On Tue, Jul 20, 2021 at 10:18 AM Amir Goldstein <amir73il@xxxxxxxxx> wrote:
>
> On Tue, Jul 20, 2021 at 7:22 AM Miklos Szeredi <miklos@xxxxxxxxxx> wrote:
> >
> > On Tue, 20 Jul 2021 at 06:19, Miklos Szeredi <miklos@xxxxxxxxxx> wrote:
> > >
> > > On Mon, 19 Jul 2021 at 18:43, Amir Goldstein <amir73il@xxxxxxxxx> wrote:
> > > >
> > > > On Mon, Jul 19, 2021 at 6:24 PM Miklos Szeredi <miklos@xxxxxxxxxx> wrote:
> > > > >
> > > > > On Fri, 4 Jun 2021 at 12:43, Amir Goldstein <amir73il@xxxxxxxxx> wrote:
> > > > > >
> > > > > > On Mon, Apr 26, 2021 at 6:20 PM Amir Goldstein <amir73il@xxxxxxxxx> wrote:
> > > > > > >
> > > > > > > On the first getdents call, ovl_iterate() populates the readdir cache
> > > > > > > with a list of entries, but for upper entries with origin lower inode,
> > > > > > > p->ino remains zero.
> > > > > > >
> > > > > > > Following getdents calls traverse the readdir cache list and call
> > > > > > > ovl_cache_update_ino() for entries with zero p->ino to lookup the entry
> > > > > > > in the overlay and return d_ino that is consistent with st_ino.
> > > > > > >
> > > > > > > If the upper file was unlinked between the first getdents call and the
> > > > > > > getdents call that lists the file entry, ovl_cache_update_ino() will not
> > > > > > > find the entry and fall back to setting d_ino to the upper real st_ino,
> > > > > > > which is inconsistent with how this object was presented to users.
> > > > > > >
> > > > > > > Instead of listing a stale entry with inconsistent d_ino, simply skip
> > > > > > > the stale entry, which is better for users.
> > > > > > >
> > > > > >
> > > > > > Miklos,
> > > > > >
> > > > > > I forgot to follow up on this patch.
> > > > > > Upstream xfstest overlay/077 is failing without this patch.
> > > > >
> > > > > Can't reproduce (on ext4/xfs and "-oxino=on").
> > > > >
> > > > > Is there some trick?
> > > >
> > > > Not sure. overlay/077 fails for me on v5.14.0-rc2 on ext4/xfs.
> > > >
> > > > QA output created by 077
> > > > +entry m100 has inconsistent d_ino (234 != 232)
> > > > +entry f100 has inconsistent d_ino (335 != 16777542)
> > > > Silence is golden
> > > >
> > > > Maybe you need to build src/t_dir_offset2?
> > >
> > > root@kvm:/opt/xfstests-dev# git log -1 --pretty=%h
> > > 10f6b231
> > > root@kvm:/opt/xfstests-dev# cat local.config
> > > export TEST_DEV=/dev/vdb1
> > > export TEST_DIR=/test
> > > export SCRATCH_DEV=/dev/vdb2
> > > export SCRATCH_MNT=/scratch
> > > export FSTYP=ext4
> > > export OVERLAY_MOUNT_OPTIONS="-o xino=on"
> > > root@kvm:/opt/xfstests-dev# make src/t_dir_offset2
> > > make: 'src/t_dir_offset2' is up to date.
> > > root@kvm:/opt/xfstests-dev# ./check -overlay overlay/077
> > > FSTYP -- overlay
> > > PLATFORM -- Linux/x86_64 kvm 5.14.0-rc2 #276 SMP Tue Jul 20
> > > 05:54:44 CEST 2021
> > > MKFS_OPTIONS -- /scratch
> > > MOUNT_OPTIONS -- -o xino=on /scratch /scratch/ovl-mnt
> > >
> > > overlay/077 1s ... 1s
> > > Ran: overlay/077
> > > Passed all 1 tests
> > >
> > > root@kvm:/opt/xfstests-dev# cat results/overlay/077.full
> > >
> > > Create file in pure upper dir:
> > > getdents at offset 0 returned 192 bytes
> > > created entry p0
> > > entry p0 found as expected
> > >
> > > Remove file in pure upper dir:
> > > getdents at offset 0 returned 192 bytes
> > > unlinked entry p100
> > > entry p100 not found as expected
> > >
> > > Create file in impure upper dir:
> > > getdents at offset 0 returned 192 bytes
> > > created entry o0
> > > entry o0 found as expected
> > >
> > > Remove file in impure upper dir:
> > > getdents at offset 0 returned 192 bytes
> > > unlinked entry o100
> > > entry o100 not found as expected
> > >
> > > Create file in merge dir:
> > > getdents at offset 0 returned 192 bytes
> > > created entry m0
> > > entry m0 found as expected
> > >
> > > Remove file in merge dir:
> > > getdents at offset 0 returned 192 bytes
> > > unlinked entry m100
> > > entry m100 not found as expected
> > >
> > > Create file in former merge dir:
> > > getdents at offset 0 returned 192 bytes
> > > created entry f0
> > > entry f0 found as expected
> > >
> > > Remove file in former merge dir:
> > > getdents at offset 0 returned 192 bytes
> > > unlinked entry f100
> > > entry f100 not found as expected
> > >
> > > Ideas for further debugging why this test isn't failing for v4.12-rc2?
> >
>
> It's not you, it's me ;-)
>
> The failure was lost during cleanup of t_dir_offset2 patches
> for submission and it is I who was running an older version
> of t_dir_offset2. Let me figure this out and get back to you
> with a working test.
>
How about you try again with a version of the test that actually has
the check and the error print that I reported.... ;-)
Thanks,
Amir.
From 250615da6f01e99c055b7fc3bd9a2c1deac644e0 Mon Sep 17 00:00:00 2001
From: Amir Goldstein <amir73il@xxxxxxxxx>
Date: Tue, 20 Jul 2021 17:45:43 +0300
Subject: [PATCH] src/t_dir_offset2: Check for inconsistent d_ino/st_ino
After unlink of a directory entry, that entry may still apear in getdents
results of an already open directory fd, but it should return a d_ino
value that is consistent with the already observed st_ino of that entry.
This is a regression test for kernel commit ....
("ovl: skip stale entries in merge dir cache iteration")
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
src/t_dir_offset2.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/src/t_dir_offset2.c b/src/t_dir_offset2.c
index 75b41c1a..026bc8f3 100644
--- a/src/t_dir_offset2.c
+++ b/src/t_dir_offset2.c
@@ -44,6 +44,7 @@ int main(int argc, char *argv[])
char buf[BUF_SIZE];
int nread, bufsize = BUF_SIZE;
struct linux_dirent64 *d;
+ struct stat st = {};
int bpos, total, i;
off_t lret;
int retval = EXIT_SUCCESS;
@@ -81,9 +82,9 @@ int main(int argc, char *argv[])
}
if (filename) {
- exists = !faccessat(fd, filename, F_OK, AT_SYMLINK_NOFOLLOW);
+ exists = !fstatat(fd, filename, &st, AT_SYMLINK_NOFOLLOW);
if (!exists && errno != ENOENT) {
- perror("faccessat");
+ perror("fstatat");
exit(EXIT_FAILURE);
}
}
@@ -139,9 +140,6 @@ int main(int argc, char *argv[])
continue;
}
- if (nread == 0)
- break;
-
for (bpos = 0; bpos < nread; total++) {
d = (struct linux_dirent64 *) (buf + bpos);
@@ -165,8 +163,16 @@ int main(int argc, char *argv[])
printf("entry #%d: %s (d_ino=%lld, d_off=%lld)\n",
i, d->d_name, (long long int)d->d_ino,
(long long int)d->d_off);
- if (!strcmp(filename, d->d_name))
+ if (!strcmp(filename, d->d_name)) {
found = 1;
+ if (st.st_ino && d->d_ino != st.st_ino) {
+ fprintf(stderr, "entry %s has inconsistent d_ino (%lld != %lld)\n",
+ filename,
+ (long long int)d->d_ino,
+ (long long int)st.st_ino);
+ }
+ }
+
}
bpos += d->d_reclen;
}
--
2.32.0
