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sbwrite(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 operate 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 speci-
     fied 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 spec-
     ified 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>

FreeBSD 5.4			 June 4, 2003			   FreeBSD 5.4

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