ioctl_fslabel(2) — Linux manual page


IOCTL_FSLABEL(2)        Linux Programmer's Manual       IOCTL_FSLABEL(2)

NAME         top

       ioctl_fslabel - get or set a filesystem label

SYNOPSIS         top

       #include <linux/fs.h>       /* Definition of *FSLABEL* constants */
       #include <sys/ioctl.h>

       int ioctl(int fd, FS_IOC_GETFSLABEL, char label[FSLABEL_MAX]);
       int ioctl(int fd, FS_IOC_SETFSLABEL, char label[FSLABEL_MAX]);

DESCRIPTION         top

       If a filesystem supports online label manipulation, these
       ioctl(2) operations can be used to get or set the filesystem
       label for the filesystem on which fd resides.  The
       FS_IOC_SETFSLABEL operation requires privilege (CAP_SYS_ADMIN).

RETURN VALUE         top

       On success zero is returned.  On error, -1 is returned, and errno
       is set to indicate the error.

ERRORS         top

       Possible errors include (but are not limited to) the following:

       EFAULT label references an inaccessible memory area.

       EINVAL The specified label exceeds the maximum label length for
              the filesystem.

       ENOTTY This can appear if the filesystem does not support online
              label manipulation.

       EPERM  The calling process does not have sufficient permissions
              to set the label.

VERSIONS         top

       These ioctl(2) operations first appeared in Linux 4.18.  They
       were previously known as BTRFS_IOC_GET_FSLABEL and
       BTRFS_IOC_SET_FSLABEL and were private to Btrfs.

CONFORMING TO         top

       This API is Linux-specific.

NOTES         top

       The maximum string length for this interface is FSLABEL_MAX,
       including the terminating null byte ('\0').  Filesystems have
       differing maximum label lengths, which may or may not include the
       terminating null.  The string provided to FS_IOC_SETFSLABEL must
       always be null-terminated, and the string returned by
       FS_IOC_GETFSLABEL will always be null-terminated.

SEE ALSO         top

       ioctl(2), blkid(8)

COLOPHON         top

       This page is part of release 5.13 of the Linux man-pages project.
       A description of the project, information about reporting bugs,
       and the latest version of this page, can be found at

Linux                          2021-03-22               IOCTL_FSLABEL(2)

Pages that refer to this page: ioctl(2)