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NetBSD/sys/ufs/ext2fs/ext2fs_readwrite.c

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/* $NetBSD: ext2fs_readwrite.c,v 1.13 2000/06/28 14:16:38 mrg Exp $ */
/*-
* Copyright (c) 1997 Manuel Bouyer.
* 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. 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.
*
* @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94
* Modified for ext2fs by Manuel Bouyer.
*/
#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/conf.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/signalvar.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.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(v)
void *v;
{
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap = v;
struct vnode *vp;
struct inode *ip;
struct uio *uio;
struct m_ext2fs *fs;
struct buf *bp;
ufs_daddr_t lbn, nextlbn;
off_t bytesinfile;
long size, xfersize, blkoffset;
int error;
vp = ap->a_vp;
ip = VTOI(vp);
uio = ap->a_uio;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("%s: mode", "ext2fs_read");
if (vp->v_type == VLNK) {
if ((int)ip->i_e2fs_size < vp->v_mount->mnt_maxsymlinklen ||
(vp->v_mount->mnt_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 >
((u_int64_t)0x80000000 * fs->e2fs_bsize - 1))
return (EFBIG);
if (uio->uio_resid == 0)
return (0);
for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 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) >= ip->i_e2fs_size)
error = bread(vp, lbn, size, NOCRED, &bp);
else if (doclusterread)
error = cluster_read(vp,
ip->i_e2fs_size, lbn, size, NOCRED, &bp);
else if (lbn - 1 == vp->v_lastr) {
int nextsize = fs->e2fs_bsize;
error = breadn(vp, lbn,
size, &nextlbn, &nextsize, 1, NOCRED, &bp);
} else
error = bread(vp, lbn, size, NOCRED, &bp);
if (error)
break;
vp->v_lastr = lbn;
/*
* 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, (int)xfersize,
uio);
if (error)
break;
brelse(bp);
}
if (bp != NULL)
brelse(bp);
if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) {
ip->i_flag |= IN_ACCESS;
if ((ap->a_ioflag & IO_SYNC) == IO_SYNC)
error = VOP_UPDATE(vp, NULL, NULL, UPDATE_WAIT);
}
return (error);
}
/*
* Vnode op for writing.
*/
int
ext2fs_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 vnode *vp;
struct uio *uio;
struct inode *ip;
struct m_ext2fs *fs;
struct buf *bp;
struct proc *p;
ufs_daddr_t lbn;
off_t osize;
int blkoffset, error, flags, ioflag, resid, size, xfersize;
ioflag = ap->a_ioflag;
uio = ap->a_uio;
vp = ap->a_vp;
ip = VTOI(vp);
#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 = ip->i_e2fs_size;
if ((ip->i_e2fs_flags & EXT2_APPEND) &&
uio->uio_offset != ip->i_e2fs_size)
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 >
((u_int64_t)0x80000000 * fs->e2fs_bsize - 1))
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 = uio->uio_procp;
if (vp->v_type == VREG && p &&
uio->uio_offset + uio->uio_resid >
p->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
psignal(p, SIGXFSZ);
return (EFBIG);
}
resid = uio->uio_resid;
osize = ip->i_e2fs_size;
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 = fs->e2fs_bsize - blkoffset;
if (uio->uio_resid < xfersize)
xfersize = uio->uio_resid;
if (fs->e2fs_bsize > xfersize)
flags |= B_CLRBUF;
else
flags &= ~B_CLRBUF;
error = ext2fs_balloc(ip,
lbn, blkoffset + xfersize, ap->a_cred, &bp, flags);
if (error)
break;
if (uio->uio_offset + xfersize > ip->i_e2fs_size) {
ip->i_e2fs_size = uio->uio_offset + xfersize;
uvm_vnp_setsize(vp, ip->i_e2fs_size);
}
(void)uvm_vnp_uncache(vp);
size = fs->e2fs_bsize - bp->b_resid;
if (size < xfersize)
xfersize = size;
error =
uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
if (ioflag & IO_SYNC)
(void)bwrite(bp);
else if (xfersize + blkoffset == fs->e2fs_bsize)
if (doclusterwrite)
cluster_write(bp, ip->i_e2fs_size);
else
bawrite(bp);
else
bdwrite(bp);
if (error || xfersize == 0)
break;
ip->i_flag |= IN_CHANGE | IN_UPDATE;
}
/*
* If we successfully wrote any data, and we are not the superuser
* we clear the setuid and setgid bits as a precaution against
* tampering.
*/
if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
ip->i_e2fs_mode &= ~(ISUID | ISGID);
if (error) {
if (ioflag & IO_UNIT) {
(void)VOP_TRUNCATE(vp, osize,
ioflag & IO_SYNC, ap->a_cred, uio->uio_procp);
uio->uio_offset -= resid - uio->uio_resid;
uio->uio_resid = resid;
}
} else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC)
error = VOP_UPDATE(vp, NULL, NULL, UPDATE_WAIT);
return (error);
}
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