btrfs: provide btrfs_page_clamp_*() helpers

In the coming subpage RW supports, there are a lot of page status update
calls which need to be converted to subpage compatible version, which
needs @start and @len.

Some call sites already have such @start/@len and are already in
page range, like various endio functions.

But there are also call sites which need to clamp the range for subpage
case, like btrfs_dirty_pagse() and __process_contig_pages().

Here we introduce new helpers, btrfs_page_clamp_*(), to do and only do the
clamp for subpage version.

Although in theory all existing btrfs_page_*() calls can be converted to
use btrfs_page_clamp_*() directly, but that would make us to do
unnecessary clamp operations.

Tested-by: Ritesh Harjani <[email protected]> # [ppc64]
Tested-by: Anand Jain <[email protected]> # [aarch64]
Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: Qu Wenruo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

0 files changed, 0 insertions, 0 deletions