SBREAD(3) BSD Library Functions Manual SBREAD(3)NAME
sbread, sbwrite — read and write superblocks of a UFS file system
sbread(struct uufsd *disk);
sbwrite(struct uufsd *disk, int all);
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.
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.
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 ALSObread(3), bwrite(3), libufs(3)HISTORY
These functions first appeared as part of libufs(3) in FreeBSD 5.0.
Juli Mallett ⟨jmallett@FreeBSD.org⟩
BSD June 4, 2003 BSD