diff mbox series

[7/9] man: create a separate RESBLKS ioctl manpage

Message ID 156104949681.1174403.3533354992259074908.stgit@magnolia (mailing list archive)
State Accepted
Headers show
Series xfsprogs: document the ioctls scrub uses | expand

Commit Message

Darrick J. Wong June 20, 2019, 4:51 p.m. UTC 
From: Darrick J. Wong <darrick.wong@oracle.com>

Create a separate manual page for the xfs RESBLKS ioctls so we can
document how it works.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 man/man2/ioctl_xfs_getresblks.2 |   65 +++++++++++++++++++++++++++++++++++++++
 man/man2/ioctl_xfs_setresblks.2 |    1 +
 man/man3/xfsctl.3               |   14 +++++++-
 3 files changed, 78 insertions(+), 2 deletions(-)
 create mode 100644 man/man2/ioctl_xfs_getresblks.2
 create mode 100644 man/man2/ioctl_xfs_setresblks.2

Comments

Eric Sandeen July 5, 2019, 4:02 p.m. UTC | #1 
On 6/20/19 11:51 AM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Create a separate manual page for the xfs RESBLKS ioctls so we can
> document how it works.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  man/man2/ioctl_xfs_getresblks.2 |   65 +++++++++++++++++++++++++++++++++++++++
>  man/man2/ioctl_xfs_setresblks.2 |    1 +
>  man/man3/xfsctl.3               |   14 +++++++-
>  3 files changed, 78 insertions(+), 2 deletions(-)
>  create mode 100644 man/man2/ioctl_xfs_getresblks.2
>  create mode 100644 man/man2/ioctl_xfs_setresblks.2
> 
> 
> diff --git a/man/man2/ioctl_xfs_getresblks.2 b/man/man2/ioctl_xfs_getresblks.2
> new file mode 100644
> index 00000000..694b4496
> --- /dev/null
> +++ b/man/man2/ioctl_xfs_getresblks.2
> @@ -0,0 +1,65 @@
> +.\" Copyright (c) 2019, Oracle.  All rights reserved.
> +.\"
> +.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
> +.\" SPDX-License-Identifier: GPL-2.0+
> +.\" %%%LICENSE_END
> +.TH IOCTL-XFS-GETRESBLKS 2 2019-06-17 "XFS"
> +.SH NAME
> +ioctl_xfs_getresblks \- query XFS summary counter information
                                     ^^^^^^^^^^^^^^^

"query and set XFS free space reservation information"

> +.SH SYNOPSIS
> +.br
> +.B #include <xfs/xfs_fs.h>
> +.PP
> +.BI "int ioctl(int " fd ", XFS_IOC_GET_RESBLKS, struct xfs_fsop_resblks *" arg );
> +.br
> +.BI "int ioctl(int " fd ", XFS_IOC_SET_RESBLKS, struct xfs_fsop_resblks *" arg );
> +.SH DESCRIPTION

I wonder if starting with a "don't use" right here would be wise, something like:

"Note: This is a[n] test/debug ioctl intended only for use by XFS filesystem developers."

> +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 call these ioctls, because overriding the
> +defaults is extremely dangerous and should never be tried by anyone.
> +.PP
> +The reservation information is conveyed in a structure of the following form:
> +.PP
> +.in +4n
> +.nf
> +struct xfs_fsop_resblks {
> +	__u64  resblks;
> +	__u64  resblks_avail;
> +};
> +.fi
> +.in
> +.PP
> +.I resblks
> +is the number of blocks that the filesystem will try to maintain to prevent
> +critical out of space situations.
> +.PP
> +.I resblks_avail
> +is the number of reserved blocks remaining.
> +.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.
> +.TP
> +.B EPERM
> +Caller does not have permission to call this ioctl.
> +.SH CONFORMING TO
> +This API is specific to XFS filesystem on the Linux kernel.
> +.SH SEE ALSO
> +.BR ioctl (2)
> diff --git a/man/man2/ioctl_xfs_setresblks.2 b/man/man2/ioctl_xfs_setresblks.2
> new file mode 100644
> index 00000000..209bc0a8
> --- /dev/null
> +++ b/man/man2/ioctl_xfs_setresblks.2
> @@ -0,0 +1 @@
> +.so man2/ioctl_xfs_getresblks.2
> diff --git a/man/man3/xfsctl.3 b/man/man3/xfsctl.3
> index ee3188ec..89975a3c 100644
> --- a/man/man3/xfsctl.3
> +++ b/man/man3/xfsctl.3
> @@ -396,12 +396,21 @@ See
>  .BR ioctl_xfs_fscounts (2)
>  for more information.
>  
> +.TP
> +.nf
> +.B XFS_IOC_GET_RESBLKS
> +.fi
> +.TP
> +.B XFS_IOC_SET_RESBLKS
> +See
> +.BR ioctl_xfs_getresblks (2)
> +for more information.
> +Save yourself a lot of frustration and avoid these ioctls.
> +
>  .PP
>  .nf
>  .B XFS_IOC_THAW
>  .B XFS_IOC_FREEZE
> -.B XFS_IOC_GET_RESBLKS
> -.B XFS_IOC_SET_RESBLKS
>  .B XFS_IOC_FSGROWFSDATA
>  .B XFS_IOC_FSGROWFSLOG
>  .fi
> @@ -419,6 +428,7 @@ as they are not of general use to applications.
>  .BR ioctl_xfs_scrub_metadata (2),
>  .BR ioctl_xfs_fsinumbers (2),
>  .BR ioctl_xfs_fscounts (2),
> +.BR ioctl_xfs_getresblks (2),
>  .BR fstatfs (2),
>  .BR statfs (2),
>  .BR xfs (5),
>
Darrick J. Wong July 5, 2019, 5:09 p.m. UTC | #2 
On Fri, Jul 05, 2019 at 11:02:40AM -0500, Eric Sandeen wrote:
> On 6/20/19 11:51 AM, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > Create a separate manual page for the xfs RESBLKS ioctls so we can
> > document how it works.
> > 
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > ---
> >  man/man2/ioctl_xfs_getresblks.2 |   65 +++++++++++++++++++++++++++++++++++++++
> >  man/man2/ioctl_xfs_setresblks.2 |    1 +
> >  man/man3/xfsctl.3               |   14 +++++++-
> >  3 files changed, 78 insertions(+), 2 deletions(-)
> >  create mode 100644 man/man2/ioctl_xfs_getresblks.2
> >  create mode 100644 man/man2/ioctl_xfs_setresblks.2
> > 
> > 
> > diff --git a/man/man2/ioctl_xfs_getresblks.2 b/man/man2/ioctl_xfs_getresblks.2
> > new file mode 100644
> > index 00000000..694b4496
> > --- /dev/null
> > +++ b/man/man2/ioctl_xfs_getresblks.2
> > @@ -0,0 +1,65 @@
> > +.\" Copyright (c) 2019, Oracle.  All rights reserved.
> > +.\"
> > +.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
> > +.\" SPDX-License-Identifier: GPL-2.0+
> > +.\" %%%LICENSE_END
> > +.TH IOCTL-XFS-GETRESBLKS 2 2019-06-17 "XFS"
> > +.SH NAME
> > +ioctl_xfs_getresblks \- query XFS summary counter information
>                                      ^^^^^^^^^^^^^^^
> 
> "query and set XFS free space reservation information"

DOH.

Yes, thanks for fixing that. :)

> > +.SH SYNOPSIS
> > +.br
> > +.B #include <xfs/xfs_fs.h>
> > +.PP
> > +.BI "int ioctl(int " fd ", XFS_IOC_GET_RESBLKS, struct xfs_fsop_resblks *" arg );
> > +.br
> > +.BI "int ioctl(int " fd ", XFS_IOC_SET_RESBLKS, struct xfs_fsop_resblks *" arg );
> > +.SH DESCRIPTION
> 
> I wonder if starting with a "don't use" right here would be wise, something like:
> 
> "Note: This is a[n] test/debug ioctl intended only for use by XFS filesystem developers."

I'm partial to "This is an extraordinary way to eat your data!" :)

But yes it should have a warning label for SET_RESBLKS.

--D

> > +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 call these ioctls, because overriding the
> > +defaults is extremely dangerous and should never be tried by anyone.
> > +.PP
> > +The reservation information is conveyed in a structure of the following form:
> > +.PP
> > +.in +4n
> > +.nf
> > +struct xfs_fsop_resblks {
> > +	__u64  resblks;
> > +	__u64  resblks_avail;
> > +};
> > +.fi
> > +.in
> > +.PP
> > +.I resblks
> > +is the number of blocks that the filesystem will try to maintain to prevent
> > +critical out of space situations.
> > +.PP
> > +.I resblks_avail
> > +is the number of reserved blocks remaining.
> > +.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.
> > +.TP
> > +.B EPERM
> > +Caller does not have permission to call this ioctl.
> > +.SH CONFORMING TO
> > +This API is specific to XFS filesystem on the Linux kernel.
> > +.SH SEE ALSO
> > +.BR ioctl (2)
> > diff --git a/man/man2/ioctl_xfs_setresblks.2 b/man/man2/ioctl_xfs_setresblks.2
> > new file mode 100644
> > index 00000000..209bc0a8
> > --- /dev/null
> > +++ b/man/man2/ioctl_xfs_setresblks.2
> > @@ -0,0 +1 @@
> > +.so man2/ioctl_xfs_getresblks.2
> > diff --git a/man/man3/xfsctl.3 b/man/man3/xfsctl.3
> > index ee3188ec..89975a3c 100644
> > --- a/man/man3/xfsctl.3
> > +++ b/man/man3/xfsctl.3
> > @@ -396,12 +396,21 @@ See
> >  .BR ioctl_xfs_fscounts (2)
> >  for more information.
> >  
> > +.TP
> > +.nf
> > +.B XFS_IOC_GET_RESBLKS
> > +.fi
> > +.TP
> > +.B XFS_IOC_SET_RESBLKS
> > +See
> > +.BR ioctl_xfs_getresblks (2)
> > +for more information.
> > +Save yourself a lot of frustration and avoid these ioctls.
> > +
> >  .PP
> >  .nf
> >  .B XFS_IOC_THAW
> >  .B XFS_IOC_FREEZE
> > -.B XFS_IOC_GET_RESBLKS
> > -.B XFS_IOC_SET_RESBLKS
> >  .B XFS_IOC_FSGROWFSDATA
> >  .B XFS_IOC_FSGROWFSLOG
> >  .fi
> > @@ -419,6 +428,7 @@ as they are not of general use to applications.
> >  .BR ioctl_xfs_scrub_metadata (2),
> >  .BR ioctl_xfs_fsinumbers (2),
> >  .BR ioctl_xfs_fscounts (2),
> > +.BR ioctl_xfs_getresblks (2),
> >  .BR fstatfs (2),
> >  .BR statfs (2),
> >  .BR xfs (5),
> >
diff mbox series

Patch

diff --git a/man/man2/ioctl_xfs_getresblks.2 b/man/man2/ioctl_xfs_getresblks.2
new file mode 100644
index 00000000..694b4496
--- /dev/null
+++ b/man/man2/ioctl_xfs_getresblks.2
@@ -0,0 +1,65 @@ 
+.\" Copyright (c) 2019, Oracle.  All rights reserved.
+.\"
+.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
+.\" SPDX-License-Identifier: GPL-2.0+
+.\" %%%LICENSE_END
+.TH IOCTL-XFS-GETRESBLKS 2 2019-06-17 "XFS"
+.SH NAME
+ioctl_xfs_getresblks \- query XFS summary counter information
+.SH SYNOPSIS
+.br
+.B #include <xfs/xfs_fs.h>
+.PP
+.BI "int ioctl(int " fd ", XFS_IOC_GET_RESBLKS, struct xfs_fsop_resblks *" arg );
+.br
+.BI "int ioctl(int " fd ", XFS_IOC_SET_RESBLKS, struct xfs_fsop_resblks *" arg );
+.SH 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 call these ioctls, because overriding the
+defaults is extremely dangerous and should never be tried by anyone.
+.PP
+The reservation information is conveyed in a structure of the following form:
+.PP
+.in +4n
+.nf
+struct xfs_fsop_resblks {
+	__u64  resblks;
+	__u64  resblks_avail;
+};
+.fi
+.in
+.PP
+.I resblks
+is the number of blocks that the filesystem will try to maintain to prevent
+critical out of space situations.
+.PP
+.I resblks_avail
+is the number of reserved blocks remaining.
+.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.
+.TP
+.B EPERM
+Caller does not have permission to call this ioctl.
+.SH CONFORMING TO
+This API is specific to XFS filesystem on the Linux kernel.
+.SH SEE ALSO
+.BR ioctl (2)
diff --git a/man/man2/ioctl_xfs_setresblks.2 b/man/man2/ioctl_xfs_setresblks.2
new file mode 100644
index 00000000..209bc0a8
--- /dev/null
+++ b/man/man2/ioctl_xfs_setresblks.2
@@ -0,0 +1 @@ 
+.so man2/ioctl_xfs_getresblks.2
diff --git a/man/man3/xfsctl.3 b/man/man3/xfsctl.3
index ee3188ec..89975a3c 100644
--- a/man/man3/xfsctl.3
+++ b/man/man3/xfsctl.3
@@ -396,12 +396,21 @@  See
 .BR ioctl_xfs_fscounts (2)
 for more information.
 
+.TP
+.nf
+.B XFS_IOC_GET_RESBLKS
+.fi
+.TP
+.B XFS_IOC_SET_RESBLKS
+See
+.BR ioctl_xfs_getresblks (2)
+for more information.
+Save yourself a lot of frustration and avoid these ioctls.
+
 .PP
 .nf
 .B XFS_IOC_THAW
 .B XFS_IOC_FREEZE
-.B XFS_IOC_GET_RESBLKS
-.B XFS_IOC_SET_RESBLKS
 .B XFS_IOC_FSGROWFSDATA
 .B XFS_IOC_FSGROWFSLOG
 .fi
@@ -419,6 +428,7 @@  as they are not of general use to applications.
 .BR ioctl_xfs_scrub_metadata (2),
 .BR ioctl_xfs_fsinumbers (2),
 .BR ioctl_xfs_fscounts (2),
+.BR ioctl_xfs_getresblks (2),
 .BR fstatfs (2),
 .BR statfs (2),
 .BR xfs (5),