[PATCH v2 0/5] btrfs: detect and fix the ram_bytes mismatch

[Qu Wenruo <wqu@suse.com>]

[CHANGELOG]
v2:
- Add the missing patch fixing ram_bytes
  Now the 2nd patch would ignore the incorrect value and use a correct
  one from btrfs_file_extent_item::disk_num_bytes.

- Update the commit messages to fix my usual "would" and other grammar
  errors

There is a long existing mismatch between ram_bytes and disk_num_bytes
for regular non-compressed data extents.

It turns out to be caused by truncated ordered extents, which modified
ram_bytes unnecessarily.

Thankfully this is not going to cause any data corruption or whatever,
kernel can handle it correctly without any extra problem.
It's only a small violation on the on-disk format.

This series would fix by:

- Cleanup the @bytenr usage inside btrfs_extent_item_to_extent_map()
- Override the ram_bytes when reading file extent items from disk
  So that we always get correct extent maps even if the on-disk one is
  incorrect.
- Add an extra check on extent_map members
- Add the proper fix for the ram_bytes mismatch
- Add a tree-checker for the ram_bytes mismatch
  Since we can have on-disk ram_bytes incorrect already, this check is
  only for DEBUG and ASSERT builds, and it won't report error but only
  does a kernel warning for us to catch.

Qu Wenruo (5):
  btrfs: cleanup the bytenr usage inside
    btrfs_extent_item_to_extent_map()
  btrfs: ignore incorrect btrfs_file_extent_item::ram_bytes
  btrfs: make validate_extent_map() to catch ram_bytes mismatch
  btrfs: fix the ram_bytes assignment for truncated ordered extents
  btrfs: tree-checker: add extra ram_bytes and disk_num_bytes check

 fs/btrfs/extent_map.c   |  5 +++++
 fs/btrfs/file-item.c    | 16 +++++++++++-----
 fs/btrfs/inode.c        |  4 +---
 fs/btrfs/tree-checker.c | 18 ++++++++++++++++++
 4 files changed, 35 insertions(+), 8 deletions(-)

-- 
2.45.2