fs/btrfs/ordered-data.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/gfp.h>
  20 #include <linux/slab.h>
  21 #include <linux/blkdev.h>
  22 #include "ctree.h"
  23 #include "transaction.h"
  24 #include "btrfs_inode.h"
  25 #include "extent_io.h"
  26
  27
  28 static u64 entry_end(struct btrfs_ordered_extent *entry)
  29 {
  30         if (entry->file_offset + entry->len < entry->file_offset)
  31                 return (u64)-1;
  32         return entry->file_offset + entry->len;
  33 }
  34
  35 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  36                                    struct rb_node *node)
  37 {
  38         struct rb_node ** p = &root->rb_node;
  39         struct rb_node * parent = NULL;
  40         struct btrfs_ordered_extent *entry;
  41
  42         while(*p) {
  43                 parent = *p;
  44                 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  45
  46                 if (file_offset < entry->file_offset)
  47                         p = &(*p)->rb_left;
  48                 else if (file_offset >= entry_end(entry))
  49                         p = &(*p)->rb_right;
  50                 else
  51                         return parent;
  52         }
  53
  54         rb_link_node(node, parent, p);
  55         rb_insert_color(node, root);
  56         return NULL;
  57 }
  58
  59 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
  60                                      struct rb_node **prev_ret)
  61 {
  62         struct rb_node * n = root->rb_node;
  63         struct rb_node *prev = NULL;
  64         struct rb_node *test;
  65         struct btrfs_ordered_extent *entry;
  66         struct btrfs_ordered_extent *prev_entry = NULL;
  67
  68         while(n) {
  69                 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
  70                 prev = n;
  71                 prev_entry = entry;
  72
  73                 if (file_offset < entry->file_offset)
  74                         n = n->rb_left;
  75                 else if (file_offset >= entry_end(entry))
  76                         n = n->rb_right;
  77                 else
  78                         return n;
  79         }
  80         if (!prev_ret)
  81                 return NULL;
  82
  83         while(prev && file_offset >= entry_end(prev_entry)) {
  84                 test = rb_next(prev);
  85                 if (!test)
  86                         break;
  87                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
  88                                       rb_node);
  89                 if (file_offset < entry_end(prev_entry))
  90                         break;
  91
  92                 prev = test;
  93         }
  94         if (prev)
  95                 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
  96                                       rb_node);
  97         while(prev && file_offset < entry_end(prev_entry)) {
  98                 test = rb_prev(prev);
  99                 if (!test)
 100                         break;
 101                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 102                                       rb_node);
 103                 prev = test;
 104         }
 105         *prev_ret = prev;
 106         return NULL;
 107 }
 108
 109 static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
 110 {
 111         if (file_offset < entry->file_offset ||
 112             entry->file_offset + entry->len <= file_offset)
 113                 return 0;
 114         return 1;
 115 }
 116
 117 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 118                                           u64 file_offset)
 119 {
 120         struct rb_root *root = &tree->tree;
 121         struct rb_node *prev;
 122         struct rb_node *ret;
 123         struct btrfs_ordered_extent *entry;
 124
 125         if (tree->last) {
 126                 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
 127                                  rb_node);
 128                 if (offset_in_entry(entry, file_offset))
 129                         return tree->last;
 130         }
 131         ret = __tree_search(root, file_offset, &prev);
 132         if (!ret)
 133                 ret = prev;
 134         if (ret)
 135                 tree->last = ret;
 136         return ret;
 137 }
 138
 139 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 140                              u64 start, u64 len)
 141 {
 142         struct btrfs_ordered_inode_tree *tree;
 143         struct rb_node *node;
 144         struct btrfs_ordered_extent *entry;
 145
 146         tree = &BTRFS_I(inode)->ordered_tree;
 147         entry = kzalloc(sizeof(*entry), GFP_NOFS);
 148         if (!entry)
 149                 return -ENOMEM;
 150
 151         mutex_lock(&tree->mutex);
 152         entry->file_offset = file_offset;
 153         entry->start = start;
 154         entry->len = len;
 155         entry->inode = inode;
 156         /* one ref for the tree */
 157         atomic_set(&entry->refs, 1);
 158         init_waitqueue_head(&entry->wait);
 159         INIT_LIST_HEAD(&entry->list);
 160
 161         node = tree_insert(&tree->tree, file_offset,
 162                            &entry->rb_node);
 163         if (node) {
 164                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 165                 atomic_inc(&entry->refs);
 166         }
 167         set_extent_ordered(&BTRFS_I(inode)->io_tree, file_offset,
 168                            entry_end(entry) - 1, GFP_NOFS);
 169
 170         set_bit(BTRFS_ORDERED_START, &entry->flags);
 171         mutex_unlock(&tree->mutex);
 172         BUG_ON(node);
 173         return 0;
 174 }
 175
 176 int btrfs_add_ordered_sum(struct inode *inode, struct btrfs_ordered_sum *sum)
 177 {
 178         struct btrfs_ordered_inode_tree *tree;
 179         struct rb_node *node;
 180         struct btrfs_ordered_extent *entry;
 181
 182         tree = &BTRFS_I(inode)->ordered_tree;
 183         mutex_lock(&tree->mutex);
 184         node = tree_search(tree, sum->file_offset);
 185         if (!node) {
 186 search_fail:
 187 printk("add ordered sum failed to find a node for inode %lu offset %Lu\n", inode->i_ino, sum->file_offset);
 188                 node = rb_first(&tree->tree);
 189                 while(node) {
 190                         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 191                         printk("entry %Lu %Lu %Lu\n", entry->file_offset, entry->file_offset + entry->len, entry->start);
 192                         node = rb_next(node);
 193                 }
 194                 BUG();
 195         }
 196         BUG_ON(!node);
 197
 198         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 199         if (!offset_in_entry(entry, sum->file_offset)) {
 200                 goto search_fail;
 201         }
 202
 203         list_add_tail(&sum->list, &entry->list);
 204         mutex_unlock(&tree->mutex);
 205         return 0;
 206 }
 207
 208 int btrfs_dec_test_ordered_pending(struct inode *inode,
 209                                    u64 file_offset, u64 io_size)
 210 {
 211         struct btrfs_ordered_inode_tree *tree;
 212         struct rb_node *node;
 213         struct btrfs_ordered_extent *entry;
 214         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 215         int ret;
 216
 217         tree = &BTRFS_I(inode)->ordered_tree;
 218         mutex_lock(&tree->mutex);
 219         clear_extent_ordered(io_tree, file_offset, file_offset + io_size - 1,
 220                              GFP_NOFS);
 221         node = tree_search(tree, file_offset);
 222         if (!node) {
 223                 ret = 1;
 224                 goto out;
 225         }
 226
 227         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 228         if (!offset_in_entry(entry, file_offset)) {
 229                 ret = 1;
 230                 goto out;
 231         }
 232
 233         ret = test_range_bit(io_tree, entry->file_offset,
 234                              entry->file_offset + entry->len - 1,
 235                              EXTENT_ORDERED, 0);
 236         if (!test_bit(BTRFS_ORDERED_START, &entry->flags)) {
 237 printk("inode %lu not ready yet for extent %Lu %Lu\n", inode->i_ino, entry->file_offset, entry_end(entry));
 238         }
 239         if (ret == 0)
 240                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 241 out:
 242         mutex_unlock(&tree->mutex);
 243         return ret == 0;
 244 }
 245
 246 int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 247 {
 248         struct list_head *cur;
 249         struct btrfs_ordered_sum *sum;
 250
 251         if (atomic_dec_and_test(&entry->refs)) {
 252                 while(!list_empty(&entry->list)) {
 253                         cur = entry->list.next;
 254                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 255                         list_del(&sum->list);
 256                         kfree(sum);
 257                 }
 258                 kfree(entry);
 259         }
 260         return 0;
 261 }
 262
 263 int btrfs_remove_ordered_extent(struct inode *inode,
 264                                 struct btrfs_ordered_extent *entry)
 265 {
 266         struct btrfs_ordered_inode_tree *tree;
 267         struct rb_node *node;
 268
 269         tree = &BTRFS_I(inode)->ordered_tree;
 270         mutex_lock(&tree->mutex);
 271         node = &entry->rb_node;
 272         rb_erase(node, &tree->tree);
 273         tree->last = NULL;
 274         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 275         mutex_unlock(&tree->mutex);
 276         wake_up(&entry->wait);
 277         return 0;
 278 }
 279
 280 void btrfs_wait_ordered_extent(struct inode *inode,
 281                                struct btrfs_ordered_extent *entry)
 282 {
 283         u64 start = entry->file_offset;
 284         u64 end = start + entry->len - 1;
 285 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
 286         do_sync_file_range(file, start, end, SYNC_FILE_RANGE_WRITE);
 287 #else
 288         do_sync_mapping_range(inode->i_mapping, start, end,
 289                               SYNC_FILE_RANGE_WRITE);
 290 #endif
 291         wait_event(entry->wait,
 292                    test_bit(BTRFS_ORDERED_COMPLETE, &entry->flags));
 293 }
 294
 295 static void btrfs_start_ordered_extent(struct inode *inode,
 296                                struct btrfs_ordered_extent *entry, int wait)
 297 {
 298         u64 start = entry->file_offset;
 299         u64 end = start + entry->len - 1;
 300
 301 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
 302         do_sync_file_range(file, start, end, SYNC_FILE_RANGE_WRITE);
 303 #else
 304         do_sync_mapping_range(inode->i_mapping, start, end,
 305                               SYNC_FILE_RANGE_WRITE);
 306 #endif
 307         if (wait)
 308                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 309                                                  &entry->flags));
 310 }
 311
 312 void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 313 {
 314         u64 end;
 315         struct btrfs_ordered_extent *ordered;
 316         int found;
 317         int should_wait = 0;
 318
 319 again:
 320         if (start + len < start)
 321                 end = (u64)-1;
 322         else
 323                 end = start + len - 1;
 324         found = 0;
 325         while(1) {
 326                 ordered = btrfs_lookup_first_ordered_extent(inode, end);
 327                 if (!ordered) {
 328                         break;
 329                 }
 330                 if (ordered->file_offset >= start + len) {
 331                         btrfs_put_ordered_extent(ordered);
 332                         break;
 333                 }
 334                 if (ordered->file_offset + ordered->len < start) {
 335                         btrfs_put_ordered_extent(ordered);
 336                         break;
 337                 }
 338                 btrfs_start_ordered_extent(inode, ordered, should_wait);
 339                 found++;
 340                 end = ordered->file_offset;
 341                 btrfs_put_ordered_extent(ordered);
 342                 if (end == 0)
 343                         break;
 344                 end--;
 345         }
 346         if (should_wait && found) {
 347                 should_wait = 0;
 348                 goto again;
 349         }
 350 }
 351
 352 int btrfs_add_ordered_pending(struct inode *inode,
 353                               struct btrfs_ordered_extent *ordered,
 354                               u64 start, u64 len)
 355 {
 356         WARN_ON(1);
 357         return 0;
 358 #if 0
 359         int ret;
 360         struct btrfs_ordered_inode_tree *tree;
 361         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 362
 363         tree = &BTRFS_I(inode)->ordered_tree;
 364         mutex_lock(&tree->mutex);
 365         if (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)) {
 366                 ret = -EAGAIN;
 367                 goto out;
 368         }
 369         set_extent_ordered(io_tree, start, start + len - 1, GFP_NOFS);
 370         ret = 0;
 371 out:
 372         mutex_unlock(&tree->mutex);
 373         return ret;
 374 #endif
 375 }
 376
 377 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 378                                                          u64 file_offset)
 379 {
 380         struct btrfs_ordered_inode_tree *tree;
 381         struct rb_node *node;
 382         struct btrfs_ordered_extent *entry = NULL;
 383
 384         tree = &BTRFS_I(inode)->ordered_tree;
 385         mutex_lock(&tree->mutex);
 386         node = tree_search(tree, file_offset);
 387         if (!node)
 388                 goto out;
 389
 390         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 391         if (!offset_in_entry(entry, file_offset))
 392                 entry = NULL;
 393         if (entry)
 394                 atomic_inc(&entry->refs);
 395 out:
 396         mutex_unlock(&tree->mutex);
 397         return entry;
 398 }
 399
 400 struct btrfs_ordered_extent *
 401 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset)
 402 {
 403         struct btrfs_ordered_inode_tree *tree;
 404         struct rb_node *node;
 405         struct btrfs_ordered_extent *entry = NULL;
 406
 407         tree = &BTRFS_I(inode)->ordered_tree;
 408         mutex_lock(&tree->mutex);
 409         node = tree_search(tree, file_offset);
 410         if (!node)
 411                 goto out;
 412
 413         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 414         atomic_inc(&entry->refs);
 415 out:
 416         mutex_unlock(&tree->mutex);
 417         return entry;
 418 }
 419
 420 int btrfs_ordered_update_i_size(struct inode *inode,
 421                                 struct btrfs_ordered_extent *ordered)
 422 {
 423         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 424         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 425         u64 disk_i_size;
 426         u64 new_i_size;
 427         u64 i_size_test;
 428         struct rb_node *node;
 429         struct btrfs_ordered_extent *test;
 430
 431         mutex_lock(&tree->mutex);
 432         disk_i_size = BTRFS_I(inode)->disk_i_size;
 433
 434         /*
 435          * if the disk i_size is already at the inode->i_size, or
 436          * this ordered extent is inside the disk i_size, we're done
 437          */
 438         if (disk_i_size >= inode->i_size ||
 439             ordered->file_offset + ordered->len <= disk_i_size) {
 440                 goto out;
 441         }
 442
 443         /*
 444          * we can't update the disk_isize if there are delalloc bytes
 445          * between disk_i_size and  this ordered extent
 446          */
 447         if (test_range_bit(io_tree, disk_i_size,
 448                            ordered->file_offset + ordered->len - 1,
 449                            EXTENT_DELALLOC, 0)) {
 450                 goto out;
 451         }
 452         /*
 453          * walk backward from this ordered extent to disk_i_size.
 454          * if we find an ordered extent then we can't update disk i_size
 455          * yet
 456          */
 457         node = &ordered->rb_node;
 458         while(1) {
 459                 node = rb_prev(node);
 460                 if (!node)
 461                         break;
 462                 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 463                 if (test->file_offset + test->len <= disk_i_size)
 464                         break;
 465                 if (test->file_offset >= inode->i_size)
 466                         break;
 467                 if (test->file_offset >= disk_i_size)
 468                         goto out;
 469         }
 470         new_i_size = min_t(u64, entry_end(ordered), i_size_read(inode));
 471
 472         /*
 473          * at this point, we know we can safely update i_size to at least
 474          * the offset from this ordered extent.  But, we need to
 475          * walk forward and see if ios from higher up in the file have
 476          * finished.
 477          */
 478         node = rb_next(&ordered->rb_node);
 479         i_size_test = 0;
 480         if (node) {
 481                 /*
 482                  * do we have an area where IO might have finished
 483                  * between our ordered extent and the next one.
 484                  */
 485                 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 486                 if (test->file_offset > entry_end(ordered)) {
 487                         i_size_test = test->file_offset - 1;
 488                 }
 489         } else {
 490                 i_size_test = i_size_read(inode);
 491         }
 492
 493         /*
 494          * i_size_test is the end of a region after this ordered
 495          * extent where there are no ordered extents.  As long as there
 496          * are no delalloc bytes in this area, it is safe to update
 497          * disk_i_size to the end of the region.
 498          */
 499         if (i_size_test > entry_end(ordered) &&
 500             !test_range_bit(io_tree, entry_end(ordered), i_size_test,
 501                            EXTENT_DELALLOC, 0)) {
 502                 new_i_size = min_t(u64, i_size_test, i_size_read(inode));
 503         }
 504         BTRFS_I(inode)->disk_i_size = new_i_size;
 505 out:
 506         mutex_unlock(&tree->mutex);
 507         return 0;
 508 }
 509
 510 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u32 *sum)
 511 {
 512         struct btrfs_ordered_sum *ordered_sum;
 513         struct btrfs_sector_sum *sector_sums;
 514         struct btrfs_ordered_extent *ordered;
 515         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 516         struct list_head *cur;
 517         int ret = 1;
 518         int index;
 519
 520         ordered = btrfs_lookup_ordered_extent(inode, offset);
 521         if (!ordered)
 522                 return 1;
 523
 524         mutex_lock(&tree->mutex);
 525         list_for_each_prev(cur, &ordered->list) {
 526                 ordered_sum = list_entry(cur, struct btrfs_ordered_sum, list);
 527                 if (offset >= ordered_sum->file_offset &&
 528                     offset < ordered_sum->file_offset + ordered_sum->len) {
 529                         index = (offset - ordered_sum->file_offset) /
 530                                 BTRFS_I(inode)->root->sectorsize;;
 531                         sector_sums = &ordered_sum->sums;
 532                         *sum = sector_sums[index].sum;
 533                         ret = 0;
 534                         goto out;
 535                 }
 536         }
 537 out:
 538         mutex_unlock(&tree->mutex);
 539         return ret;
 540 }
 541