Annotation of Net2/ufs/mfs_vnops.c, revision 1.1.1.2

1.1       root        1: /*
                      2:  * Copyright (c) 1989 The Regents of the University of California.
                      3:  * All rights reserved.
                      4:  *
                      5:  * Redistribution and use in source and binary forms, with or without
                      6:  * modification, are permitted provided that the following conditions
                      7:  * are met:
                      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
                     11:  *    notice, this list of conditions and the following disclaimer in the
                     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
                     16:  *     California, Berkeley and its contributors.
                     17:  * 4. Neither the name of the University nor the names of its contributors
                     18:  *    may be used to endorse or promote products derived from this software
                     19:  *    without specific prior written permission.
                     20:  *
                     21:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     22:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     23:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     24:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     25:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     26:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     27:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     28:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     29:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     30:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     31:  * SUCH DAMAGE.
                     32:  *
                     33:  *     @(#)mfs_vnops.c 7.22 (Berkeley) 4/16/91
                     34:  */
                     35: 
                     36: #include "param.h"
                     37: #include "systm.h"
                     38: #include "time.h"
                     39: #include "kernel.h"
                     40: #include "proc.h"
                     41: #include "buf.h"
                     42: #include "vnode.h"
                     43: 
                     44: #include "mfsnode.h"
                     45: #include "mfsiom.h"
                     46: 
                     47: #include "machine/vmparam.h"
                     48: 
                     49: /*
                     50:  * mfs vnode operations.
                     51:  */
                     52: struct vnodeops mfs_vnodeops = {
                     53:        mfs_lookup,             /* lookup */
                     54:        mfs_create,             /* create */
                     55:        mfs_mknod,              /* mknod */
                     56:        mfs_open,               /* open */
                     57:        mfs_close,              /* close */
                     58:        mfs_access,             /* access */
                     59:        mfs_getattr,            /* getattr */
                     60:        mfs_setattr,            /* setattr */
                     61:        mfs_read,               /* read */
                     62:        mfs_write,              /* write */
                     63:        mfs_ioctl,              /* ioctl */
                     64:        mfs_select,             /* select */
                     65:        mfs_mmap,               /* mmap */
                     66:        mfs_fsync,              /* fsync */
                     67:        mfs_seek,               /* seek */
                     68:        mfs_remove,             /* remove */
                     69:        mfs_link,               /* link */
                     70:        mfs_rename,             /* rename */
                     71:        mfs_mkdir,              /* mkdir */
                     72:        mfs_rmdir,              /* rmdir */
                     73:        mfs_symlink,            /* symlink */
                     74:        mfs_readdir,            /* readdir */
                     75:        mfs_readlink,           /* readlink */
                     76:        mfs_abortop,            /* abortop */
                     77:        mfs_inactive,           /* inactive */
                     78:        mfs_reclaim,            /* reclaim */
                     79:        mfs_lock,               /* lock */
                     80:        mfs_unlock,             /* unlock */
                     81:        mfs_bmap,               /* bmap */
                     82:        mfs_strategy,           /* strategy */
                     83:        mfs_print,              /* print */
                     84:        mfs_islocked,           /* islocked */
                     85:        mfs_advlock,            /* advlock */
                     86: };
                     87: 
                     88: /*
                     89:  * Vnode Operations.
                     90:  *
                     91:  * Open called to allow memory filesystem to initialize and
                     92:  * validate before actual IO. Record our process identifier
                     93:  * so we can tell when we are doing I/O to ourself.
                     94:  */
                     95: /* ARGSUSED */
                     96: mfs_open(vp, mode, cred, p)
                     97:        register struct vnode *vp;
                     98:        int mode;
                     99:        struct ucred *cred;
                    100:        struct proc *p;
                    101: {
                    102: 
                    103:        if (vp->v_type != VBLK) {
                    104:                panic("mfs_ioctl not VBLK");
                    105:                /* NOTREACHED */
                    106:        }
                    107:        return (0);
                    108: }
                    109: 
                    110: /*
                    111:  * Ioctl operation.
                    112:  */
                    113: /* ARGSUSED */
                    114: mfs_ioctl(vp, com, data, fflag, cred, p)
                    115:        struct vnode *vp;
                    116:        int com;
                    117:        caddr_t data;
                    118:        int fflag;
                    119:        struct ucred *cred;
                    120:        struct proc *p;
                    121: {
                    122: 
                    123:        return (-1);
                    124: }
                    125: 
                    126: /*
                    127:  * Pass I/O requests to the memory filesystem process.
                    128:  */
                    129: mfs_strategy(bp)
                    130:        register struct buf *bp;
                    131: {
                    132:        register struct mfsnode *mfsp;
                    133:        struct vnode *vp;
                    134:        struct proc *p = curproc;               /* XXX */
                    135: 
                    136:        if (vfinddev(bp->b_dev, VBLK, &vp) || vp->v_usecount == 0)
                    137:                panic("mfs_strategy: bad dev");
                    138:        mfsp = VTOMFS(vp);
                    139:        if (mfsp->mfs_pid == p->p_pid) {
                    140:                mfs_doio(bp, mfsp->mfs_baseoff);
                    141:        } else {
                    142:                bp->av_forw = mfsp->mfs_buflist;
                    143:                mfsp->mfs_buflist = bp;
                    144:                wakeup((caddr_t)vp);
                    145:        }
                    146:        return (0);
                    147: }
                    148: 
                    149: /*
                    150:  * Memory file system I/O.
                    151:  *
1.1.1.2 ! root      152:  * Trivial since buffer has already been mapping into KVA space.
1.1       root      153:  */
                    154: mfs_doio(bp, base)
                    155:        register struct buf *bp;
                    156:        caddr_t base;
                    157: {
                    158:        base += (bp->b_blkno << DEV_BSHIFT);
                    159:        if (bp->b_flags & B_READ)
                    160:                bp->b_error = copyin(base, bp->b_un.b_addr, bp->b_bcount);
                    161:        else
                    162:                bp->b_error = copyout(bp->b_un.b_addr, base, bp->b_bcount);
                    163:        if (bp->b_error)
                    164:                bp->b_flags |= B_ERROR;
                    165:        biodone(bp);
                    166: }
                    167: 
                    168: /*
                    169:  * This is a noop, simply returning what one has been given.
                    170:  */
                    171: mfs_bmap(vp, bn, vpp, bnp)
                    172:        struct vnode *vp;
                    173:        daddr_t bn;
                    174:        struct vnode **vpp;
                    175:        daddr_t *bnp;
                    176: {
                    177: 
                    178:        if (vpp != NULL)
                    179:                *vpp = vp;
                    180:        if (bnp != NULL)
                    181:                *bnp = bn;
                    182:        return (0);
                    183: }
                    184: 
                    185: /*
                    186:  * Memory filesystem close routine
                    187:  */
                    188: /* ARGSUSED */
                    189: mfs_close(vp, flag, cred, p)
                    190:        register struct vnode *vp;
                    191:        int flag;
                    192:        struct ucred *cred;
                    193:        struct proc *p;
                    194: {
                    195:        register struct mfsnode *mfsp = VTOMFS(vp);
                    196:        register struct buf *bp;
                    197: 
                    198:        /*
                    199:         * Finish any pending I/O requests.
                    200:         */
                    201:        while (bp = mfsp->mfs_buflist) {
                    202:                mfsp->mfs_buflist = bp->av_forw;
                    203:                mfs_doio(bp, mfsp->mfs_baseoff);
                    204:                wakeup((caddr_t)bp);
                    205:        }
                    206:        /*
                    207:         * On last close of a memory filesystem
                    208:         * we must invalidate any in core blocks, so that
                    209:         * we can, free up its vnode.
                    210:         */
                    211:        vflushbuf(vp, 0);
                    212:        if (vinvalbuf(vp, 1))
                    213:                return (0);
                    214:        /*
                    215:         * There should be no way to have any more uses of this
                    216:         * vnode, so if we find any other uses, it is a panic.
                    217:         */
                    218:        if (vp->v_usecount > 1)
                    219:                printf("mfs_close: ref count %d > 1\n", vp->v_usecount);
                    220:        if (vp->v_usecount > 1 || mfsp->mfs_buflist)
                    221:                panic("mfs_close");
                    222:        /*
                    223:         * Send a request to the filesystem server to exit.
                    224:         */
                    225:        mfsp->mfs_buflist = (struct buf *)(-1);
                    226:        wakeup((caddr_t)vp);
                    227:        return (0);
                    228: }
                    229: 
                    230: /*
                    231:  * Memory filesystem inactive routine
                    232:  */
                    233: /* ARGSUSED */
                    234: mfs_inactive(vp, p)
                    235:        struct vnode *vp;
                    236:        struct proc *p;
                    237: {
                    238: 
                    239:        if (VTOMFS(vp)->mfs_buflist != (struct buf *)(-1))
                    240:                panic("mfs_inactive: not inactive");
                    241:        return (0);
                    242: }
                    243: 
                    244: /*
                    245:  * Print out the contents of an mfsnode.
                    246:  */
                    247: mfs_print(vp)
                    248:        struct vnode *vp;
                    249: {
                    250:        register struct mfsnode *mfsp = VTOMFS(vp);
                    251: 
                    252:        printf("tag VT_MFS, pid %d, base %d, size %d\n", mfsp->mfs_pid,
                    253:                mfsp->mfs_baseoff, mfsp->mfs_size);
                    254: }
                    255: 
                    256: /*
                    257:  * Block device bad operation
                    258:  */
                    259: mfs_badop()
                    260: {
                    261: 
                    262:        panic("mfs_badop called\n");
                    263:        /* NOTREACHED */
                    264: }
                    265: 
                    266: /*
                    267:  * Memory based filesystem initialization.
                    268:  */
                    269: mfs_init()
                    270: {
                    271: 
                    272: }

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