| Message ID | 1320110481-12080-1-git-send-email-xiaoqiangnk@gmail.com |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Tue, Nov 01, 2011 at 09:21:21AM +0800, Yongqiang Yang wrote: > ext4_ext_convert_to_initialized() does not initialize eh before using it > and this is introduced in commit 864d21652. > > Cc:Eric Gouriou <egouriou@google.com> > Cc:"Theodore Ts'o" <tytso@mit.edu> > Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> > eof_block = map->m_lblk + map->m_len; > > depth = ext_depth(inode); > + eh = path[depth].p_hdr; > ex = path[depth].p_ext; > ee_block = le32_to_cpu(ex->ee_block); > ee_len = ext4_ext_get_actual_len(ex); Hmmm, nice catch. Looks like Eric dropped this line when he forward ported this patch to v3.1. Interestingly, I did test this using xfstests, and it didn't complain. Which probably means we don't have a good test coverage that triggers the specific preconditions of this optimization. Oops. I'll fix this up now. Eric, when you have a chance, could you work up an xfstests test that automates the various tests that you ran manually when you developed this patch? Thanks!! - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[Resend of my earlier message with HTML gunk removed and one edit. ] On Tue, Nov 1, 2011 at 15:52, Ted Ts'o <tytso@mit.edu> wrote: > > On Tue, Nov 01, 2011 at 09:21:21AM +0800, Yongqiang Yang wrote: > > ext4_ext_convert_to_initialized() does not initialize eh before using it > > and this is introduced in commit 864d21652. > > > > Cc:Eric Gouriou <egouriou@google.com> > > Cc:"Theodore Ts'o" <tytso@mit.edu> > > Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> > > > eof_block = map->m_lblk + map->m_len; > > > > depth = ext_depth(inode); > > + eh = path[depth].p_hdr; > > ex = path[depth].p_ext; > > ee_block = le32_to_cpu(ex->ee_block); > > ee_len = ext4_ext_get_actual_len(ex); > > Hmmm, nice catch. > > Looks like Eric dropped this line when he forward ported this patch to > v3.1. Indeed I screwed up. Apologies for the trouble. I tested the patch thoroughly on our kernel version, ported it to ~ 2.6.39 and tested. This was a few months ago and could not find the time to complete the work then. When I got a chance to resume the effort, the upstream kernel had changed but I was not supposed to even build it due to security concerns with the kernel.org sources. So I redid the port blind, verified [the file] built but did not test. > Interestingly, I did test this using xfstests, and it didn't > complain. Which probably means we don't have a good test coverage > that triggers the specific preconditions of this optimization. Oops. > I'll fix this up now. > > Eric, when you have a chance, could you work up an xfstests test that > automates the various tests that you ran manually when you developed > this patch? Thanks!! Sure, but the "chance" may not manifest itself soon. Eric > > - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 11/2/11 3:22 AM, Eric Gouriou wrote: > [Resend of my earlier message with HTML gunk removed and one edit. ] > > On Tue, Nov 1, 2011 at 15:52, Ted Ts'o <tytso@mit.edu> wrote: >> >> On Tue, Nov 01, 2011 at 09:21:21AM +0800, Yongqiang Yang wrote: >>> ext4_ext_convert_to_initialized() does not initialize eh before using it >>> and this is introduced in commit 864d21652. >>> >>> Cc:Eric Gouriou <egouriou@google.com> >>> Cc:"Theodore Ts'o" <tytso@mit.edu> >>> Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> >> >>> eof_block = map->m_lblk + map->m_len; >>> >>> depth = ext_depth(inode); >>> + eh = path[depth].p_hdr; >>> ex = path[depth].p_ext; >>> ee_block = le32_to_cpu(ex->ee_block); >>> ee_len = ext4_ext_get_actual_len(ex); >> >> Hmmm, nice catch. >> >> Looks like Eric dropped this line when he forward ported this patch to >> v3.1. > > Indeed I screwed up. Apologies for the trouble. I tested the patch thoroughly > on our kernel version, ported it to ~ 2.6.39 and tested. This was a few months > ago and could not find the time to complete the work then. When I got a chance > to resume the effort, the upstream kernel had changed but I was not supposed > to even build it due to security concerns with the kernel.org sources. > So I redid > the port blind, verified [the file] built but did not test. > >> Interestingly, I did test this using xfstests, and it didn't >> complain. Which probably means we don't have a good test coverage >> that triggers the specific preconditions of this optimization. Oops. >> I'll fix this up now. >> >> Eric, when you have a chance, could you work up an xfstests test that >> automates the various tests that you ran manually when you developed >> this patch? Thanks!! > > Sure, but the "chance" may not manifest itself soon. Which probably means "never" :( This is definitely a "do as I say not as I (always) do" but in general: having testcases used for testing commits, and not putting them into the existing regression suite, is bad development practice. It should be a priority for all of us. I know sometimes it is difficult or impossible (my latest xattr race testcase requires (for now) a bunch of libraries from Ceph, and I haven't found a way around that yet) but "I don't have time" is a poor excuse. How did you do the tests? I'd be glad to give you a hand with the formalized testcase if you need it. Thanks, -Eric (Sandeen) > Eric > >> >> - Ted > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 9dfdf8f..2798945 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2944,6 +2944,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, eof_block = map->m_lblk + map->m_len; depth = ext_depth(inode); + eh = path[depth].p_hdr; ex = path[depth].p_ext; ee_block = le32_to_cpu(ex->ee_block); ee_len = ext4_ext_get_actual_len(ex);
ext4_ext_convert_to_initialized() does not initialize eh before using it and this is introduced in commit 864d21652. Cc:Eric Gouriou <egouriou@google.com> Cc:"Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> --- Hi Eric, Was that patch tested? fs/ext4/extents.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)