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Commit 7a3cf6ca authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target: Fix divide by zero bug in fabric_max_sectors for unconfigured devices 



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.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent faa06ab9

drivers/target/target_core_device.c

+7 −1
Original line number Diff line number Diff line
@@ -941,6 +941,8 @@ int se_dev_set_queue_depth(struct se_device *dev, u32 queue_depth) 


int se_dev_set_fabric_max_sectors(struct se_device *dev, u32 fabric_max_sectors)

{

	int block_size = dev->dev_attrib.block_size;



	if (dev->export_count) {

		pr_err("dev[%p]: Unable to change SE Device"

			" fabric_max_sectors while export_count is %d\n",
@@ -978,8 +980,12 @@ int se_dev_set_fabric_max_sectors(struct se_device *dev, u32 fabric_max_sectors) 
	/*

	 * 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->dev_attrib.block_size);

						      block_size);



	dev->dev_attrib.fabric_max_sectors = fabric_max_sectors;

	pr_debug("dev[%p]: SE Device max_sectors changed to %u\n",