/* * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * 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. * * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 * $Id: vfs_vnops.c,v 1.41 1997/11/07 08:53:11 phk Exp $ */ #include #include #include #include #include #include #include #include #include #include #include static int vn_closefile __P((struct file *fp, struct proc *p)); static int vn_ioctl __P((struct file *fp, int com, caddr_t data, struct proc *p)); static int vn_read __P((struct file *fp, struct uio *uio, struct ucred *cred)); static int vn_poll __P((struct file *fp, int events, struct ucred *cred, struct proc *p)); static int vn_write __P((struct file *fp, struct uio *uio, struct ucred *cred)); struct fileops vnops = { vn_read, vn_write, vn_ioctl, vn_poll, vn_closefile }; /* * Common code for vnode open operations. * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. */ int vn_open(ndp, fmode, cmode) register struct nameidata *ndp; int fmode, cmode; { register struct vnode *vp; register struct proc *p = ndp->ni_cnd.cn_proc; register struct ucred *cred = p->p_ucred; struct vattr vat; struct vattr *vap = &vat; int error; if (fmode & O_CREAT) { ndp->ni_cnd.cn_nameiop = CREATE; ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; if ((fmode & O_EXCL) == 0) ndp->ni_cnd.cn_flags |= FOLLOW; error = namei(ndp); if (error) return (error); if (ndp->ni_vp == NULL) { VATTR_NULL(vap); vap->va_type = VREG; vap->va_mode = cmode; if (fmode & O_EXCL) vap->va_vaflags |= VA_EXCLUSIVE; VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); if (error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, &ndp->ni_cnd, vap)) return (error); ASSERT_VOP_UNLOCKED(ndp->ni_dvp, "create"); ASSERT_VOP_LOCKED(ndp->ni_vp, "create"); fmode &= ~O_TRUNC; vp = ndp->ni_vp; } else { VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd); if (ndp->ni_dvp == ndp->ni_vp) vrele(ndp->ni_dvp); else vput(ndp->ni_dvp); ndp->ni_dvp = NULL; vp = ndp->ni_vp; if (fmode & O_EXCL) { error = EEXIST; goto bad; } fmode &= ~O_CREAT; } } else { ndp->ni_cnd.cn_nameiop = LOOKUP; ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF; error = namei(ndp); if (error) return (error); vp = ndp->ni_vp; } if (vp->v_type == VSOCK) { error = EOPNOTSUPP; goto bad; } if ((fmode & O_CREAT) == 0) { if (fmode & FREAD) { error = VOP_ACCESS(vp, VREAD, cred, p); if (error) goto bad; } if (fmode & (FWRITE | O_TRUNC)) { if (vp->v_type == VDIR) { error = EISDIR; goto bad; } error = vn_writechk(vp); if (error) goto bad; error = VOP_ACCESS(vp, VWRITE, cred, p); if (error) goto bad; } } if (fmode & O_TRUNC) { VOP_UNLOCK(vp, 0, p); /* XXX */ VOP_LEASE(vp, p, cred, LEASE_WRITE); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); /* XXX */ VATTR_NULL(vap); vap->va_size = 0; error = VOP_SETATTR(vp, vap, cred, p); if (error) goto bad; } error = VOP_OPEN(vp, fmode, cred, p); if (error) goto bad; /* * Make sure that a VM object is created for VMIO support. */ if (vp->v_type == VREG) { if ((error = vfs_object_create(vp, p, cred, 1)) != 0) goto bad; } if (fmode & FWRITE) vp->v_writecount++; return (0); bad: vput(vp); return (error); } /* * Check for write permissions on the specified vnode. * Prototype text segments cannot be written. */ int vn_writechk(vp) register struct vnode *vp; { /* * If there's shared text associated with * the vnode, try to free it up once. If * we fail, we can't allow writing. */ if (vp->v_flag & VTEXT) return (ETXTBSY); return (0); } /* * Vnode close call */ int vn_close(vp, flags, cred, p) register struct vnode *vp; int flags; struct ucred *cred; struct proc *p; { int error; if (flags & FWRITE) vp->v_writecount--; error = VOP_CLOSE(vp, flags, cred, p); vrele(vp); return (error); } /* * Package up an I/O request on a vnode into a uio and do it. */ int vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p) enum uio_rw rw; struct vnode *vp; caddr_t base; int len; off_t offset; enum uio_seg segflg; int ioflg; struct ucred *cred; int *aresid; struct proc *p; { struct uio auio; struct iovec aiov; int error; if ((ioflg & IO_NODELOCKED) == 0) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); auio.uio_iov = &aiov; auio.uio_iovcnt = 1; aiov.iov_base = base; aiov.iov_len = len; auio.uio_resid = len; auio.uio_offset = offset; auio.uio_segflg = segflg; auio.uio_rw = rw; auio.uio_procp = p; if (rw == UIO_READ) { error = VOP_READ(vp, &auio, ioflg, cred); } else { error = VOP_WRITE(vp, &auio, ioflg, cred); } if (aresid) *aresid = auio.uio_resid; else if (auio.uio_resid && error == 0) error = EIO; if ((ioflg & IO_NODELOCKED) == 0) VOP_UNLOCK(vp, 0, p); return (error); } /* * File table vnode read routine. */ static int vn_read(fp, uio, cred) struct file *fp; struct uio *uio; struct ucred *cred; { struct vnode *vp = (struct vnode *)fp->f_data; struct proc *p = uio->uio_procp; int count, error; int flag; VOP_LEASE(vp, p, cred, LEASE_READ); vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, p); if (uio->uio_offset == -1) uio->uio_offset = fp->f_offset; count = uio->uio_resid; flag = 0; if (fp->f_flag & FNONBLOCK) flag |= IO_NDELAY; /* * Sequential read heuristic. * If we have been doing sequential input, * a rewind operation doesn't turn off * sequential input mode. */ if (((fp->f_offset == 0) && (fp->f_seqcount > 0)) || (fp->f_offset == fp->f_nextread)) { int tmpseq = fp->f_seqcount; /* * XXX we assume that the filesystem block size is * the default. Not true, but still gives us a pretty * good indicator of how sequential the read operations * are. */ tmpseq += ((count + BKVASIZE - 1) / BKVASIZE); if (tmpseq >= 127) tmpseq = 127; fp->f_seqcount = tmpseq; flag |= (fp->f_seqcount << 16); } else { if (fp->f_seqcount > 1) fp->f_seqcount = 1; else fp->f_seqcount = 0; } error = VOP_READ(vp, uio, flag, cred); fp->f_offset += count - uio->uio_resid; fp->f_nextread = fp->f_offset; VOP_UNLOCK(vp, 0, p); return (error); } /* * File table vnode write routine. */ static int vn_write(fp, uio, cred) struct file *fp; struct uio *uio; struct ucred *cred; { struct vnode *vp = (struct vnode *)fp->f_data; struct proc *p = uio->uio_procp; int count, error, ioflag = IO_UNIT; if (uio->uio_offset == -1 && vp->v_type == VREG && (fp->f_flag & O_APPEND)) ioflag |= IO_APPEND; if (fp->f_flag & FNONBLOCK) ioflag |= IO_NDELAY; if ((fp->f_flag & O_FSYNC) || (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) ioflag |= IO_SYNC; VOP_LEASE(vp, p, cred, LEASE_WRITE); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); uio->uio_offset = fp->f_offset; count = uio->uio_resid; error = VOP_WRITE(vp, uio, ioflag, cred); if (ioflag & IO_APPEND) fp->f_offset = uio->uio_offset; else fp->f_offset += count - uio->uio_resid; VOP_UNLOCK(vp, 0, p); return (error); } /* * File table vnode stat routine. */ int vn_stat(vp, sb, p) struct vnode *vp; register struct stat *sb; struct proc *p; { struct vattr vattr; register struct vattr *vap; int error; u_short mode; vap = &vattr; error = VOP_GETATTR(vp, vap, p->p_ucred, p); if (error) return (error); /* * Copy from vattr table */ sb->st_dev = vap->va_fsid; sb->st_ino = vap->va_fileid; mode = vap->va_mode; switch (vp->v_type) { case VREG: mode |= S_IFREG; break; case VDIR: mode |= S_IFDIR; break; case VBLK: mode |= S_IFBLK; break; case VCHR: mode |= S_IFCHR; break; case VLNK: mode |= S_IFLNK; break; case VSOCK: mode |= S_IFSOCK; break; case VFIFO: mode |= S_IFIFO; break; default: return (EBADF); }; sb->st_mode = mode; sb->st_nlink = vap->va_nlink; sb->st_uid = vap->va_uid; sb->st_gid = vap->va_gid; sb->st_rdev = vap->va_rdev; sb->st_size = vap->va_size; sb->st_atimespec = vap->va_atime; sb->st_mtimespec = vap->va_mtime; sb->st_ctimespec = vap->va_ctime; sb->st_blksize = vap->va_blocksize; sb->st_flags = vap->va_flags; if (p->p_ucred->cr_uid != 0) sb->st_gen = 0; else sb->st_gen = vap->va_gen; #if (S_BLKSIZE == 512) /* Optimize this case */ sb->st_blocks = vap->va_bytes >> 9; #else sb->st_blocks = vap->va_bytes / S_BLKSIZE; #endif return (0); } /* * File table vnode ioctl routine. */ static int vn_ioctl(fp, com, data, p) struct file *fp; int com; caddr_t data; struct proc *p; { register struct vnode *vp = ((struct vnode *)fp->f_data); struct vattr vattr; int error; switch (vp->v_type) { case VREG: case VDIR: if (com == FIONREAD) { error = VOP_GETATTR(vp, &vattr, p->p_ucred, p); if (error) return (error); *(int *)data = vattr.va_size - fp->f_offset; return (0); } if (com == FIONBIO || com == FIOASYNC) /* XXX */ return (0); /* XXX */ /* fall into ... */ default: return (ENOTTY); case VFIFO: case VCHR: case VBLK: error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); if (error == 0 && com == TIOCSCTTY) { /* Do nothing if reassigning same control tty */ if (p->p_session->s_ttyvp == vp) return (0); /* Get rid of reference to old control tty */ if (p->p_session->s_ttyvp) vrele(p->p_session->s_ttyvp); p->p_session->s_ttyvp = vp; VREF(vp); } return (error); } } /* * File table vnode poll routine. */ static int vn_poll(fp, events, cred, p) struct file *fp; int events; struct ucred *cred; struct proc *p; { return (VOP_POLL(((struct vnode *)fp->f_data), events, cred, p)); } /* * Check that the vnode is still valid, and if so * acquire requested lock. */ int vn_lock(vp, flags, p) struct vnode *vp; int flags; struct proc *p; { int error; do { if ((flags & LK_INTERLOCK) == 0) simple_lock(&vp->v_interlock); if (vp->v_flag & VXLOCK) { vp->v_flag |= VXWANT; simple_unlock(&vp->v_interlock); tsleep((caddr_t)vp, PINOD, "vn_lock", 0); error = ENOENT; } else { error = VOP_LOCK(vp, flags | LK_NOPAUSE | LK_INTERLOCK, p); if (error == 0) return (error); } flags &= ~LK_INTERLOCK; } while (flags & LK_RETRY); return (error); } /* * File table vnode close routine. */ static int vn_closefile(fp, p) struct file *fp; struct proc *p; { return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, fp->f_cred, p)); }