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/slab.h> 11#include <linux/spinlock.h> 12#include <linux/completion.h> 13#include <linux/buffer_head.h> 14#include <linux/gfs2_ondisk.h> 15#include <linux/crc32.h> 16#include <linux/lm_interface.h> 17 18#include "gfs2.h" 19#include "incore.h" 20#include "bmap.h" 21#include "glock.h" 22#include "inode.h" 23#include "meta_io.h" 24#include "quota.h" 25#include "rgrp.h" 26#include "trans.h" 27#include "dir.h" 28#include "util.h" 29#include "ops_address.h" 30 31/* This doesn't need to be that large as max 64 bit pointers in a 4k 32 * block is 512, so __u16 is fine for that. It saves stack space to 33 * keep it small. 34 */ 35struct metapath { 36 __u16 mp_list[GFS2_MAX_META_HEIGHT]; 37}; 38 39typedef int (*block_call_t) (struct gfs2_inode *ip, struct buffer_head *dibh, 40 struct buffer_head *bh, __be64 *top, 41 __be64 *bottom, unsigned int height, 42 void *data); 43 44struct strip_mine { 45 int sm_first; 46 unsigned int sm_height; 47}; 48 49/** 50 * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page 51 * @ip: the inode 52 * @dibh: the dinode buffer 53 * @block: the block number that was allocated 54 * @private: any locked page held by the caller process 55 * 56 * Returns: errno 57 */ 58 59static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh, 60 u64 block, struct page *page) 61{ 62 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 63 struct inode *inode = &ip->i_inode; 64 struct buffer_head *bh; 65 int release = 0; 66 67 if (!page || page->index) { 68 page = grab_cache_page(inode->i_mapping, 0); 69 if (!page) 70 return -ENOMEM; 71 release = 1; 72 } 73 74 if (!PageUptodate(page)) { 75 void *kaddr = kmap(page); 76 77 memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), 78 ip->i_di.di_size); 79 memset(kaddr + ip->i_di.di_size, 0, 80 PAGE_CACHE_SIZE - ip->i_di.di_size); 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 (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) 97 gfs2_trans_add_bh(ip->i_gl, bh, 0); 98 mark_buffer_dirty(bh); 99 100 if (release) { 101 unlock_page(page); 102 page_cache_release(page); 103 } 104 105 return 0; 106} 107 108/** 109 * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big 110 * @ip: The GFS2 inode to unstuff 111 * @unstuffer: the routine that handles unstuffing a non-zero length file 112 * @private: private data for the unstuffer 113 * 114 * This routine unstuffs a dinode and returns it to a "normal" state such 115 * that the height can be grown in the traditional way. 116 * 117 * Returns: errno 118 */ 119 120int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page) 121{ 122 struct buffer_head *bh, *dibh; 123 struct gfs2_dinode *di; 124 u64 block = 0; 125 int isdir = gfs2_is_dir(ip); 126 int error; 127 128 down_write(&ip->i_rw_mutex); 129 130 error = gfs2_meta_inode_buffer(ip, &dibh); 131 if (error) 132 goto out; 133 134 if (ip->i_di.di_size) { 135 /* Get a free block, fill it with the stuffed data, 136 and write it out to disk */ 137 138 if (isdir) { 139 block = gfs2_alloc_meta(ip); 140 141 error = gfs2_dir_get_new_buffer(ip, block, &bh); 142 if (error) 143 goto out_brelse; 144 gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_meta_header), 145 dibh, sizeof(struct gfs2_dinode)); 146 brelse(bh); 147 } else { 148 block = gfs2_alloc_data(ip); 149 150 error = gfs2_unstuffer_page(ip, dibh, block, page); 151 if (error) 152 goto out_brelse; 153 } 154 } 155 156 /* Set up the pointer to the new block */ 157 158 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 159 di = (struct gfs2_dinode *)dibh->b_data; 160 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); 161 162 if (ip->i_di.di_size) { 163 *(__be64 *)(di + 1) = cpu_to_be64(block); 164 ip->i_di.di_blocks++; 165 gfs2_set_inode_blocks(&ip->i_inode); 166 di->di_blocks = cpu_to_be64(ip->i_di.di_blocks); 167 } 168 169 ip->i_di.di_height = 1; 170 di->di_height = cpu_to_be16(1); 171 172out_brelse: 173 brelse(dibh); 174out: 175 up_write(&ip->i_rw_mutex); 176 return error; 177} 178 179/** 180 * calc_tree_height - Calculate the height of a metadata tree 181 * @ip: The GFS2 inode 182 * @size: The proposed size of the file 183 * 184 * Work out how tall a metadata tree needs to be in order to accommodate a 185 * file of a particular size. If size is less than the current size of 186 * the inode, then the current size of the inode is used instead of the 187 * supplied one. 188 * 189 * Returns: the height the tree should be 190 */ 191 192static unsigned int calc_tree_height(struct gfs2_inode *ip, u64 size) 193{ 194 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 195 u64 *arr; 196 unsigned int max, height; 197 198 if (ip->i_di.di_size > size) 199 size = ip->i_di.di_size; 200 201 if (gfs2_is_dir(ip)) { 202 arr = sdp->sd_jheightsize; 203 max = sdp->sd_max_jheight; 204 } else { 205 arr = sdp->sd_heightsize; 206 max = sdp->sd_max_height; 207 } 208 209 for (height = 0; height < max; height++) 210 if (arr[height] >= size) 211 break; 212 213 return height; 214} 215 216/** 217 * build_height - Build a metadata tree of the requested height 218 * @ip: The GFS2 inode 219 * @height: The height to build to 220 * 221 * 222 * Returns: errno 223 */ 224 225static int build_height(struct inode *inode, unsigned height) 226{ 227 struct gfs2_inode *ip = GFS2_I(inode); 228 unsigned new_height = height - ip->i_di.di_height; 229 struct buffer_head *dibh; 230 struct buffer_head *blocks[GFS2_MAX_META_HEIGHT]; 231 struct gfs2_dinode *di; 232 int error; 233 __be64 *bp; 234 u64 bn; 235 unsigned n; 236 237 if (height <= ip->i_di.di_height) 238 return 0; 239 240 error = gfs2_meta_inode_buffer(ip, &dibh); 241 if (error) 242 return error; 243 244 for(n = 0; n < new_height; n++) { 245 bn = gfs2_alloc_meta(ip); 246 blocks[n] = gfs2_meta_new(ip->i_gl, bn); 247 gfs2_trans_add_bh(ip->i_gl, blocks[n], 1); 248 } 249 250 n = 0; 251 bn = blocks[0]->b_blocknr; 252 if (new_height > 1) { 253 for(; n < new_height-1; n++) { 254 gfs2_metatype_set(blocks[n], GFS2_METATYPE_IN, 255 GFS2_FORMAT_IN); 256 gfs2_buffer_clear_tail(blocks[n], 257 sizeof(struct gfs2_meta_header)); 258 bp = (__be64 *)(blocks[n]->b_data + 259 sizeof(struct gfs2_meta_header)); 260 *bp = cpu_to_be64(blocks[n+1]->b_blocknr); 261 brelse(blocks[n]); 262 blocks[n] = NULL; 263 } 264 } 265 gfs2_metatype_set(blocks[n], GFS2_METATYPE_IN, GFS2_FORMAT_IN); 266 gfs2_buffer_copy_tail(blocks[n], sizeof(struct gfs2_meta_header), 267 dibh, sizeof(struct gfs2_dinode)); 268 brelse(blocks[n]); 269 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 270 di = (struct gfs2_dinode *)dibh->b_data; 271 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); 272 *(__be64 *)(di + 1) = cpu_to_be64(bn); 273 ip->i_di.di_height += new_height; 274 ip->i_di.di_blocks += new_height; 275 gfs2_set_inode_blocks(&ip->i_inode); 276 di->di_height = cpu_to_be16(ip->i_di.di_height); 277 di->di_blocks = cpu_to_be64(ip->i_di.di_blocks); 278 brelse(dibh); 279 return error; 280} 281 282/** 283 * find_metapath - Find path through the metadata tree 284 * @ip: The inode pointer 285 * @mp: The metapath to return the result in 286 * @block: The disk block to look up 287 * 288 * This routine returns a struct metapath structure that defines a path 289 * through the metadata of inode "ip" to get to block "block". 290 * 291 * Example: 292 * Given: "ip" is a height 3 file, "offset" is 101342453, and this is a 293 * filesystem with a blocksize of 4096. 294 * 295 * find_metapath() would return a struct metapath structure set to: 296 * mp_offset = 101342453, mp_height = 3, mp_list[0] = 0, mp_list[1] = 48, 297 * and mp_list[2] = 165. 298 * 299 * That means that in order to get to the block containing the byte at 300 * offset 101342453, we would load the indirect block pointed to by pointer 301 * 0 in the dinode. We would then load the indirect block pointed to by 302 * pointer 48 in that indirect block. We would then load the data block 303 * pointed to by pointer 165 in that indirect block. 304 * 305 * ---------------------------------------- 306 * | Dinode | | 307 * | | 4| 308 * | |0 1 2 3 4 5 9| 309 * | | 6| 310 * ---------------------------------------- 311 * | 312 * | 313 * V 314 * ---------------------------------------- 315 * | Indirect Block | 316 * | 5| 317 * | 4 4 4 4 4 5 5 1| 318 * |0 5 6 7 8 9 0 1 2| 319 * ---------------------------------------- 320 * | 321 * | 322 * V 323 * ---------------------------------------- 324 * | Indirect Block | 325 * | 1 1 1 1 1 5| 326 * | 6 6 6 6 6 1| 327 * |0 3 4 5 6 7 2| 328 * ---------------------------------------- 329 * | 330 * | 331 * V 332 * ---------------------------------------- 333 * | Data block containing offset | 334 * | 101342453 | 335 * | | 336 * | | 337 * ---------------------------------------- 338 * 339 */ 340 341static void find_metapath(struct gfs2_inode *ip, u64 block, 342 struct metapath *mp) 343{ 344 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 345 u64 b = block; 346 unsigned int i; 347 348 for (i = ip->i_di.di_height; i--;) 349 mp->mp_list[i] = do_div(b, sdp->sd_inptrs); 350 351} 352 353/** 354 * metapointer - Return pointer to start of metadata in a buffer 355 * @bh: The buffer 356 * @height: The metadata height (0 = dinode) 357 * @mp: The metapath 358 * 359 * Return a pointer to the block number of the next height of the metadata 360 * tree given a buffer containing the pointer to the current height of the 361 * metadata tree. 362 */ 363 364static inline __be64 *metapointer(struct buffer_head *bh, int *boundary, 365 unsigned int height, const struct metapath *mp) 366{ 367 unsigned int head_size = (height > 0) ? 368 sizeof(struct gfs2_meta_header) : sizeof(struct gfs2_dinode); 369 __be64 *ptr; 370 *boundary = 0; 371 ptr = ((__be64 *)(bh->b_data + head_size)) + mp->mp_list[height]; 372 if (ptr + 1 == (__be64 *)(bh->b_data + bh->b_size)) 373 *boundary = 1; 374 return ptr; 375} 376 377/** 378 * lookup_block - Get the next metadata block in metadata tree 379 * @ip: The GFS2 inode 380 * @bh: Buffer containing the pointers to metadata blocks 381 * @height: The height of the tree (0 = dinode) 382 * @mp: The metapath 383 * @create: Non-zero if we may create a new meatdata block 384 * @new: Used to indicate if we did create a new metadata block 385 * @block: the returned disk block number 386 * 387 * Given a metatree, complete to a particular height, checks to see if the next 388 * height of the tree exists. If not the next height of the tree is created. 389 * The block number of the next height of the metadata tree is returned. 390 * 391 */ 392 393static int lookup_block(struct gfs2_inode *ip, struct buffer_head *bh, 394 unsigned int height, struct metapath *mp, int create, 395 int *new, u64 *block) 396{ 397 int boundary; 398 __be64 *ptr = metapointer(bh, &boundary, height, mp); 399 400 if (*ptr) { 401 *block = be64_to_cpu(*ptr); 402 return boundary; 403 } 404 405 *block = 0; 406 407 if (!create) 408 return 0; 409 410 if (height == ip->i_di.di_height - 1 && !gfs2_is_dir(ip)) 411 *block = gfs2_alloc_data(ip); 412 else 413 *block = gfs2_alloc_meta(ip); 414 415 gfs2_trans_add_bh(ip->i_gl, bh, 1); 416 417 *ptr = cpu_to_be64(*block); 418 ip->i_di.di_blocks++; 419 gfs2_set_inode_blocks(&ip->i_inode); 420 421 *new = 1; 422 return 0; 423} 424 425static inline void bmap_lock(struct inode *inode, int create) 426{ 427 struct gfs2_inode *ip = GFS2_I(inode); 428 if (create) 429 down_write(&ip->i_rw_mutex); 430 else 431 down_read(&ip->i_rw_mutex); 432} 433 434static inline void bmap_unlock(struct inode *inode, int create) 435{ 436 struct gfs2_inode *ip = GFS2_I(inode); 437 if (create) 438 up_write(&ip->i_rw_mutex); 439 else 440 up_read(&ip->i_rw_mutex); 441} 442 443/** 444 * gfs2_block_map - Map a block from an inode to a disk block 445 * @inode: The inode 446 * @lblock: The logical block number 447 * @bh_map: The bh to be mapped 448 * 449 * Find the block number on the current device which corresponds to an 450 * inode's block. If the block had to be created, "new" will be set. 451 * 452 * Returns: errno 453 */ 454 455int gfs2_block_map(struct inode *inode, u64 lblock, int create, 456 struct buffer_head *bh_map) 457{ 458 struct gfs2_inode *ip = GFS2_I(inode); 459 struct gfs2_sbd *sdp = GFS2_SB(inode); 460 struct buffer_head *bh; 461 unsigned int bsize; 462 unsigned int height; 463 unsigned int end_of_metadata; 464 unsigned int x; 465 int error = 0; 466 int new = 0; 467 u64 dblock = 0; 468 int boundary; 469 unsigned int maxlen = bh_map->b_size >> inode->i_blkbits; 470 struct metapath mp; 471 u64 size; 472 473 BUG_ON(maxlen == 0); 474 475 if (gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip))) 476 return 0; 477 478 bmap_lock(inode, create); 479 clear_buffer_mapped(bh_map); 480 clear_buffer_new(bh_map); 481 clear_buffer_boundary(bh_map); 482 bsize = gfs2_is_dir(ip) ? sdp->sd_jbsize : sdp->sd_sb.sb_bsize; 483 size = (lblock + 1) * bsize; 484 485 if (size > ip->i_di.di_size) { 486 height = calc_tree_height(ip, size); 487 if (ip->i_di.di_height < height) { 488 if (!create) 489 goto out_ok; 490 491 error = build_height(inode, height); 492 if (error) 493 goto out_fail; 494 } 495 } 496 497 find_metapath(ip, lblock, &mp); 498 end_of_metadata = ip->i_di.di_height - 1; 499 error = gfs2_meta_inode_buffer(ip, &bh); 500 if (error) 501 goto out_fail; 502 503 for (x = 0; x < end_of_metadata; x++) { 504 lookup_block(ip, bh, x, &mp, create, &new, &dblock); 505 brelse(bh); 506 if (!dblock) 507 goto out_ok; 508 509 error = gfs2_meta_indirect_buffer(ip, x+1, dblock, new, &bh); 510 if (error) 511 goto out_fail; 512 } 513 514 boundary = lookup_block(ip, bh, end_of_metadata, &mp, create, &new, &dblock); 515 if (dblock) { 516 map_bh(bh_map, inode->i_sb, dblock); 517 if (boundary) 518 set_buffer_boundary(bh_map); 519 if (new) { 520 struct buffer_head *dibh; 521 error = gfs2_meta_inode_buffer(ip, &dibh); 522 if (!error) { 523 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 524 gfs2_dinode_out(ip, dibh->b_data); 525 brelse(dibh); 526 } 527 set_buffer_new(bh_map); 528 goto out_brelse; 529 } 530 while(--maxlen && !buffer_boundary(bh_map)) { 531 u64 eblock; 532 533 mp.mp_list[end_of_metadata]++; 534 boundary = lookup_block(ip, bh, end_of_metadata, &mp, 0, &new, &eblock); 535 if (eblock != ++dblock) 536 break; 537 bh_map->b_size += (1 << inode->i_blkbits); 538 if (boundary) 539 set_buffer_boundary(bh_map); 540 } 541 } 542out_brelse: 543 brelse(bh); 544out_ok: 545 error = 0; 546out_fail: 547 bmap_unlock(inode, create); 548 return error; 549} 550 551int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen) 552{ 553 struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 }; 554 int ret; 555 int create = *new; 556 557 BUG_ON(!extlen); 558 BUG_ON(!dblock); 559 BUG_ON(!new); 560 561 bh.b_size = 1 << (inode->i_blkbits + 5); 562 ret = gfs2_block_map(inode, lblock, create, &bh); 563 *extlen = bh.b_size >> inode->i_blkbits; 564 *dblock = bh.b_blocknr; 565 if (buffer_new(&bh)) 566 *new = 1; 567 else 568 *new = 0; 569 return ret; 570} 571 572/** 573 * recursive_scan - recursively scan through the end of a file 574 * @ip: the inode 575 * @dibh: the dinode buffer 576 * @mp: the path through the metadata to the point to start 577 * @height: the height the recursion is at 578 * @block: the indirect block to look at 579 * @first: 1 if this is the first block 580 * @bc: the call to make for each piece of metadata 581 * @data: data opaque to this function to pass to @bc 582 * 583 * When this is first called @height and @block should be zero and 584 * @first should be 1. 585 * 586 * Returns: errno 587 */ 588 589static int recursive_scan(struct gfs2_inode *ip, struct buffer_head *dibh, 590 struct metapath *mp, unsigned int height, 591 u64 block, int first, block_call_t bc, 592 void *data) 593{ 594 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 595 struct buffer_head *bh = NULL; 596 __be64 *top, *bottom; 597 u64 bn; 598 int error; 599 int mh_size = sizeof(struct gfs2_meta_header); 600 601 if (!height) { 602 error = gfs2_meta_inode_buffer(ip, &bh); 603 if (error) 604 return error; 605 dibh = bh; 606 607 top = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + mp->mp_list[0]; 608 bottom = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + sdp->sd_diptrs; 609 } else { 610 error = gfs2_meta_indirect_buffer(ip, height, block, 0, &bh); 611 if (error) 612 return error; 613 614 top = (__be64 *)(bh->b_data + mh_size) + 615 (first ? mp->mp_list[height] : 0); 616 617 bottom = (__be64 *)(bh->b_data + mh_size) + sdp->sd_inptrs; 618 } 619 620 error = bc(ip, dibh, bh, top, bottom, height, data); 621 if (error) 622 goto out; 623 624 if (height < ip->i_di.di_height - 1) 625 for (; top < bottom; top++, first = 0) { 626 if (!*top) 627 continue; 628 629 bn = be64_to_cpu(*top); 630 631 error = recursive_scan(ip, dibh, mp, height + 1, bn, 632 first, bc, data); 633 if (error) 634 break; 635 } 636 637out: 638 brelse(bh); 639 return error; 640} 641 642/** 643 * do_strip - Look for a layer a particular layer of the file and strip it off 644 * @ip: the inode 645 * @dibh: the dinode buffer 646 * @bh: A buffer of pointers 647 * @top: The first pointer in the buffer 648 * @bottom: One more than the last pointer 649 * @height: the height this buffer is at 650 * @data: a pointer to a struct strip_mine 651 * 652 * Returns: errno 653 */ 654 655static int do_strip(struct gfs2_inode *ip, struct buffer_head *dibh, 656 struct buffer_head *bh, __be64 *top, __be64 *bottom, 657 unsigned int height, void *data) 658{ 659 struct strip_mine *sm = data; 660 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 661 struct gfs2_rgrp_list rlist; 662 u64 bn, bstart; 663 u32 blen; 664 __be64 *p; 665 unsigned int rg_blocks = 0; 666 int metadata; 667 unsigned int revokes = 0; 668 int x; 669 int error; 670 671 if (!*top) 672 sm->sm_first = 0; 673 674 if (height != sm->sm_height) 675 return 0; 676 677 if (sm->sm_first) { 678 top++; 679 sm->sm_first = 0; 680 } 681 682 metadata = (height != ip->i_di.di_height - 1); 683 if (metadata) 684 revokes = (height) ? sdp->sd_inptrs : sdp->sd_diptrs; 685 686 error = gfs2_rindex_hold(sdp, &ip->i_alloc.al_ri_gh); 687 if (error) 688 return error; 689 690 memset(&rlist, 0, sizeof(struct gfs2_rgrp_list)); 691 bstart = 0; 692 blen = 0; 693 694 for (p = top; p < bottom; p++) { 695 if (!*p) 696 continue; 697 698 bn = be64_to_cpu(*p); 699 700 if (bstart + blen == bn) 701 blen++; 702 else { 703 if (bstart) 704 gfs2_rlist_add(sdp, &rlist, bstart); 705 706 bstart = bn; 707 blen = 1; 708 } 709 } 710 711 if (bstart) 712 gfs2_rlist_add(sdp, &rlist, bstart); 713 else 714 goto out; /* Nothing to do */ 715 716 gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE, 0); 717 718 for (x = 0; x < rlist.rl_rgrps; x++) { 719 struct gfs2_rgrpd *rgd; 720 rgd = rlist.rl_ghs[x].gh_gl->gl_object; 721 rg_blocks += rgd->rd_ri.ri_length; 722 } 723 724 error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs); 725 if (error) 726 goto out_rlist; 727 728 error = gfs2_trans_begin(sdp, rg_blocks + RES_DINODE + 729 RES_INDIRECT + RES_STATFS + RES_QUOTA, 730 revokes); 731 if (error) 732 goto out_rg_gunlock; 733 734 down_write(&ip->i_rw_mutex); 735 736 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 737 gfs2_trans_add_bh(ip->i_gl, bh, 1); 738 739 bstart = 0; 740 blen = 0; 741 742 for (p = top; p < bottom; p++) { 743 if (!*p) 744 continue; 745 746 bn = be64_to_cpu(*p); 747 748 if (bstart + blen == bn) 749 blen++; 750 else { 751 if (bstart) { 752 if (metadata) 753 gfs2_free_meta(ip, bstart, blen); 754 else 755 gfs2_free_data(ip, bstart, blen); 756 } 757 758 bstart = bn; 759 blen = 1; 760 } 761 762 *p = 0; 763 if (!ip->i_di.di_blocks) 764 gfs2_consist_inode(ip); 765 ip->i_di.di_blocks--; 766 gfs2_set_inode_blocks(&ip->i_inode); 767 } 768 if (bstart) { 769 if (metadata) 770 gfs2_free_meta(ip, bstart, blen); 771 else 772 gfs2_free_data(ip, bstart, blen); 773 } 774 775 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC; 776 777 gfs2_dinode_out(ip, dibh->b_data); 778 779 up_write(&ip->i_rw_mutex); 780 781 gfs2_trans_end(sdp); 782 783out_rg_gunlock: 784 gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs); 785out_rlist: 786 gfs2_rlist_free(&rlist); 787out: 788 gfs2_glock_dq_uninit(&ip->i_alloc.al_ri_gh); 789 return error; 790} 791 792/** 793 * do_grow - Make a file look bigger than it is 794 * @ip: the inode 795 * @size: the size to set the file to 796 * 797 * Called with an exclusive lock on @ip. 798 * 799 * Returns: errno 800 */ 801 802static int do_grow(struct gfs2_inode *ip, u64 size) 803{ 804 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 805 struct gfs2_alloc *al; 806 struct buffer_head *dibh; 807 unsigned int h; 808 int error; 809 810 al = gfs2_alloc_get(ip); 811 812 error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); 813 if (error) 814 goto out; 815 816 error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid); 817 if (error) 818 goto out_gunlock_q; 819 820 al->al_requested = sdp->sd_max_height + RES_DATA; 821 822 error = gfs2_inplace_reserve(ip); 823 if (error) 824 goto out_gunlock_q; 825 826 error = gfs2_trans_begin(sdp, 827 sdp->sd_max_height + al->al_rgd->rd_ri.ri_length + 828 RES_JDATA + RES_DINODE + RES_STATFS + RES_QUOTA, 0); 829 if (error) 830 goto out_ipres; 831 832 if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { 833 if (gfs2_is_stuffed(ip)) { 834 error = gfs2_unstuff_dinode(ip, NULL); 835 if (error) 836 goto out_end_trans; 837 } 838 839 h = calc_tree_height(ip, size); 840 if (ip->i_di.di_height < h) { 841 down_write(&ip->i_rw_mutex); 842 error = build_height(&ip->i_inode, h); 843 up_write(&ip->i_rw_mutex); 844 if (error) 845 goto out_end_trans; 846 } 847 } 848 849 ip->i_di.di_size = size; 850 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC; 851 852 error = gfs2_meta_inode_buffer(ip, &dibh); 853 if (error) 854 goto out_end_trans; 855 856 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 857 gfs2_dinode_out(ip, dibh->b_data); 858 brelse(dibh); 859 860out_end_trans: 861 gfs2_trans_end(sdp); 862out_ipres: 863 gfs2_inplace_release(ip); 864out_gunlock_q: 865 gfs2_quota_unlock(ip); 866out: 867 gfs2_alloc_put(ip); 868 return error; 869} 870 871 872/** 873 * gfs2_block_truncate_page - Deal with zeroing out data for truncate 874 * 875 * This is partly borrowed from ext3. 876 */ 877static int gfs2_block_truncate_page(struct address_space *mapping) 878{ 879 struct inode *inode = mapping->host; 880 struct gfs2_inode *ip = GFS2_I(inode); 881 struct gfs2_sbd *sdp = GFS2_SB(inode); 882 loff_t from = inode->i_size; 883 unsigned long index = from >> PAGE_CACHE_SHIFT; 884 unsigned offset = from & (PAGE_CACHE_SIZE-1); 885 unsigned blocksize, iblock, length, pos; 886 struct buffer_head *bh; 887 struct page *page; 888 void *kaddr; 889 int err; 890 891 page = grab_cache_page(mapping, index); 892 if (!page) 893 return 0; 894 895 blocksize = inode->i_sb->s_blocksize; 896 length = blocksize - (offset & (blocksize - 1)); 897 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); 898 899 if (!page_has_buffers(page)) 900 create_empty_buffers(page, blocksize, 0); 901 902 /* Find the buffer that contains "offset" */ 903 bh = page_buffers(page); 904 pos = blocksize; 905 while (offset >= pos) { 906 bh = bh->b_this_page; 907 iblock++; 908 pos += blocksize; 909 } 910 911 err = 0; 912 913 if (!buffer_mapped(bh)) { 914 gfs2_get_block(inode, iblock, bh, 0); 915 /* unmapped? It's a hole - nothing to do */ 916 if (!buffer_mapped(bh)) 917 goto unlock; 918 } 919 920 /* Ok, it's mapped. Make sure it's up-to-date */ 921 if (PageUptodate(page)) 922 set_buffer_uptodate(bh); 923 924 if (!buffer_uptodate(bh)) { 925 err = -EIO; 926 ll_rw_block(READ, 1, &bh); 927 wait_on_buffer(bh); 928 /* Uhhuh. Read error. Complain and punt. */ 929 if (!buffer_uptodate(bh)) 930 goto unlock; 931 } 932 933 if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) 934 gfs2_trans_add_bh(ip->i_gl, bh, 0); 935 936 kaddr = kmap_atomic(page, KM_USER0); 937 memset(kaddr + offset, 0, length); 938 flush_dcache_page(page); 939 kunmap_atomic(kaddr, KM_USER0); 940 941unlock: 942 unlock_page(page); 943 page_cache_release(page); 944 return err; 945} 946 947static int trunc_start(struct gfs2_inode *ip, u64 size) 948{ 949 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 950 struct buffer_head *dibh; 951 int journaled = gfs2_is_jdata(ip); 952 int error; 953 954 error = gfs2_trans_begin(sdp, 955 RES_DINODE + (journaled ? RES_JDATA : 0), 0); 956 if (error) 957 return error; 958 959 error = gfs2_meta_inode_buffer(ip, &dibh); 960 if (error) 961 goto out; 962 963 if (gfs2_is_stuffed(ip)) { 964 ip->i_di.di_size = size; 965 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC; 966 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 967 gfs2_dinode_out(ip, dibh->b_data); 968 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + size); 969 error = 1; 970 971 } else { 972 if (size & (u64)(sdp->sd_sb.sb_bsize - 1)) 973 error = gfs2_block_truncate_page(ip->i_inode.i_mapping); 974 975 if (!error) { 976 ip->i_di.di_size = size; 977 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC; 978 ip->i_di.di_flags |= GFS2_DIF_TRUNC_IN_PROG; 979 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 980 gfs2_dinode_out(ip, dibh->b_data); 981 } 982 } 983 984 brelse(dibh); 985 986out: 987 gfs2_trans_end(sdp); 988 return error; 989} 990 991static int trunc_dealloc(struct gfs2_inode *ip, u64 size) 992{ 993 unsigned int height = ip->i_di.di_height; 994 u64 lblock; 995 struct metapath mp; 996 int error; 997 998 if (!size) 999 lblock = 0; 1000 else 1001 lblock = (size - 1) >> GFS2_SB(&ip->i_inode)->sd_sb.sb_bsize_shift; 1002 1003 find_metapath(ip, lblock, &mp); 1004 gfs2_alloc_get(ip); 1005 1006 error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); 1007 if (error) 1008 goto out; 1009 1010 while (height--) { 1011 struct strip_mine sm; 1012 sm.sm_first = !!size; 1013 sm.sm_height = height; 1014 1015 error = recursive_scan(ip, NULL, &mp, 0, 0, 1, do_strip, &sm); 1016 if (error) 1017 break; 1018 } 1019 1020 gfs2_quota_unhold(ip); 1021 1022out: 1023 gfs2_alloc_put(ip); 1024 return error; 1025} 1026 1027static int trunc_end(struct gfs2_inode *ip) 1028{ 1029 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 1030 struct buffer_head *dibh; 1031 int error; 1032 1033 error = gfs2_trans_begin(sdp, RES_DINODE, 0); 1034 if (error) 1035 return error; 1036 1037 down_write(&ip->i_rw_mutex); 1038 1039 error = gfs2_meta_inode_buffer(ip, &dibh); 1040 if (error) 1041 goto out; 1042 1043 if (!ip->i_di.di_size) { 1044 ip->i_di.di_height = 0; 1045 ip->i_di.di_goal_meta = 1046 ip->i_di.di_goal_data = 1047 ip->i_num.no_addr; 1048 gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); 1049 } 1050 ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME_SEC; 1051 ip->i_di.di_flags &= ~GFS2_DIF_TRUNC_IN_PROG; 1052 1053 gfs2_trans_add_bh(ip->i_gl, dibh, 1); 1054 gfs2_dinode_out(ip, dibh->b_data); 1055 brelse(dibh); 1056 1057out: 1058 up_write(&ip->i_rw_mutex); 1059 gfs2_trans_end(sdp); 1060 return error; 1061} 1062 1063/** 1064 * do_shrink - make a file smaller 1065 * @ip: the inode 1066 * @size: the size to make the file 1067 * @truncator: function to truncate the last partial block 1068 * 1069 * Called with an exclusive lock on @ip. 1070 * 1071 * Returns: errno 1072 */ 1073 1074static int do_shrink(struct gfs2_inode *ip, u64 size) 1075{ 1076 int error; 1077 1078 error = trunc_start(ip, size); 1079 if (error < 0) 1080 return error; 1081 if (error > 0) 1082 return 0; 1083 1084 error = trunc_dealloc(ip, size); 1085 if (!error) 1086 error = trunc_end(ip); 1087 1088 return error; 1089} 1090 1091/** 1092 * gfs2_truncatei - make a file a given size 1093 * @ip: the inode 1094 * @size: the size to make the file 1095 * @truncator: function to truncate the last partial block 1096 * 1097 * The file size can grow, shrink, or stay the same size. 1098 * 1099 * Returns: errno 1100 */ 1101 1102int gfs2_truncatei(struct gfs2_inode *ip, u64 size) 1103{ 1104 int error; 1105 1106 if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), S_ISREG(ip->i_inode.i_mode))) 1107 return -EINVAL; 1108 1109 if (size > ip->i_di.di_size) 1110 error = do_grow(ip, size); 1111 else 1112 error = do_shrink(ip, size); 1113 1114 return error; 1115} 1116 1117int gfs2_truncatei_resume(struct gfs2_inode *ip) 1118{ 1119 int error; 1120 error = trunc_dealloc(ip, ip->i_di.di_size); 1121 if (!error) 1122 error = trunc_end(ip); 1123 return error; 1124} 1125 1126int gfs2_file_dealloc(struct gfs2_inode *ip) 1127{ 1128 return trunc_dealloc(ip, 0); 1129} 1130 1131/** 1132 * gfs2_write_calc_reserv - calculate number of blocks needed to write to a file 1133 * @ip: the file 1134 * @len: the number of bytes to be written to the file 1135 * @data_blocks: returns the number of data blocks required 1136 * @ind_blocks: returns the number of indirect blocks required 1137 * 1138 */ 1139 1140void gfs2_write_calc_reserv(struct gfs2_inode *ip, unsigned int len, 1141 unsigned int *data_blocks, unsigned int *ind_blocks) 1142{ 1143 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 1144 unsigned int tmp; 1145 1146 if (gfs2_is_dir(ip)) { 1147 *data_blocks = DIV_ROUND_UP(len, sdp->sd_jbsize) + 2; 1148 *ind_blocks = 3 * (sdp->sd_max_jheight - 1); 1149 } else { 1150 *data_blocks = (len >> sdp->sd_sb.sb_bsize_shift) + 3; 1151 *ind_blocks = 3 * (sdp->sd_max_height - 1); 1152 } 1153 1154 for (tmp = *data_blocks; tmp > sdp->sd_diptrs;) { 1155 tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs); 1156 *ind_blocks += tmp; 1157 } 1158} 1159 1160/** 1161 * gfs2_write_alloc_required - figure out if a write will require an allocation 1162 * @ip: the file being written to 1163 * @offset: the offset to write to 1164 * @len: the number of bytes being written 1165 * @alloc_required: set to 1 if an alloc is required, 0 otherwise 1166 * 1167 * Returns: errno 1168 */ 1169 1170int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, 1171 unsigned int len, int *alloc_required) 1172{ 1173 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 1174 u64 lblock, lblock_stop, dblock; 1175 u32 extlen; 1176 int new = 0; 1177 int error = 0; 1178 1179 *alloc_required = 0; 1180 1181 if (!len) 1182 return 0; 1183 1184 if (gfs2_is_stuffed(ip)) { 1185 if (offset + len > 1186 sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) 1187 *alloc_required = 1; 1188 return 0; 1189 } 1190 1191 if (gfs2_is_dir(ip)) { 1192 unsigned int bsize = sdp->sd_jbsize; 1193 lblock = offset; 1194 do_div(lblock, bsize); 1195 lblock_stop = offset + len + bsize - 1; 1196 do_div(lblock_stop, bsize); 1197 } else { 1198 unsigned int shift = sdp->sd_sb.sb_bsize_shift; 1199 lblock = offset >> shift; 1200 lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift; 1201 } 1202 1203 for (; lblock < lblock_stop; lblock += extlen) { 1204 error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, &extlen); 1205 if (error) 1206 return error; 1207 1208 if (!dblock) { 1209 *alloc_required = 1; 1210 return 0; 1211 } 1212 } 1213 1214 return 0; 1215} 1216