On Tue, Jun 28, 2022 at 10:45:42PM +0800, hexiaole wrote:
> From: hexiaole <hexiaole@xxxxxxxxxx>
>
> 1. Description
> libxfs/xfs_log_format.h declare 'di_nlink' as unsigned 32-bit integer:
>
> typedef struct xfs_icdinode {
> ...
> __uint32_t di_nlink; /* number of links to file */
> ...
> } xfs_icdinode_t;
>
> But logprint/log_misc.c use '%hd' to print 'di_nlink':
>
> void
> xlog_print_trans_inode_core(xfs_icdinode_t *ip)
> {
> ...
> printf(_("nlink %hd uid %d gid %d\n"),
> ip->di_nlink, ip->di_uid, ip->di_gid);
> ...
> }
>
> '%hd' can be 16-bit on many architectures, on these architectures, the 'printf' only print the low 16-bit of 'di_nlink'.
>
> 2. Reproducer
> 2.1. Commands
> [root@localhost ~]# cd
> [root@localhost ~]# xfs_mkfile 128m 128m.xfs
> [root@localhost ~]# mkfs.xfs 128m.xfs
> [root@localhost ~]# mount 128m.xfs /mnt/
> [root@localhost ~]# cd /mnt/
> [root@localhost mnt]# seq 1 65534|xargs mkdir -p
> [root@localhost mnt]# cd
> [root@localhost ~]# umount /mnt/
> [root@localhost ~]# xfs_logprint 128m.xfs|grep nlink|tail -1
>
> 2.2. Expect result
> nlink 65536
>
> 2.3. Actual result
> nlink 0
> ---
> logprint/log_misc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/logprint/log_misc.c b/logprint/log_misc.c
> index 35e926a3..6add28ed 100644
> --- a/logprint/log_misc.c
> +++ b/logprint/log_misc.c
> @@ -444,7 +444,7 @@ xlog_print_trans_inode_core(
> printf(_("magic 0x%hx mode 0%ho version %d format %d\n"),
> ip->di_magic, ip->di_mode, (int)ip->di_version,
> (int)ip->di_format);
> - printf(_("nlink %hd uid %d gid %d\n"),
> + printf(_("nlink %" PRIu32 " uid %d gid %d\n"),
*Half* decimal? LOL, I'd forgotten that even exists.
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> ip->di_nlink, ip->di_uid, ip->di_gid);
> printf(_("atime 0x%llx mtime 0x%llx ctime 0x%llx\n"),
> xlog_extract_dinode_ts(ip->di_atime),
> --
> 2.27.0
>
