linux-toradex.git/include/linux/fsverity.h, branch v7.0-rc6

fsverity: fix build error by adding fsverity_readahead() stub

2026-02-18T07:11:40+00:00

hppa-linux-gcc 9.5.0 generates a call to fsverity_readahead() in
f2fs_readahead() when CONFIG_FS_VERITY=n, because it fails to do the
expected dead code elimination based on vi always being NULL.  Fix the
build error by adding an inline stub for fsverity_readahead().  Since
it's just for opportunistic readahead, just make it a no-op.

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202602180838.pwICdY2r-lkp@intel.com/
Fixes: 45dcb3ac9832 ("f2fs: consolidate fsverity_info lookup")
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20260218012244.18536-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers

fsverity: remove fsverity_verify_page()

2026-02-18T07:11:36+00:00

Now that fsverity_verify_page() has no callers, remove it.

Suggested-by: Linus Torvalds 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20260218010630.7407-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers

fsverity: use a hashtable to find the fsverity_info

2026-02-04T19:31:54+00:00

Use the kernel's resizable hash table (rhashtable) to find the
fsverity_info.  This way file systems that want to support fsverity don't
have to bloat every inode in the system with an extra pointer.  The
trade-off is that looking up the fsverity_info is a bit more expensive
now, but the main operations are still dominated by I/O and hashing
overhead.

The rhashtable implementations requires no external synchronization, and
the _fast versions of the APIs provide the RCU critical sections required
by the implementation.  Because struct fsverity_info is only removed on
inode eviction and does not contain a reference count, there is no need
for an extended critical section to grab a reference or validate the
object state.  The file open path uses rhashtable_lookup_get_insert_fast,
which can either find an existing object for the hash key or insert a
new one in a single atomic operation, so that concurrent opens never
instantiate duplicate fsverity_info structure.  FS_IOC_ENABLE_VERITY must
already be synchronized by a combination of i_rwsem and file system flags
and uses rhashtable_lookup_insert_fast, which errors out on an existing
object for the hash key as an additional safety check.

Because insertion into the hash table now happens before S_VERITY is set,
fsverity just becomes a barrier and a flag check and doesn't have to look
up the fsverity_info at all, so there is only a single lookup per
->read_folio or ->readahead invocation.  For btrfs there is an additional
one for each bio completion, while for ext4 and f2fs the fsverity_info
is stored in the per-I/O context and reused for the completion workqueue.

Signed-off-by: Christoph Hellwig 
Reviewed-by: "Darrick J. Wong" 
Link: https://lore.kernel.org/r/20260202060754.270269-12-hch@lst.de
[EB: folded in fix for missing fsverity_free_info()]
Signed-off-by: Eric Biggers

fsverity: push out fsverity_info lookup

2026-02-03T01:15:26+00:00

Pass a struct fsverity_info to the verification and readahead helpers,
and push the lookup into the callers.  Right now this is a very dumb
almost mechanic move that open codes a lot of fsverity_info_addr() calls
in the file systems.  The subsequent patches will clean this up.

This prepares for reducing the number of fsverity_info lookups, which
will allow to amortize them better when using a more expensive lookup
method.

Signed-off-by: Christoph Hellwig 
Reviewed-by: "Darrick J. Wong" 
Acked-by: David Sterba  # btrfs
Link: https://lore.kernel.org/r/20260202060754.270269-7-hch@lst.de
Signed-off-by: Eric Biggers

fsverity: kick off hash readahead at data I/O submission time

2026-02-03T01:15:26+00:00

Currently all reads of the fsverity hashes are kicked off from the data
I/O completion handler, leading to needlessly dependent I/O.  This is
worked around a bit by performing readahead on the level 0 nodes, but
still fairly ineffective.

Switch to a model where the ->read_folio and ->readahead methods instead
kick off explicit readahead of the fsverity hashed so they are usually
available at I/O completion time.

For 64k sequential reads on my test VM this improves read performance
from 2.4GB/s - 2.6GB/s to 3.5GB/s - 3.9GB/s.  The improvements for
random reads are likely to be even bigger.

Signed-off-by: Christoph Hellwig 
Acked-by: David Sterba  # btrfs
Link: https://lore.kernel.org/r/20260202060754.270269-5-hch@lst.de
Signed-off-by: Eric Biggers

fsverity: start consolidating pagecache code

2026-01-29T17:39:41+00:00

ext4 and f2fs are largely using the same code to read a page full
of Merkle tree blocks from the page cache, and the upcoming xfs
fsverity support would add another copy.

Move the ext4 code to fs/verity/ and use it in f2fs as well.  For f2fs
this removes the previous f2fs-specific error injection, but otherwise
the behavior remains unchanged.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Andrey Albershteyn 
Reviewed-by: Jan Kara 
Reviewed-by: "Darrick J. Wong" 
Link: https://lore.kernel.org/r/20260128152630.627409-7-hch@lst.de
Signed-off-by: Eric Biggers

fsverity: pass struct file to ->write_merkle_tree_block

2026-01-29T17:39:41+00:00

This will make an iomap implementation of the method easier.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Andrey Albershteyn 
Reviewed-by: "Darrick J. Wong" 
Acked-by: David Sterba  # btrfs
Link: https://lore.kernel.org/r/20260128152630.627409-6-hch@lst.de
Signed-off-by: Eric Biggers

fs,fsverity: clear out fsverity_info from common code

2026-01-29T17:39:41+00:00

Free the fsverity_info directly in clear_inode instead of requiring file
systems to handle it.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jan Kara 
Reviewed-by: "Darrick J. Wong" 
Acked-by: David Sterba  # btrfs
Link: https://lore.kernel.org/r/20260128152630.627409-3-hch@lst.de
Signed-off-by: Eric Biggers

fs,fsverity: reject size changes on fsverity files in setattr_prepare

2026-01-29T17:39:41+00:00

Add the check to reject truncates of fsverity files directly to
setattr_prepare instead of requiring the file system to handle it.
Besides removing boilerplate code, this also fixes the complete lack of
such check in btrfs.

Fixes: 146054090b08 ("btrfs: initial fsverity support")
Signed-off-by: Christoph Hellwig 
Reviewed-by: Jan Kara 
Reviewed-by: "Darrick J. Wong" 
Link: https://lore.kernel.org/r/20260128152630.627409-2-hch@lst.de
Signed-off-by: Eric Biggers

fsverity: check IS_VERITY() in fsverity_cleanup_inode()

2025-08-21T11:58:08+00:00

Since getting the address of the fsverity_info has gotten a bit more
expensive, make fsverity_cleanup_inode() check for IS_VERITY() instead.
This avoids adding more overhead to non-verity files.

This assumes that verity info is never set when !IS_VERITY(), which is
currently true, but add a VFS_WARN_ON_ONCE() that asserts that.  (This
of course defeats the optimization, but only when CONFIG_VFS_DEBUG=y.)

Signed-off-by: Eric Biggers 
Link: https://lore.kernel.org/20250810075706.172910-14-ebiggers@kernel.org
Signed-off-by: Christian Brauner