2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94
39 * $FreeBSD: src/sys/kern/vfs_vnops.c,v 1.87.2.13 2002/12/29 18:19:53 dillon Exp $
40 * $DragonFly: src/sys/kern/vfs_vnops.c,v 1.26 2004/11/22 00:53:54 dillon Exp $
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/fcntl.h>
49 #include <sys/mount.h>
50 #include <sys/nlookup.h>
51 #include <sys/vnode.h>
53 #include <sys/filio.h>
54 #include <sys/ttycom.h>
56 #include <sys/syslog.h>
58 static int vn_closefile (struct file *fp, struct thread *td);
59 static int vn_ioctl (struct file *fp, u_long com, caddr_t data,
61 static int vn_read (struct file *fp, struct uio *uio,
62 struct ucred *cred, int flags, struct thread *td);
63 static int svn_read (struct file *fp, struct uio *uio,
64 struct ucred *cred, int flags, struct thread *td);
65 static int vn_poll (struct file *fp, int events, struct ucred *cred,
67 static int vn_kqfilter (struct file *fp, struct knote *kn);
68 static int vn_statfile (struct file *fp, struct stat *sb, struct thread *td);
69 static int vn_write (struct file *fp, struct uio *uio,
70 struct ucred *cred, int flags, struct thread *td);
71 static int svn_write (struct file *fp, struct uio *uio,
72 struct ucred *cred, int flags, struct thread *td);
74 struct fileops vnode_fileops = {
77 vn_read, vn_write, vn_ioctl, vn_poll, vn_kqfilter,
78 vn_statfile, vn_closefile
81 struct fileops specvnode_fileops = {
84 svn_read, svn_write, vn_ioctl, vn_poll, vn_kqfilter,
85 vn_statfile, vn_closefile
89 * Shortcut the device read/write. This avoids a lot of vnode junk.
90 * Basically the specfs vnops for read and write take the locked vnode,
91 * unlock it (because we can't hold the vnode locked while reading or writing
92 * a device which may block indefinitely), issues the device operation, then
93 * relock the vnode before returning, plus other junk. This bypasses all
94 * of that and just does the device operation.
97 vn_setspecops(struct file *fp)
99 if (vfs_fastdev && fp->f_ops == &vnode_fileops) {
100 fp->f_ops = &specvnode_fileops;
105 * Common code for vnode open operations. Check permissions, and call
106 * the VOP_NOPEN or VOP_NCREATE routine.
108 * The caller is responsible for setting up nd with nlookup_init() and
109 * for cleaning it up with nlookup_done(), whether we return an error
112 * On success nd->nl_open_vp will hold a referenced and, if requested,
113 * locked vnode. A locked vnode is requested via NLC_LOCKVP. If fp
114 * is non-NULL the vnode will be installed in the file pointer.
116 * NOTE: The vnode is referenced just once on return whether or not it
117 * is also installed in the file pointer.
120 vn_open(struct nlookupdata *nd, struct file *fp, int fmode, int cmode)
123 struct thread *td = nd->nl_td;
124 struct ucred *cred = nd->nl_cred;
126 struct vattr *vap = &vat;
127 struct namecache *ncp;
131 * Lookup the path and create or obtain the vnode. After a
132 * successful lookup a locked nd->nl_ncp will be returned.
134 * The result of this section should be a locked vnode.
136 * XXX with only a little work we should be able to avoid locking
137 * the vnode if FWRITE, O_CREAT, and O_TRUNC are *not* set.
139 if (fmode & O_CREAT) {
141 * CONDITIONAL CREATE FILE CASE
143 * Setting NLC_CREATE causes a negative hit to store
144 * the negative hit ncp and not return an error. Then
145 * nc_error or nc_vp may be checked to see if the ncp
146 * represents a negative hit. NLC_CREATE also requires
147 * write permission on the governing directory or EPERM
150 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
151 nd->nl_flags |= NLC_FOLLOW;
152 nd->nl_flags |= NLC_CREATE;
160 if (ncp->nc_vp == NULL) {
163 vap->va_mode = cmode;
165 vap->va_vaflags |= VA_EXCLUSIVE;
166 error = VOP_NCREATE(ncp, &vp, nd->nl_cred, vap);
170 ASSERT_VOP_LOCKED(vp, "create");
171 /* locked vnode is returned */
173 if (fmode & O_EXCL) {
176 error = cache_vget(ncp, cred,
185 * NORMAL OPEN FILE CASE
193 error = cache_vget(ncp, cred, LK_EXCLUSIVE, &vp);
199 * We have a locked vnode now.
201 if (vp->v_type == VLNK) {
205 if (vp->v_type == VSOCK) {
209 if ((fmode & O_CREAT) == 0) {
211 if (fmode & (FWRITE | O_TRUNC)) {
212 if (vp->v_type == VDIR) {
216 error = vn_writechk(vp);
224 error = VOP_ACCESS(vp, mode, cred, td);
229 if (fmode & O_TRUNC) {
230 VOP_UNLOCK(vp, 0, td); /* XXX */
231 VOP_LEASE(vp, td, cred, LEASE_WRITE);
232 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); /* XXX */
235 error = VOP_SETATTR(vp, vap, cred, td);
241 * Setup the fp so VOP_OPEN can override it. No descriptor has been
242 * associated with the fp yet so we own it clean. f_data will inherit
243 * our vp reference as long as we do not shift f_ops to &badfileops.
244 * f_ncp inherits nl_ncp .
247 fp->f_data = (caddr_t)vp;
248 fp->f_flag = fmode & FMASK;
249 fp->f_ops = &vnode_fileops;
250 fp->f_type = (vp->v_type == VFIFO ? DTYPE_FIFO : DTYPE_VNODE);
251 if (vp->v_type == VDIR) {
252 fp->f_ncp = nd->nl_ncp;
254 cache_unlock(fp->f_ncp);
259 * Get rid of nl_ncp. vn_open does not return it (it returns the
260 * vnode or the file pointer). Note: we can't leave nl_ncp locked
261 * through the VOP_OPEN anyway since the VOP_OPEN may block, e.g.
265 cache_put(nd->nl_ncp);
269 error = VOP_OPEN(vp, fmode, cred, fp, td);
272 * setting f_ops to &badfileops will prevent the descriptor
273 * code from trying to close and release the vnode, since
274 * the open failed we do not want to call close.
278 fp->f_ops = &badfileops;
286 * Make sure that a VM object is created for VMIO support. If this
287 * fails we have to be sure to match VOP_CLOSE's with VOP_OPEN's.
288 * Cleanup the fp so we can just vput() the vp in 'bad'.
290 if (vn_canvmio(vp) == TRUE) {
291 if ((error = vfs_object_create(vp, td)) != 0) {
294 fp->f_ops = &badfileops;
296 VOP_CLOSE(vp, fmode, td);
302 * Return the vnode. XXX needs some cleaning up. The vnode is
303 * only returned in the fp == NULL case, otherwise the vnode ref
304 * is inherited by the fp and we unconditionally unlock it.
308 nd->nl_vp_fmode = fmode;
309 if ((nd->nl_flags & NLC_LOCKVP) == 0)
310 VOP_UNLOCK(vp, 0, td);
312 VOP_UNLOCK(vp, 0, td);
321 * Check for write permissions on the specified vnode.
322 * Prototype text segments cannot be written.
330 * If there's shared text associated with
331 * the vnode, try to free it up once. If
332 * we fail, we can't allow writing.
334 if (vp->v_flag & VTEXT)
343 vn_close(struct vnode *vp, int flags, struct thread *td)
349 if ((error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td)) == 0) {
350 error = VOP_CLOSE(vp, flags, td);
351 VOP_UNLOCK(vp, 0, td);
359 sequential_heuristic(struct uio *uio, struct file *fp)
362 * Sequential heuristic - detect sequential operation
364 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
365 uio->uio_offset == fp->f_nextoff) {
366 int tmpseq = fp->f_seqcount;
368 * XXX we assume that the filesystem block size is
369 * the default. Not true, but still gives us a pretty
370 * good indicator of how sequential the read operations
373 tmpseq += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE;
374 if (tmpseq > IO_SEQMAX)
376 fp->f_seqcount = tmpseq;
377 return(fp->f_seqcount << IO_SEQSHIFT);
381 * Not sequential, quick draw-down of seqcount
383 if (fp->f_seqcount > 1)
391 * Package up an I/O request on a vnode into a uio and do it.
393 * We are going to assume the caller has done the appropriate
394 * VOP_LEASE() call before calling vn_rdwr()
397 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, td)
413 if ((ioflg & IO_NODELOCKED) == 0)
414 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
415 auio.uio_iov = &aiov;
417 aiov.iov_base = base;
419 auio.uio_resid = len;
420 auio.uio_offset = offset;
421 auio.uio_segflg = segflg;
424 if (rw == UIO_READ) {
425 error = VOP_READ(vp, &auio, ioflg, cred);
427 error = VOP_WRITE(vp, &auio, ioflg, cred);
430 *aresid = auio.uio_resid;
432 if (auio.uio_resid && error == 0)
434 if ((ioflg & IO_NODELOCKED) == 0)
435 VOP_UNLOCK(vp, 0, td);
440 * Package up an I/O request on a vnode into a uio and do it. The I/O
441 * request is split up into smaller chunks and we try to avoid saturating
442 * the buffer cache while potentially holding a vnode locked, so we
443 * check bwillwrite() before calling vn_rdwr(). We also call uio_yield()
444 * to give other processes a chance to lock the vnode (either other processes
445 * core'ing the same binary, or unrelated processes scanning the directory).
448 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, td)
466 * Force `offset' to a multiple of MAXBSIZE except possibly
467 * for the first chunk, so that filesystems only need to
468 * write full blocks except possibly for the first and last
471 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
475 if (rw != UIO_READ && vp->v_type == VREG)
477 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
478 ioflg, cred, aresid, td);
479 len -= chunk; /* aresid calc already includes length */
492 * File table vnode read routine.
495 vn_read(fp, uio, cred, flags, td)
505 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
506 vp = (struct vnode *)fp->f_data;
508 if (fp->f_flag & FNONBLOCK)
510 if (fp->f_flag & O_DIRECT)
512 VOP_LEASE(vp, td, cred, LEASE_READ);
513 vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, td);
514 if ((flags & FOF_OFFSET) == 0)
515 uio->uio_offset = fp->f_offset;
517 ioflag |= sequential_heuristic(uio, fp);
519 error = VOP_READ(vp, uio, ioflag, cred);
520 if ((flags & FOF_OFFSET) == 0)
521 fp->f_offset = uio->uio_offset;
522 fp->f_nextoff = uio->uio_offset;
523 VOP_UNLOCK(vp, 0, td);
528 * Device-optimized file table vnode read routine.
530 * This bypasses the VOP table and talks directly to the device. Most
531 * filesystems just route to specfs and can make this optimization.
534 svn_read(fp, uio, cred, flags, td)
546 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
548 vp = (struct vnode *)fp->f_data;
549 if (vp == NULL || vp->v_type == VBAD)
552 if ((dev = vp->v_rdev) == NULL)
556 if (uio->uio_resid == 0)
558 if ((flags & FOF_OFFSET) == 0)
559 uio->uio_offset = fp->f_offset;
562 if (fp->f_flag & FNONBLOCK)
564 if (fp->f_flag & O_DIRECT)
566 ioflag |= sequential_heuristic(uio, fp);
568 error = dev_dread(dev, uio, ioflag);
571 if ((flags & FOF_OFFSET) == 0)
572 fp->f_offset = uio->uio_offset;
573 fp->f_nextoff = uio->uio_offset;
578 * File table vnode write routine.
581 vn_write(fp, uio, cred, flags, td)
591 KASSERT(uio->uio_td == td, ("uio_procp %p is not p %p",
593 vp = (struct vnode *)fp->f_data;
594 if (vp->v_type == VREG)
596 vp = (struct vnode *)fp->f_data; /* XXX needed? */
598 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
600 if (fp->f_flag & FNONBLOCK)
602 if (fp->f_flag & O_DIRECT)
604 if ((fp->f_flag & O_FSYNC) ||
605 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
607 VOP_LEASE(vp, td, cred, LEASE_WRITE);
608 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
609 if ((flags & FOF_OFFSET) == 0)
610 uio->uio_offset = fp->f_offset;
611 ioflag |= sequential_heuristic(uio, fp);
612 error = VOP_WRITE(vp, uio, ioflag, cred);
613 if ((flags & FOF_OFFSET) == 0)
614 fp->f_offset = uio->uio_offset;
615 fp->f_nextoff = uio->uio_offset;
616 VOP_UNLOCK(vp, 0, td);
621 * Device-optimized file table vnode write routine.
623 * This bypasses the VOP table and talks directly to the device. Most
624 * filesystems just route to specfs and can make this optimization.
627 svn_write(fp, uio, cred, flags, td)
639 KASSERT(uio->uio_td == td, ("uio_procp %p is not p %p",
642 vp = (struct vnode *)fp->f_data;
643 if (vp == NULL || vp->v_type == VBAD)
645 if (vp->v_type == VREG)
647 vp = (struct vnode *)fp->f_data; /* XXX needed? */
649 if ((dev = vp->v_rdev) == NULL)
653 if ((flags & FOF_OFFSET) == 0)
654 uio->uio_offset = fp->f_offset;
657 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
659 if (fp->f_flag & FNONBLOCK)
661 if (fp->f_flag & O_DIRECT)
663 if ((fp->f_flag & O_FSYNC) ||
664 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
666 ioflag |= sequential_heuristic(uio, fp);
668 error = dev_dwrite(dev, uio, ioflag);
671 if ((flags & FOF_OFFSET) == 0)
672 fp->f_offset = uio->uio_offset;
673 fp->f_nextoff = uio->uio_offset;
679 * File table vnode stat routine.
682 vn_statfile(struct file *fp, struct stat *sb, struct thread *td)
684 struct vnode *vp = (struct vnode *)fp->f_data;
686 return vn_stat(vp, sb, td);
690 vn_stat(struct vnode *vp, struct stat *sb, struct thread *td)
698 error = VOP_GETATTR(vp, vap, td);
703 * Zero the spare stat fields
706 sb->st_qspare[0] = 0;
707 sb->st_qspare[1] = 0;
710 * Copy from vattr table
712 if (vap->va_fsid != VNOVAL)
713 sb->st_dev = vap->va_fsid;
715 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
716 sb->st_ino = vap->va_fileid;
718 switch (vap->va_type) {
733 /* This is a cosmetic change, symlinks do not have a mode. */
734 if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW)
735 sb->st_mode &= ~ACCESSPERMS; /* 0000 */
737 sb->st_mode |= ACCESSPERMS; /* 0777 */
749 sb->st_nlink = vap->va_nlink;
750 sb->st_uid = vap->va_uid;
751 sb->st_gid = vap->va_gid;
752 sb->st_rdev = vap->va_rdev;
753 sb->st_size = vap->va_size;
754 sb->st_atimespec = vap->va_atime;
755 sb->st_mtimespec = vap->va_mtime;
756 sb->st_ctimespec = vap->va_ctime;
759 * According to www.opengroup.org, the meaning of st_blksize is
760 * "a filesystem-specific preferred I/O block size for this
761 * object. In some filesystem types, this may vary from file
763 * Default to PAGE_SIZE after much discussion.
766 if (vap->va_type == VREG) {
767 sb->st_blksize = vap->va_blocksize;
768 } else if (vn_isdisk(vp, NULL)) {
770 * XXX this is broken. If the device is not yet open (aka
771 * stat() call, aka v_rdev == NULL), how are we supposed
772 * to get a valid block size out of it?
776 if ((dev = vp->v_rdev) == NULL)
777 dev = udev2dev(vp->v_udev, vp->v_type == VBLK);
778 sb->st_blksize = dev->si_bsize_best;
779 if (sb->st_blksize < dev->si_bsize_phys)
780 sb->st_blksize = dev->si_bsize_phys;
781 if (sb->st_blksize < BLKDEV_IOSIZE)
782 sb->st_blksize = BLKDEV_IOSIZE;
784 sb->st_blksize = PAGE_SIZE;
787 sb->st_flags = vap->va_flags;
791 sb->st_gen = vap->va_gen;
793 #if (S_BLKSIZE == 512)
794 /* Optimize this case */
795 sb->st_blocks = vap->va_bytes >> 9;
797 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
803 * File table vnode ioctl routine.
806 vn_ioctl(struct file *fp, u_long com, caddr_t data, struct thread *td)
808 struct vnode *vp = ((struct vnode *)fp->f_data);
814 KKASSERT(td->td_proc != NULL);
815 ucred = td->td_proc->p_ucred;
817 switch (vp->v_type) {
820 if (com == FIONREAD) {
821 error = VOP_GETATTR(vp, &vattr, td);
824 *(int *)data = vattr.va_size - fp->f_offset;
827 if (com == FIONBIO || com == FIOASYNC) /* XXX */
828 return (0); /* XXX */
837 if (com == FIODTYPE) {
838 if (vp->v_type != VCHR && vp->v_type != VBLK)
840 *(int *)data = dev_dflags(vp->v_rdev) & D_TYPEMASK;
843 error = VOP_IOCTL(vp, com, data, fp->f_flag, ucred, td);
844 if (error == 0 && com == TIOCSCTTY) {
845 struct session *sess = td->td_proc->p_session;
847 /* Do nothing if reassigning same control tty */
848 if (sess->s_ttyvp == vp)
851 /* Get rid of reference to old control tty */
863 * File table vnode poll routine.
866 vn_poll(struct file *fp, int events, struct ucred *cred, struct thread *td)
868 return (VOP_POLL(((struct vnode *)fp->f_data), events, cred, td));
872 * Check that the vnode is still valid, and if so
873 * acquire requested lock.
877 vn_lock(struct vnode *vp, int flags, struct thread *td)
879 debug_vn_lock(struct vnode *vp, int flags, struct thread *td,
880 const char *filename, int line)
887 vp->filename = filename;
890 error = VOP_LOCK(vp, flags | LK_NOPAUSE, td);
893 } while (flags & LK_RETRY);
896 * Because we (had better!) have a ref on the vnode, once it
897 * goes to VRECLAIMED state it will not be recycled until all
898 * refs go away. So we can just check the flag.
900 if (error == 0 && (vp->v_flag & VRECLAIMED)) {
901 VOP_UNLOCK(vp, 0, td);
908 * File table vnode close routine.
911 vn_closefile(struct file *fp, struct thread *td)
915 fp->f_ops = &badfileops;
916 err = vn_close(((struct vnode *)fp->f_data), fp->f_flag, td);
921 vn_kqfilter(struct file *fp, struct knote *kn)
924 return (VOP_KQFILTER(((struct vnode *)fp->f_data), kn));