ioctl_fslabel(2)

1ioctl_fslabel(2)              System Calls Manual             ioctl_fslabel(2)
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NAME

6       ioctl_fslabel - get or set a filesystem label
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LIBRARY

9       Standard C library (libc, -lc)
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SYNOPSIS

12       #include <linux/fs.h>       /* Definition of *FSLABEL* constants */
13       #include <sys/ioctl.h>
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15       int ioctl(int fd, FS_IOC_GETFSLABEL, char label[FSLABEL_MAX]);
16       int ioctl(int fd, FS_IOC_SETFSLABEL, char label[FSLABEL_MAX]);
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DESCRIPTION

19       If  a filesystem supports online label manipulation, these ioctl(2) op‐
20       erations can be used to  get  or  set  the  filesystem  label  for  the
21       filesystem  on  which  fd resides.  The FS_IOC_SETFSLABEL operation re‐
22       quires privilege (CAP_SYS_ADMIN).
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RETURN VALUE

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

29       Possible errors include (but are not limited to) the following:
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31       EFAULT label references an inaccessible memory area.
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33       EINVAL The  specified  label  exceeds  the maximum label length for the
34              filesystem.
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36       ENOTTY This can appear if the filesystem does not support online  label
37              manipulation.
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39       EPERM  The  calling process does not have sufficient permissions to set
40              the label.
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STANDARDS

43       Linux.
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HISTORY

46       Linux 4.18.
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48       They   were   previously    known    as    BTRFS_IOC_GET_FSLABEL    and
49       BTRFS_IOC_SET_FSLABEL and were private to Btrfs.
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NOTES

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