Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
NetBSD/sys/ufs/ufs/ufs_readwrite.c

301 lines
8.2 KiB
C
Raw Blame History

/* $NetBSD: ufs_readwrite.c,v 1.6 1995/03/24 15:33:31 cgd 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. 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
*/
#ifdef LFS_READWRITE
#define BLKSIZE(a, b, c) blksize(a)
#define FS struct lfs
#define I_FS i_lfs
#define READ lfs_read
#define READ_S "lfs_read"
#define WRITE lfs_write
#define WRITE_S "lfs_write"
#define fs_bsize lfs_bsize
#define fs_maxfilesize lfs_maxfilesize
#else
#define BLKSIZE(a, b, c) blksize(a, b, c)
#define FS struct fs
#define I_FS i_fs
#define READ ffs_read
#define READ_S "ffs_read"
#define WRITE ffs_write
#define WRITE_S "ffs_write"
#endif
/*
* Vnode op for reading.
*/
/* ARGSUSED */
READ(ap)
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
register struct vnode *vp;
register struct inode *ip;
register struct uio *uio;
register FS *fs;
struct buf *bp;
daddr_t lbn, nextlbn;
off_t bytesinfile;
long size, xfersize, blkoffset;
int error;
u_short mode;
vp = ap->a_vp;
ip = VTOI(vp);
mode = ip->i_mode;
uio = ap->a_uio;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("%s: mode", READ_S);
if (vp->v_type == VLNK) {
if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen ||
(vp->v_mount->mnt_maxsymlinklen == 0 &&
ip->i_din.di_blocks == 0))
panic("%s: short symlink", READ_S);
} else if (vp->v_type != VREG && vp->v_type != VDIR)
panic("%s: type %d", READ_S, vp->v_type);
#endif
fs = ip->I_FS;
if ((u_int64_t)uio->uio_offset > fs->fs_maxfilesize)
return (EFBIG);
for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
break;
lbn = lblkno(fs, uio->uio_offset);
nextlbn = lbn + 1;
size = BLKSIZE(fs, ip, lbn);
blkoffset = blkoff(fs, uio->uio_offset);
xfersize = fs->fs_bsize - blkoffset;
if (uio->uio_resid < xfersize)
xfersize = uio->uio_resid;
if (bytesinfile < xfersize)
xfersize = bytesinfile;
#ifdef LFS_READWRITE
(void)lfs_check(vp, lbn);
error = cluster_read(vp, ip->i_size, lbn, size, NOCRED, &bp);
#else
if (lblktosize(fs, nextlbn) >= ip->i_size)
error = bread(vp, lbn, size, NOCRED, &bp);
else if (doclusterread)
error = cluster_read(vp,
ip->i_size, lbn, size, NOCRED, &bp);
else if (lbn - 1 == vp->v_lastr) {
int nextsize = BLKSIZE(fs, ip, nextlbn);
error = breadn(vp, lbn,
size, &nextlbn, &nextsize, 1, NOCRED, &bp);
} else
error = bread(vp, lbn, size, NOCRED, &bp);
#endif
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;
}
if (error =
uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio))
break;
if (S_ISREG(mode) && (xfersize + blkoffset == fs->fs_bsize ||
uio->uio_offset == ip->i_size))
bp->b_flags |= B_AGE;
brelse(bp);
}
if (bp != NULL)
brelse(bp);
ip->i_flag |= IN_ACCESS;
return (error);
}
/*
* Vnode op for writing.
*/
WRITE(ap)
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
register struct vnode *vp;
register struct uio *uio;
register struct inode *ip;
register FS *fs;
struct buf *bp;
struct proc *p;
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", WRITE_S);
#endif
switch (vp->v_type) {
case VREG:
if (ioflag & IO_APPEND)
uio->uio_offset = ip->i_size;
if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
return (EPERM);
/* FALLTHROUGH */
case VLNK:
break;
case VDIR:
if ((ioflag & IO_SYNC) == 0)
panic("%s: nonsync dir write", WRITE_S);
break;
default:
panic("%s: type", WRITE_S);
}
fs = ip->I_FS;
if (uio->uio_offset < 0 ||
(u_int64_t)uio->uio_offset + uio->uio_resid > fs->fs_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 = 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_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->fs_bsize - blkoffset;
if (uio->uio_resid < xfersize)
xfersize = uio->uio_resid;
#ifdef LFS_READWRITE
(void)lfs_check(vp, lbn);
error = lfs_balloc(vp, xfersize, lbn, &bp);
#else
if (fs->fs_bsize > xfersize)
flags |= B_CLRBUF;
else
flags &= ~B_CLRBUF;
error = ffs_balloc(ip,
lbn, blkoffset + xfersize, ap->a_cred, &bp, flags);
#endif
if (error)
break;
if (uio->uio_offset + xfersize > ip->i_size) {
ip->i_size = uio->uio_offset + xfersize;
vnode_pager_setsize(vp, (u_long)ip->i_size);
}
(void)vnode_pager_uncache(vp);
size = BLKSIZE(fs, ip, lbn) - bp->b_resid;
if (size < xfersize)
xfersize = size;
error =
uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
#ifdef LFS_READWRITE
(void)VOP_BWRITE(bp);
#else
if (ioflag & IO_SYNC)
(void)bwrite(bp);
else if (xfersize + blkoffset == fs->fs_bsize)
if (doclusterwrite)
cluster_write(bp, ip->i_size);
else {
bp->b_flags |= B_AGE;
bawrite(bp);
}
else
bdwrite(bp);
#endif
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_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))
error = VOP_UPDATE(vp, (struct timeval *)&time,
(struct timeval *)&time, 1);
return (error);
}
Reference in New Issue View Git Blame Copy Permalink