tree 8c632478e9e5c0b0a2f9601542e54d8f02250cb1
parent 1c7878f024705594ac455e501ad51e475a400d5d
author Peter Osterlund <petero2@telia.com> 1116622746 -0700
committer Linus Torvalds <torvalds@ppc970.osdl.org> 1116629296 -0700

[PATCH] packet driver permission checking fix

If you tried to open a packet device first in read-only mode and then a
second time in read-write mode, the second open succeeded even though the
device was not correctly set up for writing.  If you then tried to write
data to the device, the writes would fail with I/O errors.

This patch prevents that problem by making the second open fail with
-EBUSY.

Signed-off-by: Peter Osterlund <petero2@telia.com>
Cc: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>