SBREAD(3)						   BSD Library Functions Manual 						 SBREAD(3)

NAME

     sbread, sbwrite -- read and write superblocks of a UFS file system

LIBRARY

     UFS File System Access Library (libufs, -lufs)

SYNOPSIS

     #include <sys/param.h>
     #include <sys/mount.h>
     #include <ufs/ufs/ufsmount.h>
     #include <ufs/ufs/dinode.h>
     #include <ufs/ffs/fs.h>
     #include <libufs.h>

     int
     sbread(struct uufsd *disk);

     int
     sbwrite(struct uufsd *disk, int all);

DESCRIPTION

     The sbread() and sbwrite() functions provide superblock reads and writes for libufs(3) consumers.	The sbread() and sbwrite() functions oper-
     ate on the superblock field, d_sb, associated with a given userland UFS disk structure.  Additionally, the sbwrite() function will write to
     all superblock locations if the all value is non-zero.

RETURN VALUES

     The sbread() and sbwrite() functions return the value 0 if successful; otherwise the value -1 is returned and the global variable errno is
     set to indicate the error.

ERRORS

     The function sbread() may fail and set errno for any of the errors specified for the library function bread(3).  Additionally, it may follow
     the libufs(3) error methodologies in situations where no usable superblock could be found.

     The function sbwrite() may fail and set errno for any of the errors specified for the library function bwrite(3).

SEE ALSO

     bread(3), bwrite(3), libufs(3)

HISTORY

     These functions first appeared as part of libufs(3) in FreeBSD 5.0.

AUTHORS

     Juli Mallett <jmallett@FreeBSD.org>

BSD
								   June 4, 2003 							       BSD