IOCTL_FSLABEL(2) Linux Programmer's Manual IOCTL_FSLABEL(2)
NAME
ioctl_fslabel - get or set a filesystem label
SYNOPSIS
#include <sys/ioctl.h>
#include <linux/fs.h>
int ioctl(int fd, FS_IOC_GETFSLABEL, char label[FSLABEL_MAX]);
int ioctl(int fd, FS_IOC_SETFSLABEL, char label[FSLABEL_MAX]);
DESCRIPTION
If a filesystem supports online label manipulation, these ioctl(2) op-
erations can be used to get or set the filesystem label for the
filesystem on which fd resides. The FS_IOC_SETFSLABEL operation re-
quires privilege (CAP_SYS_ADMIN).
RETURN VALUE
On success zero is returned. On error, -1 is returned, and errno is
set to indicate the error.
ERRORS
Error can 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
These ioctl(2) operations first appeared in Linux 4.18. They were pre-
viously known as BTRFS_IOC_GET_FSLABEL and BTRFS_IOC_SET_FSLABEL and
were private to Btrfs.
CONFORMING TO
This API is Linux-specific.
NOTES
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-termi-
nated.
SEE ALSO
ioctl(2), blkid(8)
COLOPHON
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latest version of this page, can be found at
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Linux 2020-04-20 IOCTL_FSLABEL(2)