| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.14 092/158] target/rd: T10-Dif: RAM disk is allocating more space than required. | Date | Sun, 4 May 2014 11:40:01 -0400 |
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3.14-stable review patch. If anyone has any objections, please let me know.
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From: Quinn Tran <quinn.tran@qlogic.com>
commit 9d2e59f2a778328a41771fe9a0098dadbc4314ba upstream.
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> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/target/target_core_rd.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
--- 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->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 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 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)
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