/* $NetBSD: ext2fs_readwrite.c,v 1.16 2001/02/27 04:37:47 chs 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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_ci, ip->i_e2fs_size, lbn, size, NOCRED, &bp); else if (lbn - 1 == ip->i_ci.ci_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; ip->i_ci.ci_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, 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; } 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 /* * If writing 0 bytes, succeed and do not change * update time or file offset (standards compliance) */ if (uio->uio_resid == 0) return (0); 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_buf_alloc(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); } 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_ci, 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)ext2fs_truncate(ip, 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)) { error = ext2fs_update(ip, NULL, NULL, 1); } return (error); }