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         if (atomic_dec_and_test(&entry->refs))
 249                 kfree(entry);
 250         return 0;
 251 }
 252
 253 int btrfs_remove_ordered_extent(struct inode *inode,
 254                                 struct btrfs_ordered_extent *entry)
 255 {
 256         struct btrfs_ordered_inode_tree *tree;
 257         struct rb_node *node;
 258
 259         tree = &BTRFS_I(inode)->ordered_tree;
 260         mutex_lock(&tree->mutex);
 261         node = &entry->rb_node;
 262         rb_erase(node, &tree->tree);
 263         tree->last = NULL;
 264         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 265         mutex_unlock(&tree->mutex);
 266         wake_up(&entry->wait);
 267         return 0;
 268 }
 269
 270 void btrfs_wait_ordered_extent(struct inode *inode,
 271                                struct btrfs_ordered_extent *entry)
 272 {
 273         u64 start = entry->file_offset;
 274         u64 end = start + entry->len - 1;
 275 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
 276         do_sync_file_range(file, start, end, SYNC_FILE_RANGE_WRITE);
 277 #else
 278         do_sync_mapping_range(inode->i_mapping, start, end,
 279                               SYNC_FILE_RANGE_WRITE);
 280 #endif
 281         wait_event(entry->wait,
 282                    test_bit(BTRFS_ORDERED_COMPLETE, &entry->flags));
 283 }
 284
 285 static void btrfs_start_ordered_extent(struct inode *inode,
 286                                struct btrfs_ordered_extent *entry, int wait)
 287 {
 288         u64 start = entry->file_offset;
 289         u64 end = start + entry->len - 1;
 290
 291 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
 292         do_sync_file_range(file, start, end, SYNC_FILE_RANGE_WRITE);
 293 #else
 294         do_sync_mapping_range(inode->i_mapping, start, end,
 295                               SYNC_FILE_RANGE_WRITE);
 296 #endif
 297         if (wait)
 298                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 299                                                  &entry->flags));
 300 }
 301
 302 void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 303 {
 304         u64 end;
 305         struct btrfs_ordered_extent *ordered;
 306         int found;
 307         int should_wait = 0;
 308
 309 again:
 310         if (start + len < start)
 311                 end = (u64)-1;
 312         else
 313                 end = start + len - 1;
 314         found = 0;
 315         while(1) {
 316                 ordered = btrfs_lookup_first_ordered_extent(inode, end);
 317                 if (!ordered) {
 318                         break;
 319                 }
 320                 if (ordered->file_offset >= start + len) {
 321                         btrfs_put_ordered_extent(ordered);
 322                         break;
 323                 }
 324                 if (ordered->file_offset + ordered->len < start) {
 325                         btrfs_put_ordered_extent(ordered);
 326                         break;
 327                 }
 328                 btrfs_start_ordered_extent(inode, ordered, should_wait);
 329                 found++;
 330                 end = ordered->file_offset;
 331                 btrfs_put_ordered_extent(ordered);
 332                 if (end == 0)
 333                         break;
 334                 end--;
 335         }
 336         if (should_wait && found) {
 337                 should_wait = 0;
 338                 goto again;
 339         }
 340 }
 341
 342 int btrfs_add_ordered_pending(struct inode *inode,
 343                               struct btrfs_ordered_extent *ordered,
 344                               u64 start, u64 len)
 345 {
 346         WARN_ON(1);
 347         return 0;
 348 #if 0
 349         int ret;
 350         struct btrfs_ordered_inode_tree *tree;
 351         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 352
 353         tree = &BTRFS_I(inode)->ordered_tree;
 354         mutex_lock(&tree->mutex);
 355         if (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)) {
 356                 ret = -EAGAIN;
 357                 goto out;
 358         }
 359         set_extent_ordered(io_tree, start, start + len - 1, GFP_NOFS);
 360         ret = 0;
 361 out:
 362         mutex_unlock(&tree->mutex);
 363         return ret;
 364 #endif
 365 }
 366
 367 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 368                                                          u64 file_offset)
 369 {
 370         struct btrfs_ordered_inode_tree *tree;
 371         struct rb_node *node;
 372         struct btrfs_ordered_extent *entry = NULL;
 373
 374         tree = &BTRFS_I(inode)->ordered_tree;
 375         mutex_lock(&tree->mutex);
 376         node = tree_search(tree, file_offset);
 377         if (!node)
 378                 goto out;
 379
 380         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 381         if (!offset_in_entry(entry, file_offset))
 382                 entry = NULL;
 383         if (entry)
 384                 atomic_inc(&entry->refs);
 385 out:
 386         mutex_unlock(&tree->mutex);
 387         return entry;
 388 }
 389
 390 struct btrfs_ordered_extent *
 391 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset)
 392 {
 393         struct btrfs_ordered_inode_tree *tree;
 394         struct rb_node *node;
 395         struct btrfs_ordered_extent *entry = NULL;
 396
 397         tree = &BTRFS_I(inode)->ordered_tree;
 398         mutex_lock(&tree->mutex);
 399         node = tree_search(tree, file_offset);
 400         if (!node)
 401                 goto out;
 402
 403         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 404         atomic_inc(&entry->refs);
 405 out:
 406         mutex_unlock(&tree->mutex);
 407         return entry;
 408 }