From e6f41633cb79b55ead84b023c02035322c7827e7 Mon Sep 17 00:00:00 2001 From: Jamie Pocas Date: Sun, 29 Nov 2015 14:44:57 -0800 Subject: [PATCH] target/sbc: Add LBPRZ attribute + control CDB emulation This change sets the LBPRZ flag in EVPD page b2h and READ CAPACITY (16) based on a new unmap_zeroes_data device attribute. This flag is set automatically for iblock based on underlying block device queue's discard_zeroes_data flag. Signed-off-by: Jamie Pocas Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_configfs.c | 36 +++++++++++++++++++++++++++ drivers/target/target_core_device.c | 2 ++ drivers/target/target_core_iblock.c | 2 ++ drivers/target/target_core_sbc.c | 10 +++++++- drivers/target/target_core_spc.c | 12 +++++++++ include/target/target_core_base.h | 3 +++ 6 files changed, 64 insertions(+), 1 deletion(-) diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c index 2e47fe68e4ea..affe4c393ebc 100644 --- a/drivers/target/target_core_configfs.c +++ b/drivers/target/target_core_configfs.c @@ -499,6 +499,7 @@ DEF_CONFIGFS_ATTRIB_SHOW(max_unmap_lba_count); DEF_CONFIGFS_ATTRIB_SHOW(max_unmap_block_desc_count); DEF_CONFIGFS_ATTRIB_SHOW(unmap_granularity); DEF_CONFIGFS_ATTRIB_SHOW(unmap_granularity_alignment); +DEF_CONFIGFS_ATTRIB_SHOW(unmap_zeroes_data); DEF_CONFIGFS_ATTRIB_SHOW(max_write_same_len); #define DEF_CONFIGFS_ATTRIB_STORE_U32(_name) \ @@ -866,6 +867,39 @@ static ssize_t emulate_rest_reord_store(struct config_item *item, return count; } +static ssize_t unmap_zeroes_data_store(struct config_item *item, + const char *page, size_t count) +{ + struct se_dev_attrib *da = to_attrib(item); + bool flag; + int ret; + + ret = strtobool(page, &flag); + if (ret < 0) + return ret; + + if (da->da_dev->export_count) { + pr_err("dev[%p]: Unable to change SE Device" + " unmap_zeroes_data while export_count is %d\n", + da->da_dev, da->da_dev->export_count); + return -EINVAL; + } + /* + * We expect this value to be non-zero when generic Block Layer + * Discard supported is detected iblock_configure_device(). + */ + if (flag && !da->max_unmap_block_desc_count) { + pr_err("dev[%p]: Thin Provisioning LBPRZ will not be set" + " because max_unmap_block_desc_count is zero\n", + da->da_dev); + return -ENOSYS; + } + da->unmap_zeroes_data = flag; + pr_debug("dev[%p]: SE Device Thin Provisioning LBPRZ bit: %d\n", + da->da_dev, flag); + return 0; +} + /* * Note, this can only be called on unexported SE Device Object. */ @@ -998,6 +1032,7 @@ CONFIGFS_ATTR(, max_unmap_lba_count); CONFIGFS_ATTR(, max_unmap_block_desc_count); CONFIGFS_ATTR(, unmap_granularity); CONFIGFS_ATTR(, unmap_granularity_alignment); +CONFIGFS_ATTR(, unmap_zeroes_data); CONFIGFS_ATTR(, max_write_same_len); /* @@ -1034,6 +1069,7 @@ struct configfs_attribute *sbc_attrib_attrs[] = { &attr_max_unmap_block_desc_count, &attr_unmap_granularity, &attr_unmap_granularity_alignment, + &attr_unmap_zeroes_data, &attr_max_write_same_len, NULL, }; diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 88ea4e4f124b..cacd97a8cbd0 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -813,6 +813,8 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name) dev->dev_attrib.unmap_granularity = DA_UNMAP_GRANULARITY_DEFAULT; dev->dev_attrib.unmap_granularity_alignment = DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT; + dev->dev_attrib.unmap_zeroes_data = + DA_UNMAP_ZEROES_DATA_DEFAULT; dev->dev_attrib.max_write_same_len = DA_MAX_WRITE_SAME_LEN; xcopy_lun = &dev->xcopy_lun; diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c index f29c69120054..e77d15000caa 100644 --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -138,6 +138,8 @@ static int iblock_configure_device(struct se_device *dev) q->limits.discard_granularity >> 9; dev->dev_attrib.unmap_granularity_alignment = q->limits.discard_alignment; + dev->dev_attrib.unmap_zeroes_data = + q->limits.discard_zeroes_data; pr_debug("IBLOCK: BLOCK Discard support available," " disabled by default\n"); diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 0b4b2a67d9f9..b83ac3766fe7 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -141,9 +141,17 @@ sbc_emulate_readcapacity_16(struct se_cmd *cmd) * 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) + if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) { buf[14] |= 0x80; + /* + * LBPRZ signifies that zeroes will be read back from an LBA after + * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2) + */ + if (dev->dev_attrib.unmap_zeroes_data) + buf[14] |= 0x40; + } + rbuf = transport_kmap_data_sg(cmd); if (rbuf) { memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length)); diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index 9413e1a949e5..0aa47babd16c 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -635,6 +635,18 @@ spc_emulate_evpd_b2(struct se_cmd *cmd, unsigned char *buf) if (dev->dev_attrib.emulate_tpws != 0) buf[5] |= 0x40 | 0x20; + /* + * The unmap_zeroes_data set means that the underlying device supports + * REQ_DISCARD and has the discard_zeroes_data bit set. This satisfies + * the SBC requirements for LBPRZ, meaning that a subsequent read + * will return zeroes after an UNMAP or WRITE SAME (16) to an LBA + * See sbc4r36 6.6.4. + */ + if (((dev->dev_attrib.emulate_tpu != 0) || + (dev->dev_attrib.emulate_tpws != 0)) && + (dev->dev_attrib.unmap_zeroes_data != 0)) + buf[5] |= 0x04; + return 0; } diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 0a2c74008e53..dc8b796dbcc7 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -63,6 +63,8 @@ #define DA_UNMAP_GRANULARITY_DEFAULT 0 /* Default unmap_granularity_alignment */ #define DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT 0 +/* Default unmap_zeroes_data */ +#define DA_UNMAP_ZEROES_DATA_DEFAULT 0 /* Default max_write_same_len, disabled by default */ #define DA_MAX_WRITE_SAME_LEN 0 /* Use a model alias based on the configfs backend device name */ @@ -674,6 +676,7 @@ struct se_dev_attrib { int force_pr_aptpl; int is_nonrot; int emulate_rest_reord; + int unmap_zeroes_data; u32 hw_block_size; u32 block_size; u32 hw_max_sectors; -- 2.30.2