vfs: add missing checks to copy_file_range

Like the clone and dedupe interfaces we've recently fixed, the
copy_file_range() implementation is missing basic sanity, limits and
boundary condition tests on the parameters that are passed to it
from userspace. Create a new "generic_copy_file_checks()" function
modelled on the generic_remap_checks() function to provide this
missing functionality.

[Amir] Shorten copy length instead of checking pos_in limits
because input file size already abides by the limits.

Signed-off-by: Dave Chinner <[email protected]>
Signed-off-by: Amir Goldstein <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: Darrick J. Wong <[email protected]>

0 files changed, 0 insertions, 0 deletions