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

commit 7a3cf6ca1a 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>
This commit is contained in:
Nicholas Bellinger 2013-02-19 03:15:14 +00:00 committed by Greg Kroah-Hartman
parent 732b2a1a4b
commit ca2656dcce

View File

@ -1195,6 +1195,8 @@ 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->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 @@ 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->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",