target: Remove max_sectors device attribute for modern se_task less code

This patch removes the original usage of dev_attr->max_sectors in favor of
dev_attr->hw_max_sectors that is now being enforced by target core from
within transport_generic_cmd_sequencer() for SCF_SCSI_DATA_SG_IO_CDB ops.

After the recent se_task removal patches from hch, this value for IBLOCK
backends being set via configfs by userspace from an saved max_sectors
value that is turning out to be problematic, so it makes sense to go ahead
and remove this now legacy attribute all-together.

This patch also continues to make se_dev_set_default_attribs() do
(sectors / block_size) alignment for what actually get used by
target_core_mod to be safe here, following the same alignment currently
used by fabric_max_sectors.

Reported-by: Andy Grover <agrover@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 4 insertions, 65 deletions

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index e621350feebc..5ad972856a8d 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -876,15 +876,12 @@ void se_dev_set_default_attribs(
         dev->se_sub_dev->se_dev_attrib.hw_block_size = limits->logical_block_size;
         dev->se_sub_dev->se_dev_attrib.block_size = limits->logical_block_size;
         /*
-         * max_sectors is based on subsystem plugin dependent requirements.
+         * Align max_hw_sectors down to PAGE_SIZE I/O transfers
          */
-        dev->se_sub_dev->se_dev_attrib.hw_max_sectors = limits->max_hw_sectors;
-        /*
-         * Align max_sectors down to PAGE_SIZE to follow transport_allocate_data_tasks()
-         */
-        limits->max_sectors = se_dev_align_max_sectors(limits->max_sectors,
+        limits->max_hw_sectors = se_dev_align_max_sectors(limits->max_hw_sectors,
                                                 limits->logical_block_size);
-        dev->se_sub_dev->se_dev_attrib.max_sectors = limits->max_sectors;
+        dev->se_sub_dev->se_dev_attrib.hw_max_sectors = limits->max_hw_sectors;
+
         /*
          * Set fabric_max_sectors, which is reported in block limits
          * VPD page (B0h).
@@ -1168,64 +1165,6 @@ int se_dev_set_queue_depth(struct se_device *dev, u32 queue_depth)
         return 0;
 }
 
-int se_dev_set_max_sectors(struct se_device *dev, u32 max_sectors)
-{
-        int force = 0; /* Force setting for VDEVS */
-
-        if (atomic_read(&dev->dev_export_obj.obj_access_count)) {
-                pr_err("dev[%p]: Unable to change SE Device"
-                        " max_sectors while dev_export_obj: %d count exists\n",
-                        dev, atomic_read(&dev->dev_export_obj.obj_access_count));
-                return -EINVAL;
-        }
-        if (!max_sectors) {
-                pr_err("dev[%p]: Illegal ZERO value for"
-                        " max_sectors\n", dev);
-                return -EINVAL;
-        }
-        if (max_sectors < DA_STATUS_MAX_SECTORS_MIN) {
-                pr_err("dev[%p]: Passed max_sectors: %u less than"
-                        " DA_STATUS_MAX_SECTORS_MIN: %u\n", dev, max_sectors,
-                                DA_STATUS_MAX_SECTORS_MIN);
-                return -EINVAL;
-        }
-        if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
-                if (max_sectors > dev->se_sub_dev->se_dev_attrib.hw_max_sectors) {
-                        pr_err("dev[%p]: Passed max_sectors: %u"
-                                " greater than TCM/SE_Device max_sectors:"
-                                " %u\n", dev, max_sectors,
-                                dev->se_sub_dev->se_dev_attrib.hw_max_sectors);
-                         return -EINVAL;
-                }
-        } else {
-                if (!force && (max_sectors >
-                                 dev->se_sub_dev->se_dev_attrib.hw_max_sectors)) {
-                        pr_err("dev[%p]: Passed max_sectors: %u"
-                                " greater than TCM/SE_Device max_sectors"
-                                ": %u, use force=1 to override.\n", dev,
-                                max_sectors, dev->se_sub_dev->se_dev_attrib.hw_max_sectors);
-                        return -EINVAL;
-                }
-                if (max_sectors > DA_STATUS_MAX_SECTORS_MAX) {
-                        pr_err("dev[%p]: Passed max_sectors: %u"
-                                " greater than DA_STATUS_MAX_SECTORS_MAX:"
-                                " %u\n", dev, max_sectors,
-                                DA_STATUS_MAX_SECTORS_MAX);
-                        return -EINVAL;
-                }
-        }
-        /*
-         * Align max_sectors down to PAGE_SIZE to follow transport_allocate_data_tasks()
-         */
-        max_sectors = se_dev_align_max_sectors(max_sectors,
-                                dev->se_sub_dev->se_dev_attrib.block_size);
-
-        dev->se_sub_dev->se_dev_attrib.max_sectors = max_sectors;
-        pr_debug("dev[%p]: SE Device max_sectors changed to %u\n",
-                        dev, 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)) {