Permalink
Browse files

init: don't try mounting device as nfs root unless type fully matches

commit 377485f upstream.

Currently, we'll try mounting any device who's major device number is
UNNAMED_MAJOR as NFS root.  This would happen for non-NFS devices as
well (such as 9p devices) but it wouldn't cause any issues since
mounting the device as NFS would fail quickly and the code proceeded to
doing the proper mount:

       [  101.522716] VFS: Unable to mount root fs via NFS, trying floppy.
       [  101.534499] VFS: Mounted root (9p filesystem) on device 0:18.

Commit 6829a048102a ("NFS: Retry mounting NFSROOT") introduced retries
when mounting NFS root, which means that now we don't immediately fail
and instead it takes an additional 90+ seconds until we stop retrying,
which has revealed the issue this patch fixes.

This meant that it would take an additional 90 seconds to boot when
we're not using a device type which gets detected in order before NFS.

This patch modifies the NFS type check to require device type to be
'Root_NFS' instead of requiring the device to have an UNNAMED_MAJOR
major.  This makes boot process cleaner since we now won't go through
the NFS mounting code at all when the device isn't an NFS root
("/dev/nfs").

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
  • Loading branch information...
1 parent 3d58692 commit 2693a093ac93a63749fd595cf4569495014ff1b3 @sashalevin sashalevin committed with bwhacks May 5, 2012
Showing with 1 addition and 1 deletion.
  1. +1 −1 init/do_mounts.c
View
@@ -470,7 +470,7 @@ void __init change_floppy(char *fmt, ...)
void __init mount_root(void)
{
#ifdef CONFIG_ROOT_NFS
- if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
+ if (ROOT_DEV == Root_NFS) {
if (mount_nfs_root())
return;

0 comments on commit 2693a09

Please sign in to comment.