The index on the page must be set before it is inserted in the radix
tree. Otherwise there is a small race which can occur during lookup
where the page can be found with the incorrect index. This will trigger
the BUG_ON() in brd_lookup_page().
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reported-by: Chris Wedgwood <cw@f00f.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dfd20b2b17