Hi all, This series implements online checking and repair for directory parent pointer metadata. The checking half is fairly straightforward -- for each outgoing directory link (forward or backwards), grab the inode at the other end, and confirm that there's a corresponding link. If we can't grab an inode or lock it, we'll save that link for a slower loop that cycles all the locks, confirms the continued existence of the link, and rechecks the link if it's actually still there. Repairs are a bit more involved -- for directories, we walk the entire filesystem to rebuild the dirents from parent pointer information. Parent pointer repairs do the same walk but rebuild the pptrs from the dirent information, but with the added twist that it duplicates all the xattrs so that it can use the atomic extent swapping code to commit the repairs atomically. This introduces an added twist to the xattr repair code -- we use dirent hooks to detect a colliding update to the pptr data while we're not holding the ILOCKs; if one is detected, we restart the xattr salvaging process but this time hold all the ILOCKs until the end of the scan. For offline repair, the phase6 directory connectivity scan generates an index of all the expected parent pointers in the filesystem. Then it walks each file and compares the parent pointers attached to that file against the index generated, and resyncs the results as necessary. The last patch teaches xfs_scrub to report pathnames of files that are being repaired, when possible. If you're going to start using this code, I strongly recommend pulling from my git trees, which are linked below. This has been running on the djcloud for months with no problems. Enjoy! Comments and questions are, as always, welcome. kernel git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-pptrs-6.10 xfsprogs git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=repair-pptrs-6.10 --- Commits in this patchset: * xfs_db: remove some boilerplate from xfs_attr_set * xfs_db: actually report errors from libxfs_attr_set * xfs_repair: junk parent pointer attributes when filesystem doesn't support them * xfs_repair: add parent pointers when messing with /lost+found * xfs_repair: junk duplicate hashtab entries when processing sf dirents * xfs_repair: build a parent pointer index * xfs_repair: move the global dirent name store to a separate object * xfs_repair: deduplicate strings stored in string blob * xfs_repair: check parent pointers * xfs_repair: dump garbage parent pointer attributes * xfs_repair: update ondisk parent pointer records * xfs_repair: wipe ondisk parent pointers when there are none --- db/attrset.c | 36 + libxfs/libxfs_api_defs.h | 6 libxfs/xfblob.c | 9 libxfs/xfblob.h | 2 repair/Makefile | 6 repair/attr_repair.c | 30 + repair/listxattr.c | 271 +++++++++ repair/listxattr.h | 15 + repair/phase6.c | 121 ++++ repair/pptr.c | 1331 ++++++++++++++++++++++++++++++++++++++++++++++ repair/pptr.h | 17 + repair/strblobs.c | 211 +++++++ repair/strblobs.h | 24 + 13 files changed, 2069 insertions(+), 10 deletions(-) create mode 100644 repair/listxattr.c create mode 100644 repair/listxattr.h create mode 100644 repair/pptr.c create mode 100644 repair/pptr.h create mode 100644 repair/strblobs.c create mode 100644 repair/strblobs.h
