diff options
Diffstat (limited to 'sys/fs/specfs/spec_vnops.c')
-rw-r--r-- | sys/fs/specfs/spec_vnops.c | 780 |
1 files changed, 780 insertions, 0 deletions
diff --git a/sys/fs/specfs/spec_vnops.c b/sys/fs/specfs/spec_vnops.c new file mode 100644 index 0000000..4f8488e --- /dev/null +++ b/sys/fs/specfs/spec_vnops.c @@ -0,0 +1,780 @@ +/* + * 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 + * $FreeBSD$ + */ + +#include <sys/param.h> +#include <sys/proc.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/conf.h> +#include <sys/buf.h> +#include <sys/mount.h> +#include <sys/vnode.h> +#include <sys/stat.h> +#include <sys/fcntl.h> +#include <sys/vmmeter.h> +#include <sys/tty.h> + +#include <vm/vm.h> +#include <vm/vm_object.h> +#include <vm/vm_page.h> +#include <vm/vm_pager.h> + +static int spec_advlock __P((struct vop_advlock_args *)); +static int spec_bmap __P((struct vop_bmap_args *)); +static int spec_close __P((struct vop_close_args *)); +static int spec_freeblks __P((struct vop_freeblks_args *)); +static int spec_fsync __P((struct vop_fsync_args *)); +static int spec_getpages __P((struct vop_getpages_args *)); +static int spec_inactive __P((struct vop_inactive_args *)); +static int spec_ioctl __P((struct vop_ioctl_args *)); +static int spec_open __P((struct vop_open_args *)); +static int spec_poll __P((struct vop_poll_args *)); +static int spec_print __P((struct vop_print_args *)); +static int spec_read __P((struct vop_read_args *)); +static int spec_strategy __P((struct vop_strategy_args *)); +static int spec_write __P((struct vop_write_args *)); + +vop_t **spec_vnodeop_p; +static struct vnodeopv_entry_desc spec_vnodeop_entries[] = { + { &vop_default_desc, (vop_t *) vop_defaultop }, + { &vop_access_desc, (vop_t *) vop_ebadf }, + { &vop_advlock_desc, (vop_t *) spec_advlock }, + { &vop_bmap_desc, (vop_t *) spec_bmap }, + { &vop_close_desc, (vop_t *) spec_close }, + { &vop_create_desc, (vop_t *) vop_panic }, + { &vop_freeblks_desc, (vop_t *) spec_freeblks }, + { &vop_fsync_desc, (vop_t *) spec_fsync }, + { &vop_getpages_desc, (vop_t *) spec_getpages }, + { &vop_inactive_desc, (vop_t *) spec_inactive }, + { &vop_ioctl_desc, (vop_t *) spec_ioctl }, + { &vop_lease_desc, (vop_t *) vop_null }, + { &vop_link_desc, (vop_t *) vop_panic }, + { &vop_mkdir_desc, (vop_t *) vop_panic }, + { &vop_mknod_desc, (vop_t *) vop_panic }, + { &vop_open_desc, (vop_t *) spec_open }, + { &vop_pathconf_desc, (vop_t *) vop_stdpathconf }, + { &vop_poll_desc, (vop_t *) spec_poll }, + { &vop_print_desc, (vop_t *) spec_print }, + { &vop_read_desc, (vop_t *) spec_read }, + { &vop_readdir_desc, (vop_t *) vop_panic }, + { &vop_readlink_desc, (vop_t *) vop_panic }, + { &vop_reallocblks_desc, (vop_t *) vop_panic }, + { &vop_reclaim_desc, (vop_t *) vop_null }, + { &vop_remove_desc, (vop_t *) vop_panic }, + { &vop_rename_desc, (vop_t *) vop_panic }, + { &vop_rmdir_desc, (vop_t *) vop_panic }, + { &vop_setattr_desc, (vop_t *) vop_ebadf }, + { &vop_strategy_desc, (vop_t *) spec_strategy }, + { &vop_symlink_desc, (vop_t *) vop_panic }, + { &vop_write_desc, (vop_t *) spec_write }, + { NULL, NULL } +}; +static struct vnodeopv_desc spec_vnodeop_opv_desc = + { &spec_vnodeop_p, spec_vnodeop_entries }; + +VNODEOP_SET(spec_vnodeop_opv_desc); + +int +spec_vnoperate(ap) + struct vop_generic_args /* { + struct vnodeop_desc *a_desc; + <other random data follows, presumably> + } */ *ap; +{ + return (VOCALL(spec_vnodeop_p, ap->a_desc->vdesc_offset, ap)); +} + +static void spec_getpages_iodone __P((struct buf *bp)); + +/* + * Open a special file. + */ +/* ARGSUSED */ +static int +spec_open(ap) + struct vop_open_args /* { + struct vnode *a_vp; + int a_mode; + struct ucred *a_cred; + struct proc *a_p; + } */ *ap; +{ + struct proc *p = ap->a_p; + struct vnode *vp = ap->a_vp; + dev_t dev = vp->v_rdev; + int error; + struct cdevsw *dsw; + 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); + + dsw = devsw(dev); + if ( (dsw == NULL) || (dsw->d_open == NULL)) + return ENXIO; + + /* Make this field valid before any I/O 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) && ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { + /* + * Never allow opens for write if the device is mounted R/W + */ + if (vp->v_specmountpoint != NULL && + !(vp->v_specmountpoint->mnt_flag & MNT_RDONLY)) + return (EBUSY); + + /* + * When running in secure mode, do not allow opens + * for writing if the device is mounted + */ + if (securelevel >= 1 && vp->v_specmountpoint != NULL) + return (EPERM); + + /* + * When running in very secure mode, do not allow + * opens for writing of any devices. + */ + if (securelevel >= 2) + return (EPERM); + } + + /* XXX: Special casing of ttys for deadfs. Probably redundant */ + if (dsw->d_flags & D_TTY) + vp->v_flag |= VISTTY; + + VOP_UNLOCK(vp, 0, p); + error = (*dsw->d_open)(dev, ap->a_mode, S_IFCHR, p); + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); + + if (error) + return (error); + + if (dsw->d_flags & D_TTY) { + if (dev->si_tty) { + struct tty *tp; + tp = dev->si_tty; + if (!tp->t_stop) { + printf("Warning:%s: no t_stop, using nottystop\n", devtoname(dev)); + tp->t_stop = nottystop; + } + } + } + + if (vn_isdisk(vp)) { + if (!dev->si_bsize_phys) + dev->si_bsize_phys = DEV_BSIZE; + } + if ((dsw->d_flags & D_DISK) == 0) { + cp = devtoname(dev); + if (*cp == '#' && (dsw->d_flags & D_NAGGED) == 0) { + printf("WARNING: driver %s should register devices with make_dev() (dev_t = \"%s\")\n", + dsw->d_name, cp); + dsw->d_flags |= D_NAGGED; + } + } + return (error); +} + +/* + * Vnode op for read + */ +/* ARGSUSED */ +static int +spec_read(ap) + struct vop_read_args /* { + struct vnode *a_vp; + struct uio *a_uio; + int a_ioflag; + struct ucred *a_cred; + } */ *ap; +{ + struct vnode *vp; + struct proc *p; + struct uio *uio; + dev_t dev; + int error; + + vp = ap->a_vp; + dev = vp->v_rdev; + uio = ap->a_uio; + p = uio->uio_procp; + + if (uio->uio_resid == 0) + return (0); + + VOP_UNLOCK(vp, 0, p); + error = (*devsw(dev)->d_read) (dev, uio, ap->a_ioflag); + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); + return (error); +} + +/* + * Vnode op for write + */ +/* ARGSUSED */ +static int +spec_write(ap) + struct vop_write_args /* { + struct vnode *a_vp; + struct uio *a_uio; + int a_ioflag; + struct ucred *a_cred; + } */ *ap; +{ + struct vnode *vp; + struct proc *p; + struct uio *uio; + dev_t dev; + int error; + + vp = ap->a_vp; + dev = vp->v_rdev; + uio = ap->a_uio; + p = uio->uio_procp; + + VOP_UNLOCK(vp, 0, p); + error = (*devsw(dev)->d_write) (dev, uio, ap->a_ioflag); + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); + return (error); +} + +/* + * Device ioctl operation. + */ +/* ARGSUSED */ +static int +spec_ioctl(ap) + struct vop_ioctl_args /* { + struct vnode *a_vp; + int a_command; + caddr_t a_data; + int a_fflag; + struct ucred *a_cred; + struct proc *a_p; + } */ *ap; +{ + dev_t dev; + + dev = ap->a_vp->v_rdev; + return ((*devsw(dev)->d_ioctl)(dev, ap->a_command, + ap->a_data, ap->a_fflag, ap->a_p)); +} + +/* ARGSUSED */ +static int +spec_poll(ap) + struct vop_poll_args /* { + struct vnode *a_vp; + int a_events; + struct ucred *a_cred; + struct proc *a_p; + } */ *ap; +{ + dev_t dev; + + dev = ap->a_vp->v_rdev; + return (*devsw(dev)->d_poll)(dev, ap->a_events, ap->a_p); +} +/* + * Synch buffers associated with a block device + */ +/* ARGSUSED */ +static int +spec_fsync(ap) + struct vop_fsync_args /* { + struct vnode *a_vp; + struct ucred *a_cred; + int a_waitfor; + struct proc *a_p; + } */ *ap; +{ + struct vnode *vp = ap->a_vp; + struct buf *bp; + struct buf *nbp; + int s; + + if (!vn_isdisk(vp)) + return (0); + + /* + * Flush all dirty buffers associated with a block device. + */ +loop: + s = splbio(); + for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) { + nbp = TAILQ_NEXT(bp, b_vnbufs); + if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) + continue; + if ((bp->b_flags & B_DELWRI) == 0) + panic("spec_fsync: not dirty"); + if ((vp->v_flag & VOBJBUF) && (bp->b_flags & B_CLUSTEROK)) { + BUF_UNLOCK(bp); + vfs_bio_awrite(bp); + splx(s); + } else { + bremfree(bp); + splx(s); + bawrite(bp); + } + goto loop; + } + if (ap->a_waitfor == MNT_WAIT) { + while (vp->v_numoutput) { + vp->v_flag |= VBWAIT; + (void) tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "spfsyn", 0); + } +#ifdef DIAGNOSTIC + if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) { + vprint("spec_fsync: dirty", vp); + splx(s); + goto loop; + } +#endif + } + splx(s); + return (0); +} + +static int +spec_inactive(ap) + struct vop_inactive_args /* { + struct vnode *a_vp; + struct proc *a_p; + } */ *ap; +{ + + VOP_UNLOCK(ap->a_vp, 0, ap->a_p); + return (0); +} + +/* + * Just call the device strategy routine + */ +static int +spec_strategy(ap) + struct vop_strategy_args /* { + struct vnode *a_vp; + struct buf *a_bp; + } */ *ap; +{ + struct buf *bp; + struct vnode *vp; + struct mount *mp; + + bp = ap->a_bp; + if (((bp->b_flags & B_READ) == 0) && + (LIST_FIRST(&bp->b_dep)) != NULL && bioops.io_start) + (*bioops.io_start)(bp); + + /* + * Collect statistics on synchronous and asynchronous read + * and write counts for disks that have associated filesystems. + */ + vp = ap->a_vp; + if (vn_isdisk(vp) && (mp = vp->v_specmountpoint) != NULL) { + if ((bp->b_flags & B_READ) == 0) { + if (bp->b_lock.lk_lockholder == LK_KERNPROC) + mp->mnt_stat.f_asyncwrites++; + else + mp->mnt_stat.f_syncwrites++; + } else { + if (bp->b_lock.lk_lockholder == LK_KERNPROC) + mp->mnt_stat.f_asyncreads++; + else + mp->mnt_stat.f_syncreads++; + } + } + KASSERT(devsw(bp->b_dev) != NULL, + ("No devsw on dev %s responsible for buffer %p\n", + devtoname(bp->b_dev), bp)); + KASSERT(devsw(bp->b_dev)->d_strategy != NULL, + ("No strategy on dev %s responsible for buffer %p\n", + devtoname(bp->b_dev), bp)); + BUF_STRATEGY(bp, 0); + return (0); +} + +static int +spec_freeblks(ap) + struct vop_freeblks_args /* { + struct vnode *a_vp; + daddr_t a_addr; + daddr_t a_length; + } */ *ap; +{ + struct cdevsw *bsw; + struct buf *bp; + + /* + * XXX: This assumes that strategy does the deed right away. + * XXX: this may not be TRTTD. + */ + bsw = devsw(ap->a_vp->v_rdev); + if ((bsw->d_flags & D_CANFREE) == 0) + return (0); + bp = geteblk(ap->a_length); + bp->b_flags |= B_FREEBUF; + bp->b_dev = ap->a_vp->v_rdev; + bp->b_blkno = ap->a_addr; + bp->b_offset = dbtob(ap->a_addr); + bp->b_bcount = ap->a_length; + BUF_STRATEGY(bp, 0); + 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). + */ +static int +spec_bmap(ap) + struct vop_bmap_args /* { + struct vnode *a_vp; + daddr_t a_bn; + struct vnode **a_vpp; + daddr_t *a_bnp; + int *a_runp; + int *a_runb; + } */ *ap; +{ + struct vnode *vp = ap->a_vp; + int runp = 0; + int runb = 0; + + if (ap->a_vpp != NULL) + *ap->a_vpp = vp; + if (ap->a_bnp != NULL) + *ap->a_bnp = ap->a_bn; + if (vp->v_mount != NULL) + runp = runb = MAXBSIZE / vp->v_mount->mnt_stat.f_iosize; + if (ap->a_runp != NULL) + *ap->a_runp = runp; + if (ap->a_runb != NULL) + *ap->a_runb = runb; + return (0); +} + +/* + * Device close routine + */ +/* ARGSUSED */ +static int +spec_close(ap) + struct vop_close_args /* { + struct vnode *a_vp; + int a_fflag; + struct ucred *a_cred; + struct proc *a_p; + } */ *ap; +{ + struct vnode *vp = ap->a_vp; + struct proc *p = ap->a_p; + dev_t dev = vp->v_rdev; + + /* + * 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. + */ + if (vcount(vp) == 2 && p && (vp->v_flag & VXLOCK) == 0 && + vp == p->p_session->s_ttyvp) { + vrele(vp); + p->p_session->s_ttyvp = NULL; + } + /* + * We do not want to really close the device if it + * is still in use unless we are trying to close it + * forcibly. Since every use (buffer, vnode, swap, cmap) + * holds a reference to the vnode, and because we mark + * any other vnodes that alias this device, when the + * sum of the reference counts on all the aliased + * vnodes descends to one, we are on last close. + */ + if (vp->v_flag & VXLOCK) { + /* Forced close */ + } else if (devsw(dev)->d_flags & D_TRACKCLOSE) { + /* Keep device updated on status */ + } else if (vcount(vp) > 1) { + return (0); + } + return (devsw(dev)->d_close(dev, ap->a_fflag, S_IFCHR, p)); +} + +/* + * Print out the contents of a special device vnode. + */ +static int +spec_print(ap) + struct vop_print_args /* { + struct vnode *a_vp; + } */ *ap; +{ + + printf("tag VT_NON, dev %s\n", devtoname(ap->a_vp->v_rdev)); + return (0); +} + +/* + * Special device advisory byte-level locks. + */ +/* ARGSUSED */ +static int +spec_advlock(ap) + struct vop_advlock_args /* { + struct vnode *a_vp; + caddr_t a_id; + int a_op; + struct flock *a_fl; + int a_flags; + } */ *ap; +{ + + return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL); +} + +static void +spec_getpages_iodone(bp) + struct buf *bp; +{ + + bp->b_flags |= B_DONE; + wakeup(bp); +} + +static int +spec_getpages(ap) + struct vop_getpages_args *ap; +{ + vm_offset_t kva; + int error; + int i, pcount, size, s; + daddr_t blkno; + 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. + * FreeBSD currently only supports an 8 TB range due to b_blkno + * being in DEV_BSIZE ( usually 512 ) byte chunks on call to + * VOP_STRATEGY. XXX + */ + offset = IDX_TO_OFF(ap->a_m[0]->pindex) + ap->a_offset; + +#define DADDR_T_BIT (sizeof(daddr_t)*8) +#define OFFSET_MAX ((1LL << (DADDR_T_BIT + DEV_BSHIFT)) - 1) + + if (offset < 0 || offset > OFFSET_MAX) { + /* XXX still no %q in kernel. */ + printf("spec_getpages: preposterous offset 0x%x%08x\n", + (u_int)((u_quad_t)offset >> 32), + (u_int)(offset & 0xffffffff)); + return (VM_PAGER_ERROR); + } + + blkno = btodb(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_specmountpoint because it only exists when the + * block device is mounted. However, we can use v_rdev. + */ + + if (vn_isdisk(vp)) + 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_flags = B_READ | B_CALL; + bp->b_iodone = spec_getpages_iodone; + + /* B_PHYS is not set, but it is nice to fill this in. */ + bp->b_rcred = bp->b_wcred = curproc->p_ucred; + if (bp->b_rcred != NOCRED) + crhold(bp->b_rcred); + if (bp->b_wcred != NOCRED) + crhold(bp->b_wcred); + bp->b_blkno = blkno; + bp->b_lblkno = blkno; + pbgetvp(ap->a_vp, bp); + bp->b_bcount = size; + bp->b_bufsize = size; + bp->b_resid = 0; + + cnt.v_vnodein++; + cnt.v_vnodepgsin += pcount; + + /* Do the input. */ + VOP_STRATEGY(bp->b_vp, bp); + + s = splbio(); + + /* We definitely need to be at splbio here. */ + while ((bp->b_flags & B_DONE) == 0) + tsleep(bp, PVM, "spread", 0); + + splx(s); + + if ((bp->b_flags & B_ERROR) != 0) { + if (bp->b_error) + error = bp->b_error; + else + error = EIO; + } + + nread = size - 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]; +#ifndef MAX_PERF + printf( + "spec_getpages:(%s) I/O read failure: (error=%d) bp %p vp %p\n", + devtoname(bp->b_dev), error, bp, bp->b_vp); + printf( + " size: %d, resid: %ld, a_count: %d, valid: 0x%x\n", + size, bp->b_resid, ap->a_count, m->valid); + printf( + " nread: %d, reqpage: %d, pindex: %lu, pcount: %d\n", + nread, ap->a_reqpage, (u_long)m->pindex, pcount); +#endif + /* + * 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; +} |