Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 1 | /* |
| 2 | * undo_io.c --- This is the undo io manager that copies the old data that |
| 3 | * copies the old data being overwritten into a tdb database |
| 4 | * |
| 5 | * Copyright IBM Corporation, 2007 |
| 6 | * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> |
| 7 | * |
| 8 | * %Begin-Header% |
Theodore Ts'o | 543547a | 2010-05-17 21:31:56 -0400 | [diff] [blame] | 9 | * This file may be redistributed under the terms of the GNU Library |
| 10 | * General Public License, version 2. |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 11 | * %End-Header% |
| 12 | */ |
| 13 | |
| 14 | #define _LARGEFILE_SOURCE |
| 15 | #define _LARGEFILE64_SOURCE |
| 16 | |
Theodore Ts'o | d1154eb | 2011-09-18 17:34:37 -0400 | [diff] [blame] | 17 | #include "config.h" |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 18 | #include <stdio.h> |
| 19 | #include <string.h> |
| 20 | #if HAVE_UNISTD_H |
| 21 | #include <unistd.h> |
| 22 | #endif |
| 23 | #if HAVE_ERRNO_H |
| 24 | #include <errno.h> |
| 25 | #endif |
| 26 | #include <fcntl.h> |
| 27 | #include <time.h> |
| 28 | #ifdef __linux__ |
| 29 | #include <sys/utsname.h> |
| 30 | #endif |
| 31 | #if HAVE_SYS_STAT_H |
| 32 | #include <sys/stat.h> |
| 33 | #endif |
| 34 | #if HAVE_SYS_TYPES_H |
| 35 | #include <sys/types.h> |
| 36 | #endif |
| 37 | #if HAVE_SYS_RESOURCE_H |
| 38 | #include <sys/resource.h> |
| 39 | #endif |
| 40 | |
| 41 | #include "tdb.h" |
| 42 | |
| 43 | #include "ext2_fs.h" |
| 44 | #include "ext2fs.h" |
| 45 | |
Theodore Ts'o | 8895f43 | 2008-06-07 11:53:56 -0400 | [diff] [blame] | 46 | #ifdef __GNUC__ |
| 47 | #define ATTR(x) __attribute__(x) |
| 48 | #else |
| 49 | #define ATTR(x) |
| 50 | #endif |
| 51 | |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 52 | /* |
| 53 | * For checking structure magic numbers... |
| 54 | */ |
| 55 | |
| 56 | #define EXT2_CHECK_MAGIC(struct, code) \ |
| 57 | if ((struct)->magic != (code)) return (code) |
| 58 | |
| 59 | struct undo_private_data { |
| 60 | int magic; |
| 61 | TDB_CONTEXT *tdb; |
| 62 | char *tdb_file; |
| 63 | |
| 64 | /* The backing io channel */ |
| 65 | io_channel real; |
| 66 | |
| 67 | int tdb_data_size; |
| 68 | int tdb_written; |
| 69 | |
| 70 | /* to support offset in unix I/O manager */ |
| 71 | ext2_loff_t offset; |
| 72 | }; |
| 73 | |
| 74 | static errcode_t undo_open(const char *name, int flags, io_channel *channel); |
| 75 | static errcode_t undo_close(io_channel channel); |
| 76 | static errcode_t undo_set_blksize(io_channel channel, int blksize); |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 77 | static errcode_t undo_read_blk64(io_channel channel, unsigned long long block, |
| 78 | int count, void *data); |
| 79 | static errcode_t undo_write_blk64(io_channel channel, unsigned long long block, |
| 80 | int count, const void *data); |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 81 | static errcode_t undo_read_blk(io_channel channel, unsigned long block, |
| 82 | int count, void *data); |
| 83 | static errcode_t undo_write_blk(io_channel channel, unsigned long block, |
| 84 | int count, const void *data); |
| 85 | static errcode_t undo_flush(io_channel channel); |
| 86 | static errcode_t undo_write_byte(io_channel channel, unsigned long offset, |
| 87 | int size, const void *data); |
| 88 | static errcode_t undo_set_option(io_channel channel, const char *option, |
| 89 | const char *arg); |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 90 | static errcode_t undo_get_stats(io_channel channel, io_stats *stats); |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 91 | |
| 92 | static struct struct_io_manager struct_undo_manager = { |
| 93 | EXT2_ET_MAGIC_IO_MANAGER, |
| 94 | "Undo I/O Manager", |
| 95 | undo_open, |
| 96 | undo_close, |
| 97 | undo_set_blksize, |
| 98 | undo_read_blk, |
| 99 | undo_write_blk, |
| 100 | undo_flush, |
| 101 | undo_write_byte, |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 102 | undo_set_option, |
| 103 | undo_get_stats, |
| 104 | undo_read_blk64, |
| 105 | undo_write_blk64, |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 106 | }; |
| 107 | |
| 108 | io_manager undo_io_manager = &struct_undo_manager; |
| 109 | static io_manager undo_io_backing_manager ; |
| 110 | static char *tdb_file; |
| 111 | static int actual_size; |
| 112 | |
Theodore Ts'o | 8895f43 | 2008-06-07 11:53:56 -0400 | [diff] [blame] | 113 | static unsigned char mtime_key[] = "filesystem MTIME"; |
| 114 | static unsigned char blksize_key[] = "filesystem BLKSIZE"; |
| 115 | static unsigned char uuid_key[] = "filesystem UUID"; |
| 116 | |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 117 | errcode_t set_undo_io_backing_manager(io_manager manager) |
| 118 | { |
| 119 | /* |
| 120 | * We may want to do some validation later |
| 121 | */ |
| 122 | undo_io_backing_manager = manager; |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | errcode_t set_undo_io_backup_file(char *file_name) |
| 127 | { |
| 128 | tdb_file = strdup(file_name); |
| 129 | |
| 130 | if (tdb_file == NULL) { |
| 131 | return EXT2_ET_NO_MEMORY; |
| 132 | } |
| 133 | |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | static errcode_t write_file_system_identity(io_channel undo_channel, |
| 138 | TDB_CONTEXT *tdb) |
| 139 | { |
| 140 | errcode_t retval; |
| 141 | struct ext2_super_block super; |
| 142 | TDB_DATA tdb_key, tdb_data; |
| 143 | struct undo_private_data *data; |
| 144 | io_channel channel; |
| 145 | int block_size ; |
| 146 | |
| 147 | data = (struct undo_private_data *) undo_channel->private_data; |
| 148 | channel = data->real; |
| 149 | block_size = channel->block_size; |
| 150 | |
| 151 | io_channel_set_blksize(channel, SUPERBLOCK_OFFSET); |
Valerie Aurora Henson | 24a117a | 2009-09-07 21:14:24 -0400 | [diff] [blame] | 152 | retval = io_channel_read_blk64(channel, 1, -SUPERBLOCK_SIZE, &super); |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 153 | if (retval) |
| 154 | goto err_out; |
| 155 | |
| 156 | /* Write to tdb file in the file system byte order */ |
Theodore Ts'o | 8895f43 | 2008-06-07 11:53:56 -0400 | [diff] [blame] | 157 | tdb_key.dptr = mtime_key; |
| 158 | tdb_key.dsize = sizeof(mtime_key); |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 159 | tdb_data.dptr = (unsigned char *) &(super.s_mtime); |
| 160 | tdb_data.dsize = sizeof(super.s_mtime); |
| 161 | |
| 162 | retval = tdb_store(tdb, tdb_key, tdb_data, TDB_INSERT); |
| 163 | if (retval == -1) { |
| 164 | retval = EXT2_ET_TDB_SUCCESS + tdb_error(tdb); |
| 165 | goto err_out; |
| 166 | } |
| 167 | |
Theodore Ts'o | 8895f43 | 2008-06-07 11:53:56 -0400 | [diff] [blame] | 168 | tdb_key.dptr = uuid_key; |
| 169 | tdb_key.dsize = sizeof(uuid_key); |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 170 | tdb_data.dptr = (unsigned char *)&(super.s_uuid); |
| 171 | tdb_data.dsize = sizeof(super.s_uuid); |
| 172 | |
| 173 | retval = tdb_store(tdb, tdb_key, tdb_data, TDB_INSERT); |
| 174 | if (retval == -1) { |
| 175 | retval = EXT2_ET_TDB_SUCCESS + tdb_error(tdb); |
| 176 | } |
| 177 | |
| 178 | err_out: |
| 179 | io_channel_set_blksize(channel, block_size); |
| 180 | return retval; |
| 181 | } |
| 182 | |
| 183 | static errcode_t write_block_size(TDB_CONTEXT *tdb, int block_size) |
| 184 | { |
| 185 | errcode_t retval; |
| 186 | TDB_DATA tdb_key, tdb_data; |
| 187 | |
Theodore Ts'o | 8895f43 | 2008-06-07 11:53:56 -0400 | [diff] [blame] | 188 | tdb_key.dptr = blksize_key; |
| 189 | tdb_key.dsize = sizeof(blksize_key); |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 190 | tdb_data.dptr = (unsigned char *)&(block_size); |
| 191 | tdb_data.dsize = sizeof(block_size); |
| 192 | |
| 193 | retval = tdb_store(tdb, tdb_key, tdb_data, TDB_INSERT); |
| 194 | if (retval == -1) { |
| 195 | retval = EXT2_ET_TDB_SUCCESS + tdb_error(tdb); |
| 196 | } |
| 197 | |
| 198 | return retval; |
| 199 | } |
| 200 | |
| 201 | static errcode_t undo_write_tdb(io_channel channel, |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 202 | unsigned long long block, int count) |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 203 | |
| 204 | { |
Theodore Ts'o | 8895f43 | 2008-06-07 11:53:56 -0400 | [diff] [blame] | 205 | int size, sz; |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 206 | unsigned long long block_num, backing_blk_num; |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 207 | errcode_t retval = 0; |
| 208 | ext2_loff_t offset; |
| 209 | struct undo_private_data *data; |
| 210 | TDB_DATA tdb_key, tdb_data; |
Theodore Ts'o | 8895f43 | 2008-06-07 11:53:56 -0400 | [diff] [blame] | 211 | unsigned char *read_ptr; |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 212 | unsigned long long end_block; |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 213 | |
| 214 | data = (struct undo_private_data *) channel->private_data; |
| 215 | |
| 216 | if (data->tdb == NULL) { |
| 217 | /* |
| 218 | * Transaction database not initialized |
| 219 | */ |
| 220 | return 0; |
| 221 | } |
| 222 | |
| 223 | if (count == 1) |
| 224 | size = channel->block_size; |
| 225 | else { |
| 226 | if (count < 0) |
| 227 | size = -count; |
| 228 | else |
| 229 | size = count * channel->block_size; |
| 230 | } |
| 231 | /* |
| 232 | * Data is stored in tdb database as blocks of tdb_data_size size |
| 233 | * This helps in efficient lookup further. |
| 234 | * |
| 235 | * We divide the disk to blocks of tdb_data_size. |
| 236 | */ |
| 237 | offset = (block * channel->block_size) + data->offset ; |
| 238 | block_num = offset / data->tdb_data_size; |
| 239 | end_block = (offset + size) / data->tdb_data_size; |
| 240 | |
| 241 | tdb_transaction_start(data->tdb); |
| 242 | while (block_num <= end_block ) { |
| 243 | |
| 244 | tdb_key.dptr = (unsigned char *)&block_num; |
| 245 | tdb_key.dsize = sizeof(block_num); |
| 246 | /* |
| 247 | * Check if we have the record already |
| 248 | */ |
| 249 | if (tdb_exists(data->tdb, tdb_key)) { |
| 250 | /* Try the next block */ |
| 251 | block_num++; |
| 252 | continue; |
| 253 | } |
| 254 | /* |
| 255 | * Read one block using the backing I/O manager |
| 256 | * The backing I/O manager block size may be |
| 257 | * different from the tdb_data_size. |
| 258 | * Also we need to recalcuate the block number with respect |
| 259 | * to the backing I/O manager. |
| 260 | */ |
| 261 | offset = block_num * data->tdb_data_size; |
| 262 | backing_blk_num = (offset - data->offset) / channel->block_size; |
| 263 | |
| 264 | count = data->tdb_data_size + |
| 265 | ((offset - data->offset) % channel->block_size); |
| 266 | retval = ext2fs_get_mem(count, &read_ptr); |
| 267 | if (retval) { |
| 268 | tdb_transaction_cancel(data->tdb); |
| 269 | return retval; |
| 270 | } |
| 271 | |
| 272 | memset(read_ptr, 0, count); |
| 273 | actual_size = 0; |
| 274 | if ((count % channel->block_size) == 0) |
| 275 | sz = count / channel->block_size; |
| 276 | else |
| 277 | sz = -count; |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 278 | retval = io_channel_read_blk64(data->real, backing_blk_num, |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 279 | sz, read_ptr); |
| 280 | if (retval) { |
| 281 | if (retval != EXT2_ET_SHORT_READ) { |
| 282 | free(read_ptr); |
| 283 | tdb_transaction_cancel(data->tdb); |
| 284 | return retval; |
| 285 | } |
| 286 | /* |
| 287 | * short read so update the record size |
| 288 | * accordingly |
| 289 | */ |
| 290 | tdb_data.dsize = actual_size; |
| 291 | } else { |
| 292 | tdb_data.dsize = data->tdb_data_size; |
| 293 | } |
| 294 | tdb_data.dptr = read_ptr + |
| 295 | ((offset - data->offset) % channel->block_size); |
| 296 | #ifdef DEBUG |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 297 | printf("Printing with key %lld data %x and size %d\n", |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 298 | block_num, |
| 299 | tdb_data.dptr, |
| 300 | tdb_data.dsize); |
| 301 | #endif |
| 302 | if (!data->tdb_written) { |
| 303 | data->tdb_written = 1; |
| 304 | /* Write the blocksize to tdb file */ |
| 305 | retval = write_block_size(data->tdb, |
| 306 | data->tdb_data_size); |
| 307 | if (retval) { |
| 308 | tdb_transaction_cancel(data->tdb); |
| 309 | retval = EXT2_ET_TDB_ERR_IO; |
| 310 | free(read_ptr); |
| 311 | return retval; |
| 312 | } |
| 313 | } |
| 314 | retval = tdb_store(data->tdb, tdb_key, tdb_data, TDB_INSERT); |
| 315 | if (retval == -1) { |
| 316 | /* |
| 317 | * TDB_ERR_EXISTS cannot happen because we |
| 318 | * have already verified it doesn't exist |
| 319 | */ |
| 320 | tdb_transaction_cancel(data->tdb); |
| 321 | retval = EXT2_ET_TDB_ERR_IO; |
| 322 | free(read_ptr); |
| 323 | return retval; |
| 324 | } |
| 325 | free(read_ptr); |
| 326 | /* Next block */ |
| 327 | block_num++; |
| 328 | } |
| 329 | tdb_transaction_commit(data->tdb); |
| 330 | |
| 331 | return retval; |
| 332 | } |
| 333 | |
Theodore Ts'o | 8895f43 | 2008-06-07 11:53:56 -0400 | [diff] [blame] | 334 | static errcode_t undo_io_read_error(io_channel channel ATTR((unused)), |
| 335 | unsigned long block ATTR((unused)), |
| 336 | int count ATTR((unused)), |
| 337 | void *data ATTR((unused)), |
| 338 | size_t size ATTR((unused)), |
| 339 | int actual, |
| 340 | errcode_t error ATTR((unused))) |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 341 | { |
| 342 | actual_size = actual; |
| 343 | return error; |
| 344 | } |
| 345 | |
| 346 | static void undo_err_handler_init(io_channel channel) |
| 347 | { |
| 348 | channel->read_error = undo_io_read_error; |
| 349 | } |
| 350 | |
| 351 | static errcode_t undo_open(const char *name, int flags, io_channel *channel) |
| 352 | { |
| 353 | io_channel io = NULL; |
| 354 | struct undo_private_data *data = NULL; |
| 355 | errcode_t retval; |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 356 | |
| 357 | if (name == 0) |
| 358 | return EXT2_ET_BAD_DEVICE_NAME; |
| 359 | retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io); |
| 360 | if (retval) |
Eric Sandeen | 624e8eb | 2011-09-16 15:49:28 -0500 | [diff] [blame] | 361 | goto cleanup; |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 362 | memset(io, 0, sizeof(struct struct_io_channel)); |
| 363 | io->magic = EXT2_ET_MAGIC_IO_CHANNEL; |
| 364 | retval = ext2fs_get_mem(sizeof(struct undo_private_data), &data); |
| 365 | if (retval) |
| 366 | goto cleanup; |
| 367 | |
| 368 | io->manager = undo_io_manager; |
| 369 | retval = ext2fs_get_mem(strlen(name)+1, &io->name); |
| 370 | if (retval) |
| 371 | goto cleanup; |
| 372 | |
| 373 | strcpy(io->name, name); |
| 374 | io->private_data = data; |
| 375 | io->block_size = 1024; |
| 376 | io->read_error = 0; |
| 377 | io->write_error = 0; |
| 378 | io->refcount = 1; |
| 379 | |
| 380 | memset(data, 0, sizeof(struct undo_private_data)); |
| 381 | data->magic = EXT2_ET_MAGIC_UNIX_IO_CHANNEL; |
| 382 | |
| 383 | if (undo_io_backing_manager) { |
| 384 | retval = undo_io_backing_manager->open(name, flags, |
| 385 | &data->real); |
| 386 | if (retval) |
| 387 | goto cleanup; |
| 388 | } else { |
| 389 | data->real = 0; |
| 390 | } |
| 391 | |
| 392 | /* setup the tdb file */ |
| 393 | data->tdb = tdb_open(tdb_file, 0, TDB_CLEAR_IF_FIRST, |
| 394 | O_RDWR | O_CREAT | O_TRUNC | O_EXCL, 0600); |
| 395 | if (!data->tdb) { |
| 396 | retval = errno; |
| 397 | goto cleanup; |
| 398 | } |
| 399 | |
| 400 | /* |
| 401 | * setup err handler for read so that we know |
| 402 | * when the backing manager fails do short read |
| 403 | */ |
Eric Sandeen | 665563b | 2011-09-16 15:49:21 -0500 | [diff] [blame] | 404 | if (data->real) |
| 405 | undo_err_handler_init(data->real); |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 406 | |
| 407 | *channel = io; |
| 408 | return 0; |
| 409 | |
| 410 | cleanup: |
Eric Sandeen | 624e8eb | 2011-09-16 15:49:28 -0500 | [diff] [blame] | 411 | if (data && data->real) |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 412 | io_channel_close(data->real); |
| 413 | if (data) |
| 414 | ext2fs_free_mem(&data); |
| 415 | if (io) |
| 416 | ext2fs_free_mem(&io); |
| 417 | return retval; |
| 418 | } |
| 419 | |
| 420 | static errcode_t undo_close(io_channel channel) |
| 421 | { |
| 422 | struct undo_private_data *data; |
| 423 | errcode_t retval = 0; |
| 424 | |
| 425 | EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); |
| 426 | data = (struct undo_private_data *) channel->private_data; |
| 427 | EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL); |
| 428 | |
| 429 | if (--channel->refcount > 0) |
| 430 | return 0; |
| 431 | /* Before closing write the file system identity */ |
| 432 | retval = write_file_system_identity(channel, data->tdb); |
| 433 | if (retval) |
| 434 | return retval; |
| 435 | if (data->real) |
| 436 | retval = io_channel_close(data->real); |
| 437 | if (data->tdb) |
| 438 | tdb_close(data->tdb); |
| 439 | ext2fs_free_mem(&channel->private_data); |
| 440 | if (channel->name) |
| 441 | ext2fs_free_mem(&channel->name); |
| 442 | ext2fs_free_mem(&channel); |
| 443 | |
| 444 | return retval; |
| 445 | } |
| 446 | |
| 447 | static errcode_t undo_set_blksize(io_channel channel, int blksize) |
| 448 | { |
| 449 | struct undo_private_data *data; |
Theodore Ts'o | 8895f43 | 2008-06-07 11:53:56 -0400 | [diff] [blame] | 450 | errcode_t retval = 0; |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 451 | |
| 452 | EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); |
| 453 | data = (struct undo_private_data *) channel->private_data; |
| 454 | EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL); |
| 455 | |
| 456 | if (data->real) |
| 457 | retval = io_channel_set_blksize(data->real, blksize); |
| 458 | /* |
| 459 | * Set the block size used for tdb |
| 460 | */ |
| 461 | if (!data->tdb_data_size) { |
| 462 | data->tdb_data_size = blksize; |
| 463 | } |
| 464 | channel->block_size = blksize; |
| 465 | return retval; |
| 466 | } |
| 467 | |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 468 | static errcode_t undo_read_blk64(io_channel channel, unsigned long long block, |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 469 | int count, void *buf) |
| 470 | { |
Theodore Ts'o | 8895f43 | 2008-06-07 11:53:56 -0400 | [diff] [blame] | 471 | errcode_t retval = 0; |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 472 | struct undo_private_data *data; |
| 473 | |
| 474 | EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); |
| 475 | data = (struct undo_private_data *) channel->private_data; |
| 476 | EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL); |
| 477 | |
| 478 | if (data->real) |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 479 | retval = io_channel_read_blk64(data->real, block, count, buf); |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 480 | |
| 481 | return retval; |
| 482 | } |
| 483 | |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 484 | static errcode_t undo_read_blk(io_channel channel, unsigned long block, |
| 485 | int count, void *buf) |
| 486 | { |
| 487 | return undo_read_blk64(channel, block, count, buf); |
| 488 | } |
| 489 | |
| 490 | static errcode_t undo_write_blk64(io_channel channel, unsigned long long block, |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 491 | int count, const void *buf) |
| 492 | { |
| 493 | struct undo_private_data *data; |
| 494 | errcode_t retval = 0; |
| 495 | |
| 496 | EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); |
| 497 | data = (struct undo_private_data *) channel->private_data; |
| 498 | EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL); |
| 499 | /* |
| 500 | * First write the existing content into database |
| 501 | */ |
| 502 | retval = undo_write_tdb(channel, block, count); |
| 503 | if (retval) |
| 504 | return retval; |
| 505 | if (data->real) |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 506 | retval = io_channel_write_blk64(data->real, block, count, buf); |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 507 | |
| 508 | return retval; |
| 509 | } |
| 510 | |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 511 | static errcode_t undo_write_blk(io_channel channel, unsigned long block, |
| 512 | int count, const void *buf) |
| 513 | { |
| 514 | return undo_write_blk64(channel, block, count, buf); |
| 515 | } |
| 516 | |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 517 | static errcode_t undo_write_byte(io_channel channel, unsigned long offset, |
| 518 | int size, const void *buf) |
| 519 | { |
| 520 | struct undo_private_data *data; |
| 521 | errcode_t retval = 0; |
Aneesh Kumar K.V | 72a168b | 2007-08-13 15:56:21 +0530 | [diff] [blame] | 522 | ext2_loff_t location; |
| 523 | unsigned long blk_num, count;; |
| 524 | |
| 525 | EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); |
| 526 | data = (struct undo_private_data *) channel->private_data; |
| 527 | EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL); |
| 528 | |
| 529 | location = offset + data->offset; |
| 530 | blk_num = location/channel->block_size; |
| 531 | /* |
| 532 | * the size specified may spread across multiple blocks |
| 533 | * also make sure we account for the fact that block start |
| 534 | * offset for tdb is different from the backing I/O manager |
| 535 | * due to possible different block size |
| 536 | */ |
| 537 | count = (size + (location % channel->block_size) + |
| 538 | channel->block_size -1)/channel->block_size; |
| 539 | retval = undo_write_tdb(channel, blk_num, count); |
| 540 | if (retval) |
| 541 | return retval; |
| 542 | if (data->real && data->real->manager->write_byte) |
| 543 | retval = io_channel_write_byte(data->real, offset, size, buf); |
| 544 | |
| 545 | return retval; |
| 546 | } |
| 547 | |
| 548 | /* |
| 549 | * Flush data buffers to disk. |
| 550 | */ |
| 551 | static errcode_t undo_flush(io_channel channel) |
| 552 | { |
| 553 | errcode_t retval = 0; |
| 554 | struct undo_private_data *data; |
| 555 | |
| 556 | EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); |
| 557 | data = (struct undo_private_data *) channel->private_data; |
| 558 | EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL); |
| 559 | |
| 560 | if (data->real) |
| 561 | retval = io_channel_flush(data->real); |
| 562 | |
| 563 | return retval; |
| 564 | } |
| 565 | |
| 566 | static errcode_t undo_set_option(io_channel channel, const char *option, |
| 567 | const char *arg) |
| 568 | { |
| 569 | errcode_t retval = 0; |
| 570 | struct undo_private_data *data; |
| 571 | unsigned long tmp; |
| 572 | char *end; |
| 573 | |
| 574 | EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); |
| 575 | data = (struct undo_private_data *) channel->private_data; |
| 576 | EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL); |
| 577 | |
| 578 | if (!strcmp(option, "tdb_data_size")) { |
| 579 | if (!arg) |
| 580 | return EXT2_ET_INVALID_ARGUMENT; |
| 581 | |
| 582 | tmp = strtoul(arg, &end, 0); |
| 583 | if (*end) |
| 584 | return EXT2_ET_INVALID_ARGUMENT; |
| 585 | if (!data->tdb_data_size || !data->tdb_written) { |
| 586 | data->tdb_data_size = tmp; |
| 587 | } |
| 588 | return 0; |
| 589 | } |
| 590 | /* |
| 591 | * Need to support offset option to work with |
| 592 | * Unix I/O manager |
| 593 | */ |
| 594 | if (data->real && data->real->manager->set_option) { |
| 595 | retval = data->real->manager->set_option(data->real, |
| 596 | option, arg); |
| 597 | } |
| 598 | if (!retval && !strcmp(option, "offset")) { |
| 599 | if (!arg) |
| 600 | return EXT2_ET_INVALID_ARGUMENT; |
| 601 | |
| 602 | tmp = strtoul(arg, &end, 0); |
| 603 | if (*end) |
| 604 | return EXT2_ET_INVALID_ARGUMENT; |
| 605 | data->offset = tmp; |
| 606 | } |
| 607 | return retval; |
| 608 | } |
Theodore Ts'o | 1adc384 | 2009-07-12 00:53:57 -0400 | [diff] [blame] | 609 | |
| 610 | static errcode_t undo_get_stats(io_channel channel, io_stats *stats) |
| 611 | { |
| 612 | errcode_t retval = 0; |
| 613 | struct undo_private_data *data; |
| 614 | |
| 615 | EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL); |
| 616 | data = (struct undo_private_data *) channel->private_data; |
| 617 | EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL); |
| 618 | |
| 619 | if (data->real) |
| 620 | retval = (data->real->manager->get_stats)(data->real, stats); |
| 621 | |
| 622 | return retval; |
| 623 | } |