From 015487b89f27d91d95a056cdc3c85e6c729bff12 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Mon, 13 Feb 2012 16:18:17 -0800 Subject: target: Untangle front-end and back-end meanings of max_sectors attribute se_dev_attrib.max_sectors currently has two independent meanings: - It is reported in the block limits VPD page as the maximum transfer length, ie the largest IO that the front-end (fabric) can handle. Also the target core doesn't enforce this maximum transfer length. - It is used to hold the size of the largest IO that the back-end can handle, so we know when to split SCSI commands into multiple tasks. Fix this by adding a new se_dev_attrib.fabric_max_sectors to hold the maximum transfer length, and checking incoming IOs against that limit. Signed-off-by: Roland Dreier Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_device.c | 65 +++++++++++++++++++++++++++++++++---- 1 file changed, 59 insertions(+), 6 deletions(-) (limited to 'drivers/target/target_core_device.c') diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 0b25b50900e..27da4e4e07c 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -889,10 +889,15 @@ void se_dev_set_default_attribs( limits->logical_block_size); dev->se_sub_dev->se_dev_attrib.max_sectors = limits->max_sectors; /* - * Set optimal_sectors from max_sectors, which can be lowered via - * configfs. + * Set fabric_max_sectors, which is reported in block limits + * VPD page (B0h). */ - dev->se_sub_dev->se_dev_attrib.optimal_sectors = limits->max_sectors; + dev->se_sub_dev->se_dev_attrib.fabric_max_sectors = DA_FABRIC_MAX_SECTORS; + /* + * Set optimal_sectors from fabric_max_sectors, which can be + * lowered via configfs. + */ + dev->se_sub_dev->se_dev_attrib.optimal_sectors = DA_FABRIC_MAX_SECTORS; /* * queue_depth is based on subsystem plugin dependent requirements. */ @@ -1224,6 +1229,54 @@ int se_dev_set_max_sectors(struct se_device *dev, u32 max_sectors) return 0; } +int se_dev_set_fabric_max_sectors(struct se_device *dev, u32 fabric_max_sectors) +{ + if (atomic_read(&dev->dev_export_obj.obj_access_count)) { + pr_err("dev[%p]: Unable to change SE Device" + " fabric_max_sectors while dev_export_obj: %d count exists\n", + dev, atomic_read(&dev->dev_export_obj.obj_access_count)); + return -EINVAL; + } + if (!fabric_max_sectors) { + pr_err("dev[%p]: Illegal ZERO value for" + " fabric_max_sectors\n", dev); + return -EINVAL; + } + if (fabric_max_sectors < DA_STATUS_MAX_SECTORS_MIN) { + pr_err("dev[%p]: Passed fabric_max_sectors: %u less than" + " DA_STATUS_MAX_SECTORS_MIN: %u\n", dev, fabric_max_sectors, + DA_STATUS_MAX_SECTORS_MIN); + return -EINVAL; + } + if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) { + if (fabric_max_sectors > dev->se_sub_dev->se_dev_attrib.hw_max_sectors) { + pr_err("dev[%p]: Passed fabric_max_sectors: %u" + " greater than TCM/SE_Device max_sectors:" + " %u\n", dev, fabric_max_sectors, + dev->se_sub_dev->se_dev_attrib.hw_max_sectors); + return -EINVAL; + } + } else { + if (fabric_max_sectors > DA_STATUS_MAX_SECTORS_MAX) { + pr_err("dev[%p]: Passed fabric_max_sectors: %u" + " greater than DA_STATUS_MAX_SECTORS_MAX:" + " %u\n", dev, fabric_max_sectors, + DA_STATUS_MAX_SECTORS_MAX); + return -EINVAL; + } + } + /* + * Align max_sectors down to PAGE_SIZE to follow transport_allocate_data_tasks() + */ + fabric_max_sectors = se_dev_align_max_sectors(fabric_max_sectors, + dev->se_sub_dev->se_dev_attrib.block_size); + + dev->se_sub_dev->se_dev_attrib.fabric_max_sectors = fabric_max_sectors; + pr_debug("dev[%p]: SE Device max_sectors changed to %u\n", + dev, fabric_max_sectors); + return 0; +} + int se_dev_set_optimal_sectors(struct se_device *dev, u32 optimal_sectors) { if (atomic_read(&dev->dev_export_obj.obj_access_count)) { @@ -1237,10 +1290,10 @@ int se_dev_set_optimal_sectors(struct se_device *dev, u32 optimal_sectors) " changed for TCM/pSCSI\n", dev); return -EINVAL; } - if (optimal_sectors > dev->se_sub_dev->se_dev_attrib.max_sectors) { + if (optimal_sectors > dev->se_sub_dev->se_dev_attrib.fabric_max_sectors) { pr_err("dev[%p]: Passed optimal_sectors %u cannot be" - " greater than max_sectors: %u\n", dev, - optimal_sectors, dev->se_sub_dev->se_dev_attrib.max_sectors); + " greater than fabric_max_sectors: %u\n", dev, + optimal_sectors, dev->se_sub_dev->se_dev_attrib.fabric_max_sectors); return -EINVAL; } -- cgit v1.2.3