From: Miklos Szeredi <[email protected]> commit e8b20a474cf2c42698d1942f939ff2128819f151 upstream.
The command mount -o remount -o unknownoption /mnt/fuse succeeds on kernel versions prior to v5.4 and fails on kernel version at or after. This is because fuse_parse_param() rejects any unrecognised options in case of FS_CONTEXT_FOR_RECONFIGURE, just as for FS_CONTEXT_FOR_MOUNT. This causes a regression in case the fuse filesystem is in fstab, since remount sends all options found there to the kernel; even ones that are meant for the initial mount and are consumed by the userspace fuse server. Fix this by ignoring mount options, just as fuse_remount_fs() did prior to the conversion to the new API. Reported-by: Stefan Priebe <[email protected]> Fixes: c30da2e981a7 ("fuse: convert to use the new mount API") Cc: <[email protected]> # v5.4 Signed-off-by: Miklos Szeredi <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/fuse/inode.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -468,6 +468,13 @@ static int fuse_parse_param(struct fs_co struct fuse_fs_context *ctx = fc->fs_private; int opt; + /* + * Ignore options coming from mount(MS_REMOUNT) for backward + * compatibility. + */ + if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) + return 0; + opt = fs_parse(fc, fuse_fs_parameters, param, &result); if (opt < 0) return opt;
