[PATCH] blk-mg-tag: Make tag's codeflow more reasonably during initializing

From: Minfei Huang
Date: Fri Nov 27 2015 - 03:36:01 EST


From: Minfei Huang <mnfhuang@xxxxxxxxx>

It might be more reasonable to cleanup all of the allocations in same
function, if there is a fatal. Thus we can make function more
independency to export it.

For this patch, variant tag will be allocated in blk_mq_init_tags, and
it will be freed in same function, if there is an error during
initializing the tag.

What the blk_mq_init_bitmap_tags does is to allocate bitmap.

Signed-off-by: Minfei Huang <mnfhuang@xxxxxxxxx>
---
block/blk-mq-tag.c | 30 ++++++++++++++++++------------
1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index a07ca34..7a1d9a8 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -596,23 +596,24 @@ static void bt_free(struct blk_mq_bitmap_tags *bt)
kfree(bt->bs);
}

-static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
- int node, int alloc_policy)
+static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
+ int node, int alloc_policy)
{
+ int ret = 0;
unsigned int depth = tags->nr_tags - tags->nr_reserved_tags;

tags->alloc_policy = alloc_policy;

- if (bt_alloc(&tags->bitmap_tags, depth, node, false))
- goto enomem;
- if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, node, true))
- goto enomem;
+ ret = bt_alloc(&tags->bitmap_tags, depth, node, false);
+ if (ret)
+ goto out;

- return tags;
-enomem:
- bt_free(&tags->bitmap_tags);
- kfree(tags);
- return NULL;
+ ret = bt_alloc(&tags->breserved_tags,
+ tags->nr_reserved_tags, node, true);
+ if (ret)
+ bt_free(&tags->bitmap_tags);
+out:
+ return ret;
}

struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
@@ -638,7 +639,12 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
tags->nr_tags = total_tags;
tags->nr_reserved_tags = reserved_tags;

- return blk_mq_init_bitmap_tags(tags, node, alloc_policy);
+ if (blk_mq_init_bitmap_tags(tags, node, alloc_policy)) {
+ kfree(tags);
+ return NULL;
+ }
+
+ return tags;
}

void blk_mq_free_tags(struct blk_mq_tags *tags)
--
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/