/* $OpenBSD: vfs_vnops.c,v 1.53 2006/06/02 20:25:09 pedro Exp $ */ /* $NetBSD: vfs_vnops.c,v 1.20 1996/02/04 02:18:41 christos Exp $ */ /* * 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. 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 8.5 (Berkeley) 12/8/94 */ #include <sys/param.h> #include <sys/systm.h> #include <sys/kernel.h> #include <sys/malloc.h> #include <sys/file.h> #include <sys/stat.h> #include <sys/buf.h> #include <sys/proc.h> #include <sys/mount.h> #include <sys/namei.h> #include <sys/vnode.h> #include <sys/ioctl.h> #include <sys/tty.h> #include <sys/cdio.h> #include <sys/poll.h> #include <uvm/uvm_extern.h> #include <miscfs/specfs/specdev.h> int vn_read(struct file *, off_t *, struct uio *, struct ucred *); int vn_write(struct file *, off_t *, struct uio *, struct ucred *); int vn_poll(struct file *, int, struct proc *); int vn_kqfilter(struct file *, struct knote *); int vn_closefile(struct file *, struct proc *); int vn_ioctl(struct file *, u_long, caddr_t, struct proc *); struct fileops vnops = { vn_read, vn_write, vn_ioctl, vn_poll, vn_kqfilter, vn_statfile, vn_closefile }; /* * Common code for vnode open operations. * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. */ int vn_open(struct nameidata *ndp, int fmode, int cmode) { struct vnode *vp; struct proc *p = ndp->ni_cnd.cn_proc; struct ucred *cred = p->p_ucred; struct vattr va; int error; if ((fmode & (FREAD|FWRITE)) == 0) return (EINVAL); if ((fmode & (O_TRUNC | FWRITE)) == O_TRUNC) return (EINVAL); if (fmode & O_CREAT) { ndp->ni_cnd.cn_nameiop = CREATE; ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF; if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) ndp->ni_cnd.cn_flags |= FOLLOW; if ((error = namei(ndp)) != 0) return (error); if (ndp->ni_vp == NULL) { VATTR_NULL(&va); va.va_type = VREG; va.va_mode = cmode; VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE); error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, &ndp->ni_cnd, &va); if (error) return (error); 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 = ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF; if ((error = namei(ndp)) != 0) return (error); vp = ndp->ni_vp; } if (vp->v_type == VSOCK) { error = EOPNOTSUPP; goto bad; } if (vp->v_type == VLNK) { error = EMLINK; goto bad; } if ((fmode & O_CREAT) == 0) { if (fmode & FREAD) { if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0) goto bad; } if (fmode & FWRITE) { if (vp->v_type == VDIR) { error = EISDIR; goto bad; } if ((error = vn_writechk(vp)) != 0 || (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0) goto bad; } } if ((fmode & O_TRUNC) && vp->v_type == VREG) { VOP_UNLOCK(vp, 0, p); /* XXX */ VOP_LEASE(vp, p, cred, LEASE_WRITE); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); /* XXX */ VATTR_NULL(&va); va.va_size = 0; if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0) goto bad; } if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0) goto bad; if (vp->v_flag & VCLONED) { struct cloneinfo *cip = (struct cloneinfo *) vp->v_data; vp->v_flag &= ~VCLONED; ndp->ni_vp = cip->ci_vp; /* return cloned vnode */ vp->v_data = cip->ci_data; /* restore v_data */ VOP_UNLOCK(vp, 0, p); /* keep a reference */ vp = ndp->ni_vp; /* for the increment below */ free(cip, M_TEMP); } 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(struct vnode *vp) { /* * Disallow write attempts on read-only file systems; * unless the file is a socket or a block or character * device resident on the file system. */ if (vp->v_mount->mnt_flag & MNT_RDONLY) { switch (vp->v_type) { case VREG: case VDIR: case VLNK: return (EROFS); case VNON: case VCHR: case VSOCK: case VFIFO: case VBAD: case VBLK: break; } } /* * 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) && !uvm_vnp_uncache(vp)) return (ETXTBSY); return (0); } /* * Mark a vnode as being the text image of a running process. */ void vn_marktext(struct vnode *vp) { vp->v_flag |= VTEXT; } /* * Vnode close call */ int vn_close(struct vnode *vp, int flags, struct ucred *cred, struct proc *p) { int error; if (flags & FWRITE) vp->v_writecount--; vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); error = VOP_CLOSE(vp, flags, cred, p); vput(vp); return (error); } /* * Package up an I/O request on a vnode into a uio and do it. */ int vn_rdwr(enum uio_rw rw, struct vnode *vp, caddr_t base, int len, off_t offset, enum uio_seg segflg, int ioflg, struct ucred *cred, size_t *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. */ int vn_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) { struct vnode *vp = (struct vnode *)fp->f_data; int error = 0; size_t count; struct proc *p = uio->uio_procp; VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); uio->uio_offset = *poff; count = uio->uio_resid; if (vp->v_type != VDIR) error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, cred); *poff += count - uio->uio_resid; VOP_UNLOCK(vp, 0, p); return (error); } /* * File table vnode write routine. */ int vn_write(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred) { struct vnode *vp = (struct vnode *)fp->f_data; struct proc *p = uio->uio_procp; int error, ioflag = IO_UNIT; size_t count; if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) ioflag |= IO_APPEND; if (fp->f_flag & FNONBLOCK) ioflag |= IO_NDELAY; if ((fp->f_flag & FFSYNC) || (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) ioflag |= IO_SYNC; VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); uio->uio_offset = *poff; count = uio->uio_resid; error = VOP_WRITE(vp, uio, ioflag, cred); if (ioflag & IO_APPEND) *poff = uio->uio_offset; else *poff += count - uio->uio_resid; VOP_UNLOCK(vp, 0, p); return (error); } /* * File table wrapper for vn_stat */ int vn_statfile(struct file *fp, struct stat *sb, struct proc *p) { struct vnode *vp = (struct vnode *)fp->f_data; return vn_stat(vp, sb, p); } /* * vnode stat routine. */ int vn_stat(struct vnode *vp, struct stat *sb, struct proc *p) { struct vattr va; int error; mode_t mode; error = VOP_GETATTR(vp, &va, p->p_ucred, p); if (error) return (error); /* * Copy from vattr table */ sb->st_dev = va.va_fsid; sb->st_ino = va.va_fileid; mode = va.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 = va.va_nlink; sb->st_uid = va.va_uid; sb->st_gid = va.va_gid; sb->st_rdev = va.va_rdev; sb->st_size = va.va_size; sb->st_atimespec = va.va_atime; sb->st_mtimespec = va.va_mtime; sb->st_ctimespec = va.va_ctime; sb->st_blksize = va.va_blocksize; sb->st_flags = va.va_flags; sb->st_gen = va.va_gen; sb->st_blocks = va.va_bytes / S_BLKSIZE; return (0); } /* * File table vnode ioctl routine. */ int vn_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p) { 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 == FIBMAP) return VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p); if (com == FIONBIO || com == FIOASYNC) /* XXX */ return (0); /* XXX */ /* FALLTHROUGH */ 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) { 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. */ int vn_poll(struct file *fp, int events, struct proc *p) { return (VOP_POLL(((struct vnode *)fp->f_data), events, p)); } /* * Check that the vnode is still valid, and if so * acquire requested lock. */ int vn_lock(struct vnode *vp, int flags, struct proc *p) { int error; if ((flags & LK_RECURSEFAIL) == 0) flags |= LK_CANRECURSE; 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(vp, PINOD, "vn_lock", 0); error = ENOENT; } else { error = VOP_LOCK(vp, flags | LK_INTERLOCK, p); if (error == 0) return (error); } flags &= ~LK_INTERLOCK; } while (flags & LK_RETRY); return (error); } /* * File table vnode close routine. */ int vn_closefile(struct file *fp, struct proc *p) { return (vn_close(((struct vnode *)fp->f_data), fp->f_flag, fp->f_cred, p)); } int vn_kqfilter(struct file *fp, struct knote *kn) { return (VOP_KQFILTER(((struct vnode *)fp->f_data), kn)); } /* * Common code for vnode access operations. */ int vn_access(struct vnode *vp, int mode) { struct proc *p = curproc; int error; if ((error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p))) return (error); error = VOP_ACCESS(vp, mode, p->p_ucred, p); VOP_UNLOCK(vp, 0, p); return (error); } /* Check if a directory can be found inside another in the hierarchy */ int vn_isunder(struct vnode *lvp, struct vnode *rvp, struct proc *p) { int error; error = vfs_getcwd_common(lvp, rvp, NULL, NULL, MAXPATHLEN/2, 0, p); if (!error) return (1); return (0); }