[PATCH v3 00/28] fs-verity support for XFS

Andrey Albershteyn
2023-10-06T18:53:14Z

Hi all,

Quite a long time passed by from v2 but this is v3 of fs-verity
support in XFS.

This patchset introduces fs-verity [6] support in 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 works with Merkle tree blocks instead of PAGE references
from filesystem
- Filesystem can supply bio_set and submit_io() to iomap for read
path
- In XFS, fs-verity metadata is stored in extended attributes
- Verification happens in iomap's read IO path (offloaded to
workqueue)
- New global XFS workqueue for verification processing
- Direct path and DAX are disabled for inodes with fs-verity
- Inodes with fs-verity have new on-disk diflag
- xfs_attr_get() can return a buffer with an extended attribute
- Each extended attribute has exactly one Merkle tree block
- xfs_buf with Merkle tree block allocates double memory and has
duplicate of the extended attribute data with leaf headers and
without
- xfs_buf tracks verified status of merkle tree block

The patchset consist of five parts:
- [1..4]: Patches from Parent Pointer patchset which add binary
xattr names with a few deps
- [5]: Patch which adds FS_XFLAG_VERITY to make verity exposed as
extended attribute flag
- [9..10]: Improvements to core fs-verity - mainly switch to blocks
management instead of pages
- [11..12]: Allow filesystem to provide submit_io() and bio_set in
read path
- [12..28]: Integration of fs-verity to xfs

Testing:
The patchset is tested with xfstests -g all (with exceptions) on
xfs_1k, xfs_4k, xfs_1k_quota, xfs_4k_quota, ext4_4k, and
ext4_4k_quota. With KMEMLEAK and KASAN enabled. Also, xfs_1k and
xfs_4k on a 64k pages.

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-v3

xfsprogs:
[2]: https://github.com/alberand/xfsprogs/tree/fsverity-v3

xfstests:
[3]: https://github.com/alberand/xfstests/tree/fsverity-v3

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/

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

Thanks,
Andrey

Allison Henderson (4):
xfs: Add new name to attri/d
xfs: add parent pointer support to attribute code
xfs: define parent pointer xattr format
xfs: Add xfs_verify_pptr

Andrey Albershteyn (24):
fs: add FS_XFLAG_VERITY for fs-verity sealed inodes
fsverity: add drop_page() callout
fsverity: always use bitmap to track verified status
fsverity: pass Merkle tree block size to ->read_merkle_tree_page()
fsverity: pass log_blocksize to end_enable_verity()
fsverity: operate with Merkle tree blocks instead of pages
iomap: pass readpage operation to read path
iomap: allow filesystem to implement read path verification
xfs: add XBF_VERITY_CHECKED xfs_buf flag
xfs: add XFS_DA_OP_BUFFER to make xfs_attr_get() return buffer
xfs: introduce workqueue for post read IO work
xfs: add bio_set and submit_io for ioend post-processing
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 sealed 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 | 9 +
fs/btrfs/verity.c | 7 +-
fs/erofs/data.c | 4 +-
fs/ext4/verity.c | 6 +-
fs/f2fs/verity.c | 6 +-
fs/gfs2/aops.c | 4 +-
fs/ioctl.c | 4 +
fs/iomap/buffered-io.c | 53 ++++-
fs/verity/enable.c | 6 +-
fs/verity/fsverity_private.h | 1 -
fs/verity/open.c | 64 +++---
fs/verity/read_metadata.c | 40 ++--
fs/verity/verify.c | 126 +++---------
fs/xfs/Makefile | 1 +
fs/xfs/libxfs/xfs_attr.c | 81 +++++++-
fs/xfs/libxfs/xfs_attr.h | 7 +-
fs/xfs/libxfs/xfs_attr_leaf.c | 24 ++-
fs/xfs/libxfs/xfs_attr_remote.c | 40 +++-
fs/xfs/libxfs/xfs_da_btree.h | 7 +-
fs/xfs/libxfs/xfs_da_format.h | 62 +++++-
fs/xfs/libxfs/xfs_format.h | 14 +-
fs/xfs/libxfs/xfs_log_format.h | 8 +-
fs/xfs/libxfs/xfs_sb.c | 4 +-
fs/xfs/scrub/attr.c | 4 +-
fs/xfs/xfs_aops.c | 84 +++++++-
fs/xfs/xfs_aops.h | 2 +
fs/xfs/xfs_attr_item.c | 142 +++++++++++---
fs/xfs/xfs_attr_item.h | 1 +
fs/xfs/xfs_attr_list.c | 17 +-
fs/xfs/xfs_buf.c | 7 +-
fs/xfs/xfs_buf.h | 21 +-
fs/xfs/xfs_file.c | 22 ++-
fs/xfs/xfs_inode.c | 2 +
fs/xfs/xfs_inode.h | 3 +-
fs/xfs/xfs_ioctl.c | 22 +++
fs/xfs/xfs_iomap.c | 3 +
fs/xfs/xfs_iops.c | 4 +
fs/xfs/xfs_linux.h | 1 +
fs/xfs/xfs_mount.h | 3 +
fs/xfs/xfs_ondisk.h | 4 +
fs/xfs/xfs_super.c | 28 ++-
fs/xfs/xfs_trace.h | 1 +
fs/xfs/xfs_verity.c | 257 +++++++++++++++++++++++++
fs/xfs/xfs_verity.h | 37 ++++
fs/xfs/xfs_xattr.c | 9 +
fs/zonefs/file.c | 4 +-
include/linux/fsverity.h | 129 ++++++++++++-
include/linux/iomap.h | 36 +++-
include/uapi/linux/fs.h | 1 +
49 files changed, 1170 insertions(+), 252 deletions(-)
create mode 100644 fs/xfs/xfs_verity.c
create mode 100644 fs/xfs/xfs_verity.h

--
2.40.1