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NetBSD/sys/nfs/nfs_bio.c
fvdl 26a975b107 Move the EOF check after getting a block out of the if() that determines 
whether we get it off the wire. An nfsiod might have been busy with
it, and finished while we were waiting for it in nfs_getcacheblk, so
we need to check for EOF again no matter what.
1997-11-23 13:52:24 +00:00

1131 lines
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/* $NetBSD: nfs_bio.c,v 1.40 1997/11/23 13:52:24 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 <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>
#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;
#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);
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_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
*/
(void)vnode_pager_uncache(vp);
/*
* 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;
vnode_pager_setsize(vp, 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, 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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