[00/18] btrfs: fixes, cleanups and optimizations around fiemap

Message

Filipe Manana Oct. 10, 2022, 10:22 a.m. UTC

From: Filipe Manana <[e-mail]>

The first two patches are bug fixes, the first one fixing a bug in backref
walking that has been around for 5 years, while the second one fixes a bug
introduced in this merge window.

The remaining are performance optimizations in the fiemap code path, as
well as some cleanups and refactorings to support them. Results and tests
are found in the changelogs of individual patches (05/18, 15/18, 17/18
and 18/18).

Filipe Manana (18):
  btrfs: fix processing of delayed tree block refs during backref walking
  btrfs: ignore fiemap path cache if we have multiple leaves for a data extent
  btrfs: get the next extent map during fiemap/lseek more efficiently
  btrfs: skip unnecessary extent map searches during fiemap and lseek
  btrfs: skip unnecessary delalloc search during fiemap and lseek
  btrfs: drop pointless memset when cloning extent buffer
  btrfs: drop redundant bflags initialization when allocating extent buffer
  btrfs: remove checks for a root with id 0 during backref walking
  btrfs: remove checks for a 0 inode number during backref walking
  btrfs: directly pass the inode to btrfs_is_data_extent_shared()
  btrfs: turn the backref sharedness check cache into a context object
  btrfs: move ulists to data extent sharedness check context
  btrfs: remove roots ulist when checking data extent sharedness
  btrfs: remove useless logic when finding parent nodes
  btrfs: cache sharedness of the last few data extents during fiemap
  btrfs: move up backref sharedness cache store and lookup functions
  btrfs: avoid duplicated resolution of indirect backrefs during fiemap
  btrfs: avoid unnecessary resolution of indirect backrefs during fiemap

 fs/btrfs/backref.c    | 462 ++++++++++++++++++++++++++++--------------
 fs/btrfs/backref.h    |  55 ++++-
 fs/btrfs/extent_io.c  |  68 +++----
 fs/btrfs/extent_map.c |  31 ++-
 fs/btrfs/extent_map.h |   2 +
 fs/btrfs/file.c       |  69 +++++--
 6 files changed, 462 insertions(+), 225 deletions(-)