tree 61ccc6ad01f8804d5290ae4565ba8d4238bf648a
parent 3ee690143c3c99f6c0e83f08ff17556890bc6027
author Eric W. Biederman <ebiederm@xmission.com> 1465504442 -0500
committer Eric W. Biederman <ebiederm@xmission.com> 1466714517 -0500

vfs: Generalize filesystem nodev handling.

Introduce a function may_open_dev that tests MNT_NODEV and a new
superblock flab SB_I_NODEV.  Use this new function in all of the
places where MNT_NODEV was previously tested.

Add the new SB_I_NODEV s_iflag to proc, sysfs, and mqueuefs as those
filesystems should never support device nodes, and a simple superblock
flags makes that very hard to get wrong.  With SB_I_NODEV set if any
device nodes somehow manage to show up on on a filesystem those
device nodes will be unopenable.

Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>