From: Amir Goldstein <amir73il@gmail.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>,
Eric Sandeen <sandeen@redhat.com>,
Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
linux-cifs@vger.kernel.org,
overlayfs <linux-unionfs@vger.kernel.org>,
linux-xfs <linux-xfs@vger.kernel.org>,
Linux MM <linux-mm@kvack.org>,
Linux Btrfs <linux-btrfs@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
ocfs2-devel@oss.oracle.com
Subject: Re: [PATCH v3 00/25] fs: fixes for serious clone/dedupe problems
Date: Thu, 11 Oct 2018 11:33:57 +0300 [thread overview]
Message-ID: <CAOQ4uxgOvOOnKL5TsC9jpjBsepAgtQ56Hhjh7WDeXM7m0=dz7g@mail.gmail.com> (raw)
In-Reply-To: <153923113649.5546.9840926895953408273.stgit@magnolia>
On Thu, Oct 11, 2018 at 7:12 AM Darrick J. Wong <darrick.wong@oracle.com> wrote:
>
> Hi all,
>
> Dave, Eric, and I have been chasing a stale data exposure bug in the XFS
> reflink implementation, and tracked it down to reflink forgetting to do
> some of the file-extending activities that must happen for regular
> writes.
>
> We then started auditing the clone, dedupe, and copyfile code and
> realized that from a file contents perspective, clonerange isn't any
> different from a regular file write. Unfortunately, we also noticed
> that *unlike* a regular write, clonerange skips a ton of overflow
> checks, such as validating the ranges against s_maxbytes, MAX_NON_LFS,
> and RLIMIT_FSIZE. We also observed that cloning into a file did not
> strip security privileges (suid, capabilities) like a regular write
> would. I also noticed that xfs and ocfs2 need to dump the page cache
> before remapping blocks, not after.
>
> In fixing the range checking problems I also realized that both dedupe
> and copyfile tell userspace how much of the requested operation was
> acted upon. Since the range validation can shorten a clone request (or
> we can ENOSPC midway through), we might as well plumb the short
> operation reporting back through the VFS indirection code to userspace.
>
> So, here's the whole giant pile of patches[1] that fix all the problems.
> This branch is against 4.19-rc7 with Dave Chinner's XFS for-next branch.
> The patch "generic: test reflink side effects" recently sent to fstests
> exercises the fixes in this series. Tests are in [2].
>
> --D
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=djwong-devel
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfstests-dev.git/log/?h=djwong-devel
I tested your branch with overlayfs over xfs.
I did not observe any failures with -g clone except for test generic/937
which also failed on xfs in my test.
I though that you forgot to mention I needed to grab xfsprogs from djwong-devel
for commit e84a9e93 ("xfs_io: dedupe command should only complain
if we don't dedupe anything"), but even with this change the test still fails:
generic/937 - output mismatch (see
/old/home/amir/src/fstests/xfstests-dev/results//generic/937.out.bad)
--- tests/generic/937.out 2018-10-11 08:23:00.630938364 +0300
+++ /old/home/amir/src/fstests/xfstests-dev/results//generic/937.out.bad
2018-10-11 10:54:40.448134832 +0300
@@ -4,8 +4,7 @@
39578c21e2cb9f6049b1cf7fc7be12a6 TEST_DIR/test-937/file2
Files 1-2 do not match (intentional)
(partial) dedupe the middle blocks together
-deduped XXXX/XXXX bytes at offset XXXX
-XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+XFS_IOC_FILE_EXTENT_SAME: Extents did not match.
Compare sections
One thing that *is* different with overlayfs test is that filefrag crashes
on this same test:
QA output created by 937
Create the original files
35ac8d7917305c385c30f3d82c30a8f6 TEST_DIR/test-937/file1
39578c21e2cb9f6049b1cf7fc7be12a6 TEST_DIR/test-937/file2
Files 1-2 do not match (intentional)
(partial) dedupe the middle blocks together
XFS_IOC_FILE_EXTENT_SAME: Extents did not match.
./tests/generic/937: line 59: 19242 Floating point exception(core
dumped) ${FILEFRAG_PROG} -v $testdir/file1 >> $seqres.full
./tests/generic/937: line 60: 19244 Floating point exception(core
dumped) ${FILEFRAG_PROG} -v $testdir/file2 >> $seqres.full
It looks like an overlayfs v4.19-rc1 regression - FIGETBSZ returns zero.
I never noticed this regression before, because none of the generic tests
are using filefrag.
Thanks,
Amir.
next prev parent reply other threads:[~2018-10-11 8:33 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-11 4:12 [PATCH v3 00/25] fs: fixes for serious clone/dedupe problems Darrick J. Wong
2018-10-11 4:12 ` [PATCH 01/25] xfs: add a per-xfs trace_printk macro Darrick J. Wong
2018-10-11 13:39 ` Christoph Hellwig
2018-10-11 23:34 ` Darrick J. Wong
2018-10-11 4:12 ` [PATCH 02/25] vfs: vfs_clone_file_prep_inodes should return EINVAL for a clone from beyond EOF Darrick J. Wong
2018-10-11 13:40 ` Christoph Hellwig
2018-10-11 4:12 ` [PATCH 03/25] vfs: check file ranges before cloning files Darrick J. Wong
2018-10-11 13:42 ` Christoph Hellwig
2018-10-11 14:13 ` Amir Goldstein
2018-10-11 4:12 ` [PATCH 04/25] vfs: strengthen checking of file range inputs to generic_remap_checks Darrick J. Wong
2018-10-11 13:43 ` Christoph Hellwig
2018-10-11 4:12 ` [PATCH 05/25] vfs: avoid problematic remapping requests into partial EOF block Darrick J. Wong
2018-10-12 0:16 ` Dave Chinner
2018-10-12 16:07 ` Darrick J. Wong
2018-10-12 20:22 ` Filipe Manana
2018-10-15 0:31 ` Dave Chinner
2018-11-02 12:04 ` Filipe Manana
2018-11-02 17:42 ` Darrick J. Wong
2018-11-02 18:18 ` Filipe Manana
2018-11-02 19:05 ` Filipe Manana
2018-10-11 4:13 ` [PATCH 06/25] vfs: skip zero-length dedupe requests Darrick J. Wong
2018-10-11 4:13 ` [PATCH 07/25] vfs: combine the clone and dedupe into a single remap_file_range Darrick J. Wong
2018-10-11 4:13 ` [PATCH 08/25] vfs: rename vfs_clone_file_prep to be more descriptive Darrick J. Wong
2018-10-11 4:13 ` [PATCH 09/25] vfs: rename clone_verify_area to remap_verify_area Darrick J. Wong
2018-10-11 4:13 ` [PATCH 10/25] vfs: create generic_remap_file_range_touch to update inode metadata Darrick J. Wong
2018-10-11 4:13 ` [PATCH 11/25] vfs: pass remap flags to generic_remap_file_range_prep Darrick J. Wong
2018-10-11 4:13 ` [PATCH 12/25] vfs: pass remap flags to generic_remap_checks Darrick J. Wong
2018-10-11 4:13 ` [PATCH 13/25] vfs: make remap_file_range functions take and return bytes completed Darrick J. Wong
2018-10-11 4:14 ` [PATCH 14/25] vfs: plumb RFR_* remap flags through the vfs clone functions Darrick J. Wong
2018-10-11 4:14 ` [PATCH 15/25] vfs: plumb RFR_* remap flags through the vfs dedupe functions Darrick J. Wong
2018-10-11 4:14 ` [PATCH 16/25] vfs: make remapping to source file eof more explicit Darrick J. Wong
2018-10-11 4:14 ` [PATCH 17/25] vfs: enable remap callers that can handle short operations Darrick J. Wong
2018-10-11 5:15 ` Amir Goldstein
2018-10-11 16:04 ` Darrick J. Wong
2018-10-11 16:05 ` [PATCH v2 " Darrick J. Wong
2018-10-11 4:14 ` [PATCH 18/25] vfs: hide file range comparison function Darrick J. Wong
2018-10-11 4:14 ` [PATCH 19/25] vfs: implement opportunistic short dedupe Darrick J. Wong
2018-10-11 4:14 ` [PATCH 20/25] ocfs2: truncate page cache for clone destination file before remapping Darrick J. Wong
2018-10-11 4:14 ` [PATCH 21/25] ocfs2: fix pagecache truncation prior to reflink Darrick J. Wong
2018-10-11 4:15 ` [PATCH 22/25] ocfs2: support partial clone range and dedupe range Darrick J. Wong
2018-10-11 4:15 ` [PATCH 23/25] xfs: fix pagecache truncation prior to reflink Darrick J. Wong
2018-10-12 1:15 ` Dave Chinner
2018-10-11 4:15 ` [PATCH 24/25] xfs: support returning partial reflink results Darrick J. Wong
2018-10-12 1:22 ` Dave Chinner
2018-10-12 16:06 ` Darrick J. Wong
2018-10-11 4:15 ` [PATCH 25/25] xfs: remove redundant remap partial EOF block checks Darrick J. Wong
2018-10-12 1:22 ` Dave Chinner
2018-10-11 8:33 ` Amir Goldstein [this message]
2018-10-11 15:55 ` [PATCH v3 00/25] fs: fixes for serious clone/dedupe problems Darrick J. Wong
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