linux-kernel - Re: [PATCH 03/18] mm, hugetlb: unify region structure handling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87wqo8ot4m.fsf@linux.vnet.ibm.com>
Date:	Tue, 30 Jul 2013 22:57:37 +0530
From:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
To:	Joonsoo Kim <iamjoonsoo.kim@....com>,
	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Rik van Riel <riel@...hat.com>, Mel Gorman <mgorman@...e.de>,
	Michal Hocko <mhocko@...e.cz>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Hugh Dickins <hughd@...gle.com>,
	Davidlohr Bueso <davidlohr.bueso@...com>,
	David Gibson <david@...son.dropbear.id.au>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, Joonsoo Kim <js1304@...il.com>,
	Wanpeng Li <liwanp@...ux.vnet.ibm.com>,
	Naoya Horiguchi <n-horiguchi@...jp.nec.com>,
	Hillf Danton <dhillf@...il.com>,
	Joonsoo Kim <iamjoonsoo.kim@....com>
Subject: Re: [PATCH 03/18] mm, hugetlb: unify region structure handling

Joonsoo Kim <iamjoonsoo.kim@....com> writes:

> Currently, to track a reserved and allocated region, we use two different
> ways for MAP_SHARED and MAP_PRIVATE. For MAP_SHARED, we use
> address_mapping's private_list and, for MAP_PRIVATE, we use a resv_map.
> Now, we are preparing to change a coarse grained lock which protect
> a region structure to fine grained lock, and this difference hinder it.
> So, before changing it, unify region structure handling.
>
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@....com>
>
> diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
> index a3f868a..a1ae3ada 100644
> --- a/fs/hugetlbfs/inode.c
> +++ b/fs/hugetlbfs/inode.c
> @@ -366,7 +366,12 @@ static void truncate_hugepages(struct inode *inode, loff_t lstart)
>
>  static void hugetlbfs_evict_inode(struct inode *inode)
>  {
> +	struct resv_map *resv_map;
> +
>  	truncate_hugepages(inode, 0);
> +	resv_map = (struct resv_map *)inode->i_mapping->private_data;
> +	if (resv_map)

can resv_map == NULL ?


> +		kref_put(&resv_map->refs, resv_map_release);

Also the kref_put is confusing. For shared mapping we don't have ref
count incremented right ? So may be you can directly call
resv_map_release or add a comment around explaining this more ?


>  	clear_inode(inode);
>  }
>
> @@ -468,6 +473,11 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
>  					umode_t mode, dev_t dev)
>  {
>  	struct inode *inode;
> +	struct resv_map *resv_map;
> +
> +	resv_map = resv_map_alloc();
> +	if (!resv_map)
> +		return NULL;

-aneesh

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