Re: kmemleak report after 9082e87bfbf8 ("block: remove struct bio_batch")

[Larry Finger]

On 06/07/2016 04:39 AM, Catalin Marinas wrote:

On Mon, Jun 06, 2016 at 12:09:49PM -0500, Shaun Tancheff wrote:

I'm pretty sure it is missing a bio_put() after submit_bio_wait().

Please excuse the hack-y patch but I think you need to do something
like this ...
(Note tabs eaten by gmail).

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 23d7f30..9e29dc3 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -113,6 +113,7 @@ int blkdev_issue_discard(struct block_device
*bdev, sector_t sector,
                 ret = submit_bio_wait(type, bio);
                 if (ret == -EOPNOTSUPP)
                         ret = 0;
+               bio_put(bio);
         }
         blk_finish_plug(&plug);

@@ -165,8 +166,10 @@ int blkdev_issue_write_same(struct block_device
*bdev, sector_t sector,
                 }
         }

-       if (bio)
+       if (bio) {
                 ret = submit_bio_wait(REQ_WRITE | REQ_WRITE_SAME, bio);
+               bio_put(bio);
+       }
         return ret != -EOPNOTSUPP ? ret : 0;
  }
  EXPORT_SYMBOL(blkdev_issue_write_same);
@@ -206,8 +209,11 @@ static int __blkdev_issue_zeroout(struct
block_device *bdev, sector_t sector,
                 }
         }

-       if (bio)
-               return submit_bio_wait(WRITE, bio);
+       if (bio) {
+               ret = submit_bio_wait(WRITE, bio);
+               bio_put(bio);
+               return ret;
+       }
         return 0;
  }

This patch appears to fix the memory leak on my machine.

Tested-by: Catalin Marinas <catalin.mari...@arm.com>

The patch appears to work here as well.

Tested-by: Larry fin...@lwfinger.net

Thanks,

Larry