diff options
| author | Christian Brauner <brauner@kernel.org> | 2026-04-27 10:26:03 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2026-05-11 23:13:01 +0200 |
| commit | dc4edae7f41dceb236553b61cda0383895293c90 (patch) | |
| tree | da4b78ba0fe6a7f9dc10728eb35656c1226a8930 /fs/sysfs | |
| parent | 672697c37c9dfe05aabfd44ccb51c2877deb524e (diff) | |
fs: move SB_I_USERNS_VISIBLE to FS_USERNS_MOUNT_RESTRICTED
Whether a filesystem's mounts need to undergo a visibility check in user
namespaces is a static property of the filesystem type, not a runtime
property of each superblock instance. Both proc and sysfs always set
SB_I_USERNS_VISIBLE on their superblocks unconditionally (sysfs does so
on first creation, and subsequent mounts reuse the same superblock).
Move this flag from sb->s_iflags (SB_I_USERNS_VISIBLE) to
file_system_type->fs_flags (FS_USERNS_MOUNT_RESTRICTED) so the intent
is expressed at the filesystem type level where it belongs.
All check sites are updated to test sb->s_type->fs_flags instead of
sb->s_iflags. The SB_I_NOEXEC and SB_I_NODEV flags remain on the
superblock as they are runtime properties set during fill_super.
Link: https://patch.msgid.link/72887c5b6204dc3adf5a53104f0be6bd8bc4f6cd.1777278334.git.legion@kernel.org
Reviewed-by: Aleksa Sarai <aleksa@amutable.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/sysfs')
| -rw-r--r-- | fs/sysfs/mount.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index b199e8ff79b1..b45ea5d511e7 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -32,8 +32,6 @@ static int sysfs_get_tree(struct fs_context *fc) if (ret) return ret; - if (kfc->new_sb_created) - fc->root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE; return 0; } @@ -93,7 +91,7 @@ static struct file_system_type sysfs_fs_type = { .name = "sysfs", .init_fs_context = sysfs_init_fs_context, .kill_sb = sysfs_kill_sb, - .fs_flags = FS_USERNS_MOUNT, + .fs_flags = FS_USERNS_MOUNT | FS_USERNS_MOUNT_RESTRICTED, }; int __init sysfs_init(void) |