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@xxxxxxxxxx> > > > > 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@xxxxxxxxxx> > > --- > > 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), > >
