diff mbox series

[8/8] libxfs: break out GETBMAP manpage

Message ID 155839434566.68923.8410471590238448158.stgit@magnolia (mailing list archive)
State Superseded
Headers show
Series xfsprogs: document the ioctls scrub uses | expand

Commit Message

Darrick J. Wong May 20, 2019, 11:19 p.m. UTC
From: Darrick J. Wong <darrick.wong@oracle.com>

Create a separate manual page for the BMAP ioctls so we can document how
they work.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 man/man2/ioctl_xfs_getbmap.2   |  165 ++++++++++++++++++++++++++++++++++++++++
 man/man2/ioctl_xfs_goingdown.2 |   61 +++++++++++++++
 man/man3/xfsctl.3              |   66 ++++------------
 3 files changed, 241 insertions(+), 51 deletions(-)
 create mode 100644 man/man2/ioctl_xfs_getbmap.2
 create mode 100644 man/man2/ioctl_xfs_goingdown.2
diff mbox series

Patch

diff --git a/man/man2/ioctl_xfs_getbmap.2 b/man/man2/ioctl_xfs_getbmap.2
new file mode 100644
index 00000000..5097173b
--- /dev/null
+++ b/man/man2/ioctl_xfs_getbmap.2
@@ -0,0 +1,165 @@ 
+.\" Copyright (c) 2019, Oracle.  All rights reserved.
+.\"
+.\" %%%LICENSE_START(GPLv2+_DOC_FULL)
+.\" SPDX-License-Identifier: GPL-2.0+
+.\" %%%LICENSE_END
+.TH IOCTL-XFS-GETBMAP 2 2019-04-11 "XFS"
+.SH NAME
+ioctl_xfs_getbmap \- query extent information for an open file
+.SH SYNOPSIS
+.br
+.B #include <xfs/xfs_fs.h>
+.PP
+.BI "int ioctl(int " fd ", XFS_IOC_GETBMAP, struct getbmap *" arg );
+.PP
+.BI "int ioctl(int " fd ", XFS_IOC_GETBMAPA, struct getbmap *" arg );
+.PP
+.BI "int ioctl(int " fd ", XFS_IOC_GETBMAPX, struct getbmapx *" arg );
+.SH DESCRIPTION
+Get the block map for a segment of a file in an XFS file system.
+The mapping information is conveyed in a structure of the following form:
+.PP
+.in +4n
+.nf
+struct getbmap {
+	__s64   bmv_offset;
+	__s64   bmv_block;
+	__s64   bmv_length;
+	__s32   bmv_count;
+	__s32   bmv_entries;
+};
+.fi
+.in
+.PP
+The
+.B XFS_IOC_GETBMAPX
+ioctl uses a larger version of that structure:
+.PP
+.in +4n
+.nf
+struct getbmapx {
+	__s64   bmv_offset;
+	__s64   bmv_block;
+	__s64   bmv_length;
+	__s32   bmv_count;
+	__s32   bmv_entries;
+	__s32   bmv_iflags;
+	__s32   bmv_oflags;
+	__s32   bmv_unused1;
+	__s32   bmv_unused2;
+};
+.fi
+.in
+.PP
+All sizes and offsets in the structure are in units of 512 bytes.
+.PP
+The first structure in the array is a header and the remaining structures in
+the array contain block map information on return.
+The header controls iterative calls to the command and should be filled out as
+follows:
+.TP
+.B bmv_offset
+The file offset of the area of interest in the file.
+.TP
+.B bmv_length
+The length of the area of interest in the file.
+If this value is set to -1, the length of the interesting area is the rest of
+the file.
+.TP
+.B bmv_count
+The length of the array, including this header.
+.TP
+.B bmv_entries
+The number of entries actually filled in by the call.
+This does not need to be filled out before the call.
+.TP
+.B bmv_iflags
+For the
+.B XFS_IOC_GETBMAPX
+function, this is a combination of the following flags:
+.RS 0.4i
+.TP
+.B BMV_IF_ATTRFORK
+Return information about the extended attribute fork.
+.TP
+.B BMV_IF_PREALLOC
+Return information about unwritten pre-allocated segments.
+.TP
+.B BMV_IF_DELALLOC
+Return information about delayed allocation reservation segments.
+.TP
+.B BMV_IF_NO_HOLES
+Do not return information about holes.
+.RE
+.PD 1
+
+.PP
+On return from a call, the header is updated so that the command can be
+reused to obtain more information without re-initializing the structures.
+The remainder of the array will be filled out by the call as follows:
+
+.TP
+.B bmv_offset
+File offset of segment.
+.TP
+.B bmv_block
+Physical starting block of segment.
+If this is -1, then the segment is a hole.
+.TP
+.B bmv_length
+Length of segment.
+.TP
+.B bmv_oflags
+The
+.B XFS_IOC_GETBMAPX
+function will fill this field with a combination of the following flags:
+.RS 0.4i
+.TP
+.B BMV_OF_PREALLOC
+The segment is an unwritten pre-allocation.
+.TP
+.B BMV_OF_DELALLOC
+The segment is a delayed allocation reservation.
+.TP
+.B BMV_OF_LAST
+This segment is the last in the file.
+.TP
+.B BMV_OF_SHARED
+This segment shares blocks with other files.
+.RE
+.PD 1
+.PP
+The
+.B XFS_IOC_GETBMAPA
+command is identical to
+.B XFS_IOC_GETBMAP
+except that information about the attribute fork of the file is returned.
+.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 EFAULT
+The kernel was not able to copy into the userspace buffer.
+.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
+One of the arguments was not valid.
+.TP
+.B EIO
+An I/O error was encountered while performing the query.
+.TP
+.B ENOMEM
+There was insufficient memory to perform 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/man2/ioctl_xfs_goingdown.2 b/man/man2/ioctl_xfs_goingdown.2
new file mode 100644
index 00000000..e9a56f28
--- /dev/null
+++ b/man/man2/ioctl_xfs_goingdown.2
@@ -0,0 +1,61 @@ 
+.\" 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 2019-04-16 "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 the log, then shut down.
+.TP
+.B XFS_FSOP_GOING_FLAGS_LOGFLUSH
+Flush all pending transactions to the log, then shut down, leaving all dirty
+data unwritten.
+.TP
+.B XFS_FSOP_GOING_FLAGS_NOLOGFLUSH
+Shut down, leaving all dirty transactions and dirty data.
+
+.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 3b84ac2b..74c502cf 100644
--- a/man/man3/xfsctl.3
+++ b/man/man3/xfsctl.3
@@ -144,59 +144,17 @@  See
 .BR ioctl_xfs_fsgetxattr (2)
 for more information.
 
-.TP
-.B XFS_IOC_GETBMAP
-Get the block map for a segment of a file in an XFS file system.
-The final argument points to an arry of variables of type
-.BR "struct getbmap" .
-All sizes and offsets in the structure are in units of 512 bytes.
-The structure fields include:
-.B bmv_offset
-(file offset of segment),
-.B bmv_block
-(starting block of segment),
-.B bmv_length
-(length of segment),
-.B bmv_count
-(number of array entries, including the first), and
-.B bmv_entries
-(number of entries filled in).
-The first structure in the array is a header, and the remaining
-structures in the array contain block map information on return.
-The header controls iterative calls to the
+.PP
+.nf
 .B XFS_IOC_GETBMAP
-command.
-The caller fills in the
-.B bmv_offset
-and
-.B bmv_length
-fields of the header to indicate the area of interest in the file,
-and fills in the
-.B bmv_count
-field to indicate the length of the array.
-If the
-.B bmv_length
-value is set to \-1 then the length of the interesting area is the rest
-of the file.
-On return from a call, the header is updated so that the command can be
-reused to obtain more information, without re-initializing the structures.
-Also on return, the
-.B bmv_entries
-field of the header is set to the number of array entries actually filled in.
-The non-header structures will be filled in with
-.BR bmv_offset ,
-.BR bmv_block ,
-and
-.BR bmv_length .
-If a region of the file has no blocks (is a hole in the file) then the
-.B bmv_block
-field is set to \-1.
-
-.TP
 .B XFS_IOC_GETBMAPA
-Identical to
-.B XFS_IOC_GETBMAP
-except that information about the attribute fork of the file is returned.
+.fi
+.PD 0
+.TP
+.B XFS_IOC_GETBMAPX
+See
+.BR ioctl_getbmap (2)
+for more information.
 
 .PP
 .B XFS_IOC_RESVSP
@@ -407,6 +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