On Fri, Aug 07, 2020 at 12:59:00PM -0700, jo...@armadilloaerospace.com wrote:
> Perform an explicit check for the unsupported exFAT MSDOS filesystem
> instead of letting it fail mysteriously when it gets cluster sizes
> of 0 from the normal fields.
>
> This causes mount_msdos to report:
> mount_msdos: /dev/sd1i on /root/mnt: filesystem not supported by kernel
>
> Instead of the more obscure:
> mount_msdos: /dev/sd1i on /root/mnt: Inapropriate file type or format
>
> Index: msdosfs_vfsops.c
> ===================================================================
> RCS file: /cvs/src/sys/msdosfs/msdosfs_vfsops.c,v
> retrieving revision 1.93
> diff -u -p -r1.93 msdosfs_vfsops.c
> --- msdosfs_vfsops.c 24 Jan 2020 03:49:34 -0000 1.93
> +++ msdosfs_vfsops.c 7 Aug 2020 19:52:04 -0000
> @@ -298,6 +298,12 @@ msdosfs_mountfs(struct vnode *devvp, str
> b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
> b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
>
> + /* No support for exFAT filesystems */
> + if (!strncmp("EXFAT", bsp->bs33.bsOemName, 5)) {
> + error = EOPNOTSUPP;
> + goto error_exit;
> + }
> +
> pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK | M_ZERO);
> pmp->pm_mountp = mp;
The microsoft specification states it is EXFAT followed by three spaces
if (!memcmp("EXFAT ", bsp->bs33.bsOemName, 8)) {
may be more suitable here.
fsck_msdos(8) likely needs a change to bail early if exFAT is found as
well.
