1 | /*
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2 | Unix SMB/CIFS implementation.
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3 |
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4 | generic byte range locking code - tdb backend
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5 |
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6 | Copyright (C) Andrew Tridgell 1992-2006
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7 | Copyright (C) Jeremy Allison 1992-2000
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8 |
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9 | This program is free software; you can redistribute it and/or modify
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10 | it under the terms of the GNU General Public License as published by
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11 | the Free Software Foundation; either version 3 of the License, or
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12 | (at your option) any later version.
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13 |
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14 | This program is distributed in the hope that it will be useful,
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15 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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17 | GNU General Public License for more details.
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18 |
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19 | You should have received a copy of the GNU General Public License
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20 | along with this program. If not, see <http://www.gnu.org/licenses/>.
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21 | */
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22 |
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23 | /* This module implements a tdb based byte range locking service,
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24 | replacing the fcntl() based byte range locking previously
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25 | used. This allows us to provide the same semantics as NT */
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26 |
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27 | #include "includes.h"
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28 | #include "system/filesys.h"
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29 | #include "../tdb/include/tdb.h"
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30 | #include "messaging/messaging.h"
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31 | #include "tdb_wrap.h"
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32 | #include "lib/messaging/irpc.h"
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33 | #include "libcli/libcli.h"
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34 | #include "cluster/cluster.h"
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35 | #include "ntvfs/common/brlock.h"
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36 | #include "ntvfs/ntvfs.h"
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37 | #include "param/param.h"
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38 |
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39 | /*
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40 | in this module a "DATA_BLOB *file_key" is a blob that uniquely identifies
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41 | a file. For a local posix filesystem this will usually be a combination
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42 | of the device and inode numbers of the file, but it can be anything
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43 | that uniquely idetifies a file for locking purposes, as long
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44 | as it is applied consistently.
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45 | */
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46 |
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47 | /* this struct is typicaly attached to tcon */
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48 | struct brl_context {
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49 | struct tdb_wrap *w;
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50 | struct server_id server;
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51 | struct messaging_context *messaging_ctx;
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52 | };
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53 |
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54 | /*
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55 | the lock context contains the elements that define whether one
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56 | lock is the same as another lock
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57 | */
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58 | struct lock_context {
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59 | struct server_id server;
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60 | uint32_t smbpid;
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61 | struct brl_context *ctx;
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62 | };
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63 |
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64 | /* The data in brlock records is an unsorted linear array of these
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65 | records. It is unnecessary to store the count as tdb provides the
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66 | size of the record */
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67 | struct lock_struct {
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68 | struct lock_context context;
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69 | struct ntvfs_handle *ntvfs;
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70 | uint64_t start;
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71 | uint64_t size;
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72 | enum brl_type lock_type;
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73 | void *notify_ptr;
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74 | };
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75 |
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76 | /* this struct is attached to on oprn file handle */
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77 | struct brl_handle {
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78 | DATA_BLOB key;
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79 | struct ntvfs_handle *ntvfs;
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80 | struct lock_struct last_lock;
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81 | };
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82 |
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83 | /*
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84 | Open up the brlock.tdb database. Close it down using
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85 | talloc_free(). We need the messaging_ctx to allow for
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86 | pending lock notifications.
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87 | */
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88 | static struct brl_context *brl_tdb_init(TALLOC_CTX *mem_ctx, struct server_id server,
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89 | struct loadparm_context *lp_ctx,
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90 | struct messaging_context *messaging_ctx)
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91 | {
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92 | struct brl_context *brl;
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93 |
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94 | brl = talloc(mem_ctx, struct brl_context);
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95 | if (brl == NULL) {
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96 | return NULL;
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97 | }
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98 |
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99 | brl->w = cluster_tdb_tmp_open(brl, lp_ctx, "brlock.tdb", TDB_DEFAULT);
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100 | if (brl->w == NULL) {
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101 | talloc_free(brl);
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102 | return NULL;
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103 | }
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104 |
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105 | brl->server = server;
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106 | brl->messaging_ctx = messaging_ctx;
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107 |
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108 | return brl;
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109 | }
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110 |
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111 | static struct brl_handle *brl_tdb_create_handle(TALLOC_CTX *mem_ctx, struct ntvfs_handle *ntvfs,
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112 | DATA_BLOB *file_key)
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113 | {
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114 | struct brl_handle *brlh;
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115 |
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116 | brlh = talloc(mem_ctx, struct brl_handle);
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117 | if (brlh == NULL) {
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118 | return NULL;
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119 | }
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120 |
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121 | brlh->key = *file_key;
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122 | brlh->ntvfs = ntvfs;
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123 | ZERO_STRUCT(brlh->last_lock);
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124 |
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125 | return brlh;
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126 | }
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127 |
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128 | /*
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129 | see if two locking contexts are equal
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130 | */
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131 | static bool brl_tdb_same_context(struct lock_context *ctx1, struct lock_context *ctx2)
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132 | {
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133 | return (cluster_id_equal(&ctx1->server, &ctx2->server) &&
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134 | ctx1->smbpid == ctx2->smbpid &&
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135 | ctx1->ctx == ctx2->ctx);
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136 | }
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137 |
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138 | /*
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139 | see if lck1 and lck2 overlap
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140 |
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141 | lck1 is the existing lock. lck2 is the new lock we are
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142 | looking at adding
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143 | */
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144 | static bool brl_tdb_overlap(struct lock_struct *lck1,
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145 | struct lock_struct *lck2)
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146 | {
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147 | /* this extra check is not redundent - it copes with locks
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148 | that go beyond the end of 64 bit file space */
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149 | if (lck1->size != 0 &&
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150 | lck1->start == lck2->start &&
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151 | lck1->size == lck2->size) {
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152 | return true;
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153 | }
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154 |
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155 | if (lck1->start >= (lck2->start+lck2->size) ||
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156 | lck2->start >= (lck1->start+lck1->size)) {
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157 | return false;
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158 | }
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159 |
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160 | /* we have a conflict. Now check to see if lck1 really still
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161 | * exists, which involves checking if the process still
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162 | * exists. We leave this test to last as its the most
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163 | * expensive test, especially when we are clustered */
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164 | /* TODO: need to do this via a server_id_exists() call, which
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165 | * hasn't been written yet. When clustered this will need to
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166 | * call into ctdb */
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167 |
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168 | return true;
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169 | }
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170 |
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171 | /*
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172 | See if lock2 can be added when lock1 is in place.
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173 | */
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174 | static bool brl_tdb_conflict(struct lock_struct *lck1,
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175 | struct lock_struct *lck2)
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176 | {
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177 | /* pending locks don't conflict with anything */
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178 | if (lck1->lock_type >= PENDING_READ_LOCK ||
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179 | lck2->lock_type >= PENDING_READ_LOCK) {
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180 | return false;
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181 | }
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182 |
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183 | if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK) {
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184 | return false;
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185 | }
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186 |
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187 | if (brl_tdb_same_context(&lck1->context, &lck2->context) &&
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188 | lck2->lock_type == READ_LOCK && lck1->ntvfs == lck2->ntvfs) {
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189 | return false;
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190 | }
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191 |
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192 | return brl_tdb_overlap(lck1, lck2);
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193 | }
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194 |
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195 |
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196 | /*
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197 | Check to see if this lock conflicts, but ignore our own locks on the
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198 | same fnum only.
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199 | */
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200 | static bool brl_tdb_conflict_other(struct lock_struct *lck1, struct lock_struct *lck2)
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201 | {
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202 | /* pending locks don't conflict with anything */
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203 | if (lck1->lock_type >= PENDING_READ_LOCK ||
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204 | lck2->lock_type >= PENDING_READ_LOCK) {
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205 | return false;
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206 | }
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207 |
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208 | if (lck1->lock_type == READ_LOCK && lck2->lock_type == READ_LOCK)
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209 | return false;
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210 |
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211 | /*
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212 | * note that incoming write calls conflict with existing READ
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213 | * locks even if the context is the same. JRA. See LOCKTEST7
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214 | * in smbtorture.
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215 | */
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216 | if (brl_tdb_same_context(&lck1->context, &lck2->context) &&
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217 | lck1->ntvfs == lck2->ntvfs &&
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218 | (lck2->lock_type == READ_LOCK || lck1->lock_type == WRITE_LOCK)) {
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219 | return false;
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220 | }
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221 |
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222 | return brl_tdb_overlap(lck1, lck2);
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223 | }
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224 |
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225 |
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226 | /*
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227 | amazingly enough, w2k3 "remembers" whether the last lock failure
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228 | is the same as this one and changes its error code. I wonder if any
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229 | app depends on this?
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230 | */
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231 | static NTSTATUS brl_tdb_lock_failed(struct brl_handle *brlh, struct lock_struct *lock)
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232 | {
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233 | /*
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234 | * this function is only called for non pending lock!
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235 | */
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236 |
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237 | /* in SMB2 mode always return NT_STATUS_LOCK_NOT_GRANTED! */
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238 | if (lock->ntvfs->ctx->protocol == PROTOCOL_SMB2) {
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239 | return NT_STATUS_LOCK_NOT_GRANTED;
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240 | }
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241 |
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242 | /*
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243 | * if the notify_ptr is non NULL,
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244 | * it means that we're at the end of a pending lock
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245 | * and the real lock is requested after the timout went by
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246 | * In this case we need to remember the last_lock and always
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247 | * give FILE_LOCK_CONFLICT
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248 | */
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249 | if (lock->notify_ptr) {
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250 | brlh->last_lock = *lock;
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251 | return NT_STATUS_FILE_LOCK_CONFLICT;
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252 | }
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253 |
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254 | /*
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255 | * amazing the little things you learn with a test
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256 | * suite. Locks beyond this offset (as a 64 bit
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257 | * number!) always generate the conflict error code,
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258 | * unless the top bit is set
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259 | */
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260 | if (lock->start >= 0xEF000000 && (lock->start >> 63) == 0) {
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261 | brlh->last_lock = *lock;
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262 | return NT_STATUS_FILE_LOCK_CONFLICT;
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263 | }
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264 |
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265 | /*
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266 | * if the current lock matches the last failed lock on the file handle
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267 | * and starts at the same offset, then FILE_LOCK_CONFLICT should be returned
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268 | */
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269 | if (cluster_id_equal(&lock->context.server, &brlh->last_lock.context.server) &&
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270 | lock->context.ctx == brlh->last_lock.context.ctx &&
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271 | lock->ntvfs == brlh->last_lock.ntvfs &&
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272 | lock->start == brlh->last_lock.start) {
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273 | return NT_STATUS_FILE_LOCK_CONFLICT;
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274 | }
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275 |
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276 | brlh->last_lock = *lock;
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277 | return NT_STATUS_LOCK_NOT_GRANTED;
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278 | }
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279 |
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280 | /*
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281 | Lock a range of bytes. The lock_type can be a PENDING_*_LOCK, in
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282 | which case a real lock is first tried, and if that fails then a
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283 | pending lock is created. When the pending lock is triggered (by
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284 | someone else closing an overlapping lock range) a messaging
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285 | notification is sent, identified by the notify_ptr
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286 | */
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287 | static NTSTATUS brl_tdb_lock(struct brl_context *brl,
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288 | struct brl_handle *brlh,
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289 | uint32_t smbpid,
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290 | uint64_t start, uint64_t size,
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291 | enum brl_type lock_type,
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292 | void *notify_ptr)
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293 | {
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294 | TDB_DATA kbuf, dbuf;
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295 | int count=0, i;
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296 | struct lock_struct lock, *locks=NULL;
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297 | NTSTATUS status;
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298 |
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299 | kbuf.dptr = brlh->key.data;
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300 | kbuf.dsize = brlh->key.length;
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301 |
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302 | if (tdb_chainlock(brl->w->tdb, kbuf) != 0) {
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303 | return NT_STATUS_INTERNAL_DB_CORRUPTION;
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304 | }
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305 |
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306 | /* if this is a pending lock, then with the chainlock held we
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307 | try to get the real lock. If we succeed then we don't need
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308 | to make it pending. This prevents a possible race condition
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309 | where the pending lock gets created after the lock that is
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310 | preventing the real lock gets removed */
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311 | if (lock_type >= PENDING_READ_LOCK) {
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312 | enum brl_type rw = (lock_type==PENDING_READ_LOCK? READ_LOCK : WRITE_LOCK);
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313 |
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314 | /* here we need to force that the last_lock isn't overwritten */
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315 | lock = brlh->last_lock;
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316 | status = brl_tdb_lock(brl, brlh, smbpid, start, size, rw, NULL);
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317 | brlh->last_lock = lock;
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318 |
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319 | if (NT_STATUS_IS_OK(status)) {
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320 | tdb_chainunlock(brl->w->tdb, kbuf);
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321 | return NT_STATUS_OK;
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322 | }
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323 | }
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324 |
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325 | dbuf = tdb_fetch(brl->w->tdb, kbuf);
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326 |
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327 | lock.context.smbpid = smbpid;
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328 | lock.context.server = brl->server;
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329 | lock.context.ctx = brl;
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330 | lock.ntvfs = brlh->ntvfs;
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331 | lock.context.ctx = brl;
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332 | lock.start = start;
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333 | lock.size = size;
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334 | lock.lock_type = lock_type;
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335 | lock.notify_ptr = notify_ptr;
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336 |
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337 | if (dbuf.dptr) {
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338 | /* there are existing locks - make sure they don't conflict */
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339 | locks = (struct lock_struct *)dbuf.dptr;
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340 | count = dbuf.dsize / sizeof(*locks);
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341 | for (i=0; i<count; i++) {
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342 | if (brl_tdb_conflict(&locks[i], &lock)) {
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343 | status = brl_tdb_lock_failed(brlh, &lock);
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344 | goto fail;
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345 | }
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346 | }
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347 | }
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348 |
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349 | /* no conflicts - add it to the list of locks */
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350 | locks = realloc_p(locks, struct lock_struct, count+1);
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351 | if (!locks) {
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352 | status = NT_STATUS_NO_MEMORY;
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353 | goto fail;
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354 | } else {
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355 | dbuf.dptr = (uint8_t *)locks;
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356 | }
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357 | locks[count] = lock;
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358 | dbuf.dsize += sizeof(lock);
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359 |
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360 | if (tdb_store(brl->w->tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
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361 | status = NT_STATUS_INTERNAL_DB_CORRUPTION;
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362 | goto fail;
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363 | }
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364 |
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365 | free(dbuf.dptr);
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366 | tdb_chainunlock(brl->w->tdb, kbuf);
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367 |
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368 | /* the caller needs to know if the real lock was granted. If
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369 | we have reached here then it must be a pending lock that
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370 | was granted, so tell them the lock failed */
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371 | if (lock_type >= PENDING_READ_LOCK) {
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372 | return NT_STATUS_LOCK_NOT_GRANTED;
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373 | }
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374 |
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375 | return NT_STATUS_OK;
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376 |
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377 | fail:
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378 |
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379 | free(dbuf.dptr);
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380 | tdb_chainunlock(brl->w->tdb, kbuf);
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381 | return status;
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382 | }
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383 |
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384 |
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385 | /*
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386 | we are removing a lock that might be holding up a pending lock. Scan for pending
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387 | locks that cover this range and if we find any then notify the server that it should
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388 | retry the lock
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389 | */
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390 | static void brl_tdb_notify_unlock(struct brl_context *brl,
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391 | struct lock_struct *locks, int count,
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392 | struct lock_struct *removed_lock)
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393 | {
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394 | int i, last_notice;
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395 |
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396 | /* the last_notice logic is to prevent stampeding on a lock
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397 | range. It prevents us sending hundreds of notifies on the
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398 | same range of bytes. It doesn't prevent all possible
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399 | stampedes, but it does prevent the most common problem */
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400 | last_notice = -1;
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401 |
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402 | for (i=0;i<count;i++) {
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403 | if (locks[i].lock_type >= PENDING_READ_LOCK &&
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404 | brl_tdb_overlap(&locks[i], removed_lock)) {
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405 | if (last_notice != -1 && brl_tdb_overlap(&locks[i], &locks[last_notice])) {
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406 | continue;
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407 | }
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408 | if (locks[i].lock_type == PENDING_WRITE_LOCK) {
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409 | last_notice = i;
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410 | }
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411 | messaging_send_ptr(brl->messaging_ctx, locks[i].context.server,
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412 | MSG_BRL_RETRY, locks[i].notify_ptr);
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413 | }
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414 | }
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415 | }
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416 |
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417 |
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418 | /*
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419 | send notifications for all pending locks - the file is being closed by this
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420 | user
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421 | */
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422 | static void brl_tdb_notify_all(struct brl_context *brl,
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423 | struct lock_struct *locks, int count)
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424 | {
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425 | int i;
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426 | for (i=0;i<count;i++) {
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427 | if (locks->lock_type >= PENDING_READ_LOCK) {
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428 | brl_tdb_notify_unlock(brl, locks, count, &locks[i]);
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429 | }
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430 | }
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431 | }
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432 |
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433 |
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434 |
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435 | /*
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436 | Unlock a range of bytes.
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437 | */
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438 | static NTSTATUS brl_tdb_unlock(struct brl_context *brl,
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439 | struct brl_handle *brlh,
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440 | uint32_t smbpid,
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441 | uint64_t start, uint64_t size)
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442 | {
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443 | TDB_DATA kbuf, dbuf;
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444 | int count, i;
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445 | struct lock_struct *locks, *lock;
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446 | struct lock_context context;
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447 | NTSTATUS status;
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448 |
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449 | kbuf.dptr = brlh->key.data;
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450 | kbuf.dsize = brlh->key.length;
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451 |
|
---|
452 | if (tdb_chainlock(brl->w->tdb, kbuf) != 0) {
|
---|
453 | return NT_STATUS_INTERNAL_DB_CORRUPTION;
|
---|
454 | }
|
---|
455 |
|
---|
456 | dbuf = tdb_fetch(brl->w->tdb, kbuf);
|
---|
457 | if (!dbuf.dptr) {
|
---|
458 | tdb_chainunlock(brl->w->tdb, kbuf);
|
---|
459 | return NT_STATUS_RANGE_NOT_LOCKED;
|
---|
460 | }
|
---|
461 |
|
---|
462 | context.smbpid = smbpid;
|
---|
463 | context.server = brl->server;
|
---|
464 | context.ctx = brl;
|
---|
465 |
|
---|
466 | /* there are existing locks - find a match */
|
---|
467 | locks = (struct lock_struct *)dbuf.dptr;
|
---|
468 | count = dbuf.dsize / sizeof(*locks);
|
---|
469 |
|
---|
470 | for (i=0; i<count; i++) {
|
---|
471 | lock = &locks[i];
|
---|
472 | if (brl_tdb_same_context(&lock->context, &context) &&
|
---|
473 | lock->ntvfs == brlh->ntvfs &&
|
---|
474 | lock->start == start &&
|
---|
475 | lock->size == size &&
|
---|
476 | lock->lock_type == WRITE_LOCK) {
|
---|
477 | break;
|
---|
478 | }
|
---|
479 | }
|
---|
480 | if (i < count) goto found;
|
---|
481 |
|
---|
482 | for (i=0; i<count; i++) {
|
---|
483 | lock = &locks[i];
|
---|
484 | if (brl_tdb_same_context(&lock->context, &context) &&
|
---|
485 | lock->ntvfs == brlh->ntvfs &&
|
---|
486 | lock->start == start &&
|
---|
487 | lock->size == size &&
|
---|
488 | lock->lock_type < PENDING_READ_LOCK) {
|
---|
489 | break;
|
---|
490 | }
|
---|
491 | }
|
---|
492 |
|
---|
493 | found:
|
---|
494 | if (i < count) {
|
---|
495 | /* found it - delete it */
|
---|
496 | if (count == 1) {
|
---|
497 | if (tdb_delete(brl->w->tdb, kbuf) != 0) {
|
---|
498 | status = NT_STATUS_INTERNAL_DB_CORRUPTION;
|
---|
499 | goto fail;
|
---|
500 | }
|
---|
501 | } else {
|
---|
502 | struct lock_struct removed_lock = *lock;
|
---|
503 | if (i < count-1) {
|
---|
504 | memmove(&locks[i], &locks[i+1],
|
---|
505 | sizeof(*locks)*((count-1) - i));
|
---|
506 | }
|
---|
507 | count--;
|
---|
508 |
|
---|
509 | /* send notifications for any relevant pending locks */
|
---|
510 | brl_tdb_notify_unlock(brl, locks, count, &removed_lock);
|
---|
511 |
|
---|
512 | dbuf.dsize = count * sizeof(*locks);
|
---|
513 |
|
---|
514 | if (tdb_store(brl->w->tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
|
---|
515 | status = NT_STATUS_INTERNAL_DB_CORRUPTION;
|
---|
516 | goto fail;
|
---|
517 | }
|
---|
518 | }
|
---|
519 |
|
---|
520 | free(dbuf.dptr);
|
---|
521 | tdb_chainunlock(brl->w->tdb, kbuf);
|
---|
522 | return NT_STATUS_OK;
|
---|
523 | }
|
---|
524 |
|
---|
525 | /* we didn't find it */
|
---|
526 | status = NT_STATUS_RANGE_NOT_LOCKED;
|
---|
527 |
|
---|
528 | fail:
|
---|
529 | free(dbuf.dptr);
|
---|
530 | tdb_chainunlock(brl->w->tdb, kbuf);
|
---|
531 | return status;
|
---|
532 | }
|
---|
533 |
|
---|
534 |
|
---|
535 | /*
|
---|
536 | remove a pending lock. This is called when the caller has either
|
---|
537 | given up trying to establish a lock or when they have succeeded in
|
---|
538 | getting it. In either case they no longer need to be notified.
|
---|
539 | */
|
---|
540 | static NTSTATUS brl_tdb_remove_pending(struct brl_context *brl,
|
---|
541 | struct brl_handle *brlh,
|
---|
542 | void *notify_ptr)
|
---|
543 | {
|
---|
544 | TDB_DATA kbuf, dbuf;
|
---|
545 | int count, i;
|
---|
546 | struct lock_struct *locks;
|
---|
547 | NTSTATUS status;
|
---|
548 |
|
---|
549 | kbuf.dptr = brlh->key.data;
|
---|
550 | kbuf.dsize = brlh->key.length;
|
---|
551 |
|
---|
552 | if (tdb_chainlock(brl->w->tdb, kbuf) != 0) {
|
---|
553 | return NT_STATUS_INTERNAL_DB_CORRUPTION;
|
---|
554 | }
|
---|
555 |
|
---|
556 | dbuf = tdb_fetch(brl->w->tdb, kbuf);
|
---|
557 | if (!dbuf.dptr) {
|
---|
558 | tdb_chainunlock(brl->w->tdb, kbuf);
|
---|
559 | return NT_STATUS_RANGE_NOT_LOCKED;
|
---|
560 | }
|
---|
561 |
|
---|
562 | /* there are existing locks - find a match */
|
---|
563 | locks = (struct lock_struct *)dbuf.dptr;
|
---|
564 | count = dbuf.dsize / sizeof(*locks);
|
---|
565 |
|
---|
566 | for (i=0; i<count; i++) {
|
---|
567 | struct lock_struct *lock = &locks[i];
|
---|
568 |
|
---|
569 | if (lock->lock_type >= PENDING_READ_LOCK &&
|
---|
570 | lock->notify_ptr == notify_ptr &&
|
---|
571 | cluster_id_equal(&lock->context.server, &brl->server)) {
|
---|
572 | /* found it - delete it */
|
---|
573 | if (count == 1) {
|
---|
574 | if (tdb_delete(brl->w->tdb, kbuf) != 0) {
|
---|
575 | status = NT_STATUS_INTERNAL_DB_CORRUPTION;
|
---|
576 | goto fail;
|
---|
577 | }
|
---|
578 | } else {
|
---|
579 | if (i < count-1) {
|
---|
580 | memmove(&locks[i], &locks[i+1],
|
---|
581 | sizeof(*locks)*((count-1) - i));
|
---|
582 | }
|
---|
583 | count--;
|
---|
584 | dbuf.dsize = count * sizeof(*locks);
|
---|
585 | if (tdb_store(brl->w->tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
|
---|
586 | status = NT_STATUS_INTERNAL_DB_CORRUPTION;
|
---|
587 | goto fail;
|
---|
588 | }
|
---|
589 | }
|
---|
590 |
|
---|
591 | free(dbuf.dptr);
|
---|
592 | tdb_chainunlock(brl->w->tdb, kbuf);
|
---|
593 | return NT_STATUS_OK;
|
---|
594 | }
|
---|
595 | }
|
---|
596 |
|
---|
597 | /* we didn't find it */
|
---|
598 | status = NT_STATUS_RANGE_NOT_LOCKED;
|
---|
599 |
|
---|
600 | fail:
|
---|
601 | free(dbuf.dptr);
|
---|
602 | tdb_chainunlock(brl->w->tdb, kbuf);
|
---|
603 | return status;
|
---|
604 | }
|
---|
605 |
|
---|
606 |
|
---|
607 | /*
|
---|
608 | Test if we are allowed to perform IO on a region of an open file
|
---|
609 | */
|
---|
610 | static NTSTATUS brl_tdb_locktest(struct brl_context *brl,
|
---|
611 | struct brl_handle *brlh,
|
---|
612 | uint32_t smbpid,
|
---|
613 | uint64_t start, uint64_t size,
|
---|
614 | enum brl_type lock_type)
|
---|
615 | {
|
---|
616 | TDB_DATA kbuf, dbuf;
|
---|
617 | int count, i;
|
---|
618 | struct lock_struct lock, *locks;
|
---|
619 |
|
---|
620 | kbuf.dptr = brlh->key.data;
|
---|
621 | kbuf.dsize = brlh->key.length;
|
---|
622 |
|
---|
623 | dbuf = tdb_fetch(brl->w->tdb, kbuf);
|
---|
624 | if (dbuf.dptr == NULL) {
|
---|
625 | return NT_STATUS_OK;
|
---|
626 | }
|
---|
627 |
|
---|
628 | lock.context.smbpid = smbpid;
|
---|
629 | lock.context.server = brl->server;
|
---|
630 | lock.context.ctx = brl;
|
---|
631 | lock.ntvfs = brlh->ntvfs;
|
---|
632 | lock.start = start;
|
---|
633 | lock.size = size;
|
---|
634 | lock.lock_type = lock_type;
|
---|
635 |
|
---|
636 | /* there are existing locks - make sure they don't conflict */
|
---|
637 | locks = (struct lock_struct *)dbuf.dptr;
|
---|
638 | count = dbuf.dsize / sizeof(*locks);
|
---|
639 |
|
---|
640 | for (i=0; i<count; i++) {
|
---|
641 | if (brl_tdb_conflict_other(&locks[i], &lock)) {
|
---|
642 | free(dbuf.dptr);
|
---|
643 | return NT_STATUS_FILE_LOCK_CONFLICT;
|
---|
644 | }
|
---|
645 | }
|
---|
646 |
|
---|
647 | free(dbuf.dptr);
|
---|
648 | return NT_STATUS_OK;
|
---|
649 | }
|
---|
650 |
|
---|
651 |
|
---|
652 | /*
|
---|
653 | Remove any locks associated with a open file.
|
---|
654 | */
|
---|
655 | static NTSTATUS brl_tdb_close(struct brl_context *brl,
|
---|
656 | struct brl_handle *brlh)
|
---|
657 | {
|
---|
658 | TDB_DATA kbuf, dbuf;
|
---|
659 | int count, i, dcount=0;
|
---|
660 | struct lock_struct *locks;
|
---|
661 | NTSTATUS status;
|
---|
662 |
|
---|
663 | kbuf.dptr = brlh->key.data;
|
---|
664 | kbuf.dsize = brlh->key.length;
|
---|
665 |
|
---|
666 | if (tdb_chainlock(brl->w->tdb, kbuf) != 0) {
|
---|
667 | return NT_STATUS_INTERNAL_DB_CORRUPTION;
|
---|
668 | }
|
---|
669 |
|
---|
670 | dbuf = tdb_fetch(brl->w->tdb, kbuf);
|
---|
671 | if (!dbuf.dptr) {
|
---|
672 | tdb_chainunlock(brl->w->tdb, kbuf);
|
---|
673 | return NT_STATUS_OK;
|
---|
674 | }
|
---|
675 |
|
---|
676 | /* there are existing locks - remove any for this fnum */
|
---|
677 | locks = (struct lock_struct *)dbuf.dptr;
|
---|
678 | count = dbuf.dsize / sizeof(*locks);
|
---|
679 |
|
---|
680 | for (i=0; i<count; i++) {
|
---|
681 | struct lock_struct *lock = &locks[i];
|
---|
682 |
|
---|
683 | if (lock->context.ctx == brl &&
|
---|
684 | cluster_id_equal(&lock->context.server, &brl->server) &&
|
---|
685 | lock->ntvfs == brlh->ntvfs) {
|
---|
686 | /* found it - delete it */
|
---|
687 | if (count > 1 && i < count-1) {
|
---|
688 | memmove(&locks[i], &locks[i+1],
|
---|
689 | sizeof(*locks)*((count-1) - i));
|
---|
690 | }
|
---|
691 | count--;
|
---|
692 | i--;
|
---|
693 | dcount++;
|
---|
694 | }
|
---|
695 | }
|
---|
696 |
|
---|
697 | status = NT_STATUS_OK;
|
---|
698 |
|
---|
699 | if (count == 0) {
|
---|
700 | if (tdb_delete(brl->w->tdb, kbuf) != 0) {
|
---|
701 | status = NT_STATUS_INTERNAL_DB_CORRUPTION;
|
---|
702 | }
|
---|
703 | } else if (dcount != 0) {
|
---|
704 | /* tell all pending lock holders for this file that
|
---|
705 | they have a chance now. This is a bit indiscriminant,
|
---|
706 | but works OK */
|
---|
707 | brl_tdb_notify_all(brl, locks, count);
|
---|
708 |
|
---|
709 | dbuf.dsize = count * sizeof(*locks);
|
---|
710 |
|
---|
711 | if (tdb_store(brl->w->tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
|
---|
712 | status = NT_STATUS_INTERNAL_DB_CORRUPTION;
|
---|
713 | }
|
---|
714 | }
|
---|
715 |
|
---|
716 | free(dbuf.dptr);
|
---|
717 | tdb_chainunlock(brl->w->tdb, kbuf);
|
---|
718 |
|
---|
719 | return status;
|
---|
720 | }
|
---|
721 |
|
---|
722 |
|
---|
723 | static const struct brlock_ops brlock_tdb_ops = {
|
---|
724 | .brl_init = brl_tdb_init,
|
---|
725 | .brl_create_handle = brl_tdb_create_handle,
|
---|
726 | .brl_lock = brl_tdb_lock,
|
---|
727 | .brl_unlock = brl_tdb_unlock,
|
---|
728 | .brl_remove_pending = brl_tdb_remove_pending,
|
---|
729 | .brl_locktest = brl_tdb_locktest,
|
---|
730 | .brl_close = brl_tdb_close
|
---|
731 | };
|
---|
732 |
|
---|
733 |
|
---|
734 | void brl_tdb_init_ops(void)
|
---|
735 | {
|
---|
736 | brl_set_ops(&brlock_tdb_ops);
|
---|
737 | }
|
---|