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9acb102522
Add a test that reproduces the stale ACL bug fixed by:
"fs: preserve ACL_DONT_CACHE state in forget_cached_acl()"
A FUSE mount that does not negotiate FUSE_POSIX_ACL initialises inodes
with i_acl = ACL_DONT_CACHE. Before the fix, calling
forget_all_cached_acls() (e.g. from fuse_update_get_attr() on a
statx(AT_STATX_FORCE_SYNC)) would silently replace ACL_DONT_CACHE with
ACL_NOT_CACHED, enabling the kernel ACL cache. A subsequent getxattr
would populate the cache, and because fuse_set_acl() skips
forget_all_cached_acls() for !fc->posix_acl, later ACL changes were
not visible to callers — getxattr returned stale data.
The test mounts a minimal libfuse3 lowlevel filesystem (no
FUSE_POSIX_ACL negotiated) and:
1. Issues two getxattrs — both must reach the daemon, proving
ACL_DONT_CACHE suppresses caching before any trigger.
2. Calls statx(AT_STATX_FORCE_SYNC) to trigger forget_all_cached_acls().
3. Issues another getxattr (populates the cache on a buggy kernel).
4. Switches the daemon to a different-sized ACL (ACL_B).
5. Issues a final getxattr — expects ACL_B (44 bytes) and daemon
call count 4; a buggy kernel returns stale ACL_A (28 bytes).
fuse_acl_cache_test is only built when libfuse3 is detected via
pkg-config.
Christian Brauner <brauner@kernel.org> says:
Changed do_force_statx() to call the statx() libc wrapper instead of
syscall(SYS_statx, ...) as requested by Amir after review feedback from
Luis Henriques, and dropped the now unused <sys/syscall.h> include.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://patch.msgid.link/20260713220932.413004-3-amir73il@gmail.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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| .. | ||
| binderfs | ||
| empty_mntns | ||
| epoll | ||
| eventfd | ||
| fat | ||
| fsmount_ns | ||
| fuse | ||
| mount-notify | ||
| move_mount | ||
| nsfs | ||
| open_tree_ns | ||
| openat2 | ||
| overlayfs | ||
| statmount | ||
| xattr | ||
| .gitignore | ||
| anon_inode_test.c | ||
| devpts_pts.c | ||
| dnotify_test.c | ||
| fclog.c | ||
| file_stressor.c | ||
| idmapped_tmpfile.c | ||
| kernfs_test.c | ||
| Makefile | ||
| utils.c | ||
| utils.h | ||
| wrappers.h | ||