NetBSD-5.0.2/sys/ufs/ext2fs/ext2fs_readwrite.c
/* $NetBSD: ext2fs_readwrite.c,v 1.52 2008/05/16 09:22:00 hannken Exp $ */
/*-
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*
* @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94
* Modified for ext2fs by Manuel Bouyer.
*/
/*-
* Copyright (c) 1997 Manuel Bouyer.
*
* 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 Manuel Bouyer.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94
* Modified for ext2fs by Manuel Bouyer.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ext2fs_readwrite.c,v 1.52 2008/05/16 09:22:00 hannken Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/signalvar.h>
#include <sys/kauth.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>
#include <ufs/ext2fs/ext2fs.h>
#include <ufs/ext2fs/ext2fs_extern.h>
#define doclusterread 0 /* XXX underway */
#define doclusterwrite 0
/*
* Vnode op for reading.
*/
/* ARGSUSED */
int
ext2fs_read(void *v)
{
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct vnode *vp;
struct inode *ip;
struct uio *uio;
struct m_ext2fs *fs;
struct buf *bp;
struct ufsmount *ump;
void *win;
vsize_t bytelen;
daddr_t lbn, nextlbn;
off_t bytesinfile;
long size, xfersize, blkoffset;
int error, flags;
vp = ap->a_vp;
ip = VTOI(vp);
ump = ip->i_ump;
uio = ap->a_uio;
error = 0;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("%s: mode", "ext2fs_read");
if (vp->v_type == VLNK) {
if (ext2fs_size(ip) < ump->um_maxsymlinklen ||
(ump->um_maxsymlinklen == 0 && ip->i_e2fs_nblock == 0))
panic("%s: short symlink", "ext2fs_read");
} else if (vp->v_type != VREG && vp->v_type != VDIR)
panic("%s: type %d", "ext2fs_read", vp->v_type);
#endif
fs = ip->i_e2fs;
if ((u_int64_t)uio->uio_offset > ump->um_maxfilesize)
return (EFBIG);
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset >= ext2fs_size(ip))
goto out;
if (vp->v_type == VREG) {
const int advice = IO_ADV_DECODE(ap->a_ioflag);
while (uio->uio_resid > 0) {
bytelen = MIN(ext2fs_size(ip) - uio->uio_offset,
uio->uio_resid);
if (bytelen == 0)
break;
win = ubc_alloc(&vp->v_uobj, uio->uio_offset,
&bytelen, advice, UBC_READ);
error = uiomove(win, bytelen, uio);
flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0;
ubc_release(win, flags);
if (error)
break;
}
goto out;
}
for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
bytesinfile = ext2fs_size(ip) - uio->uio_offset;
if (bytesinfile <= 0)
break;
lbn = lblkno(fs, uio->uio_offset);
nextlbn = lbn + 1;
size = fs->e2fs_bsize;
blkoffset = blkoff(fs, uio->uio_offset);
xfersize = fs->e2fs_bsize - blkoffset;
if (uio->uio_resid < xfersize)
xfersize = uio->uio_resid;
if (bytesinfile < xfersize)
xfersize = bytesinfile;
if (lblktosize(fs, nextlbn) >= ext2fs_size(ip))
error = bread(vp, lbn, size, NOCRED, 0, &bp);
else {
int nextsize = fs->e2fs_bsize;
error = breadn(vp, lbn,
size, &nextlbn, &nextsize, 1, NOCRED, 0, &bp);
}
if (error)
break;
/*
* We should only get non-zero b_resid when an I/O error
* has occurred, which should cause us to break above.
* However, if the short read did not cause an error,
* then we want to ensure that we do not uiomove bad
* or uninitialized data.
*/
size -= bp->b_resid;
if (size < xfersize) {
if (size == 0)
break;
xfersize = size;
}
error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio);
if (error)
break;
brelse(bp, 0);
}
if (bp != NULL)
brelse(bp, 0);
out:
if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) {
ip->i_flag |= IN_ACCESS;
if ((ap->a_ioflag & IO_SYNC) == IO_SYNC)
error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT);
}
return (error);
}
/*
* Vnode op for writing.
*/
int
ext2fs_write(void *v)
{
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct vnode *vp;
struct uio *uio;
struct inode *ip;
struct m_ext2fs *fs;
struct buf *bp;
struct proc *p;
struct ufsmount *ump;
daddr_t lbn;
off_t osize;
int blkoffset, error, flags, ioflag, resid, xfersize;
vsize_t bytelen;
void *win;
off_t oldoff = 0; /* XXX */
bool async;
int extended = 0;
ioflag = ap->a_ioflag;
uio = ap->a_uio;
vp = ap->a_vp;
ip = VTOI(vp);
ump = ip->i_ump;
error = 0;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_WRITE)
panic("%s: mode", "ext2fs_write");
#endif
switch (vp->v_type) {
case VREG:
if (ioflag & IO_APPEND)
uio->uio_offset = ext2fs_size(ip);
if ((ip->i_e2fs_flags & EXT2_APPEND) &&
uio->uio_offset != ext2fs_size(ip))
return (EPERM);
/* FALLTHROUGH */
case VLNK:
break;
case VDIR:
if ((ioflag & IO_SYNC) == 0)
panic("%s: nonsync dir write", "ext2fs_write");
break;
default:
panic("%s: type", "ext2fs_write");
}
fs = ip->i_e2fs;
if (uio->uio_offset < 0 ||
(u_int64_t)uio->uio_offset + uio->uio_resid > ump->um_maxfilesize)
return (EFBIG);
/*
* Maybe this should be above the vnode op call, but so long as
* file servers have no limits, I don't think it matters.
*/
p = curproc;
if (vp->v_type == VREG && p &&
uio->uio_offset + uio->uio_resid >
p->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
mutex_enter(proc_lock);
psignal(p, SIGXFSZ);
mutex_exit(proc_lock);
return (EFBIG);
}
if (uio->uio_resid == 0)
return (0);
async = vp->v_mount->mnt_flag & MNT_ASYNC;
resid = uio->uio_resid;
osize = ext2fs_size(ip);
if (vp->v_type == VREG) {
while (uio->uio_resid > 0) {
oldoff = uio->uio_offset;
blkoffset = blkoff(fs, uio->uio_offset);
bytelen = MIN(fs->e2fs_bsize - blkoffset,
uio->uio_resid);
if (vp->v_size < oldoff + bytelen) {
uvm_vnp_setwritesize(vp, oldoff + bytelen);
}
error = ufs_balloc_range(vp, uio->uio_offset,
bytelen, ap->a_cred, 0);
if (error)
break;
win = ubc_alloc(&vp->v_uobj, uio->uio_offset,
&bytelen, UVM_ADV_NORMAL, UBC_WRITE);
error = uiomove(win, bytelen, uio);
flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0;
ubc_release(win, flags);
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);
extended = 1;
}
/*
* flush what we just wrote if necessary.
* XXXUBC simplistic async flushing.
*/
if (!async && oldoff >> 16 != uio->uio_offset >> 16) {
mutex_enter(&vp->v_interlock);
error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16,
(uio->uio_offset >> 16) << 16, PGO_CLEANIT);
}
}
if (error == 0 && ioflag & IO_SYNC) {
mutex_enter(&vp->v_interlock);
error = VOP_PUTPAGES(vp, trunc_page(oldoff),
round_page(blkroundup(fs, uio->uio_offset)),
PGO_CLEANIT | PGO_SYNCIO);
}
goto out;
}
flags = ioflag & IO_SYNC ? B_SYNC : 0;
for (error = 0; uio->uio_resid > 0;) {
lbn = lblkno(fs, uio->uio_offset);
blkoffset = blkoff(fs, uio->uio_offset);
xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid);
if (xfersize < fs->e2fs_bsize)
flags |= B_CLRBUF;
else
flags &= ~B_CLRBUF;
error = ext2fs_balloc(ip,
lbn, blkoffset + xfersize, ap->a_cred, &bp, flags);
if (error)
break;
if (ext2fs_size(ip) < uio->uio_offset + xfersize) {
error = ext2fs_setsize(ip, uio->uio_offset + xfersize);
if (error)
break;
}
error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio);
/*
* 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);
extended = 1;
}
if (ioflag & IO_SYNC)
(void)bwrite(bp);
else if (xfersize + blkoffset == fs->e2fs_bsize)
bawrite(bp);
else
bdwrite(bp);
if (error || xfersize == 0)
break;
}
/*
* If we successfully wrote any data, and we are not the superuser
* we clear the setuid and setgid bits as a precaution against
* tampering.
*/
out:
ip->i_flag |= IN_CHANGE | IN_UPDATE;
if (resid > uio->uio_resid && ap->a_cred &&
kauth_authorize_generic(ap->a_cred, KAUTH_GENERIC_ISSUSER, NULL))
ip->i_e2fs_mode &= ~(ISUID | ISGID);
if (resid > uio->uio_resid)
VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0));
if (error) {
(void) ext2fs_truncate(vp, osize, ioflag & IO_SYNC, ap->a_cred);
uio->uio_offset -= resid - uio->uio_resid;
uio->uio_resid = resid;
} else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC)
error = ext2fs_update(vp, NULL, NULL, UPDATE_WAIT);
KASSERT(vp->v_size == ext2fs_size(ip));
return (error);
}