+++ /dev/null
-/*
- * This Cplant(TM) source code is the property of Sandia National
- * Laboratories.
- *
- * This Cplant(TM) source code is copyrighted by Sandia National
- * Laboratories.
- *
- * The redistribution of this Cplant(TM) source code is subject to the
- * terms of the GNU Lesser General Public License
- * (see cit/LGPL or http://www.gnu.org/licenses/lgpl.html)
- *
- * Cplant(TM) Copyright 1998-2004 Sandia Corporation.
- * Under the terms of Contract DE-AC04-94AL85000, there is a non-exclusive
- * license for use of this work by or on behalf of the US Government.
- * Export of this program may require a license from the United States
- * Government.
- */
-
-/*
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * Questions or comments about this library should be sent to:
- *
- * Lee Ward
- * Sandia National Laboratories, New Mexico
- * P.O. Box 5800
- * Albuquerque, NM 87185-1110
- *
- * lee@sandia.gov
- */
-
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <assert.h>
-#include <sys/uio.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/queue.h>
-
-#include "sysio.h"
-#include "xtio.h"
-
-/*
- * Extent-vector IO support.
- */
-
-/*
- * Arguments to IO vector enumerator callback when used by _sysio_doio().
- */
-struct doio_helper_args {
- ssize_t (*f)(void *, size_t, _SYSIO_OFF_T, void *); /* base func */
- void *arg; /* caller arg */
-};
-
-/*
- * General help validating strided-IO vectors.
- *
- * A driver may call this to make sure underflow/overflow of an off_t can't
- * occur and overflow of a ssize_t can't occur when writing. The sum
- * of the reconciled transfer length is returned or some appropriate
- * error depending on underflow/overflow.
- *
- * The following algorithm assumes:
- *
- * a) sizeof(size_t) >= sizeof(ssize_t)
- * b) 2's complement arithmetic
- * c) The compiler won't optimize away code because it's developers
- * believed that something with an undefined result in `C' can't happen.
- */
-ssize_t
-_sysio_validx(const struct intnl_xtvec *xtv, size_t xtvlen,
- const struct iovec *iov, size_t iovlen,
- _SYSIO_OFF_T limit)
-{
- ssize_t acc, cc;
- struct iovec iovec;
- struct intnl_xtvec xtvec;
- _SYSIO_OFF_T off;
-
- if (!(xtvlen && iovlen))
- return -EINVAL;
-
- acc = 0;
- xtvec.xtv_len = iovec.iov_len = 0;
- do {
- while (!xtvec.xtv_len) {
- if (!xtvlen--)
- break;
- if (!xtv->xtv_len) {
- xtv++;
- continue;
- }
- xtvec = *xtv++;
- if (xtvec.xtv_off < 0)
- return -EINVAL;
- }
- if (!xtvec.xtv_len)
- break;
- do {
- while (!iovec.iov_len) {
- if (!iovlen--)
- break;
- if (!iov->iov_len) {
- iov++;
- continue;
- }
- iovec = *iov++;
- }
- if (!iovec.iov_len)
- break;
- cc = iovec.iov_len;
- if (cc < 0)
- return -EINVAL;
- if ((size_t )cc > xtvec.xtv_len)
- cc = xtvec.xtv_len;
- xtvec.xtv_len -= cc;
- iovec.iov_len -= cc;
- off = xtvec.xtv_off + cc;
- if (xtvec.xtv_off && off <= xtvec.xtv_off)
- return off < 0 ? -EINVAL : -EOVERFLOW;
- if (off > limit)
- return -EFBIG;
- xtvec.xtv_off = off;
- cc += acc;
- if (acc && (cc <= acc))
- return -EINVAL;
- acc = cc;
- } while (xtvec.xtv_len && iovlen);
- } while ((xtvlen || xtvec.xtv_len) && iovlen);
- return acc;
-}
-
-/*
- */
-ssize_t
-_sysio_enumerate_extents(const struct intnl_xtvec *xtv, size_t xtvlen,
- const struct iovec *iov, size_t iovlen,
- ssize_t (*f)(const struct iovec *, int,
- _SYSIO_OFF_T,
- ssize_t,
- void *),
- void *arg)
-{
- ssize_t acc, tmp, cc;
- struct iovec iovec;
- struct intnl_xtvec xtvec;
- const struct iovec *start;
- _SYSIO_OFF_T off;
- size_t n;
- size_t remain;
-
- acc = 0;
- iovec.iov_len = 0;
- while (xtvlen) {
- /*
- * Coalesce contiguous extent vector entries.
- */
- off = xtvec.xtv_off = xtv->xtv_off;
- off += xtvec.xtv_len = xtv->xtv_len;
- while (++xtv, --xtvlen) {
- if (off != xtv->xtv_off) {
- /*
- * Not contiguous.
- */
- break;
- }
- if (!xtv->xtv_len) {
- /*
- * Zero length.
- */
- continue;
- }
- off += xtv->xtv_len;
- xtvec.xtv_len += xtv->xtv_len;
- }
- while (xtvec.xtv_len) {
- if (iovec.iov_len) {
- tmp = iovec.iov_len;
- if (iovec.iov_len > xtvec.xtv_len)
- iovec.iov_len = xtvec.xtv_len;
- cc =
- (*f)(&iovec, 1,
- xtvec.xtv_off,
- xtvec.xtv_len,
- arg);
- if (cc <= 0) {
- if (acc)
- return acc;
- return cc;
- }
- iovec.iov_base = (char *)iovec.iov_base + cc;
- iovec.iov_len = tmp - cc;
- tmp = cc + acc;
- if (acc && tmp <= acc)
- abort(); /* paranoia */
- acc = tmp;
- } else if (iovlen) {
- start = iov;
- n = xtvec.xtv_len;
- do {
- if (iov->iov_len > n) {
- /*
- * That'll do.
- */
- break;
- }
- n -= iov->iov_len;
- iov++;
- } while (--iovlen);
- if (iov == start) {
- iovec = *iov++;
- iovlen--;
- continue;
- }
- remain = xtvec.xtv_len - n;
- cc =
- (*f)(start, iov - start,
- xtvec.xtv_off,
- remain,
- arg);
- if (cc <= 0) {
- if (acc)
- return acc;
- return cc;
- }
-
- tmp = cc + acc;
- if (acc && tmp <= acc)
- abort(); /* paranoia */
- acc = tmp;
-
- remain -= cc;
- if (remain)
- return acc; /* short */
- } else
- return acc; /* short out */
- xtvec.xtv_off += cc;
- xtvec.xtv_len -= cc;
- }
- }
- return acc;
-}
-
-ssize_t
-_sysio_enumerate_iovec(const struct iovec *iov, size_t count,
- _SYSIO_OFF_T off,
- ssize_t limit,
- ssize_t (*f)(void *, size_t, _SYSIO_OFF_T, void *),
- void *arg)
-{
- ssize_t acc, cc;
- size_t n;
- unsigned indx;
- size_t remain;
-
- if (!count)
- return -EINVAL;
- assert(limit >= 0);
- acc = 0;
- n = limit;
- for (indx = 0; n && indx < count; indx++) {
- if (iov[indx].iov_len < n) {
- cc = (ssize_t )iov[indx].iov_len;
- if (cc < 0)
- return -EINVAL;
- } else
- cc = (ssize_t )n;
- if (!cc)
- continue;
- n -= cc;
- cc += acc;
- if (acc && cc <= acc)
- return -EINVAL;
- acc = cc;
- }
- if (!acc)
- return 0;
- acc = 0;
- do {
- if (!iov->iov_len) {
- iov++;
- continue;
- }
- n =
- iov->iov_len < (size_t )limit
- ? iov->iov_len
- : (size_t )limit;
- cc = (*f)(iov->iov_base, n, off, arg);
- if (cc <= 0) {
- if (acc)
- return acc;
- return cc;
- }
- off += cc;
- limit -= cc;
- remain = iov->iov_len - cc;
- cc += acc;
- if (acc && cc <= acc)
- abort(); /* bad driver! */
- acc = cc;
- if (remain || !limit)
- break; /* short/limited read */
- iov++;
- } while (--count);
- return acc;
-}
-
-static ssize_t
-_sysio_doio_helper(const struct iovec *iov, int count,
- _SYSIO_OFF_T off,
- ssize_t limit,
- struct doio_helper_args *args)
-{
-
- return _sysio_enumerate_iovec(iov, count,
- off, limit,
- args->f,
- args->arg);
-}
-
-/*
- * A meta-driver for the whole strided-io process. Appropriate when
- * the driver can't handle anything but simple p{read,write}-like
- * interface.
- */
-ssize_t
-_sysio_doio(const struct intnl_xtvec *xtv, size_t xtvlen,
- const struct iovec *iov, size_t iovlen,
- ssize_t (*f)(void *, size_t, _SYSIO_OFF_T, void *),
- void *arg)
-{
- struct doio_helper_args arguments;
-
- arguments.f = f;
- arguments.arg = arg;
- return _sysio_enumerate_extents(xtv, xtvlen,
- iov, iovlen,
- (ssize_t (*)(const struct iovec *, int,
- _SYSIO_OFF_T,
- ssize_t,
- void *))_sysio_doio_helper,
- &arguments);
-}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff