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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 1.15 2003/10/09 22:27:19 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/namei.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 vn_poll (struct file *fp, int events, struct ucred *cred,
65 static int vn_kqfilter (struct file *fp, struct knote *kn);
66 static int vn_statfile (struct file *fp, struct stat *sb, struct thread *td);
67 static int vn_write (struct file *fp, struct uio *uio,
68 struct ucred *cred, int flags, struct thread *td);
70 struct fileops vnops = {
73 vn_read, vn_write, vn_ioctl, vn_poll, vn_kqfilter,
74 vn_statfile, vn_closefile
78 * Common code for vnode open operations.
79 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
81 * Note that this does NOT free nameidata for the successful case,
82 * due to the NDINIT being done elsewhere.
85 vn_open(ndp, fmode, cmode)
86 struct nameidata *ndp;
90 struct thread *td = ndp->ni_cnd.cn_td;
91 struct ucred *cred = ndp->ni_cnd.cn_cred;
93 struct vattr *vap = &vat;
96 KKASSERT(cred == td->td_proc->p_ucred);
98 if (fmode & O_CREAT) {
99 ndp->ni_cnd.cn_nameiop = NAMEI_CREATE;
100 ndp->ni_cnd.cn_flags = CNP_LOCKPARENT | CNP_LOCKLEAF;
101 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
102 ndp->ni_cnd.cn_flags |= CNP_FOLLOW;
107 if (ndp->ni_vp == NULL) {
110 vap->va_mode = cmode;
112 vap->va_vaflags |= VA_EXCLUSIVE;
113 VOP_LEASE(ndp->ni_dvp, td, cred, LEASE_WRITE);
114 error = VOP_CREATE(ndp->ni_dvp, NCPNULL, &ndp->ni_vp,
117 NDFREE(ndp, NDF_ONLY_PNBUF);
122 ASSERT_VOP_UNLOCKED(ndp->ni_dvp, "create");
123 ASSERT_VOP_LOCKED(ndp->ni_vp, "create");
127 if (ndp->ni_dvp == ndp->ni_vp)
133 if (fmode & O_EXCL) {
140 ndp->ni_cnd.cn_nameiop = NAMEI_LOOKUP;
141 ndp->ni_cnd.cn_flags = CNP_LOCKLEAF |
142 ((fmode & O_NOFOLLOW) ? 0 : CNP_FOLLOW);
148 if (vp->v_type == VLNK) {
152 if (vp->v_type == VSOCK) {
156 if ((fmode & O_CREAT) == 0) {
158 if (fmode & (FWRITE | O_TRUNC)) {
159 if (vp->v_type == VDIR) {
163 error = vn_writechk(vp);
171 error = VOP_ACCESS(vp, mode, cred, td);
176 if (fmode & O_TRUNC) {
177 VOP_UNLOCK(vp, 0, td); /* XXX */
178 VOP_LEASE(vp, td, cred, LEASE_WRITE);
179 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); /* XXX */
182 error = VOP_SETATTR(vp, vap, cred, td);
186 error = VOP_OPEN(vp, fmode, cred, td);
190 * Make sure that a VM object is created for VMIO support.
192 if (vn_canvmio(vp) == TRUE) {
193 if ((error = vfs_object_create(vp, td)) != 0)
201 NDFREE(ndp, NDF_ONLY_PNBUF);
207 * Check for write permissions on the specified vnode.
208 * Prototype text segments cannot be written.
216 * If there's shared text associated with
217 * the vnode, try to free it up once. If
218 * we fail, we can't allow writing.
220 if (vp->v_flag & VTEXT)
229 vn_close(struct vnode *vp, int flags, struct thread *td)
235 error = VOP_CLOSE(vp, flags, td);
242 sequential_heuristic(struct uio *uio, struct file *fp)
245 * Sequential heuristic - detect sequential operation
247 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
248 uio->uio_offset == fp->f_nextoff) {
249 int tmpseq = fp->f_seqcount;
251 * XXX we assume that the filesystem block size is
252 * the default. Not true, but still gives us a pretty
253 * good indicator of how sequential the read operations
256 tmpseq += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE;
257 if (tmpseq > IO_SEQMAX)
259 fp->f_seqcount = tmpseq;
260 return(fp->f_seqcount << IO_SEQSHIFT);
264 * Not sequential, quick draw-down of seqcount
266 if (fp->f_seqcount > 1)
274 * Package up an I/O request on a vnode into a uio and do it.
277 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, td)
293 if ((ioflg & IO_NODELOCKED) == 0)
294 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
295 auio.uio_iov = &aiov;
297 aiov.iov_base = base;
299 auio.uio_resid = len;
300 auio.uio_offset = offset;
301 auio.uio_segflg = segflg;
304 if (rw == UIO_READ) {
305 error = VOP_READ(vp, &auio, ioflg, cred);
307 error = VOP_WRITE(vp, &auio, ioflg, cred);
310 *aresid = auio.uio_resid;
312 if (auio.uio_resid && error == 0)
314 if ((ioflg & IO_NODELOCKED) == 0)
315 VOP_UNLOCK(vp, 0, td);
320 * Package up an I/O request on a vnode into a uio and do it. The I/O
321 * request is split up into smaller chunks and we try to avoid saturating
322 * the buffer cache while potentially holding a vnode locked, so we
323 * check bwillwrite() before calling vn_rdwr(). We also call uio_yield()
324 * to give other processes a chance to lock the vnode (either other processes
325 * core'ing the same binary, or unrelated processes scanning the directory).
328 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, td)
343 int chunk = (len > MAXBSIZE) ? MAXBSIZE : len;
345 if (rw != UIO_READ && vp->v_type == VREG)
347 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
348 ioflg, cred, aresid, td);
349 len -= chunk; /* aresid calc already includes length */
362 * File table vnode read routine.
365 vn_read(fp, uio, cred, flags, td)
375 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
376 vp = (struct vnode *)fp->f_data;
378 if (fp->f_flag & FNONBLOCK)
380 if (fp->f_flag & O_DIRECT)
382 VOP_LEASE(vp, td, cred, LEASE_READ);
383 vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, td);
384 if ((flags & FOF_OFFSET) == 0)
385 uio->uio_offset = fp->f_offset;
387 ioflag |= sequential_heuristic(uio, fp);
389 error = VOP_READ(vp, uio, ioflag, cred);
390 if ((flags & FOF_OFFSET) == 0)
391 fp->f_offset = uio->uio_offset;
392 fp->f_nextoff = uio->uio_offset;
393 VOP_UNLOCK(vp, 0, td);
398 * File table vnode write routine.
401 vn_write(fp, uio, cred, flags, td)
411 KASSERT(uio->uio_td == td, ("uio_procp %p is not p %p",
413 vp = (struct vnode *)fp->f_data;
414 if (vp->v_type == VREG)
416 vp = (struct vnode *)fp->f_data; /* XXX needed? */
418 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
420 if (fp->f_flag & FNONBLOCK)
422 if (fp->f_flag & O_DIRECT)
424 if ((fp->f_flag & O_FSYNC) ||
425 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
427 VOP_LEASE(vp, td, cred, LEASE_WRITE);
428 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
429 if ((flags & FOF_OFFSET) == 0)
430 uio->uio_offset = fp->f_offset;
431 ioflag |= sequential_heuristic(uio, fp);
432 error = VOP_WRITE(vp, uio, ioflag, cred);
433 if ((flags & FOF_OFFSET) == 0)
434 fp->f_offset = uio->uio_offset;
435 fp->f_nextoff = uio->uio_offset;
436 VOP_UNLOCK(vp, 0, td);
441 * File table vnode stat routine.
444 vn_statfile(struct file *fp, struct stat *sb, struct thread *td)
446 struct vnode *vp = (struct vnode *)fp->f_data;
448 return vn_stat(vp, sb, td);
452 vn_stat(struct vnode *vp, struct stat *sb, struct thread *td)
460 error = VOP_GETATTR(vp, vap, td);
465 * Zero the spare stat fields
468 sb->st_qspare[0] = 0;
469 sb->st_qspare[1] = 0;
472 * Copy from vattr table
474 if (vap->va_fsid != VNOVAL)
475 sb->st_dev = vap->va_fsid;
477 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
478 sb->st_ino = vap->va_fileid;
480 switch (vap->va_type) {
495 /* This is a cosmetic change, symlinks do not have a mode. */
496 if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW)
497 sb->st_mode &= ~ACCESSPERMS; /* 0000 */
499 sb->st_mode |= ACCESSPERMS; /* 0777 */
511 sb->st_nlink = vap->va_nlink;
512 sb->st_uid = vap->va_uid;
513 sb->st_gid = vap->va_gid;
514 sb->st_rdev = vap->va_rdev;
515 sb->st_size = vap->va_size;
516 sb->st_atimespec = vap->va_atime;
517 sb->st_mtimespec = vap->va_mtime;
518 sb->st_ctimespec = vap->va_ctime;
521 * According to www.opengroup.org, the meaning of st_blksize is
522 * "a filesystem-specific preferred I/O block size for this
523 * object. In some filesystem types, this may vary from file
525 * Default to PAGE_SIZE after much discussion.
528 if (vap->va_type == VREG) {
529 sb->st_blksize = vap->va_blocksize;
530 } else if (vn_isdisk(vp, NULL)) {
531 sb->st_blksize = vp->v_rdev->si_bsize_best;
532 if (sb->st_blksize < vp->v_rdev->si_bsize_phys)
533 sb->st_blksize = vp->v_rdev->si_bsize_phys;
534 if (sb->st_blksize < BLKDEV_IOSIZE)
535 sb->st_blksize = BLKDEV_IOSIZE;
537 sb->st_blksize = PAGE_SIZE;
540 sb->st_flags = vap->va_flags;
544 sb->st_gen = vap->va_gen;
546 #if (S_BLKSIZE == 512)
547 /* Optimize this case */
548 sb->st_blocks = vap->va_bytes >> 9;
550 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
556 * File table vnode ioctl routine.
559 vn_ioctl(struct file *fp, u_long com, caddr_t data, struct thread *td)
561 struct vnode *vp = ((struct vnode *)fp->f_data);
566 KKASSERT(td->td_proc != NULL);
567 ucred = td->td_proc->p_ucred;
569 switch (vp->v_type) {
572 if (com == FIONREAD) {
573 error = VOP_GETATTR(vp, &vattr, td);
576 *(int *)data = vattr.va_size - fp->f_offset;
579 if (com == FIONBIO || com == FIOASYNC) /* XXX */
580 return (0); /* XXX */
589 if (com == FIODTYPE) {
590 if (vp->v_type != VCHR && vp->v_type != VBLK)
592 *(int *)data = dev_dflags(vp->v_rdev) & D_TYPEMASK;
595 error = VOP_IOCTL(vp, com, data, fp->f_flag, ucred, td);
596 if (error == 0 && com == TIOCSCTTY) {
597 struct session *sess = td->td_proc->p_session;
599 /* Do nothing if reassigning same control tty */
600 if (sess->s_ttyvp == vp)
603 /* Get rid of reference to old control tty */
605 vrele(sess->s_ttyvp);
615 * File table vnode poll routine.
618 vn_poll(struct file *fp, int events, struct ucred *cred, struct thread *td)
620 return (VOP_POLL(((struct vnode *)fp->f_data), events, cred, td));
624 * Check that the vnode is still valid, and if so
625 * acquire requested lock.
629 vn_lock(struct vnode *vp, int flags, struct thread *td)
631 debug_vn_lock(struct vnode *vp, int flags, struct thread *td,
632 const char *filename, int line)
638 if ((flags & LK_INTERLOCK) == 0)
639 lwkt_gettoken(&vp->v_interlock);
640 if ((vp->v_flag & VXLOCK) && vp->v_vxproc != curproc) {
641 vp->v_flag |= VXWANT;
642 lwkt_reltoken(&vp->v_interlock);
643 tsleep((caddr_t)vp, 0, "vn_lock", 0);
647 /* this can now occur in normal operation */
648 if (vp->v_vxproc != NULL)
649 log(LOG_INFO, "VXLOCK interlock avoided in vn_lock\n");
652 vp->filename = filename;
656 flags | LK_NOPAUSE | LK_INTERLOCK, td);
660 flags &= ~LK_INTERLOCK;
661 } while (flags & LK_RETRY);
666 * File table vnode close routine.
669 vn_closefile(struct file *fp, struct thread *td)
673 fp->f_ops = &badfileops;
674 err = vn_close(((struct vnode *)fp->f_data), fp->f_flag, td);
679 vn_kqfilter(struct file *fp, struct knote *kn)
682 return (VOP_KQFILTER(((struct vnode *)fp->f_data), kn));