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NetBSD/sys/nfs/nfs_bio.c
chs b4224d4d38 fix locking in nfs_getpages().
2001-12-31 07:16:47 +00:00

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/* $NetBSD: nfs_bio.c,v 1.73 2001/12/31 07:16:47 chs 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: nfs_bio.c,v 1.73 2001/12/31 07:16:47 chs Exp $");
#include "opt_nfs.h"
#include "opt_ddb.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/mount.h>
#include <sys/kernel.h>
#include <sys/namei.h>
#include <sys/dirent.h>
#include <sys/malloc.h>
#include <uvm/uvm_extern.h>
#include <uvm/uvm.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)
struct vnode *vp;
struct uio *uio;
int ioflag, cflag;
struct ucred *cred;
{
struct nfsnode *np = VTONFS(vp);
struct buf *bp = NULL, *rabp;
struct vattr vattr;
struct proc *p;
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
struct nfsdircache *ndp = NULL, *nndp = NULL;
caddr_t baddr, ep, edp;
int got_buf = 0, error = 0, n = 0, on = 0, 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;
#ifndef NFS_V2_ONLY
if ((nmp->nm_flag & NFSMNT_NFSV3) &&
!(nmp->nm_iflag & NFSMNT_GOTFSINFO))
(void)nfs_fsinfo(nmp, vp, cred, p);
#endif
if (vp->v_type != VDIR &&
(uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
return (EFBIG);
/*
* 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;
}
}
}
/*
* update the cached read creds for this node.
*/
if (np->n_rcred) {
crfree(np->n_rcred);
}
np->n_rcred = cred;
crhold(cred);
do {
#ifndef NFS_V2_ONLY
/*
* 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);
}
}
#endif
/*
* 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));
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++;
error = 0;
if (uio->uio_offset >= np->n_size) {
break;
}
while (uio->uio_resid > 0) {
void *win;
vsize_t bytelen = MIN(np->n_size - uio->uio_offset,
uio->uio_resid);
if (bytelen == 0)
break;
win = ubc_alloc(&vp->v_uobj, uio->uio_offset,
&bytelen, UBC_READ);
error = uiomove(win, bytelen, uio);
ubc_release(win, 0);
if (error) {
break;
}
}
n = 0;
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, 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, 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_bcount - bp->b_resid;
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_bcount - bp->b_resid - on)) {
n = uio->uio_resid;
enough = 1;
} else
n = bp->b_bcount - bp->b_resid - 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_bcount - bp->b_resid) {
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)) {
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;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
struct vnode *vp = ap->a_vp;
struct nfsnode *np = VTONFS(vp);
struct ucred *cred = ap->a_cred;
int ioflag = ap->a_ioflag;
struct vattr vattr;
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
void *win;
voff_t oldoff, origoff;
vsize_t bytelen;
int 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);
}
#ifndef NFS_V2_ONLY
if ((nmp->nm_flag & NFSMNT_NFSV3) &&
!(nmp->nm_iflag & NFSMNT_GOTFSINFO))
(void)nfs_fsinfo(nmp, vp, cred, p);
#endif
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);
}
/*
* update the cached write creds for this node.
*/
if (np->n_wcred) {
crfree(np->n_wcred);
}
np->n_wcred = cred;
crhold(cred);
if ((np->n_flag & NQNFSNONCACHE) && uio->uio_iovcnt == 1) {
iomode = NFSV3WRITE_FILESYNC;
error = nfs_writerpc(vp, uio, &iomode, &must_commit);
if (must_commit)
nfs_clearcommit(vp->v_mount);
return (error);
}
origoff = uio->uio_offset;
do {
oldoff = uio->uio_offset;
bytelen = uio->uio_resid;
#ifndef NFS_V2_ONLY
/*
* 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;
}
}
#endif
nfsstats.biocache_writes++;
np->n_flag |= NMODIFIED;
if (np->n_size < uio->uio_offset + bytelen) {
np->n_size = uio->uio_offset + bytelen;
}
if ((uio->uio_offset & PAGE_MASK) == 0 &&
((uio->uio_offset + bytelen) & PAGE_MASK) == 0) {
win = ubc_alloc(&vp->v_uobj, uio->uio_offset, &bytelen,
UBC_WRITE | UBC_FAULTBUSY);
} else {
win = ubc_alloc(&vp->v_uobj, uio->uio_offset, &bytelen,
UBC_WRITE);
}
error = uiomove(win, bytelen, uio);
ubc_release(win, 0);
if (error) {
break;
}
/*
* update UVM's notion of the size now that we've
* copied the data into the vnode's pages.
*/
if (vp->v_size < uio->uio_offset) {
uvm_vnp_setsize(vp, uio->uio_offset);
}
if ((oldoff & ~(nmp->nm_wsize - 1)) !=
(uio->uio_offset & ~(nmp->nm_wsize - 1))) {
simple_lock(&vp->v_interlock);
error = VOP_PUTPAGES(vp,
trunc_page(oldoff & ~(nmp->nm_wsize - 1)),
round_page((uio->uio_offset + nmp->nm_wsize - 1) &
~(nmp->nm_wsize - 1)),
PGO_CLEANIT | PGO_WEAK);
}
} while (uio->uio_resid > 0);
if ((np->n_flag & NQNFSNONCACHE) || (ioflag & IO_SYNC)) {
simple_lock(&vp->v_interlock);
error = VOP_PUTPAGES(vp,
trunc_page(origoff & ~(nmp->nm_wsize - 1)),
round_page((uio->uio_offset + nmp->nm_wsize - 1) &
~(nmp->nm_wsize - 1)),
PGO_CLEANIT | PGO_SYNCIO);
}
return error;
}
/*
* 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;
{
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 == NULL) {
if (nfs_sigintr(nmp, NULL, p))
return (NULL);
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;
{
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, NULL, 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, NULL, 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)
struct buf *bp;
{
int i;
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] = NULL;
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;
}
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, p)
struct buf *bp;
struct proc *p;
{
struct uio *uiop;
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_BSHIFT;
if (bp->b_flags & B_READ) {
uiop->uio_rw = UIO_READ;
nfsstats.read_physios++;
error = nfs_readrpc(vp, uiop);
} else {
iomode = NFSV3WRITE_DATASYNC;
uiop->uio_rw = UIO_WRITE;
nfsstats.write_physios++;
error = nfs_writerpc(vp, uiop, &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_BSHIFT;
nfsstats.read_bios++;
error = nfs_readrpc(vp, uiop);
if (!error && 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 - ((((off_t)bp->b_blkno) << DEV_BSHIFT)
+ diff);
if (len > 0) {
len = MIN(len, uiop->uio_resid);
memset((char *)bp->b_data + diff, 0, len);
}
}
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, curproc->p_ucred);
break;
case VDIR:
nfsstats.readdir_bios++;
uiop->uio_offset = bp->b_dcookie;
if (nmp->nm_flag & NFSMNT_RDIRPLUS) {
error = nfs_readdirplusrpc(vp, uiop, curproc->p_ucred);
if (error == NFSERR_NOTSUPP)
nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
}
if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
error = nfs_readdirrpc(vp, uiop, curproc->p_ucred);
if (!error) {
bp->b_dcookie = uiop->uio_offset;
}
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 {
/*
* If B_NEEDCOMMIT is set, a commit rpc may do the trick. If not
* an actual write will have to be scheduled.
*/
io.iov_base = bp->b_data;
io.iov_len = uiop->uio_resid = bp->b_bcount;
uiop->uio_offset = (((off_t)bp->b_blkno) << DEV_BSHIFT);
uiop->uio_rw = UIO_WRITE;
nfsstats.write_bios++;
iomode = NFSV3WRITE_UNSTABLE;
error = nfs_writerpc(vp, uiop, &iomode, &must_commit);
}
bp->b_resid = uiop->uio_resid;
if (must_commit)
nfs_clearcommit(vp->v_mount);
biodone(bp);
return (error);
}
/*
* Vnode op for VM getpages.
*/
int
nfs_getpages(v)
void *v;
{
struct vop_getpages_args /* {
struct vnode *a_vp;
voff_t a_offset;
struct vm_page **a_m;
int *a_count;
int a_centeridx;
vm_prot_t a_access_type;
int a_advice;
int a_flags;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
struct uvm_object *uobj = &vp->v_uobj;
struct nfsnode *np = VTONFS(vp);
struct vm_page *pg, **pgs;
off_t origoffset;
int i, error, npages;
boolean_t v3 = NFS_ISV3(vp);
boolean_t write = (ap->a_access_type & VM_PROT_WRITE) != 0;
boolean_t locked = (ap->a_flags & PGO_LOCKED) != 0;
UVMHIST_FUNC("nfs_getpages"); UVMHIST_CALLED(ubchist);
/*
* update the cached read creds for this node.
*/
if (np->n_rcred) {
crfree(np->n_rcred);
}
np->n_rcred = curproc->p_ucred;
crhold(np->n_rcred);
/*
* call the genfs code to get the pages.
*/
npages = *ap->a_count;
error = genfs_getpages(v);
if (error || !write || !v3) {
return error;
}
/*
* this is a write fault, update the commit info.
*/
origoffset = ap->a_offset;
pgs = ap->a_m;
lockmgr(&np->n_commitlock, LK_EXCLUSIVE, NULL);
nfs_del_committed_range(vp, origoffset, npages);
nfs_del_tobecommitted_range(vp, origoffset, npages);
if (!locked) {
simple_lock(&uobj->vmobjlock);
}
for (i = 0; i < npages; i++) {
pg = pgs[i];
if (pg == NULL || pg == PGO_DONTCARE) {
continue;
}
pg->flags &= ~(PG_NEEDCOMMIT|PG_RDONLY);
}
if (!locked) {
simple_unlock(&uobj->vmobjlock);
}
lockmgr(&np->n_commitlock, LK_RELEASE, NULL);
return 0;
}
int
nfs_gop_write(struct vnode *vp, struct vm_page **pgs, int npages, int flags)
{
struct uvm_object *uobj = &vp->v_uobj;
struct nfsnode *np = VTONFS(vp);
off_t origoffset, commitoff;
uint32_t commitbytes;
int error, i;
int bytes;
boolean_t v3 = NFS_ISV3(vp);
boolean_t weak = flags & PGO_WEAK;
UVMHIST_FUNC("nfs_gop_write"); UVMHIST_CALLED(ubchist);
/* XXX for now, skip the v3 stuff. */
v3 = FALSE;
/*
* for NFSv2, just write normally.
*/
if (!v3) {
return genfs_gop_write(vp, pgs, npages, flags);
}
/*
* for NFSv3, use delayed writes and the "commit" operation
* to avoid sync writes.
*/
origoffset = pgs[0]->offset;
bytes = npages << PAGE_SHIFT;
lockmgr(&np->n_commitlock, LK_EXCLUSIVE, NULL);
if (nfs_in_committed_range(vp, origoffset, bytes)) {
goto committed;
}
if (nfs_in_tobecommitted_range(vp, origoffset, bytes)) {
if (weak) {
lockmgr(&np->n_commitlock, LK_RELEASE, NULL);
return 0;
} else {
commitoff = np->n_pushlo;
commitbytes = (uint32_t)(np->n_pushhi - np->n_pushlo);
goto commit;
}
} else {
commitoff = origoffset;
commitbytes = npages << PAGE_SHIFT;
}
simple_lock(&uobj->vmobjlock);
for (i = 0; i < npages; i++) {
pgs[i]->flags |= PG_NEEDCOMMIT|PG_RDONLY;
pgs[i]->flags &= ~PG_CLEAN;
}
simple_unlock(&uobj->vmobjlock);
lockmgr(&np->n_commitlock, LK_RELEASE, NULL);
error = genfs_gop_write(vp, pgs, npages, flags);
if (error) {
return error;
}
lockmgr(&np->n_commitlock, LK_EXCLUSIVE, NULL);
if (weak) {
nfs_add_tobecommitted_range(vp, origoffset,
npages << PAGE_SHIFT);
} else {
commit:
error = nfs_commit(vp, commitoff, commitbytes, curproc);
nfs_del_tobecommitted_range(vp, commitoff, commitbytes);
committed:
simple_lock(&uobj->vmobjlock);
for (i = 0; i < npages; i++) {
pgs[i]->flags &= ~(PG_NEEDCOMMIT|PG_RDONLY);
}
simple_unlock(&uobj->vmobjlock);
}
lockmgr(&np->n_commitlock, LK_RELEASE, NULL);
return error;
}
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