ioctl_xfs_getresblks(2) — Linux manual page
IOCTL-XFS-GETRESBLKS(2) System Calls Manual IOCTL-XFS-GETRESBLKS(2)
NAME
ioctl_xfs_getresblks - query and set XFS free space reservation
information
SYNOPSIS
#include <xfs/xfs_fs.h>
int ioctl(int fd, XFS_IOC_GET_RESBLKS, struct xfs_fsop_resblks
*arg);
int ioctl(int fd, XFS_IOC_SET_RESBLKS, struct xfs_fsop_resblks
*arg);
DESCRIPTION
Query or set the free space reservation information. These
blocks are reserved by the filesystem as a final attempt to
prevent metadata update failures due to insufficient space. Only
the system administrator can use these ioctls, because overriding
the defaults is extremely dangerous.
This functionality is intended only for use by XFS filesystem
developers.
The reservation information is conveyed in a structure of the
following form:
struct xfs_fsop_resblks {
__u64 resblks;
__u64 resblks_avail;
};
resblks is the number of blocks that the filesystem will try to
maintain to prevent critical out of space situations.
resblks_avail is the number of reserved blocks remaining.
RETURN VALUE
On error, -1 is returned, and errno is set to indicate the error.
ERRORS
Error codes can be one of, but are not limited to, the following:
EFSBADCRC
Metadata checksum validation failed while performing the
query.
EFSCORRUPTED
Metadata corruption was encountered while performing the
query.
EINVAL The specified allocation group number is not valid for
this filesystem.
EIO An I/O error was encountered while performing the query.
EPERM Caller does not have permission to call this ioctl.
CONFORMING TO
This API is specific to XFS filesystem on the Linux kernel.
SEE ALSO
ioctl(2)
COLOPHON
This page is part of the xfsprogs (utilities for XFS filesystems)
project. Information about the project can be found at
⟨http://xfs.org/⟩. If you have a bug report for this manual page,
send it to linux-xfs@vger.kernel.org. This page was obtained
from the project's upstream Git repository
⟨https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-05-17.) If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for
the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original
manual page), send a mail to man-pages@man7.org
XFS 2019-06-17 IOCTL-XFS-GETRESBLKS(2)
Pages that refer to this page: xfsctl(3)