2 * Copyright (c) 1989, 1993, 1995
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
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12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
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18 * may be used to endorse or promote products derived from this software
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23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 1.22 2004/11/12 00:09:50 dillon Exp $
38 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
44 #include <sys/device.h>
45 #include <sys/mount.h>
46 #include <sys/vnode.h>
48 #include <sys/fcntl.h>
49 #include <sys/vmmeter.h>
53 #include <vm/vm_object.h>
54 #include <vm/vm_page.h>
55 #include <vm/vm_pager.h>
59 static int spec_advlock (struct vop_advlock_args *);
60 static int spec_bmap (struct vop_bmap_args *);
61 static int spec_close (struct vop_close_args *);
62 static int spec_freeblks (struct vop_freeblks_args *);
63 static int spec_fsync (struct vop_fsync_args *);
64 static int spec_getpages (struct vop_getpages_args *);
65 static int spec_inactive (struct vop_inactive_args *);
66 static int spec_ioctl (struct vop_ioctl_args *);
67 static int spec_open (struct vop_open_args *);
68 static int spec_poll (struct vop_poll_args *);
69 static int spec_kqfilter (struct vop_kqfilter_args *);
70 static int spec_print (struct vop_print_args *);
71 static int spec_read (struct vop_read_args *);
72 static int spec_strategy (struct vop_strategy_args *);
73 static int spec_write (struct vop_write_args *);
75 struct vop_ops *spec_vnode_vops;
76 struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
77 { &vop_default_desc, vop_defaultop },
78 { &vop_access_desc, vop_ebadf },
79 { &vop_advlock_desc, (void *) spec_advlock },
80 { &vop_bmap_desc, (void *) spec_bmap },
81 { &vop_close_desc, (void *) spec_close },
82 { &vop_create_desc, vop_panic },
83 { &vop_freeblks_desc, (void *) spec_freeblks },
84 { &vop_fsync_desc, (void *) spec_fsync },
85 { &vop_getpages_desc, (void *) spec_getpages },
86 { &vop_inactive_desc, (void *) spec_inactive },
87 { &vop_ioctl_desc, (void *) spec_ioctl },
88 { &vop_lease_desc, vop_null },
89 { &vop_link_desc, vop_panic },
90 { &vop_mkdir_desc, vop_panic },
91 { &vop_mknod_desc, vop_panic },
92 { &vop_open_desc, (void *) spec_open },
93 { &vop_pathconf_desc, (void *) vop_stdpathconf },
94 { &vop_poll_desc, (void *) spec_poll },
95 { &vop_kqfilter_desc, (void *) spec_kqfilter },
96 { &vop_print_desc, (void *) spec_print },
97 { &vop_read_desc, (void *) spec_read },
98 { &vop_readdir_desc, vop_panic },
99 { &vop_readlink_desc, vop_panic },
100 { &vop_reallocblks_desc, vop_panic },
101 { &vop_reclaim_desc, vop_null },
102 { &vop_remove_desc, vop_panic },
103 { &vop_rename_desc, vop_panic },
104 { &vop_rmdir_desc, vop_panic },
105 { &vop_setattr_desc, vop_ebadf },
106 { &vop_strategy_desc, (void *) spec_strategy },
107 { &vop_symlink_desc, vop_panic },
108 { &vop_write_desc, (void *) spec_write },
111 static struct vnodeopv_desc spec_vnodeop_opv_desc =
112 { &spec_vnode_vops, spec_vnodeop_entries };
113 VNODEOP_SET(spec_vnodeop_opv_desc);
115 extern int dev_ref_debug;
118 * spec_vnoperate(struct vnodeop_desc *a_desc, ...)
121 spec_vnoperate(struct vop_generic_args *ap)
123 return (VOCALL(spec_vnode_vops, ap));
126 static void spec_getpages_iodone (struct buf *bp);
129 * Open a special file.
131 * spec_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred,
132 * struct thread *a_td)
136 spec_open(struct vop_open_args *ap)
138 struct vnode *vp = ap->a_vp;
141 int isblk = (vp->v_type == VBLK) ? 1 : 0;
145 * Don't allow open if fs is mounted -nodev.
147 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV))
151 * Resolve the device. If the vnode is already open v_rdev may
152 * already be resolved. However, if the device changes out from
153 * under us we report it (and, for now, we allow it). Since
154 * v_release_rdev() zero's v_opencount, we have to save and restore
155 * it when replacing the rdev reference.
157 if (vp->v_rdev != NULL) {
158 dev = udev2dev(vp->v_udev, isblk);
159 if (dev != vp->v_rdev) {
160 int oc = vp->v_opencount;
162 "Warning: spec_open: dev %s was lost",
163 vp->v_rdev->si_name);
165 error = v_associate_rdev(vp,
166 udev2dev(vp->v_udev, isblk));
168 printf(", reacquisition failed\n");
170 vp->v_opencount = oc;
171 printf(", reacquisition successful\n");
177 error = v_associate_rdev(vp, udev2dev(vp->v_udev, isblk));
183 * Prevent degenerate open/close sequences from nulling out rdev.
187 KKASSERT(dev != NULL);
190 * Make this field valid before any I/O in ->d_open. XXX the
191 * device itself should probably be required to initialize
192 * this field in d_open.
194 if (!dev->si_iosize_max)
195 dev->si_iosize_max = DFLTPHYS;
198 * XXX: Disks get special billing here, but it is mostly wrong.
199 * XXX: diskpartitions can overlap and the real checks should
200 * XXX: take this into account, and consequently they need to
201 * XXX: live in the diskslicing code. Some checks do.
203 if (vn_isdisk(vp, NULL) && ap->a_cred != FSCRED &&
204 (ap->a_mode & FWRITE)) {
206 * Never allow opens for write if the device is mounted R/W
208 if (vp->v_rdev && vp->v_rdev->si_mountpoint &&
209 !(vp->v_rdev->si_mountpoint->mnt_flag & MNT_RDONLY)) {
215 * When running in secure mode, do not allow opens
216 * for writing if the device is mounted
218 if (securelevel >= 1 && vfs_mountedon(vp)) {
224 * When running in very secure mode, do not allow
225 * opens for writing of any devices.
227 if (securelevel >= 2) {
233 /* XXX: Special casing of ttys for deadfs. Probably redundant */
234 if (dev_dflags(dev) & D_TTY)
235 vp->v_flag |= VISTTY;
238 * dev_dopen() is always called for each open. dev_dclose() is
239 * only called for the last close unless D_TRACKCLOSE is set.
241 VOP_UNLOCK(vp, 0, ap->a_td);
242 error = dev_dopen(dev, ap->a_mode, S_IFCHR, ap->a_td);
243 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_td);
248 if (dev_dflags(dev) & D_TTY) {
253 printf("Warning:%s: no t_stop, using nottystop\n", devtoname(dev));
254 tp->t_stop = nottystop;
259 if (vn_isdisk(vp, NULL)) {
260 if (!dev->si_bsize_phys)
261 dev->si_bsize_phys = DEV_BSIZE;
263 if ((dev_dflags(dev) & D_DISK) == 0) {
266 printf("WARNING: driver %s should register devices with make_dev() (dev_t = \"%s\")\n",
272 * If we were handed a file pointer we may be able to install a
273 * shortcut which issues device read and write operations directly
274 * from the fileops rather then having to go through spec_read()
278 vn_setspecops(ap->a_fp);
281 printf("spec_open: %s %d\n", dev->si_name, vp->v_opencount);
284 KKASSERT(vp->v_opencount > 0);
285 if (--vp->v_opencount == 0)
294 * spec_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
295 * struct ucred *a_cred)
299 spec_read(struct vop_read_args *ap)
312 if (dev == NULL) /* device was revoked */
314 if (uio->uio_resid == 0)
317 VOP_UNLOCK(vp, 0, td);
318 error = dev_dread(dev, uio, ap->a_ioflag);
319 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
326 * spec_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
327 * struct ucred *a_cred)
331 spec_write(struct vop_write_args *ap)
344 if (dev == NULL) /* device was revoked */
347 VOP_UNLOCK(vp, 0, td);
348 error = dev_dwrite(dev, uio, ap->a_ioflag);
349 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
354 * Device ioctl operation.
356 * spec_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data,
357 * int a_fflag, struct ucred *a_cred, struct thread *a_td)
361 spec_ioctl(struct vop_ioctl_args *ap)
365 if ((dev = ap->a_vp->v_rdev) == NULL)
366 return (EBADF); /* device was revoked */
368 return (dev_dioctl(dev, ap->a_command, ap->a_data,
369 ap->a_fflag, ap->a_td));
373 * spec_poll(struct vnode *a_vp, int a_events, struct ucred *a_cred,
374 * struct thread *a_td)
378 spec_poll(struct vop_poll_args *ap)
382 if ((dev = ap->a_vp->v_rdev) == NULL)
383 return (EBADF); /* device was revoked */
384 return (dev_dpoll(dev, ap->a_events, ap->a_td));
388 * spec_kqfilter(struct vnode *a_vp, struct knote *a_kn)
392 spec_kqfilter(struct vop_kqfilter_args *ap)
396 if ((dev = ap->a_vp->v_rdev) == NULL)
397 return (EBADF); /* device was revoked */
398 return (dev_dkqfilter(dev, ap->a_kn));
402 * Synch buffers associated with a block device
404 * spec_fsync(struct vnode *a_vp, struct ucred *a_cred,
405 * int a_waitfor, struct thread *a_td)
409 spec_fsync(struct vop_fsync_args *ap)
411 struct vnode *vp = ap->a_vp;
415 int maxretry = 10000; /* large, arbitrarily chosen */
417 if (!vn_isdisk(vp, NULL))
422 * MARK/SCAN initialization to avoid infinite loops
425 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp;
426 bp = TAILQ_NEXT(bp, b_vnbufs)) {
427 bp->b_flags &= ~B_SCANNED;
432 * Flush all dirty buffers associated with a block device.
436 for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
437 nbp = TAILQ_NEXT(bp, b_vnbufs);
438 if ((bp->b_flags & B_SCANNED) != 0)
440 bp->b_flags |= B_SCANNED;
441 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
443 if ((bp->b_flags & B_DELWRI) == 0)
444 panic("spec_fsync: not dirty");
445 if ((vp->v_flag & VOBJBUF) && (bp->b_flags & B_CLUSTEROK)) {
458 * If synchronous the caller expects us to completely resolve all
459 * dirty buffers in the system. Wait for in-progress I/O to
460 * complete (which could include background bitmap writes), then
461 * retry if dirty blocks still exist.
463 if (ap->a_waitfor == MNT_WAIT) {
464 while (vp->v_numoutput) {
465 vp->v_flag |= VBWAIT;
466 (void) tsleep((caddr_t)&vp->v_numoutput, 0, "spfsyn", 0);
468 if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
469 if (--maxretry != 0) {
473 vprint("spec_fsync: giving up on dirty", vp);
481 * spec_inactive(struct vnode *a_vp, struct thread *a_td)
484 spec_inactive(struct vop_inactive_args *ap)
490 * Just call the device strategy routine
492 * spec_strategy(struct vnode *a_vp, struct buf *a_bp)
495 spec_strategy(struct vop_strategy_args *ap)
502 if (((bp->b_flags & B_READ) == 0) &&
503 (LIST_FIRST(&bp->b_dep)) != NULL && bioops.io_start)
504 (*bioops.io_start)(bp);
507 * Collect statistics on synchronous and asynchronous read
508 * and write counts for disks that have associated filesystems.
511 KKASSERT(vp->v_rdev != NULL); /* XXX */
512 if (vn_isdisk(vp, NULL) && (mp = vp->v_rdev->si_mountpoint) != NULL) {
513 if ((bp->b_flags & B_READ) == 0) {
514 if (bp->b_lock.lk_lockholder == LK_KERNTHREAD)
515 mp->mnt_stat.f_asyncwrites++;
517 mp->mnt_stat.f_syncwrites++;
519 if (bp->b_lock.lk_lockholder == LK_KERNTHREAD)
520 mp->mnt_stat.f_asyncreads++;
522 mp->mnt_stat.f_syncreads++;
525 bp->b_dev = vp->v_rdev;
531 * spec_freeblks(struct vnode *a_vp, daddr_t a_addr, daddr_t a_length)
534 spec_freeblks(struct vop_freeblks_args *ap)
539 * XXX: This assumes that strategy does the deed right away.
540 * XXX: this may not be TRTTD.
542 KKASSERT(ap->a_vp->v_rdev != NULL);
543 if ((dev_dflags(ap->a_vp->v_rdev) & D_CANFREE) == 0)
545 bp = geteblk(ap->a_length);
546 bp->b_flags |= B_FREEBUF;
547 bp->b_dev = ap->a_vp->v_rdev;
548 bp->b_blkno = ap->a_addr;
549 bp->b_offset = dbtob(ap->a_addr);
550 bp->b_bcount = ap->a_length;
556 * Implement degenerate case where the block requested is the block
557 * returned, and assume that the entire device is contiguous in regards
558 * to the contiguous block range (runp and runb).
560 * spec_bmap(struct vnode *a_vp, daddr_t a_bn, struct vnode **a_vpp,
561 * daddr_t *a_bnp, int *a_runp, int *a_runb)
564 spec_bmap(struct vop_bmap_args *ap)
566 struct vnode *vp = ap->a_vp;
570 if (ap->a_vpp != NULL)
572 if (ap->a_bnp != NULL)
573 *ap->a_bnp = ap->a_bn;
574 if (vp->v_mount != NULL)
575 runp = runb = MAXBSIZE / vp->v_mount->mnt_stat.f_iosize;
576 if (ap->a_runp != NULL)
578 if (ap->a_runb != NULL)
584 * Device close routine
586 * spec_close(struct vnode *a_vp, int a_fflag, struct ucred *a_cred,
587 * struct thread *a_td)
591 spec_close(struct vop_close_args *ap)
593 struct proc *p = ap->a_td->td_proc;
594 struct vnode *vp = ap->a_vp;
595 dev_t dev = vp->v_rdev;
599 * Hack: a tty device that is a controlling terminal
600 * has a reference from the session structure.
601 * We cannot easily tell that a character device is
602 * a controlling terminal, unless it is the closing
603 * process' controlling terminal. In that case,
604 * if the reference count is 2 (this last descriptor
605 * plus the session), release the reference from the session.
607 * It is possible for v_opencount to be 0 or 1 in this case, 0
608 * because the tty might have been revoked.
612 if (vcount(vp) == 2 && vp->v_opencount <= 1 &&
613 p && vp == p->p_session->s_ttyvp) {
614 p->p_session->s_ttyvp = NULL;
619 * Vnodes can be opened and close multiple times. Do not really
620 * close the device unless (1) it is being closed forcibly,
621 * (2) the device wants to track closes, or (3) this is the last
622 * vnode doing its last close on the device.
624 * XXX the VXLOCK (force close) case can leave vnodes referencing
627 if (dev && ((vp->v_flag & VRECLAIMED) ||
628 (dev_dflags(dev) & D_TRACKCLOSE) ||
629 (vcount(vp) <= 1 && vp->v_opencount == 1))) {
630 error = dev_dclose(dev, ap->a_fflag, S_IFCHR, ap->a_td);
636 * Track the actual opens and closes on the vnode. The last close
637 * disassociates the rdev. If the rdev is already disassociated
638 * the vnode might have been revoked and no further opencount
642 KKASSERT(vp->v_opencount > 0);
644 printf("spec_close: %s %d\n",
645 dev->si_name, vp->v_opencount - 1);
647 if (--vp->v_opencount == 0)
655 * Print out the contents of a special device vnode.
657 * spec_print(struct vnode *a_vp)
660 spec_print(struct vop_print_args *ap)
662 printf("tag VT_NON, dev %s\n", devtoname(ap->a_vp->v_rdev));
667 * Special device advisory byte-level locks.
669 * spec_advlock(struct vnode *a_vp, caddr_t a_id, int a_op,
670 * struct flock *a_fl, int a_flags)
674 spec_advlock(struct vop_advlock_args *ap)
676 return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL);
680 spec_getpages_iodone(struct buf *bp)
682 bp->b_flags |= B_DONE;
687 spec_getpages(struct vop_getpages_args *ap)
691 int i, pcount, size, s;
696 int toff, nextoff, nread;
697 struct vnode *vp = ap->a_vp;
702 pcount = round_page(ap->a_count) / PAGE_SIZE;
705 * Calculate the offset of the transfer and do sanity check.
706 * FreeBSD currently only supports an 8 TB range due to b_blkno
707 * being in DEV_BSIZE ( usually 512 ) byte chunks on call to
710 offset = IDX_TO_OFF(ap->a_m[0]->pindex) + ap->a_offset;
712 #define DADDR_T_BIT (sizeof(daddr_t)*8)
713 #define OFFSET_MAX ((1LL << (DADDR_T_BIT + DEV_BSHIFT)) - 1)
715 if (offset < 0 || offset > OFFSET_MAX) {
716 /* XXX still no %q in kernel. */
717 printf("spec_getpages: preposterous offset 0x%x%08x\n",
718 (u_int)((u_quad_t)offset >> 32),
719 (u_int)(offset & 0xffffffff));
720 return (VM_PAGER_ERROR);
723 blkno = btodb(offset);
726 * Round up physical size for real devices. We cannot round using
727 * v_mount's block size data because v_mount has nothing to do with
728 * the device. i.e. it's usually '/dev'. We need the physical block
729 * size for the device itself.
731 * We can't use v_rdev->si_mountpoint because it only exists when the
732 * block device is mounted. However, we can use v_rdev.
735 if (vn_isdisk(vp, NULL))
736 blksiz = vp->v_rdev->si_bsize_phys;
740 size = (ap->a_count + blksiz - 1) & ~(blksiz - 1);
743 kva = (vm_offset_t)bp->b_data;
746 * Map the pages to be read into the kva.
748 pmap_qenter(kva, ap->a_m, pcount);
750 /* Build a minimal buffer header. */
751 bp->b_flags = B_READ | B_CALL;
752 bp->b_iodone = spec_getpages_iodone;
754 /* B_PHYS is not set, but it is nice to fill this in. */
756 bp->b_lblkno = blkno;
757 pbgetvp(ap->a_vp, bp);
759 bp->b_bufsize = size;
761 bp->b_runningbufspace = bp->b_bufsize;
762 runningbufspace += bp->b_runningbufspace;
764 mycpu->gd_cnt.v_vnodein++;
765 mycpu->gd_cnt.v_vnodepgsin += pcount;
768 VOP_STRATEGY(bp->b_vp, bp);
772 /* We definitely need to be at splbio here. */
773 while ((bp->b_flags & B_DONE) == 0) {
774 tsleep(bp, 0, "spread", 0);
779 if ((bp->b_flags & B_ERROR) != 0) {
786 nread = size - bp->b_resid;
788 if (nread < ap->a_count) {
789 bzero((caddr_t)kva + nread,
790 ap->a_count - nread);
792 pmap_qremove(kva, pcount);
796 for (i = 0, toff = 0; i < pcount; i++, toff = nextoff) {
797 nextoff = toff + PAGE_SIZE;
800 m->flags &= ~PG_ZERO;
802 if (nextoff <= nread) {
803 m->valid = VM_PAGE_BITS_ALL;
805 } else if (toff < nread) {
807 * Since this is a VM request, we have to supply the
808 * unaligned offset to allow vm_page_set_validclean()
809 * to zero sub-DEV_BSIZE'd portions of the page.
811 vm_page_set_validclean(m, 0, nread - toff);
817 if (i != ap->a_reqpage) {
819 * Just in case someone was asking for this page we
820 * now tell them that it is ok to use.
822 if (!error || (m->valid == VM_PAGE_BITS_ALL)) {
824 if (m->flags & PG_WANTED) {
827 vm_page_deactivate(m);
836 } else if (m->valid) {
839 * Since this is a VM request, we need to make the
840 * entire page presentable by zeroing invalid sections.
842 if (m->valid != VM_PAGE_BITS_ALL)
843 vm_page_zero_invalid(m, FALSE);
847 m = ap->a_m[ap->a_reqpage];
849 "spec_getpages:(%s) I/O read failure: (error=%d) bp %p vp %p\n",
850 devtoname(bp->b_dev), error, bp, bp->b_vp);
852 " size: %d, resid: %ld, a_count: %d, valid: 0x%x\n",
853 size, bp->b_resid, ap->a_count, m->valid);
855 " nread: %d, reqpage: %d, pindex: %lu, pcount: %d\n",
856 nread, ap->a_reqpage, (u_long)m->pindex, pcount);
858 * Free the buffer header back to the swap buffer pool.
861 return VM_PAGER_ERROR;
864 * Free the buffer header back to the swap buffer pool.