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freebsd-dev/sys/nfs/nfs_bio.c
Bruce Evans 4c4918c9e4 Avoid an egcs pessimization for 64-bit signed division on i386's. 
Pre-2.8 versions of gcc generate a call to __divdi3() for all 64-bit
signed divisions, but egcs optimizes them to a shift and fixup when
the divisor is a constant power of 2.  Unfortunately, it generates
a call to __cmpdi2() for the fixup, although all except possibly
ancient versions of gcc and egcs do ordinary 64-bit comparisons
inline.
1998-06-14 15:52:00 +00:00

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/*
* 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
* $Id: nfs_bio.c,v 1.58 1998/06/01 11:32:53 peter Exp $
*/
#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 <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_prot.h>
#include <vm/vm_page.h>
#include <vm/vm_object.h>
#include <vm/vm_pager.h>
#include <vm/vnode_pager.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>
static struct buf *nfs_getcacheblk __P((struct vnode *vp, daddr_t bn, int size,
struct proc *p));
static void nfs_prot_buf __P((struct buf *bp, int off, int n));
extern int nfs_numasync;
extern struct nfsstats nfsstats;
/*
* Vnode op for VM getpages.
*/
int
nfs_getpages(ap)
struct vop_getpages_args /* {
struct vnode *a_vp;
vm_page_t *a_m;
int a_count;
int a_reqpage;
vm_ooffset_t a_offset;
} */ *ap;
{
int i, error, nextoff, size, toff, npages, count;
struct uio uio;
struct iovec iov;
vm_page_t m;
vm_offset_t kva;
struct buf *bp;
struct vnode *vp;
struct proc *p;
struct ucred *cred;
struct nfsmount *nmp;
vm_page_t *pages;
vp = ap->a_vp;
p = curproc; /* XXX */
cred = curproc->p_ucred; /* XXX */
nmp = VFSTONFS(vp->v_mount);
pages = ap->a_m;
count = ap->a_count;
if (vp->v_object == NULL) {
printf("nfs_getpages: called with non-merged cache vnode??\n");
return VM_PAGER_ERROR;
}
if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
(nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
(void)nfs_fsinfo(nmp, vp, cred, p);
/*
* We use only the kva address for the buffer, but this is extremely
* convienient and fast.
*/
bp = getpbuf();
npages = btoc(count);
kva = (vm_offset_t) bp->b_data;
pmap_qenter(kva, pages, npages);
iov.iov_base = (caddr_t) kva;
iov.iov_len = count;
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
uio.uio_resid = count;
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_rw = UIO_READ;
uio.uio_procp = p;
error = nfs_readrpc(vp, &uio, cred);
pmap_qremove(kva, npages);
relpbuf(bp);
if (error && (uio.uio_resid == count))
return VM_PAGER_ERROR;
size = count - uio.uio_resid;
for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
vm_page_t m;
nextoff = toff + PAGE_SIZE;
m = pages[i];
m->flags &= ~PG_ZERO;
if (nextoff <= size) {
m->valid = VM_PAGE_BITS_ALL;
m->dirty = 0;
} else {
int nvalid = ((size + DEV_BSIZE - 1) - toff) & ~(DEV_BSIZE - 1);
vm_page_set_validclean(m, 0, nvalid);
}
if (i != ap->a_reqpage) {
/*
* Whether or not to leave the page activated is up in
* the air, but we should put the page on a page queue
* somewhere (it already is in the object). Result:
* It appears that emperical results show that
* deactivating pages is best.
*/
/*
* Just in case someone was asking for this page we
* now tell them that it is ok to use.
*/
if (!error) {
if (m->flags & PG_WANTED)
vm_page_activate(m);
else
vm_page_deactivate(m);
PAGE_WAKEUP(m);
} else {
vnode_pager_freepage(m);
}
}
}
return 0;
}
/*
* Vnode op for VM putpages.
*/
int
nfs_putpages(ap)
struct vop_putpages_args /* {
struct vnode *a_vp;
vm_page_t *a_m;
int a_count;
int a_sync;
int *a_rtvals;
vm_ooffset_t a_offset;
} */ *ap;
{
struct uio uio;
struct iovec iov;
vm_page_t m;
vm_offset_t kva;
struct buf *bp;
int iomode, must_commit, i, error, npages, count;
int *rtvals;
struct vnode *vp;
struct proc *p;
struct ucred *cred;
struct nfsmount *nmp;
vm_page_t *pages;
vp = ap->a_vp;
p = curproc; /* XXX */
cred = curproc->p_ucred; /* XXX */
nmp = VFSTONFS(vp->v_mount);
pages = ap->a_m;
count = ap->a_count;
rtvals = ap->a_rtvals;
npages = btoc(count);
if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
(nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
(void)nfs_fsinfo(nmp, vp, cred, p);
for (i = 0; i < npages; i++) {
rtvals[i] = VM_PAGER_AGAIN;
}
/*
* We use only the kva address for the buffer, but this is extremely
* convienient and fast.
*/
bp = getpbuf();
kva = (vm_offset_t) bp->b_data;
pmap_qenter(kva, pages, npages);
iov.iov_base = (caddr_t) kva;
iov.iov_len = count;
uio.uio_iov = &iov;
uio.uio_iovcnt = 1;
uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
uio.uio_resid = count;
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_rw = UIO_WRITE;
uio.uio_procp = p;
if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0)
iomode = NFSV3WRITE_UNSTABLE;
else
iomode = NFSV3WRITE_FILESYNC;
error = nfs_writerpc(vp, &uio, cred, &iomode, &must_commit);
pmap_qremove(kva, npages);
relpbuf(bp);
if (!error) {
int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE;
for (i = 0; i < nwritten; i++) {
rtvals[i] = VM_PAGER_OK;
pages[i]->dirty = 0;
}
if (must_commit)
nfs_clearcommit(vp->v_mount);
}
return rtvals[0];
}
/*
* Vnode op for read using bio
*/
int
nfs_bioread(vp, uio, ioflag, cred, getpages)
register struct vnode *vp;
register struct uio *uio;
int ioflag;
struct ucred *cred;
int getpages;
{
register struct nfsnode *np = VTONFS(vp);
register int biosize, diff, i;
struct buf *bp = 0, *rabp;
struct vattr vattr;
struct proc *p;
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
daddr_t lbn, rabn;
int bufsize;
int nra, error = 0, n = 0, on = 0, not_readin;
#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) /* XXX VDIR cookies can be negative */
return (EINVAL);
p = uio->uio_procp;
if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
(nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
(void)nfs_fsinfo(nmp, vp, cred, p);
if (vp->v_type != VDIR &&
(uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
return (EFBIG);
biosize = vp->v_mount->mnt_stat.f_iosize;
/*
* 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) {
if (np->n_flag & NMODIFIED) {
if (vp->v_type != VREG) {
if (vp->v_type != VDIR)
panic("nfs: bioread, not dir");
nfs_invaldir(vp);
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_invaldir(vp);
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_invaldir(vp);
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_invaldir(vp);
error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
if (error)
return (error);
}
}
if (np->n_flag & NQNFSNONCACHE) {
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);
};
}
switch (vp->v_type) {
case VREG:
nfsstats.biocache_reads++;
lbn = uio->uio_offset / biosize;
on = uio->uio_offset & (biosize - 1);
not_readin = 1;
/*
* Start the read ahead(s), as required.
*/
if (nfs_numasync > 0 && nmp->nm_readahead > 0) {
for (nra = 0; nra < nmp->nm_readahead &&
(off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) {
rabn = lbn + 1 + nra;
if (!incore(vp, rabn)) {
rabp = nfs_getcacheblk(vp, rabn, biosize, p);
if (!rabp)
return (EINTR);
if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
rabp->b_flags |= (B_READ | B_ASYNC);
vfs_busy_pages(rabp, 0);
if (nfs_asyncio(rabp, cred)) {
rabp->b_flags |= B_INVAL|B_ERROR;
vfs_unbusy_pages(rabp);
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.
*/
again:
bufsize = biosize;
if ((off_t)(lbn + 1) * biosize > np->n_size &&
(off_t)(lbn + 1) * biosize - np->n_size < biosize) {
bufsize = np->n_size - lbn * biosize;
bufsize = (bufsize + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
}
bp = nfs_getcacheblk(vp, lbn, bufsize, p);
if (!bp)
return (EINTR);
/*
* If we are being called from nfs_getpages, we must
* make sure the buffer is a vmio buffer. The vp will
* already be setup for vmio but there may be some old
* non-vmio buffers attached to it.
*/
if (getpages && !(bp->b_flags & B_VMIO)) {
#ifdef DIAGNOSTIC
printf("nfs_bioread: non vmio buf found, discarding\n");
#endif
bp->b_flags |= B_NOCACHE;
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;
}
if ((bp->b_flags & B_CACHE) == 0) {
bp->b_flags |= B_READ;
bp->b_flags &= ~(B_DONE | B_ERROR | B_INVAL);
not_readin = 0;
vfs_busy_pages(bp, 0);
error = nfs_doio(bp, cred, p);
if (error) {
brelse(bp);
return (error);
}
}
if (bufsize > on) {
n = min((unsigned)(bufsize - on), uio->uio_resid);
} else {
n = 0;
}
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) {
bp->b_flags |= B_NOCACHE;
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_CACHE) == 0) {
bp->b_flags |= B_READ;
vfs_busy_pages(bp, 0);
error = nfs_doio(bp, cred, p);
if (error) {
bp->b_flags |= B_ERROR;
brelse(bp);
return (error);
}
}
n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
on = 0;
break;
case VDIR:
nfsstats.biocache_readdirs++;
if (np->n_direofoffset
&& uio->uio_offset >= np->n_direofoffset) {
return (0);
}
lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, p);
if (!bp)
return (EINTR);
if ((bp->b_flags & B_CACHE) == 0) {
bp->b_flags |= B_READ;
vfs_busy_pages(bp, 0);
error = nfs_doio(bp, cred, p);
if (error) {
brelse(bp);
}
while (error == NFSERR_BAD_COOKIE) {
nfs_invaldir(vp);
error = nfs_vinvalbuf(vp, 0, cred, p, 1);
/*
* Yuck! The directory has been modified on the
* server. The only way to get the block is by
* reading from the beginning to get all the
* offset cookies.
*/
for (i = 0; i <= lbn && !error; i++) {
if (np->n_direofoffset
&& (i * NFS_DIRBLKSIZ) >= np->n_direofoffset)
return (0);
bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, p);
if (!bp)
return (EINTR);
if ((bp->b_flags & B_DONE) == 0) {
bp->b_flags |= B_READ;
vfs_busy_pages(bp, 0);
error = nfs_doio(bp, cred, p);
if (error) {
brelse(bp);
} else if (i < lbn) {
brelse(bp);
}
}
}
}
if (error)
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.)
*/
if (nfs_numasync > 0 && nmp->nm_readahead > 0 &&
(np->n_direofoffset == 0 ||
(lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
!(np->n_flag & NQNFSNONCACHE) &&
!incore(vp, lbn + 1)) {
rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, p);
if (rabp) {
if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
rabp->b_flags |= (B_READ | B_ASYNC);
vfs_busy_pages(rabp, 0);
if (nfs_asyncio(rabp, cred)) {
rabp->b_flags |= B_INVAL|B_ERROR;
vfs_unbusy_pages(rabp);
brelse(rabp);
}
} else {
brelse(rabp);
}
}
}
/*
* Make sure we use a signed variant of min() since
* the second term may be negative.
*/
n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
break;
default:
printf(" nfs_bioread: type %x unexpected\n",vp->v_type);
break;
};
if (n > 0) {
error = uiomove(bp->b_data + 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;
break;
default:
printf(" nfs_bioread: type %x unexpected\n",vp->v_type);
}
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n > 0);
return (error);
}
static void
nfs_prot_buf(bp, off, n)
struct buf *bp;
int off;
int n;
{
int pindex, boff, end;
if ((bp->b_flags & B_VMIO) == 0)
return;
end = round_page(off + n);
for (boff = trunc_page(off); boff < end; boff += PAGE_SIZE) {
pindex = boff >> PAGE_SHIFT;
vm_page_protect(bp->b_pages[pindex], VM_PROT_NONE);
}
}
/*
* Vnode op for write using bio
*/
int
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 = VFSTONFS(vp->v_mount);
daddr_t lbn;
int bufsize;
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) != 0 &&
(nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
(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 = vp->v_mount->mnt_stat.f_iosize;
do {
/*
* 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);
again:
if (uio->uio_offset + n > np->n_size) {
np->n_size = uio->uio_offset + n;
np->n_flag |= NMODIFIED;
vnode_pager_setsize(vp, (u_long)np->n_size);
}
bufsize = biosize;
if ((lbn + 1) * biosize > np->n_size) {
bufsize = np->n_size - lbn * biosize;
bufsize = (bufsize + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
}
bp = nfs_getcacheblk(vp, lbn, bufsize, p);
if (!bp)
return (EINTR);
if (bp->b_wcred == NOCRED) {
crhold(cred);
bp->b_wcred = cred;
}
np->n_flag |= NMODIFIED;
if ((bp->b_blkno * DEV_BSIZE) + bp->b_dirtyend > np->n_size) {
bp->b_dirtyend = np->n_size - (bp->b_blkno * DEV_BSIZE);
}
/*
* 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);
}
/*
* This will keep the buffer and mmaped regions more coherent.
*/
nfs_prot_buf(bp, on, n);
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;
if (ioflag & IO_INVAL)
bp->b_flags |= B_INVAL;
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.
*/
static struct buf *
nfs_getcacheblk(vp, bn, size, p)
struct vnode *vp;
daddr_t bn;
int size;
struct proc *p;
{
register struct buf *bp;
struct mount *mp;
struct nfsmount *nmp;
mp = vp->v_mount;
nmp = VFSTONFS(mp);
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);
if( vp->v_type == VREG) {
int biosize;
biosize = mp->mnt_stat.f_iosize;
bp->b_blkno = (bn * biosize) / DEV_BSIZE;
}
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 (vp->v_flag & VXLOCK) {
return (0);
}
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;
{
struct nfsmount *nmp;
int i;
int gotiod;
int slpflag = 0;
int slptimeo = 0;
int 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_DPF(ASYNCIO,
("nfs_asyncio: waking iod %d for mount %p\n",
i, nmp));
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) {
if (nmp->nm_bufqiods > 0) {
NFS_DPF(ASYNCIO,
("nfs_asyncio: %d iods are already processing mount %p\n",
nmp->nm_bufqiods, nmp));
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) {
NFS_DPF(ASYNCIO,
("nfs_asyncio: waiting for mount %p queue to drain\n", nmp));
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) {
NFS_DPF(ASYNCIO,
("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
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.
*/
NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n"));
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 {
int com;
iomode = NFSV3WRITE_DATASYNC;
uiop->uio_rw = UIO_WRITE;
nfsstats.write_physios++;
error = nfs_writerpc(vp, uiop, cr, &iomode, &com);
}
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_flag |= P_NOSWAP;
}
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 = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
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);
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 (((bp->b_blkno * DEV_BSIZE) + bp->b_dirtyend) > np->n_size)
bp->b_dirtyend = np->n_size - (bp->b_blkno * DEV_BSIZE);
if (bp->b_dirtyend > bp->b_dirtyoff) {
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_CLUSTER)) == B_ASYNC)
iomode = NFSV3WRITE_UNSTABLE;
else
iomode = NFSV3WRITE_FILESYNC;
bp->b_flags |= B_WRITEINPROG;
error = nfs_writerpc(vp, uiop, cr, &iomode, &must_commit);
if (!error && iomode == NFSV3WRITE_UNSTABLE) {
bp->b_flags |= B_NEEDCOMMIT;
if (bp->b_dirtyoff == 0
&& bp->b_dirtyend == bp->b_bufsize)
bp->b_flags |= B_CLUSTEROK;
} 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))) {
int s;
bp->b_flags &= ~(B_INVAL|B_NOCACHE);
++numdirtybuffers;
bp->b_flags |= B_DELWRI;
s = splbio();
reassignbuf(bp, vp);
splx(s);
if ((bp->b_flags & B_ASYNC) == 0)
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;
}
} else {
bp->b_resid = 0;
biodone(bp);
return (0);
}
}
bp->b_resid = uiop->uio_resid;
if (must_commit)
nfs_clearcommit(vp->v_mount);
biodone(bp);
return (error);
}
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