splice: move permission hook out of splice_file_to_pipe()

vfs_splice_read() has a permission hook inside rw_verify_area() and
it is called from splice_file_to_pipe(), which is called from
do_splice() and do_sendfile().

do_sendfile() already has a rw_verify_area() check for the entire range.
do_splice() has a rw_verify_check() for the splice to file case, not for
the splice from file case.

Add the rw_verify_area() check for splice from file case in do_splice()
and use a variant of vfs_splice_read() without rw_verify_area() check
in splice_file_to_pipe() to avoid the redundant rw_verify_area() checks.

This is needed for fanotify "pre content" events.

Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: Amir Goldstein <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

0 files changed, 0 insertions, 0 deletions