The
bread ();
and
bwrite ();
functions provide a block read and write API for
libufs(3)
consumers.
They operate on a userland UFS disk structure, and perform the read
and write at a given block address, which uses the current
d_bsize
value of the structure.
RETURN VALUES
The
bread ();
and
bwrite ();
functions return the amount read or written, or -1 in case of any error,
including short read.
ERRORS
The function
bread ();
may fail and set
errno
for any of the errors specified for the library functions
ufs_disk_write3
or
pread(2).
Additionally, it may follow the
libufs(3)
error methodologies in situations where the amount of data read
is not equal to the amount requested, or in case of device error.
The function
bwrite ();
may fail and set
errno
for any of the errors specified for the library function
pwrite(2).
Additionally, it may follow the
libufs(3)
error methodologies in situations where the amount of data written
is not equal to the amount requested, or in case of a device error.