NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | SEE ALSO | COLOPHON

IOCTL-XFS-GETRESBLKS(2)      System Calls Manual     IOCTL-XFS-GETRESBLKS(2)

NAME         top

       ioctl_xfs_getresblks  -  query  and  set  XFS  free space reservation
       information

SYNOPSIS         top

       #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         top

       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         top

       On error, -1 is returned, and errno is set to indicate the error.

ERRORS         top

       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         top

       This API is specific to XFS filesystem on the Linux kernel.

SEE ALSO         top

       ioctl(2)

COLOPHON         top

       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
       2019-07-28.  (At that time, the date of the most recent commit that
       was found in the repository was 2019-07-19.)  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)