commit 31abdab9c1 upstream.
For one thing, there's an ABBA deadlock on hpfs fs-wide lock and i_mutex
in hpfs_dir_lseek() - there's a lot of methods that grab the former with
the caller already holding the latter, so it must take i_mutex first.
For another, locking the damn thing, carefully validating the offset,
then dropping locks and assigning the offset is obviously racy.
Moreover, we _must_ do hpfs_add_pos(), or the machinery in dnode.c
won't modify the sucker on B-tree surgeries.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
d5c20298b6