Hi all, This series implements online 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. 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. --D kernel git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=repair-pptrs xfsprogs git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=repair-pptrs --- Commits in this patchset: * xfs: add xattr setname and removename functions for internal users * xfs: add raw parent pointer apis to support repair * xfs: repair directories by scanning directory parent pointers * xfs: implement live updates for directory repairs * xfs: replay unlocked parent pointer updates that accrue during xattr repair * xfs: repair directory parent pointers by scanning for dirents * xfs: implement live updates for parent pointer repairs * xfs: remove pointless unlocked assertion * xfs: split xfs_bmap_add_attrfork into two pieces * xfs: add a per-leaf block callback to xchk_xattr_walk * xfs: actually rebuild the parent pointer xattrs * xfs: adapt the orphanage code to handle parent pointers * xfs: repair link count of nondirectories after rebuilding parent pointers * xfs: inode repair should ensure there's an attr fork to store parent pointers --- fs/xfs/libxfs/xfs_attr.c | 230 +++++++ fs/xfs/libxfs/xfs_attr.h | 4 fs/xfs/libxfs/xfs_bmap.c | 38 - fs/xfs/libxfs/xfs_bmap.h | 3 fs/xfs/libxfs/xfs_dir2.c | 2 fs/xfs/libxfs/xfs_dir2.h | 2 fs/xfs/libxfs/xfs_parent.c | 64 ++ fs/xfs/libxfs/xfs_parent.h | 6 fs/xfs/scrub/attr.c | 2 fs/xfs/scrub/attr_repair.c | 459 +++++++++++++++ fs/xfs/scrub/attr_repair.h | 4 fs/xfs/scrub/dir_repair.c | 564 +++++++++++++++++- fs/xfs/scrub/findparent.c | 12 fs/xfs/scrub/findparent.h | 10 fs/xfs/scrub/inode_repair.c | 41 + fs/xfs/scrub/listxattr.c | 10 fs/xfs/scrub/listxattr.h | 4 fs/xfs/scrub/nlinks.c | 3 fs/xfs/scrub/orphanage.c | 38 + fs/xfs/scrub/orphanage.h | 3 fs/xfs/scrub/parent.c | 7 fs/xfs/scrub/parent_repair.c | 1301 ++++++++++++++++++++++++++++++++++++++++++ fs/xfs/scrub/scrub.c | 2 fs/xfs/scrub/trace.h | 115 ++++ 24 files changed, 2816 insertions(+), 108 deletions(-)
