[PATCH v5 00/24] fs-verity support for XFS

Andrey Albershteyn
2024-03-04T19:12:15Z

Hi all,

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

kernel:
[1]: https://github.com/alberand/linux/tree/fsverity-v5

xfsprogs:
[2]: https://github.com/alberand/xfsprogs/tree/fsverity-v5

xfstests:
[3]: https://github.com/alberand/xfstests/tree/fsverity-v5

v1:
[4]: https://lore.kernel.org/linux-xfs/20221213172935.680971-1-aalbersh@redhat.com/

v2:
[5]: https://lore.kernel.org/linux-xfs/20230404145319.2057051-1-aalbersh@redhat.com/

v3:
[6]: https://lore.kernel.org/all/20231006184922.252188-1-aalbersh@redhat.com/

v4:
[7]: https://lore.kernel.org/linux-xfs/20240212165821.1901300-1-aalbersh@redhat.com/

fs-verity:
[7]: https://www.kernel.org/doc/html/latest/filesystems/fsverity.html

Thanks,
Andrey

Allison Henderson (3):
xfs: add parent pointer support to attribute code
xfs: define parent pointer ondisk extended attribute format
xfs: add parent pointer validator functions

Andrey Albershteyn (21):
fsverity: remove hash page spin lock
fs: add FS_XFLAG_VERITY for verity files
fsverity: pass tree_blocksize to end_enable_verity()
fsverity: support block-based Merkle tree caching
fsverity: add per-sb workqueue for post read processing
fsverity: add tracepoints
iomap: integrate fs-verity verification into iomap's read path
xfs: add XBF_VERITY_SEEN xfs_buf flag
xfs: add XFS_DA_OP_BUFFER to make xfs_attr_get() return buffer
xfs: add attribute type for fs-verity
xfs: make xfs_buf_get() to take XBF_* flags
xfs: add XBF_DOUBLE_ALLOC to increase size of the buffer
xfs: add fs-verity ro-compat flag
xfs: add inode on-disk VERITY flag
xfs: initialize fs-verity on file open and cleanup on inode
destruction
xfs: don't allow to enable DAX on fs-verity sealsed inode
xfs: disable direct read path for fs-verity files
xfs: add fs-verity support
xfs: make scrub aware of verity dinode flag
xfs: add fs-verity ioctls
xfs: enable ro-compat fs-verity flag

Documentation/filesystems/fsverity.rst | 8 +
MAINTAINERS | 1 +
fs/btrfs/verity.c | 4 +-
fs/ext4/verity.c | 3 +-
fs/f2fs/verity.c | 3 +-
fs/ioctl.c | 11 +
fs/iomap/buffered-io.c | 92 ++++++-
fs/super.c | 7 +
fs/verity/enable.c | 9 +-
fs/verity/fsverity_private.h | 11 +-
fs/verity/init.c | 1 +
fs/verity/open.c | 9 +-
fs/verity/read_metadata.c | 64 +++--
fs/verity/signature.c | 2 +
fs/verity/verify.c | 180 +++++++++----
fs/xfs/Makefile | 2 +
fs/xfs/libxfs/xfs_attr.c | 31 ++-
fs/xfs/libxfs/xfs_attr.h | 3 +-
fs/xfs/libxfs/xfs_attr_leaf.c | 24 +-
fs/xfs/libxfs/xfs_attr_remote.c | 39 ++-
fs/xfs/libxfs/xfs_btree_mem.c | 2 +-
fs/xfs/libxfs/xfs_da_btree.h | 5 +-
fs/xfs/libxfs/xfs_da_format.h | 68 ++++-
fs/xfs/libxfs/xfs_format.h | 14 +-
fs/xfs/libxfs/xfs_log_format.h | 2 +
fs/xfs/libxfs/xfs_ondisk.h | 4 +
fs/xfs/libxfs/xfs_parent.c | 113 ++++++++
fs/xfs/libxfs/xfs_parent.h | 19 ++
fs/xfs/libxfs/xfs_sb.c | 4 +-
fs/xfs/scrub/attr.c | 4 +-
fs/xfs/xfs_attr_item.c | 6 +-
fs/xfs/xfs_attr_list.c | 14 +-
fs/xfs/xfs_buf.c | 6 +-
fs/xfs/xfs_buf.h | 23 +-
fs/xfs/xfs_file.c | 23 +-
fs/xfs/xfs_inode.c | 2 +
fs/xfs/xfs_inode.h | 3 +-
fs/xfs/xfs_ioctl.c | 22 ++
fs/xfs/xfs_iops.c | 4 +
fs/xfs/xfs_mount.h | 2 +
fs/xfs/xfs_super.c | 12 +
fs/xfs/xfs_trace.h | 4 +-
fs/xfs/xfs_verity.c | 355 +++++++++++++++++++++++++
fs/xfs/xfs_verity.h | 33 +++
fs/xfs/xfs_xattr.c | 10 +
include/linux/fs.h | 2 +
include/linux/fsverity.h | 91 ++++++-
include/trace/events/fsverity.h | 181 +++++++++++++
include/uapi/linux/fs.h | 1 +
49 files changed, 1395 insertions(+), 138 deletions(-)
create mode 100644 fs/xfs/libxfs/xfs_parent.c
create mode 100644 fs/xfs/libxfs/xfs_parent.h
create mode 100644 fs/xfs/xfs_verity.c
create mode 100644 fs/xfs/xfs_verity.h
create mode 100644 include/trace/events/fsverity.h

--
2.42.0