From: Al Viro <viro@ZenIV.linux.org.uk>
To: Tomeu Vizoso <tomeu@tomeuvizoso.net>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Neil Brown <neilb@suse.com>,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v2 06/11] don't put symlink bodies in pagecache into highmem
Date: Thu, 14 Jan 2016 16:23:34 +0000 [thread overview]
Message-ID: <20160114162333.GX17997@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAAObsKAFcuz_LJTVhm36J7s-mft4c8RgP6KetXcs_r_Mtmm+ig@mail.gmail.com>
On Thu, Jan 14, 2016 at 04:58:48PM +0100, Tomeu Vizoso wrote:
> > Could you add
> > printk(KERN_ERR "i_data = %p, i_mapping = %p, flags: %lx\n",
> > &inode->i_data,
> > inode->i_mapping,
> > (unsigned long)inode->i_data.flags);
> > right before the return from nfs_get_link() and see what it prints?
>
> Here it is:
>
> [ 170.136956] i_data = ed9c1b04, i_mapping = ed9c1b04, flags: 24200c0
> [ 170.144567] i_data = ed9de784, i_mapping = ed9de784, flags: 24200c0
> [ 170.151457] i_data = ed9dec84, i_mapping = ed9dec84, flags: 24200c0
> [ 170.158358] i_data = ed9c3b84, i_mapping = ed9c3b84, flags: 24200c0
> [ 170.165253] i_data = ed9d4204, i_mapping = ed9d4204, flags: 24200c0
> [ 170.172131] i_data = ed9df184, i_mapping = ed9df184, flags: 24200c0
> [ 170.188804] i_data = eddbce84, i_mapping = eddbce84, flags: 24200c0
> [ 170.196158] i_data = ec904984, i_mapping = ec904984, flags: 24200c0
> [ 170.205133] i_data = ec906784, i_mapping = ec906784, flags: 24200c0
Aha. So ->i_data vs. ->i_mapping is irrelevant (as it ought to be here)
and inode_nohighmem() should've acted on the address_space we are hitting
here. What do we have in flags... ___GFP_IO | ___GFP_FS | ___GFP_HARDWALL |
___GFP_DIRECT_RECLAIM | ___GFP_KSWAPD_RECLAIM. IOW, normal GFP_USER, no
__GFP_HIGHMEM in sight.
So either we have a highmem page somehow ending up in i_data before we
set the flags, or __page_cache_alloc() done by read_cache_page() returns
us a highmem page on GFP_USER | __GFP_COLD (or I'm misreading the things
completely)...
Could you slap
printk(KERN_ERR "inode: %p, pages: %ld\n",
inode, inode->i_data.nrpages);
before that read_cache_page() in nfs_get_link() and
printk(KERN_ERR "page_address: %p\n", page_address(page));
right before the return?
next prev parent reply other threads:[~2016-01-14 16:23 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 [this message]
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
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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