swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 219d54332a09e8d8741c1e1982f5eae56099de85 authored by Linus Torvalds on 25 November 2019, 00:32:01 UTC
Linux 5.4
Linux 5.4
Tip revision: 219d543
target_core_iblock.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
* Filename: target_core_iblock.c
*
* This file contains the Storage Engine <-> Linux BlockIO transport
* specific functions.
*
* (c) Copyright 2003-2013 Datera, Inc.
*
* Nicholas A. Bellinger <nab@kernel.org>
*
******************************************************************************/
#include <linux/string.h>
#include <linux/parser.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/bio.h>
#include <linux/genhd.h>
#include <linux/file.h>
#include <linux/module.h>
#include <scsi/scsi_proto.h>
#include <asm/unaligned.h>
#include <target/target_core_base.h>
#include <target/target_core_backend.h>
#include "target_core_iblock.h"
#define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
#define IBLOCK_BIO_POOL_SIZE 128
static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
{
return container_of(dev, struct iblock_dev, dev);
}
static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
{
pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
" Generic Target Core Stack %s\n", hba->hba_id,
IBLOCK_VERSION, TARGET_CORE_VERSION);
return 0;
}
static void iblock_detach_hba(struct se_hba *hba)
{
}
static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
{
struct iblock_dev *ib_dev = NULL;
ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
if (!ib_dev) {
pr_err("Unable to allocate struct iblock_dev\n");
return NULL;
}
pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
return &ib_dev->dev;
}
static int iblock_configure_device(struct se_device *dev)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct request_queue *q;
struct block_device *bd = NULL;
struct blk_integrity *bi;
fmode_t mode;
unsigned int max_write_zeroes_sectors;
int ret = -ENOMEM;
if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
pr_err("Missing udev_path= parameters for IBLOCK\n");
return -EINVAL;
}
ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
if (ret) {
pr_err("IBLOCK: Unable to create bioset\n");
goto out;
}
pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
ib_dev->ibd_udev_path);
mode = FMODE_READ|FMODE_EXCL;
if (!ib_dev->ibd_readonly)
mode |= FMODE_WRITE;
else
dev->dev_flags |= DF_READ_ONLY;
bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
if (IS_ERR(bd)) {
ret = PTR_ERR(bd);
goto out_free_bioset;
}
ib_dev->ibd_bd = bd;
q = bdev_get_queue(bd);
dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
dev->dev_attrib.hw_queue_depth = q->nr_requests;
if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
pr_debug("IBLOCK: BLOCK Discard support available,"
" disabled by default\n");
/*
* Enable write same emulation for IBLOCK and use 0xFFFF as
* the smaller WRITE_SAME(10) only has a two-byte block count.
*/
max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
if (max_write_zeroes_sectors)
dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
else
dev->dev_attrib.max_write_same_len = 0xFFFF;
if (blk_queue_nonrot(q))
dev->dev_attrib.is_nonrot = 1;
bi = bdev_get_integrity(bd);
if (bi) {
struct bio_set *bs = &ib_dev->ibd_bio_set;
if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
!strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
pr_err("IBLOCK export of blk_integrity: %s not"
" supported\n", bi->profile->name);
ret = -ENOSYS;
goto out_blkdev_put;
}
if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
} else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
}
if (dev->dev_attrib.pi_prot_type) {
if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
pr_err("Unable to allocate bioset for PI\n");
ret = -ENOMEM;
goto out_blkdev_put;
}
pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
&bs->bio_integrity_pool);
}
dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
}
return 0;
out_blkdev_put:
blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
out_free_bioset:
bioset_exit(&ib_dev->ibd_bio_set);
out:
return ret;
}
static void iblock_dev_call_rcu(struct rcu_head *p)
{
struct se_device *dev = container_of(p, struct se_device, rcu_head);
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
kfree(ib_dev);
}
static void iblock_free_device(struct se_device *dev)
{
call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
}
static void iblock_destroy_device(struct se_device *dev)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
if (ib_dev->ibd_bd != NULL)
blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
bioset_exit(&ib_dev->ibd_bio_set);
}
static unsigned long long iblock_emulate_read_cap_with_block_size(
struct se_device *dev,
struct block_device *bd,
struct request_queue *q)
{
unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
bdev_logical_block_size(bd)) - 1);
u32 block_size = bdev_logical_block_size(bd);
if (block_size == dev->dev_attrib.block_size)
return blocks_long;
switch (block_size) {
case 4096:
switch (dev->dev_attrib.block_size) {
case 2048:
blocks_long <<= 1;
break;
case 1024:
blocks_long <<= 2;
break;
case 512:
blocks_long <<= 3;
default:
break;
}
break;
case 2048:
switch (dev->dev_attrib.block_size) {
case 4096:
blocks_long >>= 1;
break;
case 1024:
blocks_long <<= 1;
break;
case 512:
blocks_long <<= 2;
break;
default:
break;
}
break;
case 1024:
switch (dev->dev_attrib.block_size) {
case 4096:
blocks_long >>= 2;
break;
case 2048:
blocks_long >>= 1;
break;
case 512:
blocks_long <<= 1;
break;
default:
break;
}
break;
case 512:
switch (dev->dev_attrib.block_size) {
case 4096:
blocks_long >>= 3;
break;
case 2048:
blocks_long >>= 2;
break;
case 1024:
blocks_long >>= 1;
break;
default:
break;
}
break;
default:
break;
}
return blocks_long;
}
static void iblock_complete_cmd(struct se_cmd *cmd)
{
struct iblock_req *ibr = cmd->priv;
u8 status;
if (!refcount_dec_and_test(&ibr->pending))
return;
if (atomic_read(&ibr->ib_bio_err_cnt))
status = SAM_STAT_CHECK_CONDITION;
else
status = SAM_STAT_GOOD;
target_complete_cmd(cmd, status);
kfree(ibr);
}
static void iblock_bio_done(struct bio *bio)
{
struct se_cmd *cmd = bio->bi_private;
struct iblock_req *ibr = cmd->priv;
if (bio->bi_status) {
pr_err("bio error: %p, err: %d\n", bio, bio->bi_status);
/*
* Bump the ib_bio_err_cnt and release bio.
*/
atomic_inc(&ibr->ib_bio_err_cnt);
smp_mb__after_atomic();
}
bio_put(bio);
iblock_complete_cmd(cmd);
}
static struct bio *
iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
int op_flags)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
struct bio *bio;
/*
* Only allocate as many vector entries as the bio code allows us to,
* we'll loop later on until we have handled the whole request.
*/
if (sg_num > BIO_MAX_PAGES)
sg_num = BIO_MAX_PAGES;
bio = bio_alloc_bioset(GFP_NOIO, sg_num, &ib_dev->ibd_bio_set);
if (!bio) {
pr_err("Unable to allocate memory for bio\n");
return NULL;
}
bio_set_dev(bio, ib_dev->ibd_bd);
bio->bi_private = cmd;
bio->bi_end_io = &iblock_bio_done;
bio->bi_iter.bi_sector = lba;
bio_set_op_attrs(bio, op, op_flags);
return bio;
}
static void iblock_submit_bios(struct bio_list *list)
{
struct blk_plug plug;
struct bio *bio;
blk_start_plug(&plug);
while ((bio = bio_list_pop(list)))
submit_bio(bio);
blk_finish_plug(&plug);
}
static void iblock_end_io_flush(struct bio *bio)
{
struct se_cmd *cmd = bio->bi_private;
if (bio->bi_status)
pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
if (cmd) {
if (bio->bi_status)
target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
else
target_complete_cmd(cmd, SAM_STAT_GOOD);
}
bio_put(bio);
}
/*
* Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
* always flush the whole cache.
*/
static sense_reason_t
iblock_execute_sync_cache(struct se_cmd *cmd)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
int immed = (cmd->t_task_cdb[1] & 0x2);
struct bio *bio;
/*
* If the Immediate bit is set, queue up the GOOD response
* for this SYNCHRONIZE_CACHE op.
*/
if (immed)
target_complete_cmd(cmd, SAM_STAT_GOOD);
bio = bio_alloc(GFP_KERNEL, 0);
bio->bi_end_io = iblock_end_io_flush;
bio_set_dev(bio, ib_dev->ibd_bd);
bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
if (!immed)
bio->bi_private = cmd;
submit_bio(bio);
return 0;
}
static sense_reason_t
iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
{
struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
struct se_device *dev = cmd->se_dev;
int ret;
ret = blkdev_issue_discard(bdev,
target_to_linux_sector(dev, lba),
target_to_linux_sector(dev, nolb),
GFP_KERNEL, 0);
if (ret < 0) {
pr_err("blkdev_issue_discard() failed: %d\n", ret);
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
return 0;
}
static sense_reason_t
iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct scatterlist *sg = &cmd->t_data_sg[0];
unsigned char *buf, *not_zero;
int ret;
buf = kmap(sg_page(sg)) + sg->offset;
if (!buf)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
/*
* Fall back to block_execute_write_same() slow-path if
* incoming WRITE_SAME payload does not contain zeros.
*/
not_zero = memchr_inv(buf, 0x00, cmd->data_length);
kunmap(sg_page(sg));
if (not_zero)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
ret = blkdev_issue_zeroout(bdev,
target_to_linux_sector(dev, cmd->t_task_lba),
target_to_linux_sector(dev,
sbc_get_write_same_sectors(cmd)),
GFP_KERNEL, false);
if (ret)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
target_complete_cmd(cmd, GOOD);
return 0;
}
static sense_reason_t
iblock_execute_write_same(struct se_cmd *cmd)
{
struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
struct iblock_req *ibr;
struct scatterlist *sg;
struct bio *bio;
struct bio_list list;
struct se_device *dev = cmd->se_dev;
sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
sector_t sectors = target_to_linux_sector(dev,
sbc_get_write_same_sectors(cmd));
if (cmd->prot_op) {
pr_err("WRITE_SAME: Protection information with IBLOCK"
" backends not supported\n");
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
sg = &cmd->t_data_sg[0];
if (cmd->t_data_nents > 1 ||
sg->length != cmd->se_dev->dev_attrib.block_size) {
pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
" block_size: %u\n", cmd->t_data_nents, sg->length,
cmd->se_dev->dev_attrib.block_size);
return TCM_INVALID_CDB_FIELD;
}
if (bdev_write_zeroes_sectors(bdev)) {
if (!iblock_execute_zero_out(bdev, cmd))
return 0;
}
ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
if (!ibr)
goto fail;
cmd->priv = ibr;
bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0);
if (!bio)
goto fail_free_ibr;
bio_list_init(&list);
bio_list_add(&list, bio);
refcount_set(&ibr->pending, 1);
while (sectors) {
while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
!= sg->length) {
bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE,
0);
if (!bio)
goto fail_put_bios;
refcount_inc(&ibr->pending);
bio_list_add(&list, bio);
}
/* Always in 512 byte units for Linux/Block */
block_lba += sg->length >> SECTOR_SHIFT;
sectors -= sg->length >> SECTOR_SHIFT;
}
iblock_submit_bios(&list);
return 0;
fail_put_bios:
while ((bio = bio_list_pop(&list)))
bio_put(bio);
fail_free_ibr:
kfree(ibr);
fail:
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
enum {
Opt_udev_path, Opt_readonly, Opt_force, Opt_err
};
static match_table_t tokens = {
{Opt_udev_path, "udev_path=%s"},
{Opt_readonly, "readonly=%d"},
{Opt_force, "force=%d"},
{Opt_err, NULL}
};
static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
const char *page, ssize_t count)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
char *orig, *ptr, *arg_p, *opts;
substring_t args[MAX_OPT_ARGS];
int ret = 0, token;
unsigned long tmp_readonly;
opts = kstrdup(page, GFP_KERNEL);
if (!opts)
return -ENOMEM;
orig = opts;
while ((ptr = strsep(&opts, ",\n")) != NULL) {
if (!*ptr)
continue;
token = match_token(ptr, tokens, args);
switch (token) {
case Opt_udev_path:
if (ib_dev->ibd_bd) {
pr_err("Unable to set udev_path= while"
" ib_dev->ibd_bd exists\n");
ret = -EEXIST;
goto out;
}
if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
SE_UDEV_PATH_LEN) == 0) {
ret = -EINVAL;
break;
}
pr_debug("IBLOCK: Referencing UDEV path: %s\n",
ib_dev->ibd_udev_path);
ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
break;
case Opt_readonly:
arg_p = match_strdup(&args[0]);
if (!arg_p) {
ret = -ENOMEM;
break;
}
ret = kstrtoul(arg_p, 0, &tmp_readonly);
kfree(arg_p);
if (ret < 0) {
pr_err("kstrtoul() failed for"
" readonly=\n");
goto out;
}
ib_dev->ibd_readonly = tmp_readonly;
pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
break;
case Opt_force:
break;
default:
break;
}
}
out:
kfree(orig);
return (!ret) ? count : ret;
}
static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct block_device *bd = ib_dev->ibd_bd;
char buf[BDEVNAME_SIZE];
ssize_t bl = 0;
if (bd)
bl += sprintf(b + bl, "iBlock device: %s",
bdevname(bd, buf));
if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
bl += sprintf(b + bl, " UDEV PATH: %s",
ib_dev->ibd_udev_path);
bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
bl += sprintf(b + bl, " ");
if (bd) {
bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
"" : (bd->bd_holder == ib_dev) ?
"CLAIMED: IBLOCK" : "CLAIMED: OS");
} else {
bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
}
return bl;
}
static int
iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio,
struct sg_mapping_iter *miter)
{
struct se_device *dev = cmd->se_dev;
struct blk_integrity *bi;
struct bio_integrity_payload *bip;
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
int rc;
size_t resid, len;
bi = bdev_get_integrity(ib_dev->ibd_bd);
if (!bi) {
pr_err("Unable to locate bio_integrity\n");
return -ENODEV;
}
bip = bio_integrity_alloc(bio, GFP_NOIO,
min_t(unsigned int, cmd->t_prot_nents, BIO_MAX_PAGES));
if (IS_ERR(bip)) {
pr_err("Unable to allocate bio_integrity_payload\n");
return PTR_ERR(bip);
}
bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
bip_set_seed(bip, bio->bi_iter.bi_sector);
pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
(unsigned long long)bip->bip_iter.bi_sector);
resid = bip->bip_iter.bi_size;
while (resid > 0 && sg_miter_next(miter)) {
len = min_t(size_t, miter->length, resid);
rc = bio_integrity_add_page(bio, miter->page, len,
offset_in_page(miter->addr));
if (rc != len) {
pr_err("bio_integrity_add_page() failed; %d\n", rc);
sg_miter_stop(miter);
return -ENOMEM;
}
pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n",
miter->page, len, offset_in_page(miter->addr));
resid -= len;
if (len < miter->length)
miter->consumed -= miter->length - len;
}
sg_miter_stop(miter);
return 0;
}
static sense_reason_t
iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
enum dma_data_direction data_direction)
{
struct se_device *dev = cmd->se_dev;
sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
struct iblock_req *ibr;
struct bio *bio;
struct bio_list list;
struct scatterlist *sg;
u32 sg_num = sgl_nents;
unsigned bio_cnt;
int i, rc, op, op_flags = 0;
struct sg_mapping_iter prot_miter;
if (data_direction == DMA_TO_DEVICE) {
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
/*
* Force writethrough using REQ_FUA if a volatile write cache
* is not enabled, or if initiator set the Force Unit Access bit.
*/
op = REQ_OP_WRITE;
if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
if (cmd->se_cmd_flags & SCF_FUA)
op_flags = REQ_FUA;
else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
op_flags = REQ_FUA;
}
} else {
op = REQ_OP_READ;
}
ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
if (!ibr)
goto fail;
cmd->priv = ibr;
if (!sgl_nents) {
refcount_set(&ibr->pending, 1);
iblock_complete_cmd(cmd);
return 0;
}
bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
if (!bio)
goto fail_free_ibr;
bio_list_init(&list);
bio_list_add(&list, bio);
refcount_set(&ibr->pending, 2);
bio_cnt = 1;
if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
op == REQ_OP_READ ? SG_MITER_FROM_SG :
SG_MITER_TO_SG);
for_each_sg(sgl, sg, sgl_nents, i) {
/*
* XXX: if the length the device accepts is shorter than the
* length of the S/G list entry this will cause and
* endless loop. Better hope no driver uses huge pages.
*/
while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
!= sg->length) {
if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
rc = iblock_alloc_bip(cmd, bio, &prot_miter);
if (rc)
goto fail_put_bios;
}
if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
iblock_submit_bios(&list);
bio_cnt = 0;
}
bio = iblock_get_bio(cmd, block_lba, sg_num, op,
op_flags);
if (!bio)
goto fail_put_bios;
refcount_inc(&ibr->pending);
bio_list_add(&list, bio);
bio_cnt++;
}
/* Always in 512 byte units for Linux/Block */
block_lba += sg->length >> SECTOR_SHIFT;
sg_num--;
}
if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
rc = iblock_alloc_bip(cmd, bio, &prot_miter);
if (rc)
goto fail_put_bios;
}
iblock_submit_bios(&list);
iblock_complete_cmd(cmd);
return 0;
fail_put_bios:
while ((bio = bio_list_pop(&list)))
bio_put(bio);
fail_free_ibr:
kfree(ibr);
fail:
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
static sector_t iblock_get_blocks(struct se_device *dev)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct block_device *bd = ib_dev->ibd_bd;
struct request_queue *q = bdev_get_queue(bd);
return iblock_emulate_read_cap_with_block_size(dev, bd, q);
}
static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct block_device *bd = ib_dev->ibd_bd;
int ret;
ret = bdev_alignment_offset(bd);
if (ret == -1)
return 0;
/* convert offset-bytes to offset-lbas */
return ret / bdev_logical_block_size(bd);
}
static unsigned int iblock_get_lbppbe(struct se_device *dev)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct block_device *bd = ib_dev->ibd_bd;
int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
return ilog2(logs_per_phys);
}
static unsigned int iblock_get_io_min(struct se_device *dev)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct block_device *bd = ib_dev->ibd_bd;
return bdev_io_min(bd);
}
static unsigned int iblock_get_io_opt(struct se_device *dev)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct block_device *bd = ib_dev->ibd_bd;
return bdev_io_opt(bd);
}
static struct sbc_ops iblock_sbc_ops = {
.execute_rw = iblock_execute_rw,
.execute_sync_cache = iblock_execute_sync_cache,
.execute_write_same = iblock_execute_write_same,
.execute_unmap = iblock_execute_unmap,
};
static sense_reason_t
iblock_parse_cdb(struct se_cmd *cmd)
{
return sbc_parse_cdb(cmd, &iblock_sbc_ops);
}
static bool iblock_get_write_cache(struct se_device *dev)
{
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct block_device *bd = ib_dev->ibd_bd;
struct request_queue *q = bdev_get_queue(bd);
return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
}
static const struct target_backend_ops iblock_ops = {
.name = "iblock",
.inquiry_prod = "IBLOCK",
.inquiry_rev = IBLOCK_VERSION,
.owner = THIS_MODULE,
.attach_hba = iblock_attach_hba,
.detach_hba = iblock_detach_hba,
.alloc_device = iblock_alloc_device,
.configure_device = iblock_configure_device,
.destroy_device = iblock_destroy_device,
.free_device = iblock_free_device,
.parse_cdb = iblock_parse_cdb,
.set_configfs_dev_params = iblock_set_configfs_dev_params,
.show_configfs_dev_params = iblock_show_configfs_dev_params,
.get_device_type = sbc_get_device_type,
.get_blocks = iblock_get_blocks,
.get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
.get_lbppbe = iblock_get_lbppbe,
.get_io_min = iblock_get_io_min,
.get_io_opt = iblock_get_io_opt,
.get_write_cache = iblock_get_write_cache,
.tb_dev_attrib_attrs = sbc_attrib_attrs,
};
static int __init iblock_module_init(void)
{
return transport_backend_register(&iblock_ops);
}
static void __exit iblock_module_exit(void)
{
target_backend_unregister(&iblock_ops);
}
MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
MODULE_AUTHOR("nab@Linux-iSCSI.org");
MODULE_LICENSE("GPL");
module_init(iblock_module_init);
module_exit(iblock_module_exit);