Commit a2a4dc49 authored Apr 03, 2014 by Thomas Bächler Committed by Greg Kroah-Hartman Apr 16, 2014

fs: Don't return 0 from get_anon_bdev

Commit 9e30cc95 removed an internal mount. This
has the side-effect that rootfs now has FSID 0. Many
userspace utilities assume that st_dev in struct stat
is never 0, so this change breaks a number of tools in
early userspace.

Since we don't know how many userspace programs are affected,
make sure that FSID is at least 1.

References: http://article.gmane.org/gmane.linux.kernel/1666905
References: http://permalink.gmane.org/gmane.linux.utilities.util-linux-ng/8557


Cc: 3.14 <stable@vger.kernel.org>
Signed-off-by: Thomas Bächler <thomas@archlinux.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Tested-by: Alexandre Demers <alexandre.f.demers@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent c9eaa447

fs/super.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -800,7 +800,10 @@ void emergency_remount(void)

		static DEFINE_IDA(unnamed_dev_ida);
		static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
		static int unnamed_dev_start = 0; /* don't bother trying below it */
		/* Many userspace utilities consider an FSID of 0 invalid.
		* Always return at least 1 from get_anon_bdev.
		*/
		static int unnamed_dev_start = 1;

		int get_anon_bdev(dev_t *p)
		{