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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs...
[net-next-2.6.git] / fs / btrfs / volumes.c
CommitLineData
0b86a832
CM		 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 <linux/sched.h>
19#include <linux/bio.h>
5a0e3ad6 20#include <linux/slab.h>
8a4b83cc 21#include <linux/buffer_head.h>
f2d8d74d 22#include <linux/blkdev.h>
788f20eb 23#include <linux/random.h>
b765ead5 24#include <linux/iocontext.h>
593060d7 25#include <asm/div64.h>
4b4e25f2 26#include "compat.h"
0b86a832
CM		 27#include "ctree.h"
28#include "extent_map.h"
29#include "disk-io.h"
30#include "transaction.h"
31#include "print-tree.h"
32#include "volumes.h"
8b712842 33#include "async-thread.h"
0b86a832 34
593060d7
CM		 35struct map_lookup {
36 u64 type;
37 int io_align;
38 int io_width;
39 int stripe_len;
40 int sector_size;
41 int num_stripes;
321aecc6 42 int sub_stripes;
cea9e445 43 struct btrfs_bio_stripe stripes[];
593060d7
CM		 44};
45
2b82032c
YZ		 46static int init_first_rw_device(struct btrfs_trans_handle *trans,
47 struct btrfs_root *root,
48 struct btrfs_device *device);
49static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
50
593060d7 51#define map_lookup_size(n) (sizeof(struct map_lookup) + \
cea9e445 52 (sizeof(struct btrfs_bio_stripe) * (n)))
593060d7 53
8a4b83cc
CM		 54static DEFINE_MUTEX(uuid_mutex);
55static LIST_HEAD(fs_uuids);
56
a061fc8d
CM		 57void btrfs_lock_volumes(void)
58{
59 mutex_lock(&uuid_mutex);
60}
61
62void btrfs_unlock_volumes(void)
63{
64 mutex_unlock(&uuid_mutex);
65}
66
7d9eb12c
CM		 67static void lock_chunks(struct btrfs_root *root)
68{
7d9eb12c
CM		 69 mutex_lock(&root->fs_info->chunk_mutex);
70}
71
72static void unlock_chunks(struct btrfs_root *root)
73{
7d9eb12c
CM		 74 mutex_unlock(&root->fs_info->chunk_mutex);
75}
76
e4404d6e
YZ		 77static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
78{
79 struct btrfs_device *device;
80 WARN_ON(fs_devices->opened);
81 while (!list_empty(&fs_devices->devices)) {
82 device = list_entry(fs_devices->devices.next,
83 struct btrfs_device, dev_list);
84 list_del(&device->dev_list);
85 kfree(device->name);
86 kfree(device);
87 }
88 kfree(fs_devices);
89}
90
8a4b83cc
CM		 91int btrfs_cleanup_fs_uuids(void)
92{
93 struct btrfs_fs_devices *fs_devices;
8a4b83cc 94
2b82032c
YZ		 95 while (!list_empty(&fs_uuids)) {
96 fs_devices = list_entry(fs_uuids.next,
97 struct btrfs_fs_devices, list);
98 list_del(&fs_devices->list);
e4404d6e 99 free_fs_devices(fs_devices);
8a4b83cc
CM		 100 }
101 return 0;
102}
103
a1b32a59
CM		 104static noinline struct btrfs_device *__find_device(struct list_head *head,
105 u64 devid, u8 *uuid)
8a4b83cc
CM		 106{
107 struct btrfs_device *dev;
8a4b83cc 108
c6e30871 109 list_for_each_entry(dev, head, dev_list) {
a443755f 110 if (dev->devid == devid &&
8f18cf13 111 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
8a4b83cc 112 return dev;
a443755f 113 }
8a4b83cc
CM		 114 }
115 return NULL;
116}
117
a1b32a59 118static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
8a4b83cc 119{
8a4b83cc
CM		 120 struct btrfs_fs_devices *fs_devices;
121
c6e30871 122 list_for_each_entry(fs_devices, &fs_uuids, list) {
8a4b83cc
CM		 123 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
124 return fs_devices;
125 }
126 return NULL;
127}
128
ffbd517d
CM		 129static void requeue_list(struct btrfs_pending_bios *pending_bios,
130 struct bio *head, struct bio *tail)
131{
132
133 struct bio *old_head;
134
135 old_head = pending_bios->head;
136 pending_bios->head = head;
137 if (pending_bios->tail)
138 tail->bi_next = old_head;
139 else
140 pending_bios->tail = tail;
141}
142
8b712842
CM		 143/*
144 * we try to collect pending bios for a device so we don't get a large
145 * number of procs sending bios down to the same device. This greatly
146 * improves the schedulers ability to collect and merge the bios.
147 *
148 * But, it also turns into a long list of bios to process and that is sure
149 * to eventually make the worker thread block. The solution here is to
150 * make some progress and then put this work struct back at the end of
151 * the list if the block device is congested. This way, multiple devices
152 * can make progress from a single worker thread.
153 */
d397712b 154static noinline int run_scheduled_bios(struct btrfs_device *device)
8b712842
CM		 155{
156 struct bio *pending;
157 struct backing_dev_info *bdi;
b64a2851 158 struct btrfs_fs_info *fs_info;
ffbd517d 159 struct btrfs_pending_bios *pending_bios;
8b712842
CM		 160 struct bio *tail;
161 struct bio *cur;
162 int again = 0;
ffbd517d
CM		 163 unsigned long num_run;
164 unsigned long num_sync_run;
d644d8a1 165 unsigned long batch_run = 0;
b64a2851 166 unsigned long limit;
b765ead5 167 unsigned long last_waited = 0;
d84275c9 168 int force_reg = 0;
8b712842 169
bedf762b 170 bdi = blk_get_backing_dev_info(device->bdev);
b64a2851
CM		 171 fs_info = device->dev_root->fs_info;
172 limit = btrfs_async_submit_limit(fs_info);
173 limit = limit * 2 / 3;
174
ffbd517d
CM		 175 /* we want to make sure that every time we switch from the sync
176 * list to the normal list, we unplug
177 */
178 num_sync_run = 0;
179
8b712842
CM		 180loop:
181 spin_lock(&device->io_lock);
182
a6837051 183loop_lock:
d84275c9 184 num_run = 0;
ffbd517d 185
8b712842
CM		 186 /* take all the bios off the list at once and process them
187 * later on (without the lock held). But, remember the
188 * tail and other pointers so the bios can be properly reinserted
189 * into the list if we hit congestion
190 */
d84275c9 191 if (!force_reg && device->pending_sync_bios.head) {
ffbd517d 192 pending_bios = &device->pending_sync_bios;
d84275c9
CM		 193 force_reg = 1;
194 } else {
ffbd517d 195 pending_bios = &device->pending_bios;
d84275c9
CM		 196 force_reg = 0;
197 }
ffbd517d
CM		 198
199 pending = pending_bios->head;
200 tail = pending_bios->tail;
8b712842 201 WARN_ON(pending && !tail);
8b712842
CM		 202
203 /*
204 * if pending was null this time around, no bios need processing
205 * at all and we can stop. Otherwise it'll loop back up again
206 * and do an additional check so no bios are missed.
207 *
208 * device->running_pending is used to synchronize with the
209 * schedule_bio code.
210 */
ffbd517d
CM		 211 if (device->pending_sync_bios.head == NULL &&
212 device->pending_bios.head == NULL) {
8b712842
CM		 213 again = 0;
214 device->running_pending = 0;
ffbd517d
CM		 215 } else {
216 again = 1;
217 device->running_pending = 1;
8b712842 218 }
ffbd517d
CM		 219
220 pending_bios->head = NULL;
221 pending_bios->tail = NULL;
222
8b712842
CM		 223 spin_unlock(&device->io_lock);
224
ffbd517d
CM		 225 /*
226 * if we're doing the regular priority list, make sure we unplug
227 * for any high prio bios we've sent down
228 */
229 if (pending_bios == &device->pending_bios && num_sync_run > 0) {
230 num_sync_run = 0;
231 blk_run_backing_dev(bdi, NULL);
232 }
233
d397712b 234 while (pending) {
ffbd517d
CM		 235
236 rmb();
d84275c9
CM		 237 /* we want to work on both lists, but do more bios on the
238 * sync list than the regular list
239 */
240 if ((num_run > 32 &&
241 pending_bios != &device->pending_sync_bios &&
242 device->pending_sync_bios.head) ||
243 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
244 device->pending_bios.head)) {
ffbd517d
CM		 245 spin_lock(&device->io_lock);
246 requeue_list(pending_bios, pending, tail);
247 goto loop_lock;
248 }
249
8b712842
CM		 250 cur = pending;
251 pending = pending->bi_next;
252 cur->bi_next = NULL;
b64a2851
CM		 253 atomic_dec(&fs_info->nr_async_bios);
254
255 if (atomic_read(&fs_info->nr_async_bios) < limit &&
256 waitqueue_active(&fs_info->async_submit_wait))
257 wake_up(&fs_info->async_submit_wait);
492bb6de
CM		 258
259 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
d644d8a1 260
7b6d91da 261 if (cur->bi_rw & REQ_SYNC)
ffbd517d
CM		 262 num_sync_run++;
263
5ff7ba3a
CM		 264 submit_bio(cur->bi_rw, cur);
265 num_run++;
266 batch_run++;
ffbd517d
CM		 267 if (need_resched()) {
268 if (num_sync_run) {
269 blk_run_backing_dev(bdi, NULL);
270 num_sync_run = 0;
271 }
272 cond_resched();
273 }
8b712842
CM		 274
275 /*
276 * we made progress, there is more work to do and the bdi
277 * is now congested. Back off and let other work structs
278 * run instead
279 */
57fd5a5f 280 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
5f2cc086 281 fs_info->fs_devices->open_devices > 1) {
b765ead5 282 struct io_context *ioc;
8b712842 283
b765ead5
CM		 284 ioc = current->io_context;
285
286 /*
287 * the main goal here is that we don't want to
288 * block if we're going to be able to submit
289 * more requests without blocking.
290 *
291 * This code does two great things, it pokes into
292 * the elevator code from a filesystem _and_
293 * it makes assumptions about how batching works.
294 */
295 if (ioc && ioc->nr_batch_requests > 0 &&
296 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
297 (last_waited == 0 ||
298 ioc->last_waited == last_waited)) {
299 /*
300 * we want to go through our batch of
301 * requests and stop. So, we copy out
302 * the ioc->last_waited time and test
303 * against it before looping
304 */
305 last_waited = ioc->last_waited;
ffbd517d
CM		 306 if (need_resched()) {
307 if (num_sync_run) {
308 blk_run_backing_dev(bdi, NULL);
309 num_sync_run = 0;
310 }
311 cond_resched();
312 }
b765ead5
CM		 313 continue;
314 }
8b712842 315 spin_lock(&device->io_lock);
ffbd517d 316 requeue_list(pending_bios, pending, tail);
a6837051 317 device->running_pending = 1;
8b712842
CM		 318
319 spin_unlock(&device->io_lock);
320 btrfs_requeue_work(&device->work);
321 goto done;
322 }
323 }
ffbd517d
CM		 324
325 if (num_sync_run) {
326 num_sync_run = 0;
327 blk_run_backing_dev(bdi, NULL);
328 }
bedf762b
CM		 329 /*
330 * IO has already been through a long path to get here. Checksumming,
331 * async helper threads, perhaps compression. We've done a pretty
332 * good job of collecting a batch of IO and should just unplug
333 * the device right away.
334 *
335 * This will help anyone who is waiting on the IO, they might have
336 * already unplugged, but managed to do so before the bio they
337 * cared about found its way down here.
338 */
339 blk_run_backing_dev(bdi, NULL);
51684082
CM		 340
341 cond_resched();
342 if (again)
343 goto loop;
344
345 spin_lock(&device->io_lock);
346 if (device->pending_bios.head || device->pending_sync_bios.head)
347 goto loop_lock;
348 spin_unlock(&device->io_lock);
349
8b712842
CM		 350done:
351 return 0;
352}
353
b2950863 354static void pending_bios_fn(struct btrfs_work *work)
8b712842
CM		 355{
356 struct btrfs_device *device;
357
358 device = container_of(work, struct btrfs_device, work);
359 run_scheduled_bios(device);
360}
361
a1b32a59 362static noinline int device_list_add(const char *path,
8a4b83cc
CM		 363 struct btrfs_super_block *disk_super,
364 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
365{
366 struct btrfs_device *device;
367 struct btrfs_fs_devices *fs_devices;
368 u64 found_transid = btrfs_super_generation(disk_super);
3a0524dc 369 char *name;
8a4b83cc
CM		 370
371 fs_devices = find_fsid(disk_super->fsid);
372 if (!fs_devices) {
515dc322 373 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
8a4b83cc
CM		 374 if (!fs_devices)
375 return -ENOMEM;
376 INIT_LIST_HEAD(&fs_devices->devices);
b3075717 377 INIT_LIST_HEAD(&fs_devices->alloc_list);
8a4b83cc
CM		 378 list_add(&fs_devices->list, &fs_uuids);
379 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
380 fs_devices->latest_devid = devid;
381 fs_devices->latest_trans = found_transid;
e5e9a520 382 mutex_init(&fs_devices->device_list_mutex);
8a4b83cc
CM		 383 device = NULL;
384 } else {
a443755f
CM		 385 device = __find_device(&fs_devices->devices, devid,
386 disk_super->dev_item.uuid);
8a4b83cc
CM		 387 }
388 if (!device) {
2b82032c
YZ		 389 if (fs_devices->opened)
390 return -EBUSY;
391
8a4b83cc
CM		 392 device = kzalloc(sizeof(*device), GFP_NOFS);
393 if (!device) {
394 /* we can safely leave the fs_devices entry around */
395 return -ENOMEM;
396 }
397 device->devid = devid;
8b712842 398 device->work.func = pending_bios_fn;
a443755f
CM		 399 memcpy(device->uuid, disk_super->dev_item.uuid,
400 BTRFS_UUID_SIZE);
b248a415 401 spin_lock_init(&device->io_lock);
8a4b83cc
CM		 402 device->name = kstrdup(path, GFP_NOFS);
403 if (!device->name) {
404 kfree(device);
405 return -ENOMEM;
406 }
2b82032c 407 INIT_LIST_HEAD(&device->dev_alloc_list);
e5e9a520
CM		 408
409 mutex_lock(&fs_devices->device_list_mutex);
8a4b83cc 410 list_add(&device->dev_list, &fs_devices->devices);
e5e9a520
CM		 411 mutex_unlock(&fs_devices->device_list_mutex);
412
2b82032c 413 device->fs_devices = fs_devices;
8a4b83cc 414 fs_devices->num_devices++;
3a0524dc
TH		 415 } else if (strcmp(device->name, path)) {
416 name = kstrdup(path, GFP_NOFS);
417 if (!name)
418 return -ENOMEM;
419 kfree(device->name);
420 device->name = name;
8a4b83cc
CM		 421 }
422
423 if (found_transid > fs_devices->latest_trans) {
424 fs_devices->latest_devid = devid;
425 fs_devices->latest_trans = found_transid;
426 }
8a4b83cc
CM		 427 *fs_devices_ret = fs_devices;
428 return 0;
429}
430
e4404d6e
YZ		 431static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
432{
433 struct btrfs_fs_devices *fs_devices;
434 struct btrfs_device *device;
435 struct btrfs_device *orig_dev;
436
437 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
438 if (!fs_devices)
439 return ERR_PTR(-ENOMEM);
440
441 INIT_LIST_HEAD(&fs_devices->devices);
442 INIT_LIST_HEAD(&fs_devices->alloc_list);
443 INIT_LIST_HEAD(&fs_devices->list);
e5e9a520 444 mutex_init(&fs_devices->device_list_mutex);
e4404d6e
YZ		 445 fs_devices->latest_devid = orig->latest_devid;
446 fs_devices->latest_trans = orig->latest_trans;
447 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
448
e5e9a520 449 mutex_lock(&orig->device_list_mutex);
e4404d6e
YZ		 450 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
451 device = kzalloc(sizeof(*device), GFP_NOFS);
452 if (!device)
453 goto error;
454
455 device->name = kstrdup(orig_dev->name, GFP_NOFS);
fd2696f3
JL		 456 if (!device->name) {
457 kfree(device);
e4404d6e 458 goto error;
fd2696f3 459 }
e4404d6e
YZ		 460
461 device->devid = orig_dev->devid;
462 device->work.func = pending_bios_fn;
463 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
e4404d6e
YZ		 464 spin_lock_init(&device->io_lock);
465 INIT_LIST_HEAD(&device->dev_list);
466 INIT_LIST_HEAD(&device->dev_alloc_list);
467
468 list_add(&device->dev_list, &fs_devices->devices);
469 device->fs_devices = fs_devices;
470 fs_devices->num_devices++;
471 }
e5e9a520 472 mutex_unlock(&orig->device_list_mutex);
e4404d6e
YZ		 473 return fs_devices;
474error:
e5e9a520 475 mutex_unlock(&orig->device_list_mutex);
e4404d6e
YZ		 476 free_fs_devices(fs_devices);
477 return ERR_PTR(-ENOMEM);
478}
479
dfe25020
CM		 480int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
481{
c6e30871 482 struct btrfs_device *device, *next;
dfe25020
CM		 483
484 mutex_lock(&uuid_mutex);
485again:
e5e9a520 486 mutex_lock(&fs_devices->device_list_mutex);
c6e30871 487 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
2b82032c
YZ		 488 if (device->in_fs_metadata)
489 continue;
490
491 if (device->bdev) {
15916de8 492 close_bdev_exclusive(device->bdev, device->mode);
2b82032c
YZ		 493 device->bdev = NULL;
494 fs_devices->open_devices--;
495 }
496 if (device->writeable) {
497 list_del_init(&device->dev_alloc_list);
498 device->writeable = 0;
499 fs_devices->rw_devices--;
500 }
e4404d6e
YZ		 501 list_del_init(&device->dev_list);
502 fs_devices->num_devices--;
503 kfree(device->name);
504 kfree(device);
dfe25020 505 }
e5e9a520 506 mutex_unlock(&fs_devices->device_list_mutex);
2b82032c
YZ		 507
508 if (fs_devices->seed) {
509 fs_devices = fs_devices->seed;
2b82032c
YZ		 510 goto again;
511 }
512
dfe25020
CM		 513 mutex_unlock(&uuid_mutex);
514 return 0;
515}
a0af469b 516
2b82032c 517static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
8a4b83cc 518{
8a4b83cc 519 struct btrfs_device *device;
e4404d6e 520
2b82032c
YZ		 521 if (--fs_devices->opened > 0)
522 return 0;
8a4b83cc 523
c6e30871 524 list_for_each_entry(device, &fs_devices->devices, dev_list) {
8a4b83cc 525 if (device->bdev) {
15916de8 526 close_bdev_exclusive(device->bdev, device->mode);
a0af469b 527 fs_devices->open_devices--;
8a4b83cc 528 }
2b82032c
YZ		 529 if (device->writeable) {
530 list_del_init(&device->dev_alloc_list);
531 fs_devices->rw_devices--;
532 }
533
8a4b83cc 534 device->bdev = NULL;
2b82032c 535 device->writeable = 0;
dfe25020 536 device->in_fs_metadata = 0;
8a4b83cc 537 }
e4404d6e
YZ		 538 WARN_ON(fs_devices->open_devices);
539 WARN_ON(fs_devices->rw_devices);
2b82032c
YZ		 540 fs_devices->opened = 0;
541 fs_devices->seeding = 0;
2b82032c 542
8a4b83cc
CM		 543 return 0;
544}
545
2b82032c
YZ		 546int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
547{
e4404d6e 548 struct btrfs_fs_devices *seed_devices = NULL;
2b82032c
YZ		 549 int ret;
550
551 mutex_lock(&uuid_mutex);
552 ret = __btrfs_close_devices(fs_devices);
e4404d6e
YZ		 553 if (!fs_devices->opened) {
554 seed_devices = fs_devices->seed;
555 fs_devices->seed = NULL;
556 }
2b82032c 557 mutex_unlock(&uuid_mutex);
e4404d6e
YZ		 558
559 while (seed_devices) {
560 fs_devices = seed_devices;
561 seed_devices = fs_devices->seed;
562 __btrfs_close_devices(fs_devices);
563 free_fs_devices(fs_devices);
564 }
2b82032c
YZ		 565 return ret;
566}
567
e4404d6e
YZ		 568static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
569 fmode_t flags, void *holder)
8a4b83cc
CM		 570{
571 struct block_device *bdev;
572 struct list_head *head = &fs_devices->devices;
8a4b83cc 573 struct btrfs_device *device;
a0af469b
CM		 574 struct block_device *latest_bdev = NULL;
575 struct buffer_head *bh;
576 struct btrfs_super_block *disk_super;
577 u64 latest_devid = 0;
578 u64 latest_transid = 0;
a0af469b 579 u64 devid;
2b82032c 580 int seeding = 1;
a0af469b 581 int ret = 0;
8a4b83cc 582
c6e30871 583 list_for_each_entry(device, head, dev_list) {
c1c4d91c
CM		 584 if (device->bdev)
585 continue;
dfe25020
CM		 586 if (!device->name)
587 continue;
588
15916de8 589 bdev = open_bdev_exclusive(device->name, flags, holder);
8a4b83cc 590 if (IS_ERR(bdev)) {
d397712b 591 printk(KERN_INFO "open %s failed\n", device->name);
a0af469b 592 goto error;
8a4b83cc 593 }
a061fc8d 594 set_blocksize(bdev, 4096);
a0af469b 595
a512bbf8 596 bh = btrfs_read_dev_super(bdev);
a0af469b
CM		 597 if (!bh)
598 goto error_close;
599
600 disk_super = (struct btrfs_super_block *)bh->b_data;
a343832f 601 devid = btrfs_stack_device_id(&disk_super->dev_item);
a0af469b
CM		 602 if (devid != device->devid)
603 goto error_brelse;
604
2b82032c
YZ		 605 if (memcmp(device->uuid, disk_super->dev_item.uuid,
606 BTRFS_UUID_SIZE))
607 goto error_brelse;
608
609 device->generation = btrfs_super_generation(disk_super);
610 if (!latest_transid || device->generation > latest_transid) {
a0af469b 611 latest_devid = devid;
2b82032c 612 latest_transid = device->generation;
a0af469b
CM		 613 latest_bdev = bdev;
614 }
615
2b82032c
YZ		 616 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
617 device->writeable = 0;
618 } else {
619 device->writeable = !bdev_read_only(bdev);
620 seeding = 0;
621 }
622
8a4b83cc 623 device->bdev = bdev;
dfe25020 624 device->in_fs_metadata = 0;
15916de8
CM		 625 device->mode = flags;
626
c289811c
CM		 627 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
628 fs_devices->rotating = 1;
629
a0af469b 630 fs_devices->open_devices++;
2b82032c
YZ		 631 if (device->writeable) {
632 fs_devices->rw_devices++;
633 list_add(&device->dev_alloc_list,
634 &fs_devices->alloc_list);
635 }
a0af469b 636 continue;
a061fc8d 637
a0af469b
CM		 638error_brelse:
639 brelse(bh);
640error_close:
97288f2c 641 close_bdev_exclusive(bdev, FMODE_READ);
a0af469b
CM		 642error:
643 continue;
8a4b83cc 644 }
a0af469b
CM		 645 if (fs_devices->open_devices == 0) {
646 ret = -EIO;
647 goto out;
648 }
2b82032c
YZ		 649 fs_devices->seeding = seeding;
650 fs_devices->opened = 1;
a0af469b
CM		 651 fs_devices->latest_bdev = latest_bdev;
652 fs_devices->latest_devid = latest_devid;
653 fs_devices->latest_trans = latest_transid;
2b82032c 654 fs_devices->total_rw_bytes = 0;
a0af469b 655out:
2b82032c
YZ		 656 return ret;
657}
658
659int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
97288f2c 660 fmode_t flags, void *holder)
2b82032c
YZ		 661{
662 int ret;
663
664 mutex_lock(&uuid_mutex);
665 if (fs_devices->opened) {
e4404d6e
YZ		 666 fs_devices->opened++;
667 ret = 0;
2b82032c 668 } else {
15916de8 669 ret = __btrfs_open_devices(fs_devices, flags, holder);
2b82032c 670 }
8a4b83cc 671 mutex_unlock(&uuid_mutex);
8a4b83cc
CM		 672 return ret;
673}
674
97288f2c 675int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
8a4b83cc
CM		 676 struct btrfs_fs_devices **fs_devices_ret)
677{
678 struct btrfs_super_block *disk_super;
679 struct block_device *bdev;
680 struct buffer_head *bh;
681 int ret;
682 u64 devid;
f2984462 683 u64 transid;
8a4b83cc
CM		 684
685 mutex_lock(&uuid_mutex);
686
15916de8 687 bdev = open_bdev_exclusive(path, flags, holder);
8a4b83cc
CM		 688
689 if (IS_ERR(bdev)) {
8a4b83cc
CM		 690 ret = PTR_ERR(bdev);
691 goto error;
692 }
693
694 ret = set_blocksize(bdev, 4096);
695 if (ret)
696 goto error_close;
a512bbf8 697 bh = btrfs_read_dev_super(bdev);
8a4b83cc
CM		 698 if (!bh) {
699 ret = -EIO;
700 goto error_close;
701 }
702 disk_super = (struct btrfs_super_block *)bh->b_data;
a343832f 703 devid = btrfs_stack_device_id(&disk_super->dev_item);
f2984462 704 transid = btrfs_super_generation(disk_super);
7ae9c09d 705 if (disk_super->label[0])
d397712b 706 printk(KERN_INFO "device label %s ", disk_super->label);
7ae9c09d
CM		 707 else {
708 /* FIXME, make a readl uuid parser */
d397712b 709 printk(KERN_INFO "device fsid %llx-%llx ",
7ae9c09d
CM		 710 *(unsigned long long *)disk_super->fsid,
711 *(unsigned long long *)(disk_super->fsid + 8));
712 }
119e10cf 713 printk(KERN_CONT "devid %llu transid %llu %s\n",
d397712b 714 (unsigned long long)devid, (unsigned long long)transid, path);
8a4b83cc
CM		 715 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
716
8a4b83cc
CM		 717 brelse(bh);
718error_close:
15916de8 719 close_bdev_exclusive(bdev, flags);
8a4b83cc
CM		 720error:
721 mutex_unlock(&uuid_mutex);
722 return ret;
723}
0b86a832
CM		 724
725/*
726 * this uses a pretty simple search, the expectation is that it is
727 * called very infrequently and that a given device has a small number
728 * of extents
729 */
ba1bf481
JB		 730int find_free_dev_extent(struct btrfs_trans_handle *trans,
731 struct btrfs_device *device, u64 num_bytes,
732 u64 *start, u64 *max_avail)
0b86a832
CM		 733{
734 struct btrfs_key key;
735 struct btrfs_root *root = device->dev_root;
736 struct btrfs_dev_extent *dev_extent = NULL;
2b82032c 737 struct btrfs_path *path;
0b86a832
CM		 738 u64 hole_size = 0;
739 u64 last_byte = 0;
740 u64 search_start = 0;
741 u64 search_end = device->total_bytes;
742 int ret;
743 int slot = 0;
744 int start_found;
745 struct extent_buffer *l;
746
2b82032c
YZ		 747 path = btrfs_alloc_path();
748 if (!path)
749 return -ENOMEM;
0b86a832 750 path->reada = 2;
2b82032c 751 start_found = 0;
0b86a832
CM		 752
753 /* FIXME use last free of some kind */
754
8a4b83cc
CM		 755 /* we don't want to overwrite the superblock on the drive,
756 * so we make sure to start at an offset of at least 1MB
757 */
758 search_start = max((u64)1024 * 1024, search_start);
8f18cf13
CM		 759
760 if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
761 search_start = max(root->fs_info->alloc_start, search_start);
762
0b86a832
CM		 763 key.objectid = device->devid;
764 key.offset = search_start;
765 key.type = BTRFS_DEV_EXTENT_KEY;
766 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
767 if (ret < 0)
768 goto error;
1fcbac58
YZ		 769 if (ret > 0) {
770 ret = btrfs_previous_item(root, path, key.objectid, key.type);
771 if (ret < 0)
772 goto error;
773 if (ret > 0)
774 start_found = 1;
775 }
0b86a832
CM		 776 l = path->nodes[0];
777 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
778 while (1) {
779 l = path->nodes[0];
780 slot = path->slots[0];
781 if (slot >= btrfs_header_nritems(l)) {
782 ret = btrfs_next_leaf(root, path);
783 if (ret == 0)
784 continue;
785 if (ret < 0)
786 goto error;
787no_more_items:
788 if (!start_found) {
789 if (search_start >= search_end) {
790 ret = -ENOSPC;
791 goto error;
792 }
793 *start = search_start;
794 start_found = 1;
795 goto check_pending;
796 }
797 *start = last_byte > search_start ?
798 last_byte : search_start;
799 if (search_end <= *start) {
800 ret = -ENOSPC;
801 goto error;
802 }
803 goto check_pending;
804 }
805 btrfs_item_key_to_cpu(l, &key, slot);
806
807 if (key.objectid < device->devid)
808 goto next;
809
810 if (key.objectid > device->devid)
811 goto no_more_items;
812
813 if (key.offset >= search_start && key.offset > last_byte &&
814 start_found) {
815 if (last_byte < search_start)
816 last_byte = search_start;
817 hole_size = key.offset - last_byte;
9779b72f
CM		 818
819 if (hole_size > *max_avail)
820 *max_avail = hole_size;
821
0b86a832
CM		 822 if (key.offset > last_byte &&
823 hole_size >= num_bytes) {
824 *start = last_byte;
825 goto check_pending;
826 }
827 }
d397712b 828 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
0b86a832 829 goto next;
0b86a832
CM		 830
831 start_found = 1;
832 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
833 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
834next:
835 path->slots[0]++;
836 cond_resched();
837 }
838check_pending:
839 /* we have to make sure we didn't find an extent that has already
840 * been allocated by the map tree or the original allocation
841 */
0b86a832
CM		 842 BUG_ON(*start < search_start);
843
6324fbf3 844 if (*start + num_bytes > search_end) {
0b86a832
CM		 845 ret = -ENOSPC;
846 goto error;
847 }
848 /* check for pending inserts here */
2b82032c 849 ret = 0;
0b86a832
CM		 850
851error:
2b82032c 852 btrfs_free_path(path);
0b86a832
CM		 853 return ret;
854}
855
b2950863 856static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
8f18cf13
CM		 857 struct btrfs_device *device,
858 u64 start)
859{
860 int ret;
861 struct btrfs_path *path;
862 struct btrfs_root *root = device->dev_root;
863 struct btrfs_key key;
a061fc8d
CM		 864 struct btrfs_key found_key;
865 struct extent_buffer *leaf = NULL;
866 struct btrfs_dev_extent *extent = NULL;
8f18cf13
CM		 867
868 path = btrfs_alloc_path();
869 if (!path)
870 return -ENOMEM;
871
872 key.objectid = device->devid;
873 key.offset = start;
874 key.type = BTRFS_DEV_EXTENT_KEY;
875
876 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
a061fc8d
CM		 877 if (ret > 0) {
878 ret = btrfs_previous_item(root, path, key.objectid,
879 BTRFS_DEV_EXTENT_KEY);
880 BUG_ON(ret);
881 leaf = path->nodes[0];
882 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
883 extent = btrfs_item_ptr(leaf, path->slots[0],
884 struct btrfs_dev_extent);
885 BUG_ON(found_key.offset > start || found_key.offset +
886 btrfs_dev_extent_length(leaf, extent) < start);
887 ret = 0;
888 } else if (ret == 0) {
889 leaf = path->nodes[0];
890 extent = btrfs_item_ptr(leaf, path->slots[0],
891 struct btrfs_dev_extent);
892 }
8f18cf13
CM		 893 BUG_ON(ret);
894
dfe25020
CM		 895 if (device->bytes_used > 0)
896 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
8f18cf13
CM		 897 ret = btrfs_del_item(trans, root, path);
898 BUG_ON(ret);
899
900 btrfs_free_path(path);
901 return ret;
902}
903
2b82032c 904int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
0b86a832 905 struct btrfs_device *device,
e17cade2 906 u64 chunk_tree, u64 chunk_objectid,
2b82032c 907 u64 chunk_offset, u64 start, u64 num_bytes)
0b86a832
CM		 908{
909 int ret;
910 struct btrfs_path *path;
911 struct btrfs_root *root = device->dev_root;
912 struct btrfs_dev_extent *extent;
913 struct extent_buffer *leaf;
914 struct btrfs_key key;
915
dfe25020 916 WARN_ON(!device->in_fs_metadata);
0b86a832
CM		 917 path = btrfs_alloc_path();
918 if (!path)
919 return -ENOMEM;
920
0b86a832 921 key.objectid = device->devid;
2b82032c 922 key.offset = start;
0b86a832
CM		 923 key.type = BTRFS_DEV_EXTENT_KEY;
924 ret = btrfs_insert_empty_item(trans, root, path, &key,
925 sizeof(*extent));
926 BUG_ON(ret);
927
928 leaf = path->nodes[0];
929 extent = btrfs_item_ptr(leaf, path->slots[0],
930 struct btrfs_dev_extent);
e17cade2
CM		 931 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
932 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
933 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
934
935 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
936 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
937 BTRFS_UUID_SIZE);
938
0b86a832
CM		 939 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
940 btrfs_mark_buffer_dirty(leaf);
0b86a832
CM		 941 btrfs_free_path(path);
942 return ret;
943}
944
a1b32a59
CM		 945static noinline int find_next_chunk(struct btrfs_root *root,
946 u64 objectid, u64 *offset)
0b86a832
CM		 947{
948 struct btrfs_path *path;
949 int ret;
950 struct btrfs_key key;
e17cade2 951 struct btrfs_chunk *chunk;
0b86a832
CM		 952 struct btrfs_key found_key;
953
954 path = btrfs_alloc_path();
955 BUG_ON(!path);
956
e17cade2 957 key.objectid = objectid;
0b86a832
CM		 958 key.offset = (u64)-1;
959 key.type = BTRFS_CHUNK_ITEM_KEY;
960
961 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
962 if (ret < 0)
963 goto error;
964
965 BUG_ON(ret == 0);
966
967 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
968 if (ret) {
e17cade2 969 *offset = 0;
0b86a832
CM		 970 } else {
971 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
972 path->slots[0]);
e17cade2
CM		 973 if (found_key.objectid != objectid)
974 *offset = 0;
975 else {
976 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
977 struct btrfs_chunk);
978 *offset = found_key.offset +
979 btrfs_chunk_length(path->nodes[0], chunk);
980 }
0b86a832
CM		 981 }
982 ret = 0;
983error:
984 btrfs_free_path(path);
985 return ret;
986}
987
2b82032c 988static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
0b86a832
CM		 989{
990 int ret;
991 struct btrfs_key key;
992 struct btrfs_key found_key;
2b82032c
YZ		 993 struct btrfs_path *path;
994
995 root = root->fs_info->chunk_root;
996
997 path = btrfs_alloc_path();
998 if (!path)
999 return -ENOMEM;
0b86a832
CM		 1000
1001 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1002 key.type = BTRFS_DEV_ITEM_KEY;
1003 key.offset = (u64)-1;
1004
1005 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1006 if (ret < 0)
1007 goto error;
1008
1009 BUG_ON(ret == 0);
1010
1011 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1012 BTRFS_DEV_ITEM_KEY);
1013 if (ret) {
1014 *objectid = 1;
1015 } else {
1016 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1017 path->slots[0]);
1018 *objectid = found_key.offset + 1;
1019 }
1020 ret = 0;
1021error:
2b82032c 1022 btrfs_free_path(path);
0b86a832
CM		 1023 return ret;
1024}
1025
1026/*
1027 * the device information is stored in the chunk root
1028 * the btrfs_device struct should be fully filled in
1029 */
1030int btrfs_add_device(struct btrfs_trans_handle *trans,
1031 struct btrfs_root *root,
1032 struct btrfs_device *device)
1033{
1034 int ret;
1035 struct btrfs_path *path;
1036 struct btrfs_dev_item *dev_item;
1037 struct extent_buffer *leaf;
1038 struct btrfs_key key;
1039 unsigned long ptr;
0b86a832
CM		 1040
1041 root = root->fs_info->chunk_root;
1042
1043 path = btrfs_alloc_path();
1044 if (!path)
1045 return -ENOMEM;
1046
0b86a832
CM		 1047 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1048 key.type = BTRFS_DEV_ITEM_KEY;
2b82032c 1049 key.offset = device->devid;
0b86a832
CM		 1050
1051 ret = btrfs_insert_empty_item(trans, root, path, &key,
0d81ba5d 1052 sizeof(*dev_item));
0b86a832
CM		 1053 if (ret)
1054 goto out;
1055
1056 leaf = path->nodes[0];
1057 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1058
1059 btrfs_set_device_id(leaf, dev_item, device->devid);
2b82032c 1060 btrfs_set_device_generation(leaf, dev_item, 0);
0b86a832
CM		 1061 btrfs_set_device_type(leaf, dev_item, device->type);
1062 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1063 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1064 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
0b86a832
CM		 1065 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1066 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
e17cade2
CM		 1067 btrfs_set_device_group(leaf, dev_item, 0);
1068 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1069 btrfs_set_device_bandwidth(leaf, dev_item, 0);
c3027eb5 1070 btrfs_set_device_start_offset(leaf, dev_item, 0);
0b86a832 1071
0b86a832 1072 ptr = (unsigned long)btrfs_device_uuid(dev_item);
e17cade2 1073 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
2b82032c
YZ		 1074 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1075 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
0b86a832 1076 btrfs_mark_buffer_dirty(leaf);
0b86a832 1077
2b82032c 1078 ret = 0;
0b86a832
CM		 1079out:
1080 btrfs_free_path(path);
1081 return ret;
1082}
8f18cf13 1083
a061fc8d
CM		 1084static int btrfs_rm_dev_item(struct btrfs_root *root,
1085 struct btrfs_device *device)
1086{
1087 int ret;
1088 struct btrfs_path *path;
a061fc8d 1089 struct btrfs_key key;
a061fc8d
CM		 1090 struct btrfs_trans_handle *trans;
1091
1092 root = root->fs_info->chunk_root;
1093
1094 path = btrfs_alloc_path();
1095 if (!path)
1096 return -ENOMEM;
1097
a22285a6 1098 trans = btrfs_start_transaction(root, 0);
a061fc8d
CM		 1099 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1100 key.type = BTRFS_DEV_ITEM_KEY;
1101 key.offset = device->devid;
7d9eb12c 1102 lock_chunks(root);
a061fc8d
CM		 1103
1104 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1105 if (ret < 0)
1106 goto out;
1107
1108 if (ret > 0) {
1109 ret = -ENOENT;
1110 goto out;
1111 }
1112
1113 ret = btrfs_del_item(trans, root, path);
1114 if (ret)
1115 goto out;
a061fc8d
CM		 1116out:
1117 btrfs_free_path(path);
7d9eb12c 1118 unlock_chunks(root);
a061fc8d
CM		 1119 btrfs_commit_transaction(trans, root);
1120 return ret;
1121}
1122
1123int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1124{
1125 struct btrfs_device *device;
2b82032c 1126 struct btrfs_device *next_device;
a061fc8d 1127 struct block_device *bdev;
dfe25020 1128 struct buffer_head *bh = NULL;
a061fc8d
CM		 1129 struct btrfs_super_block *disk_super;
1130 u64 all_avail;
1131 u64 devid;
2b82032c
YZ		 1132 u64 num_devices;
1133 u8 *dev_uuid;
a061fc8d
CM		 1134 int ret = 0;
1135
a061fc8d 1136 mutex_lock(&uuid_mutex);
7d9eb12c 1137 mutex_lock(&root->fs_info->volume_mutex);
a061fc8d
CM		 1138
1139 all_avail = root->fs_info->avail_data_alloc_bits |
1140 root->fs_info->avail_system_alloc_bits |
1141 root->fs_info->avail_metadata_alloc_bits;
1142
1143 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
035fe03a 1144 root->fs_info->fs_devices->num_devices <= 4) {
d397712b
CM		 1145 printk(KERN_ERR "btrfs: unable to go below four devices "
1146 "on raid10\n");
a061fc8d
CM		 1147 ret = -EINVAL;
1148 goto out;
1149 }
1150
1151 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
035fe03a 1152 root->fs_info->fs_devices->num_devices <= 2) {
d397712b
CM		 1153 printk(KERN_ERR "btrfs: unable to go below two "
1154 "devices on raid1\n");
a061fc8d
CM		 1155 ret = -EINVAL;
1156 goto out;
1157 }
1158
dfe25020 1159 if (strcmp(device_path, "missing") == 0) {
dfe25020
CM		 1160 struct list_head *devices;
1161 struct btrfs_device *tmp;
a061fc8d 1162
dfe25020
CM		 1163 device = NULL;
1164 devices = &root->fs_info->fs_devices->devices;
e5e9a520 1165 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
c6e30871 1166 list_for_each_entry(tmp, devices, dev_list) {
dfe25020
CM		 1167 if (tmp->in_fs_metadata && !tmp->bdev) {
1168 device = tmp;
1169 break;
1170 }
1171 }
e5e9a520 1172 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
dfe25020
CM		 1173 bdev = NULL;
1174 bh = NULL;
1175 disk_super = NULL;
1176 if (!device) {
d397712b
CM		 1177 printk(KERN_ERR "btrfs: no missing devices found to "
1178 "remove\n");
dfe25020
CM		 1179 goto out;
1180 }
dfe25020 1181 } else {
97288f2c 1182 bdev = open_bdev_exclusive(device_path, FMODE_READ,
dfe25020
CM		 1183 root->fs_info->bdev_holder);
1184 if (IS_ERR(bdev)) {
1185 ret = PTR_ERR(bdev);
1186 goto out;
1187 }
a061fc8d 1188
2b82032c 1189 set_blocksize(bdev, 4096);
a512bbf8 1190 bh = btrfs_read_dev_super(bdev);
dfe25020
CM		 1191 if (!bh) {
1192 ret = -EIO;
1193 goto error_close;
1194 }
1195 disk_super = (struct btrfs_super_block *)bh->b_data;
a343832f 1196 devid = btrfs_stack_device_id(&disk_super->dev_item);
2b82032c
YZ		 1197 dev_uuid = disk_super->dev_item.uuid;
1198 device = btrfs_find_device(root, devid, dev_uuid,
1199 disk_super->fsid);
dfe25020
CM		 1200 if (!device) {
1201 ret = -ENOENT;
1202 goto error_brelse;
1203 }
2b82032c 1204 }
dfe25020 1205
2b82032c 1206 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
d397712b
CM		 1207 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1208 "device\n");
2b82032c
YZ		 1209 ret = -EINVAL;
1210 goto error_brelse;
1211 }
1212
1213 if (device->writeable) {
1214 list_del_init(&device->dev_alloc_list);
1215 root->fs_info->fs_devices->rw_devices--;
dfe25020 1216 }
a061fc8d
CM		 1217
1218 ret = btrfs_shrink_device(device, 0);
1219 if (ret)
1220 goto error_brelse;
1221
a061fc8d
CM		 1222 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1223 if (ret)
1224 goto error_brelse;
1225
2b82032c 1226 device->in_fs_metadata = 0;
e5e9a520
CM		 1227
1228 /*
1229 * the device list mutex makes sure that we don't change
1230 * the device list while someone else is writing out all
1231 * the device supers.
1232 */
1233 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
e4404d6e 1234 list_del_init(&device->dev_list);
e5e9a520
CM		 1235 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1236
e4404d6e 1237 device->fs_devices->num_devices--;
2b82032c
YZ		 1238
1239 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1240 struct btrfs_device, dev_list);
1241 if (device->bdev == root->fs_info->sb->s_bdev)
1242 root->fs_info->sb->s_bdev = next_device->bdev;
1243 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1244 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1245
e4404d6e
YZ		 1246 if (device->bdev) {
1247 close_bdev_exclusive(device->bdev, device->mode);
1248 device->bdev = NULL;
1249 device->fs_devices->open_devices--;
1250 }
1251
2b82032c
YZ		 1252 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1253 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1254
e4404d6e
YZ		 1255 if (device->fs_devices->open_devices == 0) {
1256 struct btrfs_fs_devices *fs_devices;
1257 fs_devices = root->fs_info->fs_devices;
1258 while (fs_devices) {
1259 if (fs_devices->seed == device->fs_devices)
1260 break;
1261 fs_devices = fs_devices->seed;
2b82032c 1262 }
e4404d6e
YZ		 1263 fs_devices->seed = device->fs_devices->seed;
1264 device->fs_devices->seed = NULL;
1265 __btrfs_close_devices(device->fs_devices);
1266 free_fs_devices(device->fs_devices);
2b82032c
YZ		 1267 }
1268
1269 /*
1270 * at this point, the device is zero sized. We want to
1271 * remove it from the devices list and zero out the old super
1272 */
1273 if (device->writeable) {
dfe25020
CM		 1274 /* make sure this device isn't detected as part of
1275 * the FS anymore
1276 */
1277 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1278 set_buffer_dirty(bh);
1279 sync_dirty_buffer(bh);
dfe25020 1280 }
a061fc8d
CM		 1281
1282 kfree(device->name);
1283 kfree(device);
1284 ret = 0;
a061fc8d
CM		 1285
1286error_brelse:
1287 brelse(bh);
1288error_close:
dfe25020 1289 if (bdev)
97288f2c 1290 close_bdev_exclusive(bdev, FMODE_READ);
a061fc8d 1291out:
7d9eb12c 1292 mutex_unlock(&root->fs_info->volume_mutex);
a061fc8d 1293 mutex_unlock(&uuid_mutex);
a061fc8d
CM		 1294 return ret;
1295}
1296
2b82032c
YZ		 1297/*
1298 * does all the dirty work required for changing file system's UUID.
1299 */
1300static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1301 struct btrfs_root *root)
1302{
1303 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1304 struct btrfs_fs_devices *old_devices;
e4404d6e 1305 struct btrfs_fs_devices *seed_devices;
2b82032c
YZ		 1306 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1307 struct btrfs_device *device;
1308 u64 super_flags;
1309
1310 BUG_ON(!mutex_is_locked(&uuid_mutex));
e4404d6e 1311 if (!fs_devices->seeding)
2b82032c
YZ		 1312 return -EINVAL;
1313
e4404d6e
YZ		 1314 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1315 if (!seed_devices)
2b82032c
YZ		 1316 return -ENOMEM;
1317
e4404d6e
YZ		 1318 old_devices = clone_fs_devices(fs_devices);
1319 if (IS_ERR(old_devices)) {
1320 kfree(seed_devices);
1321 return PTR_ERR(old_devices);
2b82032c 1322 }
e4404d6e 1323
2b82032c
YZ		 1324 list_add(&old_devices->list, &fs_uuids);
1325
e4404d6e
YZ		 1326 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1327 seed_devices->opened = 1;
1328 INIT_LIST_HEAD(&seed_devices->devices);
1329 INIT_LIST_HEAD(&seed_devices->alloc_list);
e5e9a520 1330 mutex_init(&seed_devices->device_list_mutex);
e4404d6e
YZ		 1331 list_splice_init(&fs_devices->devices, &seed_devices->devices);
1332 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1333 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1334 device->fs_devices = seed_devices;
1335 }
1336
2b82032c
YZ		 1337 fs_devices->seeding = 0;
1338 fs_devices->num_devices = 0;
1339 fs_devices->open_devices = 0;
e4404d6e 1340 fs_devices->seed = seed_devices;
2b82032c
YZ		 1341
1342 generate_random_uuid(fs_devices->fsid);
1343 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1344 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1345 super_flags = btrfs_super_flags(disk_super) &
1346 ~BTRFS_SUPER_FLAG_SEEDING;
1347 btrfs_set_super_flags(disk_super, super_flags);
1348
1349 return 0;
1350}
1351
1352/*
1353 * strore the expected generation for seed devices in device items.
1354 */
1355static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1356 struct btrfs_root *root)
1357{
1358 struct btrfs_path *path;
1359 struct extent_buffer *leaf;
1360 struct btrfs_dev_item *dev_item;
1361 struct btrfs_device *device;
1362 struct btrfs_key key;
1363 u8 fs_uuid[BTRFS_UUID_SIZE];
1364 u8 dev_uuid[BTRFS_UUID_SIZE];
1365 u64 devid;
1366 int ret;
1367
1368 path = btrfs_alloc_path();
1369 if (!path)
1370 return -ENOMEM;
1371
1372 root = root->fs_info->chunk_root;
1373 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1374 key.offset = 0;
1375 key.type = BTRFS_DEV_ITEM_KEY;
1376
1377 while (1) {
1378 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1379 if (ret < 0)
1380 goto error;
1381
1382 leaf = path->nodes[0];
1383next_slot:
1384 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1385 ret = btrfs_next_leaf(root, path);
1386 if (ret > 0)
1387 break;
1388 if (ret < 0)
1389 goto error;
1390 leaf = path->nodes[0];
1391 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1392 btrfs_release_path(root, path);
1393 continue;
1394 }
1395
1396 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1397 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1398 key.type != BTRFS_DEV_ITEM_KEY)
1399 break;
1400
1401 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1402 struct btrfs_dev_item);
1403 devid = btrfs_device_id(leaf, dev_item);
1404 read_extent_buffer(leaf, dev_uuid,
1405 (unsigned long)btrfs_device_uuid(dev_item),
1406 BTRFS_UUID_SIZE);
1407 read_extent_buffer(leaf, fs_uuid,
1408 (unsigned long)btrfs_device_fsid(dev_item),
1409 BTRFS_UUID_SIZE);
1410 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1411 BUG_ON(!device);
1412
1413 if (device->fs_devices->seeding) {
1414 btrfs_set_device_generation(leaf, dev_item,
1415 device->generation);
1416 btrfs_mark_buffer_dirty(leaf);
1417 }
1418
1419 path->slots[0]++;
1420 goto next_slot;
1421 }
1422 ret = 0;
1423error:
1424 btrfs_free_path(path);
1425 return ret;
1426}
1427
788f20eb
CM		 1428int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1429{
1430 struct btrfs_trans_handle *trans;
1431 struct btrfs_device *device;
1432 struct block_device *bdev;
788f20eb 1433 struct list_head *devices;
2b82032c 1434 struct super_block *sb = root->fs_info->sb;
788f20eb 1435 u64 total_bytes;
2b82032c 1436 int seeding_dev = 0;
788f20eb
CM		 1437 int ret = 0;
1438
2b82032c
YZ		 1439 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1440 return -EINVAL;
788f20eb 1441
15916de8 1442 bdev = open_bdev_exclusive(device_path, 0, root->fs_info->bdev_holder);
7f59203a
JB		 1443 if (IS_ERR(bdev))
1444 return PTR_ERR(bdev);
a2135011 1445
2b82032c
YZ		 1446 if (root->fs_info->fs_devices->seeding) {
1447 seeding_dev = 1;
1448 down_write(&sb->s_umount);
1449 mutex_lock(&uuid_mutex);
1450 }
1451
8c8bee1d 1452 filemap_write_and_wait(bdev->bd_inode->i_mapping);
7d9eb12c 1453 mutex_lock(&root->fs_info->volume_mutex);
a2135011 1454
788f20eb 1455 devices = &root->fs_info->fs_devices->devices;
e5e9a520
CM		 1456 /*
1457 * we have the volume lock, so we don't need the extra
1458 * device list mutex while reading the list here.
1459 */
c6e30871 1460 list_for_each_entry(device, devices, dev_list) {
788f20eb
CM		 1461 if (device->bdev == bdev) {
1462 ret = -EEXIST;
2b82032c 1463 goto error;
788f20eb
CM		 1464 }
1465 }
1466
1467 device = kzalloc(sizeof(*device), GFP_NOFS);
1468 if (!device) {
1469 /* we can safely leave the fs_devices entry around */
1470 ret = -ENOMEM;
2b82032c 1471 goto error;
788f20eb
CM		 1472 }
1473
788f20eb
CM		 1474 device->name = kstrdup(device_path, GFP_NOFS);
1475 if (!device->name) {
1476 kfree(device);
2b82032c
YZ		 1477 ret = -ENOMEM;
1478 goto error;
788f20eb 1479 }
2b82032c
YZ		 1480
1481 ret = find_next_devid(root, &device->devid);
1482 if (ret) {
1483 kfree(device);
1484 goto error;
1485 }
1486
a22285a6 1487 trans = btrfs_start_transaction(root, 0);
2b82032c
YZ		 1488 lock_chunks(root);
1489
2b82032c
YZ		 1490 device->writeable = 1;
1491 device->work.func = pending_bios_fn;
1492 generate_random_uuid(device->uuid);
1493 spin_lock_init(&device->io_lock);
1494 device->generation = trans->transid;
788f20eb
CM		 1495 device->io_width = root->sectorsize;
1496 device->io_align = root->sectorsize;
1497 device->sector_size = root->sectorsize;
1498 device->total_bytes = i_size_read(bdev->bd_inode);
2cc3c559 1499 device->disk_total_bytes = device->total_bytes;
788f20eb
CM		 1500 device->dev_root = root->fs_info->dev_root;
1501 device->bdev = bdev;
dfe25020 1502 device->in_fs_metadata = 1;
15916de8 1503 device->mode = 0;
2b82032c 1504 set_blocksize(device->bdev, 4096);
788f20eb 1505
2b82032c
YZ		 1506 if (seeding_dev) {
1507 sb->s_flags &= ~MS_RDONLY;
1508 ret = btrfs_prepare_sprout(trans, root);
1509 BUG_ON(ret);
1510 }
788f20eb 1511
2b82032c 1512 device->fs_devices = root->fs_info->fs_devices;
e5e9a520
CM		 1513
1514 /*
1515 * we don't want write_supers to jump in here with our device
1516 * half setup
1517 */
1518 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2b82032c
YZ		 1519 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1520 list_add(&device->dev_alloc_list,
1521 &root->fs_info->fs_devices->alloc_list);
1522 root->fs_info->fs_devices->num_devices++;
1523 root->fs_info->fs_devices->open_devices++;
1524 root->fs_info->fs_devices->rw_devices++;
1525 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
325cd4ba 1526
c289811c
CM		 1527 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1528 root->fs_info->fs_devices->rotating = 1;
1529
788f20eb
CM		 1530 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1531 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1532 total_bytes + device->total_bytes);
1533
1534 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1535 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1536 total_bytes + 1);
e5e9a520 1537 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
788f20eb 1538
2b82032c
YZ		 1539 if (seeding_dev) {
1540 ret = init_first_rw_device(trans, root, device);
1541 BUG_ON(ret);
1542 ret = btrfs_finish_sprout(trans, root);
1543 BUG_ON(ret);
1544 } else {
1545 ret = btrfs_add_device(trans, root, device);
1546 }
1547
913d952e
CM		 1548 /*
1549 * we've got more storage, clear any full flags on the space
1550 * infos
1551 */
1552 btrfs_clear_space_info_full(root->fs_info);
1553
7d9eb12c 1554 unlock_chunks(root);
2b82032c 1555 btrfs_commit_transaction(trans, root);
a2135011 1556
2b82032c
YZ		 1557 if (seeding_dev) {
1558 mutex_unlock(&uuid_mutex);
1559 up_write(&sb->s_umount);
788f20eb 1560
2b82032c
YZ		 1561 ret = btrfs_relocate_sys_chunks(root);
1562 BUG_ON(ret);
1563 }
1564out:
1565 mutex_unlock(&root->fs_info->volume_mutex);
1566 return ret;
1567error:
15916de8 1568 close_bdev_exclusive(bdev, 0);
2b82032c
YZ		 1569 if (seeding_dev) {
1570 mutex_unlock(&uuid_mutex);
1571 up_write(&sb->s_umount);
1572 }
788f20eb
CM		 1573 goto out;
1574}
1575
d397712b
CM		 1576static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1577 struct btrfs_device *device)
0b86a832
CM		 1578{
1579 int ret;
1580 struct btrfs_path *path;
1581 struct btrfs_root *root;
1582 struct btrfs_dev_item *dev_item;
1583 struct extent_buffer *leaf;
1584 struct btrfs_key key;
1585
1586 root = device->dev_root->fs_info->chunk_root;
1587
1588 path = btrfs_alloc_path();
1589 if (!path)
1590 return -ENOMEM;
1591
1592 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1593 key.type = BTRFS_DEV_ITEM_KEY;
1594 key.offset = device->devid;
1595
1596 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1597 if (ret < 0)
1598 goto out;
1599
1600 if (ret > 0) {
1601 ret = -ENOENT;
1602 goto out;
1603 }
1604
1605 leaf = path->nodes[0];
1606 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1607
1608 btrfs_set_device_id(leaf, dev_item, device->devid);
1609 btrfs_set_device_type(leaf, dev_item, device->type);
1610 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1611 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1612 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
d6397bae 1613 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
0b86a832
CM		 1614 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1615 btrfs_mark_buffer_dirty(leaf);
1616
1617out:
1618 btrfs_free_path(path);
1619 return ret;
1620}
1621
7d9eb12c 1622static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
8f18cf13
CM		 1623 struct btrfs_device *device, u64 new_size)
1624{
1625 struct btrfs_super_block *super_copy =
1626 &device->dev_root->fs_info->super_copy;
1627 u64 old_total = btrfs_super_total_bytes(super_copy);
1628 u64 diff = new_size - device->total_bytes;
1629
2b82032c
YZ		 1630 if (!device->writeable)
1631 return -EACCES;
1632 if (new_size <= device->total_bytes)
1633 return -EINVAL;
1634
8f18cf13 1635 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2b82032c
YZ		 1636 device->fs_devices->total_rw_bytes += diff;
1637
1638 device->total_bytes = new_size;
9779b72f 1639 device->disk_total_bytes = new_size;
4184ea7f
CM		 1640 btrfs_clear_space_info_full(device->dev_root->fs_info);
1641
8f18cf13
CM		 1642 return btrfs_update_device(trans, device);
1643}
1644
7d9eb12c
CM		 1645int btrfs_grow_device(struct btrfs_trans_handle *trans,
1646 struct btrfs_device *device, u64 new_size)
1647{
1648 int ret;
1649 lock_chunks(device->dev_root);
1650 ret = __btrfs_grow_device(trans, device, new_size);
1651 unlock_chunks(device->dev_root);
1652 return ret;
1653}
1654
8f18cf13
CM		 1655static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1656 struct btrfs_root *root,
1657 u64 chunk_tree, u64 chunk_objectid,
1658 u64 chunk_offset)
1659{
1660 int ret;
1661 struct btrfs_path *path;
1662 struct btrfs_key key;
1663
1664 root = root->fs_info->chunk_root;
1665 path = btrfs_alloc_path();
1666 if (!path)
1667 return -ENOMEM;
1668
1669 key.objectid = chunk_objectid;
1670 key.offset = chunk_offset;
1671 key.type = BTRFS_CHUNK_ITEM_KEY;
1672
1673 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1674 BUG_ON(ret);
1675
1676 ret = btrfs_del_item(trans, root, path);
1677 BUG_ON(ret);
1678
1679 btrfs_free_path(path);
1680 return 0;
1681}
1682
b2950863 1683static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
8f18cf13
CM		 1684 chunk_offset)
1685{
1686 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1687 struct btrfs_disk_key *disk_key;
1688 struct btrfs_chunk *chunk;
1689 u8 *ptr;
1690 int ret = 0;
1691 u32 num_stripes;
1692 u32 array_size;
1693 u32 len = 0;
1694 u32 cur;
1695 struct btrfs_key key;
1696
1697 array_size = btrfs_super_sys_array_size(super_copy);
1698
1699 ptr = super_copy->sys_chunk_array;
1700 cur = 0;
1701
1702 while (cur < array_size) {
1703 disk_key = (struct btrfs_disk_key *)ptr;
1704 btrfs_disk_key_to_cpu(&key, disk_key);
1705
1706 len = sizeof(*disk_key);
1707
1708 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1709 chunk = (struct btrfs_chunk *)(ptr + len);
1710 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1711 len += btrfs_chunk_item_size(num_stripes);
1712 } else {
1713 ret = -EIO;
1714 break;
1715 }
1716 if (key.objectid == chunk_objectid &&
1717 key.offset == chunk_offset) {
1718 memmove(ptr, ptr + len, array_size - (cur + len));
1719 array_size -= len;
1720 btrfs_set_super_sys_array_size(super_copy, array_size);
1721 } else {
1722 ptr += len;
1723 cur += len;
1724 }
1725 }
1726 return ret;
1727}
1728
b2950863 1729static int btrfs_relocate_chunk(struct btrfs_root *root,
8f18cf13
CM		 1730 u64 chunk_tree, u64 chunk_objectid,
1731 u64 chunk_offset)
1732{
1733 struct extent_map_tree *em_tree;
1734 struct btrfs_root *extent_root;
1735 struct btrfs_trans_handle *trans;
1736 struct extent_map *em;
1737 struct map_lookup *map;
1738 int ret;
1739 int i;
1740
1741 root = root->fs_info->chunk_root;
1742 extent_root = root->fs_info->extent_root;
1743 em_tree = &root->fs_info->mapping_tree.map_tree;
1744
ba1bf481
JB		 1745 ret = btrfs_can_relocate(extent_root, chunk_offset);
1746 if (ret)
1747 return -ENOSPC;
1748
8f18cf13 1749 /* step one, relocate all the extents inside this chunk */
1a40e23b 1750 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
a22285a6
YZ		 1751 if (ret)
1752 return ret;
8f18cf13 1753
a22285a6 1754 trans = btrfs_start_transaction(root, 0);
8f18cf13
CM		 1755 BUG_ON(!trans);
1756
7d9eb12c
CM		 1757 lock_chunks(root);
1758
8f18cf13
CM		 1759 /*
1760 * step two, delete the device extents and the
1761 * chunk tree entries
1762 */
890871be 1763 read_lock(&em_tree->lock);
8f18cf13 1764 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
890871be 1765 read_unlock(&em_tree->lock);
8f18cf13 1766
a061fc8d
CM		 1767 BUG_ON(em->start > chunk_offset ||
1768 em->start + em->len < chunk_offset);
8f18cf13
CM		 1769 map = (struct map_lookup *)em->bdev;
1770
1771 for (i = 0; i < map->num_stripes; i++) {
1772 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1773 map->stripes[i].physical);
1774 BUG_ON(ret);
a061fc8d 1775
dfe25020
CM		 1776 if (map->stripes[i].dev) {
1777 ret = btrfs_update_device(trans, map->stripes[i].dev);
1778 BUG_ON(ret);
1779 }
8f18cf13
CM		 1780 }
1781 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1782 chunk_offset);
1783
1784 BUG_ON(ret);
1785
1786 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1787 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1788 BUG_ON(ret);
8f18cf13
CM		 1789 }
1790
2b82032c
YZ		 1791 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1792 BUG_ON(ret);
1793
890871be 1794 write_lock(&em_tree->lock);
2b82032c 1795 remove_extent_mapping(em_tree, em);
890871be 1796 write_unlock(&em_tree->lock);
2b82032c
YZ		 1797
1798 kfree(map);
1799 em->bdev = NULL;
1800
1801 /* once for the tree */
1802 free_extent_map(em);
1803 /* once for us */
1804 free_extent_map(em);
1805
1806 unlock_chunks(root);
1807 btrfs_end_transaction(trans, root);
1808 return 0;
1809}
1810
1811static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1812{
1813 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1814 struct btrfs_path *path;
1815 struct extent_buffer *leaf;
1816 struct btrfs_chunk *chunk;
1817 struct btrfs_key key;
1818 struct btrfs_key found_key;
1819 u64 chunk_tree = chunk_root->root_key.objectid;
1820 u64 chunk_type;
ba1bf481
JB		 1821 bool retried = false;
1822 int failed = 0;
2b82032c
YZ		 1823 int ret;
1824
1825 path = btrfs_alloc_path();
1826 if (!path)
1827 return -ENOMEM;
1828
ba1bf481 1829again:
2b82032c
YZ		 1830 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1831 key.offset = (u64)-1;
1832 key.type = BTRFS_CHUNK_ITEM_KEY;
1833
1834 while (1) {
1835 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1836 if (ret < 0)
1837 goto error;
1838 BUG_ON(ret == 0);
1839
1840 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1841 key.type);
1842 if (ret < 0)
1843 goto error;
1844 if (ret > 0)
1845 break;
1a40e23b 1846
2b82032c
YZ		 1847 leaf = path->nodes[0];
1848 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1a40e23b 1849
2b82032c
YZ		 1850 chunk = btrfs_item_ptr(leaf, path->slots[0],
1851 struct btrfs_chunk);
1852 chunk_type = btrfs_chunk_type(leaf, chunk);
1853 btrfs_release_path(chunk_root, path);
8f18cf13 1854
2b82032c
YZ		 1855 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1856 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1857 found_key.objectid,
1858 found_key.offset);
ba1bf481
JB		 1859 if (ret == -ENOSPC)
1860 failed++;
1861 else if (ret)
1862 BUG();
2b82032c 1863 }
8f18cf13 1864
2b82032c
YZ		 1865 if (found_key.offset == 0)
1866 break;
1867 key.offset = found_key.offset - 1;
1868 }
1869 ret = 0;
ba1bf481
JB		 1870 if (failed && !retried) {
1871 failed = 0;
1872 retried = true;
1873 goto again;
1874 } else if (failed && retried) {
1875 WARN_ON(1);
1876 ret = -ENOSPC;
1877 }
2b82032c
YZ		 1878error:
1879 btrfs_free_path(path);
1880 return ret;
8f18cf13
CM		 1881}
1882
ec44a35c
CM		 1883static u64 div_factor(u64 num, int factor)
1884{
1885 if (factor == 10)
1886 return num;
1887 num *= factor;
1888 do_div(num, 10);
1889 return num;
1890}
1891
ec44a35c
CM		 1892int btrfs_balance(struct btrfs_root *dev_root)
1893{
1894 int ret;
ec44a35c
CM		 1895 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
1896 struct btrfs_device *device;
1897 u64 old_size;
1898 u64 size_to_free;
1899 struct btrfs_path *path;
1900 struct btrfs_key key;
ec44a35c
CM		 1901 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
1902 struct btrfs_trans_handle *trans;
1903 struct btrfs_key found_key;
1904
2b82032c
YZ		 1905 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
1906 return -EROFS;
ec44a35c 1907
7d9eb12c 1908 mutex_lock(&dev_root->fs_info->volume_mutex);
ec44a35c
CM		 1909 dev_root = dev_root->fs_info->dev_root;
1910
ec44a35c 1911 /* step one make some room on all the devices */
c6e30871 1912 list_for_each_entry(device, devices, dev_list) {
ec44a35c
CM		 1913 old_size = device->total_bytes;
1914 size_to_free = div_factor(old_size, 1);
1915 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2b82032c
YZ		 1916 if (!device->writeable ||
1917 device->total_bytes - device->bytes_used > size_to_free)
ec44a35c
CM		 1918 continue;
1919
1920 ret = btrfs_shrink_device(device, old_size - size_to_free);
ba1bf481
JB		 1921 if (ret == -ENOSPC)
1922 break;
ec44a35c
CM		 1923 BUG_ON(ret);
1924
a22285a6 1925 trans = btrfs_start_transaction(dev_root, 0);
ec44a35c
CM		 1926 BUG_ON(!trans);
1927
1928 ret = btrfs_grow_device(trans, device, old_size);
1929 BUG_ON(ret);
1930
1931 btrfs_end_transaction(trans, dev_root);
1932 }
1933
1934 /* step two, relocate all the chunks */
1935 path = btrfs_alloc_path();
1936 BUG_ON(!path);
1937
1938 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1939 key.offset = (u64)-1;
1940 key.type = BTRFS_CHUNK_ITEM_KEY;
1941
d397712b 1942 while (1) {
ec44a35c
CM		 1943 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1944 if (ret < 0)
1945 goto error;
1946
1947 /*
1948 * this shouldn't happen, it means the last relocate
1949 * failed
1950 */
1951 if (ret == 0)
1952 break;
1953
1954 ret = btrfs_previous_item(chunk_root, path, 0,
1955 BTRFS_CHUNK_ITEM_KEY);
7d9eb12c 1956 if (ret)
ec44a35c 1957 break;
7d9eb12c 1958
ec44a35c
CM		 1959 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1960 path->slots[0]);
1961 if (found_key.objectid != key.objectid)
1962 break;
7d9eb12c 1963
ec44a35c 1964 /* chunk zero is special */
ba1bf481 1965 if (found_key.offset == 0)
ec44a35c
CM		 1966 break;
1967
7d9eb12c 1968 btrfs_release_path(chunk_root, path);
ec44a35c
CM		 1969 ret = btrfs_relocate_chunk(chunk_root,
1970 chunk_root->root_key.objectid,
1971 found_key.objectid,
1972 found_key.offset);
ba1bf481
JB		 1973 BUG_ON(ret && ret != -ENOSPC);
1974 key.offset = found_key.offset - 1;
ec44a35c
CM		 1975 }
1976 ret = 0;
1977error:
1978 btrfs_free_path(path);
7d9eb12c 1979 mutex_unlock(&dev_root->fs_info->volume_mutex);
ec44a35c
CM		 1980 return ret;
1981}
1982
8f18cf13
CM		 1983/*
1984 * shrinking a device means finding all of the device extents past
1985 * the new size, and then following the back refs to the chunks.
1986 * The chunk relocation code actually frees the device extent
1987 */
1988int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
1989{
1990 struct btrfs_trans_handle *trans;
1991 struct btrfs_root *root = device->dev_root;
1992 struct btrfs_dev_extent *dev_extent = NULL;
1993 struct btrfs_path *path;
1994 u64 length;
1995 u64 chunk_tree;
1996 u64 chunk_objectid;
1997 u64 chunk_offset;
1998 int ret;
1999 int slot;
ba1bf481
JB		 2000 int failed = 0;
2001 bool retried = false;
8f18cf13
CM		 2002 struct extent_buffer *l;
2003 struct btrfs_key key;
2004 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2005 u64 old_total = btrfs_super_total_bytes(super_copy);
ba1bf481 2006 u64 old_size = device->total_bytes;
8f18cf13
CM		 2007 u64 diff = device->total_bytes - new_size;
2008
2b82032c
YZ		 2009 if (new_size >= device->total_bytes)
2010 return -EINVAL;
8f18cf13
CM		 2011
2012 path = btrfs_alloc_path();
2013 if (!path)
2014 return -ENOMEM;
2015
8f18cf13
CM		 2016 path->reada = 2;
2017
7d9eb12c
CM		 2018 lock_chunks(root);
2019
8f18cf13 2020 device->total_bytes = new_size;
2b82032c
YZ		 2021 if (device->writeable)
2022 device->fs_devices->total_rw_bytes -= diff;
7d9eb12c 2023 unlock_chunks(root);
8f18cf13 2024
ba1bf481 2025again:
8f18cf13
CM		 2026 key.objectid = device->devid;
2027 key.offset = (u64)-1;
2028 key.type = BTRFS_DEV_EXTENT_KEY;
2029
2030 while (1) {
2031 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2032 if (ret < 0)
2033 goto done;
2034
2035 ret = btrfs_previous_item(root, path, 0, key.type);
2036 if (ret < 0)
2037 goto done;
2038 if (ret) {
2039 ret = 0;
ba1bf481 2040 btrfs_release_path(root, path);
bf1fb512 2041 break;
8f18cf13
CM		 2042 }
2043
2044 l = path->nodes[0];
2045 slot = path->slots[0];
2046 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2047
ba1bf481
JB		 2048 if (key.objectid != device->devid) {
2049 btrfs_release_path(root, path);
bf1fb512 2050 break;
ba1bf481 2051 }
8f18cf13
CM		 2052
2053 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2054 length = btrfs_dev_extent_length(l, dev_extent);
2055
ba1bf481
JB		 2056 if (key.offset + length <= new_size) {
2057 btrfs_release_path(root, path);
d6397bae 2058 break;
ba1bf481 2059 }
8f18cf13
CM		 2060
2061 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2062 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2063 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2064 btrfs_release_path(root, path);
2065
2066 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2067 chunk_offset);
ba1bf481 2068 if (ret && ret != -ENOSPC)
8f18cf13 2069 goto done;
ba1bf481
JB		 2070 if (ret == -ENOSPC)
2071 failed++;
2072 key.offset -= 1;
2073 }
2074
2075 if (failed && !retried) {
2076 failed = 0;
2077 retried = true;
2078 goto again;
2079 } else if (failed && retried) {
2080 ret = -ENOSPC;
2081 lock_chunks(root);
2082
2083 device->total_bytes = old_size;
2084 if (device->writeable)
2085 device->fs_devices->total_rw_bytes += diff;
2086 unlock_chunks(root);
2087 goto done;
8f18cf13
CM		 2088 }
2089
d6397bae 2090 /* Shrinking succeeded, else we would be at "done". */
a22285a6 2091 trans = btrfs_start_transaction(root, 0);
d6397bae
CB		 2092 lock_chunks(root);
2093
2094 device->disk_total_bytes = new_size;
2095 /* Now btrfs_update_device() will change the on-disk size. */
2096 ret = btrfs_update_device(trans, device);
2097 if (ret) {
2098 unlock_chunks(root);
2099 btrfs_end_transaction(trans, root);
2100 goto done;
2101 }
2102 WARN_ON(diff > old_total);
2103 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2104 unlock_chunks(root);
2105 btrfs_end_transaction(trans, root);
8f18cf13
CM		 2106done:
2107 btrfs_free_path(path);
2108 return ret;
2109}
2110
b2950863 2111static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
0b86a832
CM		 2112 struct btrfs_root *root,
2113 struct btrfs_key *key,
2114 struct btrfs_chunk *chunk, int item_size)
2115{
2116 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2117 struct btrfs_disk_key disk_key;
2118 u32 array_size;
2119 u8 *ptr;
2120
2121 array_size = btrfs_super_sys_array_size(super_copy);
2122 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2123 return -EFBIG;
2124
2125 ptr = super_copy->sys_chunk_array + array_size;
2126 btrfs_cpu_key_to_disk(&disk_key, key);
2127 memcpy(ptr, &disk_key, sizeof(disk_key));
2128 ptr += sizeof(disk_key);
2129 memcpy(ptr, chunk, item_size);
2130 item_size += sizeof(disk_key);
2131 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2132 return 0;
2133}
2134
d397712b 2135static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size,
a1b32a59 2136 int num_stripes, int sub_stripes)
9b3f68b9
CM		 2137{
2138 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
2139 return calc_size;
2140 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2141 return calc_size * (num_stripes / sub_stripes);
2142 else
2143 return calc_size * num_stripes;
2144}
2145
2b82032c
YZ		 2146static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2147 struct btrfs_root *extent_root,
2148 struct map_lookup **map_ret,
2149 u64 *num_bytes, u64 *stripe_size,
2150 u64 start, u64 type)
0b86a832 2151{
593060d7 2152 struct btrfs_fs_info *info = extent_root->fs_info;
0b86a832 2153 struct btrfs_device *device = NULL;
2b82032c 2154 struct btrfs_fs_devices *fs_devices = info->fs_devices;
6324fbf3 2155 struct list_head *cur;
2b82032c 2156 struct map_lookup *map = NULL;
0b86a832 2157 struct extent_map_tree *em_tree;
0b86a832 2158 struct extent_map *em;
2b82032c 2159 struct list_head private_devs;
a40a90a0 2160 int min_stripe_size = 1 * 1024 * 1024;
0b86a832 2161 u64 calc_size = 1024 * 1024 * 1024;
9b3f68b9
CM		 2162 u64 max_chunk_size = calc_size;
2163 u64 min_free;
6324fbf3
CM		 2164 u64 avail;
2165 u64 max_avail = 0;
2b82032c 2166 u64 dev_offset;
6324fbf3 2167 int num_stripes = 1;
a40a90a0 2168 int min_stripes = 1;
321aecc6 2169 int sub_stripes = 0;
6324fbf3 2170 int looped = 0;
0b86a832 2171 int ret;
6324fbf3 2172 int index;
593060d7 2173 int stripe_len = 64 * 1024;
0b86a832 2174
ec44a35c
CM		 2175 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2176 (type & BTRFS_BLOCK_GROUP_DUP)) {
2177 WARN_ON(1);
2178 type &= ~BTRFS_BLOCK_GROUP_DUP;
2179 }
2b82032c 2180 if (list_empty(&fs_devices->alloc_list))
6324fbf3 2181 return -ENOSPC;
593060d7 2182
a40a90a0 2183 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2b82032c 2184 num_stripes = fs_devices->rw_devices;
a40a90a0
CM		 2185 min_stripes = 2;
2186 }
2187 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
611f0e00 2188 num_stripes = 2;
a40a90a0
CM		 2189 min_stripes = 2;
2190 }
8790d502 2191 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
f3eae7e8 2192 if (fs_devices->rw_devices < 2)
9b3f68b9 2193 return -ENOSPC;
f3eae7e8 2194 num_stripes = 2;
a40a90a0 2195 min_stripes = 2;
8790d502 2196 }
321aecc6 2197 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2b82032c 2198 num_stripes = fs_devices->rw_devices;
321aecc6
CM		 2199 if (num_stripes < 4)
2200 return -ENOSPC;
2201 num_stripes &= ~(u32)1;
2202 sub_stripes = 2;
a40a90a0 2203 min_stripes = 4;
321aecc6 2204 }
9b3f68b9
CM		 2205
2206 if (type & BTRFS_BLOCK_GROUP_DATA) {
2207 max_chunk_size = 10 * calc_size;
a40a90a0 2208 min_stripe_size = 64 * 1024 * 1024;
9b3f68b9 2209 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
83d3c969 2210 max_chunk_size = 256 * 1024 * 1024;
a40a90a0
CM		 2211 min_stripe_size = 32 * 1024 * 1024;
2212 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2213 calc_size = 8 * 1024 * 1024;
2214 max_chunk_size = calc_size * 2;
2215 min_stripe_size = 1 * 1024 * 1024;
9b3f68b9
CM		 2216 }
2217
2b82032c
YZ		 2218 /* we don't want a chunk larger than 10% of writeable space */
2219 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2220 max_chunk_size);
9b3f68b9 2221
a40a90a0 2222again:
9779b72f 2223 max_avail = 0;
2b82032c
YZ		 2224 if (!map || map->num_stripes != num_stripes) {
2225 kfree(map);
2226 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2227 if (!map)
2228 return -ENOMEM;
2229 map->num_stripes = num_stripes;
2230 }
2231
9b3f68b9
CM		 2232 if (calc_size * num_stripes > max_chunk_size) {
2233 calc_size = max_chunk_size;
2234 do_div(calc_size, num_stripes);
2235 do_div(calc_size, stripe_len);
2236 calc_size *= stripe_len;
2237 }
0cad8a11 2238
9b3f68b9 2239 /* we don't want tiny stripes */
0cad8a11
JB		 2240 if (!looped)
2241 calc_size = max_t(u64, min_stripe_size, calc_size);
9b3f68b9 2242
9f680ce0
CM		 2243 /*
2244 * we're about to do_div by the stripe_len so lets make sure
2245 * we end up with something bigger than a stripe
2246 */
2247 calc_size = max_t(u64, calc_size, stripe_len * 4);
2248
9b3f68b9
CM		 2249 do_div(calc_size, stripe_len);
2250 calc_size *= stripe_len;
2251
2b82032c 2252 cur = fs_devices->alloc_list.next;
6324fbf3 2253 index = 0;
611f0e00
CM		 2254
2255 if (type & BTRFS_BLOCK_GROUP_DUP)
2256 min_free = calc_size * 2;
9b3f68b9
CM		 2257 else
2258 min_free = calc_size;
611f0e00 2259
0f9dd46c
JB		 2260 /*
2261 * we add 1MB because we never use the first 1MB of the device, unless
2262 * we've looped, then we are likely allocating the maximum amount of
2263 * space left already
2264 */
2265 if (!looped)
2266 min_free += 1024 * 1024;
ad5bd91e 2267
2b82032c 2268 INIT_LIST_HEAD(&private_devs);
d397712b 2269 while (index < num_stripes) {
b3075717 2270 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2b82032c 2271 BUG_ON(!device->writeable);
dfe25020
CM		 2272 if (device->total_bytes > device->bytes_used)
2273 avail = device->total_bytes - device->bytes_used;
2274 else
2275 avail = 0;
6324fbf3 2276 cur = cur->next;
8f18cf13 2277
dfe25020 2278 if (device->in_fs_metadata && avail >= min_free) {
2b82032c 2279 ret = find_free_dev_extent(trans, device,
9779b72f
CM		 2280 min_free, &dev_offset,
2281 &max_avail);
8f18cf13
CM		 2282 if (ret == 0) {
2283 list_move_tail(&device->dev_alloc_list,
2284 &private_devs);
2b82032c
YZ		 2285 map->stripes[index].dev = device;
2286 map->stripes[index].physical = dev_offset;
611f0e00 2287 index++;
2b82032c
YZ		 2288 if (type & BTRFS_BLOCK_GROUP_DUP) {
2289 map->stripes[index].dev = device;
2290 map->stripes[index].physical =
2291 dev_offset + calc_size;
8f18cf13 2292 index++;
2b82032c 2293 }
8f18cf13 2294 }
dfe25020 2295 } else if (device->in_fs_metadata && avail > max_avail)
a40a90a0 2296 max_avail = avail;
2b82032c 2297 if (cur == &fs_devices->alloc_list)
6324fbf3
CM		 2298 break;
2299 }
2b82032c 2300 list_splice(&private_devs, &fs_devices->alloc_list);
6324fbf3 2301 if (index < num_stripes) {
a40a90a0
CM		 2302 if (index >= min_stripes) {
2303 num_stripes = index;
2304 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2305 num_stripes /= sub_stripes;
2306 num_stripes *= sub_stripes;
2307 }
2308 looped = 1;
2309 goto again;
2310 }
6324fbf3
CM		 2311 if (!looped && max_avail > 0) {
2312 looped = 1;
2313 calc_size = max_avail;
2314 goto again;
2315 }
2b82032c 2316 kfree(map);
6324fbf3
CM		 2317 return -ENOSPC;
2318 }
2b82032c
YZ		 2319 map->sector_size = extent_root->sectorsize;
2320 map->stripe_len = stripe_len;
2321 map->io_align = stripe_len;
2322 map->io_width = stripe_len;
2323 map->type = type;
2324 map->num_stripes = num_stripes;
2325 map->sub_stripes = sub_stripes;
0b86a832 2326
2b82032c
YZ		 2327 *map_ret = map;
2328 *stripe_size = calc_size;
2329 *num_bytes = chunk_bytes_by_type(type, calc_size,
2330 num_stripes, sub_stripes);
0b86a832 2331
2b82032c
YZ		 2332 em = alloc_extent_map(GFP_NOFS);
2333 if (!em) {
2334 kfree(map);
593060d7
CM		 2335 return -ENOMEM;
2336 }
2b82032c
YZ		 2337 em->bdev = (struct block_device *)map;
2338 em->start = start;
2339 em->len = *num_bytes;
2340 em->block_start = 0;
2341 em->block_len = em->len;
593060d7 2342
2b82032c 2343 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
890871be 2344 write_lock(&em_tree->lock);
2b82032c 2345 ret = add_extent_mapping(em_tree, em);
890871be 2346 write_unlock(&em_tree->lock);
2b82032c
YZ		 2347 BUG_ON(ret);
2348 free_extent_map(em);
0b86a832 2349
2b82032c
YZ		 2350 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2351 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2352 start, *num_bytes);
2353 BUG_ON(ret);
611f0e00 2354
2b82032c
YZ		 2355 index = 0;
2356 while (index < map->num_stripes) {
2357 device = map->stripes[index].dev;
2358 dev_offset = map->stripes[index].physical;
0b86a832
CM		 2359
2360 ret = btrfs_alloc_dev_extent(trans, device,
2b82032c
YZ		 2361 info->chunk_root->root_key.objectid,
2362 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2363 start, dev_offset, calc_size);
0b86a832 2364 BUG_ON(ret);
2b82032c
YZ		 2365 index++;
2366 }
2367
2368 return 0;
2369}
2370
2371static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2372 struct btrfs_root *extent_root,
2373 struct map_lookup *map, u64 chunk_offset,
2374 u64 chunk_size, u64 stripe_size)
2375{
2376 u64 dev_offset;
2377 struct btrfs_key key;
2378 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2379 struct btrfs_device *device;
2380 struct btrfs_chunk *chunk;
2381 struct btrfs_stripe *stripe;
2382 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2383 int index = 0;
2384 int ret;
2385
2386 chunk = kzalloc(item_size, GFP_NOFS);
2387 if (!chunk)
2388 return -ENOMEM;
2389
2390 index = 0;
2391 while (index < map->num_stripes) {
2392 device = map->stripes[index].dev;
2393 device->bytes_used += stripe_size;
0b86a832
CM		 2394 ret = btrfs_update_device(trans, device);
2395 BUG_ON(ret);
2b82032c
YZ		 2396 index++;
2397 }
2398
2399 index = 0;
2400 stripe = &chunk->stripe;
2401 while (index < map->num_stripes) {
2402 device = map->stripes[index].dev;
2403 dev_offset = map->stripes[index].physical;
0b86a832 2404
e17cade2
CM		 2405 btrfs_set_stack_stripe_devid(stripe, device->devid);
2406 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2407 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2b82032c 2408 stripe++;
0b86a832
CM		 2409 index++;
2410 }
2411
2b82032c 2412 btrfs_set_stack_chunk_length(chunk, chunk_size);
0b86a832 2413 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2b82032c
YZ		 2414 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2415 btrfs_set_stack_chunk_type(chunk, map->type);
2416 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2417 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2418 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
0b86a832 2419 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2b82032c 2420 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
0b86a832 2421
2b82032c
YZ		 2422 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2423 key.type = BTRFS_CHUNK_ITEM_KEY;
2424 key.offset = chunk_offset;
0b86a832 2425
2b82032c
YZ		 2426 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2427 BUG_ON(ret);
0b86a832 2428
2b82032c
YZ		 2429 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2430 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2431 item_size);
8f18cf13
CM		 2432 BUG_ON(ret);
2433 }
0b86a832 2434 kfree(chunk);
2b82032c
YZ		 2435 return 0;
2436}
0b86a832 2437
2b82032c
YZ		 2438/*
2439 * Chunk allocation falls into two parts. The first part does works
2440 * that make the new allocated chunk useable, but not do any operation
2441 * that modifies the chunk tree. The second part does the works that
2442 * require modifying the chunk tree. This division is important for the
2443 * bootstrap process of adding storage to a seed btrfs.
2444 */
2445int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2446 struct btrfs_root *extent_root, u64 type)
2447{
2448 u64 chunk_offset;
2449 u64 chunk_size;
2450 u64 stripe_size;
2451 struct map_lookup *map;
2452 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2453 int ret;
2454
2455 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2456 &chunk_offset);
2457 if (ret)
2458 return ret;
2459
2460 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2461 &stripe_size, chunk_offset, type);
2462 if (ret)
2463 return ret;
2464
2465 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2466 chunk_size, stripe_size);
2467 BUG_ON(ret);
2468 return 0;
2469}
2470
d397712b 2471static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2b82032c
YZ		 2472 struct btrfs_root *root,
2473 struct btrfs_device *device)
2474{
2475 u64 chunk_offset;
2476 u64 sys_chunk_offset;
2477 u64 chunk_size;
2478 u64 sys_chunk_size;
2479 u64 stripe_size;
2480 u64 sys_stripe_size;
2481 u64 alloc_profile;
2482 struct map_lookup *map;
2483 struct map_lookup *sys_map;
2484 struct btrfs_fs_info *fs_info = root->fs_info;
2485 struct btrfs_root *extent_root = fs_info->extent_root;
2486 int ret;
2487
2488 ret = find_next_chunk(fs_info->chunk_root,
2489 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2490 BUG_ON(ret);
2491
2492 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2493 (fs_info->metadata_alloc_profile &
2494 fs_info->avail_metadata_alloc_bits);
2495 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2496
2497 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2498 &stripe_size, chunk_offset, alloc_profile);
2499 BUG_ON(ret);
2500
2501 sys_chunk_offset = chunk_offset + chunk_size;
2502
2503 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2504 (fs_info->system_alloc_profile &
2505 fs_info->avail_system_alloc_bits);
2506 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2507
2508 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2509 &sys_chunk_size, &sys_stripe_size,
2510 sys_chunk_offset, alloc_profile);
2511 BUG_ON(ret);
2512
2513 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2514 BUG_ON(ret);
2515
2516 /*
2517 * Modifying chunk tree needs allocating new blocks from both
2518 * system block group and metadata block group. So we only can
2519 * do operations require modifying the chunk tree after both
2520 * block groups were created.
2521 */
2522 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2523 chunk_size, stripe_size);
2524 BUG_ON(ret);
2525
2526 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2527 sys_chunk_offset, sys_chunk_size,
2528 sys_stripe_size);
b248a415 2529 BUG_ON(ret);
2b82032c
YZ		 2530 return 0;
2531}
2532
2533int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2534{
2535 struct extent_map *em;
2536 struct map_lookup *map;
2537 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2538 int readonly = 0;
2539 int i;
2540
890871be 2541 read_lock(&map_tree->map_tree.lock);
2b82032c 2542 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
890871be 2543 read_unlock(&map_tree->map_tree.lock);
2b82032c
YZ		 2544 if (!em)
2545 return 1;
2546
f48b9075
JB		 2547 if (btrfs_test_opt(root, DEGRADED)) {
2548 free_extent_map(em);
2549 return 0;
2550 }
2551
2b82032c
YZ		 2552 map = (struct map_lookup *)em->bdev;
2553 for (i = 0; i < map->num_stripes; i++) {
2554 if (!map->stripes[i].dev->writeable) {
2555 readonly = 1;
2556 break;
2557 }
2558 }
0b86a832 2559 free_extent_map(em);
2b82032c 2560 return readonly;
0b86a832
CM		 2561}
2562
2563void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2564{
2565 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
2566}
2567
2568void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2569{
2570 struct extent_map *em;
2571
d397712b 2572 while (1) {
890871be 2573 write_lock(&tree->map_tree.lock);
0b86a832
CM		 2574 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2575 if (em)
2576 remove_extent_mapping(&tree->map_tree, em);
890871be 2577 write_unlock(&tree->map_tree.lock);
0b86a832
CM		 2578 if (!em)
2579 break;
2580 kfree(em->bdev);
2581 /* once for us */
2582 free_extent_map(em);
2583 /* once for the tree */
2584 free_extent_map(em);
2585 }
2586}
2587
f188591e
CM		 2588int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2589{
2590 struct extent_map *em;
2591 struct map_lookup *map;
2592 struct extent_map_tree *em_tree = &map_tree->map_tree;
2593 int ret;
2594
890871be 2595 read_lock(&em_tree->lock);
f188591e 2596 em = lookup_extent_mapping(em_tree, logical, len);
890871be 2597 read_unlock(&em_tree->lock);
f188591e
CM		 2598 BUG_ON(!em);
2599
2600 BUG_ON(em->start > logical || em->start + em->len < logical);
2601 map = (struct map_lookup *)em->bdev;
2602 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2603 ret = map->num_stripes;
321aecc6
CM		 2604 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2605 ret = map->sub_stripes;
f188591e
CM		 2606 else
2607 ret = 1;
2608 free_extent_map(em);
f188591e
CM		 2609 return ret;
2610}
2611
dfe25020
CM		 2612static int find_live_mirror(struct map_lookup *map, int first, int num,
2613 int optimal)
2614{
2615 int i;
2616 if (map->stripes[optimal].dev->bdev)
2617 return optimal;
2618 for (i = first; i < first + num; i++) {
2619 if (map->stripes[i].dev->bdev)
2620 return i;
2621 }
2622 /* we couldn't find one that doesn't fail. Just return something
2623 * and the io error handling code will clean up eventually
2624 */
2625 return optimal;
2626}
2627
f2d8d74d
CM		 2628static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2629 u64 logical, u64 *length,
2630 struct btrfs_multi_bio **multi_ret,
2631 int mirror_num, struct page *unplug_page)
0b86a832
CM		 2632{
2633 struct extent_map *em;
2634 struct map_lookup *map;
2635 struct extent_map_tree *em_tree = &map_tree->map_tree;
2636 u64 offset;
593060d7
CM		 2637 u64 stripe_offset;
2638 u64 stripe_nr;
cea9e445 2639 int stripes_allocated = 8;
321aecc6 2640 int stripes_required = 1;
593060d7 2641 int stripe_index;
cea9e445 2642 int i;
f2d8d74d 2643 int num_stripes;
a236aed1 2644 int max_errors = 0;
cea9e445 2645 struct btrfs_multi_bio *multi = NULL;
0b86a832 2646
7b6d91da 2647 if (multi_ret && !(rw & REQ_WRITE))
cea9e445 2648 stripes_allocated = 1;
cea9e445
CM		 2649again:
2650 if (multi_ret) {
2651 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2652 GFP_NOFS);
2653 if (!multi)
2654 return -ENOMEM;
a236aed1
CM		 2655
2656 atomic_set(&multi->error, 0);
cea9e445 2657 }
0b86a832 2658
890871be 2659 read_lock(&em_tree->lock);
0b86a832 2660 em = lookup_extent_mapping(em_tree, logical, *length);
890871be 2661 read_unlock(&em_tree->lock);
f2d8d74d 2662
2423fdfb
JS		 2663 if (!em && unplug_page) {
2664 kfree(multi);
f2d8d74d 2665 return 0;
2423fdfb 2666 }
f2d8d74d 2667
3b951516 2668 if (!em) {
d397712b
CM		 2669 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2670 (unsigned long long)logical,
2671 (unsigned long long)*length);
f2d8d74d 2672 BUG();
3b951516 2673 }
0b86a832
CM		 2674
2675 BUG_ON(em->start > logical || em->start + em->len < logical);
2676 map = (struct map_lookup *)em->bdev;
2677 offset = logical - em->start;
593060d7 2678
f188591e
CM		 2679 if (mirror_num > map->num_stripes)
2680 mirror_num = 0;
2681
cea9e445 2682 /* if our multi bio struct is too small, back off and try again */
7b6d91da 2683 if (rw & REQ_WRITE) {
321aecc6
CM		 2684 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2685 BTRFS_BLOCK_GROUP_DUP)) {
2686 stripes_required = map->num_stripes;
a236aed1 2687 max_errors = 1;
321aecc6
CM		 2688 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2689 stripes_required = map->sub_stripes;
a236aed1 2690 max_errors = 1;
321aecc6
CM		 2691 }
2692 }
7b6d91da 2693 if (multi_ret && (rw & REQ_WRITE) &&
321aecc6 2694 stripes_allocated < stripes_required) {
cea9e445 2695 stripes_allocated = map->num_stripes;
cea9e445
CM		 2696 free_extent_map(em);
2697 kfree(multi);
2698 goto again;
2699 }
593060d7
CM		 2700 stripe_nr = offset;
2701 /*
2702 * stripe_nr counts the total number of stripes we have to stride
2703 * to get to this block
2704 */
2705 do_div(stripe_nr, map->stripe_len);
2706
2707 stripe_offset = stripe_nr * map->stripe_len;
2708 BUG_ON(offset < stripe_offset);
2709
2710 /* stripe_offset is the offset of this block in its stripe*/
2711 stripe_offset = offset - stripe_offset;
2712
cea9e445 2713 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
321aecc6 2714 BTRFS_BLOCK_GROUP_RAID10 |
cea9e445
CM		 2715 BTRFS_BLOCK_GROUP_DUP)) {
2716 /* we limit the length of each bio to what fits in a stripe */
2717 *length = min_t(u64, em->len - offset,
2718 map->stripe_len - stripe_offset);
2719 } else {
2720 *length = em->len - offset;
2721 }
f2d8d74d
CM		 2722
2723 if (!multi_ret && !unplug_page)
cea9e445
CM		 2724 goto out;
2725
f2d8d74d 2726 num_stripes = 1;
cea9e445 2727 stripe_index = 0;
8790d502 2728 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
7b6d91da 2729 if (unplug_page || (rw & REQ_WRITE))
f2d8d74d 2730 num_stripes = map->num_stripes;
2fff734f 2731 else if (mirror_num)
f188591e 2732 stripe_index = mirror_num - 1;
dfe25020
CM		 2733 else {
2734 stripe_index = find_live_mirror(map, 0,
2735 map->num_stripes,
2736 current->pid % map->num_stripes);
2737 }
2fff734f 2738
611f0e00 2739 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
7b6d91da 2740 if (rw & REQ_WRITE)
f2d8d74d 2741 num_stripes = map->num_stripes;
f188591e
CM		 2742 else if (mirror_num)
2743 stripe_index = mirror_num - 1;
2fff734f 2744
321aecc6
CM		 2745 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2746 int factor = map->num_stripes / map->sub_stripes;
321aecc6
CM		 2747
2748 stripe_index = do_div(stripe_nr, factor);
2749 stripe_index *= map->sub_stripes;
2750
7b6d91da 2751 if (unplug_page || (rw & REQ_WRITE))
f2d8d74d 2752 num_stripes = map->sub_stripes;
321aecc6
CM		 2753 else if (mirror_num)
2754 stripe_index += mirror_num - 1;
dfe25020
CM		 2755 else {
2756 stripe_index = find_live_mirror(map, stripe_index,
2757 map->sub_stripes, stripe_index +
2758 current->pid % map->sub_stripes);
2759 }
8790d502
CM		 2760 } else {
2761 /*
2762 * after this do_div call, stripe_nr is the number of stripes
2763 * on this device we have to walk to find the data, and
2764 * stripe_index is the number of our device in the stripe array
2765 */
2766 stripe_index = do_div(stripe_nr, map->num_stripes);
2767 }
593060d7 2768 BUG_ON(stripe_index >= map->num_stripes);
cea9e445 2769
f2d8d74d
CM		 2770 for (i = 0; i < num_stripes; i++) {
2771 if (unplug_page) {
2772 struct btrfs_device *device;
2773 struct backing_dev_info *bdi;
2774
2775 device = map->stripes[stripe_index].dev;
dfe25020
CM		 2776 if (device->bdev) {
2777 bdi = blk_get_backing_dev_info(device->bdev);
d397712b 2778 if (bdi->unplug_io_fn)
dfe25020 2779 bdi->unplug_io_fn(bdi, unplug_page);
f2d8d74d
CM		 2780 }
2781 } else {
2782 multi->stripes[i].physical =
2783 map->stripes[stripe_index].physical +
2784 stripe_offset + stripe_nr * map->stripe_len;
2785 multi->stripes[i].dev = map->stripes[stripe_index].dev;
2786 }
cea9e445 2787 stripe_index++;
593060d7 2788 }
f2d8d74d
CM		 2789 if (multi_ret) {
2790 *multi_ret = multi;
2791 multi->num_stripes = num_stripes;
a236aed1 2792 multi->max_errors = max_errors;
f2d8d74d 2793 }
cea9e445 2794out:
0b86a832 2795 free_extent_map(em);
0b86a832
CM		 2796 return 0;
2797}
2798
f2d8d74d
CM		 2799int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2800 u64 logical, u64 *length,
2801 struct btrfs_multi_bio **multi_ret, int mirror_num)
2802{
2803 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
2804 mirror_num, NULL);
2805}
2806
a512bbf8
YZ		 2807int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
2808 u64 chunk_start, u64 physical, u64 devid,
2809 u64 **logical, int *naddrs, int *stripe_len)
2810{
2811 struct extent_map_tree *em_tree = &map_tree->map_tree;
2812 struct extent_map *em;
2813 struct map_lookup *map;
2814 u64 *buf;
2815 u64 bytenr;
2816 u64 length;
2817 u64 stripe_nr;
2818 int i, j, nr = 0;
2819
890871be 2820 read_lock(&em_tree->lock);
a512bbf8 2821 em = lookup_extent_mapping(em_tree, chunk_start, 1);
890871be 2822 read_unlock(&em_tree->lock);
a512bbf8
YZ		 2823
2824 BUG_ON(!em || em->start != chunk_start);
2825 map = (struct map_lookup *)em->bdev;
2826
2827 length = em->len;
2828 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2829 do_div(length, map->num_stripes / map->sub_stripes);
2830 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
2831 do_div(length, map->num_stripes);
2832
2833 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
2834 BUG_ON(!buf);
2835
2836 for (i = 0; i < map->num_stripes; i++) {
2837 if (devid && map->stripes[i].dev->devid != devid)
2838 continue;
2839 if (map->stripes[i].physical > physical ||
2840 map->stripes[i].physical + length <= physical)
2841 continue;
2842
2843 stripe_nr = physical - map->stripes[i].physical;
2844 do_div(stripe_nr, map->stripe_len);
2845
2846 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2847 stripe_nr = stripe_nr * map->num_stripes + i;
2848 do_div(stripe_nr, map->sub_stripes);
2849 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2850 stripe_nr = stripe_nr * map->num_stripes + i;
2851 }
2852 bytenr = chunk_start + stripe_nr * map->stripe_len;
934d375b 2853 WARN_ON(nr >= map->num_stripes);
a512bbf8
YZ		 2854 for (j = 0; j < nr; j++) {
2855 if (buf[j] == bytenr)
2856 break;
2857 }
934d375b
CM		 2858 if (j == nr) {
2859 WARN_ON(nr >= map->num_stripes);
a512bbf8 2860 buf[nr++] = bytenr;
934d375b 2861 }
a512bbf8
YZ		 2862 }
2863
a512bbf8
YZ		 2864 *logical = buf;
2865 *naddrs = nr;
2866 *stripe_len = map->stripe_len;
2867
2868 free_extent_map(em);
2869 return 0;
2870}
2871
f2d8d74d
CM		 2872int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
2873 u64 logical, struct page *page)
2874{
2875 u64 length = PAGE_CACHE_SIZE;
2876 return __btrfs_map_block(map_tree, READ, logical, &length,
2877 NULL, 0, page);
2878}
2879
8790d502 2880static void end_bio_multi_stripe(struct bio *bio, int err)
8790d502 2881{
cea9e445 2882 struct btrfs_multi_bio *multi = bio->bi_private;
7d2b4daa 2883 int is_orig_bio = 0;
8790d502 2884
8790d502 2885 if (err)
a236aed1 2886 atomic_inc(&multi->error);
8790d502 2887
7d2b4daa
CM		 2888 if (bio == multi->orig_bio)
2889 is_orig_bio = 1;
2890
cea9e445 2891 if (atomic_dec_and_test(&multi->stripes_pending)) {
7d2b4daa
CM		 2892 if (!is_orig_bio) {
2893 bio_put(bio);
2894 bio = multi->orig_bio;
2895 }
8790d502
CM		 2896 bio->bi_private = multi->private;
2897 bio->bi_end_io = multi->end_io;
a236aed1
CM		 2898 /* only send an error to the higher layers if it is
2899 * beyond the tolerance of the multi-bio
2900 */
1259ab75 2901 if (atomic_read(&multi->error) > multi->max_errors) {
a236aed1 2902 err = -EIO;
1259ab75
CM		 2903 } else if (err) {
2904 /*
2905 * this bio is actually up to date, we didn't
2906 * go over the max number of errors
2907 */
2908 set_bit(BIO_UPTODATE, &bio->bi_flags);
a236aed1 2909 err = 0;
1259ab75 2910 }
8790d502
CM		 2911 kfree(multi);
2912
2913 bio_endio(bio, err);
7d2b4daa 2914 } else if (!is_orig_bio) {
8790d502
CM		 2915 bio_put(bio);
2916 }
8790d502
CM		 2917}
2918
8b712842
CM		 2919struct async_sched {
2920 struct bio *bio;
2921 int rw;
2922 struct btrfs_fs_info *info;
2923 struct btrfs_work work;
2924};
2925
2926/*
2927 * see run_scheduled_bios for a description of why bios are collected for
2928 * async submit.
2929 *
2930 * This will add one bio to the pending list for a device and make sure
2931 * the work struct is scheduled.
2932 */
d397712b 2933static noinline int schedule_bio(struct btrfs_root *root,
a1b32a59
CM		 2934 struct btrfs_device *device,
2935 int rw, struct bio *bio)
8b712842
CM		 2936{
2937 int should_queue = 1;
ffbd517d 2938 struct btrfs_pending_bios *pending_bios;
8b712842
CM		 2939
2940 /* don't bother with additional async steps for reads, right now */
7b6d91da 2941 if (!(rw & REQ_WRITE)) {
492bb6de 2942 bio_get(bio);
8b712842 2943 submit_bio(rw, bio);
492bb6de 2944 bio_put(bio);
8b712842
CM		 2945 return 0;
2946 }
2947
2948 /*
0986fe9e 2949 * nr_async_bios allows us to reliably return congestion to the
8b712842
CM		 2950 * higher layers. Otherwise, the async bio makes it appear we have
2951 * made progress against dirty pages when we've really just put it
2952 * on a queue for later
2953 */
0986fe9e 2954 atomic_inc(&root->fs_info->nr_async_bios);
492bb6de 2955 WARN_ON(bio->bi_next);
8b712842
CM		 2956 bio->bi_next = NULL;
2957 bio->bi_rw |= rw;
2958
2959 spin_lock(&device->io_lock);
7b6d91da 2960 if (bio->bi_rw & REQ_SYNC)
ffbd517d
CM		 2961 pending_bios = &device->pending_sync_bios;
2962 else
2963 pending_bios = &device->pending_bios;
8b712842 2964
ffbd517d
CM		 2965 if (pending_bios->tail)
2966 pending_bios->tail->bi_next = bio;
8b712842 2967
ffbd517d
CM		 2968 pending_bios->tail = bio;
2969 if (!pending_bios->head)
2970 pending_bios->head = bio;
8b712842
CM		 2971 if (device->running_pending)
2972 should_queue = 0;
2973
2974 spin_unlock(&device->io_lock);
2975
2976 if (should_queue)
1cc127b5
CM		 2977 btrfs_queue_worker(&root->fs_info->submit_workers,
2978 &device->work);
8b712842
CM		 2979 return 0;
2980}
2981
f188591e 2982int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
8b712842 2983 int mirror_num, int async_submit)
0b86a832
CM		 2984{
2985 struct btrfs_mapping_tree *map_tree;
2986 struct btrfs_device *dev;
8790d502 2987 struct bio *first_bio = bio;
a62b9401 2988 u64 logical = (u64)bio->bi_sector << 9;
0b86a832
CM		 2989 u64 length = 0;
2990 u64 map_length;
cea9e445 2991 struct btrfs_multi_bio *multi = NULL;
0b86a832 2992 int ret;
8790d502
CM		 2993 int dev_nr = 0;
2994 int total_devs = 1;
0b86a832 2995
f2d8d74d 2996 length = bio->bi_size;
0b86a832
CM		 2997 map_tree = &root->fs_info->mapping_tree;
2998 map_length = length;
cea9e445 2999
f188591e
CM		 3000 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
3001 mirror_num);
cea9e445
CM		 3002 BUG_ON(ret);
3003
3004 total_devs = multi->num_stripes;
3005 if (map_length < length) {
d397712b
CM		 3006 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3007 "len %llu\n", (unsigned long long)logical,
3008 (unsigned long long)length,
3009 (unsigned long long)map_length);
cea9e445
CM		 3010 BUG();
3011 }
3012 multi->end_io = first_bio->bi_end_io;
3013 multi->private = first_bio->bi_private;
7d2b4daa 3014 multi->orig_bio = first_bio;
cea9e445
CM		 3015 atomic_set(&multi->stripes_pending, multi->num_stripes);
3016
d397712b 3017 while (dev_nr < total_devs) {
8790d502 3018 if (total_devs > 1) {
8790d502
CM		 3019 if (dev_nr < total_devs - 1) {
3020 bio = bio_clone(first_bio, GFP_NOFS);
3021 BUG_ON(!bio);
3022 } else {
3023 bio = first_bio;
3024 }
3025 bio->bi_private = multi;
3026 bio->bi_end_io = end_bio_multi_stripe;
3027 }
cea9e445
CM		 3028 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
3029 dev = multi->stripes[dev_nr].dev;
18e503d6 3030 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
dfe25020 3031 bio->bi_bdev = dev->bdev;
8b712842
CM		 3032 if (async_submit)
3033 schedule_bio(root, dev, rw, bio);
3034 else
3035 submit_bio(rw, bio);
dfe25020
CM		 3036 } else {
3037 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3038 bio->bi_sector = logical >> 9;
dfe25020 3039 bio_endio(bio, -EIO);
dfe25020 3040 }
8790d502
CM		 3041 dev_nr++;
3042 }
cea9e445
CM		 3043 if (total_devs == 1)
3044 kfree(multi);
0b86a832
CM		 3045 return 0;
3046}
3047
a443755f 3048struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
2b82032c 3049 u8 *uuid, u8 *fsid)
0b86a832 3050{
2b82032c
YZ		 3051 struct btrfs_device *device;
3052 struct btrfs_fs_devices *cur_devices;
3053
3054 cur_devices = root->fs_info->fs_devices;
3055 while (cur_devices) {
3056 if (!fsid ||
3057 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3058 device = __find_device(&cur_devices->devices,
3059 devid, uuid);
3060 if (device)
3061 return device;
3062 }
3063 cur_devices = cur_devices->seed;
3064 }
3065 return NULL;
0b86a832
CM		 3066}
3067
dfe25020
CM		 3068static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3069 u64 devid, u8 *dev_uuid)
3070{
3071 struct btrfs_device *device;
3072 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3073
3074 device = kzalloc(sizeof(*device), GFP_NOFS);
7cbd8a83 3075 if (!device)
3076 return NULL;
dfe25020
CM		 3077 list_add(&device->dev_list,
3078 &fs_devices->devices);
dfe25020
CM		 3079 device->dev_root = root->fs_info->dev_root;
3080 device->devid = devid;
8b712842 3081 device->work.func = pending_bios_fn;
e4404d6e 3082 device->fs_devices = fs_devices;
dfe25020
CM		 3083 fs_devices->num_devices++;
3084 spin_lock_init(&device->io_lock);
d20f7043 3085 INIT_LIST_HEAD(&device->dev_alloc_list);
dfe25020
CM		 3086 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3087 return device;
3088}
3089
0b86a832
CM		 3090static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3091 struct extent_buffer *leaf,
3092 struct btrfs_chunk *chunk)
3093{
3094 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3095 struct map_lookup *map;
3096 struct extent_map *em;
3097 u64 logical;
3098 u64 length;
3099 u64 devid;
a443755f 3100 u8 uuid[BTRFS_UUID_SIZE];
593060d7 3101 int num_stripes;
0b86a832 3102 int ret;
593060d7 3103 int i;
0b86a832 3104
e17cade2
CM		 3105 logical = key->offset;
3106 length = btrfs_chunk_length(leaf, chunk);
a061fc8d 3107
890871be 3108 read_lock(&map_tree->map_tree.lock);
0b86a832 3109 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
890871be 3110 read_unlock(&map_tree->map_tree.lock);
0b86a832
CM		 3111
3112 /* already mapped? */
3113 if (em && em->start <= logical && em->start + em->len > logical) {
3114 free_extent_map(em);
0b86a832
CM		 3115 return 0;
3116 } else if (em) {
3117 free_extent_map(em);
3118 }
0b86a832 3119
0b86a832
CM		 3120 em = alloc_extent_map(GFP_NOFS);
3121 if (!em)
3122 return -ENOMEM;
593060d7
CM		 3123 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3124 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
0b86a832
CM		 3125 if (!map) {
3126 free_extent_map(em);
3127 return -ENOMEM;
3128 }
3129
3130 em->bdev = (struct block_device *)map;
3131 em->start = logical;
3132 em->len = length;
3133 em->block_start = 0;
c8b97818 3134 em->block_len = em->len;
0b86a832 3135
593060d7
CM		 3136 map->num_stripes = num_stripes;
3137 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3138 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3139 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3140 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3141 map->type = btrfs_chunk_type(leaf, chunk);
321aecc6 3142 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
593060d7
CM		 3143 for (i = 0; i < num_stripes; i++) {
3144 map->stripes[i].physical =
3145 btrfs_stripe_offset_nr(leaf, chunk, i);
3146 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
a443755f
CM		 3147 read_extent_buffer(leaf, uuid, (unsigned long)
3148 btrfs_stripe_dev_uuid_nr(chunk, i),
3149 BTRFS_UUID_SIZE);
2b82032c
YZ		 3150 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3151 NULL);
dfe25020 3152 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
593060d7
CM		 3153 kfree(map);
3154 free_extent_map(em);
3155 return -EIO;
3156 }
dfe25020
CM		 3157 if (!map->stripes[i].dev) {
3158 map->stripes[i].dev =
3159 add_missing_dev(root, devid, uuid);
3160 if (!map->stripes[i].dev) {
3161 kfree(map);
3162 free_extent_map(em);
3163 return -EIO;
3164 }
3165 }
3166 map->stripes[i].dev->in_fs_metadata = 1;
0b86a832
CM		 3167 }
3168
890871be 3169 write_lock(&map_tree->map_tree.lock);
0b86a832 3170 ret = add_extent_mapping(&map_tree->map_tree, em);
890871be 3171 write_unlock(&map_tree->map_tree.lock);
b248a415 3172 BUG_ON(ret);
0b86a832
CM		 3173 free_extent_map(em);
3174
3175 return 0;
3176}
3177
3178static int fill_device_from_item(struct extent_buffer *leaf,
3179 struct btrfs_dev_item *dev_item,
3180 struct btrfs_device *device)
3181{
3182 unsigned long ptr;
0b86a832
CM		 3183
3184 device->devid = btrfs_device_id(leaf, dev_item);
d6397bae
CB		 3185 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3186 device->total_bytes = device->disk_total_bytes;
0b86a832
CM		 3187 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3188 device->type = btrfs_device_type(leaf, dev_item);
3189 device->io_align = btrfs_device_io_align(leaf, dev_item);
3190 device->io_width = btrfs_device_io_width(leaf, dev_item);
3191 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
0b86a832
CM		 3192
3193 ptr = (unsigned long)btrfs_device_uuid(dev_item);
e17cade2 3194 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
0b86a832 3195
0b86a832
CM		 3196 return 0;
3197}
3198
2b82032c
YZ		 3199static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3200{
3201 struct btrfs_fs_devices *fs_devices;
3202 int ret;
3203
3204 mutex_lock(&uuid_mutex);
3205
3206 fs_devices = root->fs_info->fs_devices->seed;
3207 while (fs_devices) {
3208 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3209 ret = 0;
3210 goto out;
3211 }
3212 fs_devices = fs_devices->seed;
3213 }
3214
3215 fs_devices = find_fsid(fsid);
3216 if (!fs_devices) {
3217 ret = -ENOENT;
3218 goto out;
3219 }
e4404d6e
YZ		 3220
3221 fs_devices = clone_fs_devices(fs_devices);
3222 if (IS_ERR(fs_devices)) {
3223 ret = PTR_ERR(fs_devices);
2b82032c
YZ		 3224 goto out;
3225 }
3226
97288f2c 3227 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
15916de8 3228 root->fs_info->bdev_holder);
2b82032c
YZ		 3229 if (ret)
3230 goto out;
3231
3232 if (!fs_devices->seeding) {
3233 __btrfs_close_devices(fs_devices);
e4404d6e 3234 free_fs_devices(fs_devices);
2b82032c
YZ		 3235 ret = -EINVAL;
3236 goto out;
3237 }
3238
3239 fs_devices->seed = root->fs_info->fs_devices->seed;
3240 root->fs_info->fs_devices->seed = fs_devices;
2b82032c
YZ		 3241out:
3242 mutex_unlock(&uuid_mutex);
3243 return ret;
3244}
3245
0d81ba5d 3246static int read_one_dev(struct btrfs_root *root,
0b86a832
CM		 3247 struct extent_buffer *leaf,
3248 struct btrfs_dev_item *dev_item)
3249{
3250 struct btrfs_device *device;
3251 u64 devid;
3252 int ret;
2b82032c 3253 u8 fs_uuid[BTRFS_UUID_SIZE];
a443755f
CM		 3254 u8 dev_uuid[BTRFS_UUID_SIZE];
3255
0b86a832 3256 devid = btrfs_device_id(leaf, dev_item);
a443755f
CM		 3257 read_extent_buffer(leaf, dev_uuid,
3258 (unsigned long)btrfs_device_uuid(dev_item),
3259 BTRFS_UUID_SIZE);
2b82032c
YZ		 3260 read_extent_buffer(leaf, fs_uuid,
3261 (unsigned long)btrfs_device_fsid(dev_item),
3262 BTRFS_UUID_SIZE);
3263
3264 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3265 ret = open_seed_devices(root, fs_uuid);
e4404d6e 3266 if (ret && !btrfs_test_opt(root, DEGRADED))
2b82032c 3267 return ret;
2b82032c
YZ		 3268 }
3269
3270 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3271 if (!device || !device->bdev) {
e4404d6e 3272 if (!btrfs_test_opt(root, DEGRADED))
2b82032c
YZ		 3273 return -EIO;
3274
3275 if (!device) {
d397712b
CM		 3276 printk(KERN_WARNING "warning devid %llu missing\n",
3277 (unsigned long long)devid);
2b82032c
YZ		 3278 device = add_missing_dev(root, devid, dev_uuid);
3279 if (!device)
3280 return -ENOMEM;
3281 }
3282 }
3283
3284 if (device->fs_devices != root->fs_info->fs_devices) {
3285 BUG_ON(device->writeable);
3286 if (device->generation !=
3287 btrfs_device_generation(leaf, dev_item))
3288 return -EINVAL;
6324fbf3 3289 }
0b86a832
CM		 3290
3291 fill_device_from_item(leaf, dev_item, device);
3292 device->dev_root = root->fs_info->dev_root;
dfe25020 3293 device->in_fs_metadata = 1;
2b82032c
YZ		 3294 if (device->writeable)
3295 device->fs_devices->total_rw_bytes += device->total_bytes;
0b86a832 3296 ret = 0;
0b86a832
CM		 3297 return ret;
3298}
3299
0d81ba5d
CM		 3300int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
3301{
3302 struct btrfs_dev_item *dev_item;
3303
3304 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
3305 dev_item);
3306 return read_one_dev(root, buf, dev_item);
3307}
3308
e4404d6e 3309int btrfs_read_sys_array(struct btrfs_root *root)
0b86a832
CM		 3310{
3311 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
a061fc8d 3312 struct extent_buffer *sb;
0b86a832 3313 struct btrfs_disk_key *disk_key;
0b86a832 3314 struct btrfs_chunk *chunk;
84eed90f
CM		 3315 u8 *ptr;
3316 unsigned long sb_ptr;
3317 int ret = 0;
0b86a832
CM		 3318 u32 num_stripes;
3319 u32 array_size;
3320 u32 len = 0;
0b86a832 3321 u32 cur;
84eed90f 3322 struct btrfs_key key;
0b86a832 3323
e4404d6e 3324 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
a061fc8d
CM		 3325 BTRFS_SUPER_INFO_SIZE);
3326 if (!sb)
3327 return -ENOMEM;
3328 btrfs_set_buffer_uptodate(sb);
4008c04a
CM		 3329 btrfs_set_buffer_lockdep_class(sb, 0);
3330
a061fc8d 3331 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
0b86a832
CM		 3332 array_size = btrfs_super_sys_array_size(super_copy);
3333
0b86a832
CM		 3334 ptr = super_copy->sys_chunk_array;
3335 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3336 cur = 0;
3337
3338 while (cur < array_size) {
3339 disk_key = (struct btrfs_disk_key *)ptr;
3340 btrfs_disk_key_to_cpu(&key, disk_key);
3341
a061fc8d 3342 len = sizeof(*disk_key); ptr += len;
0b86a832
CM		 3343 sb_ptr += len;
3344 cur += len;
3345
0d81ba5d 3346 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
0b86a832 3347 chunk = (struct btrfs_chunk *)sb_ptr;
0d81ba5d 3348 ret = read_one_chunk(root, &key, sb, chunk);
84eed90f
CM		 3349 if (ret)
3350 break;
0b86a832
CM		 3351 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3352 len = btrfs_chunk_item_size(num_stripes);
3353 } else {
84eed90f
CM		 3354 ret = -EIO;
3355 break;
0b86a832
CM		 3356 }
3357 ptr += len;
3358 sb_ptr += len;
3359 cur += len;
3360 }
a061fc8d 3361 free_extent_buffer(sb);
84eed90f 3362 return ret;
0b86a832
CM		 3363}
3364
3365int btrfs_read_chunk_tree(struct btrfs_root *root)
3366{
3367 struct btrfs_path *path;
3368 struct extent_buffer *leaf;
3369 struct btrfs_key key;
3370 struct btrfs_key found_key;
3371 int ret;
3372 int slot;
3373
3374 root = root->fs_info->chunk_root;
3375
3376 path = btrfs_alloc_path();
3377 if (!path)
3378 return -ENOMEM;
3379
3380 /* first we search for all of the device items, and then we
3381 * read in all of the chunk items. This way we can create chunk
3382 * mappings that reference all of the devices that are afound
3383 */
3384 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3385 key.offset = 0;
3386 key.type = 0;
3387again:
3388 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
ab59381e
ZL		 3389 if (ret < 0)
3390 goto error;
d397712b 3391 while (1) {
0b86a832
CM		 3392 leaf = path->nodes[0];
3393 slot = path->slots[0];
3394 if (slot >= btrfs_header_nritems(leaf)) {
3395 ret = btrfs_next_leaf(root, path);
3396 if (ret == 0)
3397 continue;
3398 if (ret < 0)
3399 goto error;
3400 break;
3401 }
3402 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3403 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3404 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3405 break;
3406 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3407 struct btrfs_dev_item *dev_item;
3408 dev_item = btrfs_item_ptr(leaf, slot,
3409 struct btrfs_dev_item);
0d81ba5d 3410 ret = read_one_dev(root, leaf, dev_item);
2b82032c
YZ		 3411 if (ret)
3412 goto error;
0b86a832
CM		 3413 }
3414 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3415 struct btrfs_chunk *chunk;
3416 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3417 ret = read_one_chunk(root, &found_key, leaf, chunk);
2b82032c
YZ		 3418 if (ret)
3419 goto error;
0b86a832
CM		 3420 }
3421 path->slots[0]++;
3422 }
3423 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3424 key.objectid = 0;
3425 btrfs_release_path(root, path);
3426 goto again;
3427 }
0b86a832
CM		 3428 ret = 0;
3429error:
2b82032c 3430 btrfs_free_path(path);
0b86a832
CM		 3431 return ret;
3432}
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