Hi all, It turns out that there are some serious bugs in how xfs handles the unlinked inode lists. Way back before 4.14, there was a bug where a ro mount of a dirty filesystem would recover the log bug neglect to purge the unlinked list. This leads to clean unmounted filesystems with unlinked inodes. Starting around 5.15, we also converted the codebase to maintain a doubly-linked incore unlinked list. However, we never provided the ability to load the incore list from disk. If someone tries to allocate an O_TMPFILE file on a clean fs with a pre-existing unlinked list or even deletes a file, the code will fail and the fs shuts down. This first part of the correction effort adds the ability to load the first inode in the bucket when unlinking a file; and to load the next inode in the list when inactivating (freeing) an inode. In userspace, we'll add a xfs_db command to create unlinked inodes on a (presumably) clean filesystem so that we can finally write some regression and functional testing of iunlink recovery to ensure that this all works properly. 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=fix-iunlink xfsprogs git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=fix-iunlink --- db/Makefile | 2 db/command.c | 1 db/command.h | 1 db/iunlink.c | 400 ++++++++++++++++++++++++++++++++++++++++++++++ libxfs/libxfs_api_defs.h | 2 man/man8/xfs_db.8 | 30 +++ 6 files changed, 435 insertions(+), 1 deletion(-) create mode 100644 db/iunlink.c
