diff mbox series

[9/9] man: create a separate xfs shutdown ioctl manpage

Message ID 156104950912.1174403.4990641877651635072.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 shutdown ioctl so we can
document how it works.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 man/man2/ioctl_xfs_goingdown.2 |   63 ++++++++++++++++++++++++++++++++++++++++
 man/man3/xfsctl.3              |    7 ++++
 2 files changed, 70 insertions(+)
 create mode 100644 man/man2/ioctl_xfs_goingdown.2

Comments

Eric Sandeen July 5, 2019, 4:08 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 shutdown ioctl so we can
> document how it works.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  man/man2/ioctl_xfs_goingdown.2 |   63 ++++++++++++++++++++++++++++++++++++++++
>  man/man3/xfsctl.3              |    7 ++++
>  2 files changed, 70 insertions(+)
>  create mode 100644 man/man2/ioctl_xfs_goingdown.2
> 
> 
> diff --git a/man/man2/ioctl_xfs_goingdown.2 b/man/man2/ioctl_xfs_goingdown.2
> new file mode 100644
> index 00000000..bedc85c8
> --- /dev/null
> +++ b/man/man2/ioctl_xfs_goingdown.2
> @@ -0,0 +1,63 @@
> +.\" Copyright (c) 2019, Oracle.  All rights reserved.
> +.\"
> +.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
> +.\" SPDX-License-Identifier: GPL-2.0+
> +.\" %%%LICENSE_END
> +.TH IOCTL-XFS-GOINGDOWN 2 2019-06-17 "XFS"
> +.SH NAME
> +ioctl_xfs_goingdown \- shut down an XFS filesystem
> +.SH SYNOPSIS
> +.br
> +.B #include <xfs/xfs_fs.h>
> +.PP
> +.BI "int ioctl(int " fd ", XFS_IOC_GOINGDOWN, uint32_t " flags );
> +.SH DESCRIPTION
> +Shuts down a live XFS filesystem.
> +This is a software initiated hard shutdown and should be avoided whenever
> +possible.
> +After this call completes, the filesystem will be totally unusable and must be
> +unmounted.

That almost sounds permanently destructive.  Perhaps:

"... will be totally unusable until the filesystem has been unmounted and remounted."

?

> +
> +.PP
> +.I flags
> +can be one of the following:
> +.RS 0.4i
> +.TP
> +.B XFS_FSOP_GOING_FLAGS_DEFAULT
> +Flush all dirty data and in-core state to disk, flush pending transactions to
> +the log, and shut down.

What exactly do we mean by "in-core state" here?  I'm not sure the average
reader will know (I'm not sure I know)

> +.TP
> +.B XFS_FSOP_GOING_FLAGS_LOGFLUSH
> +Flush all pending transactions to the log and shut down, leaving all dirty
> +data unwritten.
> +.TP
> +.B XFS_FSOP_GOING_FLAGS_NOLOGFLUSH
> +Shut down immediately, without writing pending transactions or dirty data
> +to disk.
> +
> +.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:

Hm crud, now I wonder about auditing all your stated error codes.
EPERM, EFAULT, and EINVAL seem to be the only options for this
particular call.  Maybe that can be a 2nd cleanup, documenting
an error code that won't happen is harmless...

> +.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 did not have permission to shut down the filesystem.
> +.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 077dd411..7e6588b8 100644
> --- a/man/man3/xfsctl.3
> +++ b/man/man3/xfsctl.3
> @@ -365,6 +365,12 @@ See
>  for more information.
>  Save yourself a lot of frustration and avoid these ioctls.
>  
> +.TP
> +.B XFS_IOC_GOINGDOWN
> +See
> +.BR ioctl_xfs_goingdown (2)
> +for more information.
> +
>  .PP
>  .nf
>  .B XFS_IOC_THAW
> @@ -388,6 +394,7 @@ as they are not of general use to applications.
>  .BR ioctl_xfs_fscounts (2),
>  .BR ioctl_xfs_getresblks (2),
>  .BR ioctl_xfs_getbmap (2),
> +.BR ioctl_xfs_goingdown (2),
>  .BR fstatfs (2),
>  .BR statfs (2),
>  .BR xfs (5),
>
Darrick J. Wong July 5, 2019, 5:13 p.m. UTC | #2 
On Fri, Jul 05, 2019 at 11:08:54AM -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 shutdown ioctl so we can
> > document how it works.
> > 
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > ---
> >  man/man2/ioctl_xfs_goingdown.2 |   63 ++++++++++++++++++++++++++++++++++++++++
> >  man/man3/xfsctl.3              |    7 ++++
> >  2 files changed, 70 insertions(+)
> >  create mode 100644 man/man2/ioctl_xfs_goingdown.2
> > 
> > 
> > diff --git a/man/man2/ioctl_xfs_goingdown.2 b/man/man2/ioctl_xfs_goingdown.2
> > new file mode 100644
> > index 00000000..bedc85c8
> > --- /dev/null
> > +++ b/man/man2/ioctl_xfs_goingdown.2
> > @@ -0,0 +1,63 @@
> > +.\" Copyright (c) 2019, Oracle.  All rights reserved.
> > +.\"
> > +.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
> > +.\" SPDX-License-Identifier: GPL-2.0+
> > +.\" %%%LICENSE_END
> > +.TH IOCTL-XFS-GOINGDOWN 2 2019-06-17 "XFS"
> > +.SH NAME
> > +ioctl_xfs_goingdown \- shut down an XFS filesystem
> > +.SH SYNOPSIS
> > +.br
> > +.B #include <xfs/xfs_fs.h>
> > +.PP
> > +.BI "int ioctl(int " fd ", XFS_IOC_GOINGDOWN, uint32_t " flags );
> > +.SH DESCRIPTION
> > +Shuts down a live XFS filesystem.
> > +This is a software initiated hard shutdown and should be avoided whenever
> > +possible.
> > +After this call completes, the filesystem will be totally unusable and must be
> > +unmounted.
> 
> That almost sounds permanently destructive.  Perhaps:
> 
> "... will be totally unusable until the filesystem has been unmounted and remounted."
> 
> ?

Sounds good to me.

> > +
> > +.PP
> > +.I flags
> > +can be one of the following:
> > +.RS 0.4i
> > +.TP
> > +.B XFS_FSOP_GOING_FLAGS_DEFAULT
> > +Flush all dirty data and in-core state to disk, flush pending transactions to
> > +the log, and shut down.
> 
> What exactly do we mean by "in-core state" here?  I'm not sure the average
> reader will know (I'm not sure I know)

Hm... really it's any dirty cached state, like ... unflushed inodes and
dquots, dirty file data, etc.  I didn't want to commit to that level of
specificity though.

> > +.TP
> > +.B XFS_FSOP_GOING_FLAGS_LOGFLUSH
> > +Flush all pending transactions to the log and shut down, leaving all dirty
> > +data unwritten.
> > +.TP
> > +.B XFS_FSOP_GOING_FLAGS_NOLOGFLUSH
> > +Shut down immediately, without writing pending transactions or dirty data
> > +to disk.
> > +
> > +.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:
> 
> Hm crud, now I wonder about auditing all your stated error codes.
> EPERM, EFAULT, and EINVAL seem to be the only options for this
> particular call.  Maybe that can be a 2nd cleanup, documenting
> an error code that won't happen is harmless...

<urk> Ok, I'll go do that. :)

> > +.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.

This one definitely was copypasta error. :(

--D

> > +.TP
> > +.B EIO
> > +An I/O error was encountered while performing the query.
> > +.TP
> > +.B EPERM
> > +Caller did not have permission to shut down the filesystem.
> > +.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 077dd411..7e6588b8 100644
> > --- a/man/man3/xfsctl.3
> > +++ b/man/man3/xfsctl.3
> > @@ -365,6 +365,12 @@ See
> >  for more information.
> >  Save yourself a lot of frustration and avoid these ioctls.
> >  
> > +.TP
> > +.B XFS_IOC_GOINGDOWN
> > +See
> > +.BR ioctl_xfs_goingdown (2)
> > +for more information.
> > +
> >  .PP
> >  .nf
> >  .B XFS_IOC_THAW
> > @@ -388,6 +394,7 @@ as they are not of general use to applications.
> >  .BR ioctl_xfs_fscounts (2),
> >  .BR ioctl_xfs_getresblks (2),
> >  .BR ioctl_xfs_getbmap (2),
> > +.BR ioctl_xfs_goingdown (2),
> >  .BR fstatfs (2),
> >  .BR statfs (2),
> >  .BR xfs (5),
> >
Eric Sandeen July 5, 2019, 5:58 p.m. UTC | #3 
On 7/5/19 12:13 PM, Darrick J. Wong wrote:
> On Fri, Jul 05, 2019 at 11:08:54AM -0500, Eric Sandeen wrote:
>> On 6/20/19 11:51 AM, Darrick J. Wong wrote:
>>> From: Darrick J. Wong <darrick.wong@oracle.com>

...

 
>>> +
>>> +.PP
>>> +.I flags
>>> +can be one of the following:
>>> +.RS 0.4i
>>> +.TP
>>> +.B XFS_FSOP_GOING_FLAGS_DEFAULT
>>> +Flush all dirty data and in-core state to disk, flush pending transactions to
>>> +the log, and shut down.
>>
>> What exactly do we mean by "in-core state" here?  I'm not sure the average
>> reader will know (I'm not sure I know)
> 
> Hm... really it's any dirty cached state, like ... unflushed inodes and
> dquots, dirty file data, etc.  I didn't want to commit to that level of
> specificity though.

"Flush all dirty data and metadata to disk, flush pending transactions
to the log, and shut down." ?

>>> +.TP
>>> +.B XFS_FSOP_GOING_FLAGS_LOGFLUSH
>>> +Flush all pending transactions to the log and shut down, leaving all dirty
>>> +data unwritten.
>>> +.TP
>>> +.B XFS_FSOP_GOING_FLAGS_NOLOGFLUSH
>>> +Shut down immediately, without writing pending transactions or dirty data
>>> +to disk.
>>> +
>>> +.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:
>>
>> Hm crud, now I wonder about auditing all your stated error codes.
>> EPERM, EFAULT, and EINVAL seem to be the only options for this
>> particular call.  Maybe that can be a 2nd cleanup, documenting
>> an error code that won't happen is harmless...
> 
> <urk> Ok, I'll go do that. :)
> 
>>> +.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.
> 
> This one definitely was copypasta error. :(

Oh oopsies.  Ok that's worth fixing ....

-Eric
diff mbox series

Patch

diff --git a/man/man2/ioctl_xfs_goingdown.2 b/man/man2/ioctl_xfs_goingdown.2
new file mode 100644
index 00000000..bedc85c8
--- /dev/null
+++ b/man/man2/ioctl_xfs_goingdown.2
@@ -0,0 +1,63 @@ 
+.\" Copyright (c) 2019, Oracle.  All rights reserved.
+.\"
+.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
+.\" SPDX-License-Identifier: GPL-2.0+
+.\" %%%LICENSE_END
+.TH IOCTL-XFS-GOINGDOWN 2 2019-06-17 "XFS"
+.SH NAME
+ioctl_xfs_goingdown \- shut down an XFS filesystem
+.SH SYNOPSIS
+.br
+.B #include <xfs/xfs_fs.h>
+.PP
+.BI "int ioctl(int " fd ", XFS_IOC_GOINGDOWN, uint32_t " flags );
+.SH DESCRIPTION
+Shuts down a live XFS filesystem.
+This is a software initiated hard shutdown and should be avoided whenever
+possible.
+After this call completes, the filesystem will be totally unusable and must be
+unmounted.
+
+.PP
+.I flags
+can be one of the following:
+.RS 0.4i
+.TP
+.B XFS_FSOP_GOING_FLAGS_DEFAULT
+Flush all dirty data and in-core state to disk, flush pending transactions to
+the log, and shut down.
+.TP
+.B XFS_FSOP_GOING_FLAGS_LOGFLUSH
+Flush all pending transactions to the log and shut down, leaving all dirty
+data unwritten.
+.TP
+.B XFS_FSOP_GOING_FLAGS_NOLOGFLUSH
+Shut down immediately, without writing pending transactions or dirty data
+to disk.
+
+.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 did not have permission to shut down the filesystem.
+.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 077dd411..7e6588b8 100644
--- a/man/man3/xfsctl.3
+++ b/man/man3/xfsctl.3
@@ -365,6 +365,12 @@  See
 for more information.
 Save yourself a lot of frustration and avoid these ioctls.
 
+.TP
+.B XFS_IOC_GOINGDOWN
+See
+.BR ioctl_xfs_goingdown (2)
+for more information.
+
 .PP
 .nf
 .B XFS_IOC_THAW
@@ -388,6 +394,7 @@  as they are not of general use to applications.
 .BR ioctl_xfs_fscounts (2),
 .BR ioctl_xfs_getresblks (2),
 .BR ioctl_xfs_getbmap (2),
+.BR ioctl_xfs_goingdown (2),
 .BR fstatfs (2),
 .BR statfs (2),
 .BR xfs (5),