** Changed in: util-linux (Ubuntu) Importance: Undecided => Medium ** No longer affects: linux (Ubuntu)
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/712892 Title: mount (silently) ignores options for bind mounts Status in The Util-Linux-ng Set of Utilities: New Status in “util-linux” package in Ubuntu: Triaged Bug description: Binary package hint: util-linux mount ignores any options given for bind mounts and adds an incorrect line to mtab. there is (at least) one exception: the option ro (== read-only). it warns that the bind mount is mounted read-write, if one tries to use that option together with bind. some examples of the current behavior (with comments): ~/bla# mkdir foo ~/bla# mkdir bar ~/bla# touch foo/test ~/bla# mount foo/ bar/ -obind,ro mount: warning: bar/ seems to be mounted read-write. # at least it says so ~/bla# rm bar/test ~/bla# ls bar/test ls: cannot access bar/test: No such file or directory # expected after that warning ~/bla# touch foo/test ~/bla# mount foo/ bar/ -obind,somebogusoption1 ~/bla# mount foo/ bar/ -obind,somebogusoption2 ~/bla# mount foo/ bar/ -obind,somebogusoption3 ~/bla# mount ... /root/bla/foo on /root/bla/bar type none (rw,bind) /root/bla/foo on /root/bla/bar type none (rw,bind,somebogusoption1) /root/bla/foo on /root/bla/bar type none (rw,bind,somebogusoption2) /root/bla/foo on /root/bla/bar type none (rw,bind,somebogusoption3) # mount adds bogus lines to mtab... ~/bla# ls bar/ test # but at least it does mount umount bar mount ... /root/bla/foo on /root/bla/bar type none (rw,bind) /root/bla/foo on /root/bla/bar type none (rw,bind,somebogusoption1) /root/bla/foo on /root/bla/bar type none (rw,bind,somebogusoption2) # and umount only removes one (bogus) line per execution :) the behavior is kinda documented in the manpage (well the bogus lines are clearly a bug (two actually), but i don't care right now). a workaround is to first bind mount and then use the remount option for setting other options e.g.: ~/bla# mount foo/ bar/ -obind ~/bla# mount bar/ -oremount,ro ~/bla# rm bar/test rm: cannot remove `bar/test': Read-only file system the problem is... this does not work with fstab: neither setting up one line with options bind,ro such as /root/bla/foo /root/bla/bar none bind,ro (this gives the same warning as above) nor using two, one with the remount option: /root/bla/foo /root/bla/bar none bind /root/bla/foo /root/bla/bar none remount,ro (this even fails silently to remount read-only!) the warning was introduced by Karel Zak in november 2009. i read that debian had a patch for correcting at least some of the issues above, but i could not find anything. one workaround for certain situations could be to use pam_mount. this war reported/tested on ubuntu 10.10 with kernel 2.6.35-25 and mount 2.17.2-0ubuntu1.10.10.1. To manage notifications about this bug go to: https://bugs.launchpad.net/util-linux-ng/+bug/712892/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
