/*
* Mark I/O complete on a buffer.
*
* If a callback has been requested, e.g. the pageout
* daemon, do so. Otherwise, awaken waiting processes.
*
* [ Leffler, et al., says on p.247:
* "This routine wakes up the blocked process, frees the buffer
* for an asynchronous write, or, for a request by the pagedaemon
* process, invokes a procedure specified in the buffer structure" ]
*
* In real life, the pagedaemon (or other system processes) wants
* to do async stuff to, and doesn't want the buffer brelse()'d.
* (for swap pager, that puts swap buffers on the free lists (!!!),
* for the vn device, that puts malloc'd buffers on the free lists!)
*
* Must be called at splbio().
*/
void
biodone(struct buf *bp)
{
splassert(IPL_BIO);
if (ISSET(bp->b_flags, B_DONE))
panic("biodone already");
SET(bp->b_flags, B_DONE); /* note that it's done */
if (LIST_FIRST(&bp->b_dep) != NULL)
buf_complete(bp);
if (!ISSET(bp->b_flags, B_READ)) {
CLR(bp->b_flags, B_WRITEINPROG);
vwakeup(bp->b_vp);
}
if (ISSET(bp->b_flags, B_CALL)) { /* if necessary, call out */
CLR(bp->b_flags, B_CALL); /* but note callout done */
(*bp->b_iodone)(bp);
} else {
if (ISSET(bp->b_flags, B_ASYNC)) {/* if async, release it */
brelse(bp);
} else { /* or just wakeup the buffer */
CLR(bp->b_flags, B_WANTED);
wakeup(bp);
}
}
}
/*
* Finish up operations on a buffer, calling an optional
* function (if requested), and releasing the buffer if
* marked asynchronous. Then mark this buffer done so that
* others biowait()'ing for it will notice when they are
* woken up from sleep().
*/
int
biodone(register struct buf *bp)
{
int x;
x = splbio();
if (bp->b_flags & B_CALL) (*bp->b_iodone)(bp);
bp->b_flags &= ~B_CALL;
if ((bp->b_flags & (B_READ|B_DIRTY)) == B_DIRTY) {
bp->b_flags &= ~B_DIRTY;
vwakeup(bp);
}
if (bp->b_flags & B_ASYNC)
brelse(bp);
bp->b_flags &= ~B_ASYNC;
bp->b_flags |= B_DONE;
wakeup(bp);
splx(x);
}
