If an external device is used for a journal, by default it will use the
entire device.  The reiserfs journal code allocates structures per journal
block when it mounts the file system.  If the journal device is too large,
and memory cannot be allocated for the structures, it will continue and
ultimately panic when it can't pull one off the free list.

This patch handles the allocation failure gracefully and prints an error
message at mount time.

Changes: Updated error message to be more descriptive to the user.

Discussed and approved on ReiserFS Mailing List, Nov 28.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>