From 0dfa1c5da3e4b6849d40f4c3fc43212b6359a09d Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Mon, 17 Dec 2012 09:53:35 +0100 Subject: target: Export SPC inquiry emulation Some target drivers might need to access the inquiry data directly, without sending out the actual command. So export these functions. Signed-off-by: Hannes Reinecke Cc: Nicholas Bellinger Signed-off-by: Nicholas Bellinger --- include/target/target_core_backend.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/target/target_core_backend.h') diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h index 507910992c59..819b0fc45215 100644 --- a/include/target/target_core_backend.h +++ b/include/target/target_core_backend.h @@ -53,6 +53,8 @@ void target_complete_cmd(struct se_cmd *, u8); sense_reason_t spc_parse_cdb(struct se_cmd *cmd, unsigned int *size); sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd); sector_t spc_get_write_same_sectors(struct se_cmd *cmd); +sense_reason_t spc_emulate_inquiry_std(struct se_cmd *, unsigned char *); +sense_reason_t spc_emulate_evpd_83(struct se_cmd *, unsigned char *); sense_reason_t sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops); u32 sbc_get_device_rev(struct se_device *dev); -- cgit v1.2.3 From d0c8b259f8970d39354c1966853363345d401330 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Tue, 29 Jan 2013 22:10:06 -0800 Subject: target/iblock: Use backend REQ_FLUSH hint for WriteCacheEnabled status This patch allows IBLOCK to check block hints in request_queue->flush_flags when reporting current backend device WriteCacheEnabled status to a remote SCSI initiator port. This is done via a se_subsystem_api->get_write_cache() call instead of a backend se_device creation time flag, as we expect REQ_FLUSH bits to possibly change from an underlying blk_queue_flush() by the SCSI disk driver, or internal raw struct block_device driver usage. Also go ahead and update iblock_execute_rw() bio I/O path code to use REQ_FLUSH + REQ_FUA hints when determining WRITE_FUA usage, and make SPC emulation code use a spc_check_dev_wce() helper to handle both types of cases for virtual backend subsystem drivers. (asias: Drop unnecessary comparsion operators) Reported-by: majianpeng Cc: majianpeng Cc: Christoph Hellwig Cc: Jens Axboe Cc: James Bottomley Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_device.c | 6 ++++++ drivers/target/target_core_iblock.c | 31 +++++++++++++++++++++++-------- drivers/target/target_core_spc.c | 21 ++++++++++++++++++--- include/target/target_core_backend.h | 1 + 4 files changed, 48 insertions(+), 11 deletions(-) (limited to 'include/target/target_core_backend.h') diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index f2aa7543d20a..d10cbed23472 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -772,6 +772,12 @@ int se_dev_set_emulate_write_cache(struct se_device *dev, int flag) pr_err("emulate_write_cache not supported for pSCSI\n"); return -EINVAL; } + if (dev->transport->get_write_cache) { + pr_warn("emulate_write_cache cannot be changed when underlying" + " HW reports WriteCacheEnabled, ignoring request\n"); + return 0; + } + dev->dev_attrib.emulate_write_cache = flag; pr_debug("dev[%p]: SE Device WRITE_CACHE_EMULATION flag: %d\n", dev, dev->dev_attrib.emulate_write_cache); diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c index b526d23dcd4f..2f74e17ad3e6 100644 --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -154,6 +154,7 @@ static int iblock_configure_device(struct se_device *dev) if (blk_queue_nonrot(q)) dev->dev_attrib.is_nonrot = 1; + return 0; out_free_bioset: @@ -654,20 +655,24 @@ iblock_execute_rw(struct se_cmd *cmd) u32 sg_num = sgl_nents; sector_t block_lba; unsigned bio_cnt; - int rw; + 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 data to disk if we pretend to not have a volatile - * write cache, or the initiator set the Force Unit Access bit. + * Force writethrough using WRITE_FUA if a volatile write cache + * is not enabled, or if initiator set the Force Unit Access bit. */ - if (dev->dev_attrib.emulate_write_cache == 0 || - (dev->dev_attrib.emulate_fua_write > 0 && - (cmd->se_cmd_flags & SCF_FUA))) - rw = WRITE_FUA; - else + 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 = READ; } @@ -774,6 +779,15 @@ 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", @@ -790,6 +804,7 @@ 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_write_cache = iblock_get_write_cache, }; static int __init iblock_module_init(void) diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index fa2447004006..803339516fb9 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -407,16 +407,31 @@ 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) { + struct se_device *dev = cmd->se_dev; + buf[3] = 0x3c; /* Set HEADSUP, ORDSUP, SIMPSUP */ buf[5] = 0x07; /* If WriteCache emulation is enabled, set V_SUP */ - if (cmd->se_dev->dev_attrib.emulate_write_cache > 0) + if (spc_check_dev_wce(dev)) buf[6] = 0x01; return 0; } @@ -766,7 +781,7 @@ static int spc_modesense_caching(struct se_device *dev, u8 pc, u8 *p) if (pc == 1) goto out; - if (dev->dev_attrib.emulate_write_cache > 0) + if (spc_check_dev_wce(dev)) p[2] = 0x04; /* Write Cache Enable */ p[12] = 0x20; /* Disabled Read Ahead */ @@ -878,7 +893,7 @@ 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 ((dev->dev_attrib.emulate_write_cache > 0) && + if ((spc_check_dev_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 819b0fc45215..f9a80169775d 100644 --- a/include/target/target_core_backend.h +++ b/include/target/target_core_backend.h @@ -35,6 +35,7 @@ struct se_subsystem_api { u32 (*get_device_type)(struct se_device *); sector_t (*get_blocks)(struct se_device *); unsigned char *(*get_sense_buffer)(struct se_cmd *); + bool (*get_write_cache)(struct se_device *); }; struct sbc_ops { -- cgit v1.2.3 From 972b29c8f86093f44e1d781588bd5c5faae3d8e3 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Fri, 22 Feb 2013 09:52:57 -0800 Subject: target: Rename spc_get_write_same_sectors -> sbc_get_write_same_sectors Trivial, but WRITE SAME is an SBC command so it seems strange for a related function (defined in target_core_sbc.c) to be in the spc_ namespace. Signed-off-by: Roland Dreier Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_file.c | 2 +- drivers/target/target_core_iblock.c | 4 ++-- drivers/target/target_core_sbc.c | 6 +++--- include/target/target_core_backend.h | 2 +- 4 files changed, 7 insertions(+), 7 deletions(-) (limited to 'include/target/target_core_backend.h') diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c index 94383a56bd74..ca36a38eb274 100644 --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -381,7 +381,7 @@ fd_execute_write_same(struct se_cmd *cmd) struct scatterlist *sg; struct iovec *iov; mm_segment_t old_fs; - sector_t nolb = spc_get_write_same_sectors(cmd); + sector_t nolb = sbc_get_write_same_sectors(cmd); loff_t pos = cmd->t_task_lba * se_dev->dev_attrib.block_size; unsigned int len, len_tmp, iov_num; int i, rc; diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c index facee5f74fa4..c73f4a950e23 100644 --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -473,7 +473,7 @@ iblock_execute_write_same_unmap(struct se_cmd *cmd) int rc; rc = blkdev_issue_discard(ib_dev->ibd_bd, cmd->t_task_lba, - spc_get_write_same_sectors(cmd), GFP_KERNEL, 0); + sbc_get_write_same_sectors(cmd), GFP_KERNEL, 0); if (rc < 0) { pr_warn("blkdev_issue_discard() failed: %d\n", rc); return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; @@ -491,7 +491,7 @@ iblock_execute_write_same(struct se_cmd *cmd) struct bio *bio; struct bio_list list; sector_t block_lba = cmd->t_task_lba; - sector_t sectors = spc_get_write_same_sectors(cmd); + sector_t sectors = sbc_get_write_same_sectors(cmd); sg = &cmd->t_data_sg[0]; diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 170f1f75d2d8..290230de2c53 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -105,7 +105,7 @@ sbc_emulate_readcapacity_16(struct se_cmd *cmd) return 0; } -sector_t spc_get_write_same_sectors(struct se_cmd *cmd) +sector_t sbc_get_write_same_sectors(struct se_cmd *cmd) { u32 num_blocks; @@ -126,7 +126,7 @@ sector_t spc_get_write_same_sectors(struct se_cmd *cmd) return cmd->se_dev->transport->get_blocks(cmd->se_dev) - cmd->t_task_lba + 1; } -EXPORT_SYMBOL(spc_get_write_same_sectors); +EXPORT_SYMBOL(sbc_get_write_same_sectors); static sense_reason_t sbc_emulate_noop(struct se_cmd *cmd) @@ -233,7 +233,7 @@ static inline unsigned long long transport_lba_64_ext(unsigned char *cdb) static sense_reason_t sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops) { - unsigned int sectors = spc_get_write_same_sectors(cmd); + unsigned int sectors = sbc_get_write_same_sectors(cmd); if ((flags[0] & 0x04) || (flags[0] & 0x02)) { pr_err("WRITE_SAME PBDATA and LBDATA" diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h index f9a80169775d..b128c20770bc 100644 --- a/include/target/target_core_backend.h +++ b/include/target/target_core_backend.h @@ -53,13 +53,13 @@ void target_complete_cmd(struct se_cmd *, u8); sense_reason_t spc_parse_cdb(struct se_cmd *cmd, unsigned int *size); sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd); -sector_t spc_get_write_same_sectors(struct se_cmd *cmd); sense_reason_t spc_emulate_inquiry_std(struct se_cmd *, unsigned char *); sense_reason_t spc_emulate_evpd_83(struct se_cmd *, unsigned char *); sense_reason_t sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops); u32 sbc_get_device_rev(struct se_device *dev); u32 sbc_get_device_type(struct se_device *dev); +sector_t sbc_get_write_same_sectors(struct se_cmd *cmd); void transport_set_vpd_proto_id(struct t10_vpd *, unsigned char *); int transport_set_vpd_assoc(struct t10_vpd *, unsigned char *); -- cgit v1.2.3