----- Mail original ----- > De: "Jim Meyering" <j...@meyering.net> > À: "g esp" <g....@free.fr> > Cc: 12...@debbugs.gnu.org > Envoyé: Jeudi 25 Octobre 2012 18:22:21 > Objet: bug#12730: coreutils-8.20: FAIL: tests/du/bind-mount-dir-cycle.sh >
> > The line in /etc/mtab that let hash.c take a different code path is > > rootfs / rootfs rw 0 0 > I withdraw my conclusion concerning rootfs line. I made something wrong during testing as I can't reproduce that result now. > You wrote this: > > chroot-i486] root:/usr/src/coreutils-8.20$ rm -f /etc/mtab > [chroot-i486] root:/usr/src/coreutils-8.20$ ln -sf /proc/mounts /etc/mtab > [chroot-i486] root:/usr/src/coreutils-8.20$ mount --bind a a/b > [chroot-i486] root:/usr/src/coreutils-8.20$ du a > du: mount point 'a/b' already traversed > 4 a > > [chroot-i486] root:/usr/src/coreutils-8.20$ umount a/b > [chroot-i486] root:/usr/src/coreutils-8.20$ rm -f /etc/mtab > [chroot-i486] root:/usr/src/coreutils-8.20$ grep ' / ' /proc/mounts > >/etc/mtab > [chroot-i486] root:/usr/src/coreutils-8.20$ mount --bind a a/b > [chroot-i486] root:/usr/src/coreutils-8.20$ du a > du: WARNING: Circular directory structure. > This almost certainly means that you have a corrupted file system. > NOTIFY YOUR SYSTEM MANAGER. > The following directory is part of the cycle: > 'a/b' > > 4 a > > Does the latter mount command arrange to add a line to the > one-line (root-only) /etc/mtab ? > Yes I created a/b by hand directly in /usr/src/coreutils-8.20. [chroot-i486] root:/usr/src/coreutils-8.20$ grep '^\/dev.* / ' /proc/mounts >/etc/mtab [chroot-i486] root:/usr/src/coreutils-8.20$ mount --bind a a/b [chroot-i486] root:/usr/src/coreutils-8.20$ cat /etc/mtab /dev/disk/by-uuid/7a235d64-5d04-41ac-a959-70465eb74fc8 / ext3 rw,relatime,errors=remount-ro,barrier=1,data=ordered 0 0 /usr/src/coreutils-8.20/a /usr/src/coreutils-8.20/a/b none rw,bind 0 0 The behavior difference is in hash_lookup in if (bucket->data == NULL) test. I added a few printf to find that. With symlink /etc/mtab, code go further, with regular /etc/mtab, code return NULL there. > To me, it looks like the *lack* of a line for the a/b mount > is the problem. When you remove the symlink the mount command > does not update the regular-file /etc/mtab, so mount-listing > code cannot see that a/b is bind-mounted. > No, this is not a missing line but understanding that line content. To prove that, I started again with a new mtab, - mounted a/b without writting to mtab - copied to mtab a line content with a/b mounted exactly the same as in /proc/mounts case, - hash_lookup answer changed . [chroot-i486] root:/usr/src/coreutils-8.20$ rm -f /etc/mtab [chroot-i486] root:/usr/src/coreutils-8.20$ grep '^\/dev.* / ' /proc/mounts >/etc/mtab [chroot-i486] root:/usr/src/coreutils-8.20$ mount -n --bind a a/b [chroot-i486] root:/usr/src/coreutils-8.20$ echo '/dev/disk/by-uuid/7a235d64-5d04-41ac-a959-70465eb74fc8 /usr/src/coreutils-8.20/a/b ext3 rw,relatime,errors=remount-ro,barrier=1,data=ordered 0 0' >>/etc/mtab [chroot-i486] root:/usr/src/coreutils-8.20$ ./src/du a ./src/du: mount point 'a/b' already traversed 4 a Gilles
