1 /*******************************************************************************
2 * Filename: target_core_iblock.c
4 * This file contains the Storage Engine <-> Linux BlockIO transport
7 * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
8 * Copyright (c) 2005, 2006, 2007 SBE, Inc.
9 * Copyright (c) 2007-2010 Rising Tide Systems
10 * Copyright (c) 2008-2010 Linux-iSCSI.org
12 * Nicholas A. Bellinger <nab@kernel.org>
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
28 ******************************************************************************/
30 #include <linux/string.h>
31 #include <linux/parser.h>
32 #include <linux/timer.h>
34 #include <linux/blkdev.h>
35 #include <linux/slab.h>
36 #include <linux/spinlock.h>
37 #include <linux/bio.h>
38 #include <linux/genhd.h>
39 #include <linux/file.h>
40 #include <linux/module.h>
41 #include <scsi/scsi.h>
42 #include <scsi/scsi_host.h>
43 #include <asm/unaligned.h>
45 #include <target/target_core_base.h>
46 #include <target/target_core_backend.h>
48 #include "target_core_iblock.h"
50 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
51 #define IBLOCK_BIO_POOL_SIZE 128
53 static struct se_subsystem_api iblock_template;
55 static void iblock_bio_done(struct bio *, int);
57 /* iblock_attach_hba(): (Part of se_subsystem_api_t template)
61 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
63 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
64 " Generic Target Core Stack %s\n", hba->hba_id,
65 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
69 static void iblock_detach_hba(struct se_hba *hba)
73 static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
75 struct iblock_dev *ib_dev = NULL;
77 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
79 pr_err("Unable to allocate struct iblock_dev\n");
83 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
88 static struct se_device *iblock_create_virtdevice(
90 struct se_subsystem_dev *se_dev,
93 struct iblock_dev *ib_dev = p;
94 struct se_device *dev;
95 struct se_dev_limits dev_limits;
96 struct block_device *bd = NULL;
97 struct request_queue *q;
98 struct queue_limits *limits;
104 pr_err("Unable to locate struct iblock_dev parameter\n");
107 memset(&dev_limits, 0, sizeof(struct se_dev_limits));
109 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
110 if (!ib_dev->ibd_bio_set) {
111 pr_err("IBLOCK: Unable to create bioset()\n");
112 return ERR_PTR(-ENOMEM);
114 pr_debug("IBLOCK: Created bio_set()\n");
116 * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
117 * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
119 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
120 ib_dev->ibd_udev_path);
122 mode = FMODE_READ|FMODE_EXCL;
123 if (!ib_dev->ibd_readonly)
126 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
132 * Setup the local scope queue_limits from struct request_queue->limits
133 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
135 q = bdev_get_queue(bd);
136 limits = &dev_limits.limits;
137 limits->logical_block_size = bdev_logical_block_size(bd);
138 limits->max_hw_sectors = UINT_MAX;
139 limits->max_sectors = UINT_MAX;
140 dev_limits.hw_queue_depth = q->nr_requests;
141 dev_limits.queue_depth = q->nr_requests;
145 dev = transport_add_device_to_core_hba(hba,
146 &iblock_template, se_dev, dev_flags, ib_dev,
147 &dev_limits, "IBLOCK", IBLOCK_VERSION);
152 * Check if the underlying struct block_device request_queue supports
153 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
154 * in ATA and we need to set TPE=1
156 if (blk_queue_discard(q)) {
157 dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count =
158 q->limits.max_discard_sectors;
160 * Currently hardcoded to 1 in Linux/SCSI code..
162 dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count = 1;
163 dev->se_sub_dev->se_dev_attrib.unmap_granularity =
164 q->limits.discard_granularity >> 9;
165 dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment =
166 q->limits.discard_alignment;
168 pr_debug("IBLOCK: BLOCK Discard support available,"
169 " disabled by default\n");
172 if (blk_queue_nonrot(q))
173 dev->se_sub_dev->se_dev_attrib.is_nonrot = 1;
178 if (ib_dev->ibd_bio_set) {
179 bioset_free(ib_dev->ibd_bio_set);
180 ib_dev->ibd_bio_set = NULL;
182 ib_dev->ibd_bd = NULL;
186 static void iblock_free_device(void *p)
188 struct iblock_dev *ib_dev = p;
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);
197 static unsigned long long iblock_emulate_read_cap_with_block_size(
198 struct se_device *dev,
199 struct block_device *bd,
200 struct request_queue *q)
202 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
203 bdev_logical_block_size(bd)) - 1);
204 u32 block_size = bdev_logical_block_size(bd);
206 if (block_size == dev->se_sub_dev->se_dev_attrib.block_size)
209 switch (block_size) {
211 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
225 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
240 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
255 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
276 static void iblock_end_io_flush(struct bio *bio, int err)
278 struct se_cmd *cmd = bio->bi_private;
281 pr_err("IBLOCK: cache flush failed: %d\n", err);
285 cmd->scsi_sense_reason =
286 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
287 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
289 target_complete_cmd(cmd, SAM_STAT_GOOD);
297 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
298 * always flush the whole cache.
300 static int iblock_execute_sync_cache(struct se_cmd *cmd)
302 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
303 int immed = (cmd->t_task_cdb[1] & 0x2);
307 * If the Immediate bit is set, queue up the GOOD response
308 * for this SYNCHRONIZE_CACHE op.
311 target_complete_cmd(cmd, SAM_STAT_GOOD);
313 bio = bio_alloc(GFP_KERNEL, 0);
314 bio->bi_end_io = iblock_end_io_flush;
315 bio->bi_bdev = ib_dev->ibd_bd;
317 bio->bi_private = cmd;
318 submit_bio(WRITE_FLUSH, bio);
322 static int iblock_execute_unmap(struct se_cmd *cmd)
324 struct se_device *dev = cmd->se_dev;
325 struct iblock_dev *ibd = dev->dev_ptr;
326 unsigned char *buf, *ptr = NULL;
333 if (cmd->data_length < 8) {
334 pr_warn("UNMAP parameter list length %u too small\n",
336 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
340 buf = transport_kmap_data_sg(cmd);
342 dl = get_unaligned_be16(&buf[0]);
343 bd_dl = get_unaligned_be16(&buf[2]);
345 size = cmd->data_length - 8;
347 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
348 cmd->data_length, bd_dl);
352 if (size / 16 > dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count) {
353 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
358 /* First UNMAP block descriptor starts at 8 byte offset */
360 pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
361 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
364 lba = get_unaligned_be64(&ptr[0]);
365 range = get_unaligned_be32(&ptr[8]);
366 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
367 (unsigned long long)lba, range);
369 if (range > dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count) {
370 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
375 if (lba + range > dev->transport->get_blocks(dev) + 1) {
376 cmd->scsi_sense_reason = TCM_ADDRESS_OUT_OF_RANGE;
381 ret = blkdev_issue_discard(ibd->ibd_bd, lba, range,
384 pr_err("blkdev_issue_discard() failed: %d\n",
394 transport_kunmap_data_sg(cmd);
396 target_complete_cmd(cmd, GOOD);
400 static int iblock_execute_write_same(struct se_cmd *cmd)
402 struct iblock_dev *ibd = cmd->se_dev->dev_ptr;
405 ret = blkdev_issue_discard(ibd->ibd_bd, cmd->t_task_lba,
406 spc_get_write_same_sectors(cmd), GFP_KERNEL,
409 pr_debug("blkdev_issue_discard() failed for WRITE_SAME\n");
413 target_complete_cmd(cmd, GOOD);
418 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
421 static match_table_t tokens = {
422 {Opt_udev_path, "udev_path=%s"},
423 {Opt_readonly, "readonly=%d"},
424 {Opt_force, "force=%d"},
428 static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
429 struct se_subsystem_dev *se_dev,
430 const char *page, ssize_t count)
432 struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
433 char *orig, *ptr, *arg_p, *opts;
434 substring_t args[MAX_OPT_ARGS];
436 unsigned long tmp_readonly;
438 opts = kstrdup(page, GFP_KERNEL);
444 while ((ptr = strsep(&opts, ",\n")) != NULL) {
448 token = match_token(ptr, tokens, args);
451 if (ib_dev->ibd_bd) {
452 pr_err("Unable to set udev_path= while"
453 " ib_dev->ibd_bd exists\n");
457 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
458 SE_UDEV_PATH_LEN) == 0) {
462 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
463 ib_dev->ibd_udev_path);
464 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
467 arg_p = match_strdup(&args[0]);
472 ret = strict_strtoul(arg_p, 0, &tmp_readonly);
475 pr_err("strict_strtoul() failed for"
479 ib_dev->ibd_readonly = tmp_readonly;
480 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
491 return (!ret) ? count : ret;
494 static ssize_t iblock_check_configfs_dev_params(
496 struct se_subsystem_dev *se_dev)
498 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
500 if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
501 pr_err("Missing udev_path= parameters for IBLOCK\n");
508 static ssize_t iblock_show_configfs_dev_params(
510 struct se_subsystem_dev *se_dev,
513 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
514 struct block_device *bd = ibd->ibd_bd;
515 char buf[BDEVNAME_SIZE];
519 bl += sprintf(b + bl, "iBlock device: %s",
521 if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH)
522 bl += sprintf(b + bl, " UDEV PATH: %s",
524 bl += sprintf(b + bl, " readonly: %d\n", ibd->ibd_readonly);
526 bl += sprintf(b + bl, " ");
528 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
529 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
530 "" : (bd->bd_holder == ibd) ?
531 "CLAIMED: IBLOCK" : "CLAIMED: OS");
533 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
539 static void iblock_complete_cmd(struct se_cmd *cmd)
541 struct iblock_req *ibr = cmd->priv;
544 if (!atomic_dec_and_test(&ibr->pending))
547 if (atomic_read(&ibr->ib_bio_err_cnt))
548 status = SAM_STAT_CHECK_CONDITION;
550 status = SAM_STAT_GOOD;
552 target_complete_cmd(cmd, status);
557 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
559 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
563 * Only allocate as many vector entries as the bio code allows us to,
564 * we'll loop later on until we have handled the whole request.
566 if (sg_num > BIO_MAX_PAGES)
567 sg_num = BIO_MAX_PAGES;
569 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
571 pr_err("Unable to allocate memory for bio\n");
575 bio->bi_bdev = ib_dev->ibd_bd;
576 bio->bi_private = cmd;
577 bio->bi_end_io = &iblock_bio_done;
578 bio->bi_sector = lba;
582 static void iblock_submit_bios(struct bio_list *list, int rw)
584 struct blk_plug plug;
587 blk_start_plug(&plug);
588 while ((bio = bio_list_pop(list)))
590 blk_finish_plug(&plug);
593 static int iblock_execute_rw(struct se_cmd *cmd)
595 struct scatterlist *sgl = cmd->t_data_sg;
596 u32 sgl_nents = cmd->t_data_nents;
597 enum dma_data_direction data_direction = cmd->data_direction;
598 struct se_device *dev = cmd->se_dev;
599 struct iblock_req *ibr;
601 struct bio_list list;
602 struct scatterlist *sg;
603 u32 sg_num = sgl_nents;
609 if (data_direction == DMA_TO_DEVICE) {
611 * Force data to disk if we pretend to not have a volatile
612 * write cache, or the initiator set the Force Unit Access bit.
614 if (dev->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 ||
615 (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
616 (cmd->se_cmd_flags & SCF_FUA)))
625 * Convert the blocksize advertised to the initiator to the 512 byte
626 * units unconditionally used by the Linux block layer.
628 if (dev->se_sub_dev->se_dev_attrib.block_size == 4096)
629 block_lba = (cmd->t_task_lba << 3);
630 else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048)
631 block_lba = (cmd->t_task_lba << 2);
632 else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024)
633 block_lba = (cmd->t_task_lba << 1);
634 else if (dev->se_sub_dev->se_dev_attrib.block_size == 512)
635 block_lba = cmd->t_task_lba;
637 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
638 " %u\n", dev->se_sub_dev->se_dev_attrib.block_size);
639 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
643 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
649 atomic_set(&ibr->pending, 1);
650 iblock_complete_cmd(cmd);
654 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
658 bio_list_init(&list);
659 bio_list_add(&list, bio);
661 atomic_set(&ibr->pending, 2);
664 for_each_sg(sgl, sg, sgl_nents, i) {
666 * XXX: if the length the device accepts is shorter than the
667 * length of the S/G list entry this will cause and
668 * endless loop. Better hope no driver uses huge pages.
670 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
672 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
673 iblock_submit_bios(&list, rw);
677 bio = iblock_get_bio(cmd, block_lba, sg_num);
681 atomic_inc(&ibr->pending);
682 bio_list_add(&list, bio);
686 /* Always in 512 byte units for Linux/Block */
687 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
691 iblock_submit_bios(&list, rw);
692 iblock_complete_cmd(cmd);
696 while ((bio = bio_list_pop(&list)))
700 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
705 static u32 iblock_get_device_rev(struct se_device *dev)
707 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
710 static u32 iblock_get_device_type(struct se_device *dev)
715 static sector_t iblock_get_blocks(struct se_device *dev)
717 struct iblock_dev *ibd = dev->dev_ptr;
718 struct block_device *bd = ibd->ibd_bd;
719 struct request_queue *q = bdev_get_queue(bd);
721 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
724 static void iblock_bio_done(struct bio *bio, int err)
726 struct se_cmd *cmd = bio->bi_private;
727 struct iblock_req *ibr = cmd->priv;
730 * Set -EIO if !BIO_UPTODATE and the passed is still err=0
732 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
736 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
737 " err: %d\n", bio, err);
739 * Bump the ib_bio_err_cnt and release bio.
741 atomic_inc(&ibr->ib_bio_err_cnt);
742 smp_mb__after_atomic_inc();
747 iblock_complete_cmd(cmd);
750 static struct spc_ops iblock_spc_ops = {
751 .execute_rw = iblock_execute_rw,
752 .execute_sync_cache = iblock_execute_sync_cache,
753 .execute_write_same = iblock_execute_write_same,
754 .execute_unmap = iblock_execute_unmap,
757 static int iblock_parse_cdb(struct se_cmd *cmd)
759 return sbc_parse_cdb(cmd, &iblock_spc_ops);
762 static struct se_subsystem_api iblock_template = {
764 .owner = THIS_MODULE,
765 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
766 .attach_hba = iblock_attach_hba,
767 .detach_hba = iblock_detach_hba,
768 .allocate_virtdevice = iblock_allocate_virtdevice,
769 .create_virtdevice = iblock_create_virtdevice,
770 .free_device = iblock_free_device,
771 .parse_cdb = iblock_parse_cdb,
772 .check_configfs_dev_params = iblock_check_configfs_dev_params,
773 .set_configfs_dev_params = iblock_set_configfs_dev_params,
774 .show_configfs_dev_params = iblock_show_configfs_dev_params,
775 .get_device_rev = iblock_get_device_rev,
776 .get_device_type = iblock_get_device_type,
777 .get_blocks = iblock_get_blocks,
780 static int __init iblock_module_init(void)
782 return transport_subsystem_register(&iblock_template);
785 static void iblock_module_exit(void)
787 transport_subsystem_release(&iblock_template);
790 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
791 MODULE_AUTHOR("nab@Linux-iSCSI.org");
792 MODULE_LICENSE("GPL");
794 module_init(iblock_module_init);
795 module_exit(iblock_module_exit);