It makes little sense for fsmount() to output the warning message when mount_too_revealing() is violated to kmsg. Instead, the warning should be output (with a "VFS" prefix) to the fscontext log. In addition, include the same log message for mount_too_revealing() when doing a regular mount for consistency. With the newest fsopen()-based mount(8) from util-linux, the error messages now look like # mount -t proc proc /tmp mount: /tmp: fsmount() failed: VFS: Mount too revealing. dmesg(1) may have more information after failed mount system call. which could finally result in mount_too_revealing() errors being easier for users to detect and understand. Signed-off-by: Aleksa Sarai <cyphar@xxxxxxxxxx> --- Changes in v2: - Log before setting retval. [Al Viro] - v1: <https://lore.kernel.org/r/20250806-errorfc-mount-too-revealing-v1-0-536540f51560@xxxxxxxxxx> --- Aleksa Sarai (2): fscontext: add custom-prefix log helpers vfs: output mount_too_revealing() errors to fscontext fs/namespace.c | 6 ++++-- include/linux/fs_context.h | 18 ++++++++++++++---- 2 files changed, 18 insertions(+), 6 deletions(-) --- base-commit: 66639db858112bf6b0f76677f7517643d586e575 change-id: 20250805-errorfc-mount-too-revealing-5d9f670ba770 Best regards, -- Aleksa Sarai <cyphar@xxxxxxxxxx>
