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6 * modification, are permitted provided that the following conditions
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15 * This product includes software developed by the University of
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33 * @(#)spec_vnops.c 8.14 (Berkeley) 5/21/95
34 * $FreeBSD: src/sys/miscfs/specfs/spec_vnops.c,v 1.131.2.4 2001/02/26 04:23:20 jlemon Exp $
35 * $DragonFly: src/sys/vfs/specfs/spec_vnops.c,v 1.5 2003/06/25 03:56:00 dillon Exp $
38 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
44 #include <sys/mount.h>
45 #include <sys/vnode.h>
47 #include <sys/fcntl.h>
48 #include <sys/vmmeter.h>
52 #include <vm/vm_object.h>
53 #include <vm/vm_page.h>
54 #include <vm/vm_pager.h>
58 static int spec_advlock __P((struct vop_advlock_args *));
59 static int spec_bmap __P((struct vop_bmap_args *));
60 static int spec_close __P((struct vop_close_args *));
61 static int spec_freeblks __P((struct vop_freeblks_args *));
62 static int spec_fsync __P((struct vop_fsync_args *));
63 static int spec_getpages __P((struct vop_getpages_args *));
64 static int spec_inactive __P((struct vop_inactive_args *));
65 static int spec_ioctl __P((struct vop_ioctl_args *));
66 static int spec_open __P((struct vop_open_args *));
67 static int spec_poll __P((struct vop_poll_args *));
68 static int spec_kqfilter __P((struct vop_kqfilter_args *));
69 static int spec_print __P((struct vop_print_args *));
70 static int spec_read __P((struct vop_read_args *));
71 static int spec_strategy __P((struct vop_strategy_args *));
72 static int spec_write __P((struct vop_write_args *));
74 vop_t **spec_vnodeop_p;
75 static struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
76 { &vop_default_desc, (vop_t *) vop_defaultop },
77 { &vop_access_desc, (vop_t *) vop_ebadf },
78 { &vop_advlock_desc, (vop_t *) spec_advlock },
79 { &vop_bmap_desc, (vop_t *) spec_bmap },
80 { &vop_close_desc, (vop_t *) spec_close },
81 { &vop_create_desc, (vop_t *) vop_panic },
82 { &vop_freeblks_desc, (vop_t *) spec_freeblks },
83 { &vop_fsync_desc, (vop_t *) spec_fsync },
84 { &vop_getpages_desc, (vop_t *) spec_getpages },
85 { &vop_inactive_desc, (vop_t *) spec_inactive },
86 { &vop_ioctl_desc, (vop_t *) spec_ioctl },
87 { &vop_lease_desc, (vop_t *) vop_null },
88 { &vop_link_desc, (vop_t *) vop_panic },
89 { &vop_mkdir_desc, (vop_t *) vop_panic },
90 { &vop_mknod_desc, (vop_t *) vop_panic },
91 { &vop_open_desc, (vop_t *) spec_open },
92 { &vop_pathconf_desc, (vop_t *) vop_stdpathconf },
93 { &vop_poll_desc, (vop_t *) spec_poll },
94 { &vop_kqfilter_desc, (vop_t *) spec_kqfilter },
95 { &vop_print_desc, (vop_t *) spec_print },
96 { &vop_read_desc, (vop_t *) spec_read },
97 { &vop_readdir_desc, (vop_t *) vop_panic },
98 { &vop_readlink_desc, (vop_t *) vop_panic },
99 { &vop_reallocblks_desc, (vop_t *) vop_panic },
100 { &vop_reclaim_desc, (vop_t *) vop_null },
101 { &vop_remove_desc, (vop_t *) vop_panic },
102 { &vop_rename_desc, (vop_t *) vop_panic },
103 { &vop_rmdir_desc, (vop_t *) vop_panic },
104 { &vop_setattr_desc, (vop_t *) vop_ebadf },
105 { &vop_strategy_desc, (vop_t *) spec_strategy },
106 { &vop_symlink_desc, (vop_t *) vop_panic },
107 { &vop_write_desc, (vop_t *) spec_write },
110 static struct vnodeopv_desc spec_vnodeop_opv_desc =
111 { &spec_vnodeop_p, spec_vnodeop_entries };
113 VNODEOP_SET(spec_vnodeop_opv_desc);
117 struct vop_generic_args /* {
118 struct vnodeop_desc *a_desc;
119 <other random data follows, presumably>
122 return (VOCALL(spec_vnodeop_p, ap->a_desc->vdesc_offset, ap));
125 static void spec_getpages_iodone __P((struct buf *bp));
128 * Open a special file.
133 struct vop_open_args /* {
136 struct ucred *a_cred;
140 struct vnode *vp = ap->a_vp;
141 dev_t dev = vp->v_rdev;
147 * Don't allow open if fs is mounted -nodev.
149 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV))
153 if ( (dsw == NULL) || (dsw->d_open == NULL))
156 /* Make this field valid before any I/O in ->d_open */
157 if (!dev->si_iosize_max)
158 dev->si_iosize_max = DFLTPHYS;
161 * XXX: Disks get special billing here, but it is mostly wrong.
162 * XXX: diskpartitions can overlap and the real checks should
163 * XXX: take this into account, and consequently they need to
164 * XXX: live in the diskslicing code. Some checks do.
166 if (vn_isdisk(vp, NULL) && ap->a_cred != FSCRED &&
167 (ap->a_mode & FWRITE)) {
169 * Never allow opens for write if the device is mounted R/W
171 if (vp->v_specmountpoint != NULL &&
172 !(vp->v_specmountpoint->mnt_flag & MNT_RDONLY))
176 * When running in secure mode, do not allow opens
177 * for writing if the device is mounted
179 if (securelevel >= 1 && vp->v_specmountpoint != NULL)
183 * When running in very secure mode, do not allow
184 * opens for writing of any devices.
186 if (securelevel >= 2)
190 /* XXX: Special casing of ttys for deadfs. Probably redundant */
191 if (dsw->d_flags & D_TTY)
192 vp->v_flag |= VISTTY;
194 VOP_UNLOCK(vp, 0, ap->a_td);
195 error = (*dsw->d_open)(dev, ap->a_mode, S_IFCHR, ap->a_td);
196 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_td);
201 if (dsw->d_flags & D_TTY) {
206 printf("Warning:%s: no t_stop, using nottystop\n", devtoname(dev));
207 tp->t_stop = nottystop;
212 if (vn_isdisk(vp, NULL)) {
213 if (!dev->si_bsize_phys)
214 dev->si_bsize_phys = DEV_BSIZE;
216 if ((dsw->d_flags & D_DISK) == 0) {
218 if (*cp == '#' && (dsw->d_flags & D_NAGGED) == 0) {
219 printf("WARNING: driver %s should register devices with make_dev() (dev_t = \"%s\")\n",
221 dsw->d_flags |= D_NAGGED;
233 struct vop_read_args /* {
237 struct ucred *a_cred;
251 if (uio->uio_resid == 0)
254 VOP_UNLOCK(vp, 0, td);
255 error = (*devsw(dev)->d_read) (dev, uio, ap->a_ioflag);
256 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
266 struct vop_write_args /* {
270 struct ucred *a_cred;
284 VOP_UNLOCK(vp, 0, td);
285 error = (*devsw(dev)->d_write) (dev, uio, ap->a_ioflag);
286 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
291 * Device ioctl operation.
296 struct vop_ioctl_args /* {
301 struct ucred *a_cred;
307 dev = ap->a_vp->v_rdev;
308 return ((*devsw(dev)->d_ioctl)(dev, ap->a_command,
309 ap->a_data, ap->a_fflag, ap->a_td));
315 struct vop_poll_args /* {
318 struct ucred *a_cred;
324 dev = ap->a_vp->v_rdev;
325 return (*devsw(dev)->d_poll)(dev, ap->a_events, ap->a_td);
331 struct vop_kqfilter_args /* {
338 dev = ap->a_vp->v_rdev;
339 if (devsw(dev)->d_flags & D_KQFILTER)
340 return (*devsw(dev)->d_kqfilter)(dev, ap->a_kn);
345 * Synch buffers associated with a block device
350 struct vop_fsync_args /* {
352 struct ucred *a_cred;
357 struct vnode *vp = ap->a_vp;
361 int maxretry = 10000; /* large, arbitrarily chosen */
363 if (!vn_isdisk(vp, NULL))
368 * MARK/SCAN initialization to avoid infinite loops
371 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp;
372 bp = TAILQ_NEXT(bp, b_vnbufs)) {
373 bp->b_flags &= ~B_SCANNED;
378 * Flush all dirty buffers associated with a block device.
382 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
383 nbp = TAILQ_NEXT(bp, b_vnbufs);
384 if ((bp->b_flags & B_SCANNED) != 0)
386 bp->b_flags |= B_SCANNED;
387 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
389 if ((bp->b_flags & B_DELWRI) == 0)
390 panic("spec_fsync: not dirty");
391 if ((vp->v_flag & VOBJBUF) && (bp->b_flags & B_CLUSTEROK)) {
404 * If synchronous the caller expects us to completely resolve all
405 * dirty buffers in the system. Wait for in-progress I/O to
406 * complete (which could include background bitmap writes), then
407 * retry if dirty blocks still exist.
409 if (ap->a_waitfor == MNT_WAIT) {
410 while (vp->v_numoutput) {
411 vp->v_flag |= VBWAIT;
412 (void) tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "spfsyn", 0);
414 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
415 if (--maxretry != 0) {
419 vprint("spec_fsync: giving up on dirty", vp);
428 struct vop_inactive_args /* {
434 VOP_UNLOCK(ap->a_vp, 0, ap->a_td);
439 * Just call the device strategy routine
443 struct vop_strategy_args /* {
453 if (((bp->b_flags & B_READ) == 0) &&
454 (LIST_FIRST(&bp->b_dep)) != NULL && bioops.io_start)
455 (*bioops.io_start)(bp);
458 * Collect statistics on synchronous and asynchronous read
459 * and write counts for disks that have associated filesystems.
462 if (vn_isdisk(vp, NULL) && (mp = vp->v_specmountpoint) != NULL) {
463 if ((bp->b_flags & B_READ) == 0) {
464 if (bp->b_lock.lk_lockholder == LK_KERNTHREAD)
465 mp->mnt_stat.f_asyncwrites++;
467 mp->mnt_stat.f_syncwrites++;
469 if (bp->b_lock.lk_lockholder == LK_KERNTHREAD)
470 mp->mnt_stat.f_asyncreads++;
472 mp->mnt_stat.f_syncreads++;
475 KASSERT(devsw(bp->b_dev) != NULL,
476 ("No devsw on dev %s responsible for buffer %p\n",
477 devtoname(bp->b_dev), bp));
478 KASSERT(devsw(bp->b_dev)->d_strategy != NULL,
479 ("No strategy on dev %s responsible for buffer %p\n",
480 devtoname(bp->b_dev), bp));
487 struct vop_freeblks_args /* {
497 * XXX: This assumes that strategy does the deed right away.
498 * XXX: this may not be TRTTD.
500 bsw = devsw(ap->a_vp->v_rdev);
501 if ((bsw->d_flags & D_CANFREE) == 0)
503 bp = geteblk(ap->a_length);
504 bp->b_flags |= B_FREEBUF;
505 bp->b_dev = ap->a_vp->v_rdev;
506 bp->b_blkno = ap->a_addr;
507 bp->b_offset = dbtob(ap->a_addr);
508 bp->b_bcount = ap->a_length;
514 * Implement degenerate case where the block requested is the block
515 * returned, and assume that the entire device is contiguous in regards
516 * to the contiguous block range (runp and runb).
520 struct vop_bmap_args /* {
523 struct vnode **a_vpp;
529 struct vnode *vp = ap->a_vp;
533 if (ap->a_vpp != NULL)
535 if (ap->a_bnp != NULL)
536 *ap->a_bnp = ap->a_bn;
537 if (vp->v_mount != NULL)
538 runp = runb = MAXBSIZE / vp->v_mount->mnt_stat.f_iosize;
539 if (ap->a_runp != NULL)
541 if (ap->a_runb != NULL)
547 * Device close routine
552 struct vop_close_args /* {
555 struct ucred *a_cred;
559 struct proc *p = ap->a_td->td_proc;
560 struct vnode *vp = ap->a_vp;
561 dev_t dev = vp->v_rdev;
564 * Hack: a tty device that is a controlling terminal
565 * has a reference from the session structure.
566 * We cannot easily tell that a character device is
567 * a controlling terminal, unless it is the closing
568 * process' controlling terminal. In that case,
569 * if the reference count is 2 (this last descriptor
570 * plus the session), release the reference from the session.
572 if (vcount(vp) == 2 && p && (vp->v_flag & VXLOCK) == 0 &&
573 vp == p->p_session->s_ttyvp) {
575 p->p_session->s_ttyvp = NULL;
578 * We do not want to really close the device if it
579 * is still in use unless we are trying to close it
580 * forcibly. Since every use (buffer, vnode, swap, cmap)
581 * holds a reference to the vnode, and because we mark
582 * any other vnodes that alias this device, when the
583 * sum of the reference counts on all the aliased
584 * vnodes descends to one, we are on last close.
586 if (vp->v_flag & VXLOCK) {
588 } else if (devsw(dev)->d_flags & D_TRACKCLOSE) {
589 /* Keep device updated on status */
590 } else if (vcount(vp) > 1) {
593 return (devsw(dev)->d_close(dev, ap->a_fflag, S_IFCHR, ap->a_td));
597 * Print out the contents of a special device vnode.
601 struct vop_print_args /* {
606 printf("tag VT_NON, dev %s\n", devtoname(ap->a_vp->v_rdev));
611 * Special device advisory byte-level locks.
616 struct vop_advlock_args /* {
625 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL);
629 spec_getpages_iodone(bp)
633 bp->b_flags |= B_DONE;
639 struct vop_getpages_args *ap;
643 int i, pcount, size, s;
648 int toff, nextoff, nread;
649 struct vnode *vp = ap->a_vp;
654 pcount = round_page(ap->a_count) / PAGE_SIZE;
657 * Calculate the offset of the transfer and do sanity check.
658 * FreeBSD currently only supports an 8 TB range due to b_blkno
659 * being in DEV_BSIZE ( usually 512 ) byte chunks on call to
662 offset = IDX_TO_OFF(ap->a_m[0]->pindex) + ap->a_offset;
664 #define DADDR_T_BIT (sizeof(daddr_t)*8)
665 #define OFFSET_MAX ((1LL << (DADDR_T_BIT + DEV_BSHIFT)) - 1)
667 if (offset < 0 || offset > OFFSET_MAX) {
668 /* XXX still no %q in kernel. */
669 printf("spec_getpages: preposterous offset 0x%x%08x\n",
670 (u_int)((u_quad_t)offset >> 32),
671 (u_int)(offset & 0xffffffff));
672 return (VM_PAGER_ERROR);
675 blkno = btodb(offset);
678 * Round up physical size for real devices. We cannot round using
679 * v_mount's block size data because v_mount has nothing to do with
680 * the device. i.e. it's usually '/dev'. We need the physical block
681 * size for the device itself.
683 * We can't use v_specmountpoint because it only exists when the
684 * block device is mounted. However, we can use v_rdev.
687 if (vn_isdisk(vp, NULL))
688 blksiz = vp->v_rdev->si_bsize_phys;
692 size = (ap->a_count + blksiz - 1) & ~(blksiz - 1);
695 kva = (vm_offset_t)bp->b_data;
698 * Map the pages to be read into the kva.
700 pmap_qenter(kva, ap->a_m, pcount);
702 /* Build a minimal buffer header. */
703 bp->b_flags = B_READ | B_CALL;
704 bp->b_iodone = spec_getpages_iodone;
706 /* B_PHYS is not set, but it is nice to fill this in. */
707 bp->b_rcred = bp->b_wcred = curproc->p_ucred;
708 if (bp->b_rcred != NOCRED)
710 if (bp->b_wcred != NOCRED)
713 bp->b_lblkno = blkno;
714 pbgetvp(ap->a_vp, bp);
716 bp->b_bufsize = size;
718 bp->b_runningbufspace = bp->b_bufsize;
719 runningbufspace += bp->b_runningbufspace;
722 cnt.v_vnodepgsin += pcount;
725 VOP_STRATEGY(bp->b_vp, bp);
729 /* We definitely need to be at splbio here. */
730 while ((bp->b_flags & B_DONE) == 0)
731 tsleep(bp, PVM, "spread", 0);
735 if ((bp->b_flags & B_ERROR) != 0) {
742 nread = size - bp->b_resid;
744 if (nread < ap->a_count) {
745 bzero((caddr_t)kva + nread,
746 ap->a_count - nread);
748 pmap_qremove(kva, pcount);
752 for (i = 0, toff = 0; i < pcount; i++, toff = nextoff) {
753 nextoff = toff + PAGE_SIZE;
756 m->flags &= ~PG_ZERO;
758 if (nextoff <= nread) {
759 m->valid = VM_PAGE_BITS_ALL;
761 } else if (toff < nread) {
763 * Since this is a VM request, we have to supply the
764 * unaligned offset to allow vm_page_set_validclean()
765 * to zero sub-DEV_BSIZE'd portions of the page.
767 vm_page_set_validclean(m, 0, nread - toff);
773 if (i != ap->a_reqpage) {
775 * Just in case someone was asking for this page we
776 * now tell them that it is ok to use.
778 if (!error || (m->valid == VM_PAGE_BITS_ALL)) {
780 if (m->flags & PG_WANTED) {
783 vm_page_deactivate(m);
792 } else if (m->valid) {
795 * Since this is a VM request, we need to make the
796 * entire page presentable by zeroing invalid sections.
798 if (m->valid != VM_PAGE_BITS_ALL)
799 vm_page_zero_invalid(m, FALSE);
803 m = ap->a_m[ap->a_reqpage];
805 "spec_getpages:(%s) I/O read failure: (error=%d) bp %p vp %p\n",
806 devtoname(bp->b_dev), error, bp, bp->b_vp);
808 " size: %d, resid: %ld, a_count: %d, valid: 0x%x\n",
809 size, bp->b_resid, ap->a_count, m->valid);
811 " nread: %d, reqpage: %d, pindex: %lu, pcount: %d\n",
812 nread, ap->a_reqpage, (u_long)m->pindex, pcount);
814 * Free the buffer header back to the swap buffer pool.
817 return VM_PAGER_ERROR;
820 * Free the buffer header back to the swap buffer pool.