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authorNicholas Bellinger <nab@linux-iscsi.org>2013-02-19 03:15:14 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-02-27 09:21:24 -0800
commitca2656dccef64c437d6717468bffd3762b11816e (patch)
tree646b4d2f724f032e675e6122925f5b32e02111d8
parent732b2a1a4bb58677ba9c7be3fac0960ceccc9b8f (diff)
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>
-rw-r--r--drivers/target/target_core_device.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 0943ff06d82e..94fda907b8e6 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -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",