On 9/3/19 11:37 PM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Document the new ioctl to describe an allocation group's geometry.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Ok - it's kind of interesting to get back EFSCORRUPTED failure from an
ioctl that is designed to report corruption details, but that detail can
be fleshed out more later.
Reviewed-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> ---
> man/man2/ioctl_xfs_ag_geometry.2 | 82 ++++++++++++++++++++++++++++++++++++++
> man/man3/xfsctl.3 | 6 +++
> 2 files changed, 88 insertions(+)
> create mode 100644 man/man2/ioctl_xfs_ag_geometry.2
>
>
> diff --git a/man/man2/ioctl_xfs_ag_geometry.2 b/man/man2/ioctl_xfs_ag_geometry.2
> new file mode 100644
> index 00000000..ddd54265
> --- /dev/null
> +++ b/man/man2/ioctl_xfs_ag_geometry.2
> @@ -0,0 +1,82 @@
> +.\" Copyright (c) 2019, Oracle. All rights reserved.
> +.\"
> +.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
> +.\" SPDX-License-Identifier: GPL-2.0+
> +.\" %%%LICENSE_END
> +.TH IOCTL-XFS-AG-GEOMETRY 2 2019-08-30 "XFS"
> +.SH NAME
> +ioctl_xfs_ag_geometry \- query XFS allocation group geometry information
> +.SH SYNOPSIS
> +.br
> +.B #include <xfs/xfs_fs.h>
> +.PP
> +.BI "int ioctl(int " fd ", XFS_IOC_AG_GEOMETRY, struct xfs_ag_geometry *" arg );
> +.SH DESCRIPTION
> +This XFS ioctl retrieves the geometry information for a given allocation group.
> +The geometry information is conveyed in a structure of the following form:
> +.PP
> +.in +4n
> +.nf
> +struct xfs_ag_geometry {
> + uint32_t ag_number;
> + uint32_t ag_length;
> + uint32_t ag_freeblks;
> + uint32_t ag_icount;
> + uint32_t ag_ifree;
> + uint32_t ag_sick;
> + uint32_t ag_checked;
> + uint32_t ag_flags;
> + uint64_t ag_reserved[12];
> +};
> +.fi
> +.in
> +.TP
> +.I ag_number
> +The caller must set this field to the index of the allocation group that the
> +caller wishes to learn about.
> +.TP
> +.I ag_length
> +The length of the allocation group is returned in this field, in units of
> +filesystem blocks.
> +.TP
> +.I ag_freeblks
> +The number of free blocks in the allocation group is returned in this field, in
> +units of filesystem blocks.
> +.TP
> +.I ag_icount
> +The number of inode records allocated in this allocation group is returned in
> +this field.
> +.TP
> +.I ag_ifree
> +The number of unused inode records (of the space allocated) in this allocation
> +group is returned in this field.
> +.TP
> +.I ag_flags
> +The caller can set this field to change the operational behavior of the ioctl.
> +Currently no flags are defined, so this field must be zero.
> +.TP
> +.IR ag_reserved
> +All reserved fields will be set to zero on return.
> +.SH RETURN VALUE
> +On error, \-1 is returned, and
> +.I errno
> +is set to indicate the error.
> +.PP
> +.SH ERRORS
> +Error codes can be one of, but are not limited to, the following:
> +.TP
> +.B EFSBADCRC
> +Metadata checksum validation failed while performing the query.
> +.TP
> +.B EFSCORRUPTED
> +Metadata corruption was encountered while performing the query.
> +.TP
> +.B EINVAL
> +The specified allocation group number is not valid for this filesystem.
> +.TP
> +.B EIO
> +An I/O error was encountered while performing the query.
> +.SH CONFORMING TO
> +This API is specific to XFS filesystem on the Linux kernel.
> +.SH SEE ALSO
> +.BR ioctl (2)
> diff --git a/man/man3/xfsctl.3 b/man/man3/xfsctl.3
> index 7e6588b8..dfebd12d 100644
> --- a/man/man3/xfsctl.3
> +++ b/man/man3/xfsctl.3
> @@ -336,6 +336,12 @@ See
> .BR ioctl_xfs_fsop_geometry (2)
> for more information.
>
> +.TP
> +.B XFS_IOC_AG_GEOMETRY
> +See
> +.BR ioctl_xfs_ag_geometry (2)
> +for more information.
> +
> .TP
> .BR XFS_IOC_FSBULKSTAT " or " XFS_IOC_FSBULKSTAT_SINGLE
> See
>
