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btrfs-progs: Fix infinite loop of btrfs subvolumn sync
[btrfs-progs-unstable/devel.git] / volumes.c
blobca50f1ce3271e65cfe5370a30a3ec6f1e592447b
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 #include <stdio.h>
19 #include <stdlib.h>
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <uuid/uuid.h>
23 #include <fcntl.h>
24 #include <unistd.h>
25 #include "ctree.h"
26 #include "disk-io.h"
27 #include "transaction.h"
28 #include "print-tree.h"
29 #include "volumes.h"
30 #include "utils.h"
31
32 struct stripe {
33 struct btrfs_device *dev;
34 u64 physical;
35 };
36
37 static inline int nr_parity_stripes(struct map_lookup *map)
38 {
39 if (map->type & BTRFS_BLOCK_GROUP_RAID5)
40 return 1;
41 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
42 return 2;
43 else
44 return 0;
45 }
46
47 static inline int nr_data_stripes(struct map_lookup *map)
48 {
49 return map->num_stripes - nr_parity_stripes(map);
50 }
51
52 #define is_parity_stripe(x) ( ((x) == BTRFS_RAID5_P_STRIPE) || ((x) == BTRFS_RAID6_Q_STRIPE) )
53
54 static LIST_HEAD(fs_uuids);
55
56 static struct btrfs_device *__find_device(struct list_head *head, u64 devid,
57 u8 *uuid)
58 {
59 struct btrfs_device *dev;
60 struct list_head *cur;
61
62 list_for_each(cur, head) {
63 dev = list_entry(cur, struct btrfs_device, dev_list);
64 if (dev->devid == devid &&
65 !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE)) {
66 return dev;
67 }
68 }
69 return NULL;
70 }
71
72 static struct btrfs_fs_devices *find_fsid(u8 *fsid)
73 {
74 struct list_head *cur;
75 struct btrfs_fs_devices *fs_devices;
76
77 list_for_each(cur, &fs_uuids) {
78 fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
79 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
80 return fs_devices;
81 }
82 return NULL;
83 }
84
85 static int device_list_add(const char *path,
86 struct btrfs_super_block *disk_super,
87 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
88 {
89 struct btrfs_device *device;
90 struct btrfs_fs_devices *fs_devices;
91 u64 found_transid = btrfs_super_generation(disk_super);
92
93 fs_devices = find_fsid(disk_super->fsid);
94 if (!fs_devices) {
95 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
96 if (!fs_devices)
97 return -ENOMEM;
98 INIT_LIST_HEAD(&fs_devices->devices);
99 list_add(&fs_devices->list, &fs_uuids);
100 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
101 fs_devices->latest_devid = devid;
102 fs_devices->latest_trans = found_transid;
103 fs_devices->lowest_devid = (u64)-1;
104 device = NULL;
105 } else {
106 device = __find_device(&fs_devices->devices, devid,
107 disk_super->dev_item.uuid);
108 }
109 if (!device) {
110 device = kzalloc(sizeof(*device), GFP_NOFS);
111 if (!device) {
112 /* we can safely leave the fs_devices entry around */
113 return -ENOMEM;
114 }
115 device->fd = -1;
116 device->devid = devid;
117 device->generation = found_transid;
118 memcpy(device->uuid, disk_super->dev_item.uuid,
119 BTRFS_UUID_SIZE);
120 device->name = kstrdup(path, GFP_NOFS);
121 if (!device->name) {
122 kfree(device);
123 return -ENOMEM;
124 }
125 device->label = kstrdup(disk_super->label, GFP_NOFS);
126 if (!device->label) {
127 kfree(device->name);
128 kfree(device);
129 return -ENOMEM;
130 }
131 device->total_devs = btrfs_super_num_devices(disk_super);
132 device->super_bytes_used = btrfs_super_bytes_used(disk_super);
133 device->total_bytes =
134 btrfs_stack_device_total_bytes(&disk_super->dev_item);
135 device->bytes_used =
136 btrfs_stack_device_bytes_used(&disk_super->dev_item);
137 list_add(&device->dev_list, &fs_devices->devices);
138 device->fs_devices = fs_devices;
139 } else if (!device->name || strcmp(device->name, path)) {
140 char *name = strdup(path);
141 if (!name)
142 return -ENOMEM;
143 kfree(device->name);
144 device->name = name;
145 }
146
147
148 if (found_transid > fs_devices->latest_trans) {
149 fs_devices->latest_devid = devid;
150 fs_devices->latest_trans = found_transid;
151 }
152 if (fs_devices->lowest_devid > devid) {
153 fs_devices->lowest_devid = devid;
154 }
155 *fs_devices_ret = fs_devices;
156 return 0;
157 }
158
159 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
160 {
161 struct btrfs_fs_devices *seed_devices;
162 struct btrfs_device *device;
163
164 again:
165 while (!list_empty(&fs_devices->devices)) {
166 device = list_entry(fs_devices->devices.next,
167 struct btrfs_device, dev_list);
168 if (device->fd != -1) {
169 fsync(device->fd);
170 if (posix_fadvise(device->fd, 0, 0, POSIX_FADV_DONTNEED))
171 fprintf(stderr, "Warning, could not drop caches\n");
172 close(device->fd);
173 device->fd = -1;
174 }
175 device->writeable = 0;
176 list_del(&device->dev_list);
177 /* free the memory */
178 free(device->name);
179 free(device->label);
180 free(device);
181 }
182
183 seed_devices = fs_devices->seed;
184 fs_devices->seed = NULL;
185 if (seed_devices) {
186 struct btrfs_fs_devices *orig;
187
188 orig = fs_devices;
189 fs_devices = seed_devices;
190 list_del(&orig->list);
191 free(orig);
192 goto again;
193 } else {
194 list_del(&fs_devices->list);
195 free(fs_devices);
196 }
197
198 return 0;
199 }
200
201 void btrfs_close_all_devices(void)
202 {
203 struct btrfs_fs_devices *fs_devices;
204
205 while (!list_empty(&fs_uuids)) {
206 fs_devices = list_entry(fs_uuids.next, struct btrfs_fs_devices,
207 list);
208 btrfs_close_devices(fs_devices);
209 }
210 }
211
212 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
213 {
214 int fd;
215 struct list_head *head = &fs_devices->devices;
216 struct list_head *cur;
217 struct btrfs_device *device;
218 int ret;
219
220 list_for_each(cur, head) {
221 device = list_entry(cur, struct btrfs_device, dev_list);
222 if (!device->name) {
223 printk("no name for device %llu, skip it now\n", device->devid);
224 continue;
225 }
226
227 fd = open(device->name, flags);
228 if (fd < 0) {
229 ret = -errno;
230 goto fail;
231 }
232
233 if (posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED))
234 fprintf(stderr, "Warning, could not drop caches\n");
235
236 if (device->devid == fs_devices->latest_devid)
237 fs_devices->latest_bdev = fd;
238 if (device->devid == fs_devices->lowest_devid)
239 fs_devices->lowest_bdev = fd;
240 device->fd = fd;
241 if (flags & O_RDWR)
242 device->writeable = 1;
243 }
244 return 0;
245 fail:
246 btrfs_close_devices(fs_devices);
247 return ret;
248 }
249
250 int btrfs_scan_one_device(int fd, const char *path,
251 struct btrfs_fs_devices **fs_devices_ret,
252 u64 *total_devs, u64 super_offset, int super_recover)
253 {
254 struct btrfs_super_block *disk_super;
255 char *buf;
256 int ret;
257 u64 devid;
258
259 buf = malloc(4096);
260 if (!buf) {
261 ret = -ENOMEM;
262 goto error;
263 }
264 disk_super = (struct btrfs_super_block *)buf;
265 ret = btrfs_read_dev_super(fd, disk_super, super_offset, super_recover);
266 if (ret < 0) {
267 ret = -EIO;
268 goto error_brelse;
269 }
270 devid = btrfs_stack_device_id(&disk_super->dev_item);
271 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)
272 *total_devs = 1;
273 else
274 *total_devs = btrfs_super_num_devices(disk_super);
275
276 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
277
278 error_brelse:
279 free(buf);
280 error:
281 return ret;
282 }
283
284 /*
285 * this uses a pretty simple search, the expectation is that it is
286 * called very infrequently and that a given device has a small number
287 * of extents
288 */
289 static int find_free_dev_extent(struct btrfs_trans_handle *trans,
290 struct btrfs_device *device,
291 struct btrfs_path *path,
292 u64 num_bytes, u64 *start)
293 {
294 struct btrfs_key key;
295 struct btrfs_root *root = device->dev_root;
296 struct btrfs_dev_extent *dev_extent = NULL;
297 u64 hole_size = 0;
298 u64 last_byte = 0;
299 u64 search_start = root->fs_info->alloc_start;
300 u64 search_end = device->total_bytes;
301 int ret;
302 int slot = 0;
303 int start_found;
304 struct extent_buffer *l;
305
306 start_found = 0;
307 path->reada = 2;
308
309 /* FIXME use last free of some kind */
310
311 /* we don't want to overwrite the superblock on the drive,
312 * so we make sure to start at an offset of at least 1MB
313 */
314 search_start = max(BTRFS_BLOCK_RESERVED_1M_FOR_SUPER, search_start);
315
316 if (search_start >= search_end) {
317 ret = -ENOSPC;
318 goto error;
319 }
320
321 key.objectid = device->devid;
322 key.offset = search_start;
323 key.type = BTRFS_DEV_EXTENT_KEY;
324 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
325 if (ret < 0)
326 goto error;
327 ret = btrfs_previous_item(root, path, 0, key.type);
328 if (ret < 0)
329 goto error;
330 l = path->nodes[0];
331 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
332 while (1) {
333 l = path->nodes[0];
334 slot = path->slots[0];
335 if (slot >= btrfs_header_nritems(l)) {
336 ret = btrfs_next_leaf(root, path);
337 if (ret == 0)
338 continue;
339 if (ret < 0)
340 goto error;
341 no_more_items:
342 if (!start_found) {
343 if (search_start >= search_end) {
344 ret = -ENOSPC;
345 goto error;
346 }
347 *start = search_start;
348 start_found = 1;
349 goto check_pending;
350 }
351 *start = last_byte > search_start ?
352 last_byte : search_start;
353 if (search_end <= *start) {
354 ret = -ENOSPC;
355 goto error;
356 }
357 goto check_pending;
358 }
359 btrfs_item_key_to_cpu(l, &key, slot);
360
361 if (key.objectid < device->devid)
362 goto next;
363
364 if (key.objectid > device->devid)
365 goto no_more_items;
366
367 if (key.offset >= search_start && key.offset > last_byte &&
368 start_found) {
369 if (last_byte < search_start)
370 last_byte = search_start;
371 hole_size = key.offset - last_byte;
372 if (key.offset > last_byte &&
373 hole_size >= num_bytes) {
374 *start = last_byte;
375 goto check_pending;
376 }
377 }
378 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
379 goto next;
380 }
381
382 start_found = 1;
383 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
384 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
385 next:
386 path->slots[0]++;
387 cond_resched();
388 }
389 check_pending:
390 /* we have to make sure we didn't find an extent that has already
391 * been allocated by the map tree or the original allocation
392 */
393 btrfs_release_path(path);
394 BUG_ON(*start < search_start);
395
396 if (*start + num_bytes > search_end) {
397 ret = -ENOSPC;
398 goto error;
399 }
400 /* check for pending inserts here */
401 return 0;
402
403 error:
404 btrfs_release_path(path);
405 return ret;
406 }
407
408 static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
409 struct btrfs_device *device,
410 u64 chunk_tree, u64 chunk_objectid,
411 u64 chunk_offset,
412 u64 num_bytes, u64 *start)
413 {
414 int ret;
415 struct btrfs_path *path;
416 struct btrfs_root *root = device->dev_root;
417 struct btrfs_dev_extent *extent;
418 struct extent_buffer *leaf;
419 struct btrfs_key key;
420
421 path = btrfs_alloc_path();
422 if (!path)
423 return -ENOMEM;
424
425 ret = find_free_dev_extent(trans, device, path, num_bytes, start);
426 if (ret) {
427 goto err;
428 }
429
430 key.objectid = device->devid;
431 key.offset = *start;
432 key.type = BTRFS_DEV_EXTENT_KEY;
433 ret = btrfs_insert_empty_item(trans, root, path, &key,
434 sizeof(*extent));
435 BUG_ON(ret);
436
437 leaf = path->nodes[0];
438 extent = btrfs_item_ptr(leaf, path->slots[0],
439 struct btrfs_dev_extent);
440 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
441 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
442 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
443
444 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
445 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
446 BTRFS_UUID_SIZE);
447
448 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
449 btrfs_mark_buffer_dirty(leaf);
450 err:
451 btrfs_free_path(path);
452 return ret;
453 }
454
455 static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset)
456 {
457 struct btrfs_path *path;
458 int ret;
459 struct btrfs_key key;
460 struct btrfs_chunk *chunk;
461 struct btrfs_key found_key;
462
463 path = btrfs_alloc_path();
464 BUG_ON(!path);
465
466 key.objectid = objectid;
467 key.offset = (u64)-1;
468 key.type = BTRFS_CHUNK_ITEM_KEY;
469
470 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
471 if (ret < 0)
472 goto error;
473
474 BUG_ON(ret == 0);
475
476 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
477 if (ret) {
478 *offset = 0;
479 } else {
480 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
481 path->slots[0]);
482 if (found_key.objectid != objectid)
483 *offset = 0;
484 else {
485 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
486 struct btrfs_chunk);
487 *offset = found_key.offset +
488 btrfs_chunk_length(path->nodes[0], chunk);
489 }
490 }
491 ret = 0;
492 error:
493 btrfs_free_path(path);
494 return ret;
495 }
496
497 static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
498 u64 *objectid)
499 {
500 int ret;
501 struct btrfs_key key;
502 struct btrfs_key found_key;
503
504 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
505 key.type = BTRFS_DEV_ITEM_KEY;
506 key.offset = (u64)-1;
507
508 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
509 if (ret < 0)
510 goto error;
511
512 BUG_ON(ret == 0);
513
514 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
515 BTRFS_DEV_ITEM_KEY);
516 if (ret) {
517 *objectid = 1;
518 } else {
519 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
520 path->slots[0]);
521 *objectid = found_key.offset + 1;
522 }
523 ret = 0;
524 error:
525 btrfs_release_path(path);
526 return ret;
527 }
528
529 /*
530 * the device information is stored in the chunk root
531 * the btrfs_device struct should be fully filled in
532 */
533 int btrfs_add_device(struct btrfs_trans_handle *trans,
534 struct btrfs_root *root,
535 struct btrfs_device *device)
536 {
537 int ret;
538 struct btrfs_path *path;
539 struct btrfs_dev_item *dev_item;
540 struct extent_buffer *leaf;
541 struct btrfs_key key;
542 unsigned long ptr;
543 u64 free_devid = 0;
544
545 root = root->fs_info->chunk_root;
546
547 path = btrfs_alloc_path();
548 if (!path)
549 return -ENOMEM;
550
551 ret = find_next_devid(root, path, &free_devid);
552 if (ret)
553 goto out;
554
555 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
556 key.type = BTRFS_DEV_ITEM_KEY;
557 key.offset = free_devid;
558
559 ret = btrfs_insert_empty_item(trans, root, path, &key,
560 sizeof(*dev_item));
561 if (ret)
562 goto out;
563
564 leaf = path->nodes[0];
565 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
566
567 device->devid = free_devid;
568 btrfs_set_device_id(leaf, dev_item, device->devid);
569 btrfs_set_device_generation(leaf, dev_item, 0);
570 btrfs_set_device_type(leaf, dev_item, device->type);
571 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
572 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
573 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
574 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
575 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
576 btrfs_set_device_group(leaf, dev_item, 0);
577 btrfs_set_device_seek_speed(leaf, dev_item, 0);
578 btrfs_set_device_bandwidth(leaf, dev_item, 0);
579 btrfs_set_device_start_offset(leaf, dev_item, 0);
580
581 ptr = (unsigned long)btrfs_device_uuid(dev_item);
582 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
583 ptr = (unsigned long)btrfs_device_fsid(dev_item);
584 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
585 btrfs_mark_buffer_dirty(leaf);
586 ret = 0;
587
588 out:
589 btrfs_free_path(path);
590 return ret;
591 }
592
593 int btrfs_update_device(struct btrfs_trans_handle *trans,
594 struct btrfs_device *device)
595 {
596 int ret;
597 struct btrfs_path *path;
598 struct btrfs_root *root;
599 struct btrfs_dev_item *dev_item;
600 struct extent_buffer *leaf;
601 struct btrfs_key key;
602
603 root = device->dev_root->fs_info->chunk_root;
604
605 path = btrfs_alloc_path();
606 if (!path)
607 return -ENOMEM;
608
609 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
610 key.type = BTRFS_DEV_ITEM_KEY;
611 key.offset = device->devid;
612
613 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
614 if (ret < 0)
615 goto out;
616
617 if (ret > 0) {
618 ret = -ENOENT;
619 goto out;
620 }
621
622 leaf = path->nodes[0];
623 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
624
625 btrfs_set_device_id(leaf, dev_item, device->devid);
626 btrfs_set_device_type(leaf, dev_item, device->type);
627 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
628 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
629 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
630 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
631 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
632 btrfs_mark_buffer_dirty(leaf);
633
634 out:
635 btrfs_free_path(path);
636 return ret;
637 }
638
639 int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
640 struct btrfs_root *root,
641 struct btrfs_key *key,
642 struct btrfs_chunk *chunk, int item_size)
643 {
644 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
645 struct btrfs_disk_key disk_key;
646 u32 array_size;
647 u8 *ptr;
648
649 array_size = btrfs_super_sys_array_size(super_copy);
650 if (array_size + item_size + sizeof(disk_key)
651 > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
652 return -EFBIG;
653
654 ptr = super_copy->sys_chunk_array + array_size;
655 btrfs_cpu_key_to_disk(&disk_key, key);
656 memcpy(ptr, &disk_key, sizeof(disk_key));
657 ptr += sizeof(disk_key);
658 memcpy(ptr, chunk, item_size);
659 item_size += sizeof(disk_key);
660 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
661 return 0;
662 }
663
664 static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
665 int sub_stripes)
666 {
667 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
668 return calc_size;
669 else if (type & BTRFS_BLOCK_GROUP_RAID10)
670 return calc_size * (num_stripes / sub_stripes);
671 else if (type & BTRFS_BLOCK_GROUP_RAID5)
672 return calc_size * (num_stripes - 1);
673 else if (type & BTRFS_BLOCK_GROUP_RAID6)
674 return calc_size * (num_stripes - 2);
675 else
676 return calc_size * num_stripes;
677 }
678
679
680 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
681 {
682 /* TODO, add a way to store the preferred stripe size */
683 return BTRFS_STRIPE_LEN;
684 }
685
686 /*
687 * btrfs_device_avail_bytes - count bytes available for alloc_chunk
688 *
689 * It is not equal to "device->total_bytes - device->bytes_used".
690 * We do not allocate any chunk in 1M at beginning of device, and not
691 * allowed to allocate any chunk before alloc_start if it is specified.
692 * So search holes from max(1M, alloc_start) to device->total_bytes.
693 */
694 static int btrfs_device_avail_bytes(struct btrfs_trans_handle *trans,
695 struct btrfs_device *device,
696 u64 *avail_bytes)
697 {
698 struct btrfs_path *path;
699 struct btrfs_root *root = device->dev_root;
700 struct btrfs_key key;
701 struct btrfs_dev_extent *dev_extent = NULL;
702 struct extent_buffer *l;
703 u64 search_start = root->fs_info->alloc_start;
704 u64 search_end = device->total_bytes;
705 u64 extent_end = 0;
706 u64 free_bytes = 0;
707 int ret;
708 int slot = 0;
709
710 search_start = max(BTRFS_BLOCK_RESERVED_1M_FOR_SUPER, search_start);
711
712 path = btrfs_alloc_path();
713 if (!path)
714 return -ENOMEM;
715
716 key.objectid = device->devid;
717 key.offset = root->fs_info->alloc_start;
718 key.type = BTRFS_DEV_EXTENT_KEY;
719
720 path->reada = 2;
721 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
722 if (ret < 0)
723 goto error;
724 ret = btrfs_previous_item(root, path, 0, key.type);
725 if (ret < 0)
726 goto error;
727
728 while (1) {
729 l = path->nodes[0];
730 slot = path->slots[0];
731 if (slot >= btrfs_header_nritems(l)) {
732 ret = btrfs_next_leaf(root, path);
733 if (ret == 0)
734 continue;
735 if (ret < 0)
736 goto error;
737 break;
738 }
739 btrfs_item_key_to_cpu(l, &key, slot);
740
741 if (key.objectid < device->devid)
742 goto next;
743 if (key.objectid > device->devid)
744 break;
745 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
746 goto next;
747 if (key.offset > search_end)
748 break;
749 if (key.offset > search_start)
750 free_bytes += key.offset - search_start;
751
752 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
753 extent_end = key.offset + btrfs_dev_extent_length(l,
754 dev_extent);
755 if (extent_end > search_start)
756 search_start = extent_end;
757 if (search_start > search_end)
758 break;
759 next:
760 path->slots[0]++;
761 cond_resched();
762 }
763
764 if (search_start < search_end)
765 free_bytes += search_end - search_start;
766
767 *avail_bytes = free_bytes;
768 ret = 0;
769 error:
770 btrfs_free_path(path);
771 return ret;
772 }
773
774 #define BTRFS_MAX_DEVS(r) ((BTRFS_LEAF_DATA_SIZE(r) \
775 - sizeof(struct btrfs_item) \
776 - sizeof(struct btrfs_chunk)) \
777 / sizeof(struct btrfs_stripe) + 1)
778
779 #define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE \
780 - 2 * sizeof(struct btrfs_disk_key) \
781 - 2 * sizeof(struct btrfs_chunk)) \
782 / sizeof(struct btrfs_stripe) + 1)
783
784 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
785 struct btrfs_root *extent_root, u64 *start,
786 u64 *num_bytes, u64 type)
787 {
788 u64 dev_offset;
789 struct btrfs_fs_info *info = extent_root->fs_info;
790 struct btrfs_root *chunk_root = info->chunk_root;
791 struct btrfs_stripe *stripes;
792 struct btrfs_device *device = NULL;
793 struct btrfs_chunk *chunk;
794 struct list_head private_devs;
795 struct list_head *dev_list = &info->fs_devices->devices;
796 struct list_head *cur;
797 struct map_lookup *map;
798 int min_stripe_size = 1 * 1024 * 1024;
799 u64 calc_size = 8 * 1024 * 1024;
800 u64 min_free;
801 u64 max_chunk_size = 4 * calc_size;
802 u64 avail = 0;
803 u64 max_avail = 0;
804 u64 percent_max;
805 int num_stripes = 1;
806 int max_stripes = 0;
807 int min_stripes = 1;
808 int sub_stripes = 0;
809 int looped = 0;
810 int ret;
811 int index;
812 int stripe_len = BTRFS_STRIPE_LEN;
813 struct btrfs_key key;
814 u64 offset;
815
816 if (list_empty(dev_list)) {
817 return -ENOSPC;
818 }
819
820 if (type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
821 BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
822 BTRFS_BLOCK_GROUP_RAID10 |
823 BTRFS_BLOCK_GROUP_DUP)) {
824 if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
825 calc_size = 8 * 1024 * 1024;
826 max_chunk_size = calc_size * 2;
827 min_stripe_size = 1 * 1024 * 1024;
828 max_stripes = BTRFS_MAX_DEVS_SYS_CHUNK;
829 } else if (type & BTRFS_BLOCK_GROUP_DATA) {
830 calc_size = 1024 * 1024 * 1024;
831 max_chunk_size = 10 * calc_size;
832 min_stripe_size = 64 * 1024 * 1024;
833 max_stripes = BTRFS_MAX_DEVS(chunk_root);
834 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
835 calc_size = 1024 * 1024 * 1024;
836 max_chunk_size = 4 * calc_size;
837 min_stripe_size = 32 * 1024 * 1024;
838 max_stripes = BTRFS_MAX_DEVS(chunk_root);
839 }
840 }
841 if (type & BTRFS_BLOCK_GROUP_RAID1) {
842 num_stripes = min_t(u64, 2,
843 btrfs_super_num_devices(info->super_copy));
844 if (num_stripes < 2)
845 return -ENOSPC;
846 min_stripes = 2;
847 }
848 if (type & BTRFS_BLOCK_GROUP_DUP) {
849 num_stripes = 2;
850 min_stripes = 2;
851 }
852 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
853 num_stripes = btrfs_super_num_devices(info->super_copy);
854 if (num_stripes > max_stripes)
855 num_stripes = max_stripes;
856 min_stripes = 2;
857 }
858 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
859 num_stripes = btrfs_super_num_devices(info->super_copy);
860 if (num_stripes > max_stripes)
861 num_stripes = max_stripes;
862 if (num_stripes < 4)
863 return -ENOSPC;
864 num_stripes &= ~(u32)1;
865 sub_stripes = 2;
866 min_stripes = 4;
867 }
868 if (type & (BTRFS_BLOCK_GROUP_RAID5)) {
869 num_stripes = btrfs_super_num_devices(info->super_copy);
870 if (num_stripes > max_stripes)
871 num_stripes = max_stripes;
872 if (num_stripes < 2)
873 return -ENOSPC;
874 min_stripes = 2;
875 stripe_len = find_raid56_stripe_len(num_stripes - 1,
876 btrfs_super_stripesize(info->super_copy));
877 }
878 if (type & (BTRFS_BLOCK_GROUP_RAID6)) {
879 num_stripes = btrfs_super_num_devices(info->super_copy);
880 if (num_stripes > max_stripes)
881 num_stripes = max_stripes;
882 if (num_stripes < 3)
883 return -ENOSPC;
884 min_stripes = 3;
885 stripe_len = find_raid56_stripe_len(num_stripes - 2,
886 btrfs_super_stripesize(info->super_copy));
887 }
888
889 /* we don't want a chunk larger than 10% of the FS */
890 percent_max = div_factor(btrfs_super_total_bytes(info->super_copy), 1);
891 max_chunk_size = min(percent_max, max_chunk_size);
892
893 again:
894 if (chunk_bytes_by_type(type, calc_size, num_stripes, sub_stripes) >
895 max_chunk_size) {
896 calc_size = max_chunk_size;
897 calc_size /= num_stripes;
898 calc_size /= stripe_len;
899 calc_size *= stripe_len;
900 }
901 /* we don't want tiny stripes */
902 calc_size = max_t(u64, calc_size, min_stripe_size);
903
904 calc_size /= stripe_len;
905 calc_size *= stripe_len;
906 INIT_LIST_HEAD(&private_devs);
907 cur = dev_list->next;
908 index = 0;
909
910 if (type & BTRFS_BLOCK_GROUP_DUP)
911 min_free = calc_size * 2;
912 else
913 min_free = calc_size;
914
915 /* build a private list of devices we will allocate from */
916 while(index < num_stripes) {
917 device = list_entry(cur, struct btrfs_device, dev_list);
918 ret = btrfs_device_avail_bytes(trans, device, &avail);
919 if (ret)
920 return ret;
921 cur = cur->next;
922 if (avail >= min_free) {
923 list_move_tail(&device->dev_list, &private_devs);
924 index++;
925 if (type & BTRFS_BLOCK_GROUP_DUP)
926 index++;
927 } else if (avail > max_avail)
928 max_avail = avail;
929 if (cur == dev_list)
930 break;
931 }
932 if (index < num_stripes) {
933 list_splice(&private_devs, dev_list);
934 if (index >= min_stripes) {
935 num_stripes = index;
936 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
937 num_stripes /= sub_stripes;
938 num_stripes *= sub_stripes;
939 }
940 looped = 1;
941 goto again;
942 }
943 if (!looped && max_avail > 0) {
944 looped = 1;
945 calc_size = max_avail;
946 goto again;
947 }
948 return -ENOSPC;
949 }
950 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
951 &offset);
952 if (ret)
953 return ret;
954 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
955 key.type = BTRFS_CHUNK_ITEM_KEY;
956 key.offset = offset;
957
958 chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
959 if (!chunk)
960 return -ENOMEM;
961
962 map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
963 if (!map) {
964 kfree(chunk);
965 return -ENOMEM;
966 }
967
968 stripes = &chunk->stripe;
969 *num_bytes = chunk_bytes_by_type(type, calc_size,
970 num_stripes, sub_stripes);
971 index = 0;
972 while(index < num_stripes) {
973 struct btrfs_stripe *stripe;
974 BUG_ON(list_empty(&private_devs));
975 cur = private_devs.next;
976 device = list_entry(cur, struct btrfs_device, dev_list);
977
978 /* loop over this device again if we're doing a dup group */
979 if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
980 (index == num_stripes - 1))
981 list_move_tail(&device->dev_list, dev_list);
982
983 ret = btrfs_alloc_dev_extent(trans, device,
984 info->chunk_root->root_key.objectid,
985 BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
986 calc_size, &dev_offset);
987 BUG_ON(ret);
988
989 device->bytes_used += calc_size;
990 ret = btrfs_update_device(trans, device);
991 BUG_ON(ret);
992
993 map->stripes[index].dev = device;
994 map->stripes[index].physical = dev_offset;
995 stripe = stripes + index;
996 btrfs_set_stack_stripe_devid(stripe, device->devid);
997 btrfs_set_stack_stripe_offset(stripe, dev_offset);
998 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
999 index++;
1000 }
1001 BUG_ON(!list_empty(&private_devs));
1002
1003 /* key was set above */
1004 btrfs_set_stack_chunk_length(chunk, *num_bytes);
1005 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
1006 btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
1007 btrfs_set_stack_chunk_type(chunk, type);
1008 btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
1009 btrfs_set_stack_chunk_io_align(chunk, stripe_len);
1010 btrfs_set_stack_chunk_io_width(chunk, stripe_len);
1011 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
1012 btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
1013 map->sector_size = extent_root->sectorsize;
1014 map->stripe_len = stripe_len;
1015 map->io_align = stripe_len;
1016 map->io_width = stripe_len;
1017 map->type = type;
1018 map->num_stripes = num_stripes;
1019 map->sub_stripes = sub_stripes;
1020
1021 ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
1022 btrfs_chunk_item_size(num_stripes));
1023 BUG_ON(ret);
1024 *start = key.offset;;
1025
1026 map->ce.start = key.offset;
1027 map->ce.size = *num_bytes;
1028
1029 ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
1030 BUG_ON(ret);
1031
1032 if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
1033 ret = btrfs_add_system_chunk(trans, chunk_root, &key,
1034 chunk, btrfs_chunk_item_size(num_stripes));
1035 BUG_ON(ret);
1036 }
1037
1038 kfree(chunk);
1039 return ret;
1040 }
1041
1042 int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
1043 struct btrfs_root *extent_root, u64 *start,
1044 u64 num_bytes, u64 type)
1045 {
1046 u64 dev_offset;
1047 struct btrfs_fs_info *info = extent_root->fs_info;
1048 struct btrfs_root *chunk_root = info->chunk_root;
1049 struct btrfs_stripe *stripes;
1050 struct btrfs_device *device = NULL;
1051 struct btrfs_chunk *chunk;
1052 struct list_head *dev_list = &info->fs_devices->devices;
1053 struct list_head *cur;
1054 struct map_lookup *map;
1055 u64 calc_size = 8 * 1024 * 1024;
1056 int num_stripes = 1;
1057 int sub_stripes = 0;
1058 int ret;
1059 int index;
1060 int stripe_len = BTRFS_STRIPE_LEN;
1061 struct btrfs_key key;
1062
1063 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1064 key.type = BTRFS_CHUNK_ITEM_KEY;
1065 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
1066 &key.offset);
1067 if (ret)
1068 return ret;
1069
1070 chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
1071 if (!chunk)
1072 return -ENOMEM;
1073
1074 map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
1075 if (!map) {
1076 kfree(chunk);
1077 return -ENOMEM;
1078 }
1079
1080 stripes = &chunk->stripe;
1081 calc_size = num_bytes;
1082
1083 index = 0;
1084 cur = dev_list->next;
1085 device = list_entry(cur, struct btrfs_device, dev_list);
1086
1087 while (index < num_stripes) {
1088 struct btrfs_stripe *stripe;
1089
1090 ret = btrfs_alloc_dev_extent(trans, device,
1091 info->chunk_root->root_key.objectid,
1092 BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
1093 calc_size, &dev_offset);
1094 BUG_ON(ret);
1095
1096 device->bytes_used += calc_size;
1097 ret = btrfs_update_device(trans, device);
1098 BUG_ON(ret);
1099
1100 map->stripes[index].dev = device;
1101 map->stripes[index].physical = dev_offset;
1102 stripe = stripes + index;
1103 btrfs_set_stack_stripe_devid(stripe, device->devid);
1104 btrfs_set_stack_stripe_offset(stripe, dev_offset);
1105 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
1106 index++;
1107 }
1108
1109 /* key was set above */
1110 btrfs_set_stack_chunk_length(chunk, num_bytes);
1111 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
1112 btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
1113 btrfs_set_stack_chunk_type(chunk, type);
1114 btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
1115 btrfs_set_stack_chunk_io_align(chunk, stripe_len);
1116 btrfs_set_stack_chunk_io_width(chunk, stripe_len);
1117 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
1118 btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
1119 map->sector_size = extent_root->sectorsize;
1120 map->stripe_len = stripe_len;
1121 map->io_align = stripe_len;
1122 map->io_width = stripe_len;
1123 map->type = type;
1124 map->num_stripes = num_stripes;
1125 map->sub_stripes = sub_stripes;
1126
1127 ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
1128 btrfs_chunk_item_size(num_stripes));
1129 BUG_ON(ret);
1130 *start = key.offset;
1131
1132 map->ce.start = key.offset;
1133 map->ce.size = num_bytes;
1134
1135 ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
1136 BUG_ON(ret);
1137
1138 kfree(chunk);
1139 return ret;
1140 }
1141
1142 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
1143 {
1144 struct cache_extent *ce;
1145 struct map_lookup *map;
1146 int ret;
1147
1148 ce = search_cache_extent(&map_tree->cache_tree, logical);
1149 if (!ce) {
1150 fprintf(stderr, "No mapping for %llu-%llu\n",
1151 (unsigned long long)logical,
1152 (unsigned long long)logical+len);
1153 return 1;
1154 }
1155 if (ce->start > logical || ce->start + ce->size < logical) {
1156 fprintf(stderr, "Invalid mapping for %llu-%llu, got "
1157 "%llu-%llu\n", (unsigned long long)logical,
1158 (unsigned long long)logical+len,
1159 (unsigned long long)ce->start,
1160 (unsigned long long)ce->start + ce->size);
1161 return 1;
1162 }
1163 map = container_of(ce, struct map_lookup, ce);
1164
1165 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
1166 ret = map->num_stripes;
1167 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
1168 ret = map->sub_stripes;
1169 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
1170 ret = 2;
1171 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
1172 ret = 3;
1173 else
1174 ret = 1;
1175 return ret;
1176 }
1177
1178 int btrfs_next_metadata(struct btrfs_mapping_tree *map_tree, u64 *logical,
1179 u64 *size)
1180 {
1181 struct cache_extent *ce;
1182 struct map_lookup *map;
1183
1184 ce = search_cache_extent(&map_tree->cache_tree, *logical);
1185
1186 while (ce) {
1187 ce = next_cache_extent(ce);
1188 if (!ce)
1189 return -ENOENT;
1190
1191 map = container_of(ce, struct map_lookup, ce);
1192 if (map->type & BTRFS_BLOCK_GROUP_METADATA) {
1193 *logical = ce->start;
1194 *size = ce->size;
1195 return 0;
1196 }
1197 }
1198
1199 return -ENOENT;
1200 }
1201
1202 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
1203 u64 chunk_start, u64 physical, u64 devid,
1204 u64 **logical, int *naddrs, int *stripe_len)
1205 {
1206 struct cache_extent *ce;
1207 struct map_lookup *map;
1208 u64 *buf;
1209 u64 bytenr;
1210 u64 length;
1211 u64 stripe_nr;
1212 u64 rmap_len;
1213 int i, j, nr = 0;
1214
1215 ce = search_cache_extent(&map_tree->cache_tree, chunk_start);
1216 BUG_ON(!ce);
1217 map = container_of(ce, struct map_lookup, ce);
1218
1219 length = ce->size;
1220 rmap_len = map->stripe_len;
1221 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
1222 length = ce->size / (map->num_stripes / map->sub_stripes);
1223 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
1224 length = ce->size / map->num_stripes;
1225 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
1226 BTRFS_BLOCK_GROUP_RAID6)) {
1227 length = ce->size / nr_data_stripes(map);
1228 rmap_len = map->stripe_len * nr_data_stripes(map);
1229 }
1230
1231 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
1232
1233 for (i = 0; i < map->num_stripes; i++) {
1234 if (devid && map->stripes[i].dev->devid != devid)
1235 continue;
1236 if (map->stripes[i].physical > physical ||
1237 map->stripes[i].physical + length <= physical)
1238 continue;
1239
1240 stripe_nr = (physical - map->stripes[i].physical) /
1241 map->stripe_len;
1242
1243 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1244 stripe_nr = (stripe_nr * map->num_stripes + i) /
1245 map->sub_stripes;
1246 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
1247 stripe_nr = stripe_nr * map->num_stripes + i;
1248 } /* else if RAID[56], multiply by nr_data_stripes().
1249 * Alternatively, just use rmap_len below instead of
1250 * map->stripe_len */
1251
1252 bytenr = ce->start + stripe_nr * rmap_len;
1253 for (j = 0; j < nr; j++) {
1254 if (buf[j] == bytenr)
1255 break;
1256 }
1257 if (j == nr)
1258 buf[nr++] = bytenr;
1259 }
1260
1261 *logical = buf;
1262 *naddrs = nr;
1263 *stripe_len = rmap_len;
1264
1265 return 0;
1266 }
1267
1268 static inline int parity_smaller(u64 a, u64 b)
1269 {
1270 return a > b;
1271 }
1272
1273 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
1274 static void sort_parity_stripes(struct btrfs_multi_bio *bbio, u64 *raid_map)
1275 {
1276 struct btrfs_bio_stripe s;
1277 int i;
1278 u64 l;
1279 int again = 1;
1280
1281 while (again) {
1282 again = 0;
1283 for (i = 0; i < bbio->num_stripes - 1; i++) {
1284 if (parity_smaller(raid_map[i], raid_map[i+1])) {
1285 s = bbio->stripes[i];
1286 l = raid_map[i];
1287 bbio->stripes[i] = bbio->stripes[i+1];
1288 raid_map[i] = raid_map[i+1];
1289 bbio->stripes[i+1] = s;
1290 raid_map[i+1] = l;
1291 again = 1;
1292 }
1293 }
1294 }
1295 }
1296
1297 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1298 u64 logical, u64 *length,
1299 struct btrfs_multi_bio **multi_ret, int mirror_num,
1300 u64 **raid_map_ret)
1301 {
1302 return __btrfs_map_block(map_tree, rw, logical, length, NULL,
1303 multi_ret, mirror_num, raid_map_ret);
1304 }
1305
1306 int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1307 u64 logical, u64 *length, u64 *type,
1308 struct btrfs_multi_bio **multi_ret, int mirror_num,
1309 u64 **raid_map_ret)
1310 {
1311 struct cache_extent *ce;
1312 struct map_lookup *map;
1313 u64 offset;
1314 u64 stripe_offset;
1315 u64 stripe_nr;
1316 u64 *raid_map = NULL;
1317 int stripes_allocated = 8;
1318 int stripes_required = 1;
1319 int stripe_index;
1320 int i;
1321 struct btrfs_multi_bio *multi = NULL;
1322
1323 if (multi_ret && rw == READ) {
1324 stripes_allocated = 1;
1325 }
1326 again:
1327 ce = search_cache_extent(&map_tree->cache_tree, logical);
1328 if (!ce) {
1329 kfree(multi);
1330 *length = (u64)-1;
1331 return -ENOENT;
1332 }
1333 if (ce->start > logical) {
1334 kfree(multi);
1335 *length = ce->start - logical;
1336 return -ENOENT;
1337 }
1338
1339 if (multi_ret) {
1340 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
1341 GFP_NOFS);
1342 if (!multi)
1343 return -ENOMEM;
1344 }
1345 map = container_of(ce, struct map_lookup, ce);
1346 offset = logical - ce->start;
1347
1348 if (rw == WRITE) {
1349 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
1350 BTRFS_BLOCK_GROUP_DUP)) {
1351 stripes_required = map->num_stripes;
1352 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1353 stripes_required = map->sub_stripes;
1354 }
1355 }
1356 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)
1357 && multi_ret && ((rw & WRITE) || mirror_num > 1) && raid_map_ret) {
1358 /* RAID[56] write or recovery. Return all stripes */
1359 stripes_required = map->num_stripes;
1360
1361 /* Only allocate the map if we've already got a large enough multi_ret */
1362 if (stripes_allocated >= stripes_required) {
1363 raid_map = kmalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
1364 if (!raid_map) {
1365 kfree(multi);
1366 return -ENOMEM;
1367 }
1368 }
1369 }
1370
1371 /* if our multi bio struct is too small, back off and try again */
1372 if (multi_ret && stripes_allocated < stripes_required) {
1373 stripes_allocated = stripes_required;
1374 kfree(multi);
1375 multi = NULL;
1376 goto again;
1377 }
1378 stripe_nr = offset;
1379 /*
1380 * stripe_nr counts the total number of stripes we have to stride
1381 * to get to this block
1382 */
1383 stripe_nr = stripe_nr / map->stripe_len;
1384
1385 stripe_offset = stripe_nr * map->stripe_len;
1386 BUG_ON(offset < stripe_offset);
1387
1388 /* stripe_offset is the offset of this block in its stripe*/
1389 stripe_offset = offset - stripe_offset;
1390
1391 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
1392 BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
1393 BTRFS_BLOCK_GROUP_RAID10 |
1394 BTRFS_BLOCK_GROUP_DUP)) {
1395 /* we limit the length of each bio to what fits in a stripe */
1396 *length = min_t(u64, ce->size - offset,
1397 map->stripe_len - stripe_offset);
1398 } else {
1399 *length = ce->size - offset;
1400 }
1401
1402 if (!multi_ret)
1403 goto out;
1404
1405 multi->num_stripes = 1;
1406 stripe_index = 0;
1407 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1408 if (rw == WRITE)
1409 multi->num_stripes = map->num_stripes;
1410 else if (mirror_num)
1411 stripe_index = mirror_num - 1;
1412 else
1413 stripe_index = stripe_nr % map->num_stripes;
1414 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1415 int factor = map->num_stripes / map->sub_stripes;
1416
1417 stripe_index = stripe_nr % factor;
1418 stripe_index *= map->sub_stripes;
1419
1420 if (rw == WRITE)
1421 multi->num_stripes = map->sub_stripes;
1422 else if (mirror_num)
1423 stripe_index += mirror_num - 1;
1424
1425 stripe_nr = stripe_nr / factor;
1426 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1427 if (rw == WRITE)
1428 multi->num_stripes = map->num_stripes;
1429 else if (mirror_num)
1430 stripe_index = mirror_num - 1;
1431 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
1432 BTRFS_BLOCK_GROUP_RAID6)) {
1433
1434 if (raid_map) {
1435 int rot;
1436 u64 tmp;
1437 u64 raid56_full_stripe_start;
1438 u64 full_stripe_len = nr_data_stripes(map) * map->stripe_len;
1439
1440 /*
1441 * align the start of our data stripe in the logical
1442 * address space
1443 */
1444 raid56_full_stripe_start = offset / full_stripe_len;
1445 raid56_full_stripe_start *= full_stripe_len;
1446
1447 /* get the data stripe number */
1448 stripe_nr = raid56_full_stripe_start / map->stripe_len;
1449 stripe_nr = stripe_nr / nr_data_stripes(map);
1450
1451 /* Work out the disk rotation on this stripe-set */
1452 rot = stripe_nr % map->num_stripes;
1453
1454 /* Fill in the logical address of each stripe */
1455 tmp = stripe_nr * nr_data_stripes(map);
1456
1457 for (i = 0; i < nr_data_stripes(map); i++)
1458 raid_map[(i+rot) % map->num_stripes] =
1459 ce->start + (tmp + i) * map->stripe_len;
1460
1461 raid_map[(i+rot) % map->num_stripes] = BTRFS_RAID5_P_STRIPE;
1462 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
1463 raid_map[(i+rot+1) % map->num_stripes] = BTRFS_RAID6_Q_STRIPE;
1464
1465 *length = map->stripe_len;
1466 stripe_index = 0;
1467 stripe_offset = 0;
1468 multi->num_stripes = map->num_stripes;
1469 } else {
1470 stripe_index = stripe_nr % nr_data_stripes(map);
1471 stripe_nr = stripe_nr / nr_data_stripes(map);
1472
1473 /*
1474 * Mirror #0 or #1 means the original data block.
1475 * Mirror #2 is RAID5 parity block.
1476 * Mirror #3 is RAID6 Q block.
1477 */
1478 if (mirror_num > 1)
1479 stripe_index = nr_data_stripes(map) + mirror_num - 2;
1480
1481 /* We distribute the parity blocks across stripes */
1482 stripe_index = (stripe_nr + stripe_index) % map->num_stripes;
1483 }
1484 } else {
1485 /*
1486 * after this do_div call, stripe_nr is the number of stripes
1487 * on this device we have to walk to find the data, and
1488 * stripe_index is the number of our device in the stripe array
1489 */
1490 stripe_index = stripe_nr % map->num_stripes;
1491 stripe_nr = stripe_nr / map->num_stripes;
1492 }
1493 BUG_ON(stripe_index >= map->num_stripes);
1494
1495 for (i = 0; i < multi->num_stripes; i++) {
1496 multi->stripes[i].physical =
1497 map->stripes[stripe_index].physical + stripe_offset +
1498 stripe_nr * map->stripe_len;
1499 multi->stripes[i].dev = map->stripes[stripe_index].dev;
1500 stripe_index++;
1501 }
1502 *multi_ret = multi;
1503
1504 if (type)
1505 *type = map->type;
1506
1507 if (raid_map) {
1508 sort_parity_stripes(multi, raid_map);
1509 *raid_map_ret = raid_map;
1510 }
1511 out:
1512 return 0;
1513 }
1514
1515 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
1516 u8 *uuid, u8 *fsid)
1517 {
1518 struct btrfs_device *device;
1519 struct btrfs_fs_devices *cur_devices;
1520
1521 cur_devices = root->fs_info->fs_devices;
1522 while (cur_devices) {
1523 if (!fsid ||
1524 (!memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE) ||
1525 root->fs_info->ignore_fsid_mismatch)) {
1526 device = __find_device(&cur_devices->devices,
1527 devid, uuid);
1528 if (device)
1529 return device;
1530 }
1531 cur_devices = cur_devices->seed;
1532 }
1533 return NULL;
1534 }
1535
1536 struct btrfs_device *
1537 btrfs_find_device_by_devid(struct btrfs_fs_devices *fs_devices,
1538 u64 devid, int instance)
1539 {
1540 struct list_head *head = &fs_devices->devices;
1541 struct btrfs_device *dev;
1542 int num_found = 0;
1543
1544 list_for_each_entry(dev, head, dev_list) {
1545 if (dev->devid == devid && num_found++ == instance)
1546 return dev;
1547 }
1548 return NULL;
1549 }
1550
1551 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
1552 {
1553 struct cache_extent *ce;
1554 struct map_lookup *map;
1555 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1556 int readonly = 0;
1557 int i;
1558
1559 /*
1560 * During chunk recovering, we may fail to find block group's
1561 * corresponding chunk, we will rebuild it later
1562 */
1563 ce = search_cache_extent(&map_tree->cache_tree, chunk_offset);
1564 if (!root->fs_info->is_chunk_recover)
1565 BUG_ON(!ce);
1566 else
1567 return 0;
1568
1569 map = container_of(ce, struct map_lookup, ce);
1570 for (i = 0; i < map->num_stripes; i++) {
1571 if (!map->stripes[i].dev->writeable) {
1572 readonly = 1;
1573 break;
1574 }
1575 }
1576
1577 return readonly;
1578 }
1579
1580 static struct btrfs_device *fill_missing_device(u64 devid)
1581 {
1582 struct btrfs_device *device;
1583
1584 device = kzalloc(sizeof(*device), GFP_NOFS);
1585 device->devid = devid;
1586 device->fd = -1;
1587 return device;
1588 }
1589
1590 /*
1591 * Slot is used to verfy the chunk item is valid
1592 *
1593 * For sys chunk in superblock, pass -1 to indicate sys chunk.
1594 */
1595 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
1596 struct extent_buffer *leaf,
1597 struct btrfs_chunk *chunk, int slot)
1598 {
1599 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1600 struct map_lookup *map;
1601 struct cache_extent *ce;
1602 u64 logical;
1603 u64 length;
1604 u64 devid;
1605 u8 uuid[BTRFS_UUID_SIZE];
1606 int num_stripes;
1607 int ret;
1608 int i;
1609
1610 logical = key->offset;
1611 length = btrfs_chunk_length(leaf, chunk);
1612
1613 ce = search_cache_extent(&map_tree->cache_tree, logical);
1614
1615 /* already mapped? */
1616 if (ce && ce->start <= logical && ce->start + ce->size > logical) {
1617 return 0;
1618 }
1619
1620 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
1621 map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
1622 if (!map)
1623 return -ENOMEM;
1624
1625 map->ce.start = logical;
1626 map->ce.size = length;
1627 map->num_stripes = num_stripes;
1628 map->io_width = btrfs_chunk_io_width(leaf, chunk);
1629 map->io_align = btrfs_chunk_io_align(leaf, chunk);
1630 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
1631 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
1632 map->type = btrfs_chunk_type(leaf, chunk);
1633 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
1634
1635 /* Check on chunk item type */
1636 if (map->type & ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
1637 BTRFS_BLOCK_GROUP_PROFILE_MASK)) {
1638 fprintf(stderr, "Unknown chunk type bits: %llu\n",
1639 map->type & ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
1640 BTRFS_BLOCK_GROUP_PROFILE_MASK));
1641 ret = -EIO;
1642 goto out;
1643 }
1644
1645 /*
1646 * Btrfs_chunk contains at least one stripe, and for sys_chunk
1647 * it can't exceed the system chunk array size
1648 * For normal chunk, it should match its chunk item size.
1649 */
1650 if (num_stripes < 1 ||
1651 (slot == -1 && sizeof(struct btrfs_stripe) * num_stripes >
1652 BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) ||
1653 (slot >= 0 && sizeof(struct btrfs_stripe) * (num_stripes - 1) >
1654 btrfs_item_size_nr(leaf, slot))) {
1655 fprintf(stderr, "Invalid num_stripes: %u\n",
1656 num_stripes);
1657 ret = -EIO;
1658 goto out;
1659 }
1660
1661 /*
1662 * Device number check against profile
1663 */
1664 if ((map->type & BTRFS_BLOCK_GROUP_RAID10 && map->sub_stripes == 0) ||
1665 (map->type & BTRFS_BLOCK_GROUP_RAID1 && num_stripes < 1) ||
1666 (map->type & BTRFS_BLOCK_GROUP_RAID5 && num_stripes < 2) ||
1667 (map->type & BTRFS_BLOCK_GROUP_RAID6 && num_stripes < 3) ||
1668 (map->type & BTRFS_BLOCK_GROUP_DUP && num_stripes > 2) ||
1669 ((map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 &&
1670 num_stripes != 1)) {
1671 fprintf(stderr,
1672 "Invalid num_stripes:sub_stripes %u:%u for profile %llu\n",
1673 num_stripes, map->sub_stripes,
1674 map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK);
1675 ret = -EIO;
1676 goto out;
1677 }
1678
1679 for (i = 0; i < num_stripes; i++) {
1680 map->stripes[i].physical =
1681 btrfs_stripe_offset_nr(leaf, chunk, i);
1682 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
1683 read_extent_buffer(leaf, uuid, (unsigned long)
1684 btrfs_stripe_dev_uuid_nr(chunk, i),
1685 BTRFS_UUID_SIZE);
1686 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
1687 NULL);
1688 if (!map->stripes[i].dev) {
1689 map->stripes[i].dev = fill_missing_device(devid);
1690 printf("warning, device %llu is missing\n",
1691 (unsigned long long)devid);
1692 }
1693
1694 }
1695 ret = insert_cache_extent(&map_tree->cache_tree, &map->ce);
1696 BUG_ON(ret);
1697
1698 return 0;
1699 out:
1700 free(map);
1701 return ret;
1702 }
1703
1704 static int fill_device_from_item(struct extent_buffer *leaf,
1705 struct btrfs_dev_item *dev_item,
1706 struct btrfs_device *device)
1707 {
1708 unsigned long ptr;
1709
1710 device->devid = btrfs_device_id(leaf, dev_item);
1711 device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
1712 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
1713 device->type = btrfs_device_type(leaf, dev_item);
1714 device->io_align = btrfs_device_io_align(leaf, dev_item);
1715 device->io_width = btrfs_device_io_width(leaf, dev_item);
1716 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
1717
1718 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1719 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1720
1721 return 0;
1722 }
1723
1724 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
1725 {
1726 struct btrfs_fs_devices *fs_devices;
1727 int ret;
1728
1729 fs_devices = root->fs_info->fs_devices->seed;
1730 while (fs_devices) {
1731 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
1732 ret = 0;
1733 goto out;
1734 }
1735 fs_devices = fs_devices->seed;
1736 }
1737
1738 fs_devices = find_fsid(fsid);
1739 if (!fs_devices) {
1740 /* missing all seed devices */
1741 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1742 if (!fs_devices) {
1743 ret = -ENOMEM;
1744 goto out;
1745 }
1746 INIT_LIST_HEAD(&fs_devices->devices);
1747 list_add(&fs_devices->list, &fs_uuids);
1748 memcpy(fs_devices->fsid, fsid, BTRFS_FSID_SIZE);
1749 }
1750
1751 ret = btrfs_open_devices(fs_devices, O_RDONLY);
1752 if (ret)
1753 goto out;
1754
1755 fs_devices->seed = root->fs_info->fs_devices->seed;
1756 root->fs_info->fs_devices->seed = fs_devices;
1757 out:
1758 return ret;
1759 }
1760
1761 static int read_one_dev(struct btrfs_root *root,
1762 struct extent_buffer *leaf,
1763 struct btrfs_dev_item *dev_item)
1764 {
1765 struct btrfs_device *device;
1766 u64 devid;
1767 int ret = 0;
1768 u8 fs_uuid[BTRFS_UUID_SIZE];
1769 u8 dev_uuid[BTRFS_UUID_SIZE];
1770
1771 devid = btrfs_device_id(leaf, dev_item);
1772 read_extent_buffer(leaf, dev_uuid,
1773 (unsigned long)btrfs_device_uuid(dev_item),
1774 BTRFS_UUID_SIZE);
1775 read_extent_buffer(leaf, fs_uuid,
1776 (unsigned long)btrfs_device_fsid(dev_item),
1777 BTRFS_UUID_SIZE);
1778
1779 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
1780 ret = open_seed_devices(root, fs_uuid);
1781 if (ret)
1782 return ret;
1783 }
1784
1785 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1786 if (!device) {
1787 printk("warning devid %llu not found already\n",
1788 (unsigned long long)devid);
1789 device = kzalloc(sizeof(*device), GFP_NOFS);
1790 if (!device)
1791 return -ENOMEM;
1792 device->fd = -1;
1793 list_add(&device->dev_list,
1794 &root->fs_info->fs_devices->devices);
1795 }
1796
1797 fill_device_from_item(leaf, dev_item, device);
1798 device->dev_root = root->fs_info->dev_root;
1799 return ret;
1800 }
1801
1802 int btrfs_read_sys_array(struct btrfs_root *root)
1803 {
1804 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1805 struct extent_buffer *sb;
1806 struct btrfs_disk_key *disk_key;
1807 struct btrfs_chunk *chunk;
1808 struct btrfs_key key;
1809 u32 num_stripes;
1810 u32 len = 0;
1811 u8 *ptr;
1812 u8 *array_end;
1813 int ret = 0;
1814
1815 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
1816 BTRFS_SUPER_INFO_SIZE);
1817 if (!sb)
1818 return -ENOMEM;
1819 btrfs_set_buffer_uptodate(sb);
1820 write_extent_buffer(sb, super_copy, 0, sizeof(*super_copy));
1821 array_end = ((u8 *)super_copy->sys_chunk_array) +
1822 btrfs_super_sys_array_size(super_copy);
1823
1824 /*
1825 * we do this loop twice, once for the device items and
1826 * once for all of the chunks. This way there are device
1827 * structs filled in for every chunk
1828 */
1829 ptr = super_copy->sys_chunk_array;
1830
1831 while (ptr < array_end) {
1832 disk_key = (struct btrfs_disk_key *)ptr;
1833 btrfs_disk_key_to_cpu(&key, disk_key);
1834
1835 len = sizeof(*disk_key);
1836 ptr += len;
1837
1838 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1839 chunk = (struct btrfs_chunk *)(ptr - (u8 *)super_copy);
1840 ret = read_one_chunk(root, &key, sb, chunk, -1);
1841 if (ret)
1842 break;
1843 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
1844 len = btrfs_chunk_item_size(num_stripes);
1845 } else {
1846 BUG();
1847 }
1848 ptr += len;
1849 }
1850 free_extent_buffer(sb);
1851 return ret;
1852 }
1853
1854 int btrfs_read_chunk_tree(struct btrfs_root *root)
1855 {
1856 struct btrfs_path *path;
1857 struct extent_buffer *leaf;
1858 struct btrfs_key key;
1859 struct btrfs_key found_key;
1860 int ret;
1861 int slot;
1862
1863 root = root->fs_info->chunk_root;
1864
1865 path = btrfs_alloc_path();
1866 if (!path)
1867 return -ENOMEM;
1868
1869 /*
1870 * Read all device items, and then all the chunk items. All
1871 * device items are found before any chunk item (their object id
1872 * is smaller than the lowest possible object id for a chunk
1873 * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
1874 */
1875 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1876 key.offset = 0;
1877 key.type = 0;
1878 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1879 if (ret < 0)
1880 goto error;
1881 while(1) {
1882 leaf = path->nodes[0];
1883 slot = path->slots[0];
1884 if (slot >= btrfs_header_nritems(leaf)) {
1885 ret = btrfs_next_leaf(root, path);
1886 if (ret == 0)
1887 continue;
1888 if (ret < 0)
1889 goto error;
1890 break;
1891 }
1892 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1893 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
1894 struct btrfs_dev_item *dev_item;
1895 dev_item = btrfs_item_ptr(leaf, slot,
1896 struct btrfs_dev_item);
1897 ret = read_one_dev(root, leaf, dev_item);
1898 BUG_ON(ret);
1899 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
1900 struct btrfs_chunk *chunk;
1901 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
1902 ret = read_one_chunk(root, &found_key, leaf, chunk,
1903 slot);
1904 BUG_ON(ret);
1905 }
1906 path->slots[0]++;
1907 }
1908
1909 ret = 0;
1910 error:
1911 btrfs_free_path(path);
1912 return ret;
1913 }
1914
1915 struct list_head *btrfs_scanned_uuids(void)
1916 {
1917 return &fs_uuids;
1918 }
1919
1920 static int rmw_eb(struct btrfs_fs_info *info,
1921 struct extent_buffer *eb, struct extent_buffer *orig_eb)
1922 {
1923 int ret;
1924 unsigned long orig_off = 0;
1925 unsigned long dest_off = 0;
1926 unsigned long copy_len = eb->len;
1927
1928 ret = read_whole_eb(info, eb, 0);
1929 if (ret)
1930 return ret;
1931
1932 if (eb->start + eb->len <= orig_eb->start ||
1933 eb->start >= orig_eb->start + orig_eb->len)
1934 return 0;
1935 /*
1936 * | ----- orig_eb ------- |
1937 * | ----- stripe ------- |
1938 * | ----- orig_eb ------- |
1939 * | ----- orig_eb ------- |
1940 */
1941 if (eb->start > orig_eb->start)
1942 orig_off = eb->start - orig_eb->start;
1943 if (orig_eb->start > eb->start)
1944 dest_off = orig_eb->start - eb->start;
1945
1946 if (copy_len > orig_eb->len - orig_off)
1947 copy_len = orig_eb->len - orig_off;
1948 if (copy_len > eb->len - dest_off)
1949 copy_len = eb->len - dest_off;
1950
1951 memcpy(eb->data + dest_off, orig_eb->data + orig_off, copy_len);
1952 return 0;
1953 }
1954
1955 static void split_eb_for_raid56(struct btrfs_fs_info *info,
1956 struct extent_buffer *orig_eb,
1957 struct extent_buffer **ebs,
1958 u64 stripe_len, u64 *raid_map,
1959 int num_stripes)
1960 {
1961 struct extent_buffer *eb;
1962 u64 start = orig_eb->start;
1963 u64 this_eb_start;
1964 int i;
1965 int ret;
1966
1967 for (i = 0; i < num_stripes; i++) {
1968 if (raid_map[i] >= BTRFS_RAID5_P_STRIPE)
1969 break;
1970
1971 eb = malloc(sizeof(struct extent_buffer) + stripe_len);
1972 if (!eb)
1973 BUG();
1974 memset(eb, 0, sizeof(struct extent_buffer) + stripe_len);
1975
1976 eb->start = raid_map[i];
1977 eb->len = stripe_len;
1978 eb->refs = 1;
1979 eb->flags = 0;
1980 eb->fd = -1;
1981 eb->dev_bytenr = (u64)-1;
1982
1983 this_eb_start = raid_map[i];
1984
1985 if (start > this_eb_start ||
1986 start + orig_eb->len < this_eb_start + stripe_len) {
1987 ret = rmw_eb(info, eb, orig_eb);
1988 BUG_ON(ret);
1989 } else {
1990 memcpy(eb->data, orig_eb->data + eb->start - start, stripe_len);
1991 }
1992 ebs[i] = eb;
1993 }
1994 }
1995
1996 int write_raid56_with_parity(struct btrfs_fs_info *info,
1997 struct extent_buffer *eb,
1998 struct btrfs_multi_bio *multi,
1999 u64 stripe_len, u64 *raid_map)
2000 {
2001 struct extent_buffer **ebs, *p_eb = NULL, *q_eb = NULL;
2002 int i;
2003 int j;
2004 int ret;
2005 int alloc_size = eb->len;
2006
2007 ebs = kmalloc(sizeof(*ebs) * multi->num_stripes, GFP_NOFS);
2008 BUG_ON(!ebs);
2009
2010 if (stripe_len > alloc_size)
2011 alloc_size = stripe_len;
2012
2013 split_eb_for_raid56(info, eb, ebs, stripe_len, raid_map,
2014 multi->num_stripes);
2015
2016 for (i = 0; i < multi->num_stripes; i++) {
2017 struct extent_buffer *new_eb;
2018 if (raid_map[i] < BTRFS_RAID5_P_STRIPE) {
2019 ebs[i]->dev_bytenr = multi->stripes[i].physical;
2020 ebs[i]->fd = multi->stripes[i].dev->fd;
2021 multi->stripes[i].dev->total_ios++;
2022 BUG_ON(ebs[i]->start != raid_map[i]);
2023 continue;
2024 }
2025 new_eb = kmalloc(sizeof(*eb) + alloc_size, GFP_NOFS);
2026 BUG_ON(!new_eb);
2027 new_eb->dev_bytenr = multi->stripes[i].physical;
2028 new_eb->fd = multi->stripes[i].dev->fd;
2029 multi->stripes[i].dev->total_ios++;
2030 new_eb->len = stripe_len;
2031
2032 if (raid_map[i] == BTRFS_RAID5_P_STRIPE)
2033 p_eb = new_eb;
2034 else if (raid_map[i] == BTRFS_RAID6_Q_STRIPE)
2035 q_eb = new_eb;
2036 }
2037 if (q_eb) {
2038 void **pointers;
2039
2040 pointers = kmalloc(sizeof(*pointers) * multi->num_stripes,
2041 GFP_NOFS);
2042 BUG_ON(!pointers);
2043
2044 ebs[multi->num_stripes - 2] = p_eb;
2045 ebs[multi->num_stripes - 1] = q_eb;
2046
2047 for (i = 0; i < multi->num_stripes; i++)
2048 pointers[i] = ebs[i]->data;
2049
2050 raid6_gen_syndrome(multi->num_stripes, stripe_len, pointers);
2051 kfree(pointers);
2052 } else {
2053 ebs[multi->num_stripes - 1] = p_eb;
2054 memcpy(p_eb->data, ebs[0]->data, stripe_len);
2055 for (j = 1; j < multi->num_stripes - 1; j++) {
2056 for (i = 0; i < stripe_len; i += sizeof(unsigned long)) {
2057 *(unsigned long *)(p_eb->data + i) ^=
2058 *(unsigned long *)(ebs[j]->data + i);
2059 }
2060 }
2061 }
2062
2063 for (i = 0; i < multi->num_stripes; i++) {
2064 ret = write_extent_to_disk(ebs[i]);
2065 BUG_ON(ret);
2066 if (ebs[i] != eb)
2067 kfree(ebs[i]);
2068 }
2069
2070 kfree(ebs);
2071
2072 return 0;
2073 }
(deprecated) Btrfs progs developments and patch integration