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| author | Willy Tarreau <w@1wt.eu> | 2016-08-27 11:31:35 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-11 09:59:58 +0200 |
| commit | 7cac57a69919afdf3bdda5242afdd535b2d9a2b0 (patch) | |
| tree | 7e1935d9d312cc89985df52a80b10d7880421988 | |
| parent | 78a4260f1fad5cfc6ad7cf6e01a93a2fed0d0e3e (diff) | |
| download | linux-stable-7cac57a69919afdf3bdda5242afdd535b2d9a2b0.tar.gz linux-stable-7cac57a69919afdf3bdda5242afdd535b2d9a2b0.tar.bz2 linux-stable-7cac57a69919afdf3bdda5242afdd535b2d9a2b0.zip | |
fix d_walk()/non-delayed __d_free() race
I checked Jari's explanation below and found that v3.14.77 and v3.12.62
are missing the same fix as 3.10. In fact Al's original commit 3d56c25
("fix d_walk()/non-delayed __d_free() race") used to mention to check
this __d_materialise_dentry() function in the Cc: stable line, but this
got lost during the backports.
Normally all of our 3 kernels need to apply the following patch that
Ben correctly put in 3.16 and 3.2. I'm fixing the backport in 3.10.103
right now.
On Mon, Aug 22, 2016 at 04:56:57PM +0300, Jari Ruusu wrote:
> This patch for 3.10 branch appears to be missing one important
>
> + dentry->d_flags |= DCACHE_RCUACCESS;
>
> in fs/dcache.c __d_materialise_dentry() function. When Ben Hutchings
> backported Al Viro's original fix to stable branches that he maintains,
> he added that one additional line to both 3.2 and 3.16 branches. Please
> consider including that additional one line fix for 3.10 stable branch
> also.
>
>
> Ben Hutchings said this on his 3.2.82-rc1 patch:
> [bwh: Backported to 3.2:
> - Adjust context
> - Also set the flag in __d_materialise_dentry())]
>
> http://marc.info/?l=linux-kernel&m=147117565612275&w=2
>
>
> Ben Hutchings said this on his 3.16.37-rc1 patch:
> [bwh: Backported to 3.16:
> - Adjust context
> - Also set the flag in __d_materialise_dentry())]
>
> http://marc.info/?l=linux-kernel&m=147117433412006&w=2
>
>
> Also mentioned by Sasha Levin on 3.18 and 4.1 commits:
> Cc: stable@vger.kernel.org # v3.2+ (and watch out for __d_materialise_dentry())
>
> http://marc.info/?l=linux-stable-commits&m=146648034410827&w=2
> http://marc.info/?l=linux-stable-commits&m=146647471009771&w=2
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/dcache.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 47c06888dc05..4d170433c647 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2652,6 +2652,7 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon) switch_names(dentry, anon); swap(dentry->d_name.hash, anon->d_name.hash); + dentry->d_flags |= DCACHE_RCUACCESS; dentry->d_parent = dentry; list_del_init(&dentry->d_child); anon->d_parent = dparent; |