From 9bc6548f372d8c829235095d91de99d8df79db6e Mon Sep 17 00:00:00 2001 From: Christophe Vu-Brugier Date: Thu, 19 Mar 2015 14:30:13 +0100 Subject: [PATCH] target: do not reject FUA CDBs when write cache is enabled but emulate_write_cache is 0 A check that rejects a CDB with FUA bit set if no write cache is emulated was added by the following commit: fde9f50 target: Add sanity checks for DPO/FUA bit usage The condition is as follows: if (!dev->dev_attrib.emulate_fua_write || !dev->dev_attrib.emulate_write_cache) However, this check is wrong if the backend device supports WCE but "emulate_write_cache" is disabled. This patch uses se_dev_check_wce() (previously named spc_check_dev_wce) to invoke transport->get_write_cache() if the device has a write cache or check the "emulate_write_cache" attribute otherwise. Reported-by: Christoph Hellwig Signed-off-by: Christophe Vu-Brugier Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_device.c | 12 ++++++++++++ drivers/target/target_core_sbc.c | 3 +-- drivers/target/target_core_spc.c | 19 +++---------------- include/target/target_core_backend.h | 1 + 4 files changed, 17 insertions(+), 18 deletions(-) diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 7fc5eae875de..79b4ec3ca2db 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -650,6 +650,18 @@ static u32 se_dev_align_max_sectors(u32 max_sectors, u32 block_size) return aligned_max_sectors; } +bool se_dev_check_wce(struct se_device *dev) +{ + bool wce = false; + + if (dev->transport->get_write_cache) + wce = dev->transport->get_write_cache(dev); + else if (dev->dev_attrib.emulate_write_cache > 0) + wce = true; + + return wce; +} + int se_dev_set_max_unmap_lba_count( struct se_device *dev, u32 max_unmap_lba_count) diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 9a2f9d3a6e70..3e7297411110 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -708,8 +708,7 @@ sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb) } } if (cdb[1] & 0x8) { - if (!dev->dev_attrib.emulate_fua_write || - !dev->dev_attrib.emulate_write_cache) { + if (!dev->dev_attrib.emulate_fua_write || !se_dev_check_wce(dev)) { pr_err("Got CDB: 0x%02x with FUA bit set, but device" " does not advertise support for FUA write\n", cdb[0]); diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index 460e93109473..6c8bd6bc175c 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -454,19 +454,6 @@ check_scsi_name: } EXPORT_SYMBOL(spc_emulate_evpd_83); -static bool -spc_check_dev_wce(struct se_device *dev) -{ - bool wce = false; - - if (dev->transport->get_write_cache) - wce = dev->transport->get_write_cache(dev); - else if (dev->dev_attrib.emulate_write_cache > 0) - wce = true; - - return wce; -} - /* Extended INQUIRY Data VPD Page */ static sense_reason_t spc_emulate_evpd_86(struct se_cmd *cmd, unsigned char *buf) @@ -490,7 +477,7 @@ spc_emulate_evpd_86(struct se_cmd *cmd, unsigned char *buf) buf[5] = 0x07; /* If WriteCache emulation is enabled, set V_SUP */ - if (spc_check_dev_wce(dev)) + if (se_dev_check_wce(dev)) buf[6] = 0x01; /* If an LBA map is present set R_SUP */ spin_lock(&cmd->se_dev->t10_alua.lba_map_lock); @@ -897,7 +884,7 @@ static int spc_modesense_caching(struct se_cmd *cmd, u8 pc, u8 *p) if (pc == 1) goto out; - if (spc_check_dev_wce(dev)) + if (se_dev_check_wce(dev)) p[2] = 0x04; /* Write Cache Enable */ p[12] = 0x20; /* Disabled Read Ahead */ @@ -1009,7 +996,7 @@ static sense_reason_t spc_emulate_modesense(struct se_cmd *cmd) (cmd->se_deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY))) spc_modesense_write_protect(&buf[length], type); - if ((spc_check_dev_wce(dev)) && + if ((se_dev_check_wce(dev)) && (dev->dev_attrib.emulate_fua_write > 0)) spc_modesense_dpofua(&buf[length], type); diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h index db81c65b8f48..d61be7297b2c 100644 --- a/include/target/target_core_backend.h +++ b/include/target/target_core_backend.h @@ -111,6 +111,7 @@ void array_free(void *array, int n); void target_core_setup_sub_cits(struct se_subsystem_api *); /* attribute helpers from target_core_device.c for backend drivers */ +bool se_dev_check_wce(struct se_device *); int se_dev_set_max_unmap_lba_count(struct se_device *, u32); int se_dev_set_max_unmap_block_desc_count(struct se_device *, u32); int se_dev_set_unmap_granularity(struct se_device *, u32); -- 2.20.1