Tao Ma | 67cf5b0 | 2012-12-10 14:04:46 -0500 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 2012 Taobao. |
| 3 | * Written by Tao Ma <boyu.mt@taobao.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of version 2.1 of the GNU Lesser General Public License |
| 7 | * as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | */ |
| 14 | #include "ext4_jbd2.h" |
| 15 | #include "ext4.h" |
| 16 | #include "xattr.h" |
| 17 | |
| 18 | #define EXT4_XATTR_SYSTEM_DATA "data" |
| 19 | #define EXT4_MIN_INLINE_DATA_SIZE ((sizeof(__le32) * EXT4_N_BLOCKS)) |
| 20 | |
| 21 | int ext4_get_inline_size(struct inode *inode) |
| 22 | { |
| 23 | if (EXT4_I(inode)->i_inline_off) |
| 24 | return EXT4_I(inode)->i_inline_size; |
| 25 | |
| 26 | return 0; |
| 27 | } |
| 28 | |
| 29 | static int get_max_inline_xattr_value_size(struct inode *inode, |
| 30 | struct ext4_iloc *iloc) |
| 31 | { |
| 32 | struct ext4_xattr_ibody_header *header; |
| 33 | struct ext4_xattr_entry *entry; |
| 34 | struct ext4_inode *raw_inode; |
| 35 | int free, min_offs; |
| 36 | |
| 37 | min_offs = EXT4_SB(inode->i_sb)->s_inode_size - |
| 38 | EXT4_GOOD_OLD_INODE_SIZE - |
| 39 | EXT4_I(inode)->i_extra_isize - |
| 40 | sizeof(struct ext4_xattr_ibody_header); |
| 41 | |
| 42 | /* |
| 43 | * We need to subtract another sizeof(__u32) since an in-inode xattr |
| 44 | * needs an empty 4 bytes to indicate the gap between the xattr entry |
| 45 | * and the name/value pair. |
| 46 | */ |
| 47 | if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) |
| 48 | return EXT4_XATTR_SIZE(min_offs - |
| 49 | EXT4_XATTR_LEN(strlen(EXT4_XATTR_SYSTEM_DATA)) - |
| 50 | EXT4_XATTR_ROUND - sizeof(__u32)); |
| 51 | |
| 52 | raw_inode = ext4_raw_inode(iloc); |
| 53 | header = IHDR(inode, raw_inode); |
| 54 | entry = IFIRST(header); |
| 55 | |
| 56 | /* Compute min_offs. */ |
| 57 | for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { |
| 58 | if (!entry->e_value_block && entry->e_value_size) { |
| 59 | size_t offs = le16_to_cpu(entry->e_value_offs); |
| 60 | if (offs < min_offs) |
| 61 | min_offs = offs; |
| 62 | } |
| 63 | } |
| 64 | free = min_offs - |
| 65 | ((void *)entry - (void *)IFIRST(header)) - sizeof(__u32); |
| 66 | |
| 67 | if (EXT4_I(inode)->i_inline_off) { |
| 68 | entry = (struct ext4_xattr_entry *) |
| 69 | ((void *)raw_inode + EXT4_I(inode)->i_inline_off); |
| 70 | |
| 71 | free += le32_to_cpu(entry->e_value_size); |
| 72 | goto out; |
| 73 | } |
| 74 | |
| 75 | free -= EXT4_XATTR_LEN(strlen(EXT4_XATTR_SYSTEM_DATA)); |
| 76 | |
| 77 | if (free > EXT4_XATTR_ROUND) |
| 78 | free = EXT4_XATTR_SIZE(free - EXT4_XATTR_ROUND); |
| 79 | else |
| 80 | free = 0; |
| 81 | |
| 82 | out: |
| 83 | return free; |
| 84 | } |
| 85 | |
| 86 | /* |
| 87 | * Get the maximum size we now can store in an inode. |
| 88 | * If we can't find the space for a xattr entry, don't use the space |
| 89 | * of the extents since we have no space to indicate the inline data. |
| 90 | */ |
| 91 | int ext4_get_max_inline_size(struct inode *inode) |
| 92 | { |
| 93 | int error, max_inline_size; |
| 94 | struct ext4_iloc iloc; |
| 95 | |
| 96 | if (EXT4_I(inode)->i_extra_isize == 0) |
| 97 | return 0; |
| 98 | |
| 99 | error = ext4_get_inode_loc(inode, &iloc); |
| 100 | if (error) { |
| 101 | ext4_error_inode(inode, __func__, __LINE__, 0, |
| 102 | "can't get inode location %lu", |
| 103 | inode->i_ino); |
| 104 | return 0; |
| 105 | } |
| 106 | |
| 107 | down_read(&EXT4_I(inode)->xattr_sem); |
| 108 | max_inline_size = get_max_inline_xattr_value_size(inode, &iloc); |
| 109 | up_read(&EXT4_I(inode)->xattr_sem); |
| 110 | |
| 111 | brelse(iloc.bh); |
| 112 | |
| 113 | if (!max_inline_size) |
| 114 | return 0; |
| 115 | |
| 116 | return max_inline_size + EXT4_MIN_INLINE_DATA_SIZE; |
| 117 | } |
| 118 | |
| 119 | int ext4_has_inline_data(struct inode *inode) |
| 120 | { |
| 121 | return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) && |
| 122 | EXT4_I(inode)->i_inline_off; |
| 123 | } |
| 124 | |
| 125 | /* |
| 126 | * this function does not take xattr_sem, which is OK because it is |
| 127 | * currently only used in a code path coming form ext4_iget, before |
| 128 | * the new inode has been unlocked |
| 129 | */ |
| 130 | int ext4_find_inline_data_nolock(struct inode *inode) |
| 131 | { |
| 132 | struct ext4_xattr_ibody_find is = { |
| 133 | .s = { .not_found = -ENODATA, }, |
| 134 | }; |
| 135 | struct ext4_xattr_info i = { |
| 136 | .name_index = EXT4_XATTR_INDEX_SYSTEM, |
| 137 | .name = EXT4_XATTR_SYSTEM_DATA, |
| 138 | }; |
| 139 | int error; |
| 140 | |
| 141 | if (EXT4_I(inode)->i_extra_isize == 0) |
| 142 | return 0; |
| 143 | |
| 144 | error = ext4_get_inode_loc(inode, &is.iloc); |
| 145 | if (error) |
| 146 | return error; |
| 147 | |
| 148 | error = ext4_xattr_ibody_find(inode, &i, &is); |
| 149 | if (error) |
| 150 | goto out; |
| 151 | |
| 152 | if (!is.s.not_found) { |
| 153 | EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here - |
| 154 | (void *)ext4_raw_inode(&is.iloc)); |
| 155 | EXT4_I(inode)->i_inline_size = EXT4_MIN_INLINE_DATA_SIZE + |
| 156 | le32_to_cpu(is.s.here->e_value_size); |
| 157 | ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); |
| 158 | } |
| 159 | out: |
| 160 | brelse(is.iloc.bh); |
| 161 | return error; |
| 162 | } |
| 163 | |
| 164 | static int ext4_read_inline_data(struct inode *inode, void *buffer, |
| 165 | unsigned int len, |
| 166 | struct ext4_iloc *iloc) |
| 167 | { |
| 168 | struct ext4_xattr_entry *entry; |
| 169 | struct ext4_xattr_ibody_header *header; |
| 170 | int cp_len = 0; |
| 171 | struct ext4_inode *raw_inode; |
| 172 | |
| 173 | if (!len) |
| 174 | return 0; |
| 175 | |
| 176 | BUG_ON(len > EXT4_I(inode)->i_inline_size); |
| 177 | |
| 178 | cp_len = len < EXT4_MIN_INLINE_DATA_SIZE ? |
| 179 | len : EXT4_MIN_INLINE_DATA_SIZE; |
| 180 | |
| 181 | raw_inode = ext4_raw_inode(iloc); |
| 182 | memcpy(buffer, (void *)(raw_inode->i_block), cp_len); |
| 183 | |
| 184 | len -= cp_len; |
| 185 | buffer += cp_len; |
| 186 | |
| 187 | if (!len) |
| 188 | goto out; |
| 189 | |
| 190 | header = IHDR(inode, raw_inode); |
| 191 | entry = (struct ext4_xattr_entry *)((void *)raw_inode + |
| 192 | EXT4_I(inode)->i_inline_off); |
| 193 | len = min_t(unsigned int, len, |
| 194 | (unsigned int)le32_to_cpu(entry->e_value_size)); |
| 195 | |
| 196 | memcpy(buffer, |
| 197 | (void *)IFIRST(header) + le16_to_cpu(entry->e_value_offs), len); |
| 198 | cp_len += len; |
| 199 | |
| 200 | out: |
| 201 | return cp_len; |
| 202 | } |
| 203 | |
| 204 | /* |
| 205 | * write the buffer to the inline inode. |
| 206 | * If 'create' is set, we don't need to do the extra copy in the xattr |
| 207 | * value since it is already handled by ext4_xattr_ibody_set. That saves |
| 208 | * us one memcpy. |
| 209 | */ |
| 210 | void ext4_write_inline_data(struct inode *inode, struct ext4_iloc *iloc, |
| 211 | void *buffer, loff_t pos, unsigned int len) |
| 212 | { |
| 213 | struct ext4_xattr_entry *entry; |
| 214 | struct ext4_xattr_ibody_header *header; |
| 215 | struct ext4_inode *raw_inode; |
| 216 | int cp_len = 0; |
| 217 | |
| 218 | BUG_ON(!EXT4_I(inode)->i_inline_off); |
| 219 | BUG_ON(pos + len > EXT4_I(inode)->i_inline_size); |
| 220 | |
| 221 | raw_inode = ext4_raw_inode(iloc); |
| 222 | buffer += pos; |
| 223 | |
| 224 | if (pos < EXT4_MIN_INLINE_DATA_SIZE) { |
| 225 | cp_len = pos + len > EXT4_MIN_INLINE_DATA_SIZE ? |
| 226 | EXT4_MIN_INLINE_DATA_SIZE - pos : len; |
| 227 | memcpy((void *)raw_inode->i_block + pos, buffer, cp_len); |
| 228 | |
| 229 | len -= cp_len; |
| 230 | buffer += cp_len; |
| 231 | pos += cp_len; |
| 232 | } |
| 233 | |
| 234 | if (!len) |
| 235 | return; |
| 236 | |
| 237 | pos -= EXT4_MIN_INLINE_DATA_SIZE; |
| 238 | header = IHDR(inode, raw_inode); |
| 239 | entry = (struct ext4_xattr_entry *)((void *)raw_inode + |
| 240 | EXT4_I(inode)->i_inline_off); |
| 241 | |
| 242 | memcpy((void *)IFIRST(header) + le16_to_cpu(entry->e_value_offs) + pos, |
| 243 | buffer, len); |
| 244 | } |
| 245 | |
| 246 | static int ext4_create_inline_data(handle_t *handle, |
| 247 | struct inode *inode, unsigned len) |
| 248 | { |
| 249 | int error; |
| 250 | void *value = NULL; |
| 251 | struct ext4_xattr_ibody_find is = { |
| 252 | .s = { .not_found = -ENODATA, }, |
| 253 | }; |
| 254 | struct ext4_xattr_info i = { |
| 255 | .name_index = EXT4_XATTR_INDEX_SYSTEM, |
| 256 | .name = EXT4_XATTR_SYSTEM_DATA, |
| 257 | }; |
| 258 | |
| 259 | error = ext4_get_inode_loc(inode, &is.iloc); |
| 260 | if (error) |
| 261 | return error; |
| 262 | |
| 263 | error = ext4_journal_get_write_access(handle, is.iloc.bh); |
| 264 | if (error) |
| 265 | goto out; |
| 266 | |
| 267 | if (len > EXT4_MIN_INLINE_DATA_SIZE) { |
| 268 | value = (void *)empty_zero_page; |
| 269 | len -= EXT4_MIN_INLINE_DATA_SIZE; |
| 270 | } else { |
| 271 | value = ""; |
| 272 | len = 0; |
| 273 | } |
| 274 | |
| 275 | /* Insert the the xttr entry. */ |
| 276 | i.value = value; |
| 277 | i.value_len = len; |
| 278 | |
| 279 | error = ext4_xattr_ibody_find(inode, &i, &is); |
| 280 | if (error) |
| 281 | goto out; |
| 282 | |
| 283 | BUG_ON(!is.s.not_found); |
| 284 | |
| 285 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); |
| 286 | if (error) { |
| 287 | if (error == -ENOSPC) |
| 288 | ext4_clear_inode_state(inode, |
| 289 | EXT4_STATE_MAY_INLINE_DATA); |
| 290 | goto out; |
| 291 | } |
| 292 | |
| 293 | memset((void *)ext4_raw_inode(&is.iloc)->i_block, |
| 294 | 0, EXT4_MIN_INLINE_DATA_SIZE); |
| 295 | |
| 296 | EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here - |
| 297 | (void *)ext4_raw_inode(&is.iloc)); |
| 298 | EXT4_I(inode)->i_inline_size = len + EXT4_MIN_INLINE_DATA_SIZE; |
| 299 | ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); |
| 300 | ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA); |
| 301 | get_bh(is.iloc.bh); |
| 302 | error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); |
| 303 | |
| 304 | out: |
| 305 | brelse(is.iloc.bh); |
| 306 | return error; |
| 307 | } |
| 308 | |
| 309 | static int ext4_update_inline_data(handle_t *handle, struct inode *inode, |
| 310 | unsigned int len) |
| 311 | { |
| 312 | int error; |
| 313 | void *value = NULL; |
| 314 | struct ext4_xattr_ibody_find is = { |
| 315 | .s = { .not_found = -ENODATA, }, |
| 316 | }; |
| 317 | struct ext4_xattr_info i = { |
| 318 | .name_index = EXT4_XATTR_INDEX_SYSTEM, |
| 319 | .name = EXT4_XATTR_SYSTEM_DATA, |
| 320 | }; |
| 321 | |
| 322 | /* If the old space is ok, write the data directly. */ |
| 323 | if (len <= EXT4_I(inode)->i_inline_size) |
| 324 | return 0; |
| 325 | |
| 326 | error = ext4_get_inode_loc(inode, &is.iloc); |
| 327 | if (error) |
| 328 | return error; |
| 329 | |
| 330 | error = ext4_xattr_ibody_find(inode, &i, &is); |
| 331 | if (error) |
| 332 | goto out; |
| 333 | |
| 334 | BUG_ON(is.s.not_found); |
| 335 | |
| 336 | len -= EXT4_MIN_INLINE_DATA_SIZE; |
| 337 | value = kzalloc(len, GFP_NOFS); |
| 338 | if (!value) |
| 339 | goto out; |
| 340 | |
| 341 | error = ext4_xattr_ibody_get(inode, i.name_index, i.name, |
| 342 | value, len); |
| 343 | if (error == -ENODATA) |
| 344 | goto out; |
| 345 | |
| 346 | error = ext4_journal_get_write_access(handle, is.iloc.bh); |
| 347 | if (error) |
| 348 | goto out; |
| 349 | |
| 350 | /* Update the xttr entry. */ |
| 351 | i.value = value; |
| 352 | i.value_len = len; |
| 353 | |
| 354 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); |
| 355 | if (error) |
| 356 | goto out; |
| 357 | |
| 358 | EXT4_I(inode)->i_inline_off = (u16)((void *)is.s.here - |
| 359 | (void *)ext4_raw_inode(&is.iloc)); |
| 360 | EXT4_I(inode)->i_inline_size = EXT4_MIN_INLINE_DATA_SIZE + |
| 361 | le32_to_cpu(is.s.here->e_value_size); |
| 362 | ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); |
| 363 | get_bh(is.iloc.bh); |
| 364 | error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); |
| 365 | |
| 366 | out: |
| 367 | kfree(value); |
| 368 | brelse(is.iloc.bh); |
| 369 | return error; |
| 370 | } |
| 371 | |
| 372 | int ext4_prepare_inline_data(handle_t *handle, struct inode *inode, |
| 373 | unsigned int len) |
| 374 | { |
| 375 | int ret, size; |
| 376 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 377 | |
| 378 | if (!ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) |
| 379 | return -ENOSPC; |
| 380 | |
| 381 | size = ext4_get_max_inline_size(inode); |
| 382 | if (size < len) |
| 383 | return -ENOSPC; |
| 384 | |
| 385 | down_write(&EXT4_I(inode)->xattr_sem); |
| 386 | |
| 387 | if (ei->i_inline_off) |
| 388 | ret = ext4_update_inline_data(handle, inode, len); |
| 389 | else |
| 390 | ret = ext4_create_inline_data(handle, inode, len); |
| 391 | |
| 392 | up_write(&EXT4_I(inode)->xattr_sem); |
| 393 | |
| 394 | return ret; |
| 395 | } |
| 396 | |
| 397 | static int ext4_destroy_inline_data_nolock(handle_t *handle, |
| 398 | struct inode *inode) |
| 399 | { |
| 400 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 401 | struct ext4_xattr_ibody_find is = { |
| 402 | .s = { .not_found = 0, }, |
| 403 | }; |
| 404 | struct ext4_xattr_info i = { |
| 405 | .name_index = EXT4_XATTR_INDEX_SYSTEM, |
| 406 | .name = EXT4_XATTR_SYSTEM_DATA, |
| 407 | .value = NULL, |
| 408 | .value_len = 0, |
| 409 | }; |
| 410 | int error; |
| 411 | |
| 412 | if (!ei->i_inline_off) |
| 413 | return 0; |
| 414 | |
| 415 | error = ext4_get_inode_loc(inode, &is.iloc); |
| 416 | if (error) |
| 417 | return error; |
| 418 | |
| 419 | error = ext4_xattr_ibody_find(inode, &i, &is); |
| 420 | if (error) |
| 421 | goto out; |
| 422 | |
| 423 | error = ext4_journal_get_write_access(handle, is.iloc.bh); |
| 424 | if (error) |
| 425 | goto out; |
| 426 | |
| 427 | error = ext4_xattr_ibody_set(handle, inode, &i, &is); |
| 428 | if (error) |
| 429 | goto out; |
| 430 | |
| 431 | memset((void *)ext4_raw_inode(&is.iloc)->i_block, |
| 432 | 0, EXT4_MIN_INLINE_DATA_SIZE); |
| 433 | |
| 434 | if (EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb, |
| 435 | EXT4_FEATURE_INCOMPAT_EXTENTS)) { |
| 436 | if (S_ISDIR(inode->i_mode) || |
| 437 | S_ISREG(inode->i_mode) || S_ISLNK(inode->i_mode)) { |
| 438 | ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS); |
| 439 | ext4_ext_tree_init(handle, inode); |
| 440 | } |
| 441 | } |
| 442 | ext4_clear_inode_flag(inode, EXT4_INODE_INLINE_DATA); |
| 443 | |
| 444 | get_bh(is.iloc.bh); |
| 445 | error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); |
| 446 | |
| 447 | EXT4_I(inode)->i_inline_off = 0; |
| 448 | EXT4_I(inode)->i_inline_size = 0; |
| 449 | ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); |
| 450 | out: |
| 451 | brelse(is.iloc.bh); |
| 452 | if (error == -ENODATA) |
| 453 | error = 0; |
| 454 | return error; |
| 455 | } |
| 456 | |
| 457 | int ext4_destroy_inline_data(handle_t *handle, struct inode *inode) |
| 458 | { |
| 459 | int ret; |
| 460 | |
| 461 | down_write(&EXT4_I(inode)->xattr_sem); |
| 462 | ret = ext4_destroy_inline_data_nolock(handle, inode); |
| 463 | up_write(&EXT4_I(inode)->xattr_sem); |
| 464 | |
| 465 | return ret; |
| 466 | } |