/******************************************************************************* * Filename: target_core_iblock.c * * This file contains the Storage Engine <-> Linux BlockIO transport * specific functions. * * (c) Copyright 2003-2012 RisingTide Systems LLC. * * 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" #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 struct se_subsystem_api iblock_template; /* 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 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; 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 = UINT_MAX; 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; return 0; out_free_bioset: bioset_free(ib_dev->ibd_bio_set); ib_dev->ibd_bio_set = NULL; out: return ret; } 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); kfree(ib_dev); } 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_inc(); } 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_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_do_unmap(struct se_cmd *cmd, void *priv, sector_t lba, sector_t nolb) { struct block_device *bdev = priv; 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_unmap(struct se_cmd *cmd) { struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; return sbc_execute_unmap(cmd, iblock_do_unmap, bdev); } static sense_reason_t iblock_execute_write_same_unmap(struct se_cmd *cmd) { struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; sector_t lba = cmd->t_task_lba; sector_t nolb = sbc_get_write_same_sectors(cmd); int ret; ret = iblock_do_unmap(cmd, bdev, lba, nolb); if (ret) return ret; target_complete_cmd(cmd, GOOD); 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); 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 = strict_strtoul(arg_p, 0, &tmp_readonly); kfree(arg_p); if (ret < 0) { pr_err("strict_strtoul() 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 sense_reason_t iblock_execute_rw(struct se_cmd *cmd) { struct scatterlist *sgl = cmd->t_data_sg; u32 sgl_nents = cmd->t_data_nents; enum dma_data_direction data_direction = cmd->data_direction; struct se_device *dev = cmd->se_dev; struct iblock_req *ibr; struct bio *bio; 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_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--; } 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 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_write_same_unmap = iblock_execute_write_same_unmap, .execute_unmap = iblock_execute_unmap, }; static sense_reason_t iblock_parse_cdb(struct se_cmd *cmd) { return sbc_parse_cdb(cmd, &iblock_sbc_ops); } 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 struct se_subsystem_api iblock_template = { .name = "iblock", .inquiry_prod = "IBLOCK", .inquiry_rev = IBLOCK_VERSION, .owner = THIS_MODULE, .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV, .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_write_cache = iblock_get_write_cache, }; static int __init iblock_module_init(void) { return transport_subsystem_register(&iblock_template); } static void __exit 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);