From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch adds the TCM/IBLOCK subsystem plugin for accessing struct block_device
with an emulated SPC-3 control path from Linux/BLOCK code using struct bio. The
also includes WriteCache and FUA Write emulation to struct block_device using
block/blk-barrier.c:blkdev_issue_flush()
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_iblock.c | 808 +++++++++++++++++++++++++++++++++++
drivers/target/target_core_iblock.h | 40 ++
2 files changed, 848 insertions(+), 0 deletions(-)
create mode 100644 drivers/target/target_core_iblock.c
create mode 100644 drivers/target/target_core_iblock.h
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
new file mode 100644
index 0000000..e99bfc2
--- /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@xxxxxxxxxx>
+ *
+ * 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 = open_bdev_exclusive(ib_dev->ibd_udev_path,
+ FMODE_WRITE|FMODE_READ, 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;
+
+ close_bdev_exclusive(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ);
+ 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@xxxxxxxxxxxxxxx");
+MODULE_LICENSE("GPL");
+
+module_init(iblock_module_init);
+module_exit(iblock_module_exit);
diff --git a/drivers/target/target_core_iblock.h b/drivers/target/target_core_iblock.h
new file mode 100644
index 0000000..64c1f4d
--- /dev/null
+++ b/drivers/target/target_core_iblock.h
@@ -0,0 +1,40 @@
+#ifndef TARGET_CORE_IBLOCK_H
+#define TARGET_CORE_IBLOCK_H
+
+#define IBLOCK_VERSION "4.0"
+
+#define IBLOCK_HBA_QUEUE_DEPTH 512
+#define IBLOCK_DEVICE_QUEUE_DEPTH 32
+#define IBLOCK_MAX_DEVICE_QUEUE_DEPTH 128
+#define IBLOCK_MAX_CDBS 16
+#define IBLOCK_LBA_SHIFT 9
+
+struct iblock_req {
+ struct se_task ib_task;
+ unsigned char ib_scsi_cdb[TCM_MAX_COMMAND_SIZE];
+ atomic_t ib_bio_cnt;
+ atomic_t ib_bio_err_cnt;
+ struct bio *ib_bio;
+ struct iblock_dev *ib_dev;
+} ____cacheline_aligned;
+
+#define IBDF_HAS_UDEV_PATH 0x01
+#define IBDF_HAS_FORCE 0x02
+
+struct iblock_dev {
+ unsigned char ibd_udev_path[SE_UDEV_PATH_LEN];
+ int ibd_force;
+ int ibd_major;
+ int ibd_minor;
+ u32 ibd_depth;
+ u32 ibd_flags;
+ struct bio_set *ibd_bio_set;
+ struct block_device *ibd_bd;
+ struct iblock_hba *ibd_host;
+} ____cacheline_aligned;
+
+struct iblock_hba {
+ int iblock_host_id;
+} ____cacheline_aligned;
+
+#endif /* TARGET_CORE_IBLOCK_H */
--
1.7.3.4
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
