Root/drivers/target/target_core_iblock.c

1/*******************************************************************************
2 * Filename: target_core_iblock.c
3 *
4 * This file contains the Storage Engine <-> Linux BlockIO transport
5 * specific functions.
6 *
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
11 *
12 * Nicholas A. Bellinger <nab@kernel.org>
13 *
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.
18 *
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.
23 *
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.
27 *
28 ******************************************************************************/
29
30#include <linux/string.h>
31#include <linux/parser.h>
32#include <linux/timer.h>
33#include <linux/fs.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>
44
45#include <target/target_core_base.h>
46#include <target/target_core_backend.h>
47
48#include "target_core_iblock.h"
49
50#define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
51#define IBLOCK_BIO_POOL_SIZE 128
52
53static struct se_subsystem_api iblock_template;
54
55static void iblock_bio_done(struct bio *, int);
56
57/* iblock_attach_hba(): (Part of se_subsystem_api_t template)
58 *
59 *
60 */
61static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
62{
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);
66    return 0;
67}
68
69static void iblock_detach_hba(struct se_hba *hba)
70{
71}
72
73static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
74{
75    struct iblock_dev *ib_dev = NULL;
76
77    ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
78    if (!ib_dev) {
79        pr_err("Unable to allocate struct iblock_dev\n");
80        return NULL;
81    }
82
83    pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
84
85    return ib_dev;
86}
87
88static struct se_device *iblock_create_virtdevice(
89    struct se_hba *hba,
90    struct se_subsystem_dev *se_dev,
91    void *p)
92{
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;
99    u32 dev_flags = 0;
100    fmode_t mode;
101    int ret = -EINVAL;
102
103    if (!ib_dev) {
104        pr_err("Unable to locate struct iblock_dev parameter\n");
105        return ERR_PTR(ret);
106    }
107    memset(&dev_limits, 0, sizeof(struct se_dev_limits));
108
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);
113    }
114    pr_debug("IBLOCK: Created bio_set()\n");
115    /*
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.
118     */
119    pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
120            ib_dev->ibd_udev_path);
121
122    mode = FMODE_READ|FMODE_EXCL;
123    if (!ib_dev->ibd_readonly)
124        mode |= FMODE_WRITE;
125
126    bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
127    if (IS_ERR(bd)) {
128        ret = PTR_ERR(bd);
129        goto failed;
130    }
131    /*
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.
134     */
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;
142
143    ib_dev->ibd_bd = bd;
144
145    dev = transport_add_device_to_core_hba(hba,
146            &iblock_template, se_dev, dev_flags, ib_dev,
147            &dev_limits, "IBLOCK", IBLOCK_VERSION);
148    if (!dev)
149        goto failed;
150
151    /*
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
155     */
156    if (blk_queue_discard(q)) {
157        dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count =
158                q->limits.max_discard_sectors;
159        /*
160         * Currently hardcoded to 1 in Linux/SCSI code..
161         */
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;
167
168        pr_debug("IBLOCK: BLOCK Discard support available,"
169                " disabled by default\n");
170    }
171
172    if (blk_queue_nonrot(q))
173        dev->se_sub_dev->se_dev_attrib.is_nonrot = 1;
174
175    return dev;
176
177failed:
178    if (ib_dev->ibd_bio_set) {
179        bioset_free(ib_dev->ibd_bio_set);
180        ib_dev->ibd_bio_set = NULL;
181    }
182    ib_dev->ibd_bd = NULL;
183    return ERR_PTR(ret);
184}
185
186static void iblock_free_device(void *p)
187{
188    struct iblock_dev *ib_dev = p;
189
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);
194    kfree(ib_dev);
195}
196
197static 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)
201{
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);
205
206    if (block_size == dev->se_sub_dev->se_dev_attrib.block_size)
207        return blocks_long;
208
209    switch (block_size) {
210    case 4096:
211        switch (dev->se_sub_dev->se_dev_attrib.block_size) {
212        case 2048:
213            blocks_long <<= 1;
214            break;
215        case 1024:
216            blocks_long <<= 2;
217            break;
218        case 512:
219            blocks_long <<= 3;
220        default:
221            break;
222        }
223        break;
224    case 2048:
225        switch (dev->se_sub_dev->se_dev_attrib.block_size) {
226        case 4096:
227            blocks_long >>= 1;
228            break;
229        case 1024:
230            blocks_long <<= 1;
231            break;
232        case 512:
233            blocks_long <<= 2;
234            break;
235        default:
236            break;
237        }
238        break;
239    case 1024:
240        switch (dev->se_sub_dev->se_dev_attrib.block_size) {
241        case 4096:
242            blocks_long >>= 2;
243            break;
244        case 2048:
245            blocks_long >>= 1;
246            break;
247        case 512:
248            blocks_long <<= 1;
249            break;
250        default:
251            break;
252        }
253        break;
254    case 512:
255        switch (dev->se_sub_dev->se_dev_attrib.block_size) {
256        case 4096:
257            blocks_long >>= 3;
258            break;
259        case 2048:
260            blocks_long >>= 2;
261            break;
262        case 1024:
263            blocks_long >>= 1;
264            break;
265        default:
266            break;
267        }
268        break;
269    default:
270        break;
271    }
272
273    return blocks_long;
274}
275
276static void iblock_end_io_flush(struct bio *bio, int err)
277{
278    struct se_cmd *cmd = bio->bi_private;
279
280    if (err)
281        pr_err("IBLOCK: cache flush failed: %d\n", err);
282
283    if (cmd) {
284        if (err) {
285            cmd->scsi_sense_reason =
286                TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
287            target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
288        } else {
289            target_complete_cmd(cmd, SAM_STAT_GOOD);
290        }
291    }
292
293    bio_put(bio);
294}
295
296/*
297 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
298 * always flush the whole cache.
299 */
300static int iblock_execute_sync_cache(struct se_cmd *cmd)
301{
302    struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
303    int immed = (cmd->t_task_cdb[1] & 0x2);
304    struct bio *bio;
305
306    /*
307     * If the Immediate bit is set, queue up the GOOD response
308     * for this SYNCHRONIZE_CACHE op.
309     */
310    if (immed)
311        target_complete_cmd(cmd, SAM_STAT_GOOD);
312
313    bio = bio_alloc(GFP_KERNEL, 0);
314    bio->bi_end_io = iblock_end_io_flush;
315    bio->bi_bdev = ib_dev->ibd_bd;
316    if (!immed)
317        bio->bi_private = cmd;
318    submit_bio(WRITE_FLUSH, bio);
319    return 0;
320}
321
322static int iblock_execute_unmap(struct se_cmd *cmd)
323{
324    struct se_device *dev = cmd->se_dev;
325    struct iblock_dev *ibd = dev->dev_ptr;
326    unsigned char *buf, *ptr = NULL;
327    sector_t lba;
328    int size;
329    u32 range;
330    int ret = 0;
331    int dl, bd_dl;
332
333    if (cmd->data_length < 8) {
334        pr_warn("UNMAP parameter list length %u too small\n",
335            cmd->data_length);
336        cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
337        return -EINVAL;
338    }
339
340    buf = transport_kmap_data_sg(cmd);
341
342    dl = get_unaligned_be16(&buf[0]);
343    bd_dl = get_unaligned_be16(&buf[2]);
344
345    size = cmd->data_length - 8;
346    if (bd_dl > size)
347        pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
348            cmd->data_length, bd_dl);
349    else
350        size = bd_dl;
351
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;
354        ret = -EINVAL;
355        goto err;
356    }
357
358    /* First UNMAP block descriptor starts at 8 byte offset */
359    ptr = &buf[8];
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);
362
363    while (size >= 16) {
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);
368
369        if (range > dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count) {
370            cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
371            ret = -EINVAL;
372            goto err;
373        }
374
375        if (lba + range > dev->transport->get_blocks(dev) + 1) {
376            cmd->scsi_sense_reason = TCM_ADDRESS_OUT_OF_RANGE;
377            ret = -EINVAL;
378            goto err;
379        }
380
381        ret = blkdev_issue_discard(ibd->ibd_bd, lba, range,
382                       GFP_KERNEL, 0);
383        if (ret < 0) {
384            pr_err("blkdev_issue_discard() failed: %d\n",
385                    ret);
386            goto err;
387        }
388
389        ptr += 16;
390        size -= 16;
391    }
392
393err:
394    transport_kunmap_data_sg(cmd);
395    if (!ret)
396        target_complete_cmd(cmd, GOOD);
397    return ret;
398}
399
400static int iblock_execute_write_same(struct se_cmd *cmd)
401{
402    struct iblock_dev *ibd = cmd->se_dev->dev_ptr;
403    int ret;
404
405    ret = blkdev_issue_discard(ibd->ibd_bd, cmd->t_task_lba,
406                   spc_get_write_same_sectors(cmd), GFP_KERNEL,
407                   0);
408    if (ret < 0) {
409        pr_debug("blkdev_issue_discard() failed for WRITE_SAME\n");
410        return ret;
411    }
412
413    target_complete_cmd(cmd, GOOD);
414    return 0;
415}
416
417enum {
418    Opt_udev_path, Opt_readonly, Opt_force, Opt_err
419};
420
421static match_table_t tokens = {
422    {Opt_udev_path, "udev_path=%s"},
423    {Opt_readonly, "readonly=%d"},
424    {Opt_force, "force=%d"},
425    {Opt_err, NULL}
426};
427
428static 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)
431{
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];
435    int ret = 0, token;
436    unsigned long tmp_readonly;
437
438    opts = kstrdup(page, GFP_KERNEL);
439    if (!opts)
440        return -ENOMEM;
441
442    orig = opts;
443
444    while ((ptr = strsep(&opts, ",\n")) != NULL) {
445        if (!*ptr)
446            continue;
447
448        token = match_token(ptr, tokens, args);
449        switch (token) {
450        case Opt_udev_path:
451            if (ib_dev->ibd_bd) {
452                pr_err("Unable to set udev_path= while"
453                    " ib_dev->ibd_bd exists\n");
454                ret = -EEXIST;
455                goto out;
456            }
457            arg_p = match_strdup(&args[0]);
458            if (!arg_p) {
459                ret = -ENOMEM;
460                break;
461            }
462            snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
463                    "%s", arg_p);
464            kfree(arg_p);
465            pr_debug("IBLOCK: Referencing UDEV path: %s\n",
466                    ib_dev->ibd_udev_path);
467            ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
468            break;
469        case Opt_readonly:
470            arg_p = match_strdup(&args[0]);
471            if (!arg_p) {
472                ret = -ENOMEM;
473                break;
474            }
475            ret = strict_strtoul(arg_p, 0, &tmp_readonly);
476            kfree(arg_p);
477            if (ret < 0) {
478                pr_err("strict_strtoul() failed for"
479                        " readonly=\n");
480                goto out;
481            }
482            ib_dev->ibd_readonly = tmp_readonly;
483            pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
484            break;
485        case Opt_force:
486            break;
487        default:
488            break;
489        }
490    }
491
492out:
493    kfree(orig);
494    return (!ret) ? count : ret;
495}
496
497static ssize_t iblock_check_configfs_dev_params(
498    struct se_hba *hba,
499    struct se_subsystem_dev *se_dev)
500{
501    struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
502
503    if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
504        pr_err("Missing udev_path= parameters for IBLOCK\n");
505        return -EINVAL;
506    }
507
508    return 0;
509}
510
511static ssize_t iblock_show_configfs_dev_params(
512    struct se_hba *hba,
513    struct se_subsystem_dev *se_dev,
514    char *b)
515{
516    struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
517    struct block_device *bd = ibd->ibd_bd;
518    char buf[BDEVNAME_SIZE];
519    ssize_t bl = 0;
520
521    if (bd)
522        bl += sprintf(b + bl, "iBlock device: %s",
523                bdevname(bd, buf));
524    if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH)
525        bl += sprintf(b + bl, " UDEV PATH: %s",
526                ibd->ibd_udev_path);
527    bl += sprintf(b + bl, " readonly: %d\n", ibd->ibd_readonly);
528
529    bl += sprintf(b + bl, " ");
530    if (bd) {
531        bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
532            MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
533            "" : (bd->bd_holder == ibd) ?
534            "CLAIMED: IBLOCK" : "CLAIMED: OS");
535    } else {
536        bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
537    }
538
539    return bl;
540}
541
542static void iblock_complete_cmd(struct se_cmd *cmd)
543{
544    struct iblock_req *ibr = cmd->priv;
545    u8 status;
546
547    if (!atomic_dec_and_test(&ibr->pending))
548        return;
549
550    if (atomic_read(&ibr->ib_bio_err_cnt))
551        status = SAM_STAT_CHECK_CONDITION;
552    else
553        status = SAM_STAT_GOOD;
554
555    target_complete_cmd(cmd, status);
556    kfree(ibr);
557}
558
559static void iblock_bio_destructor(struct bio *bio)
560{
561    struct se_cmd *cmd = bio->bi_private;
562    struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
563
564    bio_free(bio, ib_dev->ibd_bio_set);
565}
566
567static struct bio *
568iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
569{
570    struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
571    struct bio *bio;
572
573    /*
574     * Only allocate as many vector entries as the bio code allows us to,
575     * we'll loop later on until we have handled the whole request.
576     */
577    if (sg_num > BIO_MAX_PAGES)
578        sg_num = BIO_MAX_PAGES;
579
580    bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
581    if (!bio) {
582        pr_err("Unable to allocate memory for bio\n");
583        return NULL;
584    }
585
586    bio->bi_bdev = ib_dev->ibd_bd;
587    bio->bi_private = cmd;
588    bio->bi_destructor = iblock_bio_destructor;
589    bio->bi_end_io = &iblock_bio_done;
590    bio->bi_sector = lba;
591    return bio;
592}
593
594static void iblock_submit_bios(struct bio_list *list, int rw)
595{
596    struct blk_plug plug;
597    struct bio *bio;
598
599    blk_start_plug(&plug);
600    while ((bio = bio_list_pop(list)))
601        submit_bio(rw, bio);
602    blk_finish_plug(&plug);
603}
604
605static int iblock_execute_rw(struct se_cmd *cmd)
606{
607    struct scatterlist *sgl = cmd->t_data_sg;
608    u32 sgl_nents = cmd->t_data_nents;
609    enum dma_data_direction data_direction = cmd->data_direction;
610    struct se_device *dev = cmd->se_dev;
611    struct iblock_req *ibr;
612    struct bio *bio;
613    struct bio_list list;
614    struct scatterlist *sg;
615    u32 sg_num = sgl_nents;
616    sector_t block_lba;
617    unsigned bio_cnt;
618    int rw;
619    int i;
620
621    if (data_direction == DMA_TO_DEVICE) {
622        /*
623         * Force data to disk if we pretend to not have a volatile
624         * write cache, or the initiator set the Force Unit Access bit.
625         */
626        if (dev->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 ||
627            (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
628             (cmd->se_cmd_flags & SCF_FUA)))
629            rw = WRITE_FUA;
630        else
631            rw = WRITE;
632    } else {
633        rw = READ;
634    }
635
636    /*
637     * Convert the blocksize advertised to the initiator to the 512 byte
638     * units unconditionally used by the Linux block layer.
639     */
640    if (dev->se_sub_dev->se_dev_attrib.block_size == 4096)
641        block_lba = (cmd->t_task_lba << 3);
642    else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048)
643        block_lba = (cmd->t_task_lba << 2);
644    else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024)
645        block_lba = (cmd->t_task_lba << 1);
646    else if (dev->se_sub_dev->se_dev_attrib.block_size == 512)
647        block_lba = cmd->t_task_lba;
648    else {
649        pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
650                " %u\n", dev->se_sub_dev->se_dev_attrib.block_size);
651        cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
652        return -ENOSYS;
653    }
654
655    ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
656    if (!ibr)
657        goto fail;
658    cmd->priv = ibr;
659
660    bio = iblock_get_bio(cmd, block_lba, sgl_nents);
661    if (!bio)
662        goto fail_free_ibr;
663
664    bio_list_init(&list);
665    bio_list_add(&list, bio);
666
667    atomic_set(&ibr->pending, 2);
668    bio_cnt = 1;
669
670    for_each_sg(sgl, sg, sgl_nents, i) {
671        /*
672         * XXX: if the length the device accepts is shorter than the
673         * length of the S/G list entry this will cause and
674         * endless loop. Better hope no driver uses huge pages.
675         */
676        while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
677                != sg->length) {
678            if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
679                iblock_submit_bios(&list, rw);
680                bio_cnt = 0;
681            }
682
683            bio = iblock_get_bio(cmd, block_lba, sg_num);
684            if (!bio)
685                goto fail_put_bios;
686
687            atomic_inc(&ibr->pending);
688            bio_list_add(&list, bio);
689            bio_cnt++;
690        }
691
692        /* Always in 512 byte units for Linux/Block */
693        block_lba += sg->length >> IBLOCK_LBA_SHIFT;
694        sg_num--;
695    }
696
697    iblock_submit_bios(&list, rw);
698    iblock_complete_cmd(cmd);
699    return 0;
700
701fail_put_bios:
702    while ((bio = bio_list_pop(&list)))
703        bio_put(bio);
704fail_free_ibr:
705    kfree(ibr);
706    cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
707fail:
708    return -ENOMEM;
709}
710
711static u32 iblock_get_device_rev(struct se_device *dev)
712{
713    return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
714}
715
716static u32 iblock_get_device_type(struct se_device *dev)
717{
718    return TYPE_DISK;
719}
720
721static sector_t iblock_get_blocks(struct se_device *dev)
722{
723    struct iblock_dev *ibd = dev->dev_ptr;
724    struct block_device *bd = ibd->ibd_bd;
725    struct request_queue *q = bdev_get_queue(bd);
726
727    return iblock_emulate_read_cap_with_block_size(dev, bd, q);
728}
729
730static void iblock_bio_done(struct bio *bio, int err)
731{
732    struct se_cmd *cmd = bio->bi_private;
733    struct iblock_req *ibr = cmd->priv;
734
735    /*
736     * Set -EIO if !BIO_UPTODATE and the passed is still err=0
737     */
738    if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
739        err = -EIO;
740
741    if (err != 0) {
742        pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
743            " err: %d\n", bio, err);
744        /*
745         * Bump the ib_bio_err_cnt and release bio.
746         */
747        atomic_inc(&ibr->ib_bio_err_cnt);
748        smp_mb__after_atomic_inc();
749    }
750
751    bio_put(bio);
752
753    iblock_complete_cmd(cmd);
754}
755
756static struct spc_ops iblock_spc_ops = {
757    .execute_rw = iblock_execute_rw,
758    .execute_sync_cache = iblock_execute_sync_cache,
759    .execute_write_same = iblock_execute_write_same,
760    .execute_unmap = iblock_execute_unmap,
761};
762
763static int iblock_parse_cdb(struct se_cmd *cmd)
764{
765    return sbc_parse_cdb(cmd, &iblock_spc_ops);
766}
767
768static struct se_subsystem_api iblock_template = {
769    .name = "iblock",
770    .owner = THIS_MODULE,
771    .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
772    .write_cache_emulated = 1,
773    .fua_write_emulated = 1,
774    .attach_hba = iblock_attach_hba,
775    .detach_hba = iblock_detach_hba,
776    .allocate_virtdevice = iblock_allocate_virtdevice,
777    .create_virtdevice = iblock_create_virtdevice,
778    .free_device = iblock_free_device,
779    .parse_cdb = iblock_parse_cdb,
780    .check_configfs_dev_params = iblock_check_configfs_dev_params,
781    .set_configfs_dev_params = iblock_set_configfs_dev_params,
782    .show_configfs_dev_params = iblock_show_configfs_dev_params,
783    .get_device_rev = iblock_get_device_rev,
784    .get_device_type = iblock_get_device_type,
785    .get_blocks = iblock_get_blocks,
786};
787
788static int __init iblock_module_init(void)
789{
790    return transport_subsystem_register(&iblock_template);
791}
792
793static void iblock_module_exit(void)
794{
795    transport_subsystem_release(&iblock_template);
796}
797
798MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
799MODULE_AUTHOR("nab@Linux-iSCSI.org");
800MODULE_LICENSE("GPL");
801
802module_init(iblock_module_init);
803module_exit(iblock_module_exit);
804

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