f2fs: support FS_IOC_{GET,SET}FSLABEL
Support two generic fs ioctls FS_IOC_{GET,SET}FSLABEL, letting
f2fs pass generic/492 testcase.
Fixes were made by Eric where:
- f2fs: fix buffer overruns in FS_IOC_{GET, SET}FSLABEL
utf16s_to_utf8s() and utf8s_to_utf16s() take the number of characters,
not the number of bytes.
- f2fs: fix copying too many bytes in FS_IOC_SETFSLABEL
Userspace provides a null-terminated string, so don't assume that the
full FSLABEL_MAX bytes can always be copied.
- f2fs: add missing authorization check in FS_IOC_SETFSLABEL
FS_IOC_SETFSLABEL modifies the filesystem superblock, so it shouldn't be
allowed to regular users. Require CAP_SYS_ADMIN, like xfs and btrfs do.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2 files changed