JFFS2 does not appear to set s_bdi anywhere.  And as of 32a88aa1,
__sync_filesystem() will return 0 if s_bdi is not set.  As a result,
sync_fs() is never called for jffs2 and whatever remains in the wbuf
will not make it to the device.

Fix that up by assigning the mtd bdi.

Signed-off-by: Jörn Engel <joern@logfs.org>
Acked-By: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

simple_set_mnt() is defined as returning 'int' but always returns 0.
Callers assume simple_set_mnt() never fails and don't properly cleanup if
it were to _ever_ fail.  For instance, get_sb_single() and get_sb_nodev()
should:

        up_write(sb->s_unmount);
        deactivate_super(sb);

if simple_set_mnt() fails.

Since simple_set_mnt() never fails, would be cleaner if it did not
return anything.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

As reported by Adrian Bunk, commit d5686b444ff3f72808d2b3fbd58672a86cdf38e7
(switch mtd and dm-table to lookup_bdev()) causes the following compile
error with CONFIG_BLOCK=n:

  CC      drivers/mtd/mtdsuper.o
drivers/mtd/mtdsuper.c: In function `get_sb_mtd':
drivers/mtd/mtdsuper.c:184: error: implicit declaration of function 'lookup_bdev'
drivers/mtd/mtdsuper.c:184: warning: assignment makes pointer from integer without a cast
drivers/mtd/mtdsuper.c:197: error: implicit declaration of function 'bdput'
make[3]: *** [drivers/mtd/mtdsuper.o] Error 1

Fix it by putting the block device lookup inside #ifdef CONFIG_BLOCK

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

No need to open-code it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

* Add path_put() functions for releasing a reference to the dentry and
  vfsmount of a struct path in the right order

* Switch from path_release(nd) to path_put(&nd->path)

* Rename dput_path() to path_put_conditional()

[akpm@linux-foundation.org: fix cifs]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.

Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
  <dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
  struct path in every place where the stack can be traversed
- it reduces the overall code size:

without patch series:
   text    data     bss     dec     hex filename
5321639  858418  715768 6895825  6938d1 vmlinux

with patch series:
   text    data     bss     dec     hex filename
5320026  858418  715768 6894212  693284 vmlinux

This patch:

Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Initialise s_flags in get_sb_mtd_aux() from the flags parameter.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

It returns ERR_PTR(foo) on error, not just NULL.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Generalise the handling of MTD-specific superblocks so that JFFS2 and ROMFS
can both share it.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>