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NetBSD/sys/nfs/nfs_bio.c

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/* $NetBSD: nfs_bio.c,v 1.43 1998/06/21 22:18:16 fvdl Exp $ */
/*
* 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 8.9 (Berkeley) 3/30/95
*/
#include "opt_uvm.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.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 <sys/namei.h>
#include <sys/dirent.h>
#include <vm/vm.h>
#if defined(UVM)
#include <uvm/uvm_extern.h>
#endif
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsmount.h>
#include <nfs/nqnfs.h>
#include <nfs/nfsnode.h>
#include <nfs/nfs_var.h>
extern int nfs_numasync;
extern struct nfsstats nfsstats;
/*
* Vnode op for read using bio
* Any similarity to readip() is purely coincidental
*/
int
nfs_bioread(vp, uio, ioflag, cred, cflag)
register struct vnode *vp;
register struct uio *uio;
int ioflag, cflag;
struct ucred *cred;
{
register struct nfsnode *np = VTONFS(vp);
register int biosize, diff;
struct buf *bp = NULL, *rabp;
struct vattr vattr;
struct proc *p;
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
struct nfsdircache *ndp = NULL, *nndp = NULL;
daddr_t lbn, bn, rabn;
caddr_t baddr, ep, edp;
int got_buf = 0, nra, error = 0, n = 0, on = 0, not_readin, en, enn;
int enough = 0;
struct dirent *dp, *pdp;
off_t curoff = 0, offdiff;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("nfs_read mode");
#endif
if (uio->uio_resid == 0)
return (0);
if (vp->v_type != VDIR && uio->uio_offset < 0)
return (EINVAL);
p = uio->uio_procp;
if ((nmp->nm_flag & NFSMNT_NFSV3) &&
!(nmp->nm_iflag & NFSMNT_GOTFSINFO))
(void)nfs_fsinfo(nmp, vp, cred, p);
if (vp->v_type != VDIR &&
(uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
return (EFBIG);
biosize = nmp->nm_rsize;
/*
* 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.
* 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 (vp->v_type != VREG) {
if (vp->v_type != VDIR)
panic("nfs: bioread, not dir");
nfs_invaldircache(vp, 0);
np->n_direofoffset = 0;
error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
if (error)
return (error);
}
np->n_attrstamp = 0;
error = VOP_GETATTR(vp, &vattr, cred, p);
if (error)
return (error);
np->n_mtime = vattr.va_mtime.tv_sec;
} else {
error = VOP_GETATTR(vp, &vattr, cred, p);
if (error)
return (error);
if (np->n_mtime != vattr.va_mtime.tv_sec) {
if (vp->v_type == VDIR) {
nfs_invaldircache(vp, 0);
np->n_direofoffset = 0;
}
error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
if (error)
return (error);
np->n_mtime = vattr.va_mtime.tv_sec;
}
}
}
do {
/*
* Get a valid lease. If cached data is stale, flush it.
*/
if (nmp->nm_flag & NFSMNT_NQNFS) {
if (NQNFS_CKINVALID(vp, np, ND_READ)) {
do {
error = nqnfs_getlease(vp, ND_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) {
nfs_invaldircache(vp, 0);
np->n_direofoffset = 0;
}
error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
if (error)
return (error);
np->n_brev = np->n_lrev;
}
} else if (vp->v_type == VDIR && (np->n_flag & NMODIFIED)) {
nfs_invaldircache(vp, 0);
error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
np->n_direofoffset = 0;
if (error)
return (error);
}
}
/*
* Don't cache symlinks.
*/
if (np->n_flag & NQNFSNONCACHE
|| ((vp->v_flag & VROOT) && vp->v_type == VLNK)) {
switch (vp->v_type) {
case VREG:
return (nfs_readrpc(vp, uio, cred));
case VLNK:
return (nfs_readlinkrpc(vp, uio, cred));
case VDIR:
break;
default:
printf(" NQNFSNONCACHE: type %x unexpected\n",
vp->v_type);
};
}
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 - 1 == vp->v_lastr) {
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);
}
} else
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;
error = nfs_doio(bp, cred, p);
if (error) {
brelse(bp);
return (error);
}
}
}
n = min((unsigned)(biosize - on), uio->uio_resid);
offdiff = np->n_size - uio->uio_offset;
if (offdiff < (off_t)n)
n = (int)offdiff;
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_INVAFTERWRITE;
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;
error = nfs_doio(bp, cred, p);
if (error) {
brelse(bp);
return (error);
}
}
n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
got_buf = 1;
on = 0;
break;
case VDIR:
diragain:
nfsstats.biocache_readdirs++;
ndp = nfs_searchdircache(vp, uio->uio_offset,
(nmp->nm_flag & NFSMNT_XLATECOOKIE), 0);
if (!ndp) {
/*
* We've been handed a cookie that is not
* in the cache. If we're not translating
* 32 <-> 64, it may be a value that was
* flushed out of the cache because it grew
* too big. Let the server judge if it's
* valid or not. In the translation case,
* we have no way of validating this value,
* so punt.
*/
if (nmp->nm_flag & NFSMNT_XLATECOOKIE)
return (EINVAL);
ndp = nfs_enterdircache(vp, uio->uio_offset,
uio->uio_offset, 0, 0);
}
if (uio->uio_offset != 0 &&
ndp->dc_cookie == np->n_direofoffset) {
nfsstats.direofcache_hits++;
return (0);
}
bp = nfs_getcacheblk(vp, ndp->dc_blkno, NFS_DIRBLKSIZ, p);
if (!bp)
return (EINTR);
if ((bp->b_flags & B_DONE) == 0) {
bp->b_flags |= B_READ;
bp->b_dcookie = ndp->dc_blkcookie;
error = nfs_doio(bp, cred, p);
if (error) {
/*
* Yuck! The directory has been modified on the
* server. Punt and let the userland code
* deal with it.
*/
brelse(bp);
if (error == NFSERR_BAD_COOKIE) {
nfs_invaldircache(vp, 0);
nfs_vinvalbuf(vp, 0, cred, p, 1);
error = EINVAL;
}
return (error);
}
}
/*
* Just return if we hit EOF right away with this
* block. Always check here, because direofoffset
* may have been set by an nfsiod since the last
* check.
*/
if (np->n_direofoffset != 0 &&
ndp->dc_blkcookie == np->n_direofoffset) {
brelse(bp);
return (0);
}
/*
* Find the entry we were looking for in the block.
*/
en = ndp->dc_entry;
pdp = dp = (struct dirent *)bp->b_data;
edp = bp->b_data + bp->b_validend;
enn = 0;
while (enn < en && (caddr_t)dp < edp) {
pdp = dp;
dp = (struct dirent *)((caddr_t)dp + dp->d_reclen);
enn++;
}
/*
* If the entry number was bigger than the number of
* entries in the block, or the cookie of the previous
* entry doesn't match, the directory cache is
* stale. Flush it and try again (i.e. go to
* the server).
*/
if ((caddr_t)dp >= edp || (caddr_t)dp + dp->d_reclen > edp ||
(en > 0 && NFS_GETCOOKIE(pdp) != ndp->dc_cookie)) {
#ifdef DEBUG
printf("invalid cache: %p %p %p off %lx %lx\n",
pdp, dp, edp,
(unsigned long)uio->uio_offset,
(unsigned long)NFS_GETCOOKIE(pdp));
#endif
brelse(bp);
nfs_invaldircache(vp, 0);
nfs_vinvalbuf(vp, 0, cred, p, 0);
goto diragain;
}
on = (caddr_t)dp - bp->b_data;
/*
* Cache all entries that may be exported to the
* user, as they may be thrown back at us. The
* NFSBIO_CACHECOOKIES flag indicates that all
* entries are being 'exported', so cache them all.
*/
if (en == 0 && pdp == dp) {
dp = (struct dirent *)
((caddr_t)dp + dp->d_reclen);
enn++;
}
if (uio->uio_resid < (bp->b_validend - on)) {
n = uio->uio_resid;
enough = 1;
} else
n = bp->b_validend - on;
ep = bp->b_data + on + n;
/*
* Find last complete entry to copy, caching entries
* (if requested) as we go.
*/
while ((caddr_t)dp < ep && (caddr_t)dp + dp->d_reclen <= ep) {
if (cflag & NFSBIO_CACHECOOKIES) {
nndp = nfs_enterdircache(vp, NFS_GETCOOKIE(pdp),
ndp->dc_blkcookie, enn, bp->b_lblkno);
if (nmp->nm_flag & NFSMNT_XLATECOOKIE) {
NFS_STASHCOOKIE32(pdp,
nndp->dc_cookie32);
}
}
pdp = dp;
dp = (struct dirent *)((caddr_t)dp + dp->d_reclen);
enn++;
}
/*
* If the last requested entry was not the last in the
* buffer (happens if NFS_DIRFRAGSIZ < NFS_DIRBLKSIZ),
* cache the cookie of the last requested one, and
* set of the offset to it.
*/
if ((on + n) < bp->b_validend) {
curoff = NFS_GETCOOKIE(pdp);
nndp = nfs_enterdircache(vp, curoff, ndp->dc_blkcookie,
enn, bp->b_lblkno);
if (nmp->nm_flag & NFSMNT_XLATECOOKIE) {
NFS_STASHCOOKIE32(pdp, nndp->dc_cookie32);
curoff = nndp->dc_cookie32;
}
} else
curoff = bp->b_dcookie;
/*
* Always cache the entry for the next block,
* so that readaheads can use it.
*/
nndp = nfs_enterdircache(vp, bp->b_dcookie, bp->b_dcookie, 0,0);
if (nmp->nm_flag & NFSMNT_XLATECOOKIE) {
if (curoff == bp->b_dcookie) {
NFS_STASHCOOKIE32(pdp, nndp->dc_cookie32);
curoff = nndp->dc_cookie32;
}
}
n = ((caddr_t)pdp + pdp->d_reclen) - (bp->b_data + on);
/*
* 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.)
*/
if (nfs_numasync > 0 && nmp->nm_readahead > 0 &&
np->n_direofoffset == 0 && !(np->n_flag & NQNFSNONCACHE)) {
rabp = nfs_getcacheblk(vp, nndp->dc_blkno,
NFS_DIRBLKSIZ, p);
if (rabp) {
if ((rabp->b_flags & (B_DONE | B_DELWRI)) == 0) {
rabp->b_dcookie = nndp->dc_cookie;
rabp->b_flags |= (B_READ | B_ASYNC);
if (nfs_asyncio(rabp, cred)) {
rabp->b_flags |= B_INVAL;
brelse(rabp);
}
} else
brelse(rabp);
}
}
got_buf = 1;
break;
default:
printf(" nfsbioread: type %x unexpected\n",vp->v_type);
break;
};
if (n > 0) {
if (!baddr)
baddr = bp->b_data;
error = uiomove(baddr + on, (int)n, uio);
}
switch (vp->v_type) {
case VREG:
break;
case VLNK:
n = 0;
break;
case VDIR:
if (np->n_flag & NQNFSNONCACHE)
bp->b_flags |= B_INVAL;
uio->uio_offset = curoff;
if (enough)
n = 0;
break;
default:
printf(" nfsbioread: type %x unexpected\n",vp->v_type);
}
if (got_buf)
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n > 0);
return (error);
}
/*
* Vnode op for write using bio
*/
int
nfs_write(v)
void *v;
{
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap = v;
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 = VFSTONFS(vp->v_mount);
daddr_t lbn, bn;
int n, on, error = 0, iomode, must_commit;
#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 ((nmp->nm_flag & NFSMNT_NFSV3) &&
!(nmp->nm_iflag & NFSMNT_GOTFSINFO))
(void)nfs_fsinfo(nmp, vp, cred, p);
if (ioflag & (IO_APPEND | IO_SYNC)) {
if (np->n_flag & NMODIFIED) {
np->n_attrstamp = 0;
error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
if (error)
return (error);
}
if (ioflag & IO_APPEND) {
np->n_attrstamp = 0;
error = VOP_GETATTR(vp, &vattr, cred, p);
if (error)
return (error);
uio->uio_offset = np->n_size;
}
}
if (uio->uio_offset < 0)
return (EINVAL);
if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
return (EFBIG);
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 {
/*
* XXX make sure we aren't cached in the VM page cache
*/
#if defined(UVM)
(void)uvm_vnp_uncache(vp);
#else
(void)vnode_pager_uncache(vp);
#endif
/*
* Check for a valid write lease.
*/
if ((nmp->nm_flag & NFSMNT_NQNFS) &&
NQNFS_CKINVALID(vp, np, ND_WRITE)) {
do {
error = nqnfs_getlease(vp, ND_WRITE, cred, p);
} while (error == NQNFS_EXPIRED);
if (error)
return (error);
if (np->n_lrev != np->n_brev ||
(np->n_flag & NQNFSNONCACHE)) {
error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
if (error)
return (error);
np->n_brev = np->n_lrev;
}
}
if ((np->n_flag & NQNFSNONCACHE) && uio->uio_iovcnt == 1) {
iomode = NFSV3WRITE_FILESYNC;
error = nfs_writerpc(vp, uio, cred, &iomode, &must_commit);
if (must_commit)
nfs_clearcommit(vp->v_mount);
return (error);
}
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;
#if defined(UVM)
uvm_vnp_setsize(vp, np->n_size);
#else
vnode_pager_setsize(vp, np->n_size);
#endif
}
/*
* 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, ND_WRITE)) {
do {
error = nqnfs_getlease(vp, ND_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);
error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
if (error)
return (error);
np->n_brev = np->n_lrev;
goto again;
}
}
error = uiomove((char *)bp->b_data + on, n, uio);
if (error) {
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;
}
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);
}
/*
* Since this block is being modified, it must be written
* again and not just committed.
*/
bp->b_flags &= ~B_NEEDCOMMIT;
/*
* If the lease is non-cachable or IO_SYNC do bwrite().
*/
if ((np->n_flag & NQNFSNONCACHE) || (ioflag & IO_SYNC)) {
bp->b_proc = p;
error = VOP_BWRITE(bp);
if (error)
return (error);
if (np->n_flag & NQNFSNONCACHE) {
error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
if (error)
return (error);
}
} else if ((n + on) == biosize &&
(nmp->nm_flag & NFSMNT_NQNFS) == 0) {
bp->b_proc = (struct proc *)0;
bp->b_flags |= B_ASYNC;
(void)nfs_writebp(bp, 0);
} 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.
*/
int
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.
*/
int
nfs_asyncio(bp, cred)
register struct buf *bp;
struct ucred *cred;
{
register int i;
register struct nfsmount *nmp;
int gotiod, slpflag = 0, slptimeo = 0, error;
if (nfs_numasync == 0)
return (EIO);
nmp = VFSTONFS(bp->b_vp->v_mount);
again:
if (nmp->nm_flag & NFSMNT_INT)
slpflag = PCATCH;
gotiod = FALSE;
/*
* Find a free iod to process this request.
*/
for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
if (nfs_iodwant[i]) {
/*
* Found one, so wake it up and tell it which
* mount to process.
*/
nfs_iodwant[i] = (struct proc *)0;
nfs_iodmount[i] = nmp;
nmp->nm_bufqiods++;
wakeup((caddr_t)&nfs_iodwant[i]);
gotiod = TRUE;
break;
}
/*
* If none are free, we may already have an iod working on this mount
* point. If so, it will process our request.
*/
if (!gotiod && nmp->nm_bufqiods > 0)
gotiod = TRUE;
/*
* If we have an iod which can process the request, then queue
* the buffer.
*/
if (gotiod) {
/*
* Ensure that the queue never grows too large.
*/
while (nmp->nm_bufqlen >= 2*nfs_numasync) {
nmp->nm_bufqwant = TRUE;
error = tsleep(&nmp->nm_bufq, slpflag | PRIBIO,
"nfsaio", slptimeo);
if (error) {
if (nfs_sigintr(nmp, NULL, bp->b_proc))
return (EINTR);
if (slpflag == PCATCH) {
slpflag = 0;
slptimeo = 2 * hz;
}
}
/*
* We might have lost our iod while sleeping,
* so check and loop if nescessary.
*/
if (nmp->nm_bufqiods == 0)
goto again;
}
if (bp->b_flags & B_READ) {
if (bp->b_rcred == NOCRED && cred != NOCRED) {
crhold(cred);
bp->b_rcred = cred;
}
} else {
bp->b_flags |= B_WRITEINPROG;
if (bp->b_wcred == NOCRED && cred != NOCRED) {
crhold(cred);
bp->b_wcred = cred;
}
}
TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
nmp->nm_bufqlen++;
return (0);
}
/*
* All the iods are busy on other mounts, so return EIO to
* force the caller to process the i/o synchronously.
*/
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 ucred *cr;
struct proc *p;
{
register struct uio *uiop;
register struct vnode *vp;
struct nfsnode *np;
struct nfsmount *nmp;
int error = 0, diff, len, iomode, must_commit = 0;
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) {
/*
* ...though reading /dev/drum still gets us here.
*/
io.iov_len = uiop->uio_resid = bp->b_bcount;
/* mapping was done by vmapbuf() */
io.iov_base = bp->b_data;
uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
if (bp->b_flags & B_READ) {
uiop->uio_rw = UIO_READ;
nfsstats.read_physios++;
error = nfs_readrpc(vp, uiop, cr);
} else {
iomode = NFSV3WRITE_DATASYNC;
uiop->uio_rw = UIO_WRITE;
nfsstats.write_physios++;
error = nfs_writerpc(vp, uiop, cr, &iomode, &must_commit);
}
if (error) {
bp->b_flags |= B_ERROR;
bp->b_error = error;
}
} else 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 = ((off_t)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 - (((u_quad_t)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) &&
NQNFS_CKINVALID(vp, np, ND_READ) &&
np->n_lrev != np->n_brev) ||
(!(nmp->nm_flag & NFSMNT_NQNFS) &&
np->n_mtime != np->n_vattr->va_mtime.tv_sec))) {
uprintf("Process killed due to text file modification\n");
psignal(p, SIGKILL);
p->p_holdcnt++;
}
break;
case VLNK:
uiop->uio_offset = (off_t)0;
nfsstats.readlink_bios++;
error = nfs_readlinkrpc(vp, uiop, cr);
break;
case VDIR:
nfsstats.readdir_bios++;
uiop->uio_offset = bp->b_dcookie;
if (nmp->nm_flag & NFSMNT_RDIRPLUS) {
error = nfs_readdirplusrpc(vp, uiop, cr);
if (error == NFSERR_NOTSUPP)
nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
}
if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
error = nfs_readdirrpc(vp, uiop, cr);
if (!error) {
bp->b_dcookie = uiop->uio_offset;
bp->b_validoff = 0;
bp->b_validend = bp->b_bcount - uiop->uio_resid;
}
break;
default:
printf("nfs_doio: type %x unexpected\n",vp->v_type);
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 = ((off_t)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_ASYNC | B_NEEDCOMMIT | B_NOCACHE)) == B_ASYNC)
iomode = NFSV3WRITE_UNSTABLE;
else
iomode = NFSV3WRITE_FILESYNC;
bp->b_flags |= B_WRITEINPROG;
#ifdef fvdl_debug
printf("nfs_doio(%x): bp %x doff %d dend %d\n",
vp, bp, bp->b_dirtyoff, bp->b_dirtyend);
#endif
error = nfs_writerpc(vp, uiop, cr, &iomode, &must_commit);
if (!error && iomode == NFSV3WRITE_UNSTABLE)
bp->b_flags |= B_NEEDCOMMIT;
else
bp->b_flags &= ~B_NEEDCOMMIT;
bp->b_flags &= ~B_WRITEINPROG;
/*
* 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.
* For the case of a V3 write rpc not being committed to stable
* storage, the block is still dirty and requires either a commit
* rpc or another write rpc with iomode == NFSV3WRITE_FILESYNC
* before the block is reused. This is indicated by setting the
* B_DELWRI and B_NEEDCOMMIT flags.
*/
if (error == EINTR || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
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 if (error)
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;
if (must_commit)
nfs_clearcommit(vp->v_mount);
biodone(bp);
return (error);
}
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