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new queue structure
[unix-history] / usr / src / sys / nfs / nfs_bio.c
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* %sccs.include.redist.c%
*
* @(#)nfs_bio.c 8.4 (Berkeley) %G%
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/trace.h>
#include <sys/mount.h>
#include <sys/kernel.h>
#include <vm/vm.h>
#include <nfs/nfsnode.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsv2.h>
#include <nfs/nfs.h>
#include <nfs/nfsmount.h>
#include <nfs/nqnfs.h>
struct buf *incore(), *nfs_getcacheblk();
extern struct proc *nfs_iodwant[NFS_MAXASYNCDAEMON];
extern int nfs_numasync;
/*
* Vnode op for read using bio
* Any similarity to readip() is purely coincidental
*/
nfs_bioread(vp, uio, ioflag, cred)
register struct vnode *vp;
register struct uio *uio;
int ioflag;
struct ucred *cred;
{
register struct nfsnode *np = VTONFS(vp);
register int biosize, diff;
struct buf *bp, *rabp;
struct vattr vattr;
struct proc *p;
struct nfsmount *nmp;
daddr_t lbn, bn, rabn;
caddr_t baddr;
int got_buf, len, nra, error = 0, n, on, not_readin;
#ifdef lint
ioflag = ioflag;
#endif /* lint */
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("nfs_read mode");
#endif
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0 && vp->v_type != VDIR)
return (EINVAL);
nmp = VFSTONFS(vp->v_mount);
biosize = nmp->nm_rsize;
p = uio->uio_procp;
/*
* For nfs, cache consistency can only be maintained approximately.
* Although RFC1094 does not specify the criteria, the following is
* believed to be compatible with the reference port.
* For nqnfs, full cache consistency is maintained within the loop.
* For nfs:
* If the file's modify time on the server has changed since the
* last read rpc or you have written to the file,
* you may have lost data cache consistency with the
* server, so flush all of the file's data out of the cache.
* Then force a getattr rpc to ensure that you have up to date
* attributes.
* The mount flag NFSMNT_MYWRITE says "Assume that my writes are
* the ones changing the modify time.
* NB: This implies that cache data can be read when up to
* NFS_ATTRTIMEO seconds out of date. If you find that you need current
* attributes this could be forced by setting n_attrstamp to 0 before
* the VOP_GETATTR() call.
*/
if ((nmp->nm_flag & NFSMNT_NQNFS) == 0 && vp->v_type != VLNK) {
if (np->n_flag & NMODIFIED) {
if ((nmp->nm_flag & NFSMNT_MYWRITE) == 0 ||
vp->v_type != VREG) {
if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1))
return (error);
}
np->n_attrstamp = 0;
np->n_direofoffset = 0;
if (error = VOP_GETATTR(vp, &vattr, cred, p))
return (error);
np->n_mtime = vattr.va_mtime.ts_sec;
} else {
if (error = VOP_GETATTR(vp, &vattr, cred, p))
return (error);
if (np->n_mtime != vattr.va_mtime.ts_sec) {
np->n_direofoffset = 0;
if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1))
return (error);
np->n_mtime = vattr.va_mtime.ts_sec;
}
}
}
do {
/*
* Get a valid lease. If cached data is stale, flush it.
*/
if (nmp->nm_flag & NFSMNT_NQNFS) {
if (NQNFS_CKINVALID(vp, np, NQL_READ)) {
do {
error = nqnfs_getlease(vp, NQL_READ, cred, p);
} while (error == NQNFS_EXPIRED);
if (error)
return (error);
if (np->n_lrev != np->n_brev ||
(np->n_flag & NQNFSNONCACHE) ||
((np->n_flag & NMODIFIED) && vp->v_type == VDIR)) {
if (vp->v_type == VDIR) {
np->n_direofoffset = 0;
cache_purge(vp);
}
if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1))
return (error);
np->n_brev = np->n_lrev;
}
} else if (vp->v_type == VDIR && (np->n_flag & NMODIFIED)) {
np->n_direofoffset = 0;
cache_purge(vp);
if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1))
return (error);
}
}
if (np->n_flag & NQNFSNONCACHE) {
switch (vp->v_type) {
case VREG:
error = nfs_readrpc(vp, uio, cred);
break;
case VLNK:
error = nfs_readlinkrpc(vp, uio, cred);
break;
case VDIR:
error = nfs_readdirrpc(vp, uio, cred);
break;
};
return (error);
}
baddr = (caddr_t)0;
switch (vp->v_type) {
case VREG:
nfsstats.biocache_reads++;
lbn = uio->uio_offset / biosize;
on = uio->uio_offset & (biosize-1);
bn = lbn * (biosize / DEV_BSIZE);
not_readin = 1;
/*
* Start the read ahead(s), as required.
*/
if (nfs_numasync > 0 && nmp->nm_readahead > 0 &&
lbn == vp->v_lastr + 1) {
for (nra = 0; nra < nmp->nm_readahead &&
(lbn + 1 + nra) * biosize < np->n_size; nra++) {
rabn = (lbn + 1 + nra) * (biosize / DEV_BSIZE);
if (!incore(vp, rabn)) {
rabp = nfs_getcacheblk(vp, rabn, biosize, p);
if (!rabp)
return (EINTR);
if ((rabp->b_flags & (B_DELWRI | B_DONE)) == 0) {
rabp->b_flags |= (B_READ | B_ASYNC);
if (nfs_asyncio(rabp, cred)) {
rabp->b_flags |= B_INVAL;
brelse(rabp);
}
}
}
}
}
/*
* If the block is in the cache and has the required data
* in a valid region, just copy it out.
* Otherwise, get the block and write back/read in,
* as required.
*/
if ((bp = incore(vp, bn)) &&
(bp->b_flags & (B_BUSY | B_WRITEINPROG)) ==
(B_BUSY | B_WRITEINPROG))
got_buf = 0;
else {
again:
bp = nfs_getcacheblk(vp, bn, biosize, p);
if (!bp)
return (EINTR);
got_buf = 1;
if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) {
bp->b_flags |= B_READ;
not_readin = 0;
if (error = nfs_doio(bp, cred, p)) {
brelse(bp);
return (error);
}
}
}
n = min((unsigned)(biosize - on), uio->uio_resid);
diff = np->n_size - uio->uio_offset;
if (diff < n)
n = diff;
if (not_readin && n > 0) {
if (on < bp->b_validoff || (on + n) > bp->b_validend) {
if (!got_buf) {
bp = nfs_getcacheblk(vp, bn, biosize, p);
if (!bp)
return (EINTR);
got_buf = 1;
}
bp->b_flags |= B_INVAL;
if (bp->b_dirtyend > 0) {
if ((bp->b_flags & B_DELWRI) == 0)
panic("nfsbioread");
if (VOP_BWRITE(bp) == EINTR)
return (EINTR);
} else
brelse(bp);
goto again;
}
}
vp->v_lastr = lbn;
diff = (on >= bp->b_validend) ? 0 : (bp->b_validend - on);
if (diff < n)
n = diff;
break;
case VLNK:
nfsstats.biocache_readlinks++;
bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, p);
if (!bp)
return (EINTR);
if ((bp->b_flags & B_DONE) == 0) {
bp->b_flags |= B_READ;
if (error = nfs_doio(bp, cred, p)) {
brelse(bp);
return (error);
}
}
n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
got_buf = 1;
on = 0;
break;
case VDIR:
nfsstats.biocache_readdirs++;
bn = (daddr_t)uio->uio_offset;
bp = nfs_getcacheblk(vp, bn, NFS_DIRBLKSIZ, p);
if (!bp)
return (EINTR);
if ((bp->b_flags & B_DONE) == 0) {
bp->b_flags |= B_READ;
if (error = nfs_doio(bp, cred, p)) {
brelse(bp);
return (error);
}
}
/*
* If not eof and read aheads are enabled, start one.
* (You need the current block first, so that you have the
* directory offset cookie of the next block.
*/
rabn = bp->b_blkno;
if (nfs_numasync > 0 && nmp->nm_readahead > 0 &&
rabn != 0 && rabn != np->n_direofoffset &&
!incore(vp, rabn)) {
rabp = nfs_getcacheblk(vp, rabn, NFS_DIRBLKSIZ, p);
if (rabp) {
if ((rabp->b_flags & (B_DONE | B_DELWRI)) == 0) {
rabp->b_flags |= (B_READ | B_ASYNC);
if (nfs_asyncio(rabp, cred)) {
rabp->b_flags |= B_INVAL;
brelse(rabp);
}
}
}
}
on = 0;
n = min(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid);
got_buf = 1;
break;
};
if (n > 0) {
if (!baddr)
baddr = bp->b_data;
error = uiomove(baddr + on, (int)n, uio);
}
switch (vp->v_type) {
case VREG:
if (n + on == biosize || uio->uio_offset == np->n_size)
bp->b_flags |= B_AGE;
break;
case VLNK:
n = 0;
break;
case VDIR:
uio->uio_offset = bp->b_blkno;
break;
};
if (got_buf)
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n > 0);
return (error);
}
/*
* Vnode op for write using bio
*/
nfs_write(ap)
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
register int biosize;
register struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
register struct vnode *vp = ap->a_vp;
struct nfsnode *np = VTONFS(vp);
register struct ucred *cred = ap->a_cred;
int ioflag = ap->a_ioflag;
struct buf *bp;
struct vattr vattr;
struct nfsmount *nmp;
daddr_t lbn, bn;
int n, on, error = 0;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_WRITE)
panic("nfs_write mode");
if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
panic("nfs_write proc");
#endif
if (vp->v_type != VREG)
return (EIO);
if (np->n_flag & NWRITEERR) {
np->n_flag &= ~NWRITEERR;
return (np->n_error);
}
if (ioflag & (IO_APPEND | IO_SYNC)) {
if (np->n_flag & NMODIFIED) {
np->n_attrstamp = 0;
if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1))
return (error);
}
if (ioflag & IO_APPEND) {
np->n_attrstamp = 0;
if (error = VOP_GETATTR(vp, &vattr, cred, p))
return (error);
uio->uio_offset = np->n_size;
}
}
nmp = VFSTONFS(vp->v_mount);
if (uio->uio_offset < 0)
return (EINVAL);
if (uio->uio_resid == 0)
return (0);
/*
* Maybe this should be above the vnode op call, but so long as
* file servers have no limits, i don't think it matters
*/
if (p && uio->uio_offset + uio->uio_resid >
p->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
psignal(p, SIGXFSZ);
return (EFBIG);
}
/*
* I use nm_rsize, not nm_wsize so that all buffer cache blocks
* will be the same size within a filesystem. nfs_writerpc will
* still use nm_wsize when sizing the rpc's.
*/
biosize = nmp->nm_rsize;
do {
/*
* Check for a valid write lease.
* If non-cachable, just do the rpc
*/
if ((nmp->nm_flag & NFSMNT_NQNFS) &&
NQNFS_CKINVALID(vp, np, NQL_WRITE)) {
do {
error = nqnfs_getlease(vp, NQL_WRITE, cred, p);
} while (error == NQNFS_EXPIRED);
if (error)
return (error);
if (np->n_lrev != np->n_brev ||
(np->n_flag & NQNFSNONCACHE)) {
if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1))
return (error);
np->n_brev = np->n_lrev;
}
}
if (np->n_flag & NQNFSNONCACHE)
return (nfs_writerpc(vp, uio, cred, ioflag));
nfsstats.biocache_writes++;
lbn = uio->uio_offset / biosize;
on = uio->uio_offset & (biosize-1);
n = min((unsigned)(biosize - on), uio->uio_resid);
bn = lbn * (biosize / DEV_BSIZE);
again:
bp = nfs_getcacheblk(vp, bn, biosize, p);
if (!bp)
return (EINTR);
if (bp->b_wcred == NOCRED) {
crhold(cred);
bp->b_wcred = cred;
}
np->n_flag |= NMODIFIED;
if (uio->uio_offset + n > np->n_size) {
np->n_size = uio->uio_offset + n;
vnode_pager_setsize(vp, (u_long)np->n_size);
}
/*
* If the new write will leave a contiguous dirty
* area, just update the b_dirtyoff and b_dirtyend,
* otherwise force a write rpc of the old dirty area.
*/
if (bp->b_dirtyend > 0 &&
(on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
bp->b_proc = p;
if (VOP_BWRITE(bp) == EINTR)
return (EINTR);
goto again;
}
/*
* Check for valid write lease and get one as required.
* In case getblk() and/or bwrite() delayed us.
*/
if ((nmp->nm_flag & NFSMNT_NQNFS) &&
NQNFS_CKINVALID(vp, np, NQL_WRITE)) {
do {
error = nqnfs_getlease(vp, NQL_WRITE, cred, p);
} while (error == NQNFS_EXPIRED);
if (error) {
brelse(bp);
return (error);
}
if (np->n_lrev != np->n_brev ||
(np->n_flag & NQNFSNONCACHE)) {
brelse(bp);
if (error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1))
return (error);
np->n_brev = np->n_lrev;
goto again;
}
}
if (error = uiomove((char *)bp->b_data + on, n, uio)) {
bp->b_flags |= B_ERROR;
brelse(bp);
return (error);
}
if (bp->b_dirtyend > 0) {
bp->b_dirtyoff = min(on, bp->b_dirtyoff);
bp->b_dirtyend = max((on + n), bp->b_dirtyend);
} else {
bp->b_dirtyoff = on;
bp->b_dirtyend = on + n;
}
#ifndef notdef
if (bp->b_validend == 0 || bp->b_validend < bp->b_dirtyoff ||
bp->b_validoff > bp->b_dirtyend) {
bp->b_validoff = bp->b_dirtyoff;
bp->b_validend = bp->b_dirtyend;
} else {
bp->b_validoff = min(bp->b_validoff, bp->b_dirtyoff);
bp->b_validend = max(bp->b_validend, bp->b_dirtyend);
}
#else
bp->b_validoff = bp->b_dirtyoff;
bp->b_validend = bp->b_dirtyend;
#endif
if (ioflag & IO_APPEND)
bp->b_flags |= B_APPENDWRITE;
/*
* If the lease is non-cachable or IO_SYNC do bwrite().
*/
if ((np->n_flag & NQNFSNONCACHE) || (ioflag & IO_SYNC)) {
bp->b_proc = p;
if (error = VOP_BWRITE(bp))
return (error);
} else if ((n + on) == biosize &&
(nmp->nm_flag & NFSMNT_NQNFS) == 0) {
bp->b_proc = (struct proc *)0;
bawrite(bp);
} else
bdwrite(bp);
} while (uio->uio_resid > 0 && n > 0);
return (0);
}
/*
* Get an nfs cache block.
* Allocate a new one if the block isn't currently in the cache
* and return the block marked busy. If the calling process is
* interrupted by a signal for an interruptible mount point, return
* NULL.
*/
struct buf *
nfs_getcacheblk(vp, bn, size, p)
struct vnode *vp;
daddr_t bn;
int size;
struct proc *p;
{
register struct buf *bp;
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
if (nmp->nm_flag & NFSMNT_INT) {
bp = getblk(vp, bn, size, PCATCH, 0);
while (bp == (struct buf *)0) {
if (nfs_sigintr(nmp, (struct nfsreq *)0, p))
return ((struct buf *)0);
bp = getblk(vp, bn, size, 0, 2 * hz);
}
} else
bp = getblk(vp, bn, size, 0, 0);
return (bp);
}
/*
* Flush and invalidate all dirty buffers. If another process is already
* doing the flush, just wait for completion.
*/
nfs_vinvalbuf(vp, flags, cred, p, intrflg)
struct vnode *vp;
int flags;
struct ucred *cred;
struct proc *p;
int intrflg;
{
register struct nfsnode *np = VTONFS(vp);
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
int error = 0, slpflag, slptimeo;
if ((nmp->nm_flag & NFSMNT_INT) == 0)
intrflg = 0;
if (intrflg) {
slpflag = PCATCH;
slptimeo = 2 * hz;
} else {
slpflag = 0;
slptimeo = 0;
}
/*
* First wait for any other process doing a flush to complete.
*/
while (np->n_flag & NFLUSHINPROG) {
np->n_flag |= NFLUSHWANT;
error = tsleep((caddr_t)&np->n_flag, PRIBIO + 2, "nfsvinval",
slptimeo);
if (error && intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p))
return (EINTR);
}
/*
* Now, flush as required.
*/
np->n_flag |= NFLUSHINPROG;
error = vinvalbuf(vp, flags, cred, p, slpflag, 0);
while (error) {
if (intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p)) {
np->n_flag &= ~NFLUSHINPROG;
if (np->n_flag & NFLUSHWANT) {
np->n_flag &= ~NFLUSHWANT;
wakeup((caddr_t)&np->n_flag);
}
return (EINTR);
}
error = vinvalbuf(vp, flags, cred, p, 0, slptimeo);
}
np->n_flag &= ~(NMODIFIED | NFLUSHINPROG);
if (np->n_flag & NFLUSHWANT) {
np->n_flag &= ~NFLUSHWANT;
wakeup((caddr_t)&np->n_flag);
}
return (0);
}
/*
* Initiate asynchronous I/O. Return an error if no nfsiods are available.
* This is mainly to avoid queueing async I/O requests when the nfsiods
* are all hung on a dead server.
*/
nfs_asyncio(bp, cred)
register struct buf *bp;
struct ucred *cred;
{
register int i;
if (nfs_numasync == 0)
return (EIO);
for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
if (nfs_iodwant[i]) {
if (bp->b_flags & B_READ) {
if (bp->b_rcred == NOCRED && cred != NOCRED) {
crhold(cred);
bp->b_rcred = cred;
}
} else {
if (bp->b_wcred == NOCRED && cred != NOCRED) {
crhold(cred);
bp->b_wcred = cred;
}
}
TAILQ_INSERT_TAIL(&nfs_bufq, bp, b_freelist);
nfs_iodwant[i] = (struct proc *)0;
wakeup((caddr_t)&nfs_iodwant[i]);
return (0);
}
return (EIO);
}
/*
* Do an I/O operation to/from a cache block. This may be called
* synchronously or from an nfsiod.
*/
int
nfs_doio(bp, cr, p)
register struct buf *bp;
struct cred *cr;
struct proc *p;
{
register struct uio *uiop;
register struct vnode *vp;
struct nfsnode *np;
struct nfsmount *nmp;
int error, diff, len;
struct uio uio;
struct iovec io;
vp = bp->b_vp;
np = VTONFS(vp);
nmp = VFSTONFS(vp->v_mount);
uiop = &uio;
uiop->uio_iov = &io;
uiop->uio_iovcnt = 1;
uiop->uio_segflg = UIO_SYSSPACE;
uiop->uio_procp = p;
/*
* Historically, paging was done with physio, but no more.
*/
if (bp->b_flags & B_PHYS)
panic("doio phys");
if (bp->b_flags & B_READ) {
io.iov_len = uiop->uio_resid = bp->b_bcount;
io.iov_base = bp->b_data;
uiop->uio_rw = UIO_READ;
switch (vp->v_type) {
case VREG:
uiop->uio_offset = bp->b_blkno * DEV_BSIZE;
nfsstats.read_bios++;
error = nfs_readrpc(vp, uiop, cr);
if (!error) {
bp->b_validoff = 0;
if (uiop->uio_resid) {
/*
* If len > 0, there is a hole in the file and
* no writes after the hole have been pushed to
* the server yet.
* Just zero fill the rest of the valid area.
*/
diff = bp->b_bcount - uiop->uio_resid;
len = np->n_size - (bp->b_blkno * DEV_BSIZE
+ diff);
if (len > 0) {
len = min(len, uiop->uio_resid);
bzero((char *)bp->b_data + diff, len);
bp->b_validend = diff + len;
} else
bp->b_validend = diff;
} else
bp->b_validend = bp->b_bcount;
}
if (p && (vp->v_flag & VTEXT) &&
(((nmp->nm_flag & NFSMNT_NQNFS) &&
np->n_lrev != np->n_brev) ||
(!(nmp->nm_flag & NFSMNT_NQNFS) &&
np->n_mtime != np->n_vattr.va_mtime.ts_sec))) {
uprintf("Process killed due to text file modification\n");
psignal(p, SIGKILL);
p->p_flag |= P_NOSWAP;
}
break;
case VLNK:
uiop->uio_offset = 0;
nfsstats.readlink_bios++;
error = nfs_readlinkrpc(vp, uiop, cr);
break;
case VDIR:
uiop->uio_offset = bp->b_lblkno;
nfsstats.readdir_bios++;
if (VFSTONFS(vp->v_mount)->nm_flag & NFSMNT_NQNFS)
error = nfs_readdirlookrpc(vp, uiop, cr);
else
error = nfs_readdirrpc(vp, uiop, cr);
/*
* Save offset cookie in b_blkno.
*/
bp->b_blkno = uiop->uio_offset;
break;
};
if (error) {
bp->b_flags |= B_ERROR;
bp->b_error = error;
}
} else {
io.iov_len = uiop->uio_resid = bp->b_dirtyend
- bp->b_dirtyoff;
uiop->uio_offset = (bp->b_blkno * DEV_BSIZE)
+ bp->b_dirtyoff;
io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
uiop->uio_rw = UIO_WRITE;
nfsstats.write_bios++;
if (bp->b_flags & B_APPENDWRITE)
error = nfs_writerpc(vp, uiop, cr, IO_APPEND);
else
error = nfs_writerpc(vp, uiop, cr, 0);
bp->b_flags &= ~(B_WRITEINPROG | B_APPENDWRITE);
/*
* For an interrupted write, the buffer is still valid and the
* write hasn't been pushed to the server yet, so we can't set
* B_ERROR and report the interruption by setting B_EINTR. For
* the B_ASYNC case, B_EINTR is not relevant, so the rpc attempt
* is essentially a noop.
*/
if (error == EINTR) {
bp->b_flags &= ~B_INVAL;
bp->b_flags |= B_DELWRI;
/*
* Since for the B_ASYNC case, nfs_bwrite() has reassigned the
* buffer to the clean list, we have to reassign it back to the
* dirty one. Ugh.
*/
if (bp->b_flags & B_ASYNC)
reassignbuf(bp, vp);
else
bp->b_flags |= B_EINTR;
} else {
if (error) {
bp->b_flags |= B_ERROR;
bp->b_error = np->n_error = error;
np->n_flag |= NWRITEERR;
}
bp->b_dirtyoff = bp->b_dirtyend = 0;
}
}
bp->b_resid = uiop->uio_resid;
biodone(bp);
return (error);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.