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/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 --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