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 dev->dev_attrib.hw_block_size))
126 pr_debug("IBLOCK: BLOCK Discard support available,"
127 " disabled by default\n");
130 * Enable write same emulation for IBLOCK and use 0xFFFF as
131 * the smaller WRITE_SAME(10) only has a two-byte block count.
133 dev->dev_attrib.max_write_same_len = 0xFFFF;
135 if (blk_queue_nonrot(q))
136 dev->dev_attrib.is_nonrot = 1;
138 bi = bdev_get_integrity(bd);
140 struct bio_set *bs = ib_dev->ibd_bio_set;
142 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
143 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
144 pr_err("IBLOCK export of blk_integrity: %s not"
145 " supported\n", bi->profile->name);
150 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
151 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
152 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
153 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
156 if (dev->dev_attrib.pi_prot_type) {
157 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
158 pr_err("Unable to allocate bioset for PI\n");
162 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
163 bs->bio_integrity_pool);
165 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
171 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
173 bioset_free(ib_dev->ibd_bio_set);
174 ib_dev->ibd_bio_set = NULL;
179 static void iblock_dev_call_rcu(struct rcu_head *p)
181 struct se_device *dev = container_of(p, struct se_device, rcu_head);
182 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
187 static void iblock_free_device(struct se_device *dev)
189 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
191 if (ib_dev->ibd_bd != NULL)
192 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
193 if (ib_dev->ibd_bio_set != NULL)
194 bioset_free(ib_dev->ibd_bio_set);
196 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
199 static unsigned long long iblock_emulate_read_cap_with_block_size(
200 struct se_device *dev,
201 struct block_device *bd,
202 struct request_queue *q)
204 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
205 bdev_logical_block_size(bd)) - 1);
206 u32 block_size = bdev_logical_block_size(bd);
208 if (block_size == dev->dev_attrib.block_size)
211 switch (block_size) {
213 switch (dev->dev_attrib.block_size) {
227 switch (dev->dev_attrib.block_size) {
242 switch (dev->dev_attrib.block_size) {
257 switch (dev->dev_attrib.block_size) {
278 static void iblock_complete_cmd(struct se_cmd *cmd)
280 struct iblock_req *ibr = cmd->priv;
283 if (!atomic_dec_and_test(&ibr->pending))
286 if (atomic_read(&ibr->ib_bio_err_cnt))
287 status = SAM_STAT_CHECK_CONDITION;
289 status = SAM_STAT_GOOD;
291 target_complete_cmd(cmd, status);
295 static void iblock_bio_done(struct bio *bio)
297 struct se_cmd *cmd = bio->bi_private;
298 struct iblock_req *ibr = cmd->priv;
301 pr_err("bio error: %p, err: %d\n", bio, bio->bi_error);
303 * Bump the ib_bio_err_cnt and release bio.
305 atomic_inc(&ibr->ib_bio_err_cnt);
306 smp_mb__after_atomic();
311 iblock_complete_cmd(cmd);
315 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
318 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
322 * Only allocate as many vector entries as the bio code allows us to,
323 * we'll loop later on until we have handled the whole request.
325 if (sg_num > BIO_MAX_PAGES)
326 sg_num = BIO_MAX_PAGES;
328 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
330 pr_err("Unable to allocate memory for bio\n");
334 bio->bi_bdev = ib_dev->ibd_bd;
335 bio->bi_private = cmd;
336 bio->bi_end_io = &iblock_bio_done;
337 bio->bi_iter.bi_sector = lba;
338 bio_set_op_attrs(bio, op, op_flags);
343 static void iblock_submit_bios(struct bio_list *list)
345 struct blk_plug plug;
348 blk_start_plug(&plug);
349 while ((bio = bio_list_pop(list)))
351 blk_finish_plug(&plug);
354 static void iblock_end_io_flush(struct bio *bio)
356 struct se_cmd *cmd = bio->bi_private;
359 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error);
363 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
365 target_complete_cmd(cmd, SAM_STAT_GOOD);
372 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
373 * always flush the whole cache.
375 static sense_reason_t
376 iblock_execute_sync_cache(struct se_cmd *cmd)
378 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
379 int immed = (cmd->t_task_cdb[1] & 0x2);
383 * If the Immediate bit is set, queue up the GOOD response
384 * for this SYNCHRONIZE_CACHE op.
387 target_complete_cmd(cmd, SAM_STAT_GOOD);
389 bio = bio_alloc(GFP_KERNEL, 0);
390 bio->bi_end_io = iblock_end_io_flush;
391 bio->bi_bdev = ib_dev->ibd_bd;
392 bio->bi_rw = WRITE_FLUSH;
394 bio->bi_private = cmd;
399 static sense_reason_t
400 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
402 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
403 struct se_device *dev = cmd->se_dev;
406 ret = blkdev_issue_discard(bdev,
407 target_to_linux_sector(dev, lba),
408 target_to_linux_sector(dev, nolb),
411 pr_err("blkdev_issue_discard() failed: %d\n", ret);
412 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
418 static sense_reason_t
419 iblock_execute_write_same_direct(struct block_device *bdev, struct se_cmd *cmd)
421 struct se_device *dev = cmd->se_dev;
422 struct scatterlist *sg = &cmd->t_data_sg[0];
423 struct page *page = NULL;
427 page = alloc_page(GFP_KERNEL);
429 return TCM_OUT_OF_RESOURCES;
430 sg_copy_to_buffer(sg, cmd->t_data_nents, page_address(page),
431 dev->dev_attrib.block_size);
434 ret = blkdev_issue_write_same(bdev,
435 target_to_linux_sector(dev, cmd->t_task_lba),
436 target_to_linux_sector(dev,
437 sbc_get_write_same_sectors(cmd)),
438 GFP_KERNEL, page ? page : sg_page(sg));
442 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
444 target_complete_cmd(cmd, GOOD);
448 static sense_reason_t
449 iblock_execute_write_same(struct se_cmd *cmd)
451 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
452 struct iblock_req *ibr;
453 struct scatterlist *sg;
455 struct bio_list list;
456 struct se_device *dev = cmd->se_dev;
457 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
458 sector_t sectors = target_to_linux_sector(dev,
459 sbc_get_write_same_sectors(cmd));
462 pr_err("WRITE_SAME: Protection information with IBLOCK"
463 " backends not supported\n");
464 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
466 sg = &cmd->t_data_sg[0];
468 if (cmd->t_data_nents > 1 ||
469 sg->length != cmd->se_dev->dev_attrib.block_size) {
470 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
471 " block_size: %u\n", cmd->t_data_nents, sg->length,
472 cmd->se_dev->dev_attrib.block_size);
473 return TCM_INVALID_CDB_FIELD;
476 if (bdev_write_same(bdev))
477 return iblock_execute_write_same_direct(bdev, cmd);
479 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
484 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0);
488 bio_list_init(&list);
489 bio_list_add(&list, bio);
491 atomic_set(&ibr->pending, 1);
494 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
497 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE,
502 atomic_inc(&ibr->pending);
503 bio_list_add(&list, bio);
506 /* Always in 512 byte units for Linux/Block */
507 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
511 iblock_submit_bios(&list);
515 while ((bio = bio_list_pop(&list)))
520 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
524 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
527 static match_table_t tokens = {
528 {Opt_udev_path, "udev_path=%s"},
529 {Opt_readonly, "readonly=%d"},
530 {Opt_force, "force=%d"},
534 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
535 const char *page, ssize_t count)
537 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
538 char *orig, *ptr, *arg_p, *opts;
539 substring_t args[MAX_OPT_ARGS];
541 unsigned long tmp_readonly;
543 opts = kstrdup(page, GFP_KERNEL);
549 while ((ptr = strsep(&opts, ",\n")) != NULL) {
553 token = match_token(ptr, tokens, args);
556 if (ib_dev->ibd_bd) {
557 pr_err("Unable to set udev_path= while"
558 " ib_dev->ibd_bd exists\n");
562 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
563 SE_UDEV_PATH_LEN) == 0) {
567 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
568 ib_dev->ibd_udev_path);
569 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
572 arg_p = match_strdup(&args[0]);
577 ret = kstrtoul(arg_p, 0, &tmp_readonly);
580 pr_err("kstrtoul() failed for"
584 ib_dev->ibd_readonly = tmp_readonly;
585 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
596 return (!ret) ? count : ret;
599 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
601 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
602 struct block_device *bd = ib_dev->ibd_bd;
603 char buf[BDEVNAME_SIZE];
607 bl += sprintf(b + bl, "iBlock device: %s",
609 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
610 bl += sprintf(b + bl, " UDEV PATH: %s",
611 ib_dev->ibd_udev_path);
612 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
614 bl += sprintf(b + bl, " ");
616 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
617 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
618 "" : (bd->bd_holder == ib_dev) ?
619 "CLAIMED: IBLOCK" : "CLAIMED: OS");
621 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
628 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
630 struct se_device *dev = cmd->se_dev;
631 struct blk_integrity *bi;
632 struct bio_integrity_payload *bip;
633 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
634 struct scatterlist *sg;
637 bi = bdev_get_integrity(ib_dev->ibd_bd);
639 pr_err("Unable to locate bio_integrity\n");
643 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
645 pr_err("Unable to allocate bio_integrity_payload\n");
649 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
651 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
653 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
654 (unsigned long long)bip->bip_iter.bi_sector);
656 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
658 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
660 if (rc != sg->length) {
661 pr_err("bio_integrity_add_page() failed; %d\n", rc);
665 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
666 sg_page(sg), sg->length, sg->offset);
672 static sense_reason_t
673 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
674 enum dma_data_direction data_direction)
676 struct se_device *dev = cmd->se_dev;
677 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
678 struct iblock_req *ibr;
679 struct bio *bio, *bio_start;
680 struct bio_list list;
681 struct scatterlist *sg;
682 u32 sg_num = sgl_nents;
684 int i, op, op_flags = 0;
686 if (data_direction == DMA_TO_DEVICE) {
687 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
688 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
690 * Force writethrough using WRITE_FUA if a volatile write cache
691 * is not enabled, or if initiator set the Force Unit Access bit.
694 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
695 if (cmd->se_cmd_flags & SCF_FUA)
696 op_flags = WRITE_FUA;
697 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
698 op_flags = WRITE_FUA;
704 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
710 atomic_set(&ibr->pending, 1);
711 iblock_complete_cmd(cmd);
715 bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
720 bio_list_init(&list);
721 bio_list_add(&list, bio);
723 atomic_set(&ibr->pending, 2);
726 for_each_sg(sgl, sg, sgl_nents, i) {
728 * XXX: if the length the device accepts is shorter than the
729 * length of the S/G list entry this will cause and
730 * endless loop. Better hope no driver uses huge pages.
732 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
734 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
735 iblock_submit_bios(&list);
739 bio = iblock_get_bio(cmd, block_lba, sg_num, op,
744 atomic_inc(&ibr->pending);
745 bio_list_add(&list, bio);
749 /* Always in 512 byte units for Linux/Block */
750 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
754 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
755 int rc = iblock_alloc_bip(cmd, bio_start);
760 iblock_submit_bios(&list);
761 iblock_complete_cmd(cmd);
765 while ((bio = bio_list_pop(&list)))
770 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
773 static sector_t iblock_get_blocks(struct se_device *dev)
775 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
776 struct block_device *bd = ib_dev->ibd_bd;
777 struct request_queue *q = bdev_get_queue(bd);
779 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
782 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
784 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
785 struct block_device *bd = ib_dev->ibd_bd;
788 ret = bdev_alignment_offset(bd);
792 /* convert offset-bytes to offset-lbas */
793 return ret / bdev_logical_block_size(bd);
796 static unsigned int iblock_get_lbppbe(struct se_device *dev)
798 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
799 struct block_device *bd = ib_dev->ibd_bd;
800 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
802 return ilog2(logs_per_phys);
805 static unsigned int iblock_get_io_min(struct se_device *dev)
807 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
808 struct block_device *bd = ib_dev->ibd_bd;
810 return bdev_io_min(bd);
813 static unsigned int iblock_get_io_opt(struct se_device *dev)
815 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
816 struct block_device *bd = ib_dev->ibd_bd;
818 return bdev_io_opt(bd);
821 static struct sbc_ops iblock_sbc_ops = {
822 .execute_rw = iblock_execute_rw,
823 .execute_sync_cache = iblock_execute_sync_cache,
824 .execute_write_same = iblock_execute_write_same,
825 .execute_unmap = iblock_execute_unmap,
828 static sense_reason_t
829 iblock_parse_cdb(struct se_cmd *cmd)
831 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
834 static bool iblock_get_write_cache(struct se_device *dev)
836 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
837 struct block_device *bd = ib_dev->ibd_bd;
838 struct request_queue *q = bdev_get_queue(bd);
840 return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
843 static const struct target_backend_ops iblock_ops = {
845 .inquiry_prod = "IBLOCK",
846 .inquiry_rev = IBLOCK_VERSION,
847 .owner = THIS_MODULE,
848 .attach_hba = iblock_attach_hba,
849 .detach_hba = iblock_detach_hba,
850 .alloc_device = iblock_alloc_device,
851 .configure_device = iblock_configure_device,
852 .free_device = iblock_free_device,
853 .parse_cdb = iblock_parse_cdb,
854 .set_configfs_dev_params = iblock_set_configfs_dev_params,
855 .show_configfs_dev_params = iblock_show_configfs_dev_params,
856 .get_device_type = sbc_get_device_type,
857 .get_blocks = iblock_get_blocks,
858 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
859 .get_lbppbe = iblock_get_lbppbe,
860 .get_io_min = iblock_get_io_min,
861 .get_io_opt = iblock_get_io_opt,
862 .get_write_cache = iblock_get_write_cache,
863 .tb_dev_attrib_attrs = sbc_attrib_attrs,
866 static int __init iblock_module_init(void)
868 return transport_backend_register(&iblock_ops);
871 static void __exit iblock_module_exit(void)
873 target_backend_unregister(&iblock_ops);
876 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
877 MODULE_AUTHOR("nab@Linux-iSCSI.org");
878 MODULE_LICENSE("GPL");
880 module_init(iblock_module_init);
881 module_exit(iblock_module_exit);