kernel.git/fs/overlayfs/super.c, branch linux-4.8.y

ovl: fix d_real() for stacked fs

2016-12-08T06:16:18Z

commit c4fcfc1619ea43a8a89ad2f83ff23905eee088bd upstream. Handling of recursion in d_real() is completely broken. Recursion is only done in the 'inode != NULL' case. But when opening the file we have 'inode == NULL' hence d_real() will return an overlay dentry. This won't work since overlayfs doesn't define its own file operations, so all file ops will fail. Fix by doing the recursion first and the check against the inode second. Bash script to reproduce the issue written by Quentin: - 8< - - - - - 8< - - - - - 8< - - - - - 8< - - - - tmpdir=$(mktemp -d) pushd ${tmpdir} mkdir -p {upper,lower,work} echo -n 'rocks' > lower/ksplice mount -t overlay level_zero upper -o lowerdir=lower,upperdir=upper,workdir=work cat upper/ksplice tmpdir2=$(mktemp -d) pushd ${tmpdir2} mkdir -p {upper,work} mount -t overlay level_one upper -o lowerdir=${tmpdir}/upper,upperdir=upper,workdir=work ls -l upper/ksplice cat upper/ksplice - 8< - - - - - 8< - - - - - 8< - - - - - 8< - - - - Reported-by: Quentin Casasnovas Signed-off-by: Miklos Szeredi Fixes: 2d902671ce1c ("vfs: merge .d_select_inode() into .d_real()") Signed-off-by: Greg Kroah-Hartman

ovl: update S_ISGID when setting posix ACLs

2016-11-10T15:38:51Z

commit fd3220d37b1f6f0cab6142d98b0e6c4082e63299 upstream. This change fixes xfstest generic/375, which failed to clear the setgid bit in the following test case on overlayfs: touch $testfile chown 100:100 $testfile chmod 2755 $testfile _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile Reported-by: Amir Goldstein Signed-off-by: Miklos Szeredi Tested-by: Amir Goldstein Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Signed-off-by: Greg Kroah-Hartman

ovl: fix workdir creation

2016-09-05T11:55:20Z

Workdir creation fails in latest kernel. Fix by allowing EOPNOTSUPP as a valid return value from vfs_removexattr(XATTR_NAME_POSIX_ACL_*). Upper filesystem may not support ACL and still be perfectly able to support overlayfs. Reported-by: Martin Ziegler Signed-off-by: Miklos Szeredi Fixes: c11b9fdd6a61 ("ovl: remove posix_acl_default from workdir") Cc:

ovl: Switch to generic_getxattr

2016-09-01T09:12:00Z

Now that overlayfs has xattr handlers for iop->{set,remove}xattr, use those same handlers for iop->getxattr as well. Signed-off-by: Andreas Gruenbacher Signed-off-by: Miklos Szeredi

ovl: copyattr after setting POSIX ACL

2016-09-01T09:12:00Z

Setting POSIX acl may also modify the file mode, so need to copy that up to the overlay inode. Reported-by: Eryu Guan Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Signed-off-by: Miklos Szeredi

ovl: Switch to generic_removexattr

2016-09-01T09:12:00Z

Commit d837a49bd57f ("ovl: fix POSIX ACL setting") switches from iop->setxattr from ovl_setxattr to generic_setxattr, so switch from ovl_removexattr to generic_removexattr as well. As far as permission checking goes, the same rules should apply in either case. While doing that, rename ovl_setxattr to ovl_xattr_set to indicate that this is not an iop->setxattr implementation and remove the unused inode argument. Move ovl_other_xattr_set above ovl_own_xattr_set so that they match the order of handlers in ovl_xattr_handlers. Signed-off-by: Andreas Gruenbacher Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Signed-off-by: Miklos Szeredi

ovl: Get rid of ovl_xattr_noacl_handlers array

2016-09-01T09:11:59Z

Use an ordinary #ifdef to conditionally include the POSIX ACL handlers in ovl_xattr_handlers, like the other filesystems do. Flag the code that is now only used conditionally with __maybe_unused. Signed-off-by: Andreas Gruenbacher Signed-off-by: Miklos Szeredi

ovl: fix spelling mistake: "directries" -> "directories"

2016-09-01T09:11:59Z

Trivial fix to spelling mistake in pr_err message. Signed-off-by: Colin Ian King Signed-off-by: Miklos Szeredi

ovl: proper cleanup of workdir

2016-09-01T09:11:59Z

When mounting overlayfs it needs a clean "work" directory under the supplied workdir. Previously the mount code removed this directory if it already existed and created a new one. If the removal failed (e.g. directory was not empty) then it fell back to a read-only mount not using the workdir. While this has never been reported, it is possible to get a non-empty "work" dir from a previous mount of overlayfs in case of crash in the middle of an operation using the work directory. In this case the left over state should be discarded and the overlay filesystem will be consistent, guaranteed by the atomicity of operations on moving to/from the workdir to the upper layer. This patch implements cleaning out any files left in workdir. It is implemented using real recursion for simplicity, but the depth is limited to 2, because the worst case is that of a directory containing whiteouts under "work". Signed-off-by: Miklos Szeredi Cc:

ovl: remove posix_acl_default from workdir

2016-09-01T09:11:59Z

Clear out posix acl xattrs on workdir and also reset the mode after creation so that an inherited sgid bit is cleared. Signed-off-by: Miklos Szeredi Cc: