1 /* 2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. 4 * 5 * This copyrighted material is made available to anyone wishing to use, 6 * modify, copy, or redistribute it subject to the terms and conditions 7 * of the GNU General Public License version 2. 8 */ 9 10 #include <linux/spinlock.h> 11 #include <linux/completion.h> 12 #include <linux/buffer_head.h> 13 #include <linux/gfs2_ondisk.h> 14 #include <linux/crc32.h> 15 16 #include "gfs2.h" 17 #include "incore.h" 18 #include "bmap.h" 19 #include "glock.h" 20 #include "inode.h" 21 #include "meta_io.h" 22 #include "quota.h" 23 #include "rgrp.h" 24 #include "trans.h" 25 #include "dir.h" 26 #include "util.h" 27 #include "trace_gfs2.h" 28 29 /* This doesn't need to be that large as max 64 bit pointers in a 4k 30 * block is 512, so __u16 is fine for that. It saves stack space to 31 * keep it small. 32 */ 33 struct metapath { 34 struct buffer_head *mp_bh[GFS2_MAX_META_HEIGHT]; 35 __u16 mp_list[GFS2_MAX_META_HEIGHT]; 36 }; 37 38 typedef int (*block_call_t) (struct gfs2_inode *ip, struct buffer_head *dibh, 39 struct buffer_head *bh, __be64 *top, 40 __be64 *bottom, unsigned int height, 41 void *data); 42 43 struct strip_mine { 44 int sm_first; 45 unsigned int sm_height; 46 }; 47 48 /** 49 * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page 50 * @ip: the inode 51 * @dibh: the dinode buffer 52 * @block: the block number that was allocated 53 * @private: any locked page held by the caller process 54 * 55 * Returns: errno 56 */ 57 58 static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh, 59 u64 block, struct page *page) 60 { 61 struct inode *inode = &ip->i_inode; 62 struct buffer_head *bh; 63 int release = 0; 64 65 if (!page || page->index) { 66 page = grab_cache_page(inode->i_mapping, 0); 67 if (!page) 68 return -ENOMEM; 69 release = 1; 70 } 71 72 if (!PageUptodate(page)) { 73 void *kaddr = kmap(page); 74 u64 dsize = i_size_read(inode); 75 76 if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode))) 77 dsize = dibh->b_size - sizeof(struct gfs2_dinode); 78 79 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize); 80 memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize); 81 kunmap(page); 82 83 SetPageUptodate(page); 84 } 85 86 if (!page_has_buffers(page)) 87 create_empty_buffers(page, 1 << inode->i_blkbits, 88 (1 << BH_Uptodate)); 89 90 bh = page_buffers(page); 91 92 if (!buffer_mapped(bh)) 93 map_bh(bh, inode->i_sb, block); 94 95 set_buffer_uptodate(bh); 96 if (!gfs2_is_jdata(ip)) 97 mark_buffer_dirty(bh); 98 if (!gfs2_is_writeback(ip)) 99 gfs2_trans_add_bh(ip->i_gl, bh, 0); 100 101 if (release) { 102 unlock_page(page); 103 page_cache_release(page); 104 } 105 106 return 0; 107 } 108 109 /** 110 * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big 111 * @ip: The GFS2 inode to unstuff 112 * @unstuffer: the routine that handles unstuffing a non-zero length file 113 * @private: private data for the unstuffer 114 * 115 * This routine unstuffs a dinode and returns it to a "normal" state such 116 * that the height can be grown in the traditional way. 117 * 118 * Returns: errno 119 */ 120 121 int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page) 122 { 123 struct buffer_head *bh, *dibh; 124 struct gfs2_dinode *di; 125 u64 block = 0; 126 int isdir = gfs2_is_dir(ip); 127 int error; 128 129 down_write(&ip->i_rw_mutex); 130 131 error = gfs2_meta_inode_buffer(ip, &dibh); 132 if (error) 133 goto out; 134 135 if (ip->i_disksize) { 136 /* Get a free block, fill it with the stuffed data, 137 and write it out to disk */ 138 139 unsigned int n = 1; 140 error = gfs2_alloc_block(ip, &block, &n); 141 if (error) 142 goto out_brelse; 143 if (isdir) { 144 gfs2_trans_add_unrevoke(GFS2_SB(&ip->i_inode), block, 1); 145 error = gfs2_dir_get_new_buffer(ip, block, &bh); 146 if (error) 147 goto out_brelse; 148 gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_meta_header), 149 dibh, sizeof(struct gfs2_dinode)); 150 brelse(bh); 151 } else { 152 error = gfs2_unstuffer_page(ip, dibh, block, page); 153 if (error) 154 goto out_brelse; 155 } 156 } 157 158 /* Set up the pointer to the new block */ 159 160 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 161 di = (struct gfs2_dinode *)dibh->b_data; 162 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); 163 164 if (ip->i_disksize) { 165 *(__be64 *)(di + 1) = cpu_to_be64(block); 166 gfs2_add_inode_blocks(&ip->i_inode, 1); 167 di->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode)); 168 } 169 170 ip->i_height = 1; 171 di->di_height = cpu_to_be16(1); 172 173 out_brelse: 174 brelse(dibh); 175 out: 176 up_write(&ip->i_rw_mutex); 177 return error; 178 } 179 180 181 /** 182 * find_metapath - Find path through the metadata tree 183 * @sdp: The superblock 184 * @mp: The metapath to return the result in 185 * @block: The disk block to look up 186 * @height: The pre-calculated height of the metadata tree 187 * 188 * This routine returns a struct metapath structure that defines a path 189 * through the metadata of inode "ip" to get to block "block". 190 * 191 * Example: 192 * Given: "ip" is a height 3 file, "offset" is 101342453, and this is a 193 * filesystem with a blocksize of 4096. 194 * 195 * find_metapath() would return a struct metapath structure set to: 196 * mp_offset = 101342453, mp_height = 3, mp_list[0] = 0, mp_list[1] = 48, 197 * and mp_list[2] = 165. 198 * 199 * That means that in order to get to the block containing the byte at 200 * offset 101342453, we would load the indirect block pointed to by pointer 201 * 0 in the dinode. We would then load the indirect block pointed to by 202 * pointer 48 in that indirect block. We would then load the data block 203 * pointed to by pointer 165 in that indirect block. 204 * 205 * ---------------------------------------- 206 * | Dinode | | 207 * | | 4| 208 * | |0 1 2 3 4 5 9| 209 * | | 6| 210 * ---------------------------------------- 211 * | 212 * | 213 * V 214 * ---------------------------------------- 215 * | Indirect Block | 216 * | 5| 217 * | 4 4 4 4 4 5 5 1| 218 * |0 5 6 7 8 9 0 1 2| 219 * ---------------------------------------- 220 * | 221 * | 222 * V 223 * ---------------------------------------- 224 * | Indirect Block | 225 * | 1 1 1 1 1 5| 226 * | 6 6 6 6 6 1| 227 * |0 3 4 5 6 7 2| 228 * ---------------------------------------- 229 * | 230 * | 231 * V 232 * ---------------------------------------- 233 * | Data block containing offset | 234 * | 101342453 | 235 * | | 236 * | | 237 * ---------------------------------------- 238 * 239 */ 240 241 static void find_metapath(const struct gfs2_sbd *sdp, u64 block, 242 struct metapath *mp, unsigned int height) 243 { 244 unsigned int i; 245 246 for (i = height; i--;) 247 mp->mp_list[i] = do_div(block, sdp->sd_inptrs); 248 249 } 250 251 static inline unsigned int metapath_branch_start(const struct metapath *mp) 252 { 253 if (mp->mp_list[0] == 0) 254 return 2; 255 return 1; 256 } 257 258 /** 259 * metapointer - Return pointer to start of metadata in a buffer 260 * @height: The metadata height (0 = dinode) 261 * @mp: The metapath 262 * 263 * Return a pointer to the block number of the next height of the metadata 264 * tree given a buffer containing the pointer to the current height of the 265 * metadata tree. 266 */ 267 268 static inline __be64 *metapointer(unsigned int height, const struct metapath *mp) 269 { 270 struct buffer_head *bh = mp->mp_bh[height]; 271 unsigned int head_size = (height > 0) ? 272 sizeof(struct gfs2_meta_header) : sizeof(struct gfs2_dinode); 273 return ((__be64 *)(bh->b_data + head_size)) + mp->mp_list[height]; 274 } 275 276 /** 277 * lookup_metapath - Walk the metadata tree to a specific point 278 * @ip: The inode 279 * @mp: The metapath 280 * 281 * Assumes that the inode's buffer has already been looked up and 282 * hooked onto mp->mp_bh[0] and that the metapath has been initialised 283 * by find_metapath(). 284 * 285 * If this function encounters part of the tree which has not been 286 * allocated, it returns the current height of the tree at the point 287 * at which it found the unallocated block. Blocks which are found are 288 * added to the mp->mp_bh[] list. 289 * 290 * Returns: error or height of metadata tree 291 */ 292 293 static int lookup_metapath(struct gfs2_inode *ip, struct metapath *mp) 294 { 295 unsigned int end_of_metadata = ip->i_height - 1; 296 unsigned int x; 297 __be64 *ptr; 298 u64 dblock; 299 int ret; 300 301 for (x = 0; x < end_of_metadata; x++) { 302 ptr = metapointer(x, mp); 303 dblock = be64_to_cpu(*ptr); 304 if (!dblock) 305 return x + 1; 306 307 ret = gfs2_meta_indirect_buffer(ip, x+1, dblock, 0, &mp->mp_bh[x+1]); 308 if (ret) 309 return ret; 310 } 311 312 return ip->i_height; 313 } 314 315 static inline void release_metapath(struct metapath *mp) 316 { 317 int i; 318 319 for (i = 0; i < GFS2_MAX_META_HEIGHT; i++) { 320 if (mp->mp_bh[i] == NULL) 321 break; 322 brelse(mp->mp_bh[i]); 323 } 324 } 325 326 /** 327 * gfs2_extent_length - Returns length of an extent of blocks 328 * @start: Start of the buffer 329 * @len: Length of the buffer in bytes 330 * @ptr: Current position in the buffer 331 * @limit: Max extent length to return (0 = unlimited) 332 * @eob: Set to 1 if we hit "end of block" 333 * 334 * If the first block is zero (unallocated) it will return the number of 335 * unallocated blocks in the extent, otherwise it will return the number 336 * of contiguous blocks in the extent. 337 * 338 * Returns: The length of the extent (minimum of one block) 339 */ 340 341 static inline unsigned int gfs2_extent_length(void *start, unsigned int len, __be64 *ptr, unsigned limit, int *eob) 342 { 343 const __be64 *end = (start + len); 344 const __be64 *first = ptr; 345 u64 d = be64_to_cpu(*ptr); 346 347 *eob = 0; 348 do { 349 ptr++; 350 if (ptr >= end) 351 break; 352 if (limit && --limit == 0) 353 break; 354 if (d) 355 d++; 356 } while(be64_to_cpu(*ptr) == d); 357 if (ptr >= end) 358 *eob = 1; 359 return (ptr - first); 360 } 361 362 static inline void bmap_lock(struct gfs2_inode *ip, int create) 363 { 364 if (create) 365 down_write(&ip->i_rw_mutex); 366 else 367 down_read(&ip->i_rw_mutex); 368 } 369 370 static inline void bmap_unlock(struct gfs2_inode *ip, int create) 371 { 372 if (create) 373 up_write(&ip->i_rw_mutex); 374 else 375 up_read(&ip->i_rw_mutex); 376 } 377 378 static inline __be64 *gfs2_indirect_init(struct metapath *mp, 379 struct gfs2_glock *gl, unsigned int i, 380 unsigned offset, u64 bn) 381 { 382 __be64 *ptr = (__be64 *)(mp->mp_bh[i - 1]->b_data + 383 ((i > 1) ? sizeof(struct gfs2_meta_header) : 384 sizeof(struct gfs2_dinode))); 385 BUG_ON(i < 1); 386 BUG_ON(mp->mp_bh[i] != NULL); 387 mp->mp_bh[i] = gfs2_meta_new(gl, bn); 388 gfs2_trans_add_bh(gl, mp->mp_bh[i], 1); 389 gfs2_metatype_set(mp->mp_bh[i], GFS2_METATYPE_IN, GFS2_FORMAT_IN); 390 gfs2_buffer_clear_tail(mp->mp_bh[i], sizeof(struct gfs2_meta_header)); 391 ptr += offset; 392 *ptr = cpu_to_be64(bn); 393 return ptr; 394 } 395 396 enum alloc_state { 397 ALLOC_DATA = 0, 398 ALLOC_GROW_DEPTH = 1, 399 ALLOC_GROW_HEIGHT = 2, 400 /* ALLOC_UNSTUFF = 3, TBD and rather complicated */ 401 }; 402 403 /** 404 * gfs2_bmap_alloc - Build a metadata tree of the requested height 405 * @inode: The GFS2 inode 406 * @lblock: The logical starting block of the extent 407 * @bh_map: This is used to return the mapping details 408 * @mp: The metapath 409 * @sheight: The starting height (i.e. whats already mapped) 410 * @height: The height to build to 411 * @maxlen: The max number of data blocks to alloc 412 * 413 * In this routine we may have to alloc: 414 * i) Indirect blocks to grow the metadata tree height 415 * ii) Indirect blocks to fill in lower part of the metadata tree 416 * iii) Data blocks 417 * 418 * The function is in two parts. The first part works out the total 419 * number of blocks which we need. The second part does the actual 420 * allocation asking for an extent at a time (if enough contiguous free 421 * blocks are available, there will only be one request per bmap call) 422 * and uses the state machine to initialise the blocks in order. 423 * 424 * Returns: errno on error 425 */ 426 427 static int gfs2_bmap_alloc(struct inode *inode, const sector_t lblock, 428 struct buffer_head *bh_map, struct metapath *mp, 429 const unsigned int sheight, 430 const unsigned int height, 431 const unsigned int maxlen) 432 { 433 struct gfs2_inode *ip = GFS2_I(inode); 434 struct gfs2_sbd *sdp = GFS2_SB(inode); 435 struct buffer_head *dibh = mp->mp_bh[0]; 436 u64 bn, dblock = 0; 437 unsigned n, i, blks, alloced = 0, iblks = 0, branch_start = 0; 438 unsigned dblks = 0; 439 unsigned ptrs_per_blk; 440 const unsigned end_of_metadata = height - 1; 441 int eob = 0; 442 enum alloc_state state; 443 __be64 *ptr; 444 __be64 zero_bn = 0; 445 446 BUG_ON(sheight < 1); 447 BUG_ON(dibh == NULL); 448 449 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 450 451 if (height == sheight) { 452 struct buffer_head *bh; 453 /* Bottom indirect block exists, find unalloced extent size */ 454 ptr = metapointer(end_of_metadata, mp); 455 bh = mp->mp_bh[end_of_metadata]; 456 dblks = gfs2_extent_length(bh->b_data, bh->b_size, ptr, maxlen, 457 &eob); 458 BUG_ON(dblks < 1); 459 state = ALLOC_DATA; 460 } else { 461 /* Need to allocate indirect blocks */ 462 ptrs_per_blk = height > 1 ? sdp->sd_inptrs : sdp->sd_diptrs; 463 dblks = min(maxlen, ptrs_per_blk - mp->mp_list[end_of_metadata]); 464 if (height == ip->i_height) { 465 /* Writing into existing tree, extend tree down */ 466 iblks = height - sheight; 467 state = ALLOC_GROW_DEPTH; 468 } else { 469 /* Building up tree height */ 470 state = ALLOC_GROW_HEIGHT; 471 iblks = height - ip->i_height; 472 branch_start = metapath_branch_start(mp); 473 iblks += (height - branch_start); 474 } 475 } 476 477 /* start of the second part of the function (state machine) */ 478 479 blks = dblks + iblks; 480 i = sheight; 481 do { 482 int error; 483 n = blks - alloced; 484 error = gfs2_alloc_block(ip, &bn, &n); 485 if (error) 486 return error; 487 alloced += n; 488 if (state != ALLOC_DATA || gfs2_is_jdata(ip)) 489 gfs2_trans_add_unrevoke(sdp, bn, n); 490 switch (state) { 491 /* Growing height of tree */ 492 case ALLOC_GROW_HEIGHT: 493 if (i == 1) { 494 ptr = (__be64 *)(dibh->b_data + 495 sizeof(struct gfs2_dinode)); 496 zero_bn = *ptr; 497 } 498 for (; i - 1 < height - ip->i_height && n > 0; i++, n--) 499 gfs2_indirect_init(mp, ip->i_gl, i, 0, bn++); 500 if (i - 1 == height - ip->i_height) { 501 i--; 502 gfs2_buffer_copy_tail(mp->mp_bh[i], 503 sizeof(struct gfs2_meta_header), 504 dibh, sizeof(struct gfs2_dinode)); 505 gfs2_buffer_clear_tail(dibh, 506 sizeof(struct gfs2_dinode) + 507 sizeof(__be64)); 508 ptr = (__be64 *)(mp->mp_bh[i]->b_data + 509 sizeof(struct gfs2_meta_header)); 510 *ptr = zero_bn; 511 state = ALLOC_GROW_DEPTH; 512 for(i = branch_start; i < height; i++) { 513 if (mp->mp_bh[i] == NULL) 514 break; 515 brelse(mp->mp_bh[i]); 516 mp->mp_bh[i] = NULL; 517 } 518 i = branch_start; 519 } 520 if (n == 0) 521 break; 522 /* Branching from existing tree */ 523 case ALLOC_GROW_DEPTH: 524 if (i > 1 && i < height) 525 gfs2_trans_add_bh(ip->i_gl, mp->mp_bh[i-1], 1); 526 for (; i < height && n > 0; i++, n--) 527 gfs2_indirect_init(mp, ip->i_gl, i, 528 mp->mp_list[i-1], bn++); 529 if (i == height) 530 state = ALLOC_DATA; 531 if (n == 0) 532 break; 533 /* Tree complete, adding data blocks */ 534 case ALLOC_DATA: 535 BUG_ON(n > dblks); 536 BUG_ON(mp->mp_bh[end_of_metadata] == NULL); 537 gfs2_trans_add_bh(ip->i_gl, mp->mp_bh[end_of_metadata], 1); 538 dblks = n; 539 ptr = metapointer(end_of_metadata, mp); 540 dblock = bn; 541 while (n-- > 0) 542 *ptr++ = cpu_to_be64(bn++); 543 break; 544 } 545 } while ((state != ALLOC_DATA) || !dblock); 546 547 ip->i_height = height; 548 gfs2_add_inode_blocks(&ip->i_inode, alloced); 549 gfs2_dinode_out(ip, mp->mp_bh[0]->b_data); 550 map_bh(bh_map, inode->i_sb, dblock); 551 bh_map->b_size = dblks << inode->i_blkbits; 552 set_buffer_new(bh_map); 553 return 0; 554 } 555 556 /** 557 * gfs2_block_map - Map a block from an inode to a disk block 558 * @inode: The inode 559 * @lblock: The logical block number 560 * @bh_map: The bh to be mapped 561 * @create: True if its ok to alloc blocks to satify the request 562 * 563 * Sets buffer_mapped() if successful, sets buffer_boundary() if a 564 * read of metadata will be required before the next block can be 565 * mapped. Sets buffer_new() if new blocks were allocated. 566 * 567 * Returns: errno 568 */ 569 570 int gfs2_block_map(struct inode *inode, sector_t lblock, 571 struct buffer_head *bh_map, int create) 572 { 573 struct gfs2_inode *ip = GFS2_I(inode); 574 struct gfs2_sbd *sdp = GFS2_SB(inode); 575 unsigned int bsize = sdp->sd_sb.sb_bsize; 576 const unsigned int maxlen = bh_map->b_size >> inode->i_blkbits; 577 const u64 *arr = sdp->sd_heightsize; 578 __be64 *ptr; 579 u64 size; 580 struct metapath mp; 581 int ret; 582 int eob; 583 unsigned int len; 584 struct buffer_head *bh; 585 u8 height; 586 587 BUG_ON(maxlen == 0); 588 589 memset(mp.mp_bh, 0, sizeof(mp.mp_bh)); 590 bmap_lock(ip, create); 591 clear_buffer_mapped(bh_map); 592 clear_buffer_new(bh_map); 593 clear_buffer_boundary(bh_map); 594 trace_gfs2_bmap(ip, bh_map, lblock, create, 1); 595 if (gfs2_is_dir(ip)) { 596 bsize = sdp->sd_jbsize; 597 arr = sdp->sd_jheightsize; 598 } 599 600 ret = gfs2_meta_inode_buffer(ip, &mp.mp_bh[0]); 601 if (ret) 602 goto out; 603 604 height = ip->i_height; 605 size = (lblock + 1) * bsize; 606 while (size > arr[height]) 607 height++; 608 find_metapath(sdp, lblock, &mp, height); 609 ret = 1; 610 if (height > ip->i_height || gfs2_is_stuffed(ip)) 611 goto do_alloc; 612 ret = lookup_metapath(ip, &mp); 613 if (ret < 0) 614 goto out; 615 if (ret != ip->i_height) 616 goto do_alloc; 617 ptr = metapointer(ip->i_height - 1, &mp); 618 if (*ptr == 0) 619 goto do_alloc; 620 map_bh(bh_map, inode->i_sb, be64_to_cpu(*ptr)); 621 bh = mp.mp_bh[ip->i_height - 1]; 622 len = gfs2_extent_length(bh->b_data, bh->b_size, ptr, maxlen, &eob); 623 bh_map->b_size = (len << inode->i_blkbits); 624 if (eob) 625 set_buffer_boundary(bh_map); 626 ret = 0; 627 out: 628 release_metapath(&mp); 629 trace_gfs2_bmap(ip, bh_map, lblock, create, ret); 630 bmap_unlock(ip, create); 631 return ret; 632 633 do_alloc: 634 /* All allocations are done here, firstly check create flag */ 635 if (!create) { 636 BUG_ON(gfs2_is_stuffed(ip)); 637 ret = 0; 638 goto out; 639 } 640 641 /* At this point ret is the tree depth of already allocated blocks */ 642 ret = gfs2_bmap_alloc(inode, lblock, bh_map, &mp, ret, height, maxlen); 643 goto out; 644 } 645 646 /* 647 * Deprecated: do not use in new code 648 */ 649 int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen) 650 { 651 struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 }; 652 int ret; 653 int create = *new; 654 655 BUG_ON(!extlen); 656 BUG_ON(!dblock); 657 BUG_ON(!new); 658 659 bh.b_size = 1 << (inode->i_blkbits + (create ? 0 : 5)); 660 ret = gfs2_block_map(inode, lblock, &bh, create); 661 *extlen = bh.b_size >> inode->i_blkbits; 662 *dblock = bh.b_blocknr; 663 if (buffer_new(&bh)) 664 *new = 1; 665 else 666 *new = 0; 667 return ret; 668 } 669 670 /** 671 * recursive_scan - recursively scan through the end of a file 672 * @ip: the inode 673 * @dibh: the dinode buffer 674 * @mp: the path through the metadata to the point to start 675 * @height: the height the recursion is at 676 * @block: the indirect block to look at 677 * @first: 1 if this is the first block 678 * @bc: the call to make for each piece of metadata 679 * @data: data opaque to this function to pass to @bc 680 * 681 * When this is first called @height and @block should be zero and 682 * @first should be 1. 683 * 684 * Returns: errno 685 */ 686 687 static int recursive_scan(struct gfs2_inode *ip, struct buffer_head *dibh, 688 struct metapath *mp, unsigned int height, 689 u64 block, int first, block_call_t bc, 690 void *data) 691 { 692 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 693 struct buffer_head *bh = NULL; 694 __be64 *top, *bottom; 695 u64 bn; 696 int error; 697 int mh_size = sizeof(struct gfs2_meta_header); 698 699 if (!height) { 700 error = gfs2_meta_inode_buffer(ip, &bh); 701 if (error) 702 return error; 703 dibh = bh; 704 705 top = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + mp->mp_list[0]; 706 bottom = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + sdp->sd_diptrs; 707 } else { 708 error = gfs2_meta_indirect_buffer(ip, height, block, 0, &bh); 709 if (error) 710 return error; 711 712 top = (__be64 *)(bh->b_data + mh_size) + 713 (first ? mp->mp_list[height] : 0); 714 715 bottom = (__be64 *)(bh->b_data + mh_size) + sdp->sd_inptrs; 716 } 717 718 error = bc(ip, dibh, bh, top, bottom, height, data); 719 if (error) 720 goto out; 721 722 if (height < ip->i_height - 1) 723 for (; top < bottom; top++, first = 0) { 724 if (!*top) 725 continue; 726 727 bn = be64_to_cpu(*top); 728 729 error = recursive_scan(ip, dibh, mp, height + 1, bn, 730 first, bc, data); 731 if (error) 732 break; 733 } 734 735 out: 736 brelse(bh); 737 return error; 738 } 739 740 /** 741 * do_strip - Look for a layer a particular layer of the file and strip it off 742 * @ip: the inode 743 * @dibh: the dinode buffer 744 * @bh: A buffer of pointers 745 * @top: The first pointer in the buffer 746 * @bottom: One more than the last pointer 747 * @height: the height this buffer is at 748 * @data: a pointer to a struct strip_mine 749 * 750 * Returns: errno 751 */ 752 753 static int do_strip(struct gfs2_inode *ip, struct buffer_head *dibh, 754 struct buffer_head *bh, __be64 *top, __be64 *bottom, 755 unsigned int height, void *data) 756 { 757 struct strip_mine *sm = data; 758 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 759 struct gfs2_rgrp_list rlist; 760 u64 bn, bstart; 761 u32 blen; 762 __be64 *p; 763 unsigned int rg_blocks = 0; 764 int metadata; 765 unsigned int revokes = 0; 766 int x; 767 int error; 768 769 if (!*top) 770 sm->sm_first = 0; 771 772 if (height != sm->sm_height) 773 return 0; 774 775 if (sm->sm_first) { 776 top++; 777 sm->sm_first = 0; 778 } 779 780 metadata = (height != ip->i_height - 1); 781 if (metadata) 782 revokes = (height) ? sdp->sd_inptrs : sdp->sd_diptrs; 783 784 error = gfs2_rindex_hold(sdp, &ip->i_alloc->al_ri_gh); 785 if (error) 786 return error; 787 788 memset(&rlist, 0, sizeof(struct gfs2_rgrp_list)); 789 bstart = 0; 790 blen = 0; 791 792 for (p = top; p < bottom; p++) { 793 if (!*p) 794 continue; 795 796 bn = be64_to_cpu(*p); 797 798 if (bstart + blen == bn) 799 blen++; 800 else { 801 if (bstart) 802 gfs2_rlist_add(sdp, &rlist, bstart); 803 804 bstart = bn; 805 blen = 1; 806 } 807 } 808 809 if (bstart) 810 gfs2_rlist_add(sdp, &rlist, bstart); 811 else 812 goto out; /* Nothing to do */ 813 814 gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE); 815 816 for (x = 0; x < rlist.rl_rgrps; x++) { 817 struct gfs2_rgrpd *rgd; 818 rgd = rlist.rl_ghs[x].gh_gl->gl_object; 819 rg_blocks += rgd->rd_length; 820 } 821 822 error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs); 823 if (error) 824 goto out_rlist; 825 826 error = gfs2_trans_begin(sdp, rg_blocks + RES_DINODE + 827 RES_INDIRECT + RES_STATFS + RES_QUOTA, 828 revokes); 829 if (error) 830 goto out_rg_gunlock; 831 832 down_write(&ip->i_rw_mutex); 833 834 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 835 gfs2_trans_add_bh(ip->i_gl, bh, 1); 836 837 bstart = 0; 838 blen = 0; 839 840 for (p = top; p < bottom; p++) { 841 if (!*p) 842 continue; 843 844 bn = be64_to_cpu(*p); 845 846 if (bstart + blen == bn) 847 blen++; 848 else { 849 if (bstart) { 850 if (metadata) 851 gfs2_free_meta(ip, bstart, blen); 852 else 853 gfs2_free_data(ip, bstart, blen); 854 } 855 856 bstart = bn; 857 blen = 1; 858 } 859 860 *p = 0; 861 gfs2_add_inode_blocks(&ip->i_inode, -1); 862 } 863 if (bstart) { 864 if (metadata) 865 gfs2_free_meta(ip, bstart, blen); 866 else 867 gfs2_free_data(ip, bstart, blen); 868 } 869 870 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; 871 872 gfs2_dinode_out(ip, dibh->b_data); 873 874 up_write(&ip->i_rw_mutex); 875 876 gfs2_trans_end(sdp); 877 878 out_rg_gunlock: 879 gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs); 880 out_rlist: 881 gfs2_rlist_free(&rlist); 882 out: 883 gfs2_glock_dq_uninit(&ip->i_alloc->al_ri_gh); 884 return error; 885 } 886 887 /** 888 * do_grow - Make a file look bigger than it is 889 * @ip: the inode 890 * @size: the size to set the file to 891 * 892 * Called with an exclusive lock on @ip. 893 * 894 * Returns: errno 895 */ 896 897 static int do_grow(struct gfs2_inode *ip, u64 size) 898 { 899 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 900 struct gfs2_alloc *al; 901 struct buffer_head *dibh; 902 int error; 903 904 al = gfs2_alloc_get(ip); 905 if (!al) 906 return -ENOMEM; 907 908 error = gfs2_quota_lock_check(ip); 909 if (error) 910 goto out; 911 912 al->al_requested = sdp->sd_max_height + RES_DATA; 913 914 error = gfs2_inplace_reserve(ip); 915 if (error) 916 goto out_gunlock_q; 917 918 error = gfs2_trans_begin(sdp, 919 sdp->sd_max_height + al->al_rgd->rd_length + 920 RES_JDATA + RES_DINODE + RES_STATFS + RES_QUOTA, 0); 921 if (error) 922 goto out_ipres; 923 924 error = gfs2_meta_inode_buffer(ip, &dibh); 925 if (error) 926 goto out_end_trans; 927 928 if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { 929 if (gfs2_is_stuffed(ip)) { 930 error = gfs2_unstuff_dinode(ip, NULL); 931 if (error) 932 goto out_brelse; 933 } 934 } 935 936 ip->i_disksize = size; 937 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; 938 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 939 gfs2_dinode_out(ip, dibh->b_data); 940 941 out_brelse: 942 brelse(dibh); 943 out_end_trans: 944 gfs2_trans_end(sdp); 945 out_ipres: 946 gfs2_inplace_release(ip); 947 out_gunlock_q: 948 gfs2_quota_unlock(ip); 949 out: 950 gfs2_alloc_put(ip); 951 return error; 952 } 953 954 955 /** 956 * gfs2_block_truncate_page - Deal with zeroing out data for truncate 957 * 958 * This is partly borrowed from ext3. 959 */ 960 static int gfs2_block_truncate_page(struct address_space *mapping) 961 { 962 struct inode *inode = mapping->host; 963 struct gfs2_inode *ip = GFS2_I(inode); 964 loff_t from = inode->i_size; 965 unsigned long index = from >> PAGE_CACHE_SHIFT; 966 unsigned offset = from & (PAGE_CACHE_SIZE-1); 967 unsigned blocksize, iblock, length, pos; 968 struct buffer_head *bh; 969 struct page *page; 970 int err; 971 972 page = grab_cache_page(mapping, index); 973 if (!page) 974 return 0; 975 976 blocksize = inode->i_sb->s_blocksize; 977 length = blocksize - (offset & (blocksize - 1)); 978 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); 979 980 if (!page_has_buffers(page)) 981 create_empty_buffers(page, blocksize, 0); 982 983 /* Find the buffer that contains "offset" */ 984 bh = page_buffers(page); 985 pos = blocksize; 986 while (offset >= pos) { 987 bh = bh->b_this_page; 988 iblock++; 989 pos += blocksize; 990 } 991 992 err = 0; 993 994 if (!buffer_mapped(bh)) { 995 gfs2_block_map(inode, iblock, bh, 0); 996 /* unmapped? It's a hole - nothing to do */ 997 if (!buffer_mapped(bh)) 998 goto unlock; 999 } 1000 1001 /* Ok, it's mapped. Make sure it's up-to-date */ 1002 if (PageUptodate(page)) 1003 set_buffer_uptodate(bh); 1004 1005 if (!buffer_uptodate(bh)) { 1006 err = -EIO; 1007 ll_rw_block(READ, 1, &bh); 1008 wait_on_buffer(bh); 1009 /* Uhhuh. Read error. Complain and punt. */ 1010 if (!buffer_uptodate(bh)) 1011 goto unlock; 1012 err = 0; 1013 } 1014 1015 if (!gfs2_is_writeback(ip)) 1016 gfs2_trans_add_bh(ip->i_gl, bh, 0); 1017 1018 zero_user(page, offset, length); 1019 mark_buffer_dirty(bh); 1020 unlock: 1021 unlock_page(page); 1022 page_cache_release(page); 1023 return err; 1024 } 1025 1026 static int trunc_start(struct gfs2_inode *ip, u64 size) 1027 { 1028 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 1029 struct buffer_head *dibh; 1030 int journaled = gfs2_is_jdata(ip); 1031 int error; 1032 1033 error = gfs2_trans_begin(sdp, 1034 RES_DINODE + (journaled ? RES_JDATA : 0), 0); 1035 if (error) 1036 return error; 1037 1038 error = gfs2_meta_inode_buffer(ip, &dibh); 1039 if (error) 1040 goto out; 1041 1042 if (gfs2_is_stuffed(ip)) { 1043 u64 dsize = size + sizeof(struct gfs2_inode); 1044 ip->i_disksize = size; 1045 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; 1046 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 1047 gfs2_dinode_out(ip, dibh->b_data); 1048 if (dsize > dibh->b_size) 1049 dsize = dibh->b_size; 1050 gfs2_buffer_clear_tail(dibh, dsize); 1051 error = 1; 1052 } else { 1053 if (size & (u64)(sdp->sd_sb.sb_bsize - 1)) 1054 error = gfs2_block_truncate_page(ip->i_inode.i_mapping); 1055 1056 if (!error) { 1057 ip->i_disksize = size; 1058 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; 1059 ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG; 1060 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 1061 gfs2_dinode_out(ip, dibh->b_data); 1062 } 1063 } 1064 1065 brelse(dibh); 1066 1067 out: 1068 gfs2_trans_end(sdp); 1069 return error; 1070 } 1071 1072 static int trunc_dealloc(struct gfs2_inode *ip, u64 size) 1073 { 1074 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 1075 unsigned int height = ip->i_height; 1076 u64 lblock; 1077 struct metapath mp; 1078 int error; 1079 1080 if (!size) 1081 lblock = 0; 1082 else 1083 lblock = (size - 1) >> sdp->sd_sb.sb_bsize_shift; 1084 1085 find_metapath(sdp, lblock, &mp, ip->i_height); 1086 if (!gfs2_alloc_get(ip)) 1087 return -ENOMEM; 1088 1089 error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); 1090 if (error) 1091 goto out; 1092 1093 while (height--) { 1094 struct strip_mine sm; 1095 sm.sm_first = !!size; 1096 sm.sm_height = height; 1097 1098 error = recursive_scan(ip, NULL, &mp, 0, 0, 1, do_strip, &sm); 1099 if (error) 1100 break; 1101 } 1102 1103 gfs2_quota_unhold(ip); 1104 1105 out: 1106 gfs2_alloc_put(ip); 1107 return error; 1108 } 1109 1110 static int trunc_end(struct gfs2_inode *ip) 1111 { 1112 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 1113 struct buffer_head *dibh; 1114 int error; 1115 1116 error = gfs2_trans_begin(sdp, RES_DINODE, 0); 1117 if (error) 1118 return error; 1119 1120 down_write(&ip->i_rw_mutex); 1121 1122 error = gfs2_meta_inode_buffer(ip, &dibh); 1123 if (error) 1124 goto out; 1125 1126 if (!ip->i_disksize) { 1127 ip->i_height = 0; 1128 ip->i_goal = ip->i_no_addr; 1129 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); 1130 } 1131 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; 1132 ip->i_diskflags &= ~GFS2_DIF_TRUNC_IN_PROG; 1133 1134 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 1135 gfs2_dinode_out(ip, dibh->b_data); 1136 brelse(dibh); 1137 1138 out: 1139 up_write(&ip->i_rw_mutex); 1140 gfs2_trans_end(sdp); 1141 return error; 1142 } 1143 1144 /** 1145 * do_shrink - make a file smaller 1146 * @ip: the inode 1147 * @size: the size to make the file 1148 * @truncator: function to truncate the last partial block 1149 * 1150 * Called with an exclusive lock on @ip. 1151 * 1152 * Returns: errno 1153 */ 1154 1155 static int do_shrink(struct gfs2_inode *ip, u64 size) 1156 { 1157 int error; 1158 1159 error = trunc_start(ip, size); 1160 if (error < 0) 1161 return error; 1162 if (error > 0) 1163 return 0; 1164 1165 error = trunc_dealloc(ip, size); 1166 if (!error) 1167 error = trunc_end(ip); 1168 1169 return error; 1170 } 1171 1172 static int do_touch(struct gfs2_inode *ip, u64 size) 1173 { 1174 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 1175 struct buffer_head *dibh; 1176 int error; 1177 1178 error = gfs2_trans_begin(sdp, RES_DINODE, 0); 1179 if (error) 1180 return error; 1181 1182 down_write(&ip->i_rw_mutex); 1183 1184 error = gfs2_meta_inode_buffer(ip, &dibh); 1185 if (error) 1186 goto do_touch_out; 1187 1188 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; 1189 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 1190 gfs2_dinode_out(ip, dibh->b_data); 1191 brelse(dibh); 1192 1193 do_touch_out: 1194 up_write(&ip->i_rw_mutex); 1195 gfs2_trans_end(sdp); 1196 return error; 1197 } 1198 1199 /** 1200 * gfs2_truncatei - make a file a given size 1201 * @ip: the inode 1202 * @size: the size to make the file 1203 * @truncator: function to truncate the last partial block 1204 * 1205 * The file size can grow, shrink, or stay the same size. 1206 * 1207 * Returns: errno 1208 */ 1209 1210 int gfs2_truncatei(struct gfs2_inode *ip, u64 size) 1211 { 1212 int error; 1213 1214 if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), S_ISREG(ip->i_inode.i_mode))) 1215 return -EINVAL; 1216 1217 if (size > ip->i_disksize) 1218 error = do_grow(ip, size); 1219 else if (size < ip->i_disksize) 1220 error = do_shrink(ip, size); 1221 else 1222 /* update time stamps */ 1223 error = do_touch(ip, size); 1224 1225 return error; 1226 } 1227 1228 int gfs2_truncatei_resume(struct gfs2_inode *ip) 1229 { 1230 int error; 1231 error = trunc_dealloc(ip, ip->i_disksize); 1232 if (!error) 1233 error = trunc_end(ip); 1234 return error; 1235 } 1236 1237 int gfs2_file_dealloc(struct gfs2_inode *ip) 1238 { 1239 return trunc_dealloc(ip, 0); 1240 } 1241 1242 /** 1243 * gfs2_write_alloc_required - figure out if a write will require an allocation 1244 * @ip: the file being written to 1245 * @offset: the offset to write to 1246 * @len: the number of bytes being written 1247 * @alloc_required: set to 1 if an alloc is required, 0 otherwise 1248 * 1249 * Returns: errno 1250 */ 1251 1252 int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, 1253 unsigned int len, int *alloc_required) 1254 { 1255 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 1256 struct buffer_head bh; 1257 unsigned int shift; 1258 u64 lblock, lblock_stop, size; 1259 u64 end_of_file; 1260 1261 *alloc_required = 0; 1262 1263 if (!len) 1264 return 0; 1265 1266 if (gfs2_is_stuffed(ip)) { 1267 if (offset + len > 1268 sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) 1269 *alloc_required = 1; 1270 return 0; 1271 } 1272 1273 *alloc_required = 1; 1274 shift = sdp->sd_sb.sb_bsize_shift; 1275 BUG_ON(gfs2_is_dir(ip)); 1276 end_of_file = (ip->i_disksize + sdp->sd_sb.sb_bsize - 1) >> shift; 1277 lblock = offset >> shift; 1278 lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift; 1279 if (lblock_stop > end_of_file) 1280 return 0; 1281 1282 size = (lblock_stop - lblock) << shift; 1283 do { 1284 bh.b_state = 0; 1285 bh.b_size = size; 1286 gfs2_block_map(&ip->i_inode, lblock, &bh, 0); 1287 if (!buffer_mapped(&bh)) 1288 return 0; 1289 size -= bh.b_size; 1290 lblock += (bh.b_size >> ip->i_inode.i_blkbits); 1291 } while(size > 0); 1292 1293 *alloc_required = 0; 1294 return 0; 1295 } 1296 1297