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-rw-r--r--sys/nfsclient/nfs_bio.c799
1 files changed, 799 insertions, 0 deletions
diff --git a/sys/nfsclient/nfs_bio.c b/sys/nfsclient/nfs_bio.c
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--- /dev/null
+++ b/sys/nfsclient/nfs_bio.c
@@ -0,0 +1,799 @@
+/*
+ * 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.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * @(#)nfs_bio.c 8.5 (Berkeley) 1/4/94
+ */
+
+#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, 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);
+}
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