Hi all, >From Darrick J. Wong: This v5.3 patchset builds upon v5.2 of Andrey's patchset to implement fsverity for XFS. The biggest thing that I didn't like in the v5 patchset is the abuse of the data device's buffer cache to store the incore version of the merkle tree blocks. Not only do verity state flags end up in xfs_buf, but the double-alloc flag wastes memory and doesn't remain internally consistent if the xattrs shift around. I replaced all of that with a per-inode xarray that indexes incore merkle tree blocks. For cache hits, this dramatically reduces the amount of work that xfs has to do to feed fsverity. The per-block overhead is much lower (8 bytes instead of ~300 for xfs_bufs), and we no longer have to entertain layering violations in the buffer cache. I also added a per-filesystem shrinker so that reclaim can cull cached merkle tree blocks, starting with the leaf tree nodes. I've also rolled in some changes recommended by the fsverity maintainer, fixed some organization and naming problems in the xfs code, fixed a collision in the xfs_inode iflags, and improved dead merkle tree cleanup per the discussion of the v5 series. At this point I'm happy enough with this code to start integrating and testing it in my trees, so it's time to send it out a coherent patchset for comments. For v5.3, I've added bits and pieces of online and offline repair support, reduced the size of partially filled merkle tree blocks by removing trailing zeroes, changed the xattr hash function to better avoid collisions between merkle tree keys, made the fsverity invalidation bitmap unnecessary, and made it so that we can save space on sparse verity files by not storing merkle tree blocks that hash totally zeroed data blocks. >From Andrey Albershteyn: Here's v5 of my patchset of adding fs-verity support to XFS. This implementation uses extended attributes to store fs-verity metadata. The Merkle tree blocks are stored in the remote extended attributes. The names are offsets into the tree. A few key points of this patchset: - fs-verity can work with Merkle tree blocks based caching (xfs) and PAGE caching (ext4, f2fs, btrfs) - iomap does fs-verity verification - In XFS, fs-verity metadata is stored in extended attributes - per-sb workqueue for verification processing - Inodes with fs-verity have new on-disk diflag - xfs_attr_get() can return a buffer with an extended attribute - xfs_buf can allocate double space for Merkle tree blocks. Part of the space is used to store the extended attribute data without leaf headers - xfs_buf tracks verified status of merkle tree blocks The patchset consists of five parts: - [1]: fs-verity spinlock removal pending in fsverity/for-next - [2..4]: Parent pointers adding binary xattr names - [5]: Expose FS_XFLAG_VERITY for fs-verity files - [6..9]: Changes to fs-verity core - [10]: Integrate fs-verity to iomap - [11-24]: Add fs-verity support to XFS Testing: The patchset is tested with xfstests -g verity on xfs_1k, xfs_4k, xfs_1k_quota, xfs_4k_quota, ext4_4k, and ext4_4k_quota. With KMEMLEAK and KASAN enabled. More testing on the way. Changes from V4: - Mainly fs-verity changes; removed unnecessary functions - Replace XFS workqueue with per-sb workqueue created in fsverity_set_ops() - Drop patch with readahead calculation in bytes Changes from V3: - redone changes to fs-verity core as previous version had an issue on ext4 - add blocks invalidation interface to fs-verity - move memory ordering primitives out of block status check to fs read block function - add fs-verity verification to iomap instead of general post read processing Changes from V2: - FS_XFLAG_VERITY extended attribute flag - Change fs-verity to use Merkle tree blocks instead of expecting PAGE references from filesystem - Change approach in iomap to filesystem provided bio_set and submit_io instead of just callouts to filesystem - Add possibility for xfs_buf allocate more space for fs-verity extended attributes - Make xfs_attr module to copy fs-verity blocks inside the xfs_buf, so XFS can get data without leaf headers - Add Merkle tree removal for error path - Makae scrub aware of new dinode flag Changes from V1: - Added parent pointer patches for easier testing - Many issues and refactoring points fixed from the V1 review - Adjusted for recent changes in fs-verity core (folios, non-4k) - Dropped disabling of large folios - Completely new fsverity patches (fix, callout, log_blocksize) - Change approach to verification in iomap to the same one as in write path. Callouts to fs instead of direct fs-verity use. - New XFS workqueue for post read folio verification - xfs_attr_get() can return underlying xfs_buf - xfs_bufs are marked with XBF_VERITY_CHECKED to track verified blocks 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=fsverity xfsprogs git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=fsverity fstests git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfstests-dev.git/log/?h=fsverity --- Commits in this patchset: * common/verity: enable fsverity for XFS * xfs/{021,122}: adapt to fsverity xattrs * common/populate: add verity files to populate xfs images --- common/populate | 21 +++++++++++++++++++++ common/verity | 29 ++++++++++++++++++++++++++++- tests/xfs/021 | 3 +++ tests/xfs/122.out | 1 + 4 files changed, 53 insertions(+), 1 deletion(-)
