/* * Copyright (c) 1989, 1993, 1995 * The Regents of the University of California. All rights reserved. * * 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. * * @(#)spec_vnops.c 8.14 (Berkeley) 5/21/95 * $FreeBSD: src/sys/miscfs/specfs/spec_vnops.c,v 1.131.2.4 2001/02/26 04:23:20 jlemon Exp $ * $DragonFly: src/sys/vfs/specfs/spec_vnops.c,v 1.57 2007/11/06 03:50:02 dillon Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Specfs chained debugging (bitmask) * * 0 - disable debugging * 1 - report chained I/Os * 2 - force 4K chained I/Os */ #define SPEC_CHAIN_DEBUG 0 static int spec_advlock (struct vop_advlock_args *); static int spec_bmap (struct vop_bmap_args *); static int spec_close (struct vop_close_args *); static int spec_freeblks (struct vop_freeblks_args *); static int spec_fsync (struct vop_fsync_args *); static int spec_getpages (struct vop_getpages_args *); static int spec_inactive (struct vop_inactive_args *); static int spec_ioctl (struct vop_ioctl_args *); static int spec_open (struct vop_open_args *); static int spec_poll (struct vop_poll_args *); static int spec_kqfilter (struct vop_kqfilter_args *); static int spec_print (struct vop_print_args *); static int spec_read (struct vop_read_args *); static int spec_strategy (struct vop_strategy_args *); static int spec_write (struct vop_write_args *); static void spec_strategy_done(struct bio *nbio); struct vop_ops spec_vnode_vops = { .vop_default = vop_defaultop, .vop_access = (void *)vop_ebadf, .vop_advlock = spec_advlock, .vop_bmap = spec_bmap, .vop_close = spec_close, .vop_old_create = (void *)vop_panic, .vop_freeblks = spec_freeblks, .vop_fsync = spec_fsync, .vop_getpages = spec_getpages, .vop_inactive = spec_inactive, .vop_ioctl = spec_ioctl, .vop_old_link = (void *)vop_panic, .vop_old_mkdir = (void *)vop_panic, .vop_old_mknod = (void *)vop_panic, .vop_open = spec_open, .vop_pathconf = vop_stdpathconf, .vop_poll = spec_poll, .vop_kqfilter = spec_kqfilter, .vop_print = spec_print, .vop_read = spec_read, .vop_readdir = (void *)vop_panic, .vop_readlink = (void *)vop_panic, .vop_reallocblks = (void *)vop_panic, .vop_reclaim = (void *)vop_null, .vop_old_remove = (void *)vop_panic, .vop_old_rename = (void *)vop_panic, .vop_old_rmdir = (void *)vop_panic, .vop_setattr = (void *)vop_ebadf, .vop_strategy = spec_strategy, .vop_old_symlink = (void *)vop_panic, .vop_write = spec_write }; struct vop_ops *spec_vnode_vops_p = &spec_vnode_vops; VNODEOP_SET(spec_vnode_vops); extern int dev_ref_debug; /* * spec_vnoperate() */ int spec_vnoperate(struct vop_generic_args *ap) { return (VOCALL(&spec_vnode_vops, ap)); } static void spec_getpages_iodone (struct bio *bio); /* * Open a special file. * * spec_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred, * struct file *a_fp) */ /* ARGSUSED */ static int spec_open(struct vop_open_args *ap) { struct vnode *vp = ap->a_vp; cdev_t dev; int error; const char *cp; /* * Don't allow open if fs is mounted -nodev. */ if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) return (ENXIO); if (vp->v_type == VBLK) return (ENXIO); /* * Resolve the device. If the vnode is already open v_rdev may * already be resolved. However, if the device changes out from * under us we report it (and, for now, we allow it). Since * v_release_rdev() zero's v_opencount, we have to save and restore * it when replacing the rdev reference. */ if (vp->v_rdev != NULL) { dev = get_dev(vp->v_umajor, vp->v_uminor); if (dev != vp->v_rdev) { int oc = vp->v_opencount; kprintf( "Warning: spec_open: dev %s was lost", vp->v_rdev->si_name); v_release_rdev(vp); error = v_associate_rdev(vp, get_dev(vp->v_umajor, vp->v_uminor)); if (error) { kprintf(", reacquisition failed\n"); } else { vp->v_opencount = oc; kprintf(", reacquisition successful\n"); } } else { error = 0; } } else { error = v_associate_rdev(vp, get_dev(vp->v_umajor, vp->v_uminor)); } if (error) return(error); /* * Prevent degenerate open/close sequences from nulling out rdev. */ dev = vp->v_rdev; KKASSERT(dev != NULL); /* * Make this field valid before any I/O in ->d_open. XXX the * device itself should probably be required to initialize * this field in d_open. */ if (!dev->si_iosize_max) dev->si_iosize_max = DFLTPHYS; /* * XXX: Disks get special billing here, but it is mostly wrong. * XXX: diskpartitions can overlap and the real checks should * XXX: take this into account, and consequently they need to * XXX: live in the diskslicing code. Some checks do. */ if (vn_isdisk(vp, NULL) && ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { /* * Never allow opens for write if the device is mounted R/W */ if (vp->v_rdev && vp->v_rdev->si_mountpoint && !(vp->v_rdev->si_mountpoint->mnt_flag & MNT_RDONLY)) { error = EBUSY; goto done; } /* * When running in secure mode, do not allow opens * for writing if the device is mounted */ if (securelevel >= 1 && vfs_mountedon(vp)) { error = EPERM; goto done; } /* * When running in very secure mode, do not allow * opens for writing of any devices. */ if (securelevel >= 2) { error = EPERM; goto done; } } /* XXX: Special casing of ttys for deadfs. Probably redundant */ if (dev_dflags(dev) & D_TTY) vp->v_flag |= VISTTY; /* * dev_dopen() is always called for each open. dev_dclose() is * only called for the last close unless D_TRACKCLOSE is set. */ vn_unlock(vp); error = dev_dopen(dev, ap->a_mode, S_IFCHR, ap->a_cred); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (error) goto done; if (dev_dflags(dev) & D_TTY) { if (dev->si_tty) { struct tty *tp; tp = dev->si_tty; if (!tp->t_stop) { kprintf("Warning:%s: no t_stop, using nottystop\n", devtoname(dev)); tp->t_stop = nottystop; } } } /* * If this is 'disk' or disk-like device, associate a VM object * with it. */ if (vn_isdisk(vp, NULL)) { if (!dev->si_bsize_phys) dev->si_bsize_phys = DEV_BSIZE; vinitvmio(vp, IDX_TO_OFF(INT_MAX)); } if ((dev_dflags(dev) & D_DISK) == 0) { cp = devtoname(dev); if (*cp == '#') { kprintf("WARNING: driver %s should register devices with make_dev() (cdev_t = \"%s\")\n", dev_dname(dev), cp); } } /* * If we were handed a file pointer we may be able to install a * shortcut which issues device read and write operations directly * from the fileops rather then having to go through spec_read() * and spec_write(). */ if (ap->a_fp) vn_setspecops(ap->a_fp); if (dev_ref_debug) kprintf("spec_open: %s %d\n", dev->si_name, vp->v_opencount); done: if (error) { if (vp->v_opencount == 0) v_release_rdev(vp); } else { vop_stdopen(ap); } return (error); } /* * Vnode op for read * * spec_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, * struct ucred *a_cred) */ /* ARGSUSED */ static int spec_read(struct vop_read_args *ap) { struct vnode *vp; struct thread *td; struct uio *uio; cdev_t dev; int error; vp = ap->a_vp; dev = vp->v_rdev; uio = ap->a_uio; td = uio->uio_td; if (dev == NULL) /* device was revoked */ return (EBADF); if (uio->uio_resid == 0) return (0); vn_unlock(vp); error = dev_dread(dev, uio, ap->a_ioflag); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); return (error); } /* * Vnode op for write * * spec_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, * struct ucred *a_cred) */ /* ARGSUSED */ static int spec_write(struct vop_write_args *ap) { struct vnode *vp; struct thread *td; struct uio *uio; cdev_t dev; int error; vp = ap->a_vp; dev = vp->v_rdev; uio = ap->a_uio; td = uio->uio_td; KKASSERT(uio->uio_segflg != UIO_NOCOPY); if (dev == NULL) /* device was revoked */ return (EBADF); vn_unlock(vp); error = dev_dwrite(dev, uio, ap->a_ioflag); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); return (error); } /* * Device ioctl operation. * * spec_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data, * int a_fflag, struct ucred *a_cred) */ /* ARGSUSED */ static int spec_ioctl(struct vop_ioctl_args *ap) { cdev_t dev; if ((dev = ap->a_vp->v_rdev) == NULL) return (EBADF); /* device was revoked */ return (dev_dioctl(dev, ap->a_command, ap->a_data, ap->a_fflag, ap->a_cred)); } /* * spec_poll(struct vnode *a_vp, int a_events, struct ucred *a_cred) */ /* ARGSUSED */ static int spec_poll(struct vop_poll_args *ap) { cdev_t dev; if ((dev = ap->a_vp->v_rdev) == NULL) return (EBADF); /* device was revoked */ return (dev_dpoll(dev, ap->a_events)); } /* * spec_kqfilter(struct vnode *a_vp, struct knote *a_kn) */ /* ARGSUSED */ static int spec_kqfilter(struct vop_kqfilter_args *ap) { cdev_t dev; if ((dev = ap->a_vp->v_rdev) == NULL) return (EBADF); /* device was revoked */ return (dev_dkqfilter(dev, ap->a_kn)); } /* * Synch buffers associated with a block device * * spec_fsync(struct vnode *a_vp, int a_waitfor) */ /* ARGSUSED */ static int spec_fsync(struct vop_fsync_args *ap) { struct vnode *vp = ap->a_vp; int error; if (!vn_isdisk(vp, NULL)) return (0); /* * Flush all dirty buffers associated with a block device. */ error = vfsync(vp, ap->a_waitfor, 10000, NULL, NULL); return (error); } /* * spec_inactive(struct vnode *a_vp) */ static int spec_inactive(struct vop_inactive_args *ap) { return (0); } /* * Convert a vnode strategy call into a device strategy call. Vnode strategy * calls are not limited to device DMA limits so we have to deal with the * case. * * spec_strategy(struct vnode *a_vp, struct bio *a_bio) */ static int spec_strategy(struct vop_strategy_args *ap) { struct bio *bio = ap->a_bio; struct buf *bp = bio->bio_buf; struct buf *nbp; struct vnode *vp; struct mount *mp; int chunksize; int maxiosize; if (bp->b_cmd != BUF_CMD_READ && LIST_FIRST(&bp->b_dep) != NULL) buf_start(bp); /* * Collect statistics on synchronous and asynchronous read * and write counts for disks that have associated filesystems. */ vp = ap->a_vp; KKASSERT(vp->v_rdev != NULL); /* XXX */ if (vn_isdisk(vp, NULL) && (mp = vp->v_rdev->si_mountpoint) != NULL) { if (bp->b_cmd == BUF_CMD_READ) { if (bp->b_flags & B_ASYNC) mp->mnt_stat.f_asyncreads++; else mp->mnt_stat.f_syncreads++; } else { if (bp->b_flags & B_ASYNC) mp->mnt_stat.f_asyncwrites++; else mp->mnt_stat.f_syncwrites++; } } /* * Device iosize limitations only apply to read and write. Shortcut * the I/O if it fits. */ if ((maxiosize = vp->v_rdev->si_iosize_max) == 0) { kprintf("%s: si_iosize_max not set!\n", dev_dname(vp->v_rdev)); maxiosize = MAXPHYS; } #if SPEC_CHAIN_DEBUG & 2 maxiosize = 4096; #endif if (bp->b_bcount <= maxiosize || (bp->b_cmd != BUF_CMD_READ && bp->b_cmd != BUF_CMD_WRITE)) { dev_dstrategy_chain(vp->v_rdev, bio); return (0); } /* * Clone the buffer and set up an I/O chain to chunk up the I/O. */ nbp = kmalloc(sizeof(*bp), M_DEVBUF, M_INTWAIT|M_ZERO); initbufbio(nbp); buf_dep_init(nbp); BUF_LOCKINIT(nbp); BUF_LOCK(nbp, LK_EXCLUSIVE); BUF_KERNPROC(nbp); nbp->b_vp = vp; nbp->b_flags = B_PAGING | (bp->b_flags & B_BNOCLIP); nbp->b_data = bp->b_data; nbp->b_bio1.bio_done = spec_strategy_done; nbp->b_bio1.bio_offset = bio->bio_offset; nbp->b_bio1.bio_caller_info1.ptr = bio; /* * Start the first transfer */ if (vn_isdisk(vp, NULL)) chunksize = vp->v_rdev->si_bsize_phys; else chunksize = DEV_BSIZE; chunksize = maxiosize / chunksize * chunksize; #if SPEC_CHAIN_DEBUG & 1 kprintf("spec_strategy chained I/O chunksize=%d\n", chunksize); #endif nbp->b_cmd = bp->b_cmd; nbp->b_bcount = chunksize; nbp->b_bufsize = chunksize; /* used to detect a short I/O */ nbp->b_bio1.bio_caller_info2.index = chunksize; #if SPEC_CHAIN_DEBUG & 1 kprintf("spec_strategy: chain %p offset %d/%d bcount %d\n", bp, 0, bp->b_bcount, nbp->b_bcount); #endif dev_dstrategy(vp->v_rdev, &nbp->b_bio1); return (0); } /* * Chunked up transfer completion routine - chain transfers until done */ static void spec_strategy_done(struct bio *nbio) { struct buf *nbp = nbio->bio_buf; struct bio *bio = nbio->bio_caller_info1.ptr; /* original bio */ struct buf *bp = bio->bio_buf; /* original bp */ int chunksize = nbio->bio_caller_info2.index; /* chunking */ int boffset = nbp->b_data - bp->b_data; if (nbp->b_flags & B_ERROR) { /* * An error terminates the chain, propogate the error back * to the original bp */ bp->b_flags |= B_ERROR; bp->b_error = nbp->b_error; bp->b_resid = bp->b_bcount - boffset + (nbp->b_bcount - nbp->b_resid); #if SPEC_CHAIN_DEBUG & 1 kprintf("spec_strategy: chain %p error %d bcount %d/%d\n", bp, bp->b_error, bp->b_bcount, bp->b_bcount - bp->b_resid); #endif kfree(nbp, M_DEVBUF); biodone(bio); } else if (nbp->b_resid) { /* * A short read or write terminates the chain */ bp->b_error = nbp->b_error; bp->b_resid = bp->b_bcount - boffset + (nbp->b_bcount - nbp->b_resid); #if SPEC_CHAIN_DEBUG & 1 kprintf("spec_strategy: chain %p short read(1) bcount %d/%d\n", bp, bp->b_bcount - bp->b_resid, bp->b_bcount); #endif kfree(nbp, M_DEVBUF); biodone(bio); } else if (nbp->b_bcount != nbp->b_bufsize) { /* * A short read or write can also occur by truncating b_bcount */ #if SPEC_CHAIN_DEBUG & 1 kprintf("spec_strategy: chain %p short read(2) bcount %d/%d\n", bp, nbp->b_bcount + boffset, bp->b_bcount); #endif bp->b_error = 0; bp->b_bcount = nbp->b_bcount + boffset; bp->b_resid = nbp->b_resid; kfree(nbp, M_DEVBUF); biodone(bio); } else if (nbp->b_bcount + boffset == bp->b_bcount) { /* * No more data terminates the chain */ #if SPEC_CHAIN_DEBUG & 1 kprintf("spec_strategy: chain %p finished bcount %d\n", bp, bp->b_bcount); #endif bp->b_error = 0; bp->b_resid = 0; kfree(nbp, M_DEVBUF); biodone(bio); } else { /* * Continue the chain */ boffset += nbp->b_bcount; nbp->b_data = bp->b_data + boffset; nbp->b_bcount = bp->b_bcount - boffset; if (nbp->b_bcount > chunksize) nbp->b_bcount = chunksize; nbp->b_bio1.bio_done = spec_strategy_done; nbp->b_bio1.bio_offset = bio->bio_offset + boffset; #if SPEC_CHAIN_DEBUG & 1 kprintf("spec_strategy: chain %p offset %d/%d bcount %d\n", bp, boffset, bp->b_bcount, nbp->b_bcount); #endif dev_dstrategy(nbp->b_vp->v_rdev, &nbp->b_bio1); } } /* * spec_freeblks(struct vnode *a_vp, daddr_t a_addr, daddr_t a_length) */ static int spec_freeblks(struct vop_freeblks_args *ap) { struct buf *bp; /* * XXX: This assumes that strategy does the deed right away. * XXX: this may not be TRTTD. */ KKASSERT(ap->a_vp->v_rdev != NULL); if ((dev_dflags(ap->a_vp->v_rdev) & D_CANFREE) == 0) return (0); bp = geteblk(ap->a_length); bp->b_cmd = BUF_CMD_FREEBLKS; bp->b_bio1.bio_offset = ap->a_offset; bp->b_bcount = ap->a_length; dev_dstrategy(ap->a_vp->v_rdev, &bp->b_bio1); return (0); } /* * Implement degenerate case where the block requested is the block * returned, and assume that the entire device is contiguous in regards * to the contiguous block range (runp and runb). * * spec_bmap(struct vnode *a_vp, off_t a_loffset, * off_t *a_doffsetp, int *a_runp, int *a_runb) */ static int spec_bmap(struct vop_bmap_args *ap) { if (ap->a_doffsetp != NULL) *ap->a_doffsetp = ap->a_loffset; if (ap->a_runp != NULL) *ap->a_runp = MAXBSIZE; if (ap->a_runb != NULL) { if (ap->a_loffset < MAXBSIZE) *ap->a_runb = (int)ap->a_loffset; else *ap->a_runb = MAXBSIZE; } return (0); } /* * Device close routine * * spec_close(struct vnode *a_vp, int a_fflag) * * NOTE: the vnode may or may not be locked on call. */ /* ARGSUSED */ static int spec_close(struct vop_close_args *ap) { struct proc *p = curproc; struct vnode *vp = ap->a_vp; cdev_t dev = vp->v_rdev; int error; int needrelock; /* * Hack: a tty device that is a controlling terminal * has a reference from the session structure. * We cannot easily tell that a character device is * a controlling terminal, unless it is the closing * process' controlling terminal. In that case, * if the reference count is 2 (this last descriptor * plus the session), release the reference from the session. * * It is possible for v_opencount to be 0 or 1 in this case, 0 * because the tty might have been revoked. */ if (dev) reference_dev(dev); if (vcount(vp) == 2 && vp->v_opencount <= 1 && p && vp == p->p_session->s_ttyvp) { p->p_session->s_ttyvp = NULL; vrele(vp); } /* * Vnodes can be opened and close multiple times. Do not really * close the device unless (1) it is being closed forcibly, * (2) the device wants to track closes, or (3) this is the last * vnode doing its last close on the device. * * XXX the VXLOCK (force close) case can leave vnodes referencing * a closed device. */ if (dev && ((vp->v_flag & VRECLAIMED) || (dev_dflags(dev) & D_TRACKCLOSE) || (vcount(vp) <= 1 && vp->v_opencount == 1))) { needrelock = 0; if (vn_islocked(vp)) { needrelock = 1; vn_unlock(vp); } error = dev_dclose(dev, ap->a_fflag, S_IFCHR); if (needrelock) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); } else { error = 0; } /* * Track the actual opens and closes on the vnode. The last close * disassociates the rdev. If the rdev is already disassociated * the vnode might have been revoked and no further opencount * tracking occurs. */ if (dev) { /*KKASSERT(vp->v_opencount > 0);*/ if (dev_ref_debug) { kprintf("spec_close: %s %d\n", dev->si_name, vp->v_opencount - 1); } if (vp->v_opencount == 1) v_release_rdev(vp); release_dev(dev); } vop_stdclose(ap); return(error); } /* * Print out the contents of a special device vnode. * * spec_print(struct vnode *a_vp) */ static int spec_print(struct vop_print_args *ap) { kprintf("tag VT_NON, dev %s\n", devtoname(ap->a_vp->v_rdev)); return (0); } /* * Special device advisory byte-level locks. * * spec_advlock(struct vnode *a_vp, caddr_t a_id, int a_op, * struct flock *a_fl, int a_flags) */ /* ARGSUSED */ static int spec_advlock(struct vop_advlock_args *ap) { return ((ap->a_flags & F_POSIX) ? EINVAL : EOPNOTSUPP); } static void spec_getpages_iodone(struct bio *bio) { bio->bio_buf->b_cmd = BUF_CMD_DONE; wakeup(bio->bio_buf); } /* * spec_getpages() - get pages associated with device vnode. * * Note that spec_read and spec_write do not use the buffer cache, so we * must fully implement getpages here. */ static int spec_getpages(struct vop_getpages_args *ap) { vm_offset_t kva; int error; int i, pcount, size; struct buf *bp; vm_page_t m; vm_ooffset_t offset; int toff, nextoff, nread; struct vnode *vp = ap->a_vp; int blksiz; int gotreqpage; error = 0; pcount = round_page(ap->a_count) / PAGE_SIZE; /* * Calculate the offset of the transfer and do sanity check. */ offset = IDX_TO_OFF(ap->a_m[0]->pindex) + ap->a_offset; /* * Round up physical size for real devices. We cannot round using * v_mount's block size data because v_mount has nothing to do with * the device. i.e. it's usually '/dev'. We need the physical block * size for the device itself. * * We can't use v_rdev->si_mountpoint because it only exists when the * block device is mounted. However, we can use v_rdev. */ if (vn_isdisk(vp, NULL)) blksiz = vp->v_rdev->si_bsize_phys; else blksiz = DEV_BSIZE; size = (ap->a_count + blksiz - 1) & ~(blksiz - 1); bp = getpbuf(NULL); kva = (vm_offset_t)bp->b_data; /* * Map the pages to be read into the kva. */ pmap_qenter(kva, ap->a_m, pcount); /* Build a minimal buffer header. */ bp->b_cmd = BUF_CMD_READ; bp->b_bcount = size; bp->b_resid = 0; bp->b_runningbufspace = size; runningbufspace += bp->b_runningbufspace; bp->b_bio1.bio_offset = offset; bp->b_bio1.bio_done = spec_getpages_iodone; mycpu->gd_cnt.v_vnodein++; mycpu->gd_cnt.v_vnodepgsin += pcount; /* Do the input. */ vn_strategy(ap->a_vp, &bp->b_bio1); crit_enter(); /* We definitely need to be at splbio here. */ while (bp->b_cmd != BUF_CMD_DONE) tsleep(bp, 0, "spread", 0); crit_exit(); if (bp->b_flags & B_ERROR) { if (bp->b_error) error = bp->b_error; else error = EIO; } /* * If EOF is encountered we must zero-extend the result in order * to ensure that the page does not contain garabge. When no * error occurs, an early EOF is indicated if b_bcount got truncated. * b_resid is relative to b_bcount and should be 0, but some devices * might indicate an EOF with b_resid instead of truncating b_bcount. */ nread = bp->b_bcount - bp->b_resid; if (nread < ap->a_count) bzero((caddr_t)kva + nread, ap->a_count - nread); pmap_qremove(kva, pcount); gotreqpage = 0; for (i = 0, toff = 0; i < pcount; i++, toff = nextoff) { nextoff = toff + PAGE_SIZE; m = ap->a_m[i]; m->flags &= ~PG_ZERO; if (nextoff <= nread) { m->valid = VM_PAGE_BITS_ALL; vm_page_undirty(m); } else if (toff < nread) { /* * Since this is a VM request, we have to supply the * unaligned offset to allow vm_page_set_validclean() * to zero sub-DEV_BSIZE'd portions of the page. */ vm_page_set_validclean(m, 0, nread - toff); } else { m->valid = 0; vm_page_undirty(m); } if (i != ap->a_reqpage) { /* * Just in case someone was asking for this page we * now tell them that it is ok to use. */ if (!error || (m->valid == VM_PAGE_BITS_ALL)) { if (m->valid) { if (m->flags & PG_WANTED) { vm_page_activate(m); } else { vm_page_deactivate(m); } vm_page_wakeup(m); } else { vm_page_free(m); } } else { vm_page_free(m); } } else if (m->valid) { gotreqpage = 1; /* * Since this is a VM request, we need to make the * entire page presentable by zeroing invalid sections. */ if (m->valid != VM_PAGE_BITS_ALL) vm_page_zero_invalid(m, FALSE); } } if (!gotreqpage) { m = ap->a_m[ap->a_reqpage]; kprintf( "spec_getpages:(%s) I/O read failure: (error=%d) bp %p vp %p\n", devtoname(vp->v_rdev), error, bp, bp->b_vp); kprintf( " size: %d, resid: %d, a_count: %d, valid: 0x%x\n", size, bp->b_resid, ap->a_count, m->valid); kprintf( " nread: %d, reqpage: %d, pindex: %lu, pcount: %d\n", nread, ap->a_reqpage, (u_long)m->pindex, pcount); /* * Free the buffer header back to the swap buffer pool. */ relpbuf(bp, NULL); return VM_PAGER_ERROR; } /* * Free the buffer header back to the swap buffer pool. */ relpbuf(bp, NULL); return VM_PAGER_OK; }