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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License, Version 1.0 only
      6  * (the "License").  You may not use this file except in compliance
      7  * with the License.
      8  *
      9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
     10  * or http://www.opensolaris.org/os/licensing.
     11  * See the License for the specific language governing permissions
     12  * and limitations under the License.
     13  *
     14  * When distributing Covered Code, include this CDDL HEADER in each
     15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     16  * If applicable, add the following below this CDDL HEADER, with the
     17  * fields enclosed by brackets "[]" replaced with your own identifying
     18  * information: Portions Copyright [yyyy] [name of copyright owner]
     19  *
     20  * CDDL HEADER END
     21  */
     22 /*
     23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     28 
     29 /*
     30  * This file contains interface definitions and wrappers for file
     31  * system snapshot support.  File systems may depend on this module
     32  * for symbol resolution while the implementation may remain unloaded
     33  * until needed.
     34  */
     35 #include <sys/types.h>
     36 #include <sys/debug.h>
     37 #include <sys/t_lock.h>
     38 #include <sys/param.h>
     39 #include <sys/mman.h>
     40 #include <sys/systm.h>
     41 #include <sys/errno.h>
     42 #include <sys/kmem.h>
     43 #include <sys/cmn_err.h>
     44 #include <sys/vnode.h>
     45 #include <sys/debug.h>
     46 #include <sys/proc.h>
     47 #include <sys/user.h>
     48 #include <sys/conf.h>
     49 #include <sys/modctl.h>
     50 #include <sys/fssnap_if.h>
     51 
     52 struct fssnap_operations snapops = {
     53 	NULL,	/* fssnap_create */
     54 	NULL,	/* fssnap_set_candidate */
     55 	NULL,	/* fssnap_is_candidate */
     56 	NULL,	/* fssnap_create_done */
     57 	NULL,	/* fssnap_delete */
     58 	NULL	/* fssnap_strategy */
     59 };
     60 
     61 void *
     62 fssnap_create(chunknumber_t nchunks, uint_t chunksz, u_offset_t maxsize,
     63     struct vnode *fsvp, int backfilecount, struct vnode **bfvpp, char *backpath,
     64     u_offset_t max_backfile_size)
     65 {
     66 	void *snapid = NULL;
     67 
     68 	if (snapops.fssnap_create)
     69 		snapid = (snapops.fssnap_create)(nchunks, chunksz, maxsize,
     70 		    fsvp, backfilecount, bfvpp, backpath, max_backfile_size);
     71 
     72 	return (snapid);
     73 }
     74 
     75 void
     76 fssnap_set_candidate(void *snapshot_id, chunknumber_t chunknumber)
     77 {
     78 	if (snapops.fssnap_set_candidate)
     79 		(snapops.fssnap_set_candidate)(snapshot_id, chunknumber);
     80 }
     81 
     82 int
     83 fssnap_is_candidate(void *snapshot_id, u_offset_t off)
     84 {
     85 	int rc = 0;
     86 
     87 	if (snapops.fssnap_is_candidate)
     88 		rc = (snapops.fssnap_is_candidate)(snapshot_id, off);
     89 
     90 	return (rc);
     91 }
     92 
     93 int
     94 fssnap_create_done(void *snapshot_id)
     95 {
     96 	int snapslot = -1;
     97 
     98 	if (snapops.fssnap_create_done)
     99 		snapslot = (snapops.fssnap_create_done)(snapshot_id);
    100 
    101 	return (snapslot);
    102 }
    103 
    104 int
    105 fssnap_delete(void *snapshot_id)
    106 {
    107 	int snapslot = -1;
    108 
    109 	if (snapops.fssnap_delete)
    110 		snapslot = (snapops.fssnap_delete)(snapshot_id);
    111 
    112 	return (snapslot);
    113 }
    114 
    115 void
    116 fssnap_strategy(void *snapshot_id, struct buf *bp)
    117 {
    118 	if (snapops.fssnap_strategy)
    119 		(snapops.fssnap_strategy)(snapshot_id, bp);
    120 }
    121 
    122 
    123 #include <sys/modctl.h>
    124 
    125 extern struct mod_ops mod_miscops;
    126 
    127 static struct modlmisc modlmisc = {
    128 	&mod_miscops, "File System Snapshot Interface",
    129 };
    130 
    131 static struct modlinkage modlinkage = {
    132 	MODREV_1, (void *)&modlmisc, NULL
    133 };
    134 
    135 int
    136 _init(void)
    137 {
    138 	return (mod_install(&modlinkage));
    139 }
    140 
    141 /*
    142  * Unloading is MT-safe because our client drivers use
    143  * the _depends_on[] mechanism - we won't go while they're
    144  * still around.
    145  */
    146 int
    147 _fini(void)
    148 {
    149 	return (mod_remove(&modlinkage));
    150 }
    151 
    152 int
    153 _info(struct modinfo *modinfop)
    154 {
    155 	return (mod_info(&modlinkage, modinfop));
    156 }
    157