmd *cmd)
375 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
376 int immed = (cmd->t_task_cdb[1] & 0x2);
380 * If the Immediate bit is set, queue up the GOOD response
381 * for this SYNCHRONIZE_CACHE op.
384 target_complete_cmd(cmd, SAM_STAT_GOOD);
386 bio = bio_alloc(GFP_KERNEL, 0);
387 bio->bi_end_io = iblock_end_io_flush;
388 bio->bi_bdev = ib_dev->ibd_bd;
390 bio->bi_private = cmd;
391 submit_bio(WRITE_FLUSH, bio);
395 static sense_reason_t
396 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
398 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
399 struct se_device *dev = cmd->se_dev;
402 ret = blkdev_issue_discard(bdev,
403 target_to_linux_sector(dev, lba),
404 target_to_linux_sector(dev, nolb),
407 pr_err("blkdev_issue_discard() failed: %d\n", ret);
408 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
414 static sense_reason_t
415 iblock_execute_write_same(struct se_cmd *cmd)
417 struct iblock_req *ibr;
418 struct scatterlist *sg;
420 struct bio_list list;
421 struct se_device *dev = cmd->se_dev;
422 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
423 sector_t sectors = target_to_linux_sector(dev,
424 sbc_get_write_same_sectors(cmd));
427 pr_err("WRITE_SAME: Protection information with IBLOCK"
428 " backends not supported\n");
429 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
431 sg = &cmd->t_data_sg[0];
433 if (cmd->t_data_nents > 1 ||
434 sg->length != cmd->se_dev->dev_attrib.block_size) {
435 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
436 " block_size: %u\n", cmd->t_data_nents, sg->length,
437 cmd->se_dev->dev_attrib.block_size);
438 return TCM_INVALID_CDB_FIELD;
441 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
446 bio = iblock_get_bio(cmd, block_lba, 1);
450 bio_list_init(&list);
451 bio_list_add(&list, bio);
453 atomic_set(&ibr->pending, 1);
456 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
459 bio = iblock_get_bio(cmd, block_lba, 1);
463 atomic_inc(&ibr->pending);
464 bio_list_add(&list, bio);
467 /* Always in 512 byte units for Linux/Block */
468 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
472 iblock_submit_bios(&list, WRITE);
476 while ((bio = bio_list_pop(&list)))
481 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
485 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
488 static match_table_t tokens = {
489 {Opt_udev_path, "udev_path=%s"},
490 {Opt_readonly, "readonly=%d"},
491 {Opt_force, "force=%d"},
495 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
496 const char *page, ssize_t count)
498 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
499 char *orig, *ptr, *arg_p, *opts;
500 substring_t args[MAX_OPT_ARGS];
502 unsigned long tmp_readonly;
504 opts = kstrdup(page, GFP_KERNEL);
510 while ((ptr = strsep(&opts, ",\n")) != NULL) {
514 token = match_token(ptr, tokens, args);
517 if (ib_dev->ibd_bd) {
518 pr_err("Unable to set udev_path= while"
519 " ib_dev->ibd_bd exists\n");
523 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
524 SE_UDEV_PATH_LEN) == 0) {
528 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
529 ib_dev->ibd_udev_path);
530 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
533 arg_p = match_strdup(&args[0]);
538 ret = kstrtoul(arg_p, 0, &tmp_readonly);
541 pr_err("kstrtoul() failed for"
545 ib_dev->ibd_readonly = tmp_readonly;
546 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
557 return (!ret) ? count : ret;
560 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
562 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
563 struct block_device *bd = ib_dev->ibd_bd;
564 char buf[BDEVNAME_SIZE];
568 bl += sprintf(b + bl, "iBlock device: %s",
570 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
571 bl += sprintf(b + bl, " UDEV PATH: %s",
572 ib_dev->ibd_udev_path);
573 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
575 bl += sprintf(b + bl, " ");
577 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
578 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
579 "" : (bd->bd_holder == ib_dev) ?
580 "CLAIMED: IBLOCK" : "CLAIMED: OS");
582 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
589 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
591 struct se_device *dev = cmd->se_dev;
592 struct blk_integrity *bi;
593 struct bio_integrity_payload *bip;
594 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
595 struct scatterlist *sg;
598 bi = bdev_get_integrity(ib_dev->ibd_bd);
600 pr_err("Unable to locate bio_integrity\n");
604 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
606 pr_err("Unable to allocate bio_integrity_payload\n");
610 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
612 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
614 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
615 (unsigned long long)bip->bip_iter.bi_sector);
617 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
619 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
621 if (rc != sg->length) {
622 pr_err("bio_integrity_add_page() failed; %d\n", rc);
626 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
627 sg_page(sg), sg->length, sg->offset);
633 static sense_reason_t
634 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
635 enum dma_data_direction data_direction)
637 struct se_device *dev = cmd->se_dev;
638 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
639 struct iblock_req *ibr;
640 struct bio *bio, *bio_start;
641 struct bio_list list;
642 struct scatterlist *sg;
643 u32 sg_num = sgl_nents;
648 if (data_direction == DMA_TO_DEVICE) {
649 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
650 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
652 * Force writethrough using WRITE_FUA if a volatile write cache
653 * is not enabled, or if initiator set the Force Unit Access bit.
655 if (q->flush_flags & REQ_FUA) {
656 if (cmd->se_cmd_flags & SCF_FUA)
658 else if (!(q->flush_flags & REQ_FLUSH))
669 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
675 atomic_set(&ibr->pending, 1);
676 iblock_complete_cmd(cmd);
680 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
685 bio_list_init(&list);
686 bio_list_add(&list, bio);
688 atomic_set(&ibr->pending, 2);
691 for_each_sg(sgl, sg, sgl_nents, i) {
693 * XXX: if the length the device accepts is shorter than the
694 * length of the S/G list entry this will cause and
695 * endless loop. Better hope no driver uses huge pages.
697 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
699 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
700 iblock_submit_bios(&list, rw);
704 bio = iblock_get_bio(cmd, block_lba, sg_num);
708 atomic_inc(&ibr->pending);
709 bio_list_add(&list, bio);
713 /* Always in 512 byte units for Linux/Block */
714 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
718 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
719 int rc = iblock_alloc_bip(cmd, bio_start);
724 iblock_submit_bios(&list, rw);
725 iblock_complete_cmd(cmd);
729 while ((bio = bio_list_pop(&list)))
734 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
737 static sector_t iblock_get_blocks(struct se_device *dev)
739 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
740 struct block_device *bd = ib_dev->ibd_bd;
741 struct request_queue *q = bdev_get_queue(bd);
743 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
746 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
748 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
749 struct block_device *bd = ib_dev->ibd_bd;
752 ret = bdev_alignment_offset(bd);
756 /* convert offset-bytes to offset-lbas */
757 return ret / bdev_logical_block_size(bd);
760 static unsigned int iblock_get_lbppbe(struct se_device *dev)
762 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
763 struct block_device *bd = ib_dev->ibd_bd;
764 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
766 return ilog2(logs_per_phys);
769 static unsigned int iblock_get_io_min(struct se_device *dev)
771 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
772 struct block_device *bd = ib_dev->ibd_bd;
774 return bdev_io_min(bd);
777 static unsigned int iblock_get_io_opt(struct se_device *dev)
779 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
780 struct block_device *bd = ib_dev->ibd_bd;
782 return bdev_io_opt(bd);
785 static struct sbc_ops iblock_sbc_ops = {
786 .execute_rw = iblock_execute_rw,
787 .execute_sync_cache = iblock_execute_sync_cache,
788 .execute_write_same = iblock_execute_write_same,
789 .execute_unmap = iblock_execute_unmap,
792 static sense_reason_t
793 iblock_parse_cdb(struct se_cmd *cmd)
795 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
798 static bool iblock_get_write_cache(struct se_device *dev)
800 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
801 struct block_device *bd = ib_dev->ibd_bd;
802 struct request_queue *q = bdev_get_queue(bd);
804 return q->flush_flags & REQ_FLUSH;
807 static const struct target_backend_ops iblock_ops = {
809 .inquiry_prod = "IBLOCK",
810 .inquiry_rev = IBLOCK_VERSION,
811 .owner = THIS_MODULE,
812 .attach_hba = iblock_attach_hba,
813 .detach_hba = iblock_detach_hba,
814 .alloc_device = iblock_alloc_device,
815 .configure_device = iblock_configure_device,
816 .free_device = iblock_free_device,
817 .parse_cdb = iblock_parse_cdb,
818 .set_configfs_dev_params = iblock_set_configfs_dev_params,
819 .show_configfs_dev_params = iblock_show_configfs_dev_params,
820 .get_device_type = sbc_get_device_type,
821 .get_blocks = iblock_get_blocks,
822 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
823 .get_lbppbe = iblock_get_lbppbe,
824 .get_io_min = iblock_get_io_min,
825 .get_io_opt = iblock_get_io_opt,
826 .get_write_cache = iblock_get_write_cache,
827 .tb_dev_attrib_attrs = sbc_attrib_attrs,
830 static int __init iblock_module_init(void)
832 return transport_backend_register(&iblock_ops);
835 static void __exit iblock_module_exit(void)
837 target_backend_unregister(&iblock_ops);
840 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
841 MODULE_AUTHOR("nab@Linux-iSCSI.org");
842 MODULE_LICENSE("GPL");
844 module_init(iblock_module_init);
845 module_exit(iblock_module_exit);