xref: /freebsd/lib/libufs/sbread.3 (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
1.\" Author:	Juli Mallett <jmallett@FreeBSD.org>
2.\" Date:	June 04, 2003
3.\" Description:
4.\" 	Manual page for libufs functions:
5.\"		sbread(3)
6.\"		sbwrite(3)
7.\"
8.\" This file is in the public domain.
9.\"
10.\" $FreeBSD$
11.\"
12.Dd June 4, 2003
13.Dt SBREAD 3
14.Os
15.Sh NAME
16.Nm sbread , sbwrite
17.Nd read and write superblocks of a UFS filesystem
18.Sh LIBRARY
19.Lb libufs
20.Sh SYNOPSIS
21.In sys/param.h
22.In sys/mount.h
23.In ufs/ufs/ufsmount.h
24.In ufs/ufs/dinode.h
25.In ufs/ffs/fs.h
26.In libufs.h
27.Ft int
28.Fn sbread "struct uufsd *disk"
29.Ft int
30.Fn sbwrite "struct uufsd *disk" "int all"
31.Sh DESCRIPTION
32The
33.Fn sbread
34and
35.Fn sbwrite
36functions provide superblock reads and writes for
37.Xr libufs 3
38consumers.
39The
40.Fn sbread
41and
42.Fn sbwrite
43functions operate on the superblock field,
44.Fa d_sb ,
45associated with a given userland UFS disk structure.
46Additionally, the
47.Fn sbwrite
48function will write to all superblock locations if the
49.Fa all
50value is non-zero.
51.Pp
52The
53.Fn sbread
54and
55.Fn sbwrite
56functions return 0 on success or -1 on error.
57.Sh ERRORS
58The function
59.Fn sbread
60may fail and set
61.Va errno
62for any of the errors specified for the library function
63.Xr bread 3 .
64Additionally, it may follow the
65.Xr libufs 3
66error methodologies in situations where no usable superblock could be
67found.
68.Pp
69The function
70.Fn sbwrite
71may fail and set
72.Va errno
73for any of the errors specified for the library function
74.Xr bwrite 3 .
75.Sh SEE ALSO
76.Xr bread 3 ,
77.Xr bwrite 3 ,
78.Xr libufs 3
79.Sh HISTORY
80These functions first appeared as part of
81.Xr libufs 3
82in
83.Fx 5.0 .
84.Sh AUTHORS
85.An Juli Mallett Aq jmallett@FreeBSD.org
86