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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /drivers/target/target_core_iblock.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'drivers/target/target_core_iblock.c')
-rw-r--r-- | drivers/target/target_core_iblock.c | 694 |
1 files changed, 694 insertions, 0 deletions
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c new file mode 100644 index 00000000..2ec299e8 --- /dev/null +++ b/drivers/target/target_core_iblock.c @@ -0,0 +1,694 @@ +/******************************************************************************* + * 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/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.h> +#include <scsi/scsi_host.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 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) +{ + pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on" + " Generic Target Core Stack %s\n", hba->hba_id, + IBLOCK_VERSION, TARGET_CORE_MOD_VERSION); + return 0; +} + +static void iblock_detach_hba(struct se_hba *hba) +{ +} + +static void *iblock_allocate_virtdevice(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; +} + +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; + int ret = -EINVAL; + + if (!ib_dev) { + pr_err("Unable to locate struct iblock_dev parameter\n"); + return ERR_PTR(ret); + } + memset(&dev_limits, 0, sizeof(struct se_dev_limits)); + + 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"); + return ERR_PTR(-ENOMEM); + } + pr_debug("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. + */ + pr_debug( "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 (IS_ERR(bd)) { + ret = PTR_ERR(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 = UINT_MAX; + limits->max_sectors = UINT_MAX; + dev_limits.hw_queue_depth = q->nr_requests; + dev_limits.queue_depth = q->nr_requests; + + ib_dev->ibd_bd = bd; + + dev = transport_add_device_to_core_hba(hba, + &iblock_template, se_dev, dev_flags, ib_dev, + &dev_limits, "IBLOCK", IBLOCK_VERSION); + if (!dev) + goto failed; + + /* + * 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->se_sub_dev->se_dev_attrib.max_unmap_lba_count = + q->limits.max_discard_sectors; + /* + * Currently hardcoded to 1 in Linux/SCSI code.. + */ + dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count = 1; + dev->se_sub_dev->se_dev_attrib.unmap_granularity = + q->limits.discard_granularity >> 9; + dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment = + q->limits.discard_alignment; + + pr_debug("IBLOCK: BLOCK Discard support available," + " disabled by default\n"); + } + + if (blk_queue_nonrot(q)) + dev->se_sub_dev->se_dev_attrib.is_nonrot = 1; + + 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; + return ERR_PTR(ret); +} + +static void iblock_free_device(void *p) +{ + struct iblock_dev *ib_dev = p; + + 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); + 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(unsigned char *cdb) +{ + struct iblock_req *ib_req; + + ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); + if (!ib_req) { + pr_err("Unable to allocate memory for struct iblock_req\n"); + return NULL; + } + + atomic_set(&ib_req->pending, 1); + 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->se_sub_dev->se_dev_attrib.block_size) + return blocks_long; + + switch (block_size) { + case 4096: + switch (dev->se_sub_dev->se_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->se_sub_dev->se_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->se_sub_dev->se_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->se_sub_dev->se_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_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) + transport_complete_sync_cache(cmd, err == 0); + bio_put(bio); +} + +/* + * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must + * always flush the whole cache. + */ +static void iblock_emulate_sync_cache(struct se_task *task) +{ + struct se_cmd *cmd = task->task_se_cmd; + struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr; + 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) + transport_complete_sync_cache(cmd, 1); + + 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); +} + +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) +{ + kfree(IBLOCK_REQ(task)); +} + +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, *arg_p, *opts; + substring_t args[MAX_OPT_ARGS]; + int ret = 0, token; + + 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; + } + arg_p = match_strdup(&args[0]); + if (!arg_p) { + ret = -ENOMEM; + break; + } + snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN, + "%s", arg_p); + kfree(arg_p); + pr_debug("IBLOCK: Referencing UDEV path: %s\n", + ib_dev->ibd_udev_path); + ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH; + break; + case Opt_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)) { + pr_err("Missing udev_path= parameters for IBLOCK\n"); + return -EINVAL; + } + + 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", + MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ? + "" : (bd->bd_holder == ibd) ? + "CLAIMED: IBLOCK" : "CLAIMED: OS"); + } else { + bl += sprintf(b + bl, "Major: 0 Minor: 0\n"); + } + + return bl; +} + +static void iblock_bio_destructor(struct bio *bio) +{ + struct se_task *task = bio->bi_private; + struct iblock_dev *ib_dev = task->task_se_cmd->se_dev->dev_ptr; + + bio_free(bio, ib_dev->ibd_bio_set); +} + +static struct bio * +iblock_get_bio(struct se_task *task, sector_t lba, u32 sg_num) +{ + struct iblock_dev *ib_dev = task->task_se_cmd->se_dev->dev_ptr; + struct iblock_req *ib_req = IBLOCK_REQ(task); + 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; + } + + pr_debug("Allocated bio: %p task_sg_nents: %u using ibd_bio_set:" + " %p\n", bio, task->task_sg_nents, ib_dev->ibd_bio_set); + pr_debug("Allocated bio: %p task_size: %u\n", bio, task->task_size); + + bio->bi_bdev = ib_dev->ibd_bd; + bio->bi_private = task; + bio->bi_destructor = iblock_bio_destructor; + bio->bi_end_io = &iblock_bio_done; + bio->bi_sector = lba; + atomic_inc(&ib_req->pending); + + pr_debug("Set bio->bi_sector: %llu\n", (unsigned long long)bio->bi_sector); + pr_debug("Set ib_req->pending: %d\n", atomic_read(&ib_req->pending)); + 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 int iblock_do_task(struct se_task *task) +{ + struct se_cmd *cmd = task->task_se_cmd; + struct se_device *dev = cmd->se_dev; + struct iblock_req *ibr = IBLOCK_REQ(task); + struct bio *bio; + struct bio_list list; + struct scatterlist *sg; + u32 i, sg_num = task->task_sg_nents; + sector_t block_lba; + unsigned bio_cnt; + 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->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 || + (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 && + (cmd->se_cmd_flags & SCF_FUA))) + rw = WRITE_FUA; + else + rw = WRITE; + } else { + rw = READ; + } + + /* + * Do starting conversion up from non 512-byte blocksize with + * struct se_task SCSI blocksize into Linux/Block 512 units for BIO. + */ + if (dev->se_sub_dev->se_dev_attrib.block_size == 4096) + block_lba = (task->task_lba << 3); + else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048) + block_lba = (task->task_lba << 2); + else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024) + block_lba = (task->task_lba << 1); + else if (dev->se_sub_dev->se_dev_attrib.block_size == 512) + block_lba = task->task_lba; + else { + pr_err("Unsupported SCSI -> BLOCK LBA conversion:" + " %u\n", dev->se_sub_dev->se_dev_attrib.block_size); + cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + return -ENOSYS; + } + + bio = iblock_get_bio(task, block_lba, sg_num); + if (!bio) { + cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + return -ENOMEM; + } + + bio_list_init(&list); + bio_list_add(&list, bio); + bio_cnt = 1; + + for_each_sg(task->task_sg, sg, task->task_sg_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(task, block_lba, sg_num); + if (!bio) + goto fail; + bio_list_add(&list, bio); + bio_cnt++; + } + + /* Always in 512 byte units for Linux/Block */ + block_lba += sg->length >> IBLOCK_LBA_SHIFT; + sg_num--; + } + + iblock_submit_bios(&list, rw); + + if (atomic_dec_and_test(&ibr->pending)) { + transport_complete_task(task, + !atomic_read(&ibr->ib_bio_err_cnt)); + } + return 0; + +fail: + while ((bio = bio_list_pop(&list))) + bio_put(bio); + cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + return -ENOMEM; +} + +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) { + 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_inc(); + } + + bio_put(bio); + + if (!atomic_dec_and_test(&ibr->pending)) + return; + + pr_debug("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n", + task, bio, task->task_lba, + (unsigned long long)bio->bi_sector, err); + + 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, + .write_cache_emulated = 1, + .fua_write_emulated = 1, + .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, + .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_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); |