minix/lib/libc/sys/lfs_markv.2

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.\" $NetBSD: lfs_markv.2,v 1.11 2008/04/30 13:10:51 martin Exp $
.\"
.\" Copyright (c) 2000 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Konrad Schroder.
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.Dd May 23, 2000
.Dt LFS_MARKV 2
.Os
.Sh NAME
.Nm lfs_markv
.Nd rewrite disk blocks to new disk locations
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/types.h
.In ufs/lfs/lfs.h
.Ft int
.Fn lfs_markv "fsid_t *fsidp" "BLOCK_INFO *blkiov" "int blkcnt"
.Sh DESCRIPTION
.Fn lfs_markv
rewrites the blocks specified in
.Fa blkiov
to new disk locations, for the purposes of grouping them next to one
another, or to move them out of a segment to clean it.
All fields of the BLOCK_INFO structure must be filled in, except for
.Fa bi_segcreate .
If
.Fa bi_daddr
is not the correct current address for logical block
.Fa bi_lbn
of the file with inode number
.Fa bi_inode ,
or if the file's version number does not match
.Fa bi_version ,
the block will not be written to disk, but no error will be returned.
.Pp
The
.Fa fsidp
argument contains the id of the filesystem to which the inodes and
blocks belong.
The
.Fa bi_bp
field contains
.Fa bi_size
bytes of data to be written into the appropriate block.
If
.Fa bi_lbn
is specified as LFS_UNUSED_LBN, the inode itself will be rewritten.
.Pp
The
.Fa blkiov
argument is an array of BLOCK_INFO structures (see below).
The
.Fa blkcnt
argument determines the size of the
.Fa blkiov
array.
.Bd -literal
typedef struct block_info {
ino_t bi_inode; /* inode # */
ufs_daddr_t bi_lbn; /* logical block w/in file */
ufs_daddr_t bi_daddr; /* disk address of block */
time_t bi_segcreate; /* origin segment create time */
int bi_version; /* file version number */
void *bi_bp; /* data buffer */
int bi_size; /* size of the block (if fragment) */
} BLOCK_INFO;
.Ed
.Sh RETURN VALUES
.Fn lfs_markv
returns 0 on success, or \-1 on error.
.Sh ERRORS
An error return from
.Fn lfs_markv
indicates:
.Bl -tag -width Er
.It Bq Er EFAULT
.Fa fsidp
points outside the process's allocated address space.
.It Bq Er EINVAL
.Fa *fsidp
does not specify a valid filesystem.
.It Bq Er EBUSY
One or more of the inodes whose blocks were to be written was locked,
and its blocks were not rewritten.
.El
.Sh SEE ALSO
.Xr lfs_segclean 2 ,
.Xr lfs_segwait 2 ,
.Xr lfs_cleanerd 8
.Sh HISTORY
The
.Fn lfs_markv
function call appeared in
.Bx 4.4 .
.Sh BUGS
The functionality of
.Fn lfs_markv
does not really belong in user space.
Among other things it could be used to work around the
SF_IMMUTABLE
and
SF_APPEND
file flags (see
.Xr chflags 2 ) .