tree 8841c80c9cf5873c915a821e98f3ae09746ec9d8
parent 9bc08a45fb117c696e4940cfa1208cb1cc7a2f25
author Dave Chinner <dchinner@redhat.com> 1283480373 +1000
committer Dave Chinner <david@fromorbit.com> 1283480373 +1000

xfs: prevent 32bit overflow in space reservation

If we attempt to preallocate more than 2^32 blocks of space in a
single syscall, the transaction block reservation will overflow
leading to a hangs in the superblock block accounting code. This
is trivially reproduced with xfs_io. Fix the problem by capping the
allocation reservation to the maximum number of blocks a single
xfs_bmapi() call can allocate (2^21 blocks).

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>