[GIT PULL 09/16] xfs: online repair of directories

["Darrick J. Wong" <djwong@kernel.org>]

Hi Chandan,

Please pull this branch with changes for xfs for 6.10-rc1.

As usual, I did a test-merge with the main upstream branch as of a few
minutes ago, and didn't see any conflicts.  Please let me know if you
encounter any problems.

--D

The following changes since commit 669dfe883c8e20231495f80a28ec7cc0b8fdddc4:

xfs: update the unlinked list when repairing link counts (2024-04-15 14:58:55 -0700)

are available in the Git repository at:

https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git tags/repair-dirs-6.10_2024-04-15

for you to fetch changes up to 34c9382c128270d0f4c8b36783b30f3c8085b2dd:

xfs: ask the dentry cache if it knows the parent of a directory (2024-04-15 14:58:56 -0700)

----------------------------------------------------------------
xfs: online repair of directories [v30.3 09/16]

This series employs atomic extent swapping to enable safe reconstruction
of directory data.  For now, XFS does not support reverse directory
links (aka parent pointers), so we can only salvage the dirents of a
directory and construct a new structure.

Directory repair therefore consists of five main parts:

First, we walk the existing directory to salvage as many entries as we
can, by adding them as new directory entries to the repair temp dir.

Second, we validate the parent pointer found in the directory.  If one
was not found, we scan the entire filesystem looking for a potential
parent.

Third, we use atomic extent swaps to exchange the entire data fork
between the two directories.

Fourth, we reap the old directory blocks as carefully as we can.

To wrap up the directory repair code, we need to add to the regular
filesystem the ability to free all the data fork blocks in a directory.
This does not change anything with normal directories, since they must
still unlink and shrink one entry at a time.  However, this will
facilitate freeing of partially-inactivated temporary directories during
log recovery.

The second half of this patchset implements repairs for the dotdot
entries of directories.  For now there is only rudimentary support for
this, because there are no directory parent pointers, so the best we can
do is scanning the filesystem and the VFS dcache for answers.

This has been running on the djcloud for months with no problems.  Enjoy!

Signed-off-by: Darrick J. Wong <djwong@kernel.org>

----------------------------------------------------------------
Darrick J. Wong (5):
xfs: inactivate directory data blocks
xfs: online repair of directories
xfs: scan the filesystem to repair a directory dotdot entry
xfs: online repair of parent pointers
xfs: ask the dentry cache if it knows the parent of a directory

fs/xfs/Makefile              |    3 +
fs/xfs/scrub/dir.c           |    9 +
fs/xfs/scrub/dir_repair.c    | 1402 ++++++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/findparent.c    |  448 ++++++++++++++
fs/xfs/scrub/findparent.h    |   50 ++
fs/xfs/scrub/inode_repair.c  |    5 +
fs/xfs/scrub/iscan.c         |   18 +-
fs/xfs/scrub/iscan.h         |    1 +
fs/xfs/scrub/nlinks.c        |   23 +
fs/xfs/scrub/nlinks_repair.c |    9 +
fs/xfs/scrub/parent.c        |   14 +-
fs/xfs/scrub/parent_repair.c |  234 +++++++
fs/xfs/scrub/readdir.c       |    7 +
fs/xfs/scrub/repair.c        |    1 +
fs/xfs/scrub/repair.h        |    8 +
fs/xfs/scrub/scrub.c         |    4 +-
fs/xfs/scrub/tempfile.c      |   13 +
fs/xfs/scrub/tempfile.h      |    2 +
fs/xfs/scrub/trace.h         |  115 ++++
fs/xfs/scrub/xfblob.h        |   24 +
fs/xfs/xfs_inode.c           |   51 ++
21 files changed, 2437 insertions(+), 4 deletions(-)
create mode 100644 fs/xfs/scrub/dir_repair.c
create mode 100644 fs/xfs/scrub/findparent.c
create mode 100644 fs/xfs/scrub/findparent.h
create mode 100644 fs/xfs/scrub/parent_repair.c