linux-kernel - Re: [PATCH] mm: Use GFP_KERNEL allocation for the page cache in page_cache

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: <20150318145528.GK17241@dhcp22.suse.cz>
Date:	Wed, 18 Mar 2015 15:55:28 +0100
From:	Michal Hocko <mhocko@...e.cz>
To:	Rik van Riel <riel@...hat.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Al Viro <viro@...iv.linux.org.uk>,
	Johannes Weiner <hannes@...xchg.org>,
	Mel Gorman <mgorman@...e.de>, Neil Brown <neilb@...e.de>,
	Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>,
	Sage Weil <sage@...tank.com>, Mark Fasheh <mfasheh@...e.com>,
	linux-mm@...ck.org, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mm: Use GFP_KERNEL allocation for the page cache in
 page_cache_read

On Wed 18-03-15 10:44:11, Rik van Riel wrote:
> On 03/18/2015 10:09 AM, Michal Hocko wrote:
> > page_cache_read has been historically using page_cache_alloc_cold to
> > allocate a new page. This means that mapping_gfp_mask is used as the
> > base for the gfp_mask. Many filesystems are setting this mask to
> > GFP_NOFS to prevent from fs recursion issues. page_cache_read is,
> > however, not called from the fs layer 
> 
> Is that true for filesystems that have directories in
> the page cache?

I haven't found any explicit callers of filemap_fault except for ocfs2
and ceph and those seem OK to me. Which filesystems you have in mind?

Btw. how would that work as we already have GFP_KERNEL allocation few
lines below?

-- 
Michal Hocko
SUSE Labs
--
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/