ioctl_fslabel(2)

1IOCTL_FSLABEL(2)           Linux Programmer's Manual          IOCTL_FSLABEL(2)
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NAME

6       ioctl_fslabel - get or set a filesystem label
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SYNOPSIS

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

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

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

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

40       These ioctl(2) operations first appeared in Linux 4.18.  They were pre‐
41       viously  known  as  BTRFS_IOC_GET_FSLABEL and BTRFS_IOC_SET_FSLABEL and
42       were private to Btrfs.
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CONFORMING TO

45       This API is Linux-specific.
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NOTES

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

59       This  page  is  part of release 5.13 of the Linux man-pages project.  A
60       description of the project, information about reporting bugs,  and  the
61       latest     version     of     this    page,    can    be    found    at
62       https://www.kernel.org/doc/man-pages/.
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66Linux                             2021-03-22                  IOCTL_FSLABEL(2)