linux/drivers/target/target_core_iblock.c
Linus Torvalds 5c755fe142 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "It's been a busy development cycle for target-core in a number of
  different areas.

  The fabric API usage for se_node_acl allocation is now within
  target-core code, dropping the external API callers for all fabric
  drivers tree-wide.

  There is a new conversion to RCU hlists for se_node_acl and
  se_portal_group LUN mappings, that turns fast-past LUN lookup into a
  completely lockless code-path.  It also removes the original
  hard-coded limitation of 256 LUNs per fabric endpoint.

  The configfs attributes for backends can now be shared between core
  and driver code, allowing existing drivers to use common code while
  still allowing flexibility for new backend provided attributes.

  The highlights include:

   - Merge sbc_verify_dif_* into common code (sagi)
   - Remove iscsi-target support for obsolete IFMarker/OFMarker
     (Christophe Vu-Brugier)
   - Add bidi support in target/user backend (ilias + vangelis + agover)
   - Move se_node_acl allocation into target-core code (hch)
   - Add crc_t10dif_update common helper (akinobu + mkp)
   - Handle target-core odd SGL mapping for data transfer memory
     (akinobu)
   - Move transport ID handling into target-core (hch)
   - Move task tag into struct se_cmd + support 64-bit tags (bart)
   - Convert se_node_acl->device_list[] to RCU hlist (nab + hch +
     paulmck)
   - Convert se_portal_group->tpg_lun_list[] to RCU hlist (nab + hch +
     paulmck)
   - Simplify target backend driver registration (hch)
   - Consolidate + simplify target backend attribute implementations
     (hch + nab)
   - Subsume se_port + t10_alua_tg_pt_gp_member into se_lun (hch)
   - Drop lun_sep_lock for se_lun->lun_se_dev RCU usage (hch + nab)
   - Drop unnecessary core_tpg_register TFO parameter (nab)
   - Use 64-bit LUNs tree-wide (hannes)
   - Drop left-over TARGET_MAX_LUNS_PER_TRANSPORT limit (hannes)"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (76 commits)
  target: Bump core version to v5.0
  target: remove target_core_configfs.h
  target: remove unused TARGET_CORE_CONFIG_ROOT define
  target: consolidate version defines
  target: implement WRITE_SAME with UNMAP bit using ->execute_unmap
  target: simplify UNMAP handling
  target: replace se_cmd->execute_rw with a protocol_data field
  target/user: Fix inconsistent kmap_atomic/kunmap_atomic
  target: Send UA when changing LUN inventory
  target: Send UA upon LUN RESET tmr completion
  target: Send UA on ALUA target port group change
  target: Convert se_lun->lun_deve_lock to normal spinlock
  target: use 'se_dev_entry' when allocating UAs
  target: Remove 'ua_nacl' pointer from se_ua structure
  target_core_alua: Correct UA handling when switching states
  xen-scsiback: Fix compile warning for 64-bit LUN
  target: Remove TARGET_MAX_LUNS_PER_TRANSPORT
  target: use 64-bit LUNs
  target: Drop duplicate + unused se_dev_check_wce
  target: Drop unnecessary core_tpg_register TFO parameter
  ...
2015-07-04 14:13:43 -07:00

880 lines
21 KiB
C

/*******************************************************************************
* 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>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
******************************************************************************/
#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;
int ret = -ENOMEM;
if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
pr_err("Missing udev_path= parameters for IBLOCK\n");
return -EINVAL;
}
ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
if (!ib_dev->ibd_bio_set) {
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;
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;
/*
* Check if the underlying struct block_device request_queue supports
* the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
* in ATA and we need to set TPE=1
*/
if (blk_queue_discard(q)) {
dev->dev_attrib.max_unmap_lba_count =
q->limits.max_discard_sectors;
/*
* Currently hardcoded to 1 in Linux/SCSI code..
*/
dev->dev_attrib.max_unmap_block_desc_count = 1;
dev->dev_attrib.unmap_granularity =
q->limits.discard_granularity >> 9;
dev->dev_attrib.unmap_granularity_alignment =
q->limits.discard_alignment;
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.
*/
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->name, "T10-DIF-TYPE3-IP") ||
!strcmp(bi->name, "T10-DIF-TYPE1-IP")) {
pr_err("IBLOCK export of blk_integrity: %s not"
" supported\n", bi->name);
ret = -ENOSYS;
goto out_blkdev_put;
}
if (!strcmp(bi->name, "T10-DIF-TYPE3-CRC")) {
dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
} else if (!strcmp(bi->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_free(ib_dev->ibd_bio_set);
ib_dev->ibd_bio_set = NULL;
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)
{
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);
if (ib_dev->ibd_bio_set != NULL)
bioset_free(ib_dev->ibd_bio_set);
call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
}
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 (!atomic_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, int err)
{
struct se_cmd *cmd = bio->bi_private;
struct iblock_req *ibr = cmd->priv;
/*
* Set -EIO if !BIO_UPTODATE and the passed is still err=0
*/
if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
err = -EIO;
if (err != 0) {
pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
" err: %d\n", bio, err);
/*
* 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)
{
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->bi_bdev = ib_dev->ibd_bd;
bio->bi_private = cmd;
bio->bi_end_io = &iblock_bio_done;
bio->bi_iter.bi_sector = lba;
return bio;
}
static void iblock_submit_bios(struct bio_list *list, int rw)
{
struct blk_plug plug;
struct bio *bio;
blk_start_plug(&plug);
while ((bio = bio_list_pop(list)))
submit_bio(rw, bio);
blk_finish_plug(&plug);
}
static void iblock_end_io_flush(struct bio *bio, int err)
{
struct se_cmd *cmd = bio->bi_private;
if (err)
pr_err("IBLOCK: cache flush failed: %d\n", err);
if (cmd) {
if (err)
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->bi_bdev = ib_dev->ibd_bd;
if (!immed)
bio->bi_private = cmd;
submit_bio(WRITE_FLUSH, 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;
int ret;
ret = blkdev_issue_discard(bdev, lba, 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_write_same(struct se_cmd *cmd)
{
struct iblock_req *ibr;
struct scatterlist *sg;
struct bio *bio;
struct bio_list list;
sector_t block_lba = cmd->t_task_lba;
sector_t sectors = 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;
}
ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
if (!ibr)
goto fail;
cmd->priv = ibr;
bio = iblock_get_bio(cmd, block_lba, 1);
if (!bio)
goto fail_free_ibr;
bio_list_init(&list);
bio_list_add(&list, bio);
atomic_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);
if (!bio)
goto fail_put_bios;
atomic_inc(&ibr->pending);
bio_list_add(&list, bio);
}
/* Always in 512 byte units for Linux/Block */
block_lba += sg->length >> IBLOCK_LBA_SHIFT;
sectors -= 1;
}
iblock_submit_bios(&list, WRITE);
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 se_device *dev = cmd->se_dev;
struct blk_integrity *bi;
struct bio_integrity_payload *bip;
struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
struct scatterlist *sg;
int i, rc;
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, cmd->t_prot_nents);
if (!bip) {
pr_err("Unable to allocate bio_integrity_payload\n");
return -ENOMEM;
}
bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
dev->prot_length;
bip->bip_iter.bi_sector = 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);
for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
sg->offset);
if (rc != sg->length) {
pr_err("bio_integrity_add_page() failed; %d\n", rc);
return -ENOMEM;
}
pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
sg_page(sg), sg->length, sg->offset);
}
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;
struct iblock_req *ibr;
struct bio *bio, *bio_start;
struct bio_list list;
struct scatterlist *sg;
u32 sg_num = sgl_nents;
sector_t block_lba;
unsigned bio_cnt;
int rw = 0;
int i;
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 WRITE_FUA if a volatile write cache
* is not enabled, or if initiator set the Force Unit Access bit.
*/
if (q->flush_flags & REQ_FUA) {
if (cmd->se_cmd_flags & SCF_FUA)
rw = WRITE_FUA;
else if (!(q->flush_flags & REQ_FLUSH))
rw = WRITE_FUA;
else
rw = WRITE;
} else {
rw = WRITE;
}
} else {
rw = READ;
}
/*
* Convert the blocksize advertised to the initiator to the 512 byte
* units unconditionally used by the Linux block layer.
*/
if (dev->dev_attrib.block_size == 4096)
block_lba = (cmd->t_task_lba << 3);
else if (dev->dev_attrib.block_size == 2048)
block_lba = (cmd->t_task_lba << 2);
else if (dev->dev_attrib.block_size == 1024)
block_lba = (cmd->t_task_lba << 1);
else if (dev->dev_attrib.block_size == 512)
block_lba = cmd->t_task_lba;
else {
pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
" %u\n", dev->dev_attrib.block_size);
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
if (!ibr)
goto fail;
cmd->priv = ibr;
if (!sgl_nents) {
atomic_set(&ibr->pending, 1);
iblock_complete_cmd(cmd);
return 0;
}
bio = iblock_get_bio(cmd, block_lba, sgl_nents);
if (!bio)
goto fail_free_ibr;
bio_start = bio;
bio_list_init(&list);
bio_list_add(&list, bio);
atomic_set(&ibr->pending, 2);
bio_cnt = 1;
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 (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
iblock_submit_bios(&list, rw);
bio_cnt = 0;
}
bio = iblock_get_bio(cmd, block_lba, sg_num);
if (!bio)
goto fail_put_bios;
atomic_inc(&ibr->pending);
bio_list_add(&list, bio);
bio_cnt++;
}
/* Always in 512 byte units for Linux/Block */
block_lba += sg->length >> IBLOCK_LBA_SHIFT;
sg_num--;
}
if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
int rc = iblock_alloc_bip(cmd, bio_start);
if (rc)
goto fail_put_bios;
}
iblock_submit_bios(&list, rw);
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 q->flush_flags & REQ_FLUSH;
}
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,
.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);