/******************************************************************************* * 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 * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "target_core_iblock.h" 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) { pr_err("Unable to allocate memory for" " struct iblock_hba\n"); return -ENOMEM; } ib_host->iblock_host_id = host_id; hba->hba_ptr = ib_host; 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); pr_debug("CORE_HBA[%d] - Attached iBlock HBA: %u to Generic\n", hba->hba_id, ib_host->iblock_host_id); return 0; } static void iblock_detach_hba(struct se_hba *hba) { struct iblock_hba *ib_host = hba->hba_ptr; pr_debug("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) { pr_err("Unable to allocate struct iblock_dev\n"); return NULL; } ib_dev->ibd_host = ib_host; 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)); /* * These settings need to be made tunable.. */ ib_dev->ibd_bio_set = bioset_create(32, 64); 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 = queue_max_hw_sectors(q); limits->max_sectors = queue_max_sectors(q); 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; 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->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->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, ",")) != 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 == (struct iblock_dev *)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; 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->ib_bio_cnt); pr_debug("Set bio->bi_sector: %llu\n", (unsigned long long)bio->bi_sector); pr_debug("Set ib_req->ib_bio_cnt: %d\n", atomic_read(&ib_req->ib_bio_cnt)); return bio; } 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 bio *bio; struct bio_list list; struct scatterlist *sg; u32 i, sg_num = task->task_sg_nents; sector_t block_lba; struct blk_plug plug; 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 && task->task_se_cmd->t_tasks_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); return PYX_TRANSPORT_LU_COMM_FAILURE; } bio = iblock_get_bio(task, block_lba, sg_num); if (!bio) return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES; bio_list_init(&list); bio_list_add(&list, bio); 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) { bio = iblock_get_bio(task, block_lba, sg_num); if (!bio) goto fail; bio_list_add(&list, bio); } /* Always in 512 byte units for Linux/Block */ block_lba += sg->length >> IBLOCK_LBA_SHIFT; sg_num--; } blk_start_plug(&plug); while ((bio = bio_list_pop(&list))) submit_bio(rw, bio); blk_finish_plug(&plug); return PYX_TRANSPORT_SENT_TO_TRANSPORT; fail: while ((bio = bio_list_pop(&list))) bio_put(bio); return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES; } 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->ib_bio_cnt)) 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);