diff options
Diffstat (limited to 'drivers/target/target_core_iblock.c')
-rw-r--r-- | drivers/target/target_core_iblock.c | 808 |
1 files changed, 808 insertions, 0 deletions
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c new file mode 100644 index 00000000000..c6e0d757e76 --- /dev/null +++ b/drivers/target/target_core_iblock.c @@ -0,0 +1,808 @@ +/******************************************************************************* + * Filename: target_core_iblock.c + * + * This file contains the Storage Engine <-> Linux BlockIO transport + * specific functions. + * + * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc. + * Copyright (c) 2005, 2006, 2007 SBE, Inc. + * Copyright (c) 2007-2010 Rising Tide Systems + * Copyright (c) 2008-2010 Linux-iSCSI.org + * + * 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/version.h> +#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/smp_lock.h> +#include <linux/bio.h> +#include <linux/genhd.h> +#include <linux/file.h> +#include <scsi/scsi.h> +#include <scsi/scsi_host.h> + +#include <target/target_core_base.h> +#include <target/target_core_device.h> +#include <target/target_core_transport.h> + +#include "target_core_iblock.h" + +#if 0 +#define DEBUG_IBLOCK(x...) printk(x) +#else +#define DEBUG_IBLOCK(x...) +#endif + +static struct se_subsystem_api iblock_template; + +static void iblock_bio_done(struct bio *, int); + +/* iblock_attach_hba(): (Part of se_subsystem_api_t template) + * + * + */ +static int iblock_attach_hba(struct se_hba *hba, u32 host_id) +{ + struct iblock_hba *ib_host; + + ib_host = kzalloc(sizeof(struct iblock_hba), GFP_KERNEL); + if (!(ib_host)) { + printk(KERN_ERR "Unable to allocate memory for" + " struct iblock_hba\n"); + return -ENOMEM; + } + + ib_host->iblock_host_id = host_id; + + atomic_set(&hba->left_queue_depth, IBLOCK_HBA_QUEUE_DEPTH); + atomic_set(&hba->max_queue_depth, IBLOCK_HBA_QUEUE_DEPTH); + hba->hba_ptr = (void *) ib_host; + + printk(KERN_INFO "CORE_HBA[%d] - TCM iBlock HBA Driver %s on" + " Generic Target Core Stack %s\n", hba->hba_id, + IBLOCK_VERSION, TARGET_CORE_MOD_VERSION); + + printk(KERN_INFO "CORE_HBA[%d] - Attached iBlock HBA: %u to Generic" + " Target Core TCQ Depth: %d\n", hba->hba_id, + ib_host->iblock_host_id, atomic_read(&hba->max_queue_depth)); + + return 0; +} + +static void iblock_detach_hba(struct se_hba *hba) +{ + struct iblock_hba *ib_host = hba->hba_ptr; + + printk(KERN_INFO "CORE_HBA[%d] - Detached iBlock HBA: %u from Generic" + " Target Core\n", hba->hba_id, ib_host->iblock_host_id); + + kfree(ib_host); + hba->hba_ptr = NULL; +} + +static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name) +{ + struct iblock_dev *ib_dev = NULL; + struct iblock_hba *ib_host = hba->hba_ptr; + + ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL); + if (!(ib_dev)) { + printk(KERN_ERR "Unable to allocate struct iblock_dev\n"); + return NULL; + } + ib_dev->ibd_host = ib_host; + + printk(KERN_INFO "IBLOCK: Allocated ib_dev for %s\n", name); + + return ib_dev; +} + +static struct se_device *iblock_create_virtdevice( + struct se_hba *hba, + struct se_subsystem_dev *se_dev, + void *p) +{ + struct iblock_dev *ib_dev = p; + struct se_device *dev; + struct se_dev_limits dev_limits; + struct block_device *bd = NULL; + struct request_queue *q; + struct queue_limits *limits; + u32 dev_flags = 0; + + if (!(ib_dev)) { + printk(KERN_ERR "Unable to locate struct iblock_dev parameter\n"); + return 0; + } + memset(&dev_limits, 0, sizeof(struct se_dev_limits)); + /* + * These settings need to be made tunable.. + */ + ib_dev->ibd_bio_set = bioset_create(32, 64); + if (!(ib_dev->ibd_bio_set)) { + printk(KERN_ERR "IBLOCK: Unable to create bioset()\n"); + return 0; + } + printk(KERN_INFO "IBLOCK: Created bio_set()\n"); + /* + * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path + * must already have been set in order for echo 1 > $HBA/$DEV/enable to run. + */ + printk(KERN_INFO "IBLOCK: Claiming struct block_device: %s\n", + ib_dev->ibd_udev_path); + + bd = blkdev_get_by_path(ib_dev->ibd_udev_path, + FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev); + if (!(bd)) + goto failed; + /* + * Setup the local scope queue_limits from struct request_queue->limits + * to pass into transport_add_device_to_core_hba() as struct se_dev_limits. + */ + q = bdev_get_queue(bd); + limits = &dev_limits.limits; + limits->logical_block_size = bdev_logical_block_size(bd); + limits->max_hw_sectors = queue_max_hw_sectors(q); + limits->max_sectors = queue_max_sectors(q); + dev_limits.hw_queue_depth = IBLOCK_MAX_DEVICE_QUEUE_DEPTH; + dev_limits.queue_depth = IBLOCK_DEVICE_QUEUE_DEPTH; + + ib_dev->ibd_major = MAJOR(bd->bd_dev); + ib_dev->ibd_minor = MINOR(bd->bd_dev); + ib_dev->ibd_bd = bd; + + dev = transport_add_device_to_core_hba(hba, + &iblock_template, se_dev, dev_flags, (void *)ib_dev, + &dev_limits, "IBLOCK", IBLOCK_VERSION); + if (!(dev)) + goto failed; + + ib_dev->ibd_depth = dev->queue_depth; + + /* + * 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(bdev_get_queue(bd))) { + struct request_queue *q = bdev_get_queue(bd); + + DEV_ATTRIB(dev)->max_unmap_lba_count = + q->limits.max_discard_sectors; + /* + * Currently hardcoded to 1 in Linux/SCSI code.. + */ + DEV_ATTRIB(dev)->max_unmap_block_desc_count = 1; + DEV_ATTRIB(dev)->unmap_granularity = + q->limits.discard_granularity; + DEV_ATTRIB(dev)->unmap_granularity_alignment = + q->limits.discard_alignment; + + printk(KERN_INFO "IBLOCK: BLOCK Discard support available," + " disabled by default\n"); + } + + return dev; + +failed: + if (ib_dev->ibd_bio_set) { + bioset_free(ib_dev->ibd_bio_set); + ib_dev->ibd_bio_set = NULL; + } + ib_dev->ibd_bd = NULL; + ib_dev->ibd_major = 0; + ib_dev->ibd_minor = 0; + return NULL; +} + +static void iblock_free_device(void *p) +{ + struct iblock_dev *ib_dev = p; + + blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); + bioset_free(ib_dev->ibd_bio_set); + kfree(ib_dev); +} + +static inline struct iblock_req *IBLOCK_REQ(struct se_task *task) +{ + return container_of(task, struct iblock_req, ib_task); +} + +static struct se_task * +iblock_alloc_task(struct se_cmd *cmd) +{ + struct iblock_req *ib_req; + + ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); + if (!(ib_req)) { + printk(KERN_ERR "Unable to allocate memory for struct iblock_req\n"); + return NULL; + } + + ib_req->ib_dev = SE_DEV(cmd)->dev_ptr; + atomic_set(&ib_req->ib_bio_cnt, 0); + return &ib_req->ib_task; +} + +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_ATTRIB(dev)->block_size) + return blocks_long; + + switch (block_size) { + case 4096: + switch (DEV_ATTRIB(dev)->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_ATTRIB(dev)->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_ATTRIB(dev)->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_ATTRIB(dev)->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; +} + +/* + * Emulate SYCHRONIZE_CACHE_* + */ +static void iblock_emulate_sync_cache(struct se_task *task) +{ + struct se_cmd *cmd = TASK_CMD(task); + struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr; + int immed = (T_TASK(cmd)->t_task_cdb[1] & 0x2); + sector_t error_sector; + int ret; + + /* + * If the Immediate bit is set, queue up the GOOD response + * for this SYNCHRONIZE_CACHE op + */ + if (immed) + transport_complete_sync_cache(cmd, 1); + + /* + * blkdev_issue_flush() does not support a specifying a range, so + * we have to flush the entire cache. + */ + ret = blkdev_issue_flush(ib_dev->ibd_bd, GFP_KERNEL, &error_sector); + if (ret != 0) { + printk(KERN_ERR "IBLOCK: block_issue_flush() failed: %d " + " error_sector: %llu\n", ret, + (unsigned long long)error_sector); + } + + if (!immed) + transport_complete_sync_cache(cmd, ret == 0); +} + +/* + * Tell TCM Core that we are capable of WriteCache emulation for + * an underlying struct se_device. + */ +static int iblock_emulated_write_cache(struct se_device *dev) +{ + return 1; +} + +static int iblock_emulated_dpo(struct se_device *dev) +{ + return 0; +} + +/* + * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs + * for TYPE_DISK. + */ +static int iblock_emulated_fua_write(struct se_device *dev) +{ + return 1; +} + +static int iblock_emulated_fua_read(struct se_device *dev) +{ + return 0; +} + +static int iblock_do_task(struct se_task *task) +{ + struct se_device *dev = task->task_se_cmd->se_dev; + struct iblock_req *req = IBLOCK_REQ(task); + struct iblock_dev *ibd = (struct iblock_dev *)req->ib_dev; + struct request_queue *q = bdev_get_queue(ibd->ibd_bd); + struct bio *bio = req->ib_bio, *nbio = NULL; + int rw; + + if (task->task_data_direction == DMA_TO_DEVICE) { + /* + * Force data to disk if we pretend to not have a volatile + * write cache, or the initiator set the Force Unit Access bit. + */ + if (DEV_ATTRIB(dev)->emulate_write_cache == 0 || + (DEV_ATTRIB(dev)->emulate_fua_write > 0 && + T_TASK(task->task_se_cmd)->t_tasks_fua)) + rw = WRITE_FUA; + else + rw = WRITE; + } else { + rw = READ; + } + + while (bio) { + nbio = bio->bi_next; + bio->bi_next = NULL; + DEBUG_IBLOCK("Calling submit_bio() task: %p bio: %p" + " bio->bi_sector: %llu\n", task, bio, bio->bi_sector); + + submit_bio(rw, bio); + bio = nbio; + } + + if (q->unplug_fn) + q->unplug_fn(q); + return PYX_TRANSPORT_SENT_TO_TRANSPORT; +} + +static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range) +{ + struct iblock_dev *ibd = dev->dev_ptr; + struct block_device *bd = ibd->ibd_bd; + int barrier = 0; + + return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier); +} + +static void iblock_free_task(struct se_task *task) +{ + struct iblock_req *req = IBLOCK_REQ(task); + struct bio *bio, *hbio = req->ib_bio; + /* + * We only release the bio(s) here if iblock_bio_done() has not called + * bio_put() -> iblock_bio_destructor(). + */ + while (hbio != NULL) { + bio = hbio; + hbio = hbio->bi_next; + bio->bi_next = NULL; + bio_put(bio); + } + + kfree(req); +} + +enum { + Opt_udev_path, Opt_force, Opt_err +}; + +static match_table_t tokens = { + {Opt_udev_path, "udev_path=%s"}, + {Opt_force, "force=%d"}, + {Opt_err, NULL} +}; + +static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba, + struct se_subsystem_dev *se_dev, + const char *page, ssize_t count) +{ + struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr; + char *orig, *ptr, *opts; + substring_t args[MAX_OPT_ARGS]; + int ret = 0, arg, token; + + opts = kstrdup(page, GFP_KERNEL); + if (!opts) + return -ENOMEM; + + orig = opts; + + while ((ptr = strsep(&opts, ",")) != NULL) { + if (!*ptr) + continue; + + token = match_token(ptr, tokens, args); + switch (token) { + case Opt_udev_path: + if (ib_dev->ibd_bd) { + printk(KERN_ERR "Unable to set udev_path= while" + " ib_dev->ibd_bd exists\n"); + ret = -EEXIST; + goto out; + } + + ret = snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN, + "%s", match_strdup(&args[0])); + printk(KERN_INFO "IBLOCK: Referencing UDEV path: %s\n", + ib_dev->ibd_udev_path); + ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH; + break; + case Opt_force: + match_int(args, &arg); + ib_dev->ibd_force = arg; + printk(KERN_INFO "IBLOCK: Set force=%d\n", + ib_dev->ibd_force); + break; + default: + break; + } + } + +out: + kfree(orig); + return (!ret) ? count : ret; +} + +static ssize_t iblock_check_configfs_dev_params( + struct se_hba *hba, + struct se_subsystem_dev *se_dev) +{ + struct iblock_dev *ibd = se_dev->se_dev_su_ptr; + + if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) { + printk(KERN_ERR "Missing udev_path= parameters for IBLOCK\n"); + return -1; + } + + return 0; +} + +static ssize_t iblock_show_configfs_dev_params( + struct se_hba *hba, + struct se_subsystem_dev *se_dev, + char *b) +{ + struct iblock_dev *ibd = se_dev->se_dev_su_ptr; + struct block_device *bd = ibd->ibd_bd; + char buf[BDEVNAME_SIZE]; + ssize_t bl = 0; + + if (bd) + bl += sprintf(b + bl, "iBlock device: %s", + bdevname(bd, buf)); + if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) { + bl += sprintf(b + bl, " UDEV PATH: %s\n", + ibd->ibd_udev_path); + } else + bl += sprintf(b + bl, "\n"); + + bl += sprintf(b + bl, " "); + if (bd) { + bl += sprintf(b + bl, "Major: %d Minor: %d %s\n", + ibd->ibd_major, ibd->ibd_minor, (!bd->bd_contains) ? + "" : (bd->bd_holder == (struct iblock_dev *)ibd) ? + "CLAIMED: IBLOCK" : "CLAIMED: OS"); + } else { + bl += sprintf(b + bl, "Major: %d Minor: %d\n", + ibd->ibd_major, ibd->ibd_minor); + } + + return bl; +} + +static void iblock_bio_destructor(struct bio *bio) +{ + struct se_task *task = bio->bi_private; + struct iblock_dev *ib_dev = task->se_dev->dev_ptr; + + bio_free(bio, ib_dev->ibd_bio_set); +} + +static struct bio *iblock_get_bio( + struct se_task *task, + struct iblock_req *ib_req, + struct iblock_dev *ib_dev, + int *ret, + sector_t lba, + u32 sg_num) +{ + struct bio *bio; + + bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set); + if (!(bio)) { + printk(KERN_ERR "Unable to allocate memory for bio\n"); + *ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES; + return NULL; + } + + DEBUG_IBLOCK("Allocated bio: %p task_sg_num: %u using ibd_bio_set:" + " %p\n", bio, task->task_sg_num, ib_dev->ibd_bio_set); + DEBUG_IBLOCK("Allocated bio: %p task_size: %u\n", bio, task->task_size); + + bio->bi_bdev = ib_dev->ibd_bd; + bio->bi_private = (void *) task; + bio->bi_destructor = iblock_bio_destructor; + bio->bi_end_io = &iblock_bio_done; + bio->bi_sector = lba; + atomic_inc(&ib_req->ib_bio_cnt); + + DEBUG_IBLOCK("Set bio->bi_sector: %llu\n", bio->bi_sector); + DEBUG_IBLOCK("Set ib_req->ib_bio_cnt: %d\n", + atomic_read(&ib_req->ib_bio_cnt)); + return bio; +} + +static int iblock_map_task_SG(struct se_task *task) +{ + struct se_cmd *cmd = task->task_se_cmd; + struct se_device *dev = SE_DEV(cmd); + struct iblock_dev *ib_dev = task->se_dev->dev_ptr; + struct iblock_req *ib_req = IBLOCK_REQ(task); + struct bio *bio = NULL, *hbio = NULL, *tbio = NULL; + struct scatterlist *sg; + int ret = 0; + u32 i, sg_num = task->task_sg_num; + sector_t block_lba; + /* + * Do starting conversion up from non 512-byte blocksize with + * struct se_task SCSI blocksize into Linux/Block 512 units for BIO. + */ + if (DEV_ATTRIB(dev)->block_size == 4096) + block_lba = (task->task_lba << 3); + else if (DEV_ATTRIB(dev)->block_size == 2048) + block_lba = (task->task_lba << 2); + else if (DEV_ATTRIB(dev)->block_size == 1024) + block_lba = (task->task_lba << 1); + else if (DEV_ATTRIB(dev)->block_size == 512) + block_lba = task->task_lba; + else { + printk(KERN_ERR "Unsupported SCSI -> BLOCK LBA conversion:" + " %u\n", DEV_ATTRIB(dev)->block_size); + return PYX_TRANSPORT_LU_COMM_FAILURE; + } + + bio = iblock_get_bio(task, ib_req, ib_dev, &ret, block_lba, sg_num); + if (!(bio)) + return ret; + + ib_req->ib_bio = bio; + hbio = tbio = bio; + /* + * Use fs/bio.c:bio_add_pages() to setup the bio_vec maplist + * from TCM struct se_mem -> task->task_sg -> struct scatterlist memory. + */ + for_each_sg(task->task_sg, sg, task->task_sg_num, i) { + DEBUG_IBLOCK("task: %p bio: %p Calling bio_add_page(): page:" + " %p len: %u offset: %u\n", task, bio, sg_page(sg), + sg->length, sg->offset); +again: + ret = bio_add_page(bio, sg_page(sg), sg->length, sg->offset); + if (ret != sg->length) { + + DEBUG_IBLOCK("*** Set bio->bi_sector: %llu\n", + bio->bi_sector); + DEBUG_IBLOCK("** task->task_size: %u\n", + task->task_size); + DEBUG_IBLOCK("*** bio->bi_max_vecs: %u\n", + bio->bi_max_vecs); + DEBUG_IBLOCK("*** bio->bi_vcnt: %u\n", + bio->bi_vcnt); + + bio = iblock_get_bio(task, ib_req, ib_dev, &ret, + block_lba, sg_num); + if (!(bio)) + goto fail; + + tbio = tbio->bi_next = bio; + DEBUG_IBLOCK("-----------------> Added +1 bio: %p to" + " list, Going to again\n", bio); + goto again; + } + /* Always in 512 byte units for Linux/Block */ + block_lba += sg->length >> IBLOCK_LBA_SHIFT; + sg_num--; + DEBUG_IBLOCK("task: %p bio-add_page() passed!, decremented" + " sg_num to %u\n", task, sg_num); + DEBUG_IBLOCK("task: %p bio_add_page() passed!, increased lba" + " to %llu\n", task, block_lba); + DEBUG_IBLOCK("task: %p bio_add_page() passed!, bio->bi_vcnt:" + " %u\n", task, bio->bi_vcnt); + } + + return 0; +fail: + while (hbio) { + bio = hbio; + hbio = hbio->bi_next; + bio->bi_next = NULL; + bio_put(bio); + } + return ret; +} + +static unsigned char *iblock_get_cdb(struct se_task *task) +{ + return IBLOCK_REQ(task)->ib_scsi_cdb; +} + +static u32 iblock_get_device_rev(struct se_device *dev) +{ + return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */ +} + +static u32 iblock_get_device_type(struct se_device *dev) +{ + return TYPE_DISK; +} + +static sector_t iblock_get_blocks(struct se_device *dev) +{ + struct iblock_dev *ibd = dev->dev_ptr; + struct block_device *bd = ibd->ibd_bd; + struct request_queue *q = bdev_get_queue(bd); + + return iblock_emulate_read_cap_with_block_size(dev, bd, q); +} + +static void iblock_bio_done(struct bio *bio, int err) +{ + struct se_task *task = bio->bi_private; + struct iblock_req *ibr = IBLOCK_REQ(task); + /* + * 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) { + printk(KERN_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_inc(); + bio_put(bio); + /* + * Wait to complete the task until the last bio as completed. + */ + if (!(atomic_dec_and_test(&ibr->ib_bio_cnt))) + return; + + ibr->ib_bio = NULL; + transport_complete_task(task, 0); + return; + } + DEBUG_IBLOCK("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n", + task, bio, task->task_lba, bio->bi_sector, err); + /* + * bio_put() will call iblock_bio_destructor() to release the bio back + * to ibr->ib_bio_set. + */ + bio_put(bio); + /* + * Wait to complete the task until the last bio as completed. + */ + if (!(atomic_dec_and_test(&ibr->ib_bio_cnt))) + return; + /* + * Return GOOD status for task if zero ib_bio_err_cnt exists. + */ + ibr->ib_bio = NULL; + transport_complete_task(task, (!atomic_read(&ibr->ib_bio_err_cnt))); +} + +static struct se_subsystem_api iblock_template = { + .name = "iblock", + .owner = THIS_MODULE, + .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV, + .map_task_SG = iblock_map_task_SG, + .attach_hba = iblock_attach_hba, + .detach_hba = iblock_detach_hba, + .allocate_virtdevice = iblock_allocate_virtdevice, + .create_virtdevice = iblock_create_virtdevice, + .free_device = iblock_free_device, + .dpo_emulated = iblock_emulated_dpo, + .fua_write_emulated = iblock_emulated_fua_write, + .fua_read_emulated = iblock_emulated_fua_read, + .write_cache_emulated = iblock_emulated_write_cache, + .alloc_task = iblock_alloc_task, + .do_task = iblock_do_task, + .do_discard = iblock_do_discard, + .do_sync_cache = iblock_emulate_sync_cache, + .free_task = iblock_free_task, + .check_configfs_dev_params = iblock_check_configfs_dev_params, + .set_configfs_dev_params = iblock_set_configfs_dev_params, + .show_configfs_dev_params = iblock_show_configfs_dev_params, + .get_cdb = iblock_get_cdb, + .get_device_rev = iblock_get_device_rev, + .get_device_type = iblock_get_device_type, + .get_blocks = iblock_get_blocks, +}; + +static int __init iblock_module_init(void) +{ + return transport_subsystem_register(&iblock_template); +} + +static void iblock_module_exit(void) +{ + transport_subsystem_release(&iblock_template); +} + +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); |