-/* vfs_bio.c 4.23 81/07/25 */
+/* vfs_bio.c 4.32 82/06/01 */
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/vm.h"
#include "../h/trace.h"
-/*
- * The following several routines allocate and free
- * buffers with various side effects. In general the
- * arguments to an allocate routine are a device and
- * a block number, and the value is a pointer to
- * to the buffer header; the buffer is marked "busy"
- * so that no one else can touch it. If the block was
- * already in core, no I/O need be done; if it is
- * already busy, the process waits until it becomes free.
- * The following routines allocate a buffer:
- * getblk
- * bread
- * breada
- * baddr (if it is incore)
- * Eventually the buffer must be released, possibly with the
- * side effect of writing it out, by using one of
- * bwrite
- * bdwrite
- * bawrite
- * brelse
- */
-
-struct buf bfreelist[BQUEUES];
-struct buf bswlist, *bclnlist;
-
-#define BUFHSZ 63
-struct bufhd bufhash[BUFHSZ];
-#define BUFHASH(dev, dblkno) \
- ((struct buf *)&bufhash[((int)(dev)+(int)(dblkno)) % BUFHSZ])
-
-/*
- * Initialize hash links for buffers.
- */
-bhinit()
-{
- register int i;
- register struct bufhd *bp;
-
- for (bp = bufhash, i = 0; i < BUFHSZ; i++, bp++)
- bp->b_forw = bp->b_back = (struct buf *)bp;
-}
-
-/* #define DISKMON 1 */
-
-#ifdef DISKMON
-struct {
- int nbuf;
- long nread;
- long nreada;
- long ncache;
- long nwrite;
- long bufcount[64];
-} io_info;
-#endif
-
-/*
- * Swap IO headers -
- * They contain the necessary information for the swap I/O.
- * At any given time, a swap header can be in three
- * different lists. When free it is in the free list,
- * when allocated and the I/O queued, it is on the swap
- * device list, and finally, if the operation was a dirty
- * page push, when the I/O completes, it is inserted
- * in a list of cleaned pages to be processed by the pageout daemon.
- */
-struct buf *swbuf;
-short *swsize; /* CAN WE JUST USE B_BCOUNT? */
-int *swpf;
-
-
-#ifndef UNFAST
-#define notavail(bp) \
-{ \
- int s = spl6(); \
- (bp)->av_back->av_forw = (bp)->av_forw; \
- (bp)->av_forw->av_back = (bp)->av_back; \
- (bp)->b_flags |= B_BUSY; \
- splx(s); \
-}
-#endif
-
/*
* Read in (if necessary) the block and return a buffer pointer.
*/
struct buf *
-bread(dev, blkno)
-dev_t dev;
-daddr_t blkno;
+bread(dev, blkno, size)
+ dev_t dev;
+ daddr_t blkno;
+ int size;
{
register struct buf *bp;
- bp = getblk(dev, blkno);
+ bp = getblk(dev, blkno, size);
if (bp->b_flags&B_DONE) {
-#ifdef TRACE
trace(TR_BREADHIT, dev, blkno);
-#endif
-#ifdef DISKMON
- io_info.ncache++;
-#endif
return(bp);
}
bp->b_flags |= B_READ;
- bp->b_bcount = BSIZE;
(*bdevsw[major(dev)].d_strategy)(bp);
-#ifdef TRACE
trace(TR_BREADMISS, dev, blkno);
-#endif
-#ifdef DISKMON
- io_info.nread++;
-#endif
u.u_vm.vm_inblk++; /* pay for read */
- iowait(bp);
+ biowait(bp);
return(bp);
}
* read-ahead block (which is not allocated to the caller)
*/
struct buf *
-breada(dev, blkno, rablkno)
-dev_t dev;
-daddr_t blkno, rablkno;
+breada(dev, blkno, rablkno, size)
+ dev_t dev;
+ daddr_t blkno, rablkno;
+ int size;
{
register struct buf *bp, *rabp;
bp = NULL;
+ /*
+ * If the block isn't in core, then allocate
+ * a buffer and initiate i/o (getblk checks
+ * for a cache hit).
+ */
if (!incore(dev, blkno)) {
- bp = getblk(dev, blkno);
+ bp = getblk(dev, blkno, size);
if ((bp->b_flags&B_DONE) == 0) {
bp->b_flags |= B_READ;
- bp->b_bcount = BSIZE;
(*bdevsw[major(dev)].d_strategy)(bp);
-#ifdef TRACE
trace(TR_BREADMISS, dev, blkno);
-#endif
-#ifdef DISKMON
- io_info.nread++;
-#endif
u.u_vm.vm_inblk++; /* pay for read */
- }
-#ifdef TRACE
- else
+ } else
trace(TR_BREADHIT, dev, blkno);
-#endif
}
+
+ /*
+ * If there's a read-ahead block, start i/o
+ * on it also (as above).
+ */
if (rablkno && !incore(dev, rablkno)) {
- rabp = getblk(dev, rablkno);
+ rabp = getblk(dev, rablkno, size);
if (rabp->b_flags & B_DONE) {
brelse(rabp);
-#ifdef TRACE
trace(TR_BREADHITRA, dev, blkno);
-#endif
} else {
rabp->b_flags |= B_READ|B_ASYNC;
- rabp->b_bcount = BSIZE;
(*bdevsw[major(dev)].d_strategy)(rabp);
-#ifdef TRACE
trace(TR_BREADMISSRA, dev, rablock);
-#endif
-#ifdef DISKMON
- io_info.nreada++;
-#endif
u.u_vm.vm_inblk++; /* pay in advance */
}
}
+
+ /*
+ * If we get here with bp NULL, then the block
+ * must've been in core and bread will find it for us.
+ */
if(bp == NULL)
- return(bread(dev, blkno));
- iowait(bp);
+ return(bread(dev, blkno, size));
+ biowait(bp);
return(bp);
}
* Then release the buffer.
*/
bwrite(bp)
-register struct buf *bp;
+ register struct buf *bp;
{
register flag;
flag = bp->b_flags;
bp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI | B_AGE);
- bp->b_bcount = BSIZE;
-#ifdef DISKMON
- io_info.nwrite++;
-#endif
if ((flag&B_DELWRI) == 0)
u.u_vm.vm_oublk++; /* noone paid yet */
-#ifdef TRACE
trace(TR_BWRITE, bp->b_dev, bp->b_blkno);
-#endif
(*bdevsw[major(bp->b_dev)].d_strategy)(bp);
+
+ /*
+ * If the write was synchronous, then await i/o completion.
+ * If the write was "delayed", then we put the buffer on
+ * the q of blocks awaiting i/o completion status.
+ * Otherwise, the i/o must be finished and we check for
+ * an error.
+ */
if ((flag&B_ASYNC) == 0) {
- iowait(bp);
+ biowait(bp);
brelse(bp);
} else if (flag & B_DELWRI)
bp->b_flags |= B_AGE;
* in the same order as requested.
*/
bdwrite(bp)
-register struct buf *bp;
+ register struct buf *bp;
{
register int flags;
* Release the buffer, start I/O on it, but don't wait for completion.
*/
bawrite(bp)
-register struct buf *bp;
+ register struct buf *bp;
{
bp->b_flags |= B_ASYNC;
}
/*
- * release the buffer, with no I/O implied.
+ * Release the buffer, with no I/O implied.
*/
brelse(bp)
-register struct buf *bp;
+ register struct buf *bp;
{
register struct buf *flist;
register s;
+ /*
+ * If someone's waiting for the buffer, or
+ * is waiting for a buffer wake 'em up.
+ */
if (bp->b_flags&B_WANTED)
wakeup((caddr_t)bp);
if (bfreelist[0].b_flags&B_WANTED) {
bp->b_flags &= ~B_ERROR; /* try again later */
else
bp->b_dev = NODEV; /* no assoc */
+
+ /*
+ * Stick the buffer back on a free list.
+ */
s = spl6();
if (bp->b_flags & (B_ERROR|B_INVAL)) {
/* block has no info ... put at front of most free list */
flist = &bfreelist[BQUEUES-1];
- flist->av_forw->av_back = bp;
- bp->av_forw = flist->av_forw;
- flist->av_forw = bp;
- bp->av_back = flist;
+ binsheadfree(bp, flist);
} else {
if (bp->b_flags & B_LOCKED)
flist = &bfreelist[BQ_LOCKED];
flist = &bfreelist[BQ_AGE];
else
flist = &bfreelist[BQ_LRU];
- flist->av_back->av_forw = bp;
- bp->av_back = flist->av_back;
- flist->av_back = bp;
- bp->av_forw = flist;
+ binstailfree(bp, flist);
}
bp->b_flags &= ~(B_WANTED|B_BUSY|B_ASYNC|B_AGE);
splx(s);
* (mainly to avoid getting hung up on a wait in breada)
*/
incore(dev, blkno)
-dev_t dev;
-daddr_t blkno;
+ dev_t dev;
+ daddr_t blkno;
{
register struct buf *bp;
register struct buf *dp;
- register int dblkno = fsbtodb(blkno);
- dp = BUFHASH(dev, dblkno);
+ dp = BUFHASH(dev, blkno);
for (bp = dp->b_forw; bp != dp; bp = bp->b_forw)
- if (bp->b_blkno == dblkno && bp->b_dev == dev &&
- !(bp->b_flags & B_INVAL))
+ if (bp->b_blkno == blkno && bp->b_dev == dev &&
+ (bp->b_flags & B_INVAL) == 0)
return (1);
return (0);
}
struct buf *
-baddr(dev, blkno)
-dev_t dev;
-daddr_t blkno;
+baddr(dev, blkno, size)
+ dev_t dev;
+ daddr_t blkno;
+ int size;
{
if (incore(dev, blkno))
- return (bread(dev, blkno));
+ return (bread(dev, blkno, size));
return (0);
}
* Assign a buffer for the given block. If the appropriate
* block is already associated, return it; otherwise search
* for the oldest non-busy buffer and reassign it.
+ *
+ * We use splx here because this routine may be called
+ * on the interrupt stack during a dump, and we don't
+ * want to lower the ipl back to 0.
*/
struct buf *
-getblk(dev, blkno)
-dev_t dev;
-daddr_t blkno;
+getblk(dev, blkno, size)
+ dev_t dev;
+ daddr_t blkno;
+ int size;
{
register struct buf *bp, *dp, *ep;
- register int dblkno = fsbtodb(blkno);
-#ifdef DISKMON
- register int i;
-#endif
+ int s;
if ((unsigned)blkno >= 1 << (sizeof(int)*NBBY-PGSHIFT))
blkno = 1 << ((sizeof(int)*NBBY-PGSHIFT) + 1);
- dblkno = fsbtodb(blkno);
- dp = BUFHASH(dev, dblkno);
- loop:
- (void) spl0();
+ /*
+ * Search the cache for the block. If we hit, but
+ * the buffer is in use for i/o, then we wait until
+ * the i/o has completed.
+ */
+ dp = BUFHASH(dev, blkno);
+loop:
for (bp = dp->b_forw; bp != dp; bp = bp->b_forw) {
- if (bp->b_blkno != dblkno || bp->b_dev != dev ||
+ if (bp->b_blkno != blkno || bp->b_dev != dev ||
bp->b_flags&B_INVAL)
continue;
- (void) spl6();
+ s = spl6();
if (bp->b_flags&B_BUSY) {
bp->b_flags |= B_WANTED;
sleep((caddr_t)bp, PRIBIO+1);
+ splx(s);
goto loop;
}
- (void) spl0();
-#ifdef DISKMON
- i = 0;
- dp = bp->av_forw;
- while ((dp->b_flags & B_HEAD) == 0) {
- i++;
- dp = dp->av_forw;
- }
- if (i<64)
- io_info.bufcount[i]++;
-#endif
+ splx(s);
notavail(bp);
+ brealloc(bp, size);
bp->b_flags |= B_CACHE;
return(bp);
}
if (major(dev) >= nblkdev)
panic("blkdev");
- (void) spl6();
+ /*
+ * Not found in the cache, select something from
+ * a free list. Preference is to LRU list, then AGE list.
+ */
+ s = spl6();
for (ep = &bfreelist[BQUEUES-1]; ep > bfreelist; ep--)
if (ep->av_forw != ep)
break;
if (ep == bfreelist) { /* no free blocks at all */
ep->b_flags |= B_WANTED;
sleep((caddr_t)ep, PRIBIO+1);
+ splx(s);
goto loop;
}
- (void) spl0();
+ splx(s);
bp = ep->av_forw;
notavail(bp);
if (bp->b_flags & B_DELWRI) {
bwrite(bp);
goto loop;
}
-#ifdef TRACE
trace(TR_BRELSE, bp->b_dev, bp->b_blkno);
-#endif
bp->b_flags = B_BUSY;
- bp->b_back->b_forw = bp->b_forw;
- bp->b_forw->b_back = bp->b_back;
- bp->b_forw = dp->b_forw;
- bp->b_back = dp;
- dp->b_forw->b_back = bp;
- dp->b_forw = bp;
+ bfree(bp);
+ bremhash(bp);
+ binshash(bp, dp);
bp->b_dev = dev;
- bp->b_blkno = dblkno;
+ bp->b_blkno = blkno;
+ brealloc(bp, size);
return(bp);
}
* not assigned to any particular device
*/
struct buf *
-geteblk()
+geteblk(size)
+ int size;
{
register struct buf *bp, *dp;
+ int s;
loop:
- (void) spl6();
+ s = spl6();
for (dp = &bfreelist[BQUEUES-1]; dp > bfreelist; dp--)
if (dp->av_forw != dp)
break;
sleep((caddr_t)dp, PRIBIO+1);
goto loop;
}
- (void) spl0();
+ splx(s);
bp = dp->av_forw;
notavail(bp);
if (bp->b_flags & B_DELWRI) {
bwrite(bp);
goto loop;
}
-#ifdef TRACE
trace(TR_BRELSE, bp->b_dev, bp->b_blkno);
-#endif
bp->b_flags = B_BUSY|B_INVAL;
- bp->b_back->b_forw = bp->b_forw;
- bp->b_forw->b_back = bp->b_back;
- bp->b_forw = dp->b_forw;
- bp->b_back = dp;
- dp->b_forw->b_back = bp;
- dp->b_forw = bp;
+ bfree(bp);
+ bremhash(bp);
+ binshash(bp, dp);
bp->b_dev = (dev_t)NODEV;
+ brealloc(bp, size);
return(bp);
}
/*
- * Wait for I/O completion on the buffer; return errors
- * to the user.
+ * Allocate space associated with a buffer.
*/
-iowait(bp)
-register struct buf *bp;
+brealloc(bp, size)
+ register struct buf *bp;
+ int size;
{
+ daddr_t start, last;
+ register struct buf *ep;
+ struct buf *dp;
+ int s;
- (void) spl6();
- while ((bp->b_flags&B_DONE)==0)
- sleep((caddr_t)bp, PRIBIO);
- (void) spl0();
- geterror(bp);
+ /*
+ * First need to make sure that all overlaping previous I/O
+ * is dispatched with.
+ */
+ if (size == bp->b_bcount)
+ return;
+ if (size < bp->b_bcount || bp->b_dev == NODEV)
+ goto allocit;
+
+ start = bp->b_blkno + (bp->b_bcount / DEV_BSIZE);
+ last = bp->b_blkno + (size / DEV_BSIZE) - 1;
+ if (bp->b_bcount == 0) {
+ start++;
+ if (start == last)
+ goto allocit;
+ }
+ dp = BUFHASH(bp->b_dev, bp->b_blkno);
+loop:
+ for (ep = dp->b_forw; ep != dp; ep = ep->b_forw) {
+ if (ep->b_blkno < start || ep->b_blkno > last ||
+ ep->b_dev != bp->b_dev || ep->b_flags&B_INVAL)
+ continue;
+ s = spl6();
+ if (ep->b_flags&B_BUSY) {
+ ep->b_flags |= B_WANTED;
+ sleep((caddr_t)ep, PRIBIO+1);
+ (void) splx(s);
+ goto loop;
+ }
+ (void) splx(s);
+ /*
+ * What we would really like to do is kill this
+ * I/O since it is now useless. We cannot do that
+ * so we force it to complete, so that it cannot
+ * over-write our useful data later.
+ */
+ if (ep->b_flags & B_DELWRI) {
+ notavail(ep);
+ ep->b_flags |= B_ASYNC;
+ bwrite(ep);
+ goto loop;
+ }
+ }
+allocit:
+ /*
+ * Here the buffer is already available, so all we
+ * need to do is set the size. Someday a better memory
+ * management scheme will be implemented.
+ */
+ bp->b_bcount = size;
}
-#ifdef UNFAST
/*
- * Unlink a buffer from the available list and mark it busy.
- * (internal interface)
+ * Release space associated with a buffer.
*/
-notavail(bp)
-register struct buf *bp;
+bfree(bp)
+ struct buf *bp;
{
- register s;
+ /*
+ * Here the buffer does not change, so all we
+ * need to do is set the size. Someday a better memory
+ * management scheme will be implemented.
+ */
+ bp->b_bcount = 0;
+}
+
+/*
+ * Wait for I/O completion on the buffer; return errors
+ * to the user.
+ */
+biowait(bp)
+ register struct buf *bp;
+{
+ int s;
s = spl6();
- bp->av_back->av_forw = bp->av_forw;
- bp->av_forw->av_back = bp->av_back;
- bp->b_flags |= B_BUSY;
+ while ((bp->b_flags&B_DONE)==0)
+ sleep((caddr_t)bp, PRIBIO);
splx(s);
+ geterror(bp);
}
-#endif
/*
* Mark I/O complete on a buffer. If the header
* release it if I/O is asynchronous, and wake
* up anyone waiting for it.
*/
-iodone(bp)
-register struct buf *bp;
+biodone(bp)
+ register struct buf *bp;
{
register int s;
if (bp->b_flags & B_DONE)
- panic("dup iodone");
+ panic("dup biodone");
bp->b_flags |= B_DONE;
if (bp->b_flags & B_DIRTY) {
if (bp->b_flags & B_ERROR)
}
}
-/*
- * Zero the core associated with a buffer.
- */
-clrbuf(bp)
-struct buf *bp;
-{
- register *p;
- register c;
-
- p = bp->b_un.b_words;
- c = BSIZE/sizeof(int);
- do
- *p++ = 0;
- while (--c);
- bp->b_resid = 0;
-}
-
-/*
- * swap I/O -
- *
- * If the flag indicates a dirty page push initiated
- * by the pageout daemon, we map the page into the i th
- * virtual page of process 2 (the daemon itself) where i is
- * the index of the swap header that has been allocated.
- * We simply initialize the header and queue the I/O but
- * do not wait for completion. When the I/O completes,
- * iodone() will link the header to a list of cleaned
- * pages to be processed by the pageout daemon.
- */
-swap(p, dblkno, addr, nbytes, rdflg, flag, dev, pfcent)
- struct proc *p;
- swblk_t dblkno;
- caddr_t addr;
- int flag, nbytes;
- dev_t dev;
- unsigned pfcent;
-{
- register struct buf *bp;
- register int c;
- int p2dp;
- register struct pte *dpte, *vpte;
-
- (void) spl6();
- while (bswlist.av_forw == NULL) {
- bswlist.b_flags |= B_WANTED;
- sleep((caddr_t)&bswlist, PSWP+1);
- }
- bp = bswlist.av_forw;
- bswlist.av_forw = bp->av_forw;
- (void) spl0();
-
- bp->b_flags = B_BUSY | B_PHYS | rdflg | flag;
- if ((bp->b_flags & (B_DIRTY|B_PGIN)) == 0)
- if (rdflg == B_READ)
- sum.v_pswpin += btoc(nbytes);
- else
- sum.v_pswpout += btoc(nbytes);
- bp->b_proc = p;
- if (flag & B_DIRTY) {
- p2dp = ((bp - swbuf) * CLSIZE) * KLMAX;
- dpte = dptopte(&proc[2], p2dp);
- vpte = vtopte(p, btop(addr));
- for (c = 0; c < nbytes; c += NBPG) {
- if (vpte->pg_pfnum == 0 || vpte->pg_fod)
- panic("swap bad pte");
- *dpte++ = *vpte++;
- }
- bp->b_un.b_addr = (caddr_t)ctob(p2dp);
- } else
- bp->b_un.b_addr = addr;
- while (nbytes > 0) {
- c = imin(ctob(120), nbytes);
- bp->b_bcount = c;
- bp->b_blkno = dblkno;
- bp->b_dev = dev;
- if (flag & B_DIRTY) {
- swpf[bp - swbuf] = pfcent;
- swsize[bp - swbuf] = nbytes;
- }
-#ifdef TRACE
- trace(TR_SWAPIO, dev, bp->b_blkno);
-#endif
- (*bdevsw[major(dev)].d_strategy)(bp);
- if (flag & B_DIRTY) {
- if (c < nbytes)
- panic("big push");
- return;
- }
- (void) spl6();
- while((bp->b_flags&B_DONE)==0)
- sleep((caddr_t)bp, PSWP);
- (void) spl0();
- bp->b_un.b_addr += c;
- bp->b_flags &= ~B_DONE;
- if (bp->b_flags & B_ERROR) {
- if ((flag & (B_UAREA|B_PAGET)) || rdflg == B_WRITE)
- panic("hard IO err in swap");
- swkill(p, (char *)0);
- }
- nbytes -= c;
- dblkno += btoc(c);
- }
- (void) spl6();
- bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS|B_PAGET|B_UAREA|B_DIRTY);
- bp->av_forw = bswlist.av_forw;
- bswlist.av_forw = bp;
- if (bswlist.b_flags & B_WANTED) {
- bswlist.b_flags &= ~B_WANTED;
- wakeup((caddr_t)&bswlist);
- wakeup((caddr_t)&proc[2]);
- }
- (void) spl0();
-}
-
-/*
- * If rout == 0 then killed on swap error, else
- * rout is the name of the routine where we ran out of
- * swap space.
- */
-swkill(p, rout)
- struct proc *p;
- char *rout;
-{
- char *mesg;
-
- printf("pid %d: ", p->p_pid);
- if (rout)
- printf(mesg = "killed due to no swap space\n");
- else
- printf(mesg = "killed on swap error\n");
- uprintf("sorry, pid %d was %s", p->p_pid, mesg);
- /*
- * To be sure no looping (e.g. in vmsched trying to
- * swap out) mark process locked in core (as though
- * done by user) after killing it so noone will try
- * to swap it out.
- */
- psignal(p, SIGKILL);
- p->p_flag |= SULOCK;
-}
-
/*
* make sure all write-behind blocks
* on dev (or NODEV for all)
* are flushed out.
* (from umount and update)
+ * (and temporarily pagein)
*/
bflush(dev)
-dev_t dev;
+ dev_t dev;
{
register struct buf *bp;
register struct buf *flist;
+ int s;
loop:
- (void) spl6();
+ s = spl6();
for (flist = bfreelist; flist < &bfreelist[BQUEUES]; flist++)
for (bp = flist->av_forw; bp != flist; bp = bp->av_forw) {
- if (bp->b_flags&B_DELWRI && (dev == NODEV||dev==bp->b_dev)) {
+ if ((bp->b_flags & B_DELWRI) == 0)
+ continue;
+ if (dev == NODEV || dev == bp->b_dev) {
bp->b_flags |= B_ASYNC;
notavail(bp);
bwrite(bp);
goto loop;
}
}
- (void) spl0();
-}
-
-/*
- * Raw I/O. The arguments are
- * The strategy routine for the device
- * A buffer, which will always be a special buffer
- * header owned exclusively by the device for this purpose
- * The device number
- * Read/write flag
- * Essentially all the work is computing physical addresses and
- * validating them.
- * If the user has the proper access privilidges, the process is
- * marked 'delayed unlock' and the pages involved in the I/O are
- * faulted and locked. After the completion of the I/O, the above pages
- * are unlocked.
- */
-physio(strat, bp, dev, rw, mincnt)
-int (*strat)();
-register struct buf *bp;
-unsigned (*mincnt)();
-{
- register int c;
- char *a;
-
- if (useracc(u.u_base,u.u_count,rw==B_READ?B_WRITE:B_READ) == NULL) {
- u.u_error = EFAULT;
- return;
- }
- (void) spl6();
- while (bp->b_flags&B_BUSY) {
- bp->b_flags |= B_WANTED;
- sleep((caddr_t)bp, PRIBIO+1);
- }
- bp->b_error = 0;
- bp->b_proc = u.u_procp;
- bp->b_un.b_addr = u.u_base;
- while (u.u_count != 0) {
- bp->b_flags = B_BUSY | B_PHYS | rw;
- bp->b_dev = dev;
- bp->b_blkno = u.u_offset >> PGSHIFT;
- bp->b_bcount = u.u_count;
- (*mincnt)(bp);
- c = bp->b_bcount;
- u.u_procp->p_flag |= SPHYSIO;
- vslock(a = bp->b_un.b_addr, c);
- (*strat)(bp);
- (void) spl6();
- while ((bp->b_flags&B_DONE) == 0)
- sleep((caddr_t)bp, PRIBIO);
- vsunlock(a, c, rw);
- u.u_procp->p_flag &= ~SPHYSIO;
- if (bp->b_flags&B_WANTED)
- wakeup((caddr_t)bp);
- (void) spl0();
- bp->b_un.b_addr += c;
- u.u_count -= c;
- u.u_offset += c;
- if (bp->b_flags&B_ERROR)
- break;
- }
- bp->b_flags &= ~(B_BUSY|B_WANTED|B_PHYS);
- u.u_count = bp->b_resid;
- geterror(bp);
-}
-
-/*ARGSUSED*/
-unsigned
-minphys(bp)
-struct buf *bp;
-{
-
- if (bp->b_bcount > 60 * 1024)
- bp->b_bcount = 60 * 1024;
+ splx(s);
}
/*
* don't yet return specific errors.
*/
geterror(bp)
-register struct buf *bp;
+ register struct buf *bp;
{
if (bp->b_flags&B_ERROR)
* correctness. ... kre
*/
binval(dev)
-dev_t dev;
+ dev_t dev;
{
register struct buf *bp;
register struct bufhd *hp;