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|
/* $OpenBSD: nfs_bio.c,v 1.66 2009/08/27 23:39:46 thib Exp $ */
/* $NetBSD: nfs_bio.c,v 1.25.4.2 1996/07/08 20:47:04 jtc 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. 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/mount.h>
#include <sys/kernel.h>
#include <sys/namei.h>
#include <sys/queue.h>
#include <sys/time.h>
#include <uvm/uvm_extern.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsmount.h>
#include <nfs/nfsnode.h>
#include <nfs/nfs_var.h>
extern struct nfsstats nfsstats;
/*
* Vnode op for read using bio
* Any similarity to readip() is purely coincidental
*/
int
nfs_bioread(vp, uio, ioflag, cred)
struct vnode *vp;
struct uio *uio;
int ioflag;
struct ucred *cred;
{
struct nfsnode *np = VTONFS(vp);
int biosize, diff;
struct buf *bp = NULL, *rabp;
struct vattr vattr;
struct proc *p;
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
daddr64_t lbn, bn, rabn;
caddr_t baddr;
int got_buf = 0, nra, error = 0, n = 0, on = 0, not_readin;
off_t offdiff;
#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)
return (EINVAL);
p = uio->uio_procp;
if ((nmp->nm_flag & (NFSMNT_NFSV3 | NFSMNT_GOTFSINFO)) == NFSMNT_NFSV3)
(void)nfs_fsinfo(nmp, vp, cred, p);
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 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.
*/
if (np->n_flag & NMODIFIED) {
NFS_INVALIDATE_ATTRCACHE(np);
error = VOP_GETATTR(vp, &vattr, cred, p);
if (error)
return (error);
np->n_mtime = vattr.va_mtime;
} else {
error = VOP_GETATTR(vp, &vattr, cred, p);
if (error)
return (error);
if (timespeccmp(&np->n_mtime, &vattr.va_mtime, !=)) {
error = nfs_vinvalbuf(vp, V_SAVE, cred, p);
if (error)
return (error);
np->n_mtime = vattr.va_mtime;
}
}
/*
* update the cache read creds for this vnode
*/
if (np->n_rcred)
crfree(np->n_rcred);
np->n_rcred = cred;
crhold(cred);
do {
if ((vp->v_flag & VROOT) && vp->v_type == VLNK) {
return (nfs_readlinkrpc(vp, uio, cred));
}
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_numaiods > 0 && nmp->nm_readahead > 0) {
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)) {
rabp->b_flags |= B_INVAL;
brelse(rabp);
}
} else
brelse(rabp);
}
}
}
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, 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) {
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;
}
}
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, 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;
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;
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 *ap = v;
int biosize;
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 buf *bp;
struct vattr vattr;
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
daddr64_t lbn, bn;
int n, on, error = 0, extended = 0, wrotedta = 0, truncated = 0;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_WRITE)
panic("nfs_write mode");
if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
panic("nfs_write proc");
#endif
if (vp->v_type != VREG)
return (EIO);
if (np->n_flag & NWRITEERR) {
np->n_flag &= ~NWRITEERR;
return (np->n_error);
}
if ((nmp->nm_flag & (NFSMNT_NFSV3 | NFSMNT_GOTFSINFO)) == NFSMNT_NFSV3)
(void)nfs_fsinfo(nmp, vp, cred, p);
if (ioflag & (IO_APPEND | IO_SYNC)) {
if (np->n_flag & NMODIFIED) {
NFS_INVALIDATE_ATTRCACHE(np);
error = nfs_vinvalbuf(vp, V_SAVE, cred, p);
if (error)
return (error);
}
if (ioflag & IO_APPEND) {
NFS_INVALIDATE_ATTRCACHE(np);
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_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 cache write creds for this node.
*/
if (np->n_wcred)
crfree(np->n_wcred);
np->n_wcred = cred;
crhold(cred);
/*
* 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
*/
uvm_vnp_uncache(vp);
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);
np->n_flag |= NMODIFIED;
if (uio->uio_offset + n > np->n_size) {
np->n_size = uio->uio_offset + n;
uvm_vnp_setsize(vp, (u_long)np->n_size);
extended = 1;
} else if (uio->uio_offset + n < np->n_size)
truncated = 1;
/*
* 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;
}
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);
}
wrotedta = 1;
/*
* Since this block is being modified, it must be written
* again and not just committed.
*/
if (NFS_ISV3(vp)) {
rw_enter_write(&np->n_commitlock);
if (bp->b_flags & B_NEEDCOMMIT) {
bp->b_flags &= ~B_NEEDCOMMIT;
nfs_del_tobecommitted_range(vp, bp);
}
nfs_del_committed_range(vp, bp);
rw_exit_write(&np->n_commitlock);
} else
bp->b_flags &= ~B_NEEDCOMMIT;
if (ioflag & IO_SYNC) {
bp->b_proc = p;
error = VOP_BWRITE(bp);
if (error)
return (error);
} else if ((n + on) == biosize) {
bp->b_proc = NULL;
bp->b_flags |= B_ASYNC;
(void)nfs_writebp(bp, 0);
} else {
bdwrite(bp);
}
} while (uio->uio_resid > 0 && n > 0);
if (wrotedta)
VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0) |
(truncated ? NOTE_TRUNCATE : 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;
daddr64_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(struct vnode *vp, int flags, struct ucred *cred, struct proc *p)
{
struct nfsmount *nmp= VFSTONFS(vp->v_mount);
struct nfsnode *np = VTONFS(vp);
int error, sintr, stimeo;
error = sintr = stimeo = 0;
if (ISSET(nmp->nm_flag, NFSMNT_INT)) {
sintr = PCATCH;
stimeo = 2 * hz;
}
/* First wait for any other process doing a flush to complete. */
while (np->n_flag & NFLUSHINPROG) {
np->n_flag |= NFLUSHWANT;
error = tsleep(&np->n_flag, PRIBIO|sintr, "nfsvinval", stimeo);
if (error && sintr && nfs_sigintr(nmp, NULL, p))
return (EINTR);
}
/* Now, flush as required. */
np->n_flag |= NFLUSHINPROG;
error = vinvalbuf(vp, flags, cred, p, sintr, 0);
while (error) {
if (sintr && nfs_sigintr(nmp, NULL, p)) {
np->n_flag &= ~NFLUSHINPROG;
if (np->n_flag & NFLUSHWANT) {
np->n_flag &= ~NFLUSHWANT;
wakeup(&np->n_flag);
}
return (EINTR);
}
error = vinvalbuf(vp, flags, cred, p, 0, stimeo);
}
np->n_flag &= ~(NMODIFIED | NFLUSHINPROG);
if (np->n_flag & NFLUSHWANT) {
np->n_flag &= ~NFLUSHWANT;
wakeup(&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(struct buf *bp)
{
struct nfs_aiod *aiod;
struct nfsmount *nmp;
int gotone, error;
aiod = NULL;
nmp = VFSTONFS(bp->b_vp->v_mount);
gotone = error = 0;
mtx_enter(&nfs_aiodl_mtx);
aiod = LIST_FIRST(&nfs_aiods_idle);
if (aiod) {
/*
* Found an available aiod, wake it up and send
* it to work on this mount.
*/
LIST_REMOVE(aiod, nad_idle);
mtx_leave(&nfs_aiodl_mtx);
aiod->nad_flags |= NFSAIOD_WAKEUP;
gotone = 1;
KASSERT(aiod->nad_mnt == NULL);
aiod->nad_mnt = nmp;
nmp->nm_naiods++;
wakeup_one(aiod);
} else {
mtx_leave(&nfs_aiodl_mtx);
}
/*
* If no aiod's are available, check if theres already an
* aiod assoicated with this mount, if so it will process
* this buf.
*/
if (!gotone && nmp->nm_naiods > 0)
gotone = 1;
/*
* If we still don't have an aiod to process this buffer,
* force it sync.
*/
if (!gotone)
goto out;
/*
* Make sure we don't queue up too much.
* TODO: Look into implementing migration for aiods.
*/
if (nmp->nm_bufqlen >= nfs_aiodbufqmax) {
if (aiod != NULL) {
aiod->nad_flags &= ~NFSAIOD_WAKEUP;
aiod->nad_mnt = NULL;
mtx_enter(&nfs_aiodl_mtx);
LIST_INSERT_HEAD(&nfs_aiods_idle, aiod, nad_idle);
mtx_leave(&nfs_aiodl_mtx);
}
goto out;
}
/* Finally, queue the buffer and return. */
if ((bp->b_flags & B_READ) == 0)
bp->b_flags |= B_WRITEINPROG;
TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
nmp->nm_bufqlen++;
return (0);
out:
nfsstats.forcedsync++;
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 s, 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) {
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++;
bcstats.pendingreads++;
bcstats.numreads++;
error = nfs_readrpc(vp, uiop);
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 - ((((off_t)bp->b_blkno) << DEV_BSHIFT)
+ 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) &&
(timespeccmp(&np->n_mtime, &np->n_vattr.va_mtime, !=))) {
uprintf("Process killed due to text file modification\n");
psignal(p, SIGKILL);
}
break;
case VLNK:
uiop->uio_offset = (off_t)0;
nfsstats.readlink_bios++;
bcstats.pendingreads++;
bcstats.numreads++;
error = nfs_readlinkrpc(vp, uiop, curproc->p_ucred);
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++;
bcstats.pendingwrites++;
bcstats.numwrites++;
if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE)) == B_ASYNC)
iomode = NFSV3WRITE_UNSTABLE;
else
iomode = NFSV3WRITE_FILESYNC;
bp->b_flags |= B_WRITEINPROG;
error = nfs_writerpc(vp, uiop, &iomode, &must_commit);
rw_enter_write(&np->n_commitlock);
if (!error && iomode == NFSV3WRITE_UNSTABLE) {
bp->b_flags |= B_NEEDCOMMIT;
nfs_add_tobecommitted_range(vp, bp);
} else {
bp->b_flags &= ~B_NEEDCOMMIT;
nfs_del_committed_range(vp, bp);
}
rw_exit_write(&np->n_commitlock);
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))) {
s = splbio();
buf_dirty(bp);
splx(s);
if (!(bp->b_flags & B_ASYNC) && 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);
s = splbio();
biodone(bp);
splx(s);
return (error);
}
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