From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tomeu Vizoso <tomeu@tomeuvizoso.net>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Neil Brown <neilb@suse.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH v2 06/11] don't put symlink bodies in pagecache into highmem
Date: Fri, 15 Jan 2016 00:05:09 +0000 [thread overview]
Message-ID: <20160115000509.GD17997@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CA+55aFwtrHfckEdZy6_5jbjc7nuMTTM5Pz=A6sYt_h6+0MXcug@mail.gmail.com>
On Thu, Jan 14, 2016 at 03:58:22PM -0800, Linus Torvalds wrote:
> On Thu, Jan 14, 2016 at 2:25 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > For one thing, we'll lose RCU ->get_link() for those.
>
> Why couldn't we just do that in the RCU walker? kmap should be fine..
In map_new_virtual():
__set_current_state(TASK_UNINTERRUPTIBLE);
add_wait_queue(pkmap_map_wait, &wait);
unlock_kmap();
schedule();
remove_wait_queue(pkmap_map_wait, &wait);
lock_kmap();
IOW, not in RCU mode ;-/
> That said, as long as you think it's ok now, I guess I don't care.
> Having some sanity testing in __add_to_page_cache_locked might be a
> good safety net.
That's better as a separate commit, IMO. The thing I'm not sure about is
whether we want a BUG() in there - VM_WARN_ON(), perhaps? OTOH, we do
have VM_BUG_ON_PAGE() in the same place already...
next prev parent reply other threads:[~2016-01-15 0:05 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-17 22:57 [PATCHSET] ->follow_link() without dropping from RCU mode Al Viro
2015-11-17 23:00 ` [PATCH 01/10] switch befs long symlinks to page_symlink_operations Al Viro
2015-11-17 23:00 ` [PATCH 02/10] logfs: don't duplicate page_symlink_inode_operations Al Viro
2015-11-17 23:00 ` [PATCH 03/10] udf: " Al Viro
2015-11-17 23:00 ` [PATCH 04/10] ufs: get rid of ->setattr() for symlinks Al Viro
2015-11-17 23:00 ` [PATCH 05/10] namei: page_getlink() and page_follow_link_light() are the same thing Al Viro
2015-11-17 23:00 ` [PATCH 06/10] [vfs] don't put symlink bodies in pagecache into highmem Al Viro
2015-11-19 23:02 ` Dave Chinner
2015-11-17 23:00 ` [PATCH 07/10] [vfs] replace ->follow_link() with new method that could stay in RCU mode Al Viro
2015-11-17 23:00 ` [PATCH 08/10] teach page_get_link() to work " Al Viro
2015-11-17 23:00 ` [PATCH 09/10] teach shmem_get_link() " Al Viro
2015-11-17 23:00 ` [PATCH 10/10] teach proc_self_get_link()/proc_thread_self_get_link() " Al Viro
2015-12-09 5:32 ` [PATCHSET v2] ->follow_link() without dropping from " Al Viro
2015-12-09 5:34 ` [PATCH v2 01/11] switch befs long symlinks to page_symlink_operations Al Viro
2015-12-09 5:34 ` [PATCH v2 02/11] logfs: don't duplicate page_symlink_inode_operations Al Viro
2015-12-09 5:34 ` [PATCH v2 03/11] udf: " Al Viro
2015-12-09 5:34 ` [PATCH v2 04/11] ufs: get rid of ->setattr() for symlinks Al Viro
2015-12-09 5:34 ` [PATCH v2 05/11] namei: page_getlink() and page_follow_link_light() are the same thing Al Viro
2015-12-09 5:34 ` [PATCH v2 06/11] don't put symlink bodies in pagecache into highmem Al Viro
2016-01-14 13:22 ` Tomeu Vizoso
2016-01-14 15:25 ` Al Viro
2016-01-14 15:58 ` Tomeu Vizoso
2016-01-14 16:23 ` Al Viro
2016-01-14 16:57 ` Tomeu Vizoso
2016-01-14 17:13 ` Al Viro
2016-01-14 19:15 ` Tomeu Vizoso
2016-01-14 21:02 ` Al Viro
2016-01-14 21:40 ` Linus Torvalds
2016-01-14 22:25 ` Al Viro
2016-01-14 23:33 ` Al Viro
2016-01-14 23:58 ` Linus Torvalds
2016-01-15 0:05 ` Al Viro [this message]
2015-12-09 5:34 ` [PATCH v2 07/11] replace ->follow_link() with new method that could stay in RCU mode Al Viro
2015-12-09 5:34 ` [PATCH v2 08/11] teach page_get_link() to work " Al Viro
2015-12-09 5:34 ` [PATCH v2 09/11] teach shmem_get_link() " Al Viro
2015-12-09 5:34 ` [PATCH v2 10/11] teach proc_self_get_link()/proc_thread_self_get_link() " Al Viro
2015-12-09 5:34 ` [PATCH v2 11/11] teach nfs_get_link() " Al Viro
2015-12-09 17:24 ` [PATCHSET v2] ->follow_link() without dropping from " Linus Torvalds
2015-12-09 18:23 ` Al Viro
2015-12-10 0:10 ` Al Viro
2015-12-10 2:40 ` Al Viro
2015-12-11 1:54 ` Al Viro
2015-12-11 7:49 ` Rasmus Villemoes
2015-12-11 23:16 ` Al Viro
2015-12-12 2:00 ` Al Viro
2015-12-13 18:43 ` Rasmus Villemoes
2015-12-13 3:47 ` Al Viro
2015-12-09 21:57 ` NeilBrown
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