Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com |
| 3 | * Written by Alex Tomas <alex@clusterfs.com> |
| 4 | * |
| 5 | * Architecture independence: |
| 6 | * Copyright (c) 2005, Bull S.A. |
| 7 | * Written by Pierre Peiffer <pierre.peiffer@bull.net> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 as |
| 11 | * published by the Free Software Foundation. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public Licens |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- |
| 21 | */ |
| 22 | |
| 23 | /* |
| 24 | * Extents support for EXT4 |
| 25 | * |
| 26 | * TODO: |
| 27 | * - ext4*_error() should be used in some situations |
| 28 | * - analyze all BUG()/BUG_ON(), use -EIO where appropriate |
| 29 | * - smart tree reduction |
| 30 | */ |
| 31 | |
| 32 | #include <linux/module.h> |
| 33 | #include <linux/fs.h> |
| 34 | #include <linux/time.h> |
| 35 | #include <linux/ext4_jbd2.h> |
| 36 | #include <linux/jbd.h> |
| 37 | #include <linux/smp_lock.h> |
| 38 | #include <linux/highuid.h> |
| 39 | #include <linux/pagemap.h> |
| 40 | #include <linux/quotaops.h> |
| 41 | #include <linux/string.h> |
| 42 | #include <linux/slab.h> |
| 43 | #include <linux/ext4_fs_extents.h> |
| 44 | #include <asm/uaccess.h> |
| 45 | |
| 46 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 47 | /* |
| 48 | * ext_pblock: |
| 49 | * combine low and high parts of physical block number into ext4_fsblk_t |
| 50 | */ |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 51 | static inline ext4_fsblk_t ext_pblock(struct ext4_extent *ex) |
| 52 | { |
| 53 | ext4_fsblk_t block; |
| 54 | |
| 55 | block = le32_to_cpu(ex->ee_start); |
| 56 | if (sizeof(ext4_fsblk_t) > 4) |
| 57 | block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1; |
| 58 | return block; |
| 59 | } |
| 60 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 61 | /* |
| 62 | * idx_pblock: |
| 63 | * combine low and high parts of a leaf physical block number into ext4_fsblk_t |
| 64 | */ |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 65 | static inline ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix) |
| 66 | { |
| 67 | ext4_fsblk_t block; |
| 68 | |
| 69 | block = le32_to_cpu(ix->ei_leaf); |
| 70 | if (sizeof(ext4_fsblk_t) > 4) |
| 71 | block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1; |
| 72 | return block; |
| 73 | } |
| 74 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 75 | /* |
| 76 | * ext4_ext_store_pblock: |
| 77 | * stores a large physical block number into an extent struct, |
| 78 | * breaking it into parts |
| 79 | */ |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 80 | static inline void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb) |
| 81 | { |
| 82 | ex->ee_start = cpu_to_le32((unsigned long) (pb & 0xffffffff)); |
| 83 | if (sizeof(ext4_fsblk_t) > 4) |
| 84 | ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); |
| 85 | } |
| 86 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 87 | /* |
| 88 | * ext4_idx_store_pblock: |
| 89 | * stores a large physical block number into an index struct, |
| 90 | * breaking it into parts |
| 91 | */ |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 92 | static inline void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb) |
| 93 | { |
| 94 | ix->ei_leaf = cpu_to_le32((unsigned long) (pb & 0xffffffff)); |
| 95 | if (sizeof(ext4_fsblk_t) > 4) |
| 96 | ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); |
| 97 | } |
| 98 | |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 99 | static int ext4_ext_check_header(const char *function, struct inode *inode, |
| 100 | struct ext4_extent_header *eh) |
| 101 | { |
| 102 | const char *error_msg = NULL; |
| 103 | |
| 104 | if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { |
| 105 | error_msg = "invalid magic"; |
| 106 | goto corrupted; |
| 107 | } |
| 108 | if (unlikely(eh->eh_max == 0)) { |
| 109 | error_msg = "invalid eh_max"; |
| 110 | goto corrupted; |
| 111 | } |
| 112 | if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { |
| 113 | error_msg = "invalid eh_entries"; |
| 114 | goto corrupted; |
| 115 | } |
| 116 | return 0; |
| 117 | |
| 118 | corrupted: |
| 119 | ext4_error(inode->i_sb, function, |
| 120 | "bad header in inode #%lu: %s - magic %x, " |
| 121 | "entries %u, max %u, depth %u", |
| 122 | inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic), |
| 123 | le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), |
| 124 | le16_to_cpu(eh->eh_depth)); |
| 125 | |
| 126 | return -EIO; |
| 127 | } |
| 128 | |
| 129 | static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed) |
| 130 | { |
| 131 | int err; |
| 132 | |
| 133 | if (handle->h_buffer_credits > needed) |
| 134 | return handle; |
| 135 | if (!ext4_journal_extend(handle, needed)) |
| 136 | return handle; |
| 137 | err = ext4_journal_restart(handle, needed); |
| 138 | |
| 139 | return handle; |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * could return: |
| 144 | * - EROFS |
| 145 | * - ENOMEM |
| 146 | */ |
| 147 | static int ext4_ext_get_access(handle_t *handle, struct inode *inode, |
| 148 | struct ext4_ext_path *path) |
| 149 | { |
| 150 | if (path->p_bh) { |
| 151 | /* path points to block */ |
| 152 | return ext4_journal_get_write_access(handle, path->p_bh); |
| 153 | } |
| 154 | /* path points to leaf/index in inode body */ |
| 155 | /* we use in-core data, no need to protect them */ |
| 156 | return 0; |
| 157 | } |
| 158 | |
| 159 | /* |
| 160 | * could return: |
| 161 | * - EROFS |
| 162 | * - ENOMEM |
| 163 | * - EIO |
| 164 | */ |
| 165 | static int ext4_ext_dirty(handle_t *handle, struct inode *inode, |
| 166 | struct ext4_ext_path *path) |
| 167 | { |
| 168 | int err; |
| 169 | if (path->p_bh) { |
| 170 | /* path points to block */ |
| 171 | err = ext4_journal_dirty_metadata(handle, path->p_bh); |
| 172 | } else { |
| 173 | /* path points to leaf/index in inode body */ |
| 174 | err = ext4_mark_inode_dirty(handle, inode); |
| 175 | } |
| 176 | return err; |
| 177 | } |
| 178 | |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 179 | static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 180 | struct ext4_ext_path *path, |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 181 | ext4_fsblk_t block) |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 182 | { |
| 183 | struct ext4_inode_info *ei = EXT4_I(inode); |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 184 | ext4_fsblk_t bg_start; |
| 185 | ext4_grpblk_t colour; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 186 | int depth; |
| 187 | |
| 188 | if (path) { |
| 189 | struct ext4_extent *ex; |
| 190 | depth = path->p_depth; |
| 191 | |
| 192 | /* try to predict block placement */ |
| 193 | if ((ex = path[depth].p_ext)) |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 194 | return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 195 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 196 | /* it looks like index is empty; |
| 197 | * try to find starting block from index itself */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 198 | if (path[depth].p_bh) |
| 199 | return path[depth].p_bh->b_blocknr; |
| 200 | } |
| 201 | |
| 202 | /* OK. use inode's group */ |
| 203 | bg_start = (ei->i_block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) + |
| 204 | le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block); |
| 205 | colour = (current->pid % 16) * |
| 206 | (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); |
| 207 | return bg_start + colour + block; |
| 208 | } |
| 209 | |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 210 | static ext4_fsblk_t |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 211 | ext4_ext_new_block(handle_t *handle, struct inode *inode, |
| 212 | struct ext4_ext_path *path, |
| 213 | struct ext4_extent *ex, int *err) |
| 214 | { |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 215 | ext4_fsblk_t goal, newblock; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 216 | |
| 217 | goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); |
| 218 | newblock = ext4_new_block(handle, inode, goal, err); |
| 219 | return newblock; |
| 220 | } |
| 221 | |
| 222 | static inline int ext4_ext_space_block(struct inode *inode) |
| 223 | { |
| 224 | int size; |
| 225 | |
| 226 | size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) |
| 227 | / sizeof(struct ext4_extent); |
| 228 | #ifdef AGRESSIVE_TEST |
| 229 | if (size > 6) |
| 230 | size = 6; |
| 231 | #endif |
| 232 | return size; |
| 233 | } |
| 234 | |
| 235 | static inline int ext4_ext_space_block_idx(struct inode *inode) |
| 236 | { |
| 237 | int size; |
| 238 | |
| 239 | size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) |
| 240 | / sizeof(struct ext4_extent_idx); |
| 241 | #ifdef AGRESSIVE_TEST |
| 242 | if (size > 5) |
| 243 | size = 5; |
| 244 | #endif |
| 245 | return size; |
| 246 | } |
| 247 | |
| 248 | static inline int ext4_ext_space_root(struct inode *inode) |
| 249 | { |
| 250 | int size; |
| 251 | |
| 252 | size = sizeof(EXT4_I(inode)->i_data); |
| 253 | size -= sizeof(struct ext4_extent_header); |
| 254 | size /= sizeof(struct ext4_extent); |
| 255 | #ifdef AGRESSIVE_TEST |
| 256 | if (size > 3) |
| 257 | size = 3; |
| 258 | #endif |
| 259 | return size; |
| 260 | } |
| 261 | |
| 262 | static inline int ext4_ext_space_root_idx(struct inode *inode) |
| 263 | { |
| 264 | int size; |
| 265 | |
| 266 | size = sizeof(EXT4_I(inode)->i_data); |
| 267 | size -= sizeof(struct ext4_extent_header); |
| 268 | size /= sizeof(struct ext4_extent_idx); |
| 269 | #ifdef AGRESSIVE_TEST |
| 270 | if (size > 4) |
| 271 | size = 4; |
| 272 | #endif |
| 273 | return size; |
| 274 | } |
| 275 | |
| 276 | #ifdef EXT_DEBUG |
| 277 | static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) |
| 278 | { |
| 279 | int k, l = path->p_depth; |
| 280 | |
| 281 | ext_debug("path:"); |
| 282 | for (k = 0; k <= l; k++, path++) { |
| 283 | if (path->p_idx) { |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 284 | ext_debug(" %d->"E3FSBLK, le32_to_cpu(path->p_idx->ei_block), |
| 285 | idx_pblock(path->p_idx)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 286 | } else if (path->p_ext) { |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 287 | ext_debug(" %d:%d:"E3FSBLK" ", |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 288 | le32_to_cpu(path->p_ext->ee_block), |
| 289 | le16_to_cpu(path->p_ext->ee_len), |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 290 | ext_pblock(path->p_ext)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 291 | } else |
| 292 | ext_debug(" []"); |
| 293 | } |
| 294 | ext_debug("\n"); |
| 295 | } |
| 296 | |
| 297 | static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) |
| 298 | { |
| 299 | int depth = ext_depth(inode); |
| 300 | struct ext4_extent_header *eh; |
| 301 | struct ext4_extent *ex; |
| 302 | int i; |
| 303 | |
| 304 | if (!path) |
| 305 | return; |
| 306 | |
| 307 | eh = path[depth].p_hdr; |
| 308 | ex = EXT_FIRST_EXTENT(eh); |
| 309 | |
| 310 | for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 311 | ext_debug("%d:%d:"E3FSBLK" ", le32_to_cpu(ex->ee_block), |
| 312 | le16_to_cpu(ex->ee_len), ext_pblock(ex)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 313 | } |
| 314 | ext_debug("\n"); |
| 315 | } |
| 316 | #else |
| 317 | #define ext4_ext_show_path(inode,path) |
| 318 | #define ext4_ext_show_leaf(inode,path) |
| 319 | #endif |
| 320 | |
| 321 | static void ext4_ext_drop_refs(struct ext4_ext_path *path) |
| 322 | { |
| 323 | int depth = path->p_depth; |
| 324 | int i; |
| 325 | |
| 326 | for (i = 0; i <= depth; i++, path++) |
| 327 | if (path->p_bh) { |
| 328 | brelse(path->p_bh); |
| 329 | path->p_bh = NULL; |
| 330 | } |
| 331 | } |
| 332 | |
| 333 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 334 | * ext4_ext_binsearch_idx: |
| 335 | * binary search for the closest index of the given block |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 336 | */ |
| 337 | static void |
| 338 | ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block) |
| 339 | { |
| 340 | struct ext4_extent_header *eh = path->p_hdr; |
| 341 | struct ext4_extent_idx *r, *l, *m; |
| 342 | |
| 343 | BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); |
| 344 | BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); |
| 345 | BUG_ON(le16_to_cpu(eh->eh_entries) <= 0); |
| 346 | |
| 347 | ext_debug("binsearch for %d(idx): ", block); |
| 348 | |
| 349 | l = EXT_FIRST_INDEX(eh) + 1; |
| 350 | r = EXT_FIRST_INDEX(eh) + le16_to_cpu(eh->eh_entries) - 1; |
| 351 | while (l <= r) { |
| 352 | m = l + (r - l) / 2; |
| 353 | if (block < le32_to_cpu(m->ei_block)) |
| 354 | r = m - 1; |
| 355 | else |
| 356 | l = m + 1; |
| 357 | ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ei_block, |
| 358 | m, m->ei_block, r, r->ei_block); |
| 359 | } |
| 360 | |
| 361 | path->p_idx = l - 1; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 362 | ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block), |
| 363 | idx_block(path->p_idx)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 364 | |
| 365 | #ifdef CHECK_BINSEARCH |
| 366 | { |
| 367 | struct ext4_extent_idx *chix, *ix; |
| 368 | int k; |
| 369 | |
| 370 | chix = ix = EXT_FIRST_INDEX(eh); |
| 371 | for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { |
| 372 | if (k != 0 && |
| 373 | le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { |
| 374 | printk("k=%d, ix=0x%p, first=0x%p\n", k, |
| 375 | ix, EXT_FIRST_INDEX(eh)); |
| 376 | printk("%u <= %u\n", |
| 377 | le32_to_cpu(ix->ei_block), |
| 378 | le32_to_cpu(ix[-1].ei_block)); |
| 379 | } |
| 380 | BUG_ON(k && le32_to_cpu(ix->ei_block) |
| 381 | <= le32_to_cpu(ix[-1].ei_block)); |
| 382 | if (block < le32_to_cpu(ix->ei_block)) |
| 383 | break; |
| 384 | chix = ix; |
| 385 | } |
| 386 | BUG_ON(chix != path->p_idx); |
| 387 | } |
| 388 | #endif |
| 389 | |
| 390 | } |
| 391 | |
| 392 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 393 | * ext4_ext_binsearch: |
| 394 | * binary search for closest extent of the given block |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 395 | */ |
| 396 | static void |
| 397 | ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block) |
| 398 | { |
| 399 | struct ext4_extent_header *eh = path->p_hdr; |
| 400 | struct ext4_extent *r, *l, *m; |
| 401 | |
| 402 | BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); |
| 403 | BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); |
| 404 | |
| 405 | if (eh->eh_entries == 0) { |
| 406 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 407 | * this leaf is empty: |
| 408 | * we get such a leaf in split/add case |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 409 | */ |
| 410 | return; |
| 411 | } |
| 412 | |
| 413 | ext_debug("binsearch for %d: ", block); |
| 414 | |
| 415 | l = EXT_FIRST_EXTENT(eh) + 1; |
| 416 | r = EXT_FIRST_EXTENT(eh) + le16_to_cpu(eh->eh_entries) - 1; |
| 417 | |
| 418 | while (l <= r) { |
| 419 | m = l + (r - l) / 2; |
| 420 | if (block < le32_to_cpu(m->ee_block)) |
| 421 | r = m - 1; |
| 422 | else |
| 423 | l = m + 1; |
| 424 | ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ee_block, |
| 425 | m, m->ee_block, r, r->ee_block); |
| 426 | } |
| 427 | |
| 428 | path->p_ext = l - 1; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 429 | ext_debug(" -> %d:"E3FSBLK":%d ", |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 430 | le32_to_cpu(path->p_ext->ee_block), |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 431 | ext_pblock(path->p_ext), |
| 432 | le16_to_cpu(path->p_ext->ee_len)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 433 | |
| 434 | #ifdef CHECK_BINSEARCH |
| 435 | { |
| 436 | struct ext4_extent *chex, *ex; |
| 437 | int k; |
| 438 | |
| 439 | chex = ex = EXT_FIRST_EXTENT(eh); |
| 440 | for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { |
| 441 | BUG_ON(k && le32_to_cpu(ex->ee_block) |
| 442 | <= le32_to_cpu(ex[-1].ee_block)); |
| 443 | if (block < le32_to_cpu(ex->ee_block)) |
| 444 | break; |
| 445 | chex = ex; |
| 446 | } |
| 447 | BUG_ON(chex != path->p_ext); |
| 448 | } |
| 449 | #endif |
| 450 | |
| 451 | } |
| 452 | |
| 453 | int ext4_ext_tree_init(handle_t *handle, struct inode *inode) |
| 454 | { |
| 455 | struct ext4_extent_header *eh; |
| 456 | |
| 457 | eh = ext_inode_hdr(inode); |
| 458 | eh->eh_depth = 0; |
| 459 | eh->eh_entries = 0; |
| 460 | eh->eh_magic = EXT4_EXT_MAGIC; |
| 461 | eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode)); |
| 462 | ext4_mark_inode_dirty(handle, inode); |
| 463 | ext4_ext_invalidate_cache(inode); |
| 464 | return 0; |
| 465 | } |
| 466 | |
| 467 | struct ext4_ext_path * |
| 468 | ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path) |
| 469 | { |
| 470 | struct ext4_extent_header *eh; |
| 471 | struct buffer_head *bh; |
| 472 | short int depth, i, ppos = 0, alloc = 0; |
| 473 | |
| 474 | eh = ext_inode_hdr(inode); |
| 475 | BUG_ON(eh == NULL); |
| 476 | if (ext4_ext_check_header(__FUNCTION__, inode, eh)) |
| 477 | return ERR_PTR(-EIO); |
| 478 | |
| 479 | i = depth = ext_depth(inode); |
| 480 | |
| 481 | /* account possible depth increase */ |
| 482 | if (!path) { |
| 483 | path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 2), |
| 484 | GFP_NOFS); |
| 485 | if (!path) |
| 486 | return ERR_PTR(-ENOMEM); |
| 487 | alloc = 1; |
| 488 | } |
| 489 | memset(path, 0, sizeof(struct ext4_ext_path) * (depth + 1)); |
| 490 | path[0].p_hdr = eh; |
| 491 | |
| 492 | /* walk through the tree */ |
| 493 | while (i) { |
| 494 | ext_debug("depth %d: num %d, max %d\n", |
| 495 | ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); |
| 496 | ext4_ext_binsearch_idx(inode, path + ppos, block); |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 497 | path[ppos].p_block = idx_pblock(path[ppos].p_idx); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 498 | path[ppos].p_depth = i; |
| 499 | path[ppos].p_ext = NULL; |
| 500 | |
| 501 | bh = sb_bread(inode->i_sb, path[ppos].p_block); |
| 502 | if (!bh) |
| 503 | goto err; |
| 504 | |
| 505 | eh = ext_block_hdr(bh); |
| 506 | ppos++; |
| 507 | BUG_ON(ppos > depth); |
| 508 | path[ppos].p_bh = bh; |
| 509 | path[ppos].p_hdr = eh; |
| 510 | i--; |
| 511 | |
| 512 | if (ext4_ext_check_header(__FUNCTION__, inode, eh)) |
| 513 | goto err; |
| 514 | } |
| 515 | |
| 516 | path[ppos].p_depth = i; |
| 517 | path[ppos].p_hdr = eh; |
| 518 | path[ppos].p_ext = NULL; |
| 519 | path[ppos].p_idx = NULL; |
| 520 | |
| 521 | if (ext4_ext_check_header(__FUNCTION__, inode, eh)) |
| 522 | goto err; |
| 523 | |
| 524 | /* find extent */ |
| 525 | ext4_ext_binsearch(inode, path + ppos, block); |
| 526 | |
| 527 | ext4_ext_show_path(inode, path); |
| 528 | |
| 529 | return path; |
| 530 | |
| 531 | err: |
| 532 | ext4_ext_drop_refs(path); |
| 533 | if (alloc) |
| 534 | kfree(path); |
| 535 | return ERR_PTR(-EIO); |
| 536 | } |
| 537 | |
| 538 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 539 | * ext4_ext_insert_index: |
| 540 | * insert new index [@logical;@ptr] into the block at @curp; |
| 541 | * check where to insert: before @curp or after @curp |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 542 | */ |
| 543 | static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, |
| 544 | struct ext4_ext_path *curp, |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 545 | int logical, ext4_fsblk_t ptr) |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 546 | { |
| 547 | struct ext4_extent_idx *ix; |
| 548 | int len, err; |
| 549 | |
| 550 | if ((err = ext4_ext_get_access(handle, inode, curp))) |
| 551 | return err; |
| 552 | |
| 553 | BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block)); |
| 554 | len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx; |
| 555 | if (logical > le32_to_cpu(curp->p_idx->ei_block)) { |
| 556 | /* insert after */ |
| 557 | if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) { |
| 558 | len = (len - 1) * sizeof(struct ext4_extent_idx); |
| 559 | len = len < 0 ? 0 : len; |
| 560 | ext_debug("insert new index %d after: %d. " |
| 561 | "move %d from 0x%p to 0x%p\n", |
| 562 | logical, ptr, len, |
| 563 | (curp->p_idx + 1), (curp->p_idx + 2)); |
| 564 | memmove(curp->p_idx + 2, curp->p_idx + 1, len); |
| 565 | } |
| 566 | ix = curp->p_idx + 1; |
| 567 | } else { |
| 568 | /* insert before */ |
| 569 | len = len * sizeof(struct ext4_extent_idx); |
| 570 | len = len < 0 ? 0 : len; |
| 571 | ext_debug("insert new index %d before: %d. " |
| 572 | "move %d from 0x%p to 0x%p\n", |
| 573 | logical, ptr, len, |
| 574 | curp->p_idx, (curp->p_idx + 1)); |
| 575 | memmove(curp->p_idx + 1, curp->p_idx, len); |
| 576 | ix = curp->p_idx; |
| 577 | } |
| 578 | |
| 579 | ix->ei_block = cpu_to_le32(logical); |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 580 | ext4_idx_store_pblock(ix, ptr); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 581 | curp->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(curp->p_hdr->eh_entries)+1); |
| 582 | |
| 583 | BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries) |
| 584 | > le16_to_cpu(curp->p_hdr->eh_max)); |
| 585 | BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr)); |
| 586 | |
| 587 | err = ext4_ext_dirty(handle, inode, curp); |
| 588 | ext4_std_error(inode->i_sb, err); |
| 589 | |
| 590 | return err; |
| 591 | } |
| 592 | |
| 593 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 594 | * ext4_ext_split: |
| 595 | * inserts new subtree into the path, using free index entry |
| 596 | * at depth @at: |
| 597 | * - allocates all needed blocks (new leaf and all intermediate index blocks) |
| 598 | * - makes decision where to split |
| 599 | * - moves remaining extents and index entries (right to the split point) |
| 600 | * into the newly allocated blocks |
| 601 | * - initializes subtree |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 602 | */ |
| 603 | static int ext4_ext_split(handle_t *handle, struct inode *inode, |
| 604 | struct ext4_ext_path *path, |
| 605 | struct ext4_extent *newext, int at) |
| 606 | { |
| 607 | struct buffer_head *bh = NULL; |
| 608 | int depth = ext_depth(inode); |
| 609 | struct ext4_extent_header *neh; |
| 610 | struct ext4_extent_idx *fidx; |
| 611 | struct ext4_extent *ex; |
| 612 | int i = at, k, m, a; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 613 | ext4_fsblk_t newblock, oldblock; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 614 | __le32 border; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 615 | ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 616 | int err = 0; |
| 617 | |
| 618 | /* make decision: where to split? */ |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 619 | /* FIXME: now decision is simplest: at current extent */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 620 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 621 | /* if current leaf will be split, then we should use |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 622 | * border from split point */ |
| 623 | BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr)); |
| 624 | if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { |
| 625 | border = path[depth].p_ext[1].ee_block; |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 626 | ext_debug("leaf will be split." |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 627 | " next leaf starts at %d\n", |
| 628 | le32_to_cpu(border)); |
| 629 | } else { |
| 630 | border = newext->ee_block; |
| 631 | ext_debug("leaf will be added." |
| 632 | " next leaf starts at %d\n", |
| 633 | le32_to_cpu(border)); |
| 634 | } |
| 635 | |
| 636 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 637 | * If error occurs, then we break processing |
| 638 | * and mark filesystem read-only. index won't |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 639 | * be inserted and tree will be in consistent |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 640 | * state. Next mount will repair buffers too. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 641 | */ |
| 642 | |
| 643 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 644 | * Get array to track all allocated blocks. |
| 645 | * We need this to handle errors and free blocks |
| 646 | * upon them. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 647 | */ |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 648 | ablocks = kmalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 649 | if (!ablocks) |
| 650 | return -ENOMEM; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 651 | memset(ablocks, 0, sizeof(ext4_fsblk_t) * depth); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 652 | |
| 653 | /* allocate all needed blocks */ |
| 654 | ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); |
| 655 | for (a = 0; a < depth - at; a++) { |
| 656 | newblock = ext4_ext_new_block(handle, inode, path, newext, &err); |
| 657 | if (newblock == 0) |
| 658 | goto cleanup; |
| 659 | ablocks[a] = newblock; |
| 660 | } |
| 661 | |
| 662 | /* initialize new leaf */ |
| 663 | newblock = ablocks[--a]; |
| 664 | BUG_ON(newblock == 0); |
| 665 | bh = sb_getblk(inode->i_sb, newblock); |
| 666 | if (!bh) { |
| 667 | err = -EIO; |
| 668 | goto cleanup; |
| 669 | } |
| 670 | lock_buffer(bh); |
| 671 | |
| 672 | if ((err = ext4_journal_get_create_access(handle, bh))) |
| 673 | goto cleanup; |
| 674 | |
| 675 | neh = ext_block_hdr(bh); |
| 676 | neh->eh_entries = 0; |
| 677 | neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); |
| 678 | neh->eh_magic = EXT4_EXT_MAGIC; |
| 679 | neh->eh_depth = 0; |
| 680 | ex = EXT_FIRST_EXTENT(neh); |
| 681 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 682 | /* move remainder of path[depth] to the new leaf */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 683 | BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max); |
| 684 | /* start copy from next extent */ |
| 685 | /* TODO: we could do it by single memmove */ |
| 686 | m = 0; |
| 687 | path[depth].p_ext++; |
| 688 | while (path[depth].p_ext <= |
| 689 | EXT_MAX_EXTENT(path[depth].p_hdr)) { |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 690 | ext_debug("move %d:"E3FSBLK":%d in new leaf "E3FSBLK"\n", |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 691 | le32_to_cpu(path[depth].p_ext->ee_block), |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 692 | ext_pblock(path[depth].p_ext), |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 693 | le16_to_cpu(path[depth].p_ext->ee_len), |
| 694 | newblock); |
| 695 | /*memmove(ex++, path[depth].p_ext++, |
| 696 | sizeof(struct ext4_extent)); |
| 697 | neh->eh_entries++;*/ |
| 698 | path[depth].p_ext++; |
| 699 | m++; |
| 700 | } |
| 701 | if (m) { |
| 702 | memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m); |
| 703 | neh->eh_entries = cpu_to_le16(le16_to_cpu(neh->eh_entries)+m); |
| 704 | } |
| 705 | |
| 706 | set_buffer_uptodate(bh); |
| 707 | unlock_buffer(bh); |
| 708 | |
| 709 | if ((err = ext4_journal_dirty_metadata(handle, bh))) |
| 710 | goto cleanup; |
| 711 | brelse(bh); |
| 712 | bh = NULL; |
| 713 | |
| 714 | /* correct old leaf */ |
| 715 | if (m) { |
| 716 | if ((err = ext4_ext_get_access(handle, inode, path + depth))) |
| 717 | goto cleanup; |
| 718 | path[depth].p_hdr->eh_entries = |
| 719 | cpu_to_le16(le16_to_cpu(path[depth].p_hdr->eh_entries)-m); |
| 720 | if ((err = ext4_ext_dirty(handle, inode, path + depth))) |
| 721 | goto cleanup; |
| 722 | |
| 723 | } |
| 724 | |
| 725 | /* create intermediate indexes */ |
| 726 | k = depth - at - 1; |
| 727 | BUG_ON(k < 0); |
| 728 | if (k) |
| 729 | ext_debug("create %d intermediate indices\n", k); |
| 730 | /* insert new index into current index block */ |
| 731 | /* current depth stored in i var */ |
| 732 | i = depth - 1; |
| 733 | while (k--) { |
| 734 | oldblock = newblock; |
| 735 | newblock = ablocks[--a]; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 736 | bh = sb_getblk(inode->i_sb, (ext4_fsblk_t)newblock); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 737 | if (!bh) { |
| 738 | err = -EIO; |
| 739 | goto cleanup; |
| 740 | } |
| 741 | lock_buffer(bh); |
| 742 | |
| 743 | if ((err = ext4_journal_get_create_access(handle, bh))) |
| 744 | goto cleanup; |
| 745 | |
| 746 | neh = ext_block_hdr(bh); |
| 747 | neh->eh_entries = cpu_to_le16(1); |
| 748 | neh->eh_magic = EXT4_EXT_MAGIC; |
| 749 | neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); |
| 750 | neh->eh_depth = cpu_to_le16(depth - i); |
| 751 | fidx = EXT_FIRST_INDEX(neh); |
| 752 | fidx->ei_block = border; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 753 | ext4_idx_store_pblock(fidx, oldblock); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 754 | |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 755 | ext_debug("int.index at %d (block "E3FSBLK"): %lu -> "E3FSBLK"\n", i, |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 756 | newblock, (unsigned long) le32_to_cpu(border), |
| 757 | oldblock); |
| 758 | /* copy indexes */ |
| 759 | m = 0; |
| 760 | path[i].p_idx++; |
| 761 | |
| 762 | ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, |
| 763 | EXT_MAX_INDEX(path[i].p_hdr)); |
| 764 | BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) != |
| 765 | EXT_LAST_INDEX(path[i].p_hdr)); |
| 766 | while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) { |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 767 | ext_debug("%d: move %d:%d in new index "E3FSBLK"\n", i, |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 768 | le32_to_cpu(path[i].p_idx->ei_block), |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 769 | idx_pblock(path[i].p_idx), |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 770 | newblock); |
| 771 | /*memmove(++fidx, path[i].p_idx++, |
| 772 | sizeof(struct ext4_extent_idx)); |
| 773 | neh->eh_entries++; |
| 774 | BUG_ON(neh->eh_entries > neh->eh_max);*/ |
| 775 | path[i].p_idx++; |
| 776 | m++; |
| 777 | } |
| 778 | if (m) { |
| 779 | memmove(++fidx, path[i].p_idx - m, |
| 780 | sizeof(struct ext4_extent_idx) * m); |
| 781 | neh->eh_entries = |
| 782 | cpu_to_le16(le16_to_cpu(neh->eh_entries) + m); |
| 783 | } |
| 784 | set_buffer_uptodate(bh); |
| 785 | unlock_buffer(bh); |
| 786 | |
| 787 | if ((err = ext4_journal_dirty_metadata(handle, bh))) |
| 788 | goto cleanup; |
| 789 | brelse(bh); |
| 790 | bh = NULL; |
| 791 | |
| 792 | /* correct old index */ |
| 793 | if (m) { |
| 794 | err = ext4_ext_get_access(handle, inode, path + i); |
| 795 | if (err) |
| 796 | goto cleanup; |
| 797 | path[i].p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path[i].p_hdr->eh_entries)-m); |
| 798 | err = ext4_ext_dirty(handle, inode, path + i); |
| 799 | if (err) |
| 800 | goto cleanup; |
| 801 | } |
| 802 | |
| 803 | i--; |
| 804 | } |
| 805 | |
| 806 | /* insert new index */ |
| 807 | if (err) |
| 808 | goto cleanup; |
| 809 | |
| 810 | err = ext4_ext_insert_index(handle, inode, path + at, |
| 811 | le32_to_cpu(border), newblock); |
| 812 | |
| 813 | cleanup: |
| 814 | if (bh) { |
| 815 | if (buffer_locked(bh)) |
| 816 | unlock_buffer(bh); |
| 817 | brelse(bh); |
| 818 | } |
| 819 | |
| 820 | if (err) { |
| 821 | /* free all allocated blocks in error case */ |
| 822 | for (i = 0; i < depth; i++) { |
| 823 | if (!ablocks[i]) |
| 824 | continue; |
| 825 | ext4_free_blocks(handle, inode, ablocks[i], 1); |
| 826 | } |
| 827 | } |
| 828 | kfree(ablocks); |
| 829 | |
| 830 | return err; |
| 831 | } |
| 832 | |
| 833 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 834 | * ext4_ext_grow_indepth: |
| 835 | * implements tree growing procedure: |
| 836 | * - allocates new block |
| 837 | * - moves top-level data (index block or leaf) into the new block |
| 838 | * - initializes new top-level, creating index that points to the |
| 839 | * just created block |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 840 | */ |
| 841 | static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, |
| 842 | struct ext4_ext_path *path, |
| 843 | struct ext4_extent *newext) |
| 844 | { |
| 845 | struct ext4_ext_path *curp = path; |
| 846 | struct ext4_extent_header *neh; |
| 847 | struct ext4_extent_idx *fidx; |
| 848 | struct buffer_head *bh; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 849 | ext4_fsblk_t newblock; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 850 | int err = 0; |
| 851 | |
| 852 | newblock = ext4_ext_new_block(handle, inode, path, newext, &err); |
| 853 | if (newblock == 0) |
| 854 | return err; |
| 855 | |
| 856 | bh = sb_getblk(inode->i_sb, newblock); |
| 857 | if (!bh) { |
| 858 | err = -EIO; |
| 859 | ext4_std_error(inode->i_sb, err); |
| 860 | return err; |
| 861 | } |
| 862 | lock_buffer(bh); |
| 863 | |
| 864 | if ((err = ext4_journal_get_create_access(handle, bh))) { |
| 865 | unlock_buffer(bh); |
| 866 | goto out; |
| 867 | } |
| 868 | |
| 869 | /* move top-level index/leaf into new block */ |
| 870 | memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data)); |
| 871 | |
| 872 | /* set size of new block */ |
| 873 | neh = ext_block_hdr(bh); |
| 874 | /* old root could have indexes or leaves |
| 875 | * so calculate e_max right way */ |
| 876 | if (ext_depth(inode)) |
| 877 | neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); |
| 878 | else |
| 879 | neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); |
| 880 | neh->eh_magic = EXT4_EXT_MAGIC; |
| 881 | set_buffer_uptodate(bh); |
| 882 | unlock_buffer(bh); |
| 883 | |
| 884 | if ((err = ext4_journal_dirty_metadata(handle, bh))) |
| 885 | goto out; |
| 886 | |
| 887 | /* create index in new top-level index: num,max,pointer */ |
| 888 | if ((err = ext4_ext_get_access(handle, inode, curp))) |
| 889 | goto out; |
| 890 | |
| 891 | curp->p_hdr->eh_magic = EXT4_EXT_MAGIC; |
| 892 | curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode)); |
| 893 | curp->p_hdr->eh_entries = cpu_to_le16(1); |
| 894 | curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr); |
| 895 | /* FIXME: it works, but actually path[0] can be index */ |
| 896 | curp->p_idx->ei_block = EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 897 | ext4_idx_store_pblock(curp->p_idx, newblock); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 898 | |
| 899 | neh = ext_inode_hdr(inode); |
| 900 | fidx = EXT_FIRST_INDEX(neh); |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 901 | ext_debug("new root: num %d(%d), lblock %d, ptr "E3FSBLK"\n", |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 902 | le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 903 | le32_to_cpu(fidx->ei_block), idx_pblock(fidx)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 904 | |
| 905 | neh->eh_depth = cpu_to_le16(path->p_depth + 1); |
| 906 | err = ext4_ext_dirty(handle, inode, curp); |
| 907 | out: |
| 908 | brelse(bh); |
| 909 | |
| 910 | return err; |
| 911 | } |
| 912 | |
| 913 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 914 | * ext4_ext_create_new_leaf: |
| 915 | * finds empty index and adds new leaf. |
| 916 | * if no free index is found, then it requests in-depth growing. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 917 | */ |
| 918 | static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, |
| 919 | struct ext4_ext_path *path, |
| 920 | struct ext4_extent *newext) |
| 921 | { |
| 922 | struct ext4_ext_path *curp; |
| 923 | int depth, i, err = 0; |
| 924 | |
| 925 | repeat: |
| 926 | i = depth = ext_depth(inode); |
| 927 | |
| 928 | /* walk up to the tree and look for free index entry */ |
| 929 | curp = path + depth; |
| 930 | while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { |
| 931 | i--; |
| 932 | curp--; |
| 933 | } |
| 934 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 935 | /* we use already allocated block for index block, |
| 936 | * so subsequent data blocks should be contiguous */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 937 | if (EXT_HAS_FREE_INDEX(curp)) { |
| 938 | /* if we found index with free entry, then use that |
| 939 | * entry: create all needed subtree and add new leaf */ |
| 940 | err = ext4_ext_split(handle, inode, path, newext, i); |
| 941 | |
| 942 | /* refill path */ |
| 943 | ext4_ext_drop_refs(path); |
| 944 | path = ext4_ext_find_extent(inode, |
| 945 | le32_to_cpu(newext->ee_block), |
| 946 | path); |
| 947 | if (IS_ERR(path)) |
| 948 | err = PTR_ERR(path); |
| 949 | } else { |
| 950 | /* tree is full, time to grow in depth */ |
| 951 | err = ext4_ext_grow_indepth(handle, inode, path, newext); |
| 952 | if (err) |
| 953 | goto out; |
| 954 | |
| 955 | /* refill path */ |
| 956 | ext4_ext_drop_refs(path); |
| 957 | path = ext4_ext_find_extent(inode, |
| 958 | le32_to_cpu(newext->ee_block), |
| 959 | path); |
| 960 | if (IS_ERR(path)) { |
| 961 | err = PTR_ERR(path); |
| 962 | goto out; |
| 963 | } |
| 964 | |
| 965 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 966 | * only first (depth 0 -> 1) produces free space; |
| 967 | * in all other cases we have to split the grown tree |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 968 | */ |
| 969 | depth = ext_depth(inode); |
| 970 | if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 971 | /* now we need to split */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 972 | goto repeat; |
| 973 | } |
| 974 | } |
| 975 | |
| 976 | out: |
| 977 | return err; |
| 978 | } |
| 979 | |
| 980 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 981 | * ext4_ext_next_allocated_block: |
| 982 | * returns allocated block in subsequent extent or EXT_MAX_BLOCK. |
| 983 | * NOTE: it considers block number from index entry as |
| 984 | * allocated block. Thus, index entries have to be consistent |
| 985 | * with leaves. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 986 | */ |
| 987 | static unsigned long |
| 988 | ext4_ext_next_allocated_block(struct ext4_ext_path *path) |
| 989 | { |
| 990 | int depth; |
| 991 | |
| 992 | BUG_ON(path == NULL); |
| 993 | depth = path->p_depth; |
| 994 | |
| 995 | if (depth == 0 && path->p_ext == NULL) |
| 996 | return EXT_MAX_BLOCK; |
| 997 | |
| 998 | while (depth >= 0) { |
| 999 | if (depth == path->p_depth) { |
| 1000 | /* leaf */ |
| 1001 | if (path[depth].p_ext != |
| 1002 | EXT_LAST_EXTENT(path[depth].p_hdr)) |
| 1003 | return le32_to_cpu(path[depth].p_ext[1].ee_block); |
| 1004 | } else { |
| 1005 | /* index */ |
| 1006 | if (path[depth].p_idx != |
| 1007 | EXT_LAST_INDEX(path[depth].p_hdr)) |
| 1008 | return le32_to_cpu(path[depth].p_idx[1].ei_block); |
| 1009 | } |
| 1010 | depth--; |
| 1011 | } |
| 1012 | |
| 1013 | return EXT_MAX_BLOCK; |
| 1014 | } |
| 1015 | |
| 1016 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1017 | * ext4_ext_next_leaf_block: |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1018 | * returns first allocated block from next leaf or EXT_MAX_BLOCK |
| 1019 | */ |
| 1020 | static unsigned ext4_ext_next_leaf_block(struct inode *inode, |
| 1021 | struct ext4_ext_path *path) |
| 1022 | { |
| 1023 | int depth; |
| 1024 | |
| 1025 | BUG_ON(path == NULL); |
| 1026 | depth = path->p_depth; |
| 1027 | |
| 1028 | /* zero-tree has no leaf blocks at all */ |
| 1029 | if (depth == 0) |
| 1030 | return EXT_MAX_BLOCK; |
| 1031 | |
| 1032 | /* go to index block */ |
| 1033 | depth--; |
| 1034 | |
| 1035 | while (depth >= 0) { |
| 1036 | if (path[depth].p_idx != |
| 1037 | EXT_LAST_INDEX(path[depth].p_hdr)) |
| 1038 | return le32_to_cpu(path[depth].p_idx[1].ei_block); |
| 1039 | depth--; |
| 1040 | } |
| 1041 | |
| 1042 | return EXT_MAX_BLOCK; |
| 1043 | } |
| 1044 | |
| 1045 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1046 | * ext4_ext_correct_indexes: |
| 1047 | * if leaf gets modified and modified extent is first in the leaf, |
| 1048 | * then we have to correct all indexes above. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1049 | * TODO: do we need to correct tree in all cases? |
| 1050 | */ |
| 1051 | int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, |
| 1052 | struct ext4_ext_path *path) |
| 1053 | { |
| 1054 | struct ext4_extent_header *eh; |
| 1055 | int depth = ext_depth(inode); |
| 1056 | struct ext4_extent *ex; |
| 1057 | __le32 border; |
| 1058 | int k, err = 0; |
| 1059 | |
| 1060 | eh = path[depth].p_hdr; |
| 1061 | ex = path[depth].p_ext; |
| 1062 | BUG_ON(ex == NULL); |
| 1063 | BUG_ON(eh == NULL); |
| 1064 | |
| 1065 | if (depth == 0) { |
| 1066 | /* there is no tree at all */ |
| 1067 | return 0; |
| 1068 | } |
| 1069 | |
| 1070 | if (ex != EXT_FIRST_EXTENT(eh)) { |
| 1071 | /* we correct tree if first leaf got modified only */ |
| 1072 | return 0; |
| 1073 | } |
| 1074 | |
| 1075 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1076 | * TODO: we need correction if border is smaller than current one |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1077 | */ |
| 1078 | k = depth - 1; |
| 1079 | border = path[depth].p_ext->ee_block; |
| 1080 | if ((err = ext4_ext_get_access(handle, inode, path + k))) |
| 1081 | return err; |
| 1082 | path[k].p_idx->ei_block = border; |
| 1083 | if ((err = ext4_ext_dirty(handle, inode, path + k))) |
| 1084 | return err; |
| 1085 | |
| 1086 | while (k--) { |
| 1087 | /* change all left-side indexes */ |
| 1088 | if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) |
| 1089 | break; |
| 1090 | if ((err = ext4_ext_get_access(handle, inode, path + k))) |
| 1091 | break; |
| 1092 | path[k].p_idx->ei_block = border; |
| 1093 | if ((err = ext4_ext_dirty(handle, inode, path + k))) |
| 1094 | break; |
| 1095 | } |
| 1096 | |
| 1097 | return err; |
| 1098 | } |
| 1099 | |
| 1100 | static int inline |
| 1101 | ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, |
| 1102 | struct ext4_extent *ex2) |
| 1103 | { |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1104 | if (le32_to_cpu(ex1->ee_block) + le16_to_cpu(ex1->ee_len) |
| 1105 | != le32_to_cpu(ex2->ee_block)) |
| 1106 | return 0; |
| 1107 | |
Suparna Bhattacharya | 471d401 | 2006-10-11 01:21:06 -0700 | [diff] [blame] | 1108 | /* |
| 1109 | * To allow future support for preallocated extents to be added |
| 1110 | * as an RO_COMPAT feature, refuse to merge to extents if |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1111 | * this can result in the top bit of ee_len being set. |
Suparna Bhattacharya | 471d401 | 2006-10-11 01:21:06 -0700 | [diff] [blame] | 1112 | */ |
| 1113 | if (le16_to_cpu(ex1->ee_len) + le16_to_cpu(ex2->ee_len) > EXT_MAX_LEN) |
| 1114 | return 0; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1115 | #ifdef AGRESSIVE_TEST |
| 1116 | if (le16_to_cpu(ex1->ee_len) >= 4) |
| 1117 | return 0; |
| 1118 | #endif |
| 1119 | |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1120 | if (ext_pblock(ex1) + le16_to_cpu(ex1->ee_len) == ext_pblock(ex2)) |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1121 | return 1; |
| 1122 | return 0; |
| 1123 | } |
| 1124 | |
| 1125 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1126 | * ext4_ext_insert_extent: |
| 1127 | * tries to merge requsted extent into the existing extent or |
| 1128 | * inserts requested extent as new one into the tree, |
| 1129 | * creating new leaf in the no-space case. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1130 | */ |
| 1131 | int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, |
| 1132 | struct ext4_ext_path *path, |
| 1133 | struct ext4_extent *newext) |
| 1134 | { |
| 1135 | struct ext4_extent_header * eh; |
| 1136 | struct ext4_extent *ex, *fex; |
| 1137 | struct ext4_extent *nearex; /* nearest extent */ |
| 1138 | struct ext4_ext_path *npath = NULL; |
| 1139 | int depth, len, err, next; |
| 1140 | |
| 1141 | BUG_ON(newext->ee_len == 0); |
| 1142 | depth = ext_depth(inode); |
| 1143 | ex = path[depth].p_ext; |
| 1144 | BUG_ON(path[depth].p_hdr == NULL); |
| 1145 | |
| 1146 | /* try to insert block into found extent and return */ |
| 1147 | if (ex && ext4_can_extents_be_merged(inode, ex, newext)) { |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1148 | ext_debug("append %d block to %d:%d (from "E3FSBLK")\n", |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1149 | le16_to_cpu(newext->ee_len), |
| 1150 | le32_to_cpu(ex->ee_block), |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1151 | le16_to_cpu(ex->ee_len), ext_pblock(ex)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1152 | if ((err = ext4_ext_get_access(handle, inode, path + depth))) |
| 1153 | return err; |
| 1154 | ex->ee_len = cpu_to_le16(le16_to_cpu(ex->ee_len) |
| 1155 | + le16_to_cpu(newext->ee_len)); |
| 1156 | eh = path[depth].p_hdr; |
| 1157 | nearex = ex; |
| 1158 | goto merge; |
| 1159 | } |
| 1160 | |
| 1161 | repeat: |
| 1162 | depth = ext_depth(inode); |
| 1163 | eh = path[depth].p_hdr; |
| 1164 | if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) |
| 1165 | goto has_space; |
| 1166 | |
| 1167 | /* probably next leaf has space for us? */ |
| 1168 | fex = EXT_LAST_EXTENT(eh); |
| 1169 | next = ext4_ext_next_leaf_block(inode, path); |
| 1170 | if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block) |
| 1171 | && next != EXT_MAX_BLOCK) { |
| 1172 | ext_debug("next leaf block - %d\n", next); |
| 1173 | BUG_ON(npath != NULL); |
| 1174 | npath = ext4_ext_find_extent(inode, next, NULL); |
| 1175 | if (IS_ERR(npath)) |
| 1176 | return PTR_ERR(npath); |
| 1177 | BUG_ON(npath->p_depth != path->p_depth); |
| 1178 | eh = npath[depth].p_hdr; |
| 1179 | if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { |
| 1180 | ext_debug("next leaf isnt full(%d)\n", |
| 1181 | le16_to_cpu(eh->eh_entries)); |
| 1182 | path = npath; |
| 1183 | goto repeat; |
| 1184 | } |
| 1185 | ext_debug("next leaf has no free space(%d,%d)\n", |
| 1186 | le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); |
| 1187 | } |
| 1188 | |
| 1189 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1190 | * There is no free space in the found leaf. |
| 1191 | * We're gonna add a new leaf in the tree. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1192 | */ |
| 1193 | err = ext4_ext_create_new_leaf(handle, inode, path, newext); |
| 1194 | if (err) |
| 1195 | goto cleanup; |
| 1196 | depth = ext_depth(inode); |
| 1197 | eh = path[depth].p_hdr; |
| 1198 | |
| 1199 | has_space: |
| 1200 | nearex = path[depth].p_ext; |
| 1201 | |
| 1202 | if ((err = ext4_ext_get_access(handle, inode, path + depth))) |
| 1203 | goto cleanup; |
| 1204 | |
| 1205 | if (!nearex) { |
| 1206 | /* there is no extent in this leaf, create first one */ |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1207 | ext_debug("first extent in the leaf: %d:"E3FSBLK":%d\n", |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1208 | le32_to_cpu(newext->ee_block), |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1209 | ext_pblock(newext), |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1210 | le16_to_cpu(newext->ee_len)); |
| 1211 | path[depth].p_ext = EXT_FIRST_EXTENT(eh); |
| 1212 | } else if (le32_to_cpu(newext->ee_block) |
| 1213 | > le32_to_cpu(nearex->ee_block)) { |
| 1214 | /* BUG_ON(newext->ee_block == nearex->ee_block); */ |
| 1215 | if (nearex != EXT_LAST_EXTENT(eh)) { |
| 1216 | len = EXT_MAX_EXTENT(eh) - nearex; |
| 1217 | len = (len - 1) * sizeof(struct ext4_extent); |
| 1218 | len = len < 0 ? 0 : len; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1219 | ext_debug("insert %d:"E3FSBLK":%d after: nearest 0x%p, " |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1220 | "move %d from 0x%p to 0x%p\n", |
| 1221 | le32_to_cpu(newext->ee_block), |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1222 | ext_pblock(newext), |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1223 | le16_to_cpu(newext->ee_len), |
| 1224 | nearex, len, nearex + 1, nearex + 2); |
| 1225 | memmove(nearex + 2, nearex + 1, len); |
| 1226 | } |
| 1227 | path[depth].p_ext = nearex + 1; |
| 1228 | } else { |
| 1229 | BUG_ON(newext->ee_block == nearex->ee_block); |
| 1230 | len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent); |
| 1231 | len = len < 0 ? 0 : len; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1232 | ext_debug("insert %d:"E3FSBLK":%d before: nearest 0x%p, " |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1233 | "move %d from 0x%p to 0x%p\n", |
| 1234 | le32_to_cpu(newext->ee_block), |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1235 | ext_pblock(newext), |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1236 | le16_to_cpu(newext->ee_len), |
| 1237 | nearex, len, nearex + 1, nearex + 2); |
| 1238 | memmove(nearex + 1, nearex, len); |
| 1239 | path[depth].p_ext = nearex; |
| 1240 | } |
| 1241 | |
| 1242 | eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)+1); |
| 1243 | nearex = path[depth].p_ext; |
| 1244 | nearex->ee_block = newext->ee_block; |
| 1245 | nearex->ee_start = newext->ee_start; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1246 | nearex->ee_start_hi = newext->ee_start_hi; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1247 | nearex->ee_len = newext->ee_len; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1248 | |
| 1249 | merge: |
| 1250 | /* try to merge extents to the right */ |
| 1251 | while (nearex < EXT_LAST_EXTENT(eh)) { |
| 1252 | if (!ext4_can_extents_be_merged(inode, nearex, nearex + 1)) |
| 1253 | break; |
| 1254 | /* merge with next extent! */ |
| 1255 | nearex->ee_len = cpu_to_le16(le16_to_cpu(nearex->ee_len) |
| 1256 | + le16_to_cpu(nearex[1].ee_len)); |
| 1257 | if (nearex + 1 < EXT_LAST_EXTENT(eh)) { |
| 1258 | len = (EXT_LAST_EXTENT(eh) - nearex - 1) |
| 1259 | * sizeof(struct ext4_extent); |
| 1260 | memmove(nearex + 1, nearex + 2, len); |
| 1261 | } |
| 1262 | eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1); |
| 1263 | BUG_ON(eh->eh_entries == 0); |
| 1264 | } |
| 1265 | |
| 1266 | /* try to merge extents to the left */ |
| 1267 | |
| 1268 | /* time to correct all indexes above */ |
| 1269 | err = ext4_ext_correct_indexes(handle, inode, path); |
| 1270 | if (err) |
| 1271 | goto cleanup; |
| 1272 | |
| 1273 | err = ext4_ext_dirty(handle, inode, path + depth); |
| 1274 | |
| 1275 | cleanup: |
| 1276 | if (npath) { |
| 1277 | ext4_ext_drop_refs(npath); |
| 1278 | kfree(npath); |
| 1279 | } |
| 1280 | ext4_ext_tree_changed(inode); |
| 1281 | ext4_ext_invalidate_cache(inode); |
| 1282 | return err; |
| 1283 | } |
| 1284 | |
| 1285 | int ext4_ext_walk_space(struct inode *inode, unsigned long block, |
| 1286 | unsigned long num, ext_prepare_callback func, |
| 1287 | void *cbdata) |
| 1288 | { |
| 1289 | struct ext4_ext_path *path = NULL; |
| 1290 | struct ext4_ext_cache cbex; |
| 1291 | struct ext4_extent *ex; |
| 1292 | unsigned long next, start = 0, end = 0; |
| 1293 | unsigned long last = block + num; |
| 1294 | int depth, exists, err = 0; |
| 1295 | |
| 1296 | BUG_ON(func == NULL); |
| 1297 | BUG_ON(inode == NULL); |
| 1298 | |
| 1299 | while (block < last && block != EXT_MAX_BLOCK) { |
| 1300 | num = last - block; |
| 1301 | /* find extent for this block */ |
| 1302 | path = ext4_ext_find_extent(inode, block, path); |
| 1303 | if (IS_ERR(path)) { |
| 1304 | err = PTR_ERR(path); |
| 1305 | path = NULL; |
| 1306 | break; |
| 1307 | } |
| 1308 | |
| 1309 | depth = ext_depth(inode); |
| 1310 | BUG_ON(path[depth].p_hdr == NULL); |
| 1311 | ex = path[depth].p_ext; |
| 1312 | next = ext4_ext_next_allocated_block(path); |
| 1313 | |
| 1314 | exists = 0; |
| 1315 | if (!ex) { |
| 1316 | /* there is no extent yet, so try to allocate |
| 1317 | * all requested space */ |
| 1318 | start = block; |
| 1319 | end = block + num; |
| 1320 | } else if (le32_to_cpu(ex->ee_block) > block) { |
| 1321 | /* need to allocate space before found extent */ |
| 1322 | start = block; |
| 1323 | end = le32_to_cpu(ex->ee_block); |
| 1324 | if (block + num < end) |
| 1325 | end = block + num; |
| 1326 | } else if (block >= |
| 1327 | le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len)) { |
| 1328 | /* need to allocate space after found extent */ |
| 1329 | start = block; |
| 1330 | end = block + num; |
| 1331 | if (end >= next) |
| 1332 | end = next; |
| 1333 | } else if (block >= le32_to_cpu(ex->ee_block)) { |
| 1334 | /* |
| 1335 | * some part of requested space is covered |
| 1336 | * by found extent |
| 1337 | */ |
| 1338 | start = block; |
| 1339 | end = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len); |
| 1340 | if (block + num < end) |
| 1341 | end = block + num; |
| 1342 | exists = 1; |
| 1343 | } else { |
| 1344 | BUG(); |
| 1345 | } |
| 1346 | BUG_ON(end <= start); |
| 1347 | |
| 1348 | if (!exists) { |
| 1349 | cbex.ec_block = start; |
| 1350 | cbex.ec_len = end - start; |
| 1351 | cbex.ec_start = 0; |
| 1352 | cbex.ec_type = EXT4_EXT_CACHE_GAP; |
| 1353 | } else { |
| 1354 | cbex.ec_block = le32_to_cpu(ex->ee_block); |
| 1355 | cbex.ec_len = le16_to_cpu(ex->ee_len); |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1356 | cbex.ec_start = ext_pblock(ex); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1357 | cbex.ec_type = EXT4_EXT_CACHE_EXTENT; |
| 1358 | } |
| 1359 | |
| 1360 | BUG_ON(cbex.ec_len == 0); |
| 1361 | err = func(inode, path, &cbex, cbdata); |
| 1362 | ext4_ext_drop_refs(path); |
| 1363 | |
| 1364 | if (err < 0) |
| 1365 | break; |
| 1366 | if (err == EXT_REPEAT) |
| 1367 | continue; |
| 1368 | else if (err == EXT_BREAK) { |
| 1369 | err = 0; |
| 1370 | break; |
| 1371 | } |
| 1372 | |
| 1373 | if (ext_depth(inode) != depth) { |
| 1374 | /* depth was changed. we have to realloc path */ |
| 1375 | kfree(path); |
| 1376 | path = NULL; |
| 1377 | } |
| 1378 | |
| 1379 | block = cbex.ec_block + cbex.ec_len; |
| 1380 | } |
| 1381 | |
| 1382 | if (path) { |
| 1383 | ext4_ext_drop_refs(path); |
| 1384 | kfree(path); |
| 1385 | } |
| 1386 | |
| 1387 | return err; |
| 1388 | } |
| 1389 | |
| 1390 | static inline void |
| 1391 | ext4_ext_put_in_cache(struct inode *inode, __u32 block, |
| 1392 | __u32 len, __u32 start, int type) |
| 1393 | { |
| 1394 | struct ext4_ext_cache *cex; |
| 1395 | BUG_ON(len == 0); |
| 1396 | cex = &EXT4_I(inode)->i_cached_extent; |
| 1397 | cex->ec_type = type; |
| 1398 | cex->ec_block = block; |
| 1399 | cex->ec_len = len; |
| 1400 | cex->ec_start = start; |
| 1401 | } |
| 1402 | |
| 1403 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1404 | * ext4_ext_put_gap_in_cache: |
| 1405 | * calculate boundaries of the gap that the requested block fits into |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1406 | * and cache this gap |
| 1407 | */ |
| 1408 | static inline void |
| 1409 | ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, |
| 1410 | unsigned long block) |
| 1411 | { |
| 1412 | int depth = ext_depth(inode); |
| 1413 | unsigned long lblock, len; |
| 1414 | struct ext4_extent *ex; |
| 1415 | |
| 1416 | ex = path[depth].p_ext; |
| 1417 | if (ex == NULL) { |
| 1418 | /* there is no extent yet, so gap is [0;-] */ |
| 1419 | lblock = 0; |
| 1420 | len = EXT_MAX_BLOCK; |
| 1421 | ext_debug("cache gap(whole file):"); |
| 1422 | } else if (block < le32_to_cpu(ex->ee_block)) { |
| 1423 | lblock = block; |
| 1424 | len = le32_to_cpu(ex->ee_block) - block; |
| 1425 | ext_debug("cache gap(before): %lu [%lu:%lu]", |
| 1426 | (unsigned long) block, |
| 1427 | (unsigned long) le32_to_cpu(ex->ee_block), |
| 1428 | (unsigned long) le16_to_cpu(ex->ee_len)); |
| 1429 | } else if (block >= le32_to_cpu(ex->ee_block) |
| 1430 | + le16_to_cpu(ex->ee_len)) { |
| 1431 | lblock = le32_to_cpu(ex->ee_block) |
| 1432 | + le16_to_cpu(ex->ee_len); |
| 1433 | len = ext4_ext_next_allocated_block(path); |
| 1434 | ext_debug("cache gap(after): [%lu:%lu] %lu", |
| 1435 | (unsigned long) le32_to_cpu(ex->ee_block), |
| 1436 | (unsigned long) le16_to_cpu(ex->ee_len), |
| 1437 | (unsigned long) block); |
| 1438 | BUG_ON(len == lblock); |
| 1439 | len = len - lblock; |
| 1440 | } else { |
| 1441 | lblock = len = 0; |
| 1442 | BUG(); |
| 1443 | } |
| 1444 | |
| 1445 | ext_debug(" -> %lu:%lu\n", (unsigned long) lblock, len); |
| 1446 | ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP); |
| 1447 | } |
| 1448 | |
| 1449 | static inline int |
| 1450 | ext4_ext_in_cache(struct inode *inode, unsigned long block, |
| 1451 | struct ext4_extent *ex) |
| 1452 | { |
| 1453 | struct ext4_ext_cache *cex; |
| 1454 | |
| 1455 | cex = &EXT4_I(inode)->i_cached_extent; |
| 1456 | |
| 1457 | /* has cache valid data? */ |
| 1458 | if (cex->ec_type == EXT4_EXT_CACHE_NO) |
| 1459 | return EXT4_EXT_CACHE_NO; |
| 1460 | |
| 1461 | BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP && |
| 1462 | cex->ec_type != EXT4_EXT_CACHE_EXTENT); |
| 1463 | if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) { |
| 1464 | ex->ee_block = cpu_to_le32(cex->ec_block); |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1465 | ext4_ext_store_pblock(ex, cex->ec_start); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1466 | ex->ee_len = cpu_to_le16(cex->ec_len); |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1467 | ext_debug("%lu cached by %lu:%lu:"E3FSBLK"\n", |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1468 | (unsigned long) block, |
| 1469 | (unsigned long) cex->ec_block, |
| 1470 | (unsigned long) cex->ec_len, |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1471 | cex->ec_start); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1472 | return cex->ec_type; |
| 1473 | } |
| 1474 | |
| 1475 | /* not in cache */ |
| 1476 | return EXT4_EXT_CACHE_NO; |
| 1477 | } |
| 1478 | |
| 1479 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1480 | * ext4_ext_rm_idx: |
| 1481 | * removes index from the index block. |
| 1482 | * It's used in truncate case only, thus all requests are for |
| 1483 | * last index in the block only. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1484 | */ |
| 1485 | int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, |
| 1486 | struct ext4_ext_path *path) |
| 1487 | { |
| 1488 | struct buffer_head *bh; |
| 1489 | int err; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1490 | ext4_fsblk_t leaf; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1491 | |
| 1492 | /* free index block */ |
| 1493 | path--; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1494 | leaf = idx_pblock(path->p_idx); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1495 | BUG_ON(path->p_hdr->eh_entries == 0); |
| 1496 | if ((err = ext4_ext_get_access(handle, inode, path))) |
| 1497 | return err; |
| 1498 | path->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path->p_hdr->eh_entries)-1); |
| 1499 | if ((err = ext4_ext_dirty(handle, inode, path))) |
| 1500 | return err; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1501 | ext_debug("index is empty, remove it, free block "E3FSBLK"\n", leaf); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1502 | bh = sb_find_get_block(inode->i_sb, leaf); |
| 1503 | ext4_forget(handle, 1, inode, bh, leaf); |
| 1504 | ext4_free_blocks(handle, inode, leaf, 1); |
| 1505 | return err; |
| 1506 | } |
| 1507 | |
| 1508 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1509 | * ext4_ext_calc_credits_for_insert: |
| 1510 | * This routine returns max. credits that the extent tree can consume. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1511 | * It should be OK for low-performance paths like ->writepage() |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1512 | * To allow many writing processes to fit into a single transaction, |
| 1513 | * the caller should calculate credits under truncate_mutex and |
| 1514 | * pass the actual path. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1515 | */ |
| 1516 | int inline ext4_ext_calc_credits_for_insert(struct inode *inode, |
| 1517 | struct ext4_ext_path *path) |
| 1518 | { |
| 1519 | int depth, needed; |
| 1520 | |
| 1521 | if (path) { |
| 1522 | /* probably there is space in leaf? */ |
| 1523 | depth = ext_depth(inode); |
| 1524 | if (le16_to_cpu(path[depth].p_hdr->eh_entries) |
| 1525 | < le16_to_cpu(path[depth].p_hdr->eh_max)) |
| 1526 | return 1; |
| 1527 | } |
| 1528 | |
| 1529 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1530 | * given 32-bit logical block (4294967296 blocks), max. tree |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1531 | * can be 4 levels in depth -- 4 * 340^4 == 53453440000. |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1532 | * Let's also add one more level for imbalance. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1533 | */ |
| 1534 | depth = 5; |
| 1535 | |
| 1536 | /* allocation of new data block(s) */ |
| 1537 | needed = 2; |
| 1538 | |
| 1539 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1540 | * tree can be full, so it would need to grow in depth: |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1541 | * allocation + old root + new root |
| 1542 | */ |
| 1543 | needed += 2 + 1 + 1; |
| 1544 | |
| 1545 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1546 | * Index split can happen, we would need: |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1547 | * allocate intermediate indexes (bitmap + group) |
| 1548 | * + change two blocks at each level, but root (already included) |
| 1549 | */ |
| 1550 | needed = (depth * 2) + (depth * 2); |
| 1551 | |
| 1552 | /* any allocation modifies superblock */ |
| 1553 | needed += 1; |
| 1554 | |
| 1555 | return needed; |
| 1556 | } |
| 1557 | |
| 1558 | static int ext4_remove_blocks(handle_t *handle, struct inode *inode, |
| 1559 | struct ext4_extent *ex, |
| 1560 | unsigned long from, unsigned long to) |
| 1561 | { |
| 1562 | struct buffer_head *bh; |
| 1563 | int i; |
| 1564 | |
| 1565 | #ifdef EXTENTS_STATS |
| 1566 | { |
| 1567 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| 1568 | unsigned short ee_len = le16_to_cpu(ex->ee_len); |
| 1569 | spin_lock(&sbi->s_ext_stats_lock); |
| 1570 | sbi->s_ext_blocks += ee_len; |
| 1571 | sbi->s_ext_extents++; |
| 1572 | if (ee_len < sbi->s_ext_min) |
| 1573 | sbi->s_ext_min = ee_len; |
| 1574 | if (ee_len > sbi->s_ext_max) |
| 1575 | sbi->s_ext_max = ee_len; |
| 1576 | if (ext_depth(inode) > sbi->s_depth_max) |
| 1577 | sbi->s_depth_max = ext_depth(inode); |
| 1578 | spin_unlock(&sbi->s_ext_stats_lock); |
| 1579 | } |
| 1580 | #endif |
| 1581 | if (from >= le32_to_cpu(ex->ee_block) |
| 1582 | && to == le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) { |
| 1583 | /* tail removal */ |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1584 | unsigned long num; |
| 1585 | ext4_fsblk_t start; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1586 | num = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - from; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1587 | start = ext_pblock(ex) + le16_to_cpu(ex->ee_len) - num; |
| 1588 | ext_debug("free last %lu blocks starting "E3FSBLK"\n", num, start); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1589 | for (i = 0; i < num; i++) { |
| 1590 | bh = sb_find_get_block(inode->i_sb, start + i); |
| 1591 | ext4_forget(handle, 0, inode, bh, start + i); |
| 1592 | } |
| 1593 | ext4_free_blocks(handle, inode, start, num); |
| 1594 | } else if (from == le32_to_cpu(ex->ee_block) |
| 1595 | && to <= le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) { |
| 1596 | printk("strange request: removal %lu-%lu from %u:%u\n", |
| 1597 | from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len)); |
| 1598 | } else { |
| 1599 | printk("strange request: removal(2) %lu-%lu from %u:%u\n", |
| 1600 | from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len)); |
| 1601 | } |
| 1602 | return 0; |
| 1603 | } |
| 1604 | |
| 1605 | static int |
| 1606 | ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, |
| 1607 | struct ext4_ext_path *path, unsigned long start) |
| 1608 | { |
| 1609 | int err = 0, correct_index = 0; |
| 1610 | int depth = ext_depth(inode), credits; |
| 1611 | struct ext4_extent_header *eh; |
| 1612 | unsigned a, b, block, num; |
| 1613 | unsigned long ex_ee_block; |
| 1614 | unsigned short ex_ee_len; |
| 1615 | struct ext4_extent *ex; |
| 1616 | |
| 1617 | ext_debug("truncate since %lu in leaf\n", start); |
| 1618 | if (!path[depth].p_hdr) |
| 1619 | path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); |
| 1620 | eh = path[depth].p_hdr; |
| 1621 | BUG_ON(eh == NULL); |
| 1622 | BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); |
| 1623 | BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); |
| 1624 | |
| 1625 | /* find where to start removing */ |
| 1626 | ex = EXT_LAST_EXTENT(eh); |
| 1627 | |
| 1628 | ex_ee_block = le32_to_cpu(ex->ee_block); |
| 1629 | ex_ee_len = le16_to_cpu(ex->ee_len); |
| 1630 | |
| 1631 | while (ex >= EXT_FIRST_EXTENT(eh) && |
| 1632 | ex_ee_block + ex_ee_len > start) { |
| 1633 | ext_debug("remove ext %lu:%u\n", ex_ee_block, ex_ee_len); |
| 1634 | path[depth].p_ext = ex; |
| 1635 | |
| 1636 | a = ex_ee_block > start ? ex_ee_block : start; |
| 1637 | b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ? |
| 1638 | ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK; |
| 1639 | |
| 1640 | ext_debug(" border %u:%u\n", a, b); |
| 1641 | |
| 1642 | if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { |
| 1643 | block = 0; |
| 1644 | num = 0; |
| 1645 | BUG(); |
| 1646 | } else if (a != ex_ee_block) { |
| 1647 | /* remove tail of the extent */ |
| 1648 | block = ex_ee_block; |
| 1649 | num = a - block; |
| 1650 | } else if (b != ex_ee_block + ex_ee_len - 1) { |
| 1651 | /* remove head of the extent */ |
| 1652 | block = a; |
| 1653 | num = b - a; |
| 1654 | /* there is no "make a hole" API yet */ |
| 1655 | BUG(); |
| 1656 | } else { |
| 1657 | /* remove whole extent: excellent! */ |
| 1658 | block = ex_ee_block; |
| 1659 | num = 0; |
| 1660 | BUG_ON(a != ex_ee_block); |
| 1661 | BUG_ON(b != ex_ee_block + ex_ee_len - 1); |
| 1662 | } |
| 1663 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1664 | /* at present, extent can't cross block group: */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1665 | /* leaf + bitmap + group desc + sb + inode */ |
| 1666 | credits = 5; |
| 1667 | if (ex == EXT_FIRST_EXTENT(eh)) { |
| 1668 | correct_index = 1; |
| 1669 | credits += (ext_depth(inode)) + 1; |
| 1670 | } |
| 1671 | #ifdef CONFIG_QUOTA |
| 1672 | credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); |
| 1673 | #endif |
| 1674 | |
| 1675 | handle = ext4_ext_journal_restart(handle, credits); |
| 1676 | if (IS_ERR(handle)) { |
| 1677 | err = PTR_ERR(handle); |
| 1678 | goto out; |
| 1679 | } |
| 1680 | |
| 1681 | err = ext4_ext_get_access(handle, inode, path + depth); |
| 1682 | if (err) |
| 1683 | goto out; |
| 1684 | |
| 1685 | err = ext4_remove_blocks(handle, inode, ex, a, b); |
| 1686 | if (err) |
| 1687 | goto out; |
| 1688 | |
| 1689 | if (num == 0) { |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1690 | /* this extent is removed; mark slot entirely unused */ |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1691 | ext4_ext_store_pblock(ex, 0); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1692 | eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1); |
| 1693 | } |
| 1694 | |
| 1695 | ex->ee_block = cpu_to_le32(block); |
| 1696 | ex->ee_len = cpu_to_le16(num); |
| 1697 | |
| 1698 | err = ext4_ext_dirty(handle, inode, path + depth); |
| 1699 | if (err) |
| 1700 | goto out; |
| 1701 | |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1702 | ext_debug("new extent: %u:%u:"E3FSBLK"\n", block, num, |
| 1703 | ext_pblock(ex)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1704 | ex--; |
| 1705 | ex_ee_block = le32_to_cpu(ex->ee_block); |
| 1706 | ex_ee_len = le16_to_cpu(ex->ee_len); |
| 1707 | } |
| 1708 | |
| 1709 | if (correct_index && eh->eh_entries) |
| 1710 | err = ext4_ext_correct_indexes(handle, inode, path); |
| 1711 | |
| 1712 | /* if this leaf is free, then we should |
| 1713 | * remove it from index block above */ |
| 1714 | if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) |
| 1715 | err = ext4_ext_rm_idx(handle, inode, path + depth); |
| 1716 | |
| 1717 | out: |
| 1718 | return err; |
| 1719 | } |
| 1720 | |
| 1721 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1722 | * ext4_ext_more_to_rm: |
| 1723 | * returns 1 if current index has to be freed (even partial) |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1724 | */ |
| 1725 | static int inline |
| 1726 | ext4_ext_more_to_rm(struct ext4_ext_path *path) |
| 1727 | { |
| 1728 | BUG_ON(path->p_idx == NULL); |
| 1729 | |
| 1730 | if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) |
| 1731 | return 0; |
| 1732 | |
| 1733 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1734 | * if truncate on deeper level happened, it wasn't partial, |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1735 | * so we have to consider current index for truncation |
| 1736 | */ |
| 1737 | if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) |
| 1738 | return 0; |
| 1739 | return 1; |
| 1740 | } |
| 1741 | |
| 1742 | int ext4_ext_remove_space(struct inode *inode, unsigned long start) |
| 1743 | { |
| 1744 | struct super_block *sb = inode->i_sb; |
| 1745 | int depth = ext_depth(inode); |
| 1746 | struct ext4_ext_path *path; |
| 1747 | handle_t *handle; |
| 1748 | int i = 0, err = 0; |
| 1749 | |
| 1750 | ext_debug("truncate since %lu\n", start); |
| 1751 | |
| 1752 | /* probably first extent we're gonna free will be last in block */ |
| 1753 | handle = ext4_journal_start(inode, depth + 1); |
| 1754 | if (IS_ERR(handle)) |
| 1755 | return PTR_ERR(handle); |
| 1756 | |
| 1757 | ext4_ext_invalidate_cache(inode); |
| 1758 | |
| 1759 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1760 | * We start scanning from right side, freeing all the blocks |
| 1761 | * after i_size and walking into the tree depth-wise. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1762 | */ |
| 1763 | path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL); |
| 1764 | if (path == NULL) { |
| 1765 | ext4_journal_stop(handle); |
| 1766 | return -ENOMEM; |
| 1767 | } |
| 1768 | memset(path, 0, sizeof(struct ext4_ext_path) * (depth + 1)); |
| 1769 | path[0].p_hdr = ext_inode_hdr(inode); |
| 1770 | if (ext4_ext_check_header(__FUNCTION__, inode, path[0].p_hdr)) { |
| 1771 | err = -EIO; |
| 1772 | goto out; |
| 1773 | } |
| 1774 | path[0].p_depth = depth; |
| 1775 | |
| 1776 | while (i >= 0 && err == 0) { |
| 1777 | if (i == depth) { |
| 1778 | /* this is leaf block */ |
| 1779 | err = ext4_ext_rm_leaf(handle, inode, path, start); |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1780 | /* root level has p_bh == NULL, brelse() eats this */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1781 | brelse(path[i].p_bh); |
| 1782 | path[i].p_bh = NULL; |
| 1783 | i--; |
| 1784 | continue; |
| 1785 | } |
| 1786 | |
| 1787 | /* this is index block */ |
| 1788 | if (!path[i].p_hdr) { |
| 1789 | ext_debug("initialize header\n"); |
| 1790 | path[i].p_hdr = ext_block_hdr(path[i].p_bh); |
| 1791 | if (ext4_ext_check_header(__FUNCTION__, inode, |
| 1792 | path[i].p_hdr)) { |
| 1793 | err = -EIO; |
| 1794 | goto out; |
| 1795 | } |
| 1796 | } |
| 1797 | |
| 1798 | BUG_ON(le16_to_cpu(path[i].p_hdr->eh_entries) |
| 1799 | > le16_to_cpu(path[i].p_hdr->eh_max)); |
| 1800 | BUG_ON(path[i].p_hdr->eh_magic != EXT4_EXT_MAGIC); |
| 1801 | |
| 1802 | if (!path[i].p_idx) { |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1803 | /* this level hasn't been touched yet */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1804 | path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); |
| 1805 | path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; |
| 1806 | ext_debug("init index ptr: hdr 0x%p, num %d\n", |
| 1807 | path[i].p_hdr, |
| 1808 | le16_to_cpu(path[i].p_hdr->eh_entries)); |
| 1809 | } else { |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1810 | /* we were already here, see at next index */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1811 | path[i].p_idx--; |
| 1812 | } |
| 1813 | |
| 1814 | ext_debug("level %d - index, first 0x%p, cur 0x%p\n", |
| 1815 | i, EXT_FIRST_INDEX(path[i].p_hdr), |
| 1816 | path[i].p_idx); |
| 1817 | if (ext4_ext_more_to_rm(path + i)) { |
| 1818 | /* go to the next level */ |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1819 | ext_debug("move to level %d (block "E3FSBLK")\n", |
| 1820 | i + 1, idx_pblock(path[i].p_idx)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1821 | memset(path + i + 1, 0, sizeof(*path)); |
| 1822 | path[i+1].p_bh = |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1823 | sb_bread(sb, idx_pblock(path[i].p_idx)); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1824 | if (!path[i+1].p_bh) { |
| 1825 | /* should we reset i_size? */ |
| 1826 | err = -EIO; |
| 1827 | break; |
| 1828 | } |
| 1829 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1830 | /* save actual number of indexes since this |
| 1831 | * number is changed at the next iteration */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1832 | path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); |
| 1833 | i++; |
| 1834 | } else { |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1835 | /* we finished processing this index, go up */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1836 | if (path[i].p_hdr->eh_entries == 0 && i > 0) { |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1837 | /* index is empty, remove it; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1838 | * handle must be already prepared by the |
| 1839 | * truncatei_leaf() */ |
| 1840 | err = ext4_ext_rm_idx(handle, inode, path + i); |
| 1841 | } |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1842 | /* root level has p_bh == NULL, brelse() eats this */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1843 | brelse(path[i].p_bh); |
| 1844 | path[i].p_bh = NULL; |
| 1845 | i--; |
| 1846 | ext_debug("return to level %d\n", i); |
| 1847 | } |
| 1848 | } |
| 1849 | |
| 1850 | /* TODO: flexible tree reduction should be here */ |
| 1851 | if (path->p_hdr->eh_entries == 0) { |
| 1852 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1853 | * truncate to zero freed all the tree, |
| 1854 | * so we need to correct eh_depth |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1855 | */ |
| 1856 | err = ext4_ext_get_access(handle, inode, path); |
| 1857 | if (err == 0) { |
| 1858 | ext_inode_hdr(inode)->eh_depth = 0; |
| 1859 | ext_inode_hdr(inode)->eh_max = |
| 1860 | cpu_to_le16(ext4_ext_space_root(inode)); |
| 1861 | err = ext4_ext_dirty(handle, inode, path); |
| 1862 | } |
| 1863 | } |
| 1864 | out: |
| 1865 | ext4_ext_tree_changed(inode); |
| 1866 | ext4_ext_drop_refs(path); |
| 1867 | kfree(path); |
| 1868 | ext4_journal_stop(handle); |
| 1869 | |
| 1870 | return err; |
| 1871 | } |
| 1872 | |
| 1873 | /* |
| 1874 | * called at mount time |
| 1875 | */ |
| 1876 | void ext4_ext_init(struct super_block *sb) |
| 1877 | { |
| 1878 | /* |
| 1879 | * possible initialization would be here |
| 1880 | */ |
| 1881 | |
| 1882 | if (test_opt(sb, EXTENTS)) { |
| 1883 | printk("EXT4-fs: file extents enabled"); |
| 1884 | #ifdef AGRESSIVE_TEST |
| 1885 | printk(", agressive tests"); |
| 1886 | #endif |
| 1887 | #ifdef CHECK_BINSEARCH |
| 1888 | printk(", check binsearch"); |
| 1889 | #endif |
| 1890 | #ifdef EXTENTS_STATS |
| 1891 | printk(", stats"); |
| 1892 | #endif |
| 1893 | printk("\n"); |
| 1894 | #ifdef EXTENTS_STATS |
| 1895 | spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); |
| 1896 | EXT4_SB(sb)->s_ext_min = 1 << 30; |
| 1897 | EXT4_SB(sb)->s_ext_max = 0; |
| 1898 | #endif |
| 1899 | } |
| 1900 | } |
| 1901 | |
| 1902 | /* |
| 1903 | * called at umount time |
| 1904 | */ |
| 1905 | void ext4_ext_release(struct super_block *sb) |
| 1906 | { |
| 1907 | if (!test_opt(sb, EXTENTS)) |
| 1908 | return; |
| 1909 | |
| 1910 | #ifdef EXTENTS_STATS |
| 1911 | if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { |
| 1912 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 1913 | printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", |
| 1914 | sbi->s_ext_blocks, sbi->s_ext_extents, |
| 1915 | sbi->s_ext_blocks / sbi->s_ext_extents); |
| 1916 | printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", |
| 1917 | sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); |
| 1918 | } |
| 1919 | #endif |
| 1920 | } |
| 1921 | |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1922 | int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, |
| 1923 | ext4_fsblk_t iblock, |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1924 | unsigned long max_blocks, struct buffer_head *bh_result, |
| 1925 | int create, int extend_disksize) |
| 1926 | { |
| 1927 | struct ext4_ext_path *path = NULL; |
| 1928 | struct ext4_extent newex, *ex; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1929 | ext4_fsblk_t goal, newblock; |
| 1930 | int err = 0, depth; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1931 | unsigned long allocated = 0; |
| 1932 | |
| 1933 | __clear_bit(BH_New, &bh_result->b_state); |
| 1934 | ext_debug("blocks %d/%lu requested for inode %u\n", (int) iblock, |
| 1935 | max_blocks, (unsigned) inode->i_ino); |
| 1936 | mutex_lock(&EXT4_I(inode)->truncate_mutex); |
| 1937 | |
| 1938 | /* check in cache */ |
| 1939 | if ((goal = ext4_ext_in_cache(inode, iblock, &newex))) { |
| 1940 | if (goal == EXT4_EXT_CACHE_GAP) { |
| 1941 | if (!create) { |
| 1942 | /* block isn't allocated yet and |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1943 | * user doesn't want to allocate it */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1944 | goto out2; |
| 1945 | } |
| 1946 | /* we should allocate requested block */ |
| 1947 | } else if (goal == EXT4_EXT_CACHE_EXTENT) { |
| 1948 | /* block is already allocated */ |
| 1949 | newblock = iblock |
| 1950 | - le32_to_cpu(newex.ee_block) |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1951 | + ext_pblock(&newex); |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1952 | /* number of remaining blocks in the extent */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1953 | allocated = le16_to_cpu(newex.ee_len) - |
| 1954 | (iblock - le32_to_cpu(newex.ee_block)); |
| 1955 | goto out; |
| 1956 | } else { |
| 1957 | BUG(); |
| 1958 | } |
| 1959 | } |
| 1960 | |
| 1961 | /* find extent for this block */ |
| 1962 | path = ext4_ext_find_extent(inode, iblock, NULL); |
| 1963 | if (IS_ERR(path)) { |
| 1964 | err = PTR_ERR(path); |
| 1965 | path = NULL; |
| 1966 | goto out2; |
| 1967 | } |
| 1968 | |
| 1969 | depth = ext_depth(inode); |
| 1970 | |
| 1971 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1972 | * consistent leaf must not be empty; |
| 1973 | * this situation is possible, though, _during_ tree modification; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1974 | * this is why assert can't be put in ext4_ext_find_extent() |
| 1975 | */ |
| 1976 | BUG_ON(path[depth].p_ext == NULL && depth != 0); |
| 1977 | |
| 1978 | if ((ex = path[depth].p_ext)) { |
| 1979 | unsigned long ee_block = le32_to_cpu(ex->ee_block); |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1980 | ext4_fsblk_t ee_start = ext_pblock(ex); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1981 | unsigned short ee_len = le16_to_cpu(ex->ee_len); |
Suparna Bhattacharya | 471d401 | 2006-10-11 01:21:06 -0700 | [diff] [blame] | 1982 | |
| 1983 | /* |
| 1984 | * Allow future support for preallocated extents to be added |
| 1985 | * as an RO_COMPAT feature: |
| 1986 | * Uninitialized extents are treated as holes, except that |
| 1987 | * we avoid (fail) allocating new blocks during a write. |
| 1988 | */ |
| 1989 | if (ee_len > EXT_MAX_LEN) |
| 1990 | goto out2; |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1991 | /* if found extent covers block, simply return it */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1992 | if (iblock >= ee_block && iblock < ee_block + ee_len) { |
| 1993 | newblock = iblock - ee_block + ee_start; |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 1994 | /* number of remaining blocks in the extent */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1995 | allocated = ee_len - (iblock - ee_block); |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 1996 | ext_debug("%d fit into %lu:%d -> "E3FSBLK"\n", (int) iblock, |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 1997 | ee_block, ee_len, newblock); |
| 1998 | ext4_ext_put_in_cache(inode, ee_block, ee_len, |
| 1999 | ee_start, EXT4_EXT_CACHE_EXTENT); |
| 2000 | goto out; |
| 2001 | } |
| 2002 | } |
| 2003 | |
| 2004 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 2005 | * requested block isn't allocated yet; |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2006 | * we couldn't try to create block if create flag is zero |
| 2007 | */ |
| 2008 | if (!create) { |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 2009 | /* put just found gap into cache to speed up |
| 2010 | * subsequent requests */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2011 | ext4_ext_put_gap_in_cache(inode, path, iblock); |
| 2012 | goto out2; |
| 2013 | } |
| 2014 | /* |
| 2015 | * Okay, we need to do block allocation. Lazily initialize the block |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 2016 | * allocation info here if necessary. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2017 | */ |
| 2018 | if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info)) |
| 2019 | ext4_init_block_alloc_info(inode); |
| 2020 | |
| 2021 | /* allocate new block */ |
| 2022 | goal = ext4_ext_find_goal(inode, path, iblock); |
| 2023 | allocated = max_blocks; |
| 2024 | newblock = ext4_new_blocks(handle, inode, goal, &allocated, &err); |
| 2025 | if (!newblock) |
| 2026 | goto out2; |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 2027 | ext_debug("allocate new block: goal "E3FSBLK", found "E3FSBLK"/%lu\n", |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2028 | goal, newblock, allocated); |
| 2029 | |
| 2030 | /* try to insert new extent into found leaf and return */ |
| 2031 | newex.ee_block = cpu_to_le32(iblock); |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 2032 | ext4_ext_store_pblock(&newex, newblock); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2033 | newex.ee_len = cpu_to_le16(allocated); |
| 2034 | err = ext4_ext_insert_extent(handle, inode, path, &newex); |
| 2035 | if (err) |
| 2036 | goto out2; |
| 2037 | |
| 2038 | if (extend_disksize && inode->i_size > EXT4_I(inode)->i_disksize) |
| 2039 | EXT4_I(inode)->i_disksize = inode->i_size; |
| 2040 | |
| 2041 | /* previous routine could use block we allocated */ |
Alex Tomas | f65e6fb | 2006-10-11 01:21:05 -0700 | [diff] [blame] | 2042 | newblock = ext_pblock(&newex); |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2043 | __set_bit(BH_New, &bh_result->b_state); |
| 2044 | |
| 2045 | ext4_ext_put_in_cache(inode, iblock, allocated, newblock, |
| 2046 | EXT4_EXT_CACHE_EXTENT); |
| 2047 | out: |
| 2048 | if (allocated > max_blocks) |
| 2049 | allocated = max_blocks; |
| 2050 | ext4_ext_show_leaf(inode, path); |
| 2051 | __set_bit(BH_Mapped, &bh_result->b_state); |
| 2052 | bh_result->b_bdev = inode->i_sb->s_bdev; |
| 2053 | bh_result->b_blocknr = newblock; |
| 2054 | out2: |
| 2055 | if (path) { |
| 2056 | ext4_ext_drop_refs(path); |
| 2057 | kfree(path); |
| 2058 | } |
| 2059 | mutex_unlock(&EXT4_I(inode)->truncate_mutex); |
| 2060 | |
| 2061 | return err ? err : allocated; |
| 2062 | } |
| 2063 | |
| 2064 | void ext4_ext_truncate(struct inode * inode, struct page *page) |
| 2065 | { |
| 2066 | struct address_space *mapping = inode->i_mapping; |
| 2067 | struct super_block *sb = inode->i_sb; |
| 2068 | unsigned long last_block; |
| 2069 | handle_t *handle; |
| 2070 | int err = 0; |
| 2071 | |
| 2072 | /* |
| 2073 | * probably first extent we're gonna free will be last in block |
| 2074 | */ |
| 2075 | err = ext4_writepage_trans_blocks(inode) + 3; |
| 2076 | handle = ext4_journal_start(inode, err); |
| 2077 | if (IS_ERR(handle)) { |
| 2078 | if (page) { |
| 2079 | clear_highpage(page); |
| 2080 | flush_dcache_page(page); |
| 2081 | unlock_page(page); |
| 2082 | page_cache_release(page); |
| 2083 | } |
| 2084 | return; |
| 2085 | } |
| 2086 | |
| 2087 | if (page) |
| 2088 | ext4_block_truncate_page(handle, page, mapping, inode->i_size); |
| 2089 | |
| 2090 | mutex_lock(&EXT4_I(inode)->truncate_mutex); |
| 2091 | ext4_ext_invalidate_cache(inode); |
| 2092 | |
| 2093 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 2094 | * TODO: optimization is possible here. |
| 2095 | * Probably we need not scan at all, |
| 2096 | * because page truncation is enough. |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2097 | */ |
| 2098 | if (ext4_orphan_add(handle, inode)) |
| 2099 | goto out_stop; |
| 2100 | |
| 2101 | /* we have to know where to truncate from in crash case */ |
| 2102 | EXT4_I(inode)->i_disksize = inode->i_size; |
| 2103 | ext4_mark_inode_dirty(handle, inode); |
| 2104 | |
| 2105 | last_block = (inode->i_size + sb->s_blocksize - 1) |
| 2106 | >> EXT4_BLOCK_SIZE_BITS(sb); |
| 2107 | err = ext4_ext_remove_space(inode, last_block); |
| 2108 | |
| 2109 | /* In a multi-transaction truncate, we only make the final |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 2110 | * transaction synchronous. */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2111 | if (IS_SYNC(inode)) |
| 2112 | handle->h_sync = 1; |
| 2113 | |
| 2114 | out_stop: |
| 2115 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 2116 | * If this was a simple ftruncate() and the file will remain alive, |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2117 | * then we need to clear up the orphan record which we created above. |
| 2118 | * However, if this was a real unlink then we were called by |
| 2119 | * ext4_delete_inode(), and we allow that function to clean up the |
| 2120 | * orphan info for us. |
| 2121 | */ |
| 2122 | if (inode->i_nlink) |
| 2123 | ext4_orphan_del(handle, inode); |
| 2124 | |
| 2125 | mutex_unlock(&EXT4_I(inode)->truncate_mutex); |
| 2126 | ext4_journal_stop(handle); |
| 2127 | } |
| 2128 | |
| 2129 | /* |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 2130 | * ext4_ext_writepage_trans_blocks: |
| 2131 | * calculate max number of blocks we could modify |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2132 | * in order to allocate new block for an inode |
| 2133 | */ |
| 2134 | int ext4_ext_writepage_trans_blocks(struct inode *inode, int num) |
| 2135 | { |
| 2136 | int needed; |
| 2137 | |
| 2138 | needed = ext4_ext_calc_credits_for_insert(inode, NULL); |
| 2139 | |
Randy Dunlap | d0d856e | 2006-10-11 01:21:07 -0700 | [diff] [blame^] | 2140 | /* caller wants to allocate num blocks, but note it includes sb */ |
Alex Tomas | a86c618 | 2006-10-11 01:21:03 -0700 | [diff] [blame] | 2141 | needed = needed * num - (num - 1); |
| 2142 | |
| 2143 | #ifdef CONFIG_QUOTA |
| 2144 | needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); |
| 2145 | #endif |
| 2146 | |
| 2147 | return needed; |
| 2148 | } |
| 2149 | |
| 2150 | EXPORT_SYMBOL(ext4_mark_inode_dirty); |
| 2151 | EXPORT_SYMBOL(ext4_ext_invalidate_cache); |
| 2152 | EXPORT_SYMBOL(ext4_ext_insert_extent); |
| 2153 | EXPORT_SYMBOL(ext4_ext_walk_space); |
| 2154 | EXPORT_SYMBOL(ext4_ext_find_goal); |
| 2155 | EXPORT_SYMBOL(ext4_ext_calc_credits_for_insert); |
| 2156 | |