usr/src/uts/common/io/fssnap_if.c

   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 }