ioctl_fslabel - Man Page
get or set a filesystem label
Library
Standard C library (libc, -lc)
Synopsis
#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
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
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.
Standards
Linux.
History
Linux 4.18.
They were previously known as BTRFS_IOC_GET_FSLABEL and BTRFS_IOC_SET_FSLABEL and were private to Btrfs.
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.