From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Create a separate manual page for the BMAP ioctls so we can document how
they work.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
man/man2/ioctl_xfs_getbmap.2 | 165 ++++++++++++++++++++++++++++++++++++++++++
man/man3/xfsctl.3 | 61 +++-------------
2 files changed, 175 insertions(+), 51 deletions(-)
create mode 100644 man/man2/ioctl_xfs_getbmap.2
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/man3/xfsctl.3 b/man/man3/xfsctl.3
index 25e51417..e0986afb 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
@@ -428,6 +386,7 @@ as they are not of general use to applications.
.BR ioctl_xfs_fsinumbers (2),
.BR ioctl_xfs_fscounts (2),
.BR ioctl_xfs_getresblks (2),
+.BR ioctl_xfs_getbmap (2),
.BR fstatfs (2),
.BR statfs (2),
.BR xfs (5),
