/* * 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 * $FreeBSD: src/sys/kern/vfs_vnops.c,v 1.87.2.13 2002/12/29 18:19:53 dillon Exp $ * $DragonFly: src/sys/kern/vfs_vnops.c,v 1.21 2004/05/21 15:41:23 drhodus Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int vn_closefile (struct file *fp, struct thread *td); static int vn_ioctl (struct file *fp, u_long com, caddr_t data, struct thread *td); static int vn_read (struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td); static int vn_poll (struct file *fp, int events, struct ucred *cred, struct thread *td); static int vn_kqfilter (struct file *fp, struct knote *kn); static int vn_statfile (struct file *fp, struct stat *sb, struct thread *td); static int vn_write (struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td); struct fileops vnops = { NULL, /* port */ NULL, /* clone */ 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. * * Note that this does NOT free nameidata for the successful case, * due to the NDINIT being done elsewhere. */ int vn_open(ndp, fmode, cmode) struct nameidata *ndp; int fmode, cmode; { struct vnode *vp; struct thread *td = ndp->ni_cnd.cn_td; struct ucred *cred = ndp->ni_cnd.cn_cred; struct vattr vat; struct vattr *vap = &vat; int mode, error; KKASSERT(cred == td->td_proc->p_ucred); if (fmode & O_CREAT) { ndp->ni_cnd.cn_nameiop = NAMEI_CREATE; ndp->ni_cnd.cn_flags = CNP_LOCKPARENT | CNP_LOCKLEAF; if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) ndp->ni_cnd.cn_flags |= CNP_FOLLOW; bwillwrite(); 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, td, cred, LEASE_WRITE); error = VOP_CREATE(ndp->ni_dvp, NCPNULL, &ndp->ni_vp, &ndp->ni_cnd, vap); if (error) { NDFREE(ndp, NDF_ONLY_PNBUF); vput(ndp->ni_dvp); return (error); } vput(ndp->ni_dvp); ASSERT_VOP_UNLOCKED(ndp->ni_dvp, "create"); ASSERT_VOP_LOCKED(ndp->ni_vp, "create"); fmode &= ~O_TRUNC; vp = ndp->ni_vp; } else { 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 = NAMEI_LOOKUP; ndp->ni_cnd.cn_flags = CNP_LOCKLEAF | ((fmode & O_NOFOLLOW) ? 0 : CNP_FOLLOW); error = namei(ndp); if (error) return (error); vp = ndp->ni_vp; } if (vp->v_type == VLNK) { error = EMLINK; goto bad; } if (vp->v_type == VSOCK) { error = EOPNOTSUPP; goto bad; } if ((fmode & O_CREAT) == 0) { mode = 0; if (fmode & (FWRITE | O_TRUNC)) { if (vp->v_type == VDIR) { error = EISDIR; goto bad; } error = vn_writechk(vp); if (error) goto bad; mode |= VWRITE; } if (fmode & FREAD) mode |= VREAD; if (mode) { error = VOP_ACCESS(vp, mode, cred, td); if (error) goto bad; } } if (fmode & O_TRUNC) { VOP_UNLOCK(vp, NULL, 0, td); /* XXX */ VOP_LEASE(vp, td, cred, LEASE_WRITE); vn_lock(vp, NULL, LK_EXCLUSIVE | LK_RETRY, td); /* XXX */ VATTR_NULL(vap); vap->va_size = 0; error = VOP_SETATTR(vp, vap, cred, td); if (error) goto bad; } error = VOP_OPEN(vp, fmode, cred, td); if (error) goto bad; /* * Make sure that a VM object is created for VMIO support. */ if (vn_canvmio(vp) == TRUE) { if ((error = vfs_object_create(vp, td)) != 0) goto bad; } if (fmode & FWRITE) vp->v_writecount++; return (0); bad: NDFREE(ndp, NDF_ONLY_PNBUF); vput(vp); return (error); } /* * Check for write permissions on the specified vnode. * Prototype text segments cannot be written. */ int vn_writechk(vp) 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(struct vnode *vp, int flags, struct thread *td) { int error; if (flags & FWRITE) vp->v_writecount--; error = VOP_CLOSE(vp, flags, td); vrele(vp); return (error); } static __inline int sequential_heuristic(struct uio *uio, struct file *fp) { /* * Sequential heuristic - detect sequential operation */ if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || uio->uio_offset == fp->f_nextoff) { 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 += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE; if (tmpseq > IO_SEQMAX) tmpseq = IO_SEQMAX; fp->f_seqcount = tmpseq; return(fp->f_seqcount << IO_SEQSHIFT); } /* * Not sequential, quick draw-down of seqcount */ if (fp->f_seqcount > 1) fp->f_seqcount = 1; else fp->f_seqcount = 0; return(0); } /* * Package up an I/O request on a vnode into a uio and do it. * * We are going to assume the caller has done the appropriate * VOP_LEASE() call before calling vn_rdwr() */ int vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, td) 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 thread *td; { struct uio auio; struct iovec aiov; int error; if ((ioflg & IO_NODELOCKED) == 0) vn_lock(vp, NULL, LK_EXCLUSIVE | LK_RETRY, td); 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_td = td; 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, NULL, 0, td); return (error); } /* * Package up an I/O request on a vnode into a uio and do it. The I/O * request is split up into smaller chunks and we try to avoid saturating * the buffer cache while potentially holding a vnode locked, so we * check bwillwrite() before calling vn_rdwr(). We also call uio_yield() * to give other processes a chance to lock the vnode (either other processes * core'ing the same binary, or unrelated processes scanning the directory). */ int vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, td) 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 thread *td; { int error = 0; do { int chunk; /* * Force `offset' to a multiple of MAXBSIZE except possibly * for the first chunk, so that filesystems only need to * write full blocks except possibly for the first and last * chunks. */ chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; if (chunk > len) chunk = len; if (rw != UIO_READ && vp->v_type == VREG) bwillwrite(); error = vn_rdwr(rw, vp, base, chunk, offset, segflg, ioflg, cred, aresid, td); len -= chunk; /* aresid calc already includes length */ if (error) break; offset += chunk; base += chunk; uio_yield(); } while (len); if (aresid) *aresid += len; return (error); } /* * File table vnode read routine. */ static int vn_read(fp, uio, cred, flags, td) struct file *fp; struct uio *uio; struct ucred *cred; struct thread *td; int flags; { struct vnode *vp; int error, ioflag; KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td)); vp = (struct vnode *)fp->f_data; ioflag = 0; if (fp->f_flag & FNONBLOCK) ioflag |= IO_NDELAY; if (fp->f_flag & O_DIRECT) ioflag |= IO_DIRECT; VOP_LEASE(vp, td, cred, LEASE_READ); vn_lock(vp, NULL, LK_SHARED | LK_NOPAUSE | LK_RETRY, td); if ((flags & FOF_OFFSET) == 0) uio->uio_offset = fp->f_offset; ioflag |= sequential_heuristic(uio, fp); error = VOP_READ(vp, uio, ioflag, cred); if ((flags & FOF_OFFSET) == 0) fp->f_offset = uio->uio_offset; fp->f_nextoff = uio->uio_offset; VOP_UNLOCK(vp, NULL, 0, td); return (error); } /* * File table vnode write routine. */ static int vn_write(fp, uio, cred, flags, td) struct file *fp; struct uio *uio; struct ucred *cred; struct thread *td; int flags; { struct vnode *vp; int error, ioflag; KASSERT(uio->uio_td == td, ("uio_procp %p is not p %p", uio->uio_td, td)); vp = (struct vnode *)fp->f_data; if (vp->v_type == VREG) bwillwrite(); vp = (struct vnode *)fp->f_data; /* XXX needed? */ ioflag = IO_UNIT; 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 & O_DIRECT) ioflag |= IO_DIRECT; if ((fp->f_flag & O_FSYNC) || (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) ioflag |= IO_SYNC; VOP_LEASE(vp, td, cred, LEASE_WRITE); vn_lock(vp, NULL, LK_EXCLUSIVE | LK_RETRY, td); if ((flags & FOF_OFFSET) == 0) uio->uio_offset = fp->f_offset; ioflag |= sequential_heuristic(uio, fp); error = VOP_WRITE(vp, uio, ioflag, cred); if ((flags & FOF_OFFSET) == 0) fp->f_offset = uio->uio_offset; fp->f_nextoff = uio->uio_offset; VOP_UNLOCK(vp, NULL, 0, td); return (error); } /* * File table vnode stat routine. */ static int vn_statfile(struct file *fp, struct stat *sb, struct thread *td) { struct vnode *vp = (struct vnode *)fp->f_data; return vn_stat(vp, sb, td); } int vn_stat(struct vnode *vp, struct stat *sb, struct thread *td) { struct vattr vattr; struct vattr *vap; int error; u_short mode; vap = &vattr; error = VOP_GETATTR(vp, vap, td); if (error) return (error); /* * Zero the spare stat fields */ sb->st_lspare = 0; sb->st_qspare[0] = 0; sb->st_qspare[1] = 0; /* * Copy from vattr table */ if (vap->va_fsid != VNOVAL) sb->st_dev = vap->va_fsid; else sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; sb->st_ino = vap->va_fileid; mode = vap->va_mode; switch (vap->va_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; /* This is a cosmetic change, symlinks do not have a mode. */ if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) sb->st_mode &= ~ACCESSPERMS; /* 0000 */ else sb->st_mode |= ACCESSPERMS; /* 0777 */ 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; /* * According to www.opengroup.org, the meaning of st_blksize is * "a filesystem-specific preferred I/O block size for this * object. In some filesystem types, this may vary from file * to file" * Default to PAGE_SIZE after much discussion. */ if (vap->va_type == VREG) { sb->st_blksize = vap->va_blocksize; } else if (vn_isdisk(vp, NULL)) { /* * XXX this is broken. If the device is not yet open (aka * stat() call, aka v_rdev == NULL), how are we supposed * to get a valid block size out of it? */ dev_t dev; if ((dev = vp->v_rdev) == NULL) dev = udev2dev(vp->v_udev, vp->v_type == VBLK); sb->st_blksize = dev->si_bsize_best; if (sb->st_blksize < dev->si_bsize_phys) sb->st_blksize = dev->si_bsize_phys; if (sb->st_blksize < BLKDEV_IOSIZE) sb->st_blksize = BLKDEV_IOSIZE; } else { sb->st_blksize = PAGE_SIZE; } sb->st_flags = vap->va_flags; if (suser(td)) 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(struct file *fp, u_long com, caddr_t data, struct thread *td) { struct vnode *vp = ((struct vnode *)fp->f_data); struct ucred *ucred; struct vattr vattr; int error; KKASSERT(td->td_proc != NULL); ucred = td->td_proc->p_ucred; switch (vp->v_type) { case VREG: case VDIR: if (com == FIONREAD) { error = VOP_GETATTR(vp, &vattr, td); 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: #if 0 return (ENOTTY); #endif case VFIFO: case VCHR: case VBLK: if (com == FIODTYPE) { if (vp->v_type != VCHR && vp->v_type != VBLK) return (ENOTTY); *(int *)data = dev_dflags(vp->v_rdev) & D_TYPEMASK; return (0); } error = VOP_IOCTL(vp, com, data, fp->f_flag, ucred, td); if (error == 0 && com == TIOCSCTTY) { struct session *sess = td->td_proc->p_session; /* Do nothing if reassigning same control tty */ if (sess->s_ttyvp == vp) return (0); /* Get rid of reference to old control tty */ if (sess->s_ttyvp) vrele(sess->s_ttyvp); sess->s_ttyvp = vp; vref(vp); } return (error); } } /* * File table vnode poll routine. */ static int vn_poll(struct file *fp, int events, struct ucred *cred, struct thread *td) { return (VOP_POLL(((struct vnode *)fp->f_data), events, cred, td)); } /* * Check that the vnode is still valid, and if so * acquire requested lock. */ int #ifndef DEBUG_LOCKS vn_lock(struct vnode *vp, lwkt_tokref_t vlock, int flags, struct thread *td) #else debug_vn_lock(struct vnode *vp, lwkt_tokref_t vlock, int flags, struct thread *td, const char *filename, int line) #endif { int error; lwkt_tokref vvlock; do { if ((flags & LK_INTERLOCK) == 0) { lwkt_gettoken(&vvlock, vp->v_interlock); vlock = &vvlock; } if ((vp->v_flag & VXLOCK) && vp->v_vxthread != curthread) { vp->v_flag |= VXWANT; lwkt_reltoken(vlock); tsleep((caddr_t)vp, 0, "vn_lock", 0); error = ENOENT; } else { #if 0 /* this can now occur in normal operation */ if (vp->v_vxthread != NULL) log(LOG_INFO, "VXLOCK interlock avoided in vn_lock\n"); #endif #ifdef DEBUG_LOCKS vp->filename = filename; vp->line = line; #endif error = VOP_LOCK(vp, vlock, flags | LK_NOPAUSE | LK_INTERLOCK, td); if (error == 0) return (0); } flags &= ~LK_INTERLOCK; } while (flags & LK_RETRY); return (error); } /* * File table vnode close routine. */ static int vn_closefile(struct file *fp, struct thread *td) { int err; fp->f_ops = &badfileops; err = vn_close(((struct vnode *)fp->f_data), fp->f_flag, td); return(err); } static int vn_kqfilter(struct file *fp, struct knote *kn) { return (VOP_KQFILTER(((struct vnode *)fp->f_data), kn)); }