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authorBreno Leitao <leitao@debian.org>2026-08-05 07:52:36 -0700
committerTejun Heo <tj@kernel.org>2026-08-10 11:47:20 -1000
commita5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656 (patch)
tree39f5b258386e1127d253d293194e9a2991bf3c34 /fs/verity/Kconfig
downloadlinux-stable-a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656.tar.gz
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workqueue: skip the node_nr_active update for non-unbound workqueuesgrafted
apply_wqattrs_commit() updates node_nr_active->max unconditionally. wq->node_nr_active[] is only allocated for unbound workqueues, so guard the call before per-cpu workqueues start using this path. No functional change: only unbound workqueues reach apply_wqattrs_*() today. Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Tejun Heo <tj@kernel.org>
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+# SPDX-License-Identifier: GPL-2.0
+
+config FS_VERITY
+ bool "FS Verity (read-only file-based authenticity protection)"
+ # Filesystems cache the Merkle tree at a 64K aligned offset in the
+ # pagecache. That approach assumes the page size is at most 64K.
+ depends on PAGE_SHIFT <= 16
+ select CRYPTO_HASH_INFO
+ select CRYPTO_LIB_SHA256
+ select CRYPTO_LIB_SHA512
+ help
+ This option enables fs-verity. fs-verity is the dm-verity
+ mechanism implemented at the file level. On supported
+ filesystems (currently ext4, f2fs, and btrfs), userspace can
+ use an ioctl to enable verity for a file, which causes the
+ filesystem to build a Merkle tree for the file. The filesystem
+ will then transparently verify any data read from the file
+ against the Merkle tree. The file is also made read-only.
+
+ This serves as an integrity check, but the availability of the
+ Merkle tree root hash also allows efficiently supporting
+ various use cases where normally the whole file would need to
+ be hashed at once, such as: (a) auditing (logging the file's
+ hash), or (b) authenticity verification (comparing the hash
+ against a known good value, e.g. from a digital signature).
+
+ fs-verity is especially useful on large files where not all
+ the contents may actually be needed. Also, fs-verity verifies
+ data each time it is paged back in, which provides better
+ protection against malicious disks vs. an ahead-of-time hash.
+
+ If unsure, say N.
+
+config FS_VERITY_BUILTIN_SIGNATURES
+ bool "FS Verity builtin signature support"
+ depends on FS_VERITY
+ select SYSTEM_DATA_VERIFICATION
+ help
+ This option adds support for in-kernel verification of
+ fs-verity builtin signatures.
+
+ Please take great care before using this feature. It is not
+ the only way to do signatures with fs-verity, and the
+ alternatives (such as userspace signature verification, and
+ IMA appraisal) can be much better. For details about the
+ limitations of this feature, see
+ Documentation/filesystems/fsverity.rst.
+
+ If unsure, say N.