Re: [PATCH 1/6] UBI: Fastmap: Fix memory leaks while closing the WL sub-system

From: Tanya Brokhman
Date: Sun Dec 07 2014 - 08:27:03 EST

On 12/7/2014 1:34 PM, Richard Weinberger wrote:
Am 07.12.2014 um 12:32 schrieb Tanya Brokhman:
On 12/7/2014 11:54 AM, Richard Weinberger wrote:
Am 07.12.2014 um 09:13 schrieb Tanya Brokhman:
On 11/30/2014 1:35 PM, Richard Weinberger wrote:
Add a ubi_fastmap_close() to free all resources used by fastmap
at WL shutdown.

Signed-off-by: Richard Weinberger <richard@xxxxxx>
drivers/mtd/ubi/wl.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index c2822f7..47b215f 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -2064,6 +2064,23 @@ static void protection_queue_destroy(struct ubi_device *ubi)

+static void ubi_fastmap_close(struct ubi_device *ubi)
+ int i;
+ flush_work(&ubi->fm_work);
+ return_unused_pool_pebs(ubi, &ubi->fm_pool);
+ return_unused_pool_pebs(ubi, &ubi->fm_wl_pool);
+ if (ubi->fm) {
+ for (i = 0; i < ubi->fm->used_blocks; i++)
+ kfree(ubi->fm->e[i]);
+ }
+ kfree(ubi->fm);


No this is not a typo, I kfree() here ubi->fm by design.
What am I missing? :)

I think you missed freeing ubi->fm_buf, before (not instead) you free ubi->fm :)

No. fm_buf is vfree()d upon detach time.

you're right, found it at ubi_detach_mtd_dev() several lines after calling ubi_wl_close(). But if you're creating a fastmap-close dedicated function, fm_buf should be freed in it as it is fastmap related.


Tanya Brokhman
Qualcomm Israel, on behalf of Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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