buffer: fix grow_buffers() for block size > PAGE_SIZE

We must not shift by a negative number so work in terms of a byte offset
to avoid the awkward shift left-or-right-depending-on-sign option.  This
means we need to use check_mul_overflow() to ensure that a large block
number does not result in a wrap.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Nathan Chancellor <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Pankaj Raghav <[email protected]>
Cc: Ryusuke Konishi <[email protected]>
[[email protected]: add cast in grow_buffers() to avoid a multiplication libcall]
  Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions