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) 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

       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  previously  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-terminated.

SEE ALSO

       ioctl(2), blkid(8)

COLOPHON

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Linux                                              2020-04-20                                   IOCTL_FSLABEL(2)