From 7f7caf6aa74a4f4ad21ebe08bf23b594fce45ca7 Mon Sep 17 00:00:00 2001 From: Andy Grover Date: Mon, 11 Nov 2013 08:59:17 -0800 Subject: target: Pass through I/O topology for block backstores In addition to block size (already implemented), passing through alignment offset, logical-to-phys block exponent, I/O granularity and optimal I/O length will allow initiators to properly handle layout on LUNs with 4K block sizes. Tested with various weird values via scsi_debug module. One thing to look at with this patch is the new block limits values -- instead of granularity 1 optimal 8192, Lio will now be returning whatever the block device says, which may affect performance. Signed-off-by: Andy Grover Acked-by: Martin K. Petersen Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_iblock.c | 43 ++++++++++++++++++++++++++++++++++++ drivers/target/target_core_sbc.c | 12 +++++++++- drivers/target/target_core_spc.c | 11 +++++++-- include/target/target_core_backend.h | 5 +++++ 4 files changed, 68 insertions(+), 3 deletions(-) diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c index b9a3394fe479..c87959f12760 100644 --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -710,6 +710,45 @@ static sector_t iblock_get_blocks(struct se_device *dev) return iblock_emulate_read_cap_with_block_size(dev, bd, q); } +static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev) +{ + struct iblock_dev *ib_dev = IBLOCK_DEV(dev); + struct block_device *bd = ib_dev->ibd_bd; + int ret; + + ret = bdev_alignment_offset(bd); + if (ret == -1) + return 0; + + /* convert offset-bytes to offset-lbas */ + return ret / bdev_logical_block_size(bd); +} + +static unsigned int iblock_get_lbppbe(struct se_device *dev) +{ + struct iblock_dev *ib_dev = IBLOCK_DEV(dev); + struct block_device *bd = ib_dev->ibd_bd; + int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd); + + return ilog2(logs_per_phys); +} + +static unsigned int iblock_get_io_min(struct se_device *dev) +{ + struct iblock_dev *ib_dev = IBLOCK_DEV(dev); + struct block_device *bd = ib_dev->ibd_bd; + + return bdev_io_min(bd); +} + +static unsigned int iblock_get_io_opt(struct se_device *dev) +{ + struct iblock_dev *ib_dev = IBLOCK_DEV(dev); + struct block_device *bd = ib_dev->ibd_bd; + + return bdev_io_opt(bd); +} + static struct sbc_ops iblock_sbc_ops = { .execute_rw = iblock_execute_rw, .execute_sync_cache = iblock_execute_sync_cache, @@ -749,6 +788,10 @@ static struct se_subsystem_api iblock_template = { .show_configfs_dev_params = iblock_show_configfs_dev_params, .get_device_type = sbc_get_device_type, .get_blocks = iblock_get_blocks, + .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas, + .get_lbppbe = iblock_get_lbppbe, + .get_io_min = iblock_get_io_min, + .get_io_opt = iblock_get_io_opt, .get_write_cache = iblock_get_write_cache, }; diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 6c17295e8d7c..61a30f0d7583 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -105,12 +105,22 @@ sbc_emulate_readcapacity_16(struct se_cmd *cmd) buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff; buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff; buf[11] = dev->dev_attrib.block_size & 0xff; + + if (dev->transport->get_lbppbe) + buf[13] = dev->transport->get_lbppbe(dev) & 0x0f; + + if (dev->transport->get_alignment_offset_lbas) { + u16 lalba = dev->transport->get_alignment_offset_lbas(dev); + buf[14] = (lalba >> 8) & 0x3f; + buf[15] = lalba & 0xff; + } + /* * Set Thin Provisioning Enable bit following sbc3r22 in section * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled. */ if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) - buf[14] = 0x80; + buf[14] |= 0x80; rbuf = transport_kmap_data_sg(cmd); if (rbuf) { diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index 074539558a54..f89a86f29ee3 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -452,6 +452,7 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) struct se_device *dev = cmd->se_dev; u32 max_sectors; int have_tp = 0; + int opt, min; /* * Following spc3r22 section 6.5.3 Block Limits VPD page, when @@ -475,7 +476,10 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) /* * Set OPTIMAL TRANSFER LENGTH GRANULARITY */ - put_unaligned_be16(1, &buf[6]); + if (dev->transport->get_io_min && (min = dev->transport->get_io_min(dev))) + put_unaligned_be16(min / dev->dev_attrib.block_size, &buf[6]); + else + put_unaligned_be16(1, &buf[6]); /* * Set MAXIMUM TRANSFER LENGTH @@ -487,7 +491,10 @@ spc_emulate_evpd_b0(struct se_cmd *cmd, unsigned char *buf) /* * Set OPTIMAL TRANSFER LENGTH */ - put_unaligned_be32(dev->dev_attrib.optimal_sectors, &buf[12]); + if (dev->transport->get_io_opt && (opt = dev->transport->get_io_opt(dev))) + put_unaligned_be32(opt / dev->dev_attrib.block_size, &buf[12]); + else + put_unaligned_be32(dev->dev_attrib.optimal_sectors, &buf[12]); /* * Exit now if we don't support TP. diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h index 5ebe21cd5d1c..39e0114d70c5 100644 --- a/include/target/target_core_backend.h +++ b/include/target/target_core_backend.h @@ -34,6 +34,11 @@ struct se_subsystem_api { sense_reason_t (*parse_cdb)(struct se_cmd *cmd); u32 (*get_device_type)(struct se_device *); sector_t (*get_blocks)(struct se_device *); + sector_t (*get_alignment_offset_lbas)(struct se_device *); + /* lbppbe = logical blocks per physical block exponent. see SBC-3 */ + unsigned int (*get_lbppbe)(struct se_device *); + unsigned int (*get_io_min)(struct se_device *); + unsigned int (*get_io_opt)(struct se_device *); unsigned char *(*get_sense_buffer)(struct se_cmd *); bool (*get_write_cache)(struct se_device *); }; -- cgit v1.2.3-55-g7522