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authorQuinn Tran <quinn.tran@qlogic.com>2014-03-28 19:05:27 -0400
committerNicholas Bellinger <nab@linux-iscsi.org>2014-04-07 01:48:53 -0700
commit9d2e59f2a778328a41771fe9a0098dadbc4314ba (patch)
tree3a921494b5de360dda42f639bab92cdc03d427e1 /drivers/target
parentd444edc679e7713412f243b792b1f964e5cff1e1 (diff)
target/rd: T10-Dif: RAM disk is allocating more space than required.
Ram disk is allocating 8x more space than required for diff data. For large RAM disk test, there is small potential for memory starvation. (Use block_size when calculating total_sg_needed - sagi + nab) Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com> Signed-off-by: Quinn Tran <quinn.tran@qlogic.com> Cc: <stable@vger.kernel.org> #3.14+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/target_core_rd.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index 66a5aba5a0d9..b920db3388cd 100644
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -242,7 +242,7 @@ static void rd_release_prot_space(struct rd_dev *rd_dev)
rd_dev->sg_prot_count = 0;
}
-static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length)
+static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
{
struct rd_dev_sg_table *sg_table;
u32 total_sg_needed, sg_tables;
@@ -252,8 +252,13 @@ static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length)
if (rd_dev->rd_flags & RDF_NULLIO)
return 0;
-
- total_sg_needed = rd_dev->rd_page_count / prot_length;
+ /*
+ * prot_length=8byte dif data
+ * tot sg needed = rd_page_count * (PGSZ/block_size) *
+ * (prot_length/block_size) + pad
+ * PGSZ canceled each other.
+ */
+ total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
sg_tables = (total_sg_needed / max_sg_per_table) + 1;
@@ -606,7 +611,8 @@ static int rd_init_prot(struct se_device *dev)
if (!dev->dev_attrib.pi_prot_type)
return 0;
- return rd_build_prot_space(rd_dev, dev->prot_length);
+ return rd_build_prot_space(rd_dev, dev->prot_length,
+ dev->dev_attrib.block_size);
}
static void rd_free_prot(struct se_device *dev)