target: Fix divide by zero bug in fabric_max_sectors for unconfigured devices
commit 7a3cf6ca1ab2a2f7161c6dec5a787fc7a5de864e upstream
This patch fixes a possible divide by zero bug when the fabric_max_sectors
device attribute is written and backend se_device failed to be successfully
configured -> enabled.
Go ahead and use block_size=512 within se_dev_set_fabric_max_sectors()
in the event of a target_configure_device() failure case, as no valid
dev->dev_attrib.block_size value will have been setup yet.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 0943ff0..94fda90 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -1195,6 +1195,8 @@
int se_dev_set_fabric_max_sectors(struct se_device *dev, u32 fabric_max_sectors)
{
+ int block_size = dev->se_sub_dev->se_dev_attrib.block_size;
+
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",
@@ -1232,8 +1234,12 @@
/*
* Align max_sectors down to PAGE_SIZE to follow transport_allocate_data_tasks()
*/
+ if (!block_size) {
+ block_size = 512;
+ pr_warn("Defaulting to 512 for zero block_size\n");
+ }
fabric_max_sectors = se_dev_align_max_sectors(fabric_max_sectors,
- dev->se_sub_dev->se_dev_attrib.block_size);
+ 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",
