/* $NetBSD: ext2fs_readwrite.c,v 1.64 2013/06/23 07:28:37 dholland 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. * * 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 __KERNEL_RCSID(0, "$NetBSD: ext2fs_readwrite.c,v 1.64 2013/06/23 07:28:37 dholland Exp $"); #include #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(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; vsize_t bytelen; daddr_t lbn, nextlbn; off_t bytesinfile; long size, xfersize, blkoffset; int error; 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 && ext2fs_nblock(ip) == 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 ((uint64_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; error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice, UBC_READ | UBC_PARTIALOK | UBC_UNMAP_FLAG(vp)); 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 = ext2_lblkno(fs, uio->uio_offset); nextlbn = lbn + 1; size = fs->e2fs_bsize; blkoffset = ext2_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 (ext2_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 ufsmount *ump; daddr_t lbn; off_t osize; int blkoffset, error, flags, ioflag, resid, xfersize; vsize_t bytelen; off_t oldoff = 0; /* XXX */ bool async; int extended = 0; int advice; ioflag = ap->a_ioflag; advice = IO_ADV_DECODE(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 || (uint64_t)uio->uio_offset + uio->uio_resid > ump->um_maxfilesize) 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 = ext2_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; error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice, UBC_WRITE | UBC_UNMAP_FLAG(vp)); 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 | PGO_LAZY); } } if (error == 0 && ioflag & IO_SYNC) { mutex_enter(vp->v_interlock); error = VOP_PUTPAGES(vp, trunc_page(oldoff), round_page(ext2_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 = ext2_lblkno(fs, uio->uio_offset); blkoffset = ext2_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 (vp->v_mount->mnt_flag & MNT_RELATIME) ip->i_flag |= IN_ACCESS; if (resid > uio->uio_resid && ap->a_cred) { if (ip->i_e2fs_mode & ISUID) { if (kauth_authorize_vnode(ap->a_cred, KAUTH_VNODE_RETAIN_SUID, vp, NULL, EPERM) != 0) ip->i_e2fs_mode &= ISUID; } if (ip->i_e2fs_mode & ISGID) { if (kauth_authorize_vnode(ap->a_cred, KAUTH_VNODE_RETAIN_SGID, vp, NULL, EPERM) != 0) ip->i_e2fs_mode &= ~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); }