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>
  20#include <linux/slab.h>
  21#include <linux/buffer_head.h>
  22#include <linux/blkdev.h>
  23#include <linux/random.h>
  24#include <linux/iocontext.h>
  25#include <linux/capability.h>
  26#include <linux/ratelimit.h>
  27#include <linux/kthread.h>
  28#include <linux/raid/pq.h>
  29#include <linux/semaphore.h>
  30#include <asm/div64.h>
 
  31#include "ctree.h"
  32#include "extent_map.h"
  33#include "disk-io.h"
  34#include "transaction.h"
  35#include "print-tree.h"
  36#include "volumes.h"
  37#include "raid56.h"
  38#include "async-thread.h"
  39#include "check-integrity.h"
  40#include "rcu-string.h"
  41#include "math.h"
  42#include "dev-replace.h"
  43#include "sysfs.h"
  44
  45const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
  46	[BTRFS_RAID_RAID10] = {
  47		.sub_stripes	= 2,
  48		.dev_stripes	= 1,
  49		.devs_max	= 0,	/* 0 == as many as possible */
  50		.devs_min	= 4,
  51		.tolerated_failures = 1,
  52		.devs_increment	= 2,
  53		.ncopies	= 2,
  54	},
  55	[BTRFS_RAID_RAID1] = {
  56		.sub_stripes	= 1,
  57		.dev_stripes	= 1,
  58		.devs_max	= 2,
  59		.devs_min	= 2,
  60		.tolerated_failures = 1,
  61		.devs_increment	= 2,
  62		.ncopies	= 2,
  63	},
  64	[BTRFS_RAID_DUP] = {
  65		.sub_stripes	= 1,
  66		.dev_stripes	= 2,
  67		.devs_max	= 1,
  68		.devs_min	= 1,
  69		.tolerated_failures = 0,
  70		.devs_increment	= 1,
  71		.ncopies	= 2,
  72	},
  73	[BTRFS_RAID_RAID0] = {
  74		.sub_stripes	= 1,
  75		.dev_stripes	= 1,
  76		.devs_max	= 0,
  77		.devs_min	= 2,
  78		.tolerated_failures = 0,
  79		.devs_increment	= 1,
  80		.ncopies	= 1,
  81	},
  82	[BTRFS_RAID_SINGLE] = {
  83		.sub_stripes	= 1,
  84		.dev_stripes	= 1,
  85		.devs_max	= 1,
  86		.devs_min	= 1,
  87		.tolerated_failures = 0,
  88		.devs_increment	= 1,
  89		.ncopies	= 1,
  90	},
  91	[BTRFS_RAID_RAID5] = {
  92		.sub_stripes	= 1,
  93		.dev_stripes	= 1,
  94		.devs_max	= 0,
  95		.devs_min	= 2,
  96		.tolerated_failures = 1,
  97		.devs_increment	= 1,
  98		.ncopies	= 2,
  99	},
 100	[BTRFS_RAID_RAID6] = {
 101		.sub_stripes	= 1,
 102		.dev_stripes	= 1,
 103		.devs_max	= 0,
 104		.devs_min	= 3,
 105		.tolerated_failures = 2,
 106		.devs_increment	= 1,
 107		.ncopies	= 3,
 108	},
 109};
 110
 111const u64 btrfs_raid_group[BTRFS_NR_RAID_TYPES] = {
 112	[BTRFS_RAID_RAID10] = BTRFS_BLOCK_GROUP_RAID10,
 113	[BTRFS_RAID_RAID1]  = BTRFS_BLOCK_GROUP_RAID1,
 114	[BTRFS_RAID_DUP]    = BTRFS_BLOCK_GROUP_DUP,
 115	[BTRFS_RAID_RAID0]  = BTRFS_BLOCK_GROUP_RAID0,
 116	[BTRFS_RAID_SINGLE] = 0,
 117	[BTRFS_RAID_RAID5]  = BTRFS_BLOCK_GROUP_RAID5,
 118	[BTRFS_RAID_RAID6]  = BTRFS_BLOCK_GROUP_RAID6,
 119};
 120
 121static int init_first_rw_device(struct btrfs_trans_handle *trans,
 122				struct btrfs_root *root,
 123				struct btrfs_device *device);
 124static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
 125static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
 126static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
 127static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
 128static void btrfs_close_one_device(struct btrfs_device *device);
 129
 130DEFINE_MUTEX(uuid_mutex);
 131static LIST_HEAD(fs_uuids);
 132struct list_head *btrfs_get_fs_uuids(void)
 133{
 134	return &fs_uuids;
 135}
 136
 137static struct btrfs_fs_devices *__alloc_fs_devices(void)
 138{
 139	struct btrfs_fs_devices *fs_devs;
 140
 141	fs_devs = kzalloc(sizeof(*fs_devs), GFP_KERNEL);
 142	if (!fs_devs)
 143		return ERR_PTR(-ENOMEM);
 144
 145	mutex_init(&fs_devs->device_list_mutex);
 146
 147	INIT_LIST_HEAD(&fs_devs->devices);
 148	INIT_LIST_HEAD(&fs_devs->resized_devices);
 149	INIT_LIST_HEAD(&fs_devs->alloc_list);
 150	INIT_LIST_HEAD(&fs_devs->list);
 151
 152	return fs_devs;
 153}
 154
 155/**
 156 * alloc_fs_devices - allocate struct btrfs_fs_devices
 157 * @fsid:	a pointer to UUID for this FS.  If NULL a new UUID is
 158 *		generated.
 159 *
 160 * Return: a pointer to a new &struct btrfs_fs_devices on success;
 161 * ERR_PTR() on error.  Returned struct is not linked onto any lists and
 162 * can be destroyed with kfree() right away.
 163 */
 164static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid)
 165{
 166	struct btrfs_fs_devices *fs_devs;
 167
 168	fs_devs = __alloc_fs_devices();
 169	if (IS_ERR(fs_devs))
 170		return fs_devs;
 171
 172	if (fsid)
 173		memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
 174	else
 175		generate_random_uuid(fs_devs->fsid);
 176
 177	return fs_devs;
 178}
 179
 180static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
 181{
 182	struct btrfs_device *device;
 183	WARN_ON(fs_devices->opened);
 184	while (!list_empty(&fs_devices->devices)) {
 185		device = list_entry(fs_devices->devices.next,
 186				    struct btrfs_device, dev_list);
 187		list_del(&device->dev_list);
 188		rcu_string_free(device->name);
 189		kfree(device);
 190	}
 191	kfree(fs_devices);
 192}
 193
 194static void btrfs_kobject_uevent(struct block_device *bdev,
 195				 enum kobject_action action)
 196{
 197	int ret;
 198
 199	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
 200	if (ret)
 201		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
 202			action,
 203			kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
 204			&disk_to_dev(bdev->bd_disk)->kobj);
 205}
 206
 207void btrfs_cleanup_fs_uuids(void)
 208{
 209	struct btrfs_fs_devices *fs_devices;
 210
 211	while (!list_empty(&fs_uuids)) {
 212		fs_devices = list_entry(fs_uuids.next,
 213					struct btrfs_fs_devices, list);
 214		list_del(&fs_devices->list);
 215		free_fs_devices(fs_devices);
 216	}
 217}
 218
 219static struct btrfs_device *__alloc_device(void)
 220{
 221	struct btrfs_device *dev;
 222
 223	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 224	if (!dev)
 225		return ERR_PTR(-ENOMEM);
 226
 227	INIT_LIST_HEAD(&dev->dev_list);
 228	INIT_LIST_HEAD(&dev->dev_alloc_list);
 229	INIT_LIST_HEAD(&dev->resized_list);
 230
 231	spin_lock_init(&dev->io_lock);
 232
 233	spin_lock_init(&dev->reada_lock);
 234	atomic_set(&dev->reada_in_flight, 0);
 235	atomic_set(&dev->dev_stats_ccnt, 0);
 236	btrfs_device_data_ordered_init(dev);
 237	INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
 238	INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
 239
 240	return dev;
 241}
 242
 243static noinline struct btrfs_device *__find_device(struct list_head *head,
 244						   u64 devid, u8 *uuid)
 245{
 246	struct btrfs_device *dev;
 247
 248	list_for_each_entry(dev, head, dev_list) {
 249		if (dev->devid == devid &&
 250		    (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
 251			return dev;
 252		}
 253	}
 254	return NULL;
 255}
 256
 257static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
 258{
 259	struct btrfs_fs_devices *fs_devices;
 260
 261	list_for_each_entry(fs_devices, &fs_uuids, list) {
 262		if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
 263			return fs_devices;
 264	}
 265	return NULL;
 266}
 267
 268static int
 269btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
 270		      int flush, struct block_device **bdev,
 271		      struct buffer_head **bh)
 272{
 273	int ret;
 274
 275	*bdev = blkdev_get_by_path(device_path, flags, holder);
 276
 277	if (IS_ERR(*bdev)) {
 278		ret = PTR_ERR(*bdev);
 279		goto error;
 280	}
 281
 282	if (flush)
 283		filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
 284	ret = set_blocksize(*bdev, 4096);
 285	if (ret) {
 286		blkdev_put(*bdev, flags);
 287		goto error;
 288	}
 289	invalidate_bdev(*bdev);
 290	*bh = btrfs_read_dev_super(*bdev);
 291	if (IS_ERR(*bh)) {
 292		ret = PTR_ERR(*bh);
 293		blkdev_put(*bdev, flags);
 294		goto error;
 295	}
 296
 297	return 0;
 298
 299error:
 300	*bdev = NULL;
 301	*bh = NULL;
 302	return ret;
 303}
 304
 305static void requeue_list(struct btrfs_pending_bios *pending_bios,
 306			struct bio *head, struct bio *tail)
 307{
 308
 309	struct bio *old_head;
 310
 311	old_head = pending_bios->head;
 312	pending_bios->head = head;
 313	if (pending_bios->tail)
 314		tail->bi_next = old_head;
 315	else
 316		pending_bios->tail = tail;
 317}
 318
 319/*
 320 * we try to collect pending bios for a device so we don't get a large
 321 * number of procs sending bios down to the same device.  This greatly
 322 * improves the schedulers ability to collect and merge the bios.
 323 *
 324 * But, it also turns into a long list of bios to process and that is sure
 325 * to eventually make the worker thread block.  The solution here is to
 326 * make some progress and then put this work struct back at the end of
 327 * the list if the block device is congested.  This way, multiple devices
 328 * can make progress from a single worker thread.
 329 */
 330static noinline void run_scheduled_bios(struct btrfs_device *device)
 331{
 332	struct bio *pending;
 333	struct backing_dev_info *bdi;
 334	struct btrfs_fs_info *fs_info;
 335	struct btrfs_pending_bios *pending_bios;
 336	struct bio *tail;
 337	struct bio *cur;
 338	int again = 0;
 339	unsigned long num_run;
 340	unsigned long batch_run = 0;
 341	unsigned long limit;
 342	unsigned long last_waited = 0;
 343	int force_reg = 0;
 344	int sync_pending = 0;
 345	struct blk_plug plug;
 346
 347	/*
 348	 * this function runs all the bios we've collected for
 349	 * a particular device.  We don't want to wander off to
 350	 * another device without first sending all of these down.
 351	 * So, setup a plug here and finish it off before we return
 352	 */
 353	blk_start_plug(&plug);
 354
 355	bdi = blk_get_backing_dev_info(device->bdev);
 356	fs_info = device->dev_root->fs_info;
 357	limit = btrfs_async_submit_limit(fs_info);
 358	limit = limit * 2 / 3;
 359
 360loop:
 361	spin_lock(&device->io_lock);
 362
 363loop_lock:
 364	num_run = 0;
 365
 366	/* take all the bios off the list at once and process them
 367	 * later on (without the lock held).  But, remember the
 368	 * tail and other pointers so the bios can be properly reinserted
 369	 * into the list if we hit congestion
 370	 */
 371	if (!force_reg && device->pending_sync_bios.head) {
 372		pending_bios = &device->pending_sync_bios;
 373		force_reg = 1;
 374	} else {
 375		pending_bios = &device->pending_bios;
 376		force_reg = 0;
 377	}
 378
 379	pending = pending_bios->head;
 380	tail = pending_bios->tail;
 381	WARN_ON(pending && !tail);
 382
 383	/*
 384	 * if pending was null this time around, no bios need processing
 385	 * at all and we can stop.  Otherwise it'll loop back up again
 386	 * and do an additional check so no bios are missed.
 387	 *
 388	 * device->running_pending is used to synchronize with the
 389	 * schedule_bio code.
 390	 */
 391	if (device->pending_sync_bios.head == NULL &&
 392	    device->pending_bios.head == NULL) {
 393		again = 0;
 394		device->running_pending = 0;
 395	} else {
 396		again = 1;
 397		device->running_pending = 1;
 398	}
 399
 400	pending_bios->head = NULL;
 401	pending_bios->tail = NULL;
 402
 403	spin_unlock(&device->io_lock);
 404
 405	while (pending) {
 406
 407		rmb();
 408		/* we want to work on both lists, but do more bios on the
 409		 * sync list than the regular list
 410		 */
 411		if ((num_run > 32 &&
 412		    pending_bios != &device->pending_sync_bios &&
 413		    device->pending_sync_bios.head) ||
 414		   (num_run > 64 && pending_bios == &device->pending_sync_bios &&
 415		    device->pending_bios.head)) {
 416			spin_lock(&device->io_lock);
 417			requeue_list(pending_bios, pending, tail);
 418			goto loop_lock;
 419		}
 420
 421		cur = pending;
 422		pending = pending->bi_next;
 423		cur->bi_next = NULL;
 
 424
 425		/*
 426		 * atomic_dec_return implies a barrier for waitqueue_active
 427		 */
 428		if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
 429		    waitqueue_active(&fs_info->async_submit_wait))
 430			wake_up(&fs_info->async_submit_wait);
 431
 432		BUG_ON(atomic_read(&cur->__bi_cnt) == 0);
 433
 434		/*
 435		 * if we're doing the sync list, record that our
 436		 * plug has some sync requests on it
 437		 *
 438		 * If we're doing the regular list and there are
 439		 * sync requests sitting around, unplug before
 440		 * we add more
 441		 */
 442		if (pending_bios == &device->pending_sync_bios) {
 443			sync_pending = 1;
 444		} else if (sync_pending) {
 445			blk_finish_plug(&plug);
 446			blk_start_plug(&plug);
 447			sync_pending = 0;
 448		}
 449
 450		btrfsic_submit_bio(cur->bi_rw, cur);
 451		num_run++;
 452		batch_run++;
 453
 454		cond_resched();
 455
 456		/*
 457		 * we made progress, there is more work to do and the bdi
 458		 * is now congested.  Back off and let other work structs
 459		 * run instead
 460		 */
 461		if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
 462		    fs_info->fs_devices->open_devices > 1) {
 463			struct io_context *ioc;
 464
 465			ioc = current->io_context;
 466
 467			/*
 468			 * the main goal here is that we don't want to
 469			 * block if we're going to be able to submit
 470			 * more requests without blocking.
 471			 *
 472			 * This code does two great things, it pokes into
 473			 * the elevator code from a filesystem _and_
 474			 * it makes assumptions about how batching works.
 475			 */
 476			if (ioc && ioc->nr_batch_requests > 0 &&
 477			    time_before(jiffies, ioc->last_waited + HZ/50UL) &&
 478			    (last_waited == 0 ||
 479			     ioc->last_waited == last_waited)) {
 480				/*
 481				 * we want to go through our batch of
 482				 * requests and stop.  So, we copy out
 483				 * the ioc->last_waited time and test
 484				 * against it before looping
 485				 */
 486				last_waited = ioc->last_waited;
 487				cond_resched();
 
 488				continue;
 489			}
 490			spin_lock(&device->io_lock);
 491			requeue_list(pending_bios, pending, tail);
 492			device->running_pending = 1;
 493
 494			spin_unlock(&device->io_lock);
 495			btrfs_queue_work(fs_info->submit_workers,
 496					 &device->work);
 497			goto done;
 498		}
 499		/* unplug every 64 requests just for good measure */
 500		if (batch_run % 64 == 0) {
 501			blk_finish_plug(&plug);
 502			blk_start_plug(&plug);
 503			sync_pending = 0;
 504		}
 505	}
 506
 507	cond_resched();
 508	if (again)
 509		goto loop;
 510
 511	spin_lock(&device->io_lock);
 512	if (device->pending_bios.head || device->pending_sync_bios.head)
 513		goto loop_lock;
 514	spin_unlock(&device->io_lock);
 515
 516done:
 517	blk_finish_plug(&plug);
 518}
 519
 520static void pending_bios_fn(struct btrfs_work *work)
 521{
 522	struct btrfs_device *device;
 523
 524	device = container_of(work, struct btrfs_device, work);
 525	run_scheduled_bios(device);
 526}
 527
 528
 529void btrfs_free_stale_device(struct btrfs_device *cur_dev)
 530{
 531	struct btrfs_fs_devices *fs_devs;
 532	struct btrfs_device *dev;
 533
 534	if (!cur_dev->name)
 535		return;
 536
 537	list_for_each_entry(fs_devs, &fs_uuids, list) {
 538		int del = 1;
 539
 540		if (fs_devs->opened)
 541			continue;
 542		if (fs_devs->seeding)
 543			continue;
 544
 545		list_for_each_entry(dev, &fs_devs->devices, dev_list) {
 546
 547			if (dev == cur_dev)
 548				continue;
 549			if (!dev->name)
 550				continue;
 551
 552			/*
 553			 * Todo: This won't be enough. What if the same device
 554			 * comes back (with new uuid and) with its mapper path?
 555			 * But for now, this does help as mostly an admin will
 556			 * either use mapper or non mapper path throughout.
 557			 */
 558			rcu_read_lock();
 559			del = strcmp(rcu_str_deref(dev->name),
 560						rcu_str_deref(cur_dev->name));
 561			rcu_read_unlock();
 562			if (!del)
 563				break;
 564		}
 565
 566		if (!del) {
 567			/* delete the stale device */
 568			if (fs_devs->num_devices == 1) {
 569				btrfs_sysfs_remove_fsid(fs_devs);
 570				list_del(&fs_devs->list);
 571				free_fs_devices(fs_devs);
 572			} else {
 573				fs_devs->num_devices--;
 574				list_del(&dev->dev_list);
 575				rcu_string_free(dev->name);
 576				kfree(dev);
 577			}
 578			break;
 579		}
 580	}
 581}
 582
 583/*
 584 * Add new device to list of registered devices
 585 *
 586 * Returns:
 587 * 1   - first time device is seen
 588 * 0   - device already known
 589 * < 0 - error
 590 */
 591static noinline int device_list_add(const char *path,
 592			   struct btrfs_super_block *disk_super,
 593			   u64 devid, struct btrfs_fs_devices **fs_devices_ret)
 594{
 595	struct btrfs_device *device;
 596	struct btrfs_fs_devices *fs_devices;
 597	struct rcu_string *name;
 598	int ret = 0;
 599	u64 found_transid = btrfs_super_generation(disk_super);
 600
 601	fs_devices = find_fsid(disk_super->fsid);
 602	if (!fs_devices) {
 603		fs_devices = alloc_fs_devices(disk_super->fsid);
 604		if (IS_ERR(fs_devices))
 605			return PTR_ERR(fs_devices);
 606
 
 607		list_add(&fs_devices->list, &fs_uuids);
 608
 
 
 
 609		device = NULL;
 610	} else {
 611		device = __find_device(&fs_devices->devices, devid,
 612				       disk_super->dev_item.uuid);
 613	}
 614
 615	if (!device) {
 616		if (fs_devices->opened)
 617			return -EBUSY;
 618
 619		device = btrfs_alloc_device(NULL, &devid,
 620					    disk_super->dev_item.uuid);
 621		if (IS_ERR(device)) {
 622			/* we can safely leave the fs_devices entry around */
 623			return PTR_ERR(device);
 624		}
 
 
 
 
 
 
 625
 626		name = rcu_string_strdup(path, GFP_NOFS);
 627		if (!name) {
 628			kfree(device);
 629			return -ENOMEM;
 630		}
 631		rcu_assign_pointer(device->name, name);
 
 
 
 
 
 
 
 
 
 632
 633		mutex_lock(&fs_devices->device_list_mutex);
 634		list_add_rcu(&device->dev_list, &fs_devices->devices);
 635		fs_devices->num_devices++;
 636		mutex_unlock(&fs_devices->device_list_mutex);
 637
 638		ret = 1;
 639		device->fs_devices = fs_devices;
 
 640	} else if (!device->name || strcmp(device->name->str, path)) {
 641		/*
 642		 * When FS is already mounted.
 643		 * 1. If you are here and if the device->name is NULL that
 644		 *    means this device was missing at time of FS mount.
 645		 * 2. If you are here and if the device->name is different
 646		 *    from 'path' that means either
 647		 *      a. The same device disappeared and reappeared with
 648		 *         different name. or
 649		 *      b. The missing-disk-which-was-replaced, has
 650		 *         reappeared now.
 651		 *
 652		 * We must allow 1 and 2a above. But 2b would be a spurious
 653		 * and unintentional.
 654		 *
 655		 * Further in case of 1 and 2a above, the disk at 'path'
 656		 * would have missed some transaction when it was away and
 657		 * in case of 2a the stale bdev has to be updated as well.
 658		 * 2b must not be allowed at all time.
 659		 */
 660
 661		/*
 662		 * For now, we do allow update to btrfs_fs_device through the
 663		 * btrfs dev scan cli after FS has been mounted.  We're still
 664		 * tracking a problem where systems fail mount by subvolume id
 665		 * when we reject replacement on a mounted FS.
 666		 */
 667		if (!fs_devices->opened && found_transid < device->generation) {
 668			/*
 669			 * That is if the FS is _not_ mounted and if you
 670			 * are here, that means there is more than one
 671			 * disk with same uuid and devid.We keep the one
 672			 * with larger generation number or the last-in if
 673			 * generation are equal.
 674			 */
 675			return -EEXIST;
 676		}
 677
 678		name = rcu_string_strdup(path, GFP_NOFS);
 679		if (!name)
 680			return -ENOMEM;
 681		rcu_string_free(device->name);
 682		rcu_assign_pointer(device->name, name);
 683		if (device->missing) {
 684			fs_devices->missing_devices--;
 685			device->missing = 0;
 686		}
 687	}
 688
 689	/*
 690	 * Unmount does not free the btrfs_device struct but would zero
 691	 * generation along with most of the other members. So just update
 692	 * it back. We need it to pick the disk with largest generation
 693	 * (as above).
 694	 */
 695	if (!fs_devices->opened)
 696		device->generation = found_transid;
 697
 698	/*
 699	 * if there is new btrfs on an already registered device,
 700	 * then remove the stale device entry.
 701	 */
 702	btrfs_free_stale_device(device);
 703
 704	*fs_devices_ret = fs_devices;
 705
 706	return ret;
 707}
 708
 709static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
 710{
 711	struct btrfs_fs_devices *fs_devices;
 712	struct btrfs_device *device;
 713	struct btrfs_device *orig_dev;
 714
 715	fs_devices = alloc_fs_devices(orig->fsid);
 716	if (IS_ERR(fs_devices))
 717		return fs_devices;
 718
 719	mutex_lock(&orig->device_list_mutex);
 720	fs_devices->total_devices = orig->total_devices;
 
 
 
 
 
 721
 722	/* We have held the volume lock, it is safe to get the devices. */
 723	list_for_each_entry(orig_dev, &orig->devices, dev_list) {
 724		struct rcu_string *name;
 725
 726		device = btrfs_alloc_device(NULL, &orig_dev->devid,
 727					    orig_dev->uuid);
 728		if (IS_ERR(device))
 729			goto error;
 730
 731		/*
 732		 * This is ok to do without rcu read locked because we hold the
 733		 * uuid mutex so nothing we touch in here is going to disappear.
 734		 */
 735		if (orig_dev->name) {
 736			name = rcu_string_strdup(orig_dev->name->str,
 737					GFP_KERNEL);
 738			if (!name) {
 739				kfree(device);
 740				goto error;
 741			}
 742			rcu_assign_pointer(device->name, name);
 743		}
 
 
 
 
 
 
 
 
 744
 745		list_add(&device->dev_list, &fs_devices->devices);
 746		device->fs_devices = fs_devices;
 747		fs_devices->num_devices++;
 748	}
 749	mutex_unlock(&orig->device_list_mutex);
 750	return fs_devices;
 751error:
 752	mutex_unlock(&orig->device_list_mutex);
 753	free_fs_devices(fs_devices);
 754	return ERR_PTR(-ENOMEM);
 755}
 756
 757void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step)
 758{
 759	struct btrfs_device *device, *next;
 760	struct btrfs_device *latest_dev = NULL;
 
 
 
 761
 762	mutex_lock(&uuid_mutex);
 763again:
 764	/* This is the initialized path, it is safe to release the devices. */
 765	list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
 766		if (device->in_fs_metadata) {
 767			if (!device->is_tgtdev_for_dev_replace &&
 768			    (!latest_dev ||
 769			     device->generation > latest_dev->generation)) {
 770				latest_dev = device;
 
 771			}
 772			continue;
 773		}
 774
 775		if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
 776			/*
 777			 * In the first step, keep the device which has
 778			 * the correct fsid and the devid that is used
 779			 * for the dev_replace procedure.
 780			 * In the second step, the dev_replace state is
 781			 * read from the device tree and it is known
 782			 * whether the procedure is really active or
 783			 * not, which means whether this device is
 784			 * used or whether it should be removed.
 785			 */
 786			if (step == 0 || device->is_tgtdev_for_dev_replace) {
 787				continue;
 788			}
 789		}
 790		if (device->bdev) {
 791			blkdev_put(device->bdev, device->mode);
 792			device->bdev = NULL;
 793			fs_devices->open_devices--;
 794		}
 795		if (device->writeable) {
 796			list_del_init(&device->dev_alloc_list);
 797			device->writeable = 0;
 798			if (!device->is_tgtdev_for_dev_replace)
 799				fs_devices->rw_devices--;
 800		}
 801		list_del_init(&device->dev_list);
 802		fs_devices->num_devices--;
 803		rcu_string_free(device->name);
 804		kfree(device);
 805	}
 806
 807	if (fs_devices->seed) {
 808		fs_devices = fs_devices->seed;
 809		goto again;
 810	}
 811
 812	fs_devices->latest_bdev = latest_dev->bdev;
 
 
 813
 814	mutex_unlock(&uuid_mutex);
 815}
 816
 817static void __free_device(struct work_struct *work)
 818{
 819	struct btrfs_device *device;
 820
 821	device = container_of(work, struct btrfs_device, rcu_work);
 822
 823	if (device->bdev)
 824		blkdev_put(device->bdev, device->mode);
 825
 826	rcu_string_free(device->name);
 827	kfree(device);
 828}
 829
 830static void free_device(struct rcu_head *head)
 831{
 832	struct btrfs_device *device;
 833
 834	device = container_of(head, struct btrfs_device, rcu);
 835
 836	INIT_WORK(&device->rcu_work, __free_device);
 837	schedule_work(&device->rcu_work);
 838}
 839
 840static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 841{
 842	struct btrfs_device *device, *tmp;
 843
 844	if (--fs_devices->opened > 0)
 845		return 0;
 846
 847	mutex_lock(&fs_devices->device_list_mutex);
 848	list_for_each_entry_safe(device, tmp, &fs_devices->devices, dev_list) {
 849		btrfs_close_one_device(device);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 850	}
 851	mutex_unlock(&fs_devices->device_list_mutex);
 852
 853	WARN_ON(fs_devices->open_devices);
 854	WARN_ON(fs_devices->rw_devices);
 855	fs_devices->opened = 0;
 856	fs_devices->seeding = 0;
 857
 858	return 0;
 859}
 860
 861int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 862{
 863	struct btrfs_fs_devices *seed_devices = NULL;
 864	int ret;
 865
 866	mutex_lock(&uuid_mutex);
 867	ret = __btrfs_close_devices(fs_devices);
 868	if (!fs_devices->opened) {
 869		seed_devices = fs_devices->seed;
 870		fs_devices->seed = NULL;
 871	}
 872	mutex_unlock(&uuid_mutex);
 873
 874	while (seed_devices) {
 875		fs_devices = seed_devices;
 876		seed_devices = fs_devices->seed;
 877		__btrfs_close_devices(fs_devices);
 878		free_fs_devices(fs_devices);
 879	}
 880	/*
 881	 * Wait for rcu kworkers under __btrfs_close_devices
 882	 * to finish all blkdev_puts so device is really
 883	 * free when umount is done.
 884	 */
 885	rcu_barrier();
 886	return ret;
 887}
 888
 889static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 890				fmode_t flags, void *holder)
 891{
 892	struct request_queue *q;
 893	struct block_device *bdev;
 894	struct list_head *head = &fs_devices->devices;
 895	struct btrfs_device *device;
 896	struct btrfs_device *latest_dev = NULL;
 897	struct buffer_head *bh;
 898	struct btrfs_super_block *disk_super;
 
 
 899	u64 devid;
 900	int seeding = 1;
 901	int ret = 0;
 902
 903	flags |= FMODE_EXCL;
 904
 905	list_for_each_entry(device, head, dev_list) {
 906		if (device->bdev)
 907			continue;
 908		if (!device->name)
 909			continue;
 910
 911		/* Just open everything we can; ignore failures here */
 912		if (btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
 913					    &bdev, &bh))
 914			continue;
 
 
 
 
 
 
 
 
 915
 916		disk_super = (struct btrfs_super_block *)bh->b_data;
 917		devid = btrfs_stack_device_id(&disk_super->dev_item);
 918		if (devid != device->devid)
 919			goto error_brelse;
 920
 921		if (memcmp(device->uuid, disk_super->dev_item.uuid,
 922			   BTRFS_UUID_SIZE))
 923			goto error_brelse;
 924
 925		device->generation = btrfs_super_generation(disk_super);
 926		if (!latest_dev ||
 927		    device->generation > latest_dev->generation)
 928			latest_dev = device;
 
 
 929
 930		if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
 931			device->writeable = 0;
 932		} else {
 933			device->writeable = !bdev_read_only(bdev);
 934			seeding = 0;
 935		}
 936
 937		q = bdev_get_queue(bdev);
 938		if (blk_queue_discard(q))
 939			device->can_discard = 1;
 
 
 940
 941		device->bdev = bdev;
 942		device->in_fs_metadata = 0;
 943		device->mode = flags;
 944
 945		if (!blk_queue_nonrot(bdev_get_queue(bdev)))
 946			fs_devices->rotating = 1;
 947
 948		fs_devices->open_devices++;
 949		if (device->writeable &&
 950		    device->devid != BTRFS_DEV_REPLACE_DEVID) {
 951			fs_devices->rw_devices++;
 952			list_add(&device->dev_alloc_list,
 953				 &fs_devices->alloc_list);
 954		}
 955		brelse(bh);
 956		continue;
 957
 958error_brelse:
 959		brelse(bh);
 
 960		blkdev_put(bdev, flags);
 
 961		continue;
 962	}
 963	if (fs_devices->open_devices == 0) {
 964		ret = -EINVAL;
 965		goto out;
 966	}
 967	fs_devices->seeding = seeding;
 968	fs_devices->opened = 1;
 969	fs_devices->latest_bdev = latest_dev->bdev;
 
 
 970	fs_devices->total_rw_bytes = 0;
 971out:
 972	return ret;
 973}
 974
 975int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 976		       fmode_t flags, void *holder)
 977{
 978	int ret;
 979
 980	mutex_lock(&uuid_mutex);
 981	if (fs_devices->opened) {
 982		fs_devices->opened++;
 983		ret = 0;
 984	} else {
 985		ret = __btrfs_open_devices(fs_devices, flags, holder);
 986	}
 987	mutex_unlock(&uuid_mutex);
 988	return ret;
 989}
 990
 991/*
 992 * Look for a btrfs signature on a device. This may be called out of the mount path
 993 * and we are not allowed to call set_blocksize during the scan. The superblock
 994 * is read via pagecache
 995 */
 996int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 997			  struct btrfs_fs_devices **fs_devices_ret)
 998{
 999	struct btrfs_super_block *disk_super;
1000	struct block_device *bdev;
1001	struct page *page;
1002	void *p;
1003	int ret = -EINVAL;
1004	u64 devid;
1005	u64 transid;
1006	u64 total_devices;
1007	u64 bytenr;
1008	pgoff_t index;
1009
1010	/*
1011	 * we would like to check all the supers, but that would make
1012	 * a btrfs mount succeed after a mkfs from a different FS.
1013	 * So, we need to add a special mount option to scan for
1014	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
1015	 */
1016	bytenr = btrfs_sb_offset(0);
1017	flags |= FMODE_EXCL;
1018	mutex_lock(&uuid_mutex);
1019
1020	bdev = blkdev_get_by_path(path, flags, holder);
1021
1022	if (IS_ERR(bdev)) {
1023		ret = PTR_ERR(bdev);
1024		goto error;
1025	}
1026
1027	/* make sure our super fits in the device */
1028	if (bytenr + PAGE_SIZE >= i_size_read(bdev->bd_inode))
1029		goto error_bdev_put;
1030
1031	/* make sure our super fits in the page */
1032	if (sizeof(*disk_super) > PAGE_SIZE)
1033		goto error_bdev_put;
1034
1035	/* make sure our super doesn't straddle pages on disk */
1036	index = bytenr >> PAGE_SHIFT;
1037	if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_SHIFT != index)
1038		goto error_bdev_put;
1039
1040	/* pull in the page with our super */
1041	page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
1042				   index, GFP_NOFS);
1043
1044	if (IS_ERR_OR_NULL(page))
1045		goto error_bdev_put;
1046
1047	p = kmap(page);
1048
1049	/* align our pointer to the offset of the super block */
1050	disk_super = p + (bytenr & ~PAGE_MASK);
1051
1052	if (btrfs_super_bytenr(disk_super) != bytenr ||
1053	    btrfs_super_magic(disk_super) != BTRFS_MAGIC)
1054		goto error_unmap;
1055
1056	devid = btrfs_stack_device_id(&disk_super->dev_item);
1057	transid = btrfs_super_generation(disk_super);
1058	total_devices = btrfs_super_num_devices(disk_super);
1059
 
 
 
 
1060	ret = device_list_add(path, disk_super, devid, fs_devices_ret);
1061	if (ret > 0) {
1062		if (disk_super->label[0]) {
1063			if (disk_super->label[BTRFS_LABEL_SIZE - 1])
1064				disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
1065			printk(KERN_INFO "BTRFS: device label %s ", disk_super->label);
1066		} else {
1067			printk(KERN_INFO "BTRFS: device fsid %pU ", disk_super->fsid);
1068		}
1069
1070		printk(KERN_CONT "devid %llu transid %llu %s\n", devid, transid, path);
1071		ret = 0;
1072	}
1073	if (!ret && fs_devices_ret)
1074		(*fs_devices_ret)->total_devices = total_devices;
1075
1076error_unmap:
1077	kunmap(page);
1078	put_page(page);
1079
1080error_bdev_put:
 
 
1081	blkdev_put(bdev, flags);
1082error:
1083	mutex_unlock(&uuid_mutex);
1084	return ret;
1085}
1086
1087/* helper to account the used device space in the range */
1088int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
1089				   u64 end, u64 *length)
1090{
1091	struct btrfs_key key;
1092	struct btrfs_root *root = device->dev_root;
1093	struct btrfs_dev_extent *dev_extent;
1094	struct btrfs_path *path;
1095	u64 extent_end;
1096	int ret;
1097	int slot;
1098	struct extent_buffer *l;
1099
1100	*length = 0;
1101
1102	if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
1103		return 0;
1104
1105	path = btrfs_alloc_path();
1106	if (!path)
1107		return -ENOMEM;
1108	path->reada = READA_FORWARD;
1109
1110	key.objectid = device->devid;
1111	key.offset = start;
1112	key.type = BTRFS_DEV_EXTENT_KEY;
1113
1114	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1115	if (ret < 0)
1116		goto out;
1117	if (ret > 0) {
1118		ret = btrfs_previous_item(root, path, key.objectid, key.type);
1119		if (ret < 0)
1120			goto out;
1121	}
1122
1123	while (1) {
1124		l = path->nodes[0];
1125		slot = path->slots[0];
1126		if (slot >= btrfs_header_nritems(l)) {
1127			ret = btrfs_next_leaf(root, path);
1128			if (ret == 0)
1129				continue;
1130			if (ret < 0)
1131				goto out;
1132
1133			break;
1134		}
1135		btrfs_item_key_to_cpu(l, &key, slot);
1136
1137		if (key.objectid < device->devid)
1138			goto next;
1139
1140		if (key.objectid > device->devid)
1141			break;
1142
1143		if (key.type != BTRFS_DEV_EXTENT_KEY)
1144			goto next;
1145
1146		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1147		extent_end = key.offset + btrfs_dev_extent_length(l,
1148								  dev_extent);
1149		if (key.offset <= start && extent_end > end) {
1150			*length = end - start + 1;
1151			break;
1152		} else if (key.offset <= start && extent_end > start)
1153			*length += extent_end - start;
1154		else if (key.offset > start && extent_end <= end)
1155			*length += extent_end - key.offset;
1156		else if (key.offset > start && key.offset <= end) {
1157			*length += end - key.offset + 1;
1158			break;
1159		} else if (key.offset > end)
1160			break;
1161
1162next:
1163		path->slots[0]++;
1164	}
1165	ret = 0;
1166out:
1167	btrfs_free_path(path);
1168	return ret;
1169}
1170
1171static int contains_pending_extent(struct btrfs_transaction *transaction,
1172				   struct btrfs_device *device,
1173				   u64 *start, u64 len)
1174{
1175	struct btrfs_fs_info *fs_info = device->dev_root->fs_info;
1176	struct extent_map *em;
1177	struct list_head *search_list = &fs_info->pinned_chunks;
1178	int ret = 0;
1179	u64 physical_start = *start;
1180
1181	if (transaction)
1182		search_list = &transaction->pending_chunks;
1183again:
1184	list_for_each_entry(em, search_list, list) {
1185		struct map_lookup *map;
1186		int i;
1187
1188		map = em->map_lookup;
1189		for (i = 0; i < map->num_stripes; i++) {
1190			u64 end;
1191
1192			if (map->stripes[i].dev != device)
1193				continue;
1194			if (map->stripes[i].physical >= physical_start + len ||
1195			    map->stripes[i].physical + em->orig_block_len <=
1196			    physical_start)
1197				continue;
1198			/*
1199			 * Make sure that while processing the pinned list we do
1200			 * not override our *start with a lower value, because
1201			 * we can have pinned chunks that fall within this
1202			 * device hole and that have lower physical addresses
1203			 * than the pending chunks we processed before. If we
1204			 * do not take this special care we can end up getting
1205			 * 2 pending chunks that start at the same physical
1206			 * device offsets because the end offset of a pinned
1207			 * chunk can be equal to the start offset of some
1208			 * pending chunk.
1209			 */
1210			end = map->stripes[i].physical + em->orig_block_len;
1211			if (end > *start) {
1212				*start = end;
1213				ret = 1;
1214			}
1215		}
1216	}
1217	if (search_list != &fs_info->pinned_chunks) {
1218		search_list = &fs_info->pinned_chunks;
1219		goto again;
1220	}
1221
1222	return ret;
1223}
1224
1225
1226/*
1227 * find_free_dev_extent_start - find free space in the specified device
1228 * @device:	  the device which we search the free space in
1229 * @num_bytes:	  the size of the free space that we need
1230 * @search_start: the position from which to begin the search
1231 * @start:	  store the start of the free space.
1232 * @len:	  the size of the free space. that we find, or the size
1233 *		  of the max free space if we don't find suitable free space
1234 *
1235 * this uses a pretty simple search, the expectation is that it is
1236 * called very infrequently and that a given device has a small number
1237 * of extents
1238 *
1239 * @start is used to store the start of the free space if we find. But if we
1240 * don't find suitable free space, it will be used to store the start position
1241 * of the max free space.
1242 *
1243 * @len is used to store the size of the free space that we find.
1244 * But if we don't find suitable free space, it is used to store the size of
1245 * the max free space.
1246 */
1247int find_free_dev_extent_start(struct btrfs_transaction *transaction,
1248			       struct btrfs_device *device, u64 num_bytes,
1249			       u64 search_start, u64 *start, u64 *len)
1250{
1251	struct btrfs_key key;
1252	struct btrfs_root *root = device->dev_root;
1253	struct btrfs_dev_extent *dev_extent;
1254	struct btrfs_path *path;
1255	u64 hole_size;
1256	u64 max_hole_start;
1257	u64 max_hole_size;
1258	u64 extent_end;
 
1259	u64 search_end = device->total_bytes;
1260	int ret;
1261	int slot;
1262	struct extent_buffer *l;
1263	u64 min_search_start;
1264
1265	/*
1266	 * We don't want to overwrite the superblock on the drive nor any area
1267	 * used by the boot loader (grub for example), so we make sure to start
1268	 * at an offset of at least 1MB.
1269	 */
1270	min_search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
1271	search_start = max(search_start, min_search_start);
1272
1273	path = btrfs_alloc_path();
1274	if (!path)
1275		return -ENOMEM;
 
1276
1277	max_hole_start = search_start;
1278	max_hole_size = 0;
 
1279
1280again:
1281	if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
1282		ret = -ENOSPC;
1283		goto out;
1284	}
1285
1286	path->reada = READA_FORWARD;
1287	path->search_commit_root = 1;
1288	path->skip_locking = 1;
 
 
 
1289
1290	key.objectid = device->devid;
1291	key.offset = search_start;
1292	key.type = BTRFS_DEV_EXTENT_KEY;
1293
1294	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1295	if (ret < 0)
1296		goto out;
1297	if (ret > 0) {
1298		ret = btrfs_previous_item(root, path, key.objectid, key.type);
1299		if (ret < 0)
1300			goto out;
1301	}
1302
1303	while (1) {
1304		l = path->nodes[0];
1305		slot = path->slots[0];
1306		if (slot >= btrfs_header_nritems(l)) {
1307			ret = btrfs_next_leaf(root, path);
1308			if (ret == 0)
1309				continue;
1310			if (ret < 0)
1311				goto out;
1312
1313			break;
1314		}
1315		btrfs_item_key_to_cpu(l, &key, slot);
1316
1317		if (key.objectid < device->devid)
1318			goto next;
1319
1320		if (key.objectid > device->devid)
1321			break;
1322
1323		if (key.type != BTRFS_DEV_EXTENT_KEY)
1324			goto next;
1325
1326		if (key.offset > search_start) {
1327			hole_size = key.offset - search_start;
1328
1329			/*
1330			 * Have to check before we set max_hole_start, otherwise
1331			 * we could end up sending back this offset anyway.
1332			 */
1333			if (contains_pending_extent(transaction, device,
1334						    &search_start,
1335						    hole_size)) {
1336				if (key.offset >= search_start) {
1337					hole_size = key.offset - search_start;
1338				} else {
1339					WARN_ON_ONCE(1);
1340					hole_size = 0;
1341				}
1342			}
1343
1344			if (hole_size > max_hole_size) {
1345				max_hole_start = search_start;
1346				max_hole_size = hole_size;
1347			}
1348
1349			/*
1350			 * If this free space is greater than which we need,
1351			 * it must be the max free space that we have found
1352			 * until now, so max_hole_start must point to the start
1353			 * of this free space and the length of this free space
1354			 * is stored in max_hole_size. Thus, we return
1355			 * max_hole_start and max_hole_size and go back to the
1356			 * caller.
1357			 */
1358			if (hole_size >= num_bytes) {
1359				ret = 0;
1360				goto out;
1361			}
1362		}
1363
1364		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1365		extent_end = key.offset + btrfs_dev_extent_length(l,
1366								  dev_extent);
1367		if (extent_end > search_start)
1368			search_start = extent_end;
1369next:
1370		path->slots[0]++;
1371		cond_resched();
1372	}
1373
1374	/*
1375	 * At this point, search_start should be the end of
1376	 * allocated dev extents, and when shrinking the device,
1377	 * search_end may be smaller than search_start.
1378	 */
1379	if (search_end > search_start) {
1380		hole_size = search_end - search_start;
1381
1382		if (contains_pending_extent(transaction, device, &search_start,
1383					    hole_size)) {
1384			btrfs_release_path(path);
1385			goto again;
1386		}
1387
1388		if (hole_size > max_hole_size) {
1389			max_hole_start = search_start;
1390			max_hole_size = hole_size;
1391		}
1392	}
1393
1394	/* See above. */
1395	if (max_hole_size < num_bytes)
1396		ret = -ENOSPC;
1397	else
1398		ret = 0;
1399
1400out:
1401	btrfs_free_path(path);
 
1402	*start = max_hole_start;
1403	if (len)
1404		*len = max_hole_size;
1405	return ret;
1406}
1407
1408int find_free_dev_extent(struct btrfs_trans_handle *trans,
1409			 struct btrfs_device *device, u64 num_bytes,
1410			 u64 *start, u64 *len)
1411{
1412	/* FIXME use last free of some kind */
1413	return find_free_dev_extent_start(trans->transaction, device,
1414					  num_bytes, 0, start, len);
1415}
1416
1417static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1418			  struct btrfs_device *device,
1419			  u64 start, u64 *dev_extent_len)
1420{
1421	int ret;
1422	struct btrfs_path *path;
1423	struct btrfs_root *root = device->dev_root;
1424	struct btrfs_key key;
1425	struct btrfs_key found_key;
1426	struct extent_buffer *leaf = NULL;
1427	struct btrfs_dev_extent *extent = NULL;
1428
1429	path = btrfs_alloc_path();
1430	if (!path)
1431		return -ENOMEM;
1432
1433	key.objectid = device->devid;
1434	key.offset = start;
1435	key.type = BTRFS_DEV_EXTENT_KEY;
1436again:
1437	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1438	if (ret > 0) {
1439		ret = btrfs_previous_item(root, path, key.objectid,
1440					  BTRFS_DEV_EXTENT_KEY);
1441		if (ret)
1442			goto out;
1443		leaf = path->nodes[0];
1444		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1445		extent = btrfs_item_ptr(leaf, path->slots[0],
1446					struct btrfs_dev_extent);
1447		BUG_ON(found_key.offset > start || found_key.offset +
1448		       btrfs_dev_extent_length(leaf, extent) < start);
1449		key = found_key;
1450		btrfs_release_path(path);
1451		goto again;
1452	} else if (ret == 0) {
1453		leaf = path->nodes[0];
1454		extent = btrfs_item_ptr(leaf, path->slots[0],
1455					struct btrfs_dev_extent);
1456	} else {
1457		btrfs_std_error(root->fs_info, ret, "Slot search failed");
1458		goto out;
1459	}
1460
1461	*dev_extent_len = btrfs_dev_extent_length(leaf, extent);
1462
 
 
 
 
 
1463	ret = btrfs_del_item(trans, root, path);
1464	if (ret) {
1465		btrfs_std_error(root->fs_info, ret,
1466			    "Failed to remove dev extent item");
1467	} else {
1468		set_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags);
1469	}
1470out:
1471	btrfs_free_path(path);
1472	return ret;
1473}
1474
1475static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1476				  struct btrfs_device *device,
1477				  u64 chunk_tree, u64 chunk_objectid,
1478				  u64 chunk_offset, u64 start, u64 num_bytes)
1479{
1480	int ret;
1481	struct btrfs_path *path;
1482	struct btrfs_root *root = device->dev_root;
1483	struct btrfs_dev_extent *extent;
1484	struct extent_buffer *leaf;
1485	struct btrfs_key key;
1486
1487	WARN_ON(!device->in_fs_metadata);
1488	WARN_ON(device->is_tgtdev_for_dev_replace);
1489	path = btrfs_alloc_path();
1490	if (!path)
1491		return -ENOMEM;
1492
1493	key.objectid = device->devid;
1494	key.offset = start;
1495	key.type = BTRFS_DEV_EXTENT_KEY;
1496	ret = btrfs_insert_empty_item(trans, root, path, &key,
1497				      sizeof(*extent));
1498	if (ret)
1499		goto out;
1500
1501	leaf = path->nodes[0];
1502	extent = btrfs_item_ptr(leaf, path->slots[0],
1503				struct btrfs_dev_extent);
1504	btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1505	btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1506	btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1507
1508	write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1509		    btrfs_dev_extent_chunk_tree_uuid(extent), BTRFS_UUID_SIZE);
 
1510
1511	btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1512	btrfs_mark_buffer_dirty(leaf);
1513out:
1514	btrfs_free_path(path);
1515	return ret;
1516}
1517
1518static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
 
1519{
1520	struct extent_map_tree *em_tree;
1521	struct extent_map *em;
1522	struct rb_node *n;
1523	u64 ret = 0;
 
1524
1525	em_tree = &fs_info->mapping_tree.map_tree;
1526	read_lock(&em_tree->lock);
1527	n = rb_last(&em_tree->map);
1528	if (n) {
1529		em = rb_entry(n, struct extent_map, rb_node);
1530		ret = em->start + em->len;
1531	}
1532	read_unlock(&em_tree->lock);
1533
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1534	return ret;
1535}
1536
1537static noinline int find_next_devid(struct btrfs_fs_info *fs_info,
1538				    u64 *devid_ret)
1539{
1540	int ret;
1541	struct btrfs_key key;
1542	struct btrfs_key found_key;
1543	struct btrfs_path *path;
1544
 
 
1545	path = btrfs_alloc_path();
1546	if (!path)
1547		return -ENOMEM;
1548
1549	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1550	key.type = BTRFS_DEV_ITEM_KEY;
1551	key.offset = (u64)-1;
1552
1553	ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0);
1554	if (ret < 0)
1555		goto error;
1556
1557	BUG_ON(ret == 0); /* Corruption */
1558
1559	ret = btrfs_previous_item(fs_info->chunk_root, path,
1560				  BTRFS_DEV_ITEMS_OBJECTID,
1561				  BTRFS_DEV_ITEM_KEY);
1562	if (ret) {
1563		*devid_ret = 1;
1564	} else {
1565		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1566				      path->slots[0]);
1567		*devid_ret = found_key.offset + 1;
1568	}
1569	ret = 0;
1570error:
1571	btrfs_free_path(path);
1572	return ret;
1573}
1574
1575/*
1576 * the device information is stored in the chunk root
1577 * the btrfs_device struct should be fully filled in
1578 */
1579static int btrfs_add_device(struct btrfs_trans_handle *trans,
1580			    struct btrfs_root *root,
1581			    struct btrfs_device *device)
1582{
1583	int ret;
1584	struct btrfs_path *path;
1585	struct btrfs_dev_item *dev_item;
1586	struct extent_buffer *leaf;
1587	struct btrfs_key key;
1588	unsigned long ptr;
1589
1590	root = root->fs_info->chunk_root;
1591
1592	path = btrfs_alloc_path();
1593	if (!path)
1594		return -ENOMEM;
1595
1596	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1597	key.type = BTRFS_DEV_ITEM_KEY;
1598	key.offset = device->devid;
1599
1600	ret = btrfs_insert_empty_item(trans, root, path, &key,
1601				      sizeof(*dev_item));
1602	if (ret)
1603		goto out;
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_generation(leaf, dev_item, 0);
1610	btrfs_set_device_type(leaf, dev_item, device->type);
1611	btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1612	btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1613	btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1614	btrfs_set_device_total_bytes(leaf, dev_item,
1615				     btrfs_device_get_disk_total_bytes(device));
1616	btrfs_set_device_bytes_used(leaf, dev_item,
1617				    btrfs_device_get_bytes_used(device));
1618	btrfs_set_device_group(leaf, dev_item, 0);
1619	btrfs_set_device_seek_speed(leaf, dev_item, 0);
1620	btrfs_set_device_bandwidth(leaf, dev_item, 0);
1621	btrfs_set_device_start_offset(leaf, dev_item, 0);
1622
1623	ptr = btrfs_device_uuid(dev_item);
1624	write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1625	ptr = btrfs_device_fsid(dev_item);
1626	write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1627	btrfs_mark_buffer_dirty(leaf);
1628
1629	ret = 0;
1630out:
1631	btrfs_free_path(path);
1632	return ret;
1633}
1634
1635/*
1636 * Function to update ctime/mtime for a given device path.
1637 * Mainly used for ctime/mtime based probe like libblkid.
1638 */
1639static void update_dev_time(char *path_name)
1640{
1641	struct file *filp;
1642
1643	filp = filp_open(path_name, O_RDWR, 0);
1644	if (IS_ERR(filp))
1645		return;
1646	file_update_time(filp);
1647	filp_close(filp, NULL);
1648}
1649
1650static int btrfs_rm_dev_item(struct btrfs_root *root,
1651			     struct btrfs_device *device)
1652{
1653	int ret;
1654	struct btrfs_path *path;
1655	struct btrfs_key key;
1656	struct btrfs_trans_handle *trans;
1657
1658	root = root->fs_info->chunk_root;
1659
1660	path = btrfs_alloc_path();
1661	if (!path)
1662		return -ENOMEM;
1663
1664	trans = btrfs_start_transaction(root, 0);
1665	if (IS_ERR(trans)) {
1666		btrfs_free_path(path);
1667		return PTR_ERR(trans);
1668	}
1669	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1670	key.type = BTRFS_DEV_ITEM_KEY;
1671	key.offset = device->devid;
 
1672
1673	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1674	if (ret < 0)
1675		goto out;
1676
1677	if (ret > 0) {
1678		ret = -ENOENT;
1679		goto out;
1680	}
1681
1682	ret = btrfs_del_item(trans, root, path);
1683	if (ret)
1684		goto out;
1685out:
1686	btrfs_free_path(path);
 
1687	btrfs_commit_transaction(trans, root);
1688	return ret;
1689}
1690
1691int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1692{
1693	struct btrfs_device *device;
1694	struct btrfs_device *next_device;
1695	struct block_device *bdev;
1696	struct buffer_head *bh = NULL;
1697	struct btrfs_super_block *disk_super;
1698	struct btrfs_fs_devices *cur_devices;
1699	u64 all_avail;
1700	u64 devid;
1701	u64 num_devices;
1702	u8 *dev_uuid;
1703	unsigned seq;
1704	int ret = 0;
1705	bool clear_super = false;
1706
1707	mutex_lock(&uuid_mutex);
1708
1709	do {
1710		seq = read_seqbegin(&root->fs_info->profiles_lock);
1711
1712		all_avail = root->fs_info->avail_data_alloc_bits |
1713			    root->fs_info->avail_system_alloc_bits |
1714			    root->fs_info->avail_metadata_alloc_bits;
1715	} while (read_seqretry(&root->fs_info->profiles_lock, seq));
1716
1717	num_devices = root->fs_info->fs_devices->num_devices;
1718	btrfs_dev_replace_lock(&root->fs_info->dev_replace, 0);
1719	if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
1720		WARN_ON(num_devices < 1);
1721		num_devices--;
1722	}
1723	btrfs_dev_replace_unlock(&root->fs_info->dev_replace, 0);
1724
1725	if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1726		ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
1727		goto out;
1728	}
1729
1730	if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1731		ret = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
1732		goto out;
1733	}
1734
1735	if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
1736	    root->fs_info->fs_devices->rw_devices <= 2) {
1737		ret = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
1738		goto out;
1739	}
1740	if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
1741	    root->fs_info->fs_devices->rw_devices <= 3) {
1742		ret = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
1743		goto out;
1744	}
1745
1746	if (strcmp(device_path, "missing") == 0) {
1747		struct list_head *devices;
1748		struct btrfs_device *tmp;
1749
1750		device = NULL;
1751		devices = &root->fs_info->fs_devices->devices;
1752		/*
1753		 * It is safe to read the devices since the volume_mutex
1754		 * is held.
1755		 */
1756		list_for_each_entry(tmp, devices, dev_list) {
1757			if (tmp->in_fs_metadata &&
1758			    !tmp->is_tgtdev_for_dev_replace &&
1759			    !tmp->bdev) {
1760				device = tmp;
1761				break;
1762			}
1763		}
1764		bdev = NULL;
1765		bh = NULL;
1766		disk_super = NULL;
1767		if (!device) {
1768			ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
 
1769			goto out;
1770		}
1771	} else {
1772		ret = btrfs_get_bdev_and_sb(device_path,
1773					    FMODE_WRITE | FMODE_EXCL,
1774					    root->fs_info->bdev_holder, 0,
1775					    &bdev, &bh);
1776		if (ret)
1777			goto out;
 
 
 
 
 
 
 
 
 
1778		disk_super = (struct btrfs_super_block *)bh->b_data;
1779		devid = btrfs_stack_device_id(&disk_super->dev_item);
1780		dev_uuid = disk_super->dev_item.uuid;
1781		device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1782					   disk_super->fsid);
1783		if (!device) {
1784			ret = -ENOENT;
1785			goto error_brelse;
1786		}
1787	}
1788
1789	if (device->is_tgtdev_for_dev_replace) {
1790		ret = BTRFS_ERROR_DEV_TGT_REPLACE;
1791		goto error_brelse;
1792	}
1793
1794	if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1795		ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
 
 
1796		goto error_brelse;
1797	}
1798
1799	if (device->writeable) {
1800		lock_chunks(root);
1801		list_del_init(&device->dev_alloc_list);
1802		device->fs_devices->rw_devices--;
1803		unlock_chunks(root);
 
1804		clear_super = true;
1805	}
1806
1807	mutex_unlock(&uuid_mutex);
1808	ret = btrfs_shrink_device(device, 0);
1809	mutex_lock(&uuid_mutex);
1810	if (ret)
1811		goto error_undo;
1812
1813	/*
1814	 * TODO: the superblock still includes this device in its num_devices
1815	 * counter although write_all_supers() is not locked out. This
1816	 * could give a filesystem state which requires a degraded mount.
1817	 */
1818	ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1819	if (ret)
1820		goto error_undo;
1821
 
 
 
 
 
1822	device->in_fs_metadata = 0;
1823	btrfs_scrub_cancel_dev(root->fs_info, device);
1824
1825	/*
1826	 * the device list mutex makes sure that we don't change
1827	 * the device list while someone else is writing out all
1828	 * the device supers. Whoever is writing all supers, should
1829	 * lock the device list mutex before getting the number of
1830	 * devices in the super block (super_copy). Conversely,
1831	 * whoever updates the number of devices in the super block
1832	 * (super_copy) should hold the device list mutex.
1833	 */
1834
1835	cur_devices = device->fs_devices;
1836	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1837	list_del_rcu(&device->dev_list);
1838
1839	device->fs_devices->num_devices--;
1840	device->fs_devices->total_devices--;
1841
1842	if (device->missing)
1843		device->fs_devices->missing_devices--;
1844
1845	next_device = list_entry(root->fs_info->fs_devices->devices.next,
1846				 struct btrfs_device, dev_list);
1847	if (device->bdev == root->fs_info->sb->s_bdev)
1848		root->fs_info->sb->s_bdev = next_device->bdev;
1849	if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1850		root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1851
1852	if (device->bdev) {
1853		device->fs_devices->open_devices--;
1854		/* remove sysfs entry */
1855		btrfs_sysfs_rm_device_link(root->fs_info->fs_devices, device);
1856	}
1857
1858	call_rcu(&device->rcu, free_device);
 
1859
1860	num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1861	btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1862	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1863
1864	if (cur_devices->open_devices == 0) {
1865		struct btrfs_fs_devices *fs_devices;
1866		fs_devices = root->fs_info->fs_devices;
1867		while (fs_devices) {
1868			if (fs_devices->seed == cur_devices) {
1869				fs_devices->seed = cur_devices->seed;
1870				break;
1871			}
1872			fs_devices = fs_devices->seed;
1873		}
 
1874		cur_devices->seed = NULL;
 
1875		__btrfs_close_devices(cur_devices);
 
1876		free_fs_devices(cur_devices);
1877	}
1878
1879	root->fs_info->num_tolerated_disk_barrier_failures =
1880		btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1881
1882	/*
1883	 * at this point, the device is zero sized.  We want to
1884	 * remove it from the devices list and zero out the old super
1885	 */
1886	if (clear_super && disk_super) {
1887		u64 bytenr;
1888		int i;
1889
1890		/* make sure this device isn't detected as part of
1891		 * the FS anymore
1892		 */
1893		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1894		set_buffer_dirty(bh);
1895		sync_dirty_buffer(bh);
1896
1897		/* clear the mirror copies of super block on the disk
1898		 * being removed, 0th copy is been taken care above and
1899		 * the below would take of the rest
1900		 */
1901		for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1902			bytenr = btrfs_sb_offset(i);
1903			if (bytenr + BTRFS_SUPER_INFO_SIZE >=
1904					i_size_read(bdev->bd_inode))
1905				break;
1906
1907			brelse(bh);
1908			bh = __bread(bdev, bytenr / 4096,
1909					BTRFS_SUPER_INFO_SIZE);
1910			if (!bh)
1911				continue;
1912
1913			disk_super = (struct btrfs_super_block *)bh->b_data;
1914
1915			if (btrfs_super_bytenr(disk_super) != bytenr ||
1916				btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
1917				continue;
1918			}
1919			memset(&disk_super->magic, 0,
1920						sizeof(disk_super->magic));
1921			set_buffer_dirty(bh);
1922			sync_dirty_buffer(bh);
1923		}
1924	}
1925
1926	ret = 0;
1927
1928	if (bdev) {
1929		/* Notify udev that device has changed */
1930		btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1931
1932		/* Update ctime/mtime for device path for libblkid */
1933		update_dev_time(device_path);
1934	}
1935
1936error_brelse:
1937	brelse(bh);
 
1938	if (bdev)
1939		blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1940out:
1941	mutex_unlock(&uuid_mutex);
1942	return ret;
1943error_undo:
1944	if (device->writeable) {
1945		lock_chunks(root);
1946		list_add(&device->dev_alloc_list,
1947			 &root->fs_info->fs_devices->alloc_list);
1948		device->fs_devices->rw_devices++;
1949		unlock_chunks(root);
 
1950	}
1951	goto error_brelse;
1952}
1953
1954void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_fs_info *fs_info,
1955					struct btrfs_device *srcdev)
1956{
1957	struct btrfs_fs_devices *fs_devices;
1958
1959	WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1960
1961	/*
1962	 * in case of fs with no seed, srcdev->fs_devices will point
1963	 * to fs_devices of fs_info. However when the dev being replaced is
1964	 * a seed dev it will point to the seed's local fs_devices. In short
1965	 * srcdev will have its correct fs_devices in both the cases.
1966	 */
1967	fs_devices = srcdev->fs_devices;
1968
1969	list_del_rcu(&srcdev->dev_list);
1970	list_del_rcu(&srcdev->dev_alloc_list);
1971	fs_devices->num_devices--;
1972	if (srcdev->missing)
1973		fs_devices->missing_devices--;
1974
1975	if (srcdev->writeable) {
1976		fs_devices->rw_devices--;
1977		/* zero out the old super if it is writable */
1978		btrfs_scratch_superblocks(srcdev->bdev, srcdev->name->str);
1979	}
1980
1981	if (srcdev->bdev)
1982		fs_devices->open_devices--;
1983}
1984
1985void btrfs_rm_dev_replace_free_srcdev(struct btrfs_fs_info *fs_info,
1986				      struct btrfs_device *srcdev)
1987{
1988	struct btrfs_fs_devices *fs_devices = srcdev->fs_devices;
1989
1990	call_rcu(&srcdev->rcu, free_device);
1991
1992	/*
1993	 * unless fs_devices is seed fs, num_devices shouldn't go
1994	 * zero
1995	 */
1996	BUG_ON(!fs_devices->num_devices && !fs_devices->seeding);
1997
1998	/* if this is no devs we rather delete the fs_devices */
1999	if (!fs_devices->num_devices) {
2000		struct btrfs_fs_devices *tmp_fs_devices;
2001
2002		tmp_fs_devices = fs_info->fs_devices;
2003		while (tmp_fs_devices) {
2004			if (tmp_fs_devices->seed == fs_devices) {
2005				tmp_fs_devices->seed = fs_devices->seed;
2006				break;
2007			}
2008			tmp_fs_devices = tmp_fs_devices->seed;
2009		}
2010		fs_devices->seed = NULL;
2011		__btrfs_close_devices(fs_devices);
2012		free_fs_devices(fs_devices);
2013	}
2014}
2015
2016void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
2017				      struct btrfs_device *tgtdev)
2018{
2019	struct btrfs_device *next_device;
2020
2021	mutex_lock(&uuid_mutex);
2022	WARN_ON(!tgtdev);
2023	mutex_lock(&fs_info->fs_devices->device_list_mutex);
2024
2025	btrfs_sysfs_rm_device_link(fs_info->fs_devices, tgtdev);
2026
2027	if (tgtdev->bdev) {
2028		btrfs_scratch_superblocks(tgtdev->bdev, tgtdev->name->str);
2029		fs_info->fs_devices->open_devices--;
2030	}
2031	fs_info->fs_devices->num_devices--;
2032
2033	next_device = list_entry(fs_info->fs_devices->devices.next,
2034				 struct btrfs_device, dev_list);
2035	if (tgtdev->bdev == fs_info->sb->s_bdev)
2036		fs_info->sb->s_bdev = next_device->bdev;
2037	if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
2038		fs_info->fs_devices->latest_bdev = next_device->bdev;
2039	list_del_rcu(&tgtdev->dev_list);
2040
2041	call_rcu(&tgtdev->rcu, free_device);
2042
2043	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
2044	mutex_unlock(&uuid_mutex);
2045}
2046
2047static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
2048				     struct btrfs_device **device)
2049{
2050	int ret = 0;
2051	struct btrfs_super_block *disk_super;
2052	u64 devid;
2053	u8 *dev_uuid;
2054	struct block_device *bdev;
2055	struct buffer_head *bh;
2056
2057	*device = NULL;
2058	ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
2059				    root->fs_info->bdev_holder, 0, &bdev, &bh);
2060	if (ret)
2061		return ret;
2062	disk_super = (struct btrfs_super_block *)bh->b_data;
2063	devid = btrfs_stack_device_id(&disk_super->dev_item);
2064	dev_uuid = disk_super->dev_item.uuid;
2065	*device = btrfs_find_device(root->fs_info, devid, dev_uuid,
2066				    disk_super->fsid);
2067	brelse(bh);
2068	if (!*device)
2069		ret = -ENOENT;
2070	blkdev_put(bdev, FMODE_READ);
2071	return ret;
2072}
2073
2074int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
2075					 char *device_path,
2076					 struct btrfs_device **device)
2077{
2078	*device = NULL;
2079	if (strcmp(device_path, "missing") == 0) {
2080		struct list_head *devices;
2081		struct btrfs_device *tmp;
2082
2083		devices = &root->fs_info->fs_devices->devices;
2084		/*
2085		 * It is safe to read the devices since the volume_mutex
2086		 * is held by the caller.
2087		 */
2088		list_for_each_entry(tmp, devices, dev_list) {
2089			if (tmp->in_fs_metadata && !tmp->bdev) {
2090				*device = tmp;
2091				break;
2092			}
2093		}
2094
2095		if (!*device)
2096			return BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
2097
2098		return 0;
2099	} else {
2100		return btrfs_find_device_by_path(root, device_path, device);
2101	}
2102}
2103
2104/*
2105 * does all the dirty work required for changing file system's UUID.
2106 */
2107static int btrfs_prepare_sprout(struct btrfs_root *root)
2108{
2109	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2110	struct btrfs_fs_devices *old_devices;
2111	struct btrfs_fs_devices *seed_devices;
2112	struct btrfs_super_block *disk_super = root->fs_info->super_copy;
2113	struct btrfs_device *device;
2114	u64 super_flags;
2115
2116	BUG_ON(!mutex_is_locked(&uuid_mutex));
2117	if (!fs_devices->seeding)
2118		return -EINVAL;
2119
2120	seed_devices = __alloc_fs_devices();
2121	if (IS_ERR(seed_devices))
2122		return PTR_ERR(seed_devices);
2123
2124	old_devices = clone_fs_devices(fs_devices);
2125	if (IS_ERR(old_devices)) {
2126		kfree(seed_devices);
2127		return PTR_ERR(old_devices);
2128	}
2129
2130	list_add(&old_devices->list, &fs_uuids);
2131
2132	memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
2133	seed_devices->opened = 1;
2134	INIT_LIST_HEAD(&seed_devices->devices);
2135	INIT_LIST_HEAD(&seed_devices->alloc_list);
2136	mutex_init(&seed_devices->device_list_mutex);
2137
2138	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2139	list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
2140			      synchronize_rcu);
2141	list_for_each_entry(device, &seed_devices->devices, dev_list)
2142		device->fs_devices = seed_devices;
2143
2144	lock_chunks(root);
2145	list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
2146	unlock_chunks(root);
 
 
2147
2148	fs_devices->seeding = 0;
2149	fs_devices->num_devices = 0;
2150	fs_devices->open_devices = 0;
2151	fs_devices->missing_devices = 0;
2152	fs_devices->rotating = 0;
2153	fs_devices->seed = seed_devices;
2154
2155	generate_random_uuid(fs_devices->fsid);
2156	memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
2157	memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
2158	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2159
2160	super_flags = btrfs_super_flags(disk_super) &
2161		      ~BTRFS_SUPER_FLAG_SEEDING;
2162	btrfs_set_super_flags(disk_super, super_flags);
2163
2164	return 0;
2165}
2166
2167/*
2168 * strore the expected generation for seed devices in device items.
2169 */
2170static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
2171			       struct btrfs_root *root)
2172{
2173	struct btrfs_path *path;
2174	struct extent_buffer *leaf;
2175	struct btrfs_dev_item *dev_item;
2176	struct btrfs_device *device;
2177	struct btrfs_key key;
2178	u8 fs_uuid[BTRFS_UUID_SIZE];
2179	u8 dev_uuid[BTRFS_UUID_SIZE];
2180	u64 devid;
2181	int ret;
2182
2183	path = btrfs_alloc_path();
2184	if (!path)
2185		return -ENOMEM;
2186
2187	root = root->fs_info->chunk_root;
2188	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2189	key.offset = 0;
2190	key.type = BTRFS_DEV_ITEM_KEY;
2191
2192	while (1) {
2193		ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2194		if (ret < 0)
2195			goto error;
2196
2197		leaf = path->nodes[0];
2198next_slot:
2199		if (path->slots[0] >= btrfs_header_nritems(leaf)) {
2200			ret = btrfs_next_leaf(root, path);
2201			if (ret > 0)
2202				break;
2203			if (ret < 0)
2204				goto error;
2205			leaf = path->nodes[0];
2206			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2207			btrfs_release_path(path);
2208			continue;
2209		}
2210
2211		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2212		if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
2213		    key.type != BTRFS_DEV_ITEM_KEY)
2214			break;
2215
2216		dev_item = btrfs_item_ptr(leaf, path->slots[0],
2217					  struct btrfs_dev_item);
2218		devid = btrfs_device_id(leaf, dev_item);
2219		read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
 
2220				   BTRFS_UUID_SIZE);
2221		read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
 
2222				   BTRFS_UUID_SIZE);
2223		device = btrfs_find_device(root->fs_info, devid, dev_uuid,
2224					   fs_uuid);
2225		BUG_ON(!device); /* Logic error */
2226
2227		if (device->fs_devices->seeding) {
2228			btrfs_set_device_generation(leaf, dev_item,
2229						    device->generation);
2230			btrfs_mark_buffer_dirty(leaf);
2231		}
2232
2233		path->slots[0]++;
2234		goto next_slot;
2235	}
2236	ret = 0;
2237error:
2238	btrfs_free_path(path);
2239	return ret;
2240}
2241
2242int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
2243{
2244	struct request_queue *q;
2245	struct btrfs_trans_handle *trans;
2246	struct btrfs_device *device;
2247	struct block_device *bdev;
2248	struct list_head *devices;
2249	struct super_block *sb = root->fs_info->sb;
2250	struct rcu_string *name;
2251	u64 tmp;
2252	int seeding_dev = 0;
2253	int ret = 0;
2254
2255	if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
2256		return -EROFS;
2257
2258	bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2259				  root->fs_info->bdev_holder);
2260	if (IS_ERR(bdev))
2261		return PTR_ERR(bdev);
2262
2263	if (root->fs_info->fs_devices->seeding) {
2264		seeding_dev = 1;
2265		down_write(&sb->s_umount);
2266		mutex_lock(&uuid_mutex);
2267	}
2268
2269	filemap_write_and_wait(bdev->bd_inode->i_mapping);
2270
2271	devices = &root->fs_info->fs_devices->devices;
2272
2273	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
 
 
2274	list_for_each_entry(device, devices, dev_list) {
2275		if (device->bdev == bdev) {
2276			ret = -EEXIST;
2277			mutex_unlock(
2278				&root->fs_info->fs_devices->device_list_mutex);
2279			goto error;
2280		}
2281	}
2282	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2283
2284	device = btrfs_alloc_device(root->fs_info, NULL, NULL);
2285	if (IS_ERR(device)) {
2286		/* we can safely leave the fs_devices entry around */
2287		ret = PTR_ERR(device);
2288		goto error;
2289	}
2290
2291	name = rcu_string_strdup(device_path, GFP_KERNEL);
2292	if (!name) {
2293		kfree(device);
2294		ret = -ENOMEM;
2295		goto error;
2296	}
2297	rcu_assign_pointer(device->name, name);
2298
 
 
 
 
 
 
 
2299	trans = btrfs_start_transaction(root, 0);
2300	if (IS_ERR(trans)) {
2301		rcu_string_free(device->name);
2302		kfree(device);
2303		ret = PTR_ERR(trans);
2304		goto error;
2305	}
2306
 
 
2307	q = bdev_get_queue(bdev);
2308	if (blk_queue_discard(q))
2309		device->can_discard = 1;
2310	device->writeable = 1;
 
 
 
2311	device->generation = trans->transid;
2312	device->io_width = root->sectorsize;
2313	device->io_align = root->sectorsize;
2314	device->sector_size = root->sectorsize;
2315	device->total_bytes = i_size_read(bdev->bd_inode);
2316	device->disk_total_bytes = device->total_bytes;
2317	device->commit_total_bytes = device->total_bytes;
2318	device->dev_root = root->fs_info->dev_root;
2319	device->bdev = bdev;
2320	device->in_fs_metadata = 1;
2321	device->is_tgtdev_for_dev_replace = 0;
2322	device->mode = FMODE_EXCL;
2323	device->dev_stats_valid = 1;
2324	set_blocksize(device->bdev, 4096);
2325
2326	if (seeding_dev) {
2327		sb->s_flags &= ~MS_RDONLY;
2328		ret = btrfs_prepare_sprout(root);
2329		BUG_ON(ret); /* -ENOMEM */
2330	}
2331
2332	device->fs_devices = root->fs_info->fs_devices;
2333
 
 
 
 
2334	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2335	lock_chunks(root);
2336	list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2337	list_add(&device->dev_alloc_list,
2338		 &root->fs_info->fs_devices->alloc_list);
2339	root->fs_info->fs_devices->num_devices++;
2340	root->fs_info->fs_devices->open_devices++;
2341	root->fs_info->fs_devices->rw_devices++;
2342	root->fs_info->fs_devices->total_devices++;
 
2343	root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2344
2345	spin_lock(&root->fs_info->free_chunk_lock);
2346	root->fs_info->free_chunk_space += device->total_bytes;
2347	spin_unlock(&root->fs_info->free_chunk_lock);
2348
2349	if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2350		root->fs_info->fs_devices->rotating = 1;
2351
2352	tmp = btrfs_super_total_bytes(root->fs_info->super_copy);
2353	btrfs_set_super_total_bytes(root->fs_info->super_copy,
2354				    tmp + device->total_bytes);
2355
2356	tmp = btrfs_super_num_devices(root->fs_info->super_copy);
2357	btrfs_set_super_num_devices(root->fs_info->super_copy,
2358				    tmp + 1);
2359
2360	/* add sysfs device entry */
2361	btrfs_sysfs_add_device_link(root->fs_info->fs_devices, device);
2362
2363	/*
2364	 * we've got more storage, clear any full flags on the space
2365	 * infos
2366	 */
2367	btrfs_clear_space_info_full(root->fs_info);
2368
2369	unlock_chunks(root);
2370	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2371
2372	if (seeding_dev) {
2373		lock_chunks(root);
2374		ret = init_first_rw_device(trans, root, device);
2375		unlock_chunks(root);
2376		if (ret) {
2377			btrfs_abort_transaction(trans, root, ret);
2378			goto error_trans;
2379		}
2380	}
2381
2382	ret = btrfs_add_device(trans, root, device);
2383	if (ret) {
2384		btrfs_abort_transaction(trans, root, ret);
2385		goto error_trans;
2386	}
2387
2388	if (seeding_dev) {
2389		char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
2390
2391		ret = btrfs_finish_sprout(trans, root);
2392		if (ret) {
2393			btrfs_abort_transaction(trans, root, ret);
 
 
 
2394			goto error_trans;
2395		}
2396
2397		/* Sprouting would change fsid of the mounted root,
2398		 * so rename the fsid on the sysfs
2399		 */
2400		snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU",
2401						root->fs_info->fsid);
2402		if (kobject_rename(&root->fs_info->fs_devices->fsid_kobj,
2403								fsid_buf))
2404			btrfs_warn(root->fs_info,
2405				"sysfs: failed to create fsid for sprout");
2406	}
2407
2408	root->fs_info->num_tolerated_disk_barrier_failures =
2409		btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
 
 
 
 
 
2410	ret = btrfs_commit_transaction(trans, root);
2411
2412	if (seeding_dev) {
2413		mutex_unlock(&uuid_mutex);
2414		up_write(&sb->s_umount);
2415
2416		if (ret) /* transaction commit */
2417			return ret;
2418
2419		ret = btrfs_relocate_sys_chunks(root);
2420		if (ret < 0)
2421			btrfs_std_error(root->fs_info, ret,
2422				    "Failed to relocate sys chunks after "
2423				    "device initialization. This can be fixed "
2424				    "using the \"btrfs balance\" command.");
2425		trans = btrfs_attach_transaction(root);
2426		if (IS_ERR(trans)) {
2427			if (PTR_ERR(trans) == -ENOENT)
2428				return 0;
2429			return PTR_ERR(trans);
2430		}
2431		ret = btrfs_commit_transaction(trans, root);
2432	}
2433
2434	/* Update ctime/mtime for libblkid */
2435	update_dev_time(device_path);
2436	return ret;
2437
2438error_trans:
 
 
2439	btrfs_end_transaction(trans, root);
2440	rcu_string_free(device->name);
2441	btrfs_sysfs_rm_device_link(root->fs_info->fs_devices, device);
2442	kfree(device);
2443error:
2444	blkdev_put(bdev, FMODE_EXCL);
2445	if (seeding_dev) {
2446		mutex_unlock(&uuid_mutex);
2447		up_write(&sb->s_umount);
2448	}
2449	return ret;
2450}
2451
2452int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2453				  struct btrfs_device *srcdev,
2454				  struct btrfs_device **device_out)
2455{
2456	struct request_queue *q;
2457	struct btrfs_device *device;
2458	struct block_device *bdev;
2459	struct btrfs_fs_info *fs_info = root->fs_info;
2460	struct list_head *devices;
2461	struct rcu_string *name;
2462	u64 devid = BTRFS_DEV_REPLACE_DEVID;
2463	int ret = 0;
2464
2465	*device_out = NULL;
2466	if (fs_info->fs_devices->seeding) {
2467		btrfs_err(fs_info, "the filesystem is a seed filesystem!");
2468		return -EINVAL;
2469	}
2470
2471	bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2472				  fs_info->bdev_holder);
2473	if (IS_ERR(bdev)) {
2474		btrfs_err(fs_info, "target device %s is invalid!", device_path);
2475		return PTR_ERR(bdev);
2476	}
2477
2478	filemap_write_and_wait(bdev->bd_inode->i_mapping);
2479
2480	devices = &fs_info->fs_devices->devices;
2481	list_for_each_entry(device, devices, dev_list) {
2482		if (device->bdev == bdev) {
2483			btrfs_err(fs_info, "target device is in the filesystem!");
2484			ret = -EEXIST;
2485			goto error;
2486		}
2487	}
2488
2489
2490	if (i_size_read(bdev->bd_inode) <
2491	    btrfs_device_get_total_bytes(srcdev)) {
2492		btrfs_err(fs_info, "target device is smaller than source device!");
2493		ret = -EINVAL;
2494		goto error;
2495	}
2496
2497
2498	device = btrfs_alloc_device(NULL, &devid, NULL);
2499	if (IS_ERR(device)) {
2500		ret = PTR_ERR(device);
2501		goto error;
2502	}
2503
2504	name = rcu_string_strdup(device_path, GFP_NOFS);
2505	if (!name) {
2506		kfree(device);
2507		ret = -ENOMEM;
2508		goto error;
2509	}
2510	rcu_assign_pointer(device->name, name);
2511
2512	q = bdev_get_queue(bdev);
2513	if (blk_queue_discard(q))
2514		device->can_discard = 1;
2515	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2516	device->writeable = 1;
2517	device->generation = 0;
2518	device->io_width = root->sectorsize;
2519	device->io_align = root->sectorsize;
2520	device->sector_size = root->sectorsize;
2521	device->total_bytes = btrfs_device_get_total_bytes(srcdev);
2522	device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev);
2523	device->bytes_used = btrfs_device_get_bytes_used(srcdev);
2524	ASSERT(list_empty(&srcdev->resized_list));
2525	device->commit_total_bytes = srcdev->commit_total_bytes;
2526	device->commit_bytes_used = device->bytes_used;
2527	device->dev_root = fs_info->dev_root;
2528	device->bdev = bdev;
2529	device->in_fs_metadata = 1;
2530	device->is_tgtdev_for_dev_replace = 1;
2531	device->mode = FMODE_EXCL;
2532	device->dev_stats_valid = 1;
2533	set_blocksize(device->bdev, 4096);
2534	device->fs_devices = fs_info->fs_devices;
2535	list_add(&device->dev_list, &fs_info->fs_devices->devices);
2536	fs_info->fs_devices->num_devices++;
2537	fs_info->fs_devices->open_devices++;
2538	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2539
2540	*device_out = device;
2541	return ret;
2542
2543error:
2544	blkdev_put(bdev, FMODE_EXCL);
2545	return ret;
2546}
2547
2548void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2549					      struct btrfs_device *tgtdev)
2550{
2551	WARN_ON(fs_info->fs_devices->rw_devices == 0);
2552	tgtdev->io_width = fs_info->dev_root->sectorsize;
2553	tgtdev->io_align = fs_info->dev_root->sectorsize;
2554	tgtdev->sector_size = fs_info->dev_root->sectorsize;
2555	tgtdev->dev_root = fs_info->dev_root;
2556	tgtdev->in_fs_metadata = 1;
2557}
2558
2559static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2560					struct btrfs_device *device)
2561{
2562	int ret;
2563	struct btrfs_path *path;
2564	struct btrfs_root *root;
2565	struct btrfs_dev_item *dev_item;
2566	struct extent_buffer *leaf;
2567	struct btrfs_key key;
2568
2569	root = device->dev_root->fs_info->chunk_root;
2570
2571	path = btrfs_alloc_path();
2572	if (!path)
2573		return -ENOMEM;
2574
2575	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2576	key.type = BTRFS_DEV_ITEM_KEY;
2577	key.offset = device->devid;
2578
2579	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2580	if (ret < 0)
2581		goto out;
2582
2583	if (ret > 0) {
2584		ret = -ENOENT;
2585		goto out;
2586	}
2587
2588	leaf = path->nodes[0];
2589	dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2590
2591	btrfs_set_device_id(leaf, dev_item, device->devid);
2592	btrfs_set_device_type(leaf, dev_item, device->type);
2593	btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2594	btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2595	btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2596	btrfs_set_device_total_bytes(leaf, dev_item,
2597				     btrfs_device_get_disk_total_bytes(device));
2598	btrfs_set_device_bytes_used(leaf, dev_item,
2599				    btrfs_device_get_bytes_used(device));
2600	btrfs_mark_buffer_dirty(leaf);
2601
2602out:
2603	btrfs_free_path(path);
2604	return ret;
2605}
2606
2607int btrfs_grow_device(struct btrfs_trans_handle *trans,
2608		      struct btrfs_device *device, u64 new_size)
2609{
2610	struct btrfs_super_block *super_copy =
2611		device->dev_root->fs_info->super_copy;
2612	struct btrfs_fs_devices *fs_devices;
2613	u64 old_total;
2614	u64 diff;
2615
2616	if (!device->writeable)
2617		return -EACCES;
2618
2619	lock_chunks(device->dev_root);
2620	old_total = btrfs_super_total_bytes(super_copy);
2621	diff = new_size - device->total_bytes;
2622
2623	if (new_size <= device->total_bytes ||
2624	    device->is_tgtdev_for_dev_replace) {
2625		unlock_chunks(device->dev_root);
2626		return -EINVAL;
2627	}
2628
2629	fs_devices = device->dev_root->fs_info->fs_devices;
2630
2631	btrfs_set_super_total_bytes(super_copy, old_total + diff);
2632	device->fs_devices->total_rw_bytes += diff;
2633
2634	btrfs_device_set_total_bytes(device, new_size);
2635	btrfs_device_set_disk_total_bytes(device, new_size);
2636	btrfs_clear_space_info_full(device->dev_root->fs_info);
2637	if (list_empty(&device->resized_list))
2638		list_add_tail(&device->resized_list,
2639			      &fs_devices->resized_devices);
2640	unlock_chunks(device->dev_root);
2641
2642	return btrfs_update_device(trans, device);
2643}
2644
 
 
 
 
 
 
 
 
 
 
2645static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2646			    struct btrfs_root *root, u64 chunk_objectid,
 
2647			    u64 chunk_offset)
2648{
2649	int ret;
2650	struct btrfs_path *path;
2651	struct btrfs_key key;
2652
2653	root = root->fs_info->chunk_root;
2654	path = btrfs_alloc_path();
2655	if (!path)
2656		return -ENOMEM;
2657
2658	key.objectid = chunk_objectid;
2659	key.offset = chunk_offset;
2660	key.type = BTRFS_CHUNK_ITEM_KEY;
2661
2662	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2663	if (ret < 0)
2664		goto out;
2665	else if (ret > 0) { /* Logic error or corruption */
2666		btrfs_std_error(root->fs_info, -ENOENT,
2667			    "Failed lookup while freeing chunk.");
2668		ret = -ENOENT;
2669		goto out;
2670	}
2671
2672	ret = btrfs_del_item(trans, root, path);
2673	if (ret < 0)
2674		btrfs_std_error(root->fs_info, ret,
2675			    "Failed to delete chunk item.");
2676out:
2677	btrfs_free_path(path);
2678	return ret;
2679}
2680
2681static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2682			chunk_offset)
2683{
2684	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2685	struct btrfs_disk_key *disk_key;
2686	struct btrfs_chunk *chunk;
2687	u8 *ptr;
2688	int ret = 0;
2689	u32 num_stripes;
2690	u32 array_size;
2691	u32 len = 0;
2692	u32 cur;
2693	struct btrfs_key key;
2694
2695	lock_chunks(root);
2696	array_size = btrfs_super_sys_array_size(super_copy);
2697
2698	ptr = super_copy->sys_chunk_array;
2699	cur = 0;
2700
2701	while (cur < array_size) {
2702		disk_key = (struct btrfs_disk_key *)ptr;
2703		btrfs_disk_key_to_cpu(&key, disk_key);
2704
2705		len = sizeof(*disk_key);
2706
2707		if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2708			chunk = (struct btrfs_chunk *)(ptr + len);
2709			num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2710			len += btrfs_chunk_item_size(num_stripes);
2711		} else {
2712			ret = -EIO;
2713			break;
2714		}
2715		if (key.objectid == chunk_objectid &&
2716		    key.offset == chunk_offset) {
2717			memmove(ptr, ptr + len, array_size - (cur + len));
2718			array_size -= len;
2719			btrfs_set_super_sys_array_size(super_copy, array_size);
2720		} else {
2721			ptr += len;
2722			cur += len;
2723		}
2724	}
2725	unlock_chunks(root);
2726	return ret;
2727}
2728
2729int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
2730		       struct btrfs_root *root, u64 chunk_offset)
 
2731{
2732	struct extent_map_tree *em_tree;
 
 
2733	struct extent_map *em;
2734	struct btrfs_root *extent_root = root->fs_info->extent_root;
2735	struct map_lookup *map;
2736	u64 dev_extent_len = 0;
2737	u64 chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2738	int i, ret = 0;
2739
2740	/* Just in case */
2741	root = root->fs_info->chunk_root;
 
2742	em_tree = &root->fs_info->mapping_tree.map_tree;
2743
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2744	read_lock(&em_tree->lock);
2745	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2746	read_unlock(&em_tree->lock);
2747
2748	if (!em || em->start > chunk_offset ||
2749	    em->start + em->len < chunk_offset) {
2750		/*
2751		 * This is a logic error, but we don't want to just rely on the
2752		 * user having built with ASSERT enabled, so if ASSERT doesn't
2753		 * do anything we still error out.
2754		 */
2755		ASSERT(0);
2756		if (em)
2757			free_extent_map(em);
2758		return -EINVAL;
2759	}
2760	map = em->map_lookup;
2761	lock_chunks(root->fs_info->chunk_root);
2762	check_system_chunk(trans, extent_root, map->type);
2763	unlock_chunks(root->fs_info->chunk_root);
2764
2765	for (i = 0; i < map->num_stripes; i++) {
2766		struct btrfs_device *device = map->stripes[i].dev;
2767		ret = btrfs_free_dev_extent(trans, device,
2768					    map->stripes[i].physical,
2769					    &dev_extent_len);
2770		if (ret) {
2771			btrfs_abort_transaction(trans, root, ret);
2772			goto out;
2773		}
2774
2775		if (device->bytes_used > 0) {
2776			lock_chunks(root);
2777			btrfs_device_set_bytes_used(device,
2778					device->bytes_used - dev_extent_len);
2779			spin_lock(&root->fs_info->free_chunk_lock);
2780			root->fs_info->free_chunk_space += dev_extent_len;
2781			spin_unlock(&root->fs_info->free_chunk_lock);
2782			btrfs_clear_space_info_full(root->fs_info);
2783			unlock_chunks(root);
2784		}
2785
2786		if (map->stripes[i].dev) {
2787			ret = btrfs_update_device(trans, map->stripes[i].dev);
2788			if (ret) {
2789				btrfs_abort_transaction(trans, root, ret);
2790				goto out;
2791			}
2792		}
2793	}
2794	ret = btrfs_free_chunk(trans, root, chunk_objectid, chunk_offset);
2795	if (ret) {
2796		btrfs_abort_transaction(trans, root, ret);
2797		goto out;
2798	}
2799
2800	trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2801
2802	if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2803		ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2804		if (ret) {
2805			btrfs_abort_transaction(trans, root, ret);
2806			goto out;
2807		}
2808	}
2809
2810	ret = btrfs_remove_block_group(trans, extent_root, chunk_offset, em);
2811	if (ret) {
2812		btrfs_abort_transaction(trans, extent_root, ret);
2813		goto out;
2814	}
2815
2816out:
2817	/* once for us */
2818	free_extent_map(em);
2819	return ret;
2820}
2821
2822static int btrfs_relocate_chunk(struct btrfs_root *root, u64 chunk_offset)
2823{
2824	struct btrfs_root *extent_root;
2825	struct btrfs_trans_handle *trans;
2826	int ret;
2827
2828	root = root->fs_info->chunk_root;
2829	extent_root = root->fs_info->extent_root;
2830
2831	/*
2832	 * Prevent races with automatic removal of unused block groups.
2833	 * After we relocate and before we remove the chunk with offset
2834	 * chunk_offset, automatic removal of the block group can kick in,
2835	 * resulting in a failure when calling btrfs_remove_chunk() below.
2836	 *
2837	 * Make sure to acquire this mutex before doing a tree search (dev
2838	 * or chunk trees) to find chunks. Otherwise the cleaner kthread might
2839	 * call btrfs_remove_chunk() (through btrfs_delete_unused_bgs()) after
2840	 * we release the path used to search the chunk/dev tree and before
2841	 * the current task acquires this mutex and calls us.
2842	 */
2843	ASSERT(mutex_is_locked(&root->fs_info->delete_unused_bgs_mutex));
2844
2845	ret = btrfs_can_relocate(extent_root, chunk_offset);
2846	if (ret)
2847		return -ENOSPC;
2848
2849	/* step one, relocate all the extents inside this chunk */
2850	btrfs_scrub_pause(root);
2851	ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2852	btrfs_scrub_continue(root);
2853	if (ret)
2854		return ret;
2855
2856	trans = btrfs_start_trans_remove_block_group(root->fs_info,
2857						     chunk_offset);
2858	if (IS_ERR(trans)) {
2859		ret = PTR_ERR(trans);
2860		btrfs_std_error(root->fs_info, ret, NULL);
2861		return ret;
2862	}
2863
2864	/*
2865	 * step two, delete the device extents and the
2866	 * chunk tree entries
2867	 */
2868	ret = btrfs_remove_chunk(trans, root, chunk_offset);
2869	btrfs_end_transaction(trans, root);
2870	return ret;
2871}
2872
2873static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2874{
2875	struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2876	struct btrfs_path *path;
2877	struct extent_buffer *leaf;
2878	struct btrfs_chunk *chunk;
2879	struct btrfs_key key;
2880	struct btrfs_key found_key;
 
2881	u64 chunk_type;
2882	bool retried = false;
2883	int failed = 0;
2884	int ret;
2885
2886	path = btrfs_alloc_path();
2887	if (!path)
2888		return -ENOMEM;
2889
2890again:
2891	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2892	key.offset = (u64)-1;
2893	key.type = BTRFS_CHUNK_ITEM_KEY;
2894
2895	while (1) {
2896		mutex_lock(&root->fs_info->delete_unused_bgs_mutex);
2897		ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2898		if (ret < 0) {
2899			mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
2900			goto error;
2901		}
2902		BUG_ON(ret == 0); /* Corruption */
2903
2904		ret = btrfs_previous_item(chunk_root, path, key.objectid,
2905					  key.type);
2906		if (ret)
2907			mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
2908		if (ret < 0)
2909			goto error;
2910		if (ret > 0)
2911			break;
2912
2913		leaf = path->nodes[0];
2914		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2915
2916		chunk = btrfs_item_ptr(leaf, path->slots[0],
2917				       struct btrfs_chunk);
2918		chunk_type = btrfs_chunk_type(leaf, chunk);
2919		btrfs_release_path(path);
2920
2921		if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2922			ret = btrfs_relocate_chunk(chunk_root,
 
2923						   found_key.offset);
2924			if (ret == -ENOSPC)
2925				failed++;
2926			else
2927				BUG_ON(ret);
2928		}
2929		mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
2930
2931		if (found_key.offset == 0)
2932			break;
2933		key.offset = found_key.offset - 1;
2934	}
2935	ret = 0;
2936	if (failed && !retried) {
2937		failed = 0;
2938		retried = true;
2939		goto again;
2940	} else if (WARN_ON(failed && retried)) {
 
2941		ret = -ENOSPC;
2942	}
2943error:
2944	btrfs_free_path(path);
2945	return ret;
2946}
2947
2948static int insert_balance_item(struct btrfs_root *root,
2949			       struct btrfs_balance_control *bctl)
2950{
2951	struct btrfs_trans_handle *trans;
2952	struct btrfs_balance_item *item;
2953	struct btrfs_disk_balance_args disk_bargs;
2954	struct btrfs_path *path;
2955	struct extent_buffer *leaf;
2956	struct btrfs_key key;
2957	int ret, err;
2958
2959	path = btrfs_alloc_path();
2960	if (!path)
2961		return -ENOMEM;
2962
2963	trans = btrfs_start_transaction(root, 0);
2964	if (IS_ERR(trans)) {
2965		btrfs_free_path(path);
2966		return PTR_ERR(trans);
2967	}
2968
2969	key.objectid = BTRFS_BALANCE_OBJECTID;
2970	key.type = BTRFS_TEMPORARY_ITEM_KEY;
2971	key.offset = 0;
2972
2973	ret = btrfs_insert_empty_item(trans, root, path, &key,
2974				      sizeof(*item));
2975	if (ret)
2976		goto out;
2977
2978	leaf = path->nodes[0];
2979	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2980
2981	memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2982
2983	btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2984	btrfs_set_balance_data(leaf, item, &disk_bargs);
2985	btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2986	btrfs_set_balance_meta(leaf, item, &disk_bargs);
2987	btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2988	btrfs_set_balance_sys(leaf, item, &disk_bargs);
2989
2990	btrfs_set_balance_flags(leaf, item, bctl->flags);
2991
2992	btrfs_mark_buffer_dirty(leaf);
2993out:
2994	btrfs_free_path(path);
2995	err = btrfs_commit_transaction(trans, root);
2996	if (err && !ret)
2997		ret = err;
2998	return ret;
2999}
3000
3001static int del_balance_item(struct btrfs_root *root)
3002{
3003	struct btrfs_trans_handle *trans;
3004	struct btrfs_path *path;
3005	struct btrfs_key key;
3006	int ret, err;
3007
3008	path = btrfs_alloc_path();
3009	if (!path)
3010		return -ENOMEM;
3011
3012	trans = btrfs_start_transaction(root, 0);
3013	if (IS_ERR(trans)) {
3014		btrfs_free_path(path);
3015		return PTR_ERR(trans);
3016	}
3017
3018	key.objectid = BTRFS_BALANCE_OBJECTID;
3019	key.type = BTRFS_TEMPORARY_ITEM_KEY;
3020	key.offset = 0;
3021
3022	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3023	if (ret < 0)
3024		goto out;
3025	if (ret > 0) {
3026		ret = -ENOENT;
3027		goto out;
3028	}
3029
3030	ret = btrfs_del_item(trans, root, path);
3031out:
3032	btrfs_free_path(path);
3033	err = btrfs_commit_transaction(trans, root);
3034	if (err && !ret)
3035		ret = err;
3036	return ret;
3037}
3038
3039/*
3040 * This is a heuristic used to reduce the number of chunks balanced on
3041 * resume after balance was interrupted.
3042 */
3043static void update_balance_args(struct btrfs_balance_control *bctl)
3044{
3045	/*
3046	 * Turn on soft mode for chunk types that were being converted.
3047	 */
3048	if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
3049		bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
3050	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
3051		bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
3052	if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
3053		bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
3054
3055	/*
3056	 * Turn on usage filter if is not already used.  The idea is
3057	 * that chunks that we have already balanced should be
3058	 * reasonably full.  Don't do it for chunks that are being
3059	 * converted - that will keep us from relocating unconverted
3060	 * (albeit full) chunks.
3061	 */
3062	if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
3063	    !(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
3064	    !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
3065		bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
3066		bctl->data.usage = 90;
3067	}
3068	if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
3069	    !(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
3070	    !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
3071		bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
3072		bctl->sys.usage = 90;
3073	}
3074	if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
3075	    !(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
3076	    !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
3077		bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
3078		bctl->meta.usage = 90;
3079	}
3080}
3081
3082/*
3083 * Should be called with both balance and volume mutexes held to
3084 * serialize other volume operations (add_dev/rm_dev/resize) with
3085 * restriper.  Same goes for unset_balance_control.
3086 */
3087static void set_balance_control(struct btrfs_balance_control *bctl)
3088{
3089	struct btrfs_fs_info *fs_info = bctl->fs_info;
3090
3091	BUG_ON(fs_info->balance_ctl);
3092
3093	spin_lock(&fs_info->balance_lock);
3094	fs_info->balance_ctl = bctl;
3095	spin_unlock(&fs_info->balance_lock);
3096}
3097
3098static void unset_balance_control(struct btrfs_fs_info *fs_info)
3099{
3100	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3101
3102	BUG_ON(!fs_info->balance_ctl);
3103
3104	spin_lock(&fs_info->balance_lock);
3105	fs_info->balance_ctl = NULL;
3106	spin_unlock(&fs_info->balance_lock);
3107
3108	kfree(bctl);
3109}
3110
3111/*
3112 * Balance filters.  Return 1 if chunk should be filtered out
3113 * (should not be balanced).
3114 */
3115static int chunk_profiles_filter(u64 chunk_type,
3116				 struct btrfs_balance_args *bargs)
3117{
3118	chunk_type = chunk_to_extended(chunk_type) &
3119				BTRFS_EXTENDED_PROFILE_MASK;
3120
3121	if (bargs->profiles & chunk_type)
3122		return 0;
3123
3124	return 1;
3125}
3126
3127static int chunk_usage_range_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
3128			      struct btrfs_balance_args *bargs)
3129{
3130	struct btrfs_block_group_cache *cache;
3131	u64 chunk_used;
3132	u64 user_thresh_min;
3133	u64 user_thresh_max;
3134	int ret = 1;
3135
3136	cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3137	chunk_used = btrfs_block_group_used(&cache->item);
3138
3139	if (bargs->usage_min == 0)
3140		user_thresh_min = 0;
3141	else
3142		user_thresh_min = div_factor_fine(cache->key.offset,
3143					bargs->usage_min);
3144
3145	if (bargs->usage_max == 0)
3146		user_thresh_max = 1;
3147	else if (bargs->usage_max > 100)
3148		user_thresh_max = cache->key.offset;
3149	else
3150		user_thresh_max = div_factor_fine(cache->key.offset,
3151					bargs->usage_max);
3152
3153	if (user_thresh_min <= chunk_used && chunk_used < user_thresh_max)
3154		ret = 0;
3155
3156	btrfs_put_block_group(cache);
3157	return ret;
 
3158}
3159
3160static int chunk_usage_filter(struct btrfs_fs_info *fs_info,
3161		u64 chunk_offset, struct btrfs_balance_args *bargs)
3162{
3163	struct btrfs_block_group_cache *cache;
3164	u64 chunk_used, user_thresh;
3165	int ret = 1;
3166
3167	cache = btrfs_lookup_block_group(fs_info, chunk_offset);
3168	chunk_used = btrfs_block_group_used(&cache->item);
3169
3170	if (bargs->usage_min == 0)
3171		user_thresh = 1;
3172	else if (bargs->usage > 100)
3173		user_thresh = cache->key.offset;
3174	else
3175		user_thresh = div_factor_fine(cache->key.offset,
3176					      bargs->usage);
3177
3178	if (chunk_used < user_thresh)
3179		ret = 0;
3180
3181	btrfs_put_block_group(cache);
3182	return ret;
3183}
3184
3185static int chunk_devid_filter(struct extent_buffer *leaf,
3186			      struct btrfs_chunk *chunk,
3187			      struct btrfs_balance_args *bargs)
3188{
3189	struct btrfs_stripe *stripe;
3190	int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3191	int i;
3192
3193	for (i = 0; i < num_stripes; i++) {
3194		stripe = btrfs_stripe_nr(chunk, i);
3195		if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
3196			return 0;
3197	}
3198
3199	return 1;
3200}
3201
3202/* [pstart, pend) */
3203static int chunk_drange_filter(struct extent_buffer *leaf,
3204			       struct btrfs_chunk *chunk,
3205			       u64 chunk_offset,
3206			       struct btrfs_balance_args *bargs)
3207{
3208	struct btrfs_stripe *stripe;
3209	int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3210	u64 stripe_offset;
3211	u64 stripe_length;
3212	int factor;
3213	int i;
3214
3215	if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
3216		return 0;
3217
3218	if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
3219	     BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
3220		factor = num_stripes / 2;
3221	} else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
3222		factor = num_stripes - 1;
3223	} else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
3224		factor = num_stripes - 2;
3225	} else {
3226		factor = num_stripes;
3227	}
3228
3229	for (i = 0; i < num_stripes; i++) {
3230		stripe = btrfs_stripe_nr(chunk, i);
3231		if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
3232			continue;
3233
3234		stripe_offset = btrfs_stripe_offset(leaf, stripe);
3235		stripe_length = btrfs_chunk_length(leaf, chunk);
3236		stripe_length = div_u64(stripe_length, factor);
3237
3238		if (stripe_offset < bargs->pend &&
3239		    stripe_offset + stripe_length > bargs->pstart)
3240			return 0;
3241	}
3242
3243	return 1;
3244}
3245
3246/* [vstart, vend) */
3247static int chunk_vrange_filter(struct extent_buffer *leaf,
3248			       struct btrfs_chunk *chunk,
3249			       u64 chunk_offset,
3250			       struct btrfs_balance_args *bargs)
3251{
3252	if (chunk_offset < bargs->vend &&
3253	    chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
3254		/* at least part of the chunk is inside this vrange */
3255		return 0;
3256
3257	return 1;
3258}
3259
3260static int chunk_stripes_range_filter(struct extent_buffer *leaf,
3261			       struct btrfs_chunk *chunk,
3262			       struct btrfs_balance_args *bargs)
3263{
3264	int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3265
3266	if (bargs->stripes_min <= num_stripes
3267			&& num_stripes <= bargs->stripes_max)
3268		return 0;
3269
3270	return 1;
3271}
3272
3273static int chunk_soft_convert_filter(u64 chunk_type,
3274				     struct btrfs_balance_args *bargs)
3275{
3276	if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
3277		return 0;
3278
3279	chunk_type = chunk_to_extended(chunk_type) &
3280				BTRFS_EXTENDED_PROFILE_MASK;
3281
3282	if (bargs->target == chunk_type)
3283		return 1;
3284
3285	return 0;
3286}
3287
3288static int should_balance_chunk(struct btrfs_root *root,
3289				struct extent_buffer *leaf,
3290				struct btrfs_chunk *chunk, u64 chunk_offset)
3291{
3292	struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
3293	struct btrfs_balance_args *bargs = NULL;
3294	u64 chunk_type = btrfs_chunk_type(leaf, chunk);
3295
3296	/* type filter */
3297	if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
3298	      (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
3299		return 0;
3300	}
3301
3302	if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
3303		bargs = &bctl->data;
3304	else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
3305		bargs = &bctl->sys;
3306	else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
3307		bargs = &bctl->meta;
3308
3309	/* profiles filter */
3310	if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
3311	    chunk_profiles_filter(chunk_type, bargs)) {
3312		return 0;
3313	}
3314
3315	/* usage filter */
3316	if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
3317	    chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
3318		return 0;
3319	} else if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
3320	    chunk_usage_range_filter(bctl->fs_info, chunk_offset, bargs)) {
3321		return 0;
3322	}
3323
3324	/* devid filter */
3325	if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
3326	    chunk_devid_filter(leaf, chunk, bargs)) {
3327		return 0;
3328	}
3329
3330	/* drange filter, makes sense only with devid filter */
3331	if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
3332	    chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
3333		return 0;
3334	}
3335
3336	/* vrange filter */
3337	if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
3338	    chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
3339		return 0;
3340	}
3341
3342	/* stripes filter */
3343	if ((bargs->flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE) &&
3344	    chunk_stripes_range_filter(leaf, chunk, bargs)) {
3345		return 0;
3346	}
3347
3348	/* soft profile changing mode */
3349	if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
3350	    chunk_soft_convert_filter(chunk_type, bargs)) {
3351		return 0;
3352	}
3353
3354	/*
3355	 * limited by count, must be the last filter
3356	 */
3357	if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT)) {
3358		if (bargs->limit == 0)
3359			return 0;
3360		else
3361			bargs->limit--;
3362	} else if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)) {
3363		/*
3364		 * Same logic as the 'limit' filter; the minimum cannot be
3365		 * determined here because we do not have the global informatoin
3366		 * about the count of all chunks that satisfy the filters.
3367		 */
3368		if (bargs->limit_max == 0)
3369			return 0;
3370		else
3371			bargs->limit_max--;
3372	}
3373
3374	return 1;
3375}
3376
 
 
 
 
 
 
 
 
 
3377static int __btrfs_balance(struct btrfs_fs_info *fs_info)
3378{
3379	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3380	struct btrfs_root *chunk_root = fs_info->chunk_root;
3381	struct btrfs_root *dev_root = fs_info->dev_root;
3382	struct list_head *devices;
3383	struct btrfs_device *device;
3384	u64 old_size;
3385	u64 size_to_free;
3386	u64 chunk_type;
3387	struct btrfs_chunk *chunk;
3388	struct btrfs_path *path;
3389	struct btrfs_key key;
3390	struct btrfs_key found_key;
3391	struct btrfs_trans_handle *trans;
3392	struct extent_buffer *leaf;
3393	int slot;
3394	int ret;
3395	int enospc_errors = 0;
3396	bool counting = true;
3397	/* The single value limit and min/max limits use the same bytes in the */
3398	u64 limit_data = bctl->data.limit;
3399	u64 limit_meta = bctl->meta.limit;
3400	u64 limit_sys = bctl->sys.limit;
3401	u32 count_data = 0;
3402	u32 count_meta = 0;
3403	u32 count_sys = 0;
3404	int chunk_reserved = 0;
3405
3406	/* step one make some room on all the devices */
3407	devices = &fs_info->fs_devices->devices;
3408	list_for_each_entry(device, devices, dev_list) {
3409		old_size = btrfs_device_get_total_bytes(device);
3410		size_to_free = div_factor(old_size, 1);
3411		size_to_free = min_t(u64, size_to_free, SZ_1M);
3412		if (!device->writeable ||
3413		    btrfs_device_get_total_bytes(device) -
3414		    btrfs_device_get_bytes_used(device) > size_to_free ||
3415		    device->is_tgtdev_for_dev_replace)
3416			continue;
3417
3418		ret = btrfs_shrink_device(device, old_size - size_to_free);
3419		if (ret == -ENOSPC)
3420			break;
3421		BUG_ON(ret);
3422
3423		trans = btrfs_start_transaction(dev_root, 0);
3424		BUG_ON(IS_ERR(trans));
3425
3426		ret = btrfs_grow_device(trans, device, old_size);
3427		BUG_ON(ret);
3428
3429		btrfs_end_transaction(trans, dev_root);
3430	}
3431
3432	/* step two, relocate all the chunks */
3433	path = btrfs_alloc_path();
3434	if (!path) {
3435		ret = -ENOMEM;
3436		goto error;
3437	}
3438
3439	/* zero out stat counters */
3440	spin_lock(&fs_info->balance_lock);
3441	memset(&bctl->stat, 0, sizeof(bctl->stat));
3442	spin_unlock(&fs_info->balance_lock);
3443again:
3444	if (!counting) {
3445		/*
3446		 * The single value limit and min/max limits use the same bytes
3447		 * in the
3448		 */
3449		bctl->data.limit = limit_data;
3450		bctl->meta.limit = limit_meta;
3451		bctl->sys.limit = limit_sys;
3452	}
3453	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3454	key.offset = (u64)-1;
3455	key.type = BTRFS_CHUNK_ITEM_KEY;
3456
3457	while (1) {
3458		if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
3459		    atomic_read(&fs_info->balance_cancel_req)) {
3460			ret = -ECANCELED;
3461			goto error;
3462		}
3463
3464		mutex_lock(&fs_info->delete_unused_bgs_mutex);
3465		ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
3466		if (ret < 0) {
3467			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
3468			goto error;
3469		}
3470
3471		/*
3472		 * this shouldn't happen, it means the last relocate
3473		 * failed
3474		 */
3475		if (ret == 0)
3476			BUG(); /* FIXME break ? */
3477
3478		ret = btrfs_previous_item(chunk_root, path, 0,
3479					  BTRFS_CHUNK_ITEM_KEY);
3480		if (ret) {
3481			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
3482			ret = 0;
3483			break;
3484		}
3485
3486		leaf = path->nodes[0];
3487		slot = path->slots[0];
3488		btrfs_item_key_to_cpu(leaf, &found_key, slot);
3489
3490		if (found_key.objectid != key.objectid) {
3491			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
 
 
 
3492			break;
3493		}
3494
3495		chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3496		chunk_type = btrfs_chunk_type(leaf, chunk);
3497
3498		if (!counting) {
3499			spin_lock(&fs_info->balance_lock);
3500			bctl->stat.considered++;
3501			spin_unlock(&fs_info->balance_lock);
3502		}
3503
3504		ret = should_balance_chunk(chunk_root, leaf, chunk,
3505					   found_key.offset);
3506
3507		btrfs_release_path(path);
3508		if (!ret) {
3509			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
3510			goto loop;
3511		}
3512
3513		if (counting) {
3514			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
3515			spin_lock(&fs_info->balance_lock);
3516			bctl->stat.expected++;
3517			spin_unlock(&fs_info->balance_lock);
3518
3519			if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
3520				count_data++;
3521			else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
3522				count_sys++;
3523			else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
3524				count_meta++;
3525
3526			goto loop;
3527		}
3528
3529		/*
3530		 * Apply limit_min filter, no need to check if the LIMITS
3531		 * filter is used, limit_min is 0 by default
3532		 */
3533		if (((chunk_type & BTRFS_BLOCK_GROUP_DATA) &&
3534					count_data < bctl->data.limit_min)
3535				|| ((chunk_type & BTRFS_BLOCK_GROUP_METADATA) &&
3536					count_meta < bctl->meta.limit_min)
3537				|| ((chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) &&
3538					count_sys < bctl->sys.limit_min)) {
3539			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
3540			goto loop;
3541		}
3542
3543		if ((chunk_type & BTRFS_BLOCK_GROUP_DATA) && !chunk_reserved) {
3544			trans = btrfs_start_transaction(chunk_root, 0);
3545			if (IS_ERR(trans)) {
3546				mutex_unlock(&fs_info->delete_unused_bgs_mutex);
3547				ret = PTR_ERR(trans);
3548				goto error;
3549			}
3550
3551			ret = btrfs_force_chunk_alloc(trans, chunk_root,
3552						      BTRFS_BLOCK_GROUP_DATA);
3553			btrfs_end_transaction(trans, chunk_root);
3554			if (ret < 0) {
3555				mutex_unlock(&fs_info->delete_unused_bgs_mutex);
3556				goto error;
3557			}
3558			chunk_reserved = 1;
3559		}
3560
3561		ret = btrfs_relocate_chunk(chunk_root,
 
 
3562					   found_key.offset);
3563		mutex_unlock(&fs_info->delete_unused_bgs_mutex);
3564		if (ret && ret != -ENOSPC)
3565			goto error;
3566		if (ret == -ENOSPC) {
3567			enospc_errors++;
3568		} else {
3569			spin_lock(&fs_info->balance_lock);
3570			bctl->stat.completed++;
3571			spin_unlock(&fs_info->balance_lock);
3572		}
3573loop:
3574		if (found_key.offset == 0)
3575			break;
3576		key.offset = found_key.offset - 1;
3577	}
3578
3579	if (counting) {
3580		btrfs_release_path(path);
3581		counting = false;
3582		goto again;
3583	}
3584error:
3585	btrfs_free_path(path);
3586	if (enospc_errors) {
3587		btrfs_info(fs_info, "%d enospc errors during balance",
3588		       enospc_errors);
3589		if (!ret)
3590			ret = -ENOSPC;
3591	}
3592
3593	return ret;
3594}
3595
3596/**
3597 * alloc_profile_is_valid - see if a given profile is valid and reduced
3598 * @flags: profile to validate
3599 * @extended: if true @flags is treated as an extended profile
3600 */
3601static int alloc_profile_is_valid(u64 flags, int extended)
3602{
3603	u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3604			       BTRFS_BLOCK_GROUP_PROFILE_MASK);
3605
3606	flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3607
3608	/* 1) check that all other bits are zeroed */
3609	if (flags & ~mask)
3610		return 0;
3611
3612	/* 2) see if profile is reduced */
3613	if (flags == 0)
3614		return !extended; /* "0" is valid for usual profiles */
3615
3616	/* true if exactly one bit set */
3617	return (flags & (flags - 1)) == 0;
3618}
3619
3620static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3621{
3622	/* cancel requested || normal exit path */
3623	return atomic_read(&fs_info->balance_cancel_req) ||
3624		(atomic_read(&fs_info->balance_pause_req) == 0 &&
3625		 atomic_read(&fs_info->balance_cancel_req) == 0);
3626}
3627
3628static void __cancel_balance(struct btrfs_fs_info *fs_info)
3629{
3630	int ret;
3631
3632	unset_balance_control(fs_info);
3633	ret = del_balance_item(fs_info->tree_root);
3634	if (ret)
3635		btrfs_std_error(fs_info, ret, NULL);
3636
3637	atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3638}
3639
3640/* Non-zero return value signifies invalidity */
3641static inline int validate_convert_profile(struct btrfs_balance_args *bctl_arg,
3642		u64 allowed)
3643{
3644	return ((bctl_arg->flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3645		(!alloc_profile_is_valid(bctl_arg->target, 1) ||
3646		 (bctl_arg->target & ~allowed)));
3647}
3648
3649/*
3650 * Should be called with both balance and volume mutexes held
3651 */
3652int btrfs_balance(struct btrfs_balance_control *bctl,
3653		  struct btrfs_ioctl_balance_args *bargs)
3654{
3655	struct btrfs_fs_info *fs_info = bctl->fs_info;
3656	u64 allowed;
3657	int mixed = 0;
3658	int ret;
3659	u64 num_devices;
3660	unsigned seq;
3661
3662	if (btrfs_fs_closing(fs_info) ||
3663	    atomic_read(&fs_info->balance_pause_req) ||
3664	    atomic_read(&fs_info->balance_cancel_req)) {
3665		ret = -EINVAL;
3666		goto out;
3667	}
3668
3669	allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3670	if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3671		mixed = 1;
3672
3673	/*
3674	 * In case of mixed groups both data and meta should be picked,
3675	 * and identical options should be given for both of them.
3676	 */
3677	allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3678	if (mixed && (bctl->flags & allowed)) {
3679		if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3680		    !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3681		    memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3682			btrfs_err(fs_info, "with mixed groups data and "
3683				   "metadata balance options must be the same");
3684			ret = -EINVAL;
3685			goto out;
3686		}
3687	}
3688
3689	num_devices = fs_info->fs_devices->num_devices;
3690	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
3691	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3692		BUG_ON(num_devices < 1);
3693		num_devices--;
3694	}
3695	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
3696	allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3697	if (num_devices == 1)
3698		allowed |= BTRFS_BLOCK_GROUP_DUP;
3699	else if (num_devices > 1)
3700		allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3701	if (num_devices > 2)
3702		allowed |= BTRFS_BLOCK_GROUP_RAID5;
3703	if (num_devices > 3)
3704		allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
3705			    BTRFS_BLOCK_GROUP_RAID6);
3706	if (validate_convert_profile(&bctl->data, allowed)) {
3707		btrfs_err(fs_info, "unable to start balance with target "
3708			   "data profile %llu",
3709		       bctl->data.target);
 
3710		ret = -EINVAL;
3711		goto out;
3712	}
3713	if (validate_convert_profile(&bctl->meta, allowed)) {
3714		btrfs_err(fs_info,
3715			   "unable to start balance with target metadata profile %llu",
3716		       bctl->meta.target);
 
 
3717		ret = -EINVAL;
3718		goto out;
3719	}
3720	if (validate_convert_profile(&bctl->sys, allowed)) {
3721		btrfs_err(fs_info,
3722			   "unable to start balance with target system profile %llu",
3723		       bctl->sys.target);
 
 
 
 
 
 
 
 
 
 
3724		ret = -EINVAL;
3725		goto out;
3726	}
3727
3728	/* allow to reduce meta or sys integrity only if force set */
3729	allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3730			BTRFS_BLOCK_GROUP_RAID10 |
3731			BTRFS_BLOCK_GROUP_RAID5 |
3732			BTRFS_BLOCK_GROUP_RAID6;
3733	do {
3734		seq = read_seqbegin(&fs_info->profiles_lock);
3735
3736		if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3737		     (fs_info->avail_system_alloc_bits & allowed) &&
3738		     !(bctl->sys.target & allowed)) ||
3739		    ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3740		     (fs_info->avail_metadata_alloc_bits & allowed) &&
3741		     !(bctl->meta.target & allowed))) {
3742			if (bctl->flags & BTRFS_BALANCE_FORCE) {
3743				btrfs_info(fs_info, "force reducing metadata integrity");
3744			} else {
3745				btrfs_err(fs_info, "balance will reduce metadata "
3746					   "integrity, use force if you want this");
3747				ret = -EINVAL;
3748				goto out;
3749			}
3750		}
3751	} while (read_seqretry(&fs_info->profiles_lock, seq));
3752
3753	if (btrfs_get_num_tolerated_disk_barrier_failures(bctl->meta.target) <
3754		btrfs_get_num_tolerated_disk_barrier_failures(bctl->data.target)) {
3755		btrfs_warn(fs_info,
3756	"metadata profile 0x%llx has lower redundancy than data profile 0x%llx",
3757			bctl->meta.target, bctl->data.target);
3758	}
3759
3760	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3761		fs_info->num_tolerated_disk_barrier_failures = min(
3762			btrfs_calc_num_tolerated_disk_barrier_failures(fs_info),
3763			btrfs_get_num_tolerated_disk_barrier_failures(
3764				bctl->sys.target));
3765	}
3766
3767	ret = insert_balance_item(fs_info->tree_root, bctl);
3768	if (ret && ret != -EEXIST)
3769		goto out;
3770
3771	if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3772		BUG_ON(ret == -EEXIST);
3773		set_balance_control(bctl);
3774	} else {
3775		BUG_ON(ret != -EEXIST);
3776		spin_lock(&fs_info->balance_lock);
3777		update_balance_args(bctl);
3778		spin_unlock(&fs_info->balance_lock);
3779	}
3780
3781	atomic_inc(&fs_info->balance_running);
3782	mutex_unlock(&fs_info->balance_mutex);
3783
3784	ret = __btrfs_balance(fs_info);
3785
3786	mutex_lock(&fs_info->balance_mutex);
3787	atomic_dec(&fs_info->balance_running);
3788
3789	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3790		fs_info->num_tolerated_disk_barrier_failures =
3791			btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3792	}
3793
3794	if (bargs) {
3795		memset(bargs, 0, sizeof(*bargs));
3796		update_ioctl_balance_args(fs_info, 0, bargs);
3797	}
3798
3799	if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3800	    balance_need_close(fs_info)) {
3801		__cancel_balance(fs_info);
3802	}
3803
3804	wake_up(&fs_info->balance_wait_q);
3805
3806	return ret;
3807out:
3808	if (bctl->flags & BTRFS_BALANCE_RESUME)
3809		__cancel_balance(fs_info);
3810	else {
3811		kfree(bctl);
3812		atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3813	}
3814	return ret;
3815}
3816
3817static int balance_kthread(void *data)
3818{
3819	struct btrfs_fs_info *fs_info = data;
3820	int ret = 0;
3821
3822	mutex_lock(&fs_info->volume_mutex);
3823	mutex_lock(&fs_info->balance_mutex);
3824
3825	if (fs_info->balance_ctl) {
3826		btrfs_info(fs_info, "continuing balance");
3827		ret = btrfs_balance(fs_info->balance_ctl, NULL);
3828	}
3829
3830	mutex_unlock(&fs_info->balance_mutex);
3831	mutex_unlock(&fs_info->volume_mutex);
3832
3833	return ret;
3834}
3835
3836int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3837{
3838	struct task_struct *tsk;
3839
3840	spin_lock(&fs_info->balance_lock);
3841	if (!fs_info->balance_ctl) {
3842		spin_unlock(&fs_info->balance_lock);
3843		return 0;
3844	}
3845	spin_unlock(&fs_info->balance_lock);
3846
3847	if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3848		btrfs_info(fs_info, "force skipping balance");
3849		return 0;
3850	}
3851
3852	tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3853	return PTR_ERR_OR_ZERO(tsk);
 
 
 
3854}
3855
3856int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3857{
3858	struct btrfs_balance_control *bctl;
3859	struct btrfs_balance_item *item;
3860	struct btrfs_disk_balance_args disk_bargs;
3861	struct btrfs_path *path;
3862	struct extent_buffer *leaf;
3863	struct btrfs_key key;
3864	int ret;
3865
3866	path = btrfs_alloc_path();
3867	if (!path)
3868		return -ENOMEM;
3869
3870	key.objectid = BTRFS_BALANCE_OBJECTID;
3871	key.type = BTRFS_TEMPORARY_ITEM_KEY;
3872	key.offset = 0;
3873
3874	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3875	if (ret < 0)
3876		goto out;
3877	if (ret > 0) { /* ret = -ENOENT; */
3878		ret = 0;
3879		goto out;
3880	}
3881
3882	bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3883	if (!bctl) {
3884		ret = -ENOMEM;
3885		goto out;
3886	}
3887
3888	leaf = path->nodes[0];
3889	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3890
3891	bctl->fs_info = fs_info;
3892	bctl->flags = btrfs_balance_flags(leaf, item);
3893	bctl->flags |= BTRFS_BALANCE_RESUME;
3894
3895	btrfs_balance_data(leaf, item, &disk_bargs);
3896	btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3897	btrfs_balance_meta(leaf, item, &disk_bargs);
3898	btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3899	btrfs_balance_sys(leaf, item, &disk_bargs);
3900	btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3901
3902	WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3903
3904	mutex_lock(&fs_info->volume_mutex);
3905	mutex_lock(&fs_info->balance_mutex);
3906
3907	set_balance_control(bctl);
3908
3909	mutex_unlock(&fs_info->balance_mutex);
3910	mutex_unlock(&fs_info->volume_mutex);
3911out:
3912	btrfs_free_path(path);
3913	return ret;
3914}
3915
3916int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3917{
3918	int ret = 0;
3919
3920	mutex_lock(&fs_info->balance_mutex);
3921	if (!fs_info->balance_ctl) {
3922		mutex_unlock(&fs_info->balance_mutex);
3923		return -ENOTCONN;
3924	}
3925
3926	if (atomic_read(&fs_info->balance_running)) {
3927		atomic_inc(&fs_info->balance_pause_req);
3928		mutex_unlock(&fs_info->balance_mutex);
3929
3930		wait_event(fs_info->balance_wait_q,
3931			   atomic_read(&fs_info->balance_running) == 0);
3932
3933		mutex_lock(&fs_info->balance_mutex);
3934		/* we are good with balance_ctl ripped off from under us */
3935		BUG_ON(atomic_read(&fs_info->balance_running));
3936		atomic_dec(&fs_info->balance_pause_req);
3937	} else {
3938		ret = -ENOTCONN;
3939	}
3940
3941	mutex_unlock(&fs_info->balance_mutex);
3942	return ret;
3943}
3944
3945int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3946{
3947	if (fs_info->sb->s_flags & MS_RDONLY)
3948		return -EROFS;
3949
3950	mutex_lock(&fs_info->balance_mutex);
3951	if (!fs_info->balance_ctl) {
3952		mutex_unlock(&fs_info->balance_mutex);
3953		return -ENOTCONN;
3954	}
3955
3956	atomic_inc(&fs_info->balance_cancel_req);
3957	/*
3958	 * if we are running just wait and return, balance item is
3959	 * deleted in btrfs_balance in this case
3960	 */
3961	if (atomic_read(&fs_info->balance_running)) {
3962		mutex_unlock(&fs_info->balance_mutex);
3963		wait_event(fs_info->balance_wait_q,
3964			   atomic_read(&fs_info->balance_running) == 0);
3965		mutex_lock(&fs_info->balance_mutex);
3966	} else {
3967		/* __cancel_balance needs volume_mutex */
3968		mutex_unlock(&fs_info->balance_mutex);
3969		mutex_lock(&fs_info->volume_mutex);
3970		mutex_lock(&fs_info->balance_mutex);
3971
3972		if (fs_info->balance_ctl)
3973			__cancel_balance(fs_info);
3974
3975		mutex_unlock(&fs_info->volume_mutex);
3976	}
3977
3978	BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3979	atomic_dec(&fs_info->balance_cancel_req);
3980	mutex_unlock(&fs_info->balance_mutex);
3981	return 0;
3982}
3983
3984static int btrfs_uuid_scan_kthread(void *data)
3985{
3986	struct btrfs_fs_info *fs_info = data;
3987	struct btrfs_root *root = fs_info->tree_root;
3988	struct btrfs_key key;
3989	struct btrfs_key max_key;
3990	struct btrfs_path *path = NULL;
3991	int ret = 0;
3992	struct extent_buffer *eb;
3993	int slot;
3994	struct btrfs_root_item root_item;
3995	u32 item_size;
3996	struct btrfs_trans_handle *trans = NULL;
3997
3998	path = btrfs_alloc_path();
3999	if (!path) {
4000		ret = -ENOMEM;
4001		goto out;
4002	}
4003
4004	key.objectid = 0;
4005	key.type = BTRFS_ROOT_ITEM_KEY;
4006	key.offset = 0;
4007
4008	max_key.objectid = (u64)-1;
4009	max_key.type = BTRFS_ROOT_ITEM_KEY;
4010	max_key.offset = (u64)-1;
4011
4012	while (1) {
4013		ret = btrfs_search_forward(root, &key, path, 0);
4014		if (ret) {
4015			if (ret > 0)
4016				ret = 0;
4017			break;
4018		}
4019
4020		if (key.type != BTRFS_ROOT_ITEM_KEY ||
4021		    (key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
4022		     key.objectid != BTRFS_FS_TREE_OBJECTID) ||
4023		    key.objectid > BTRFS_LAST_FREE_OBJECTID)
4024			goto skip;
4025
4026		eb = path->nodes[0];
4027		slot = path->slots[0];
4028		item_size = btrfs_item_size_nr(eb, slot);
4029		if (item_size < sizeof(root_item))
4030			goto skip;
4031
4032		read_extent_buffer(eb, &root_item,
4033				   btrfs_item_ptr_offset(eb, slot),
4034				   (int)sizeof(root_item));
4035		if (btrfs_root_refs(&root_item) == 0)
4036			goto skip;
4037
4038		if (!btrfs_is_empty_uuid(root_item.uuid) ||
4039		    !btrfs_is_empty_uuid(root_item.received_uuid)) {
4040			if (trans)
4041				goto update_tree;
4042
4043			btrfs_release_path(path);
4044			/*
4045			 * 1 - subvol uuid item
4046			 * 1 - received_subvol uuid item
4047			 */
4048			trans = btrfs_start_transaction(fs_info->uuid_root, 2);
4049			if (IS_ERR(trans)) {
4050				ret = PTR_ERR(trans);
4051				break;
4052			}
4053			continue;
4054		} else {
4055			goto skip;
4056		}
4057update_tree:
4058		if (!btrfs_is_empty_uuid(root_item.uuid)) {
4059			ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
4060						  root_item.uuid,
4061						  BTRFS_UUID_KEY_SUBVOL,
4062						  key.objectid);
4063			if (ret < 0) {
4064				btrfs_warn(fs_info, "uuid_tree_add failed %d",
4065					ret);
4066				break;
4067			}
4068		}
4069
4070		if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
4071			ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
4072						  root_item.received_uuid,
4073						 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4074						  key.objectid);
4075			if (ret < 0) {
4076				btrfs_warn(fs_info, "uuid_tree_add failed %d",
4077					ret);
4078				break;
4079			}
4080		}
4081
4082skip:
4083		if (trans) {
4084			ret = btrfs_end_transaction(trans, fs_info->uuid_root);
4085			trans = NULL;
4086			if (ret)
4087				break;
4088		}
4089
4090		btrfs_release_path(path);
4091		if (key.offset < (u64)-1) {
4092			key.offset++;
4093		} else if (key.type < BTRFS_ROOT_ITEM_KEY) {
4094			key.offset = 0;
4095			key.type = BTRFS_ROOT_ITEM_KEY;
4096		} else if (key.objectid < (u64)-1) {
4097			key.offset = 0;
4098			key.type = BTRFS_ROOT_ITEM_KEY;
4099			key.objectid++;
4100		} else {
4101			break;
4102		}
4103		cond_resched();
4104	}
4105
4106out:
4107	btrfs_free_path(path);
4108	if (trans && !IS_ERR(trans))
4109		btrfs_end_transaction(trans, fs_info->uuid_root);
4110	if (ret)
4111		btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret);
4112	else
4113		fs_info->update_uuid_tree_gen = 1;
4114	up(&fs_info->uuid_tree_rescan_sem);
4115	return 0;
4116}
4117
4118/*
4119 * Callback for btrfs_uuid_tree_iterate().
4120 * returns:
4121 * 0	check succeeded, the entry is not outdated.
4122 * < 0	if an error occurred.
4123 * > 0	if the check failed, which means the caller shall remove the entry.
4124 */
4125static int btrfs_check_uuid_tree_entry(struct btrfs_fs_info *fs_info,
4126				       u8 *uuid, u8 type, u64 subid)
4127{
4128	struct btrfs_key key;
4129	int ret = 0;
4130	struct btrfs_root *subvol_root;
4131
4132	if (type != BTRFS_UUID_KEY_SUBVOL &&
4133	    type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
4134		goto out;
4135
4136	key.objectid = subid;
4137	key.type = BTRFS_ROOT_ITEM_KEY;
4138	key.offset = (u64)-1;
4139	subvol_root = btrfs_read_fs_root_no_name(fs_info, &key);
4140	if (IS_ERR(subvol_root)) {
4141		ret = PTR_ERR(subvol_root);
4142		if (ret == -ENOENT)
4143			ret = 1;
4144		goto out;
4145	}
4146
4147	switch (type) {
4148	case BTRFS_UUID_KEY_SUBVOL:
4149		if (memcmp(uuid, subvol_root->root_item.uuid, BTRFS_UUID_SIZE))
4150			ret = 1;
4151		break;
4152	case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
4153		if (memcmp(uuid, subvol_root->root_item.received_uuid,
4154			   BTRFS_UUID_SIZE))
4155			ret = 1;
4156		break;
4157	}
4158
4159out:
4160	return ret;
4161}
4162
4163static int btrfs_uuid_rescan_kthread(void *data)
4164{
4165	struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
4166	int ret;
4167
4168	/*
4169	 * 1st step is to iterate through the existing UUID tree and
4170	 * to delete all entries that contain outdated data.
4171	 * 2nd step is to add all missing entries to the UUID tree.
4172	 */
4173	ret = btrfs_uuid_tree_iterate(fs_info, btrfs_check_uuid_tree_entry);
4174	if (ret < 0) {
4175		btrfs_warn(fs_info, "iterating uuid_tree failed %d", ret);
4176		up(&fs_info->uuid_tree_rescan_sem);
4177		return ret;
4178	}
4179	return btrfs_uuid_scan_kthread(data);
4180}
4181
4182int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
4183{
4184	struct btrfs_trans_handle *trans;
4185	struct btrfs_root *tree_root = fs_info->tree_root;
4186	struct btrfs_root *uuid_root;
4187	struct task_struct *task;
4188	int ret;
4189
4190	/*
4191	 * 1 - root node
4192	 * 1 - root item
4193	 */
4194	trans = btrfs_start_transaction(tree_root, 2);
4195	if (IS_ERR(trans))
4196		return PTR_ERR(trans);
4197
4198	uuid_root = btrfs_create_tree(trans, fs_info,
4199				      BTRFS_UUID_TREE_OBJECTID);
4200	if (IS_ERR(uuid_root)) {
4201		ret = PTR_ERR(uuid_root);
4202		btrfs_abort_transaction(trans, tree_root, ret);
4203		return ret;
4204	}
4205
4206	fs_info->uuid_root = uuid_root;
4207
4208	ret = btrfs_commit_transaction(trans, tree_root);
4209	if (ret)
4210		return ret;
4211
4212	down(&fs_info->uuid_tree_rescan_sem);
4213	task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
4214	if (IS_ERR(task)) {
4215		/* fs_info->update_uuid_tree_gen remains 0 in all error case */
4216		btrfs_warn(fs_info, "failed to start uuid_scan task");
4217		up(&fs_info->uuid_tree_rescan_sem);
4218		return PTR_ERR(task);
4219	}
4220
4221	return 0;
4222}
4223
4224int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
4225{
4226	struct task_struct *task;
4227
4228	down(&fs_info->uuid_tree_rescan_sem);
4229	task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
4230	if (IS_ERR(task)) {
4231		/* fs_info->update_uuid_tree_gen remains 0 in all error case */
4232		btrfs_warn(fs_info, "failed to start uuid_rescan task");
4233		up(&fs_info->uuid_tree_rescan_sem);
4234		return PTR_ERR(task);
4235	}
4236
4237	return 0;
4238}
4239
4240/*
4241 * shrinking a device means finding all of the device extents past
4242 * the new size, and then following the back refs to the chunks.
4243 * The chunk relocation code actually frees the device extent
4244 */
4245int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
4246{
4247	struct btrfs_trans_handle *trans;
4248	struct btrfs_root *root = device->dev_root;
4249	struct btrfs_dev_extent *dev_extent = NULL;
4250	struct btrfs_path *path;
4251	u64 length;
 
 
4252	u64 chunk_offset;
4253	int ret;
4254	int slot;
4255	int failed = 0;
4256	bool retried = false;
4257	bool checked_pending_chunks = false;
4258	struct extent_buffer *l;
4259	struct btrfs_key key;
4260	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4261	u64 old_total = btrfs_super_total_bytes(super_copy);
4262	u64 old_size = btrfs_device_get_total_bytes(device);
4263	u64 diff = old_size - new_size;
4264
4265	if (device->is_tgtdev_for_dev_replace)
4266		return -EINVAL;
4267
4268	path = btrfs_alloc_path();
4269	if (!path)
4270		return -ENOMEM;
4271
4272	path->reada = READA_FORWARD;
4273
4274	lock_chunks(root);
4275
4276	btrfs_device_set_total_bytes(device, new_size);
4277	if (device->writeable) {
4278		device->fs_devices->total_rw_bytes -= diff;
4279		spin_lock(&root->fs_info->free_chunk_lock);
4280		root->fs_info->free_chunk_space -= diff;
4281		spin_unlock(&root->fs_info->free_chunk_lock);
4282	}
4283	unlock_chunks(root);
4284
4285again:
4286	key.objectid = device->devid;
4287	key.offset = (u64)-1;
4288	key.type = BTRFS_DEV_EXTENT_KEY;
4289
4290	do {
4291		mutex_lock(&root->fs_info->delete_unused_bgs_mutex);
4292		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4293		if (ret < 0) {
4294			mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
4295			goto done;
4296		}
4297
4298		ret = btrfs_previous_item(root, path, 0, key.type);
4299		if (ret)
4300			mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
4301		if (ret < 0)
4302			goto done;
4303		if (ret) {
4304			ret = 0;
4305			btrfs_release_path(path);
4306			break;
4307		}
4308
4309		l = path->nodes[0];
4310		slot = path->slots[0];
4311		btrfs_item_key_to_cpu(l, &key, path->slots[0]);
4312
4313		if (key.objectid != device->devid) {
4314			mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
4315			btrfs_release_path(path);
4316			break;
4317		}
4318
4319		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
4320		length = btrfs_dev_extent_length(l, dev_extent);
4321
4322		if (key.offset + length <= new_size) {
4323			mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
4324			btrfs_release_path(path);
4325			break;
4326		}
4327
 
 
4328		chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
4329		btrfs_release_path(path);
4330
4331		ret = btrfs_relocate_chunk(root, chunk_offset);
4332		mutex_unlock(&root->fs_info->delete_unused_bgs_mutex);
4333		if (ret && ret != -ENOSPC)
4334			goto done;
4335		if (ret == -ENOSPC)
4336			failed++;
4337	} while (key.offset-- > 0);
4338
4339	if (failed && !retried) {
4340		failed = 0;
4341		retried = true;
4342		goto again;
4343	} else if (failed && retried) {
4344		ret = -ENOSPC;
 
 
 
 
 
 
 
 
 
4345		goto done;
4346	}
4347
4348	/* Shrinking succeeded, else we would be at "done". */
4349	trans = btrfs_start_transaction(root, 0);
4350	if (IS_ERR(trans)) {
4351		ret = PTR_ERR(trans);
4352		goto done;
4353	}
4354
4355	lock_chunks(root);
4356
4357	/*
4358	 * We checked in the above loop all device extents that were already in
4359	 * the device tree. However before we have updated the device's
4360	 * total_bytes to the new size, we might have had chunk allocations that
4361	 * have not complete yet (new block groups attached to transaction
4362	 * handles), and therefore their device extents were not yet in the
4363	 * device tree and we missed them in the loop above. So if we have any
4364	 * pending chunk using a device extent that overlaps the device range
4365	 * that we can not use anymore, commit the current transaction and
4366	 * repeat the search on the device tree - this way we guarantee we will
4367	 * not have chunks using device extents that end beyond 'new_size'.
4368	 */
4369	if (!checked_pending_chunks) {
4370		u64 start = new_size;
4371		u64 len = old_size - new_size;
4372
4373		if (contains_pending_extent(trans->transaction, device,
4374					    &start, len)) {
4375			unlock_chunks(root);
4376			checked_pending_chunks = true;
4377			failed = 0;
4378			retried = false;
4379			ret = btrfs_commit_transaction(trans, root);
4380			if (ret)
4381				goto done;
4382			goto again;
4383		}
4384	}
4385
4386	btrfs_device_set_disk_total_bytes(device, new_size);
4387	if (list_empty(&device->resized_list))
4388		list_add_tail(&device->resized_list,
4389			      &root->fs_info->fs_devices->resized_devices);
4390
4391	WARN_ON(diff > old_total);
4392	btrfs_set_super_total_bytes(super_copy, old_total - diff);
4393	unlock_chunks(root);
4394
4395	/* Now btrfs_update_device() will change the on-disk size. */
4396	ret = btrfs_update_device(trans, device);
4397	btrfs_end_transaction(trans, root);
4398done:
4399	btrfs_free_path(path);
4400	if (ret) {
4401		lock_chunks(root);
4402		btrfs_device_set_total_bytes(device, old_size);
4403		if (device->writeable)
4404			device->fs_devices->total_rw_bytes += diff;
4405		spin_lock(&root->fs_info->free_chunk_lock);
4406		root->fs_info->free_chunk_space += diff;
4407		spin_unlock(&root->fs_info->free_chunk_lock);
4408		unlock_chunks(root);
4409	}
4410	return ret;
4411}
4412
4413static int btrfs_add_system_chunk(struct btrfs_root *root,
4414			   struct btrfs_key *key,
4415			   struct btrfs_chunk *chunk, int item_size)
4416{
4417	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4418	struct btrfs_disk_key disk_key;
4419	u32 array_size;
4420	u8 *ptr;
4421
4422	lock_chunks(root);
4423	array_size = btrfs_super_sys_array_size(super_copy);
4424	if (array_size + item_size + sizeof(disk_key)
4425			> BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
4426		unlock_chunks(root);
4427		return -EFBIG;
4428	}
4429
4430	ptr = super_copy->sys_chunk_array + array_size;
4431	btrfs_cpu_key_to_disk(&disk_key, key);
4432	memcpy(ptr, &disk_key, sizeof(disk_key));
4433	ptr += sizeof(disk_key);
4434	memcpy(ptr, chunk, item_size);
4435	item_size += sizeof(disk_key);
4436	btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
4437	unlock_chunks(root);
4438
4439	return 0;
4440}
4441
4442/*
4443 * sort the devices in descending order by max_avail, total_avail
4444 */
4445static int btrfs_cmp_device_info(const void *a, const void *b)
4446{
4447	const struct btrfs_device_info *di_a = a;
4448	const struct btrfs_device_info *di_b = b;
4449
4450	if (di_a->max_avail > di_b->max_avail)
4451		return -1;
4452	if (di_a->max_avail < di_b->max_avail)
4453		return 1;
4454	if (di_a->total_avail > di_b->total_avail)
4455		return -1;
4456	if (di_a->total_avail < di_b->total_avail)
4457		return 1;
4458	return 0;
4459}
4460
4461static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
4462{
4463	/* TODO allow them to set a preferred stripe size */
4464	return SZ_64K;
4465}
4466
4467static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
4468{
4469	if (!(type & BTRFS_BLOCK_GROUP_RAID56_MASK))
4470		return;
4471
4472	btrfs_set_fs_incompat(info, RAID56);
4473}
4474
4475#define BTRFS_MAX_DEVS(r) ((BTRFS_LEAF_DATA_SIZE(r)		\
4476			- sizeof(struct btrfs_item)		\
4477			- sizeof(struct btrfs_chunk))		\
4478			/ sizeof(struct btrfs_stripe) + 1)
4479
4480#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
4481				- 2 * sizeof(struct btrfs_disk_key)	\
4482				- 2 * sizeof(struct btrfs_chunk))	\
4483				/ sizeof(struct btrfs_stripe) + 1)
4484
4485static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4486			       struct btrfs_root *extent_root, u64 start,
4487			       u64 type)
 
 
4488{
4489	struct btrfs_fs_info *info = extent_root->fs_info;
4490	struct btrfs_fs_devices *fs_devices = info->fs_devices;
4491	struct list_head *cur;
4492	struct map_lookup *map = NULL;
4493	struct extent_map_tree *em_tree;
4494	struct extent_map *em;
4495	struct btrfs_device_info *devices_info = NULL;
4496	u64 total_avail;
4497	int num_stripes;	/* total number of stripes to allocate */
4498	int data_stripes;	/* number of stripes that count for
4499				   block group size */
4500	int sub_stripes;	/* sub_stripes info for map */
4501	int dev_stripes;	/* stripes per dev */
4502	int devs_max;		/* max devs to use */
4503	int devs_min;		/* min devs needed */
4504	int devs_increment;	/* ndevs has to be a multiple of this */
4505	int ncopies;		/* how many copies to data has */
4506	int ret;
4507	u64 max_stripe_size;
4508	u64 max_chunk_size;
4509	u64 stripe_size;
4510	u64 num_bytes;
4511	u64 raid_stripe_len = BTRFS_STRIPE_LEN;
4512	int ndevs;
4513	int i;
4514	int j;
4515	int index;
4516
4517	BUG_ON(!alloc_profile_is_valid(type, 0));
4518
4519	if (list_empty(&fs_devices->alloc_list))
4520		return -ENOSPC;
4521
4522	index = __get_raid_index(type);
 
 
 
 
 
4523
4524	sub_stripes = btrfs_raid_array[index].sub_stripes;
4525	dev_stripes = btrfs_raid_array[index].dev_stripes;
4526	devs_max = btrfs_raid_array[index].devs_max;
4527	devs_min = btrfs_raid_array[index].devs_min;
4528	devs_increment = btrfs_raid_array[index].devs_increment;
4529	ncopies = btrfs_raid_array[index].ncopies;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4530
4531	if (type & BTRFS_BLOCK_GROUP_DATA) {
4532		max_stripe_size = SZ_1G;
4533		max_chunk_size = 10 * max_stripe_size;
4534		if (!devs_max)
4535			devs_max = BTRFS_MAX_DEVS(info->chunk_root);
4536	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
4537		/* for larger filesystems, use larger metadata chunks */
4538		if (fs_devices->total_rw_bytes > 50ULL * SZ_1G)
4539			max_stripe_size = SZ_1G;
4540		else
4541			max_stripe_size = SZ_256M;
4542		max_chunk_size = max_stripe_size;
4543		if (!devs_max)
4544			devs_max = BTRFS_MAX_DEVS(info->chunk_root);
4545	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
4546		max_stripe_size = SZ_32M;
4547		max_chunk_size = 2 * max_stripe_size;
4548		if (!devs_max)
4549			devs_max = BTRFS_MAX_DEVS_SYS_CHUNK;
4550	} else {
4551		btrfs_err(info, "invalid chunk type 0x%llx requested",
4552		       type);
4553		BUG_ON(1);
4554	}
4555
4556	/* we don't want a chunk larger than 10% of writeable space */
4557	max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
4558			     max_chunk_size);
4559
4560	devices_info = kcalloc(fs_devices->rw_devices, sizeof(*devices_info),
4561			       GFP_NOFS);
4562	if (!devices_info)
4563		return -ENOMEM;
4564
4565	cur = fs_devices->alloc_list.next;
4566
4567	/*
4568	 * in the first pass through the devices list, we gather information
4569	 * about the available holes on each device.
4570	 */
4571	ndevs = 0;
4572	while (cur != &fs_devices->alloc_list) {
4573		struct btrfs_device *device;
4574		u64 max_avail;
4575		u64 dev_offset;
4576
4577		device = list_entry(cur, struct btrfs_device, dev_alloc_list);
4578
4579		cur = cur->next;
4580
4581		if (!device->writeable) {
4582			WARN(1, KERN_ERR
4583			       "BTRFS: read-only device in alloc_list\n");
 
4584			continue;
4585		}
4586
4587		if (!device->in_fs_metadata ||
4588		    device->is_tgtdev_for_dev_replace)
4589			continue;
4590
4591		if (device->total_bytes > device->bytes_used)
4592			total_avail = device->total_bytes - device->bytes_used;
4593		else
4594			total_avail = 0;
4595
4596		/* If there is no space on this device, skip it. */
4597		if (total_avail == 0)
4598			continue;
4599
4600		ret = find_free_dev_extent(trans, device,
4601					   max_stripe_size * dev_stripes,
4602					   &dev_offset, &max_avail);
4603		if (ret && ret != -ENOSPC)
4604			goto error;
4605
4606		if (ret == 0)
4607			max_avail = max_stripe_size * dev_stripes;
4608
4609		if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
4610			continue;
4611
4612		if (ndevs == fs_devices->rw_devices) {
4613			WARN(1, "%s: found more than %llu devices\n",
4614			     __func__, fs_devices->rw_devices);
4615			break;
4616		}
4617		devices_info[ndevs].dev_offset = dev_offset;
4618		devices_info[ndevs].max_avail = max_avail;
4619		devices_info[ndevs].total_avail = total_avail;
4620		devices_info[ndevs].dev = device;
4621		++ndevs;
4622	}
4623
4624	/*
4625	 * now sort the devices by hole size / available space
4626	 */
4627	sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
4628	     btrfs_cmp_device_info, NULL);
4629
4630	/* round down to number of usable stripes */
4631	ndevs -= ndevs % devs_increment;
4632
4633	if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
4634		ret = -ENOSPC;
4635		goto error;
4636	}
4637
4638	if (devs_max && ndevs > devs_max)
4639		ndevs = devs_max;
4640	/*
4641	 * the primary goal is to maximize the number of stripes, so use as many
4642	 * devices as possible, even if the stripes are not maximum sized.
4643	 */
4644	stripe_size = devices_info[ndevs-1].max_avail;
4645	num_stripes = ndevs * dev_stripes;
4646
4647	/*
4648	 * this will have to be fixed for RAID1 and RAID10 over
4649	 * more drives
4650	 */
4651	data_stripes = num_stripes / ncopies;
4652
4653	if (type & BTRFS_BLOCK_GROUP_RAID5) {
4654		raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
4655				 btrfs_super_stripesize(info->super_copy));
4656		data_stripes = num_stripes - 1;
4657	}
4658	if (type & BTRFS_BLOCK_GROUP_RAID6) {
4659		raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
4660				 btrfs_super_stripesize(info->super_copy));
4661		data_stripes = num_stripes - 2;
4662	}
4663
4664	/*
4665	 * Use the number of data stripes to figure out how big this chunk
4666	 * is really going to be in terms of logical address space,
4667	 * and compare that answer with the max chunk size
4668	 */
4669	if (stripe_size * data_stripes > max_chunk_size) {
4670		u64 mask = (1ULL << 24) - 1;
4671
4672		stripe_size = div_u64(max_chunk_size, data_stripes);
4673
4674		/* bump the answer up to a 16MB boundary */
4675		stripe_size = (stripe_size + mask) & ~mask;
4676
4677		/* but don't go higher than the limits we found
4678		 * while searching for free extents
4679		 */
4680		if (stripe_size > devices_info[ndevs-1].max_avail)
4681			stripe_size = devices_info[ndevs-1].max_avail;
4682	}
4683
4684	stripe_size = div_u64(stripe_size, dev_stripes);
4685
4686	/* align to BTRFS_STRIPE_LEN */
4687	stripe_size = div_u64(stripe_size, raid_stripe_len);
4688	stripe_size *= raid_stripe_len;
4689
4690	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4691	if (!map) {
4692		ret = -ENOMEM;
4693		goto error;
4694	}
4695	map->num_stripes = num_stripes;
4696
4697	for (i = 0; i < ndevs; ++i) {
4698		for (j = 0; j < dev_stripes; ++j) {
4699			int s = i * dev_stripes + j;
4700			map->stripes[s].dev = devices_info[i].dev;
4701			map->stripes[s].physical = devices_info[i].dev_offset +
4702						   j * stripe_size;
4703		}
4704	}
4705	map->sector_size = extent_root->sectorsize;
4706	map->stripe_len = raid_stripe_len;
4707	map->io_align = raid_stripe_len;
4708	map->io_width = raid_stripe_len;
4709	map->type = type;
4710	map->sub_stripes = sub_stripes;
4711
4712	num_bytes = stripe_size * data_stripes;
 
 
 
 
4713
4714	trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
4715
4716	em = alloc_extent_map();
4717	if (!em) {
4718		kfree(map);
4719		ret = -ENOMEM;
4720		goto error;
4721	}
4722	set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
4723	em->map_lookup = map;
4724	em->start = start;
4725	em->len = num_bytes;
4726	em->block_start = 0;
4727	em->block_len = em->len;
4728	em->orig_block_len = stripe_size;
4729
4730	em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4731	write_lock(&em_tree->lock);
4732	ret = add_extent_mapping(em_tree, em, 0);
4733	if (!ret) {
4734		list_add_tail(&em->list, &trans->transaction->pending_chunks);
4735		atomic_inc(&em->refs);
4736	}
4737	write_unlock(&em_tree->lock);
4738	if (ret) {
4739		free_extent_map(em);
4740		goto error;
4741	}
4742
4743	ret = btrfs_make_block_group(trans, extent_root, 0, type,
4744				     BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4745				     start, num_bytes);
4746	if (ret)
4747		goto error_del_extent;
4748
4749	for (i = 0; i < map->num_stripes; i++) {
4750		num_bytes = map->stripes[i].dev->bytes_used + stripe_size;
4751		btrfs_device_set_bytes_used(map->stripes[i].dev, num_bytes);
4752	}
4753
4754	spin_lock(&extent_root->fs_info->free_chunk_lock);
4755	extent_root->fs_info->free_chunk_space -= (stripe_size *
4756						   map->num_stripes);
4757	spin_unlock(&extent_root->fs_info->free_chunk_lock);
4758
4759	free_extent_map(em);
4760	check_raid56_incompat_flag(extent_root->fs_info, type);
 
 
 
 
 
 
 
4761
4762	kfree(devices_info);
4763	return 0;
4764
4765error_del_extent:
4766	write_lock(&em_tree->lock);
4767	remove_extent_mapping(em_tree, em);
4768	write_unlock(&em_tree->lock);
4769
4770	/* One for our allocation */
4771	free_extent_map(em);
4772	/* One for the tree reference */
4773	free_extent_map(em);
4774	/* One for the pending_chunks list reference */
4775	free_extent_map(em);
4776error:
 
4777	kfree(devices_info);
4778	return ret;
4779}
4780
4781int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
4782				struct btrfs_root *extent_root,
4783				u64 chunk_offset, u64 chunk_size)
 
4784{
 
4785	struct btrfs_key key;
4786	struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
4787	struct btrfs_device *device;
4788	struct btrfs_chunk *chunk;
4789	struct btrfs_stripe *stripe;
4790	struct extent_map_tree *em_tree;
4791	struct extent_map *em;
4792	struct map_lookup *map;
4793	size_t item_size;
4794	u64 dev_offset;
4795	u64 stripe_size;
4796	int i = 0;
4797	int ret = 0;
4798
4799	em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4800	read_lock(&em_tree->lock);
4801	em = lookup_extent_mapping(em_tree, chunk_offset, chunk_size);
4802	read_unlock(&em_tree->lock);
4803
4804	if (!em) {
4805		btrfs_crit(extent_root->fs_info, "unable to find logical "
4806			   "%Lu len %Lu", chunk_offset, chunk_size);
4807		return -EINVAL;
4808	}
4809
4810	if (em->start != chunk_offset || em->len != chunk_size) {
4811		btrfs_crit(extent_root->fs_info, "found a bad mapping, wanted"
4812			  " %Lu-%Lu, found %Lu-%Lu", chunk_offset,
4813			  chunk_size, em->start, em->len);
4814		free_extent_map(em);
4815		return -EINVAL;
4816	}
4817
4818	map = em->map_lookup;
4819	item_size = btrfs_chunk_item_size(map->num_stripes);
4820	stripe_size = em->orig_block_len;
4821
4822	chunk = kzalloc(item_size, GFP_NOFS);
4823	if (!chunk) {
4824		ret = -ENOMEM;
4825		goto out;
4826	}
4827
4828	/*
4829	 * Take the device list mutex to prevent races with the final phase of
4830	 * a device replace operation that replaces the device object associated
4831	 * with the map's stripes, because the device object's id can change
4832	 * at any time during that final phase of the device replace operation
4833	 * (dev-replace.c:btrfs_dev_replace_finishing()).
4834	 */
4835	mutex_lock(&chunk_root->fs_info->fs_devices->device_list_mutex);
4836	for (i = 0; i < map->num_stripes; i++) {
4837		device = map->stripes[i].dev;
4838		dev_offset = map->stripes[i].physical;
4839
 
 
 
 
4840		ret = btrfs_update_device(trans, device);
4841		if (ret)
4842			break;
4843		ret = btrfs_alloc_dev_extent(trans, device,
4844					     chunk_root->root_key.objectid,
4845					     BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4846					     chunk_offset, dev_offset,
4847					     stripe_size);
4848		if (ret)
4849			break;
4850	}
4851	if (ret) {
4852		mutex_unlock(&chunk_root->fs_info->fs_devices->device_list_mutex);
4853		goto out;
4854	}
4855
 
 
 
 
 
 
4856	stripe = &chunk->stripe;
4857	for (i = 0; i < map->num_stripes; i++) {
4858		device = map->stripes[i].dev;
4859		dev_offset = map->stripes[i].physical;
4860
4861		btrfs_set_stack_stripe_devid(stripe, device->devid);
4862		btrfs_set_stack_stripe_offset(stripe, dev_offset);
4863		memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4864		stripe++;
 
4865	}
4866	mutex_unlock(&chunk_root->fs_info->fs_devices->device_list_mutex);
4867
4868	btrfs_set_stack_chunk_length(chunk, chunk_size);
4869	btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4870	btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4871	btrfs_set_stack_chunk_type(chunk, map->type);
4872	btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4873	btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4874	btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4875	btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4876	btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4877
4878	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4879	key.type = BTRFS_CHUNK_ITEM_KEY;
4880	key.offset = chunk_offset;
4881
4882	ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
 
4883	if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4884		/*
4885		 * TODO: Cleanup of inserted chunk root in case of
4886		 * failure.
4887		 */
4888		ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4889					     item_size);
4890	}
4891
4892out:
4893	kfree(chunk);
4894	free_extent_map(em);
4895	return ret;
4896}
4897
4898/*
4899 * Chunk allocation falls into two parts. The first part does works
4900 * that make the new allocated chunk useable, but not do any operation
4901 * that modifies the chunk tree. The second part does the works that
4902 * require modifying the chunk tree. This division is important for the
4903 * bootstrap process of adding storage to a seed btrfs.
4904 */
4905int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4906		      struct btrfs_root *extent_root, u64 type)
4907{
4908	u64 chunk_offset;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4909
4910	ASSERT(mutex_is_locked(&extent_root->fs_info->chunk_mutex));
4911	chunk_offset = find_next_chunk(extent_root->fs_info);
4912	return __btrfs_alloc_chunk(trans, extent_root, chunk_offset, type);
 
 
4913}
4914
4915static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
4916					 struct btrfs_root *root,
4917					 struct btrfs_device *device)
4918{
4919	u64 chunk_offset;
4920	u64 sys_chunk_offset;
 
 
 
 
4921	u64 alloc_profile;
 
 
4922	struct btrfs_fs_info *fs_info = root->fs_info;
4923	struct btrfs_root *extent_root = fs_info->extent_root;
4924	int ret;
4925
4926	chunk_offset = find_next_chunk(fs_info);
4927	alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4928	ret = __btrfs_alloc_chunk(trans, extent_root, chunk_offset,
4929				  alloc_profile);
4930	if (ret)
4931		return ret;
4932
4933	sys_chunk_offset = find_next_chunk(root->fs_info);
4934	alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4935	ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
4936				  alloc_profile);
4937	return ret;
4938}
4939
4940static inline int btrfs_chunk_max_errors(struct map_lookup *map)
4941{
4942	int max_errors;
 
4943
4944	if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
4945			 BTRFS_BLOCK_GROUP_RAID10 |
4946			 BTRFS_BLOCK_GROUP_RAID5 |
4947			 BTRFS_BLOCK_GROUP_DUP)) {
4948		max_errors = 1;
4949	} else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
4950		max_errors = 2;
4951	} else {
4952		max_errors = 0;
4953	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4954
4955	return max_errors;
 
 
4956}
4957
4958int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4959{
4960	struct extent_map *em;
4961	struct map_lookup *map;
4962	struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4963	int readonly = 0;
4964	int miss_ndevs = 0;
4965	int i;
4966
4967	read_lock(&map_tree->map_tree.lock);
4968	em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4969	read_unlock(&map_tree->map_tree.lock);
4970	if (!em)
4971		return 1;
4972
4973	map = em->map_lookup;
4974	for (i = 0; i < map->num_stripes; i++) {
4975		if (map->stripes[i].dev->missing) {
4976			miss_ndevs++;
4977			continue;
4978		}
4979
 
 
4980		if (!map->stripes[i].dev->writeable) {
4981			readonly = 1;
4982			goto end;
4983		}
4984	}
4985
4986	/*
4987	 * If the number of missing devices is larger than max errors,
4988	 * we can not write the data into that chunk successfully, so
4989	 * set it readonly.
4990	 */
4991	if (miss_ndevs > btrfs_chunk_max_errors(map))
4992		readonly = 1;
4993end:
4994	free_extent_map(em);
4995	return readonly;
4996}
4997
4998void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4999{
5000	extent_map_tree_init(&tree->map_tree);
5001}
5002
5003void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
5004{
5005	struct extent_map *em;
5006
5007	while (1) {
5008		write_lock(&tree->map_tree.lock);
5009		em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
5010		if (em)
5011			remove_extent_mapping(&tree->map_tree, em);
5012		write_unlock(&tree->map_tree.lock);
5013		if (!em)
5014			break;
 
5015		/* once for us */
5016		free_extent_map(em);
5017		/* once for the tree */
5018		free_extent_map(em);
5019	}
5020}
5021
5022int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
5023{
5024	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
5025	struct extent_map *em;
5026	struct map_lookup *map;
5027	struct extent_map_tree *em_tree = &map_tree->map_tree;
5028	int ret;
5029
5030	read_lock(&em_tree->lock);
5031	em = lookup_extent_mapping(em_tree, logical, len);
5032	read_unlock(&em_tree->lock);
 
5033
5034	/*
5035	 * We could return errors for these cases, but that could get ugly and
5036	 * we'd probably do the same thing which is just not do anything else
5037	 * and exit, so return 1 so the callers don't try to use other copies.
5038	 */
5039	if (!em) {
5040		btrfs_crit(fs_info, "No mapping for %Lu-%Lu", logical,
5041			    logical+len);
5042		return 1;
5043	}
5044
5045	if (em->start > logical || em->start + em->len < logical) {
5046		btrfs_crit(fs_info, "Invalid mapping for %Lu-%Lu, got "
5047			    "%Lu-%Lu", logical, logical+len, em->start,
5048			    em->start + em->len);
5049		free_extent_map(em);
5050		return 1;
5051	}
5052
5053	map = em->map_lookup;
5054	if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
5055		ret = map->num_stripes;
5056	else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
5057		ret = map->sub_stripes;
5058	else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
5059		ret = 2;
5060	else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
5061		ret = 3;
5062	else
5063		ret = 1;
5064	free_extent_map(em);
5065
5066	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
5067	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
5068		ret++;
5069	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
5070
5071	return ret;
5072}
5073
5074unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
5075				    struct btrfs_mapping_tree *map_tree,
5076				    u64 logical)
5077{
5078	struct extent_map *em;
5079	struct map_lookup *map;
5080	struct extent_map_tree *em_tree = &map_tree->map_tree;
5081	unsigned long len = root->sectorsize;
5082
5083	read_lock(&em_tree->lock);
5084	em = lookup_extent_mapping(em_tree, logical, len);
5085	read_unlock(&em_tree->lock);
5086	BUG_ON(!em);
5087
5088	BUG_ON(em->start > logical || em->start + em->len < logical);
5089	map = em->map_lookup;
5090	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
5091		len = map->stripe_len * nr_data_stripes(map);
5092	free_extent_map(em);
5093	return len;
5094}
5095
5096int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
5097			   u64 logical, u64 len, int mirror_num)
5098{
5099	struct extent_map *em;
5100	struct map_lookup *map;
5101	struct extent_map_tree *em_tree = &map_tree->map_tree;
5102	int ret = 0;
5103
5104	read_lock(&em_tree->lock);
5105	em = lookup_extent_mapping(em_tree, logical, len);
5106	read_unlock(&em_tree->lock);
5107	BUG_ON(!em);
5108
5109	BUG_ON(em->start > logical || em->start + em->len < logical);
5110	map = em->map_lookup;
5111	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
5112		ret = 1;
5113	free_extent_map(em);
5114	return ret;
5115}
5116
5117static int find_live_mirror(struct btrfs_fs_info *fs_info,
5118			    struct map_lookup *map, int first, int num,
5119			    int optimal, int dev_replace_is_ongoing)
5120{
5121	int i;
5122	int tolerance;
5123	struct btrfs_device *srcdev;
5124
5125	if (dev_replace_is_ongoing &&
5126	    fs_info->dev_replace.cont_reading_from_srcdev_mode ==
5127	     BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
5128		srcdev = fs_info->dev_replace.srcdev;
5129	else
5130		srcdev = NULL;
5131
5132	/*
5133	 * try to avoid the drive that is the source drive for a
5134	 * dev-replace procedure, only choose it if no other non-missing
5135	 * mirror is available
5136	 */
5137	for (tolerance = 0; tolerance < 2; tolerance++) {
5138		if (map->stripes[optimal].dev->bdev &&
5139		    (tolerance || map->stripes[optimal].dev != srcdev))
5140			return optimal;
5141		for (i = first; i < first + num; i++) {
5142			if (map->stripes[i].dev->bdev &&
5143			    (tolerance || map->stripes[i].dev != srcdev))
5144				return i;
5145		}
5146	}
5147
5148	/* we couldn't find one that doesn't fail.  Just return something
5149	 * and the io error handling code will clean up eventually
5150	 */
5151	return optimal;
5152}
5153
5154static inline int parity_smaller(u64 a, u64 b)
5155{
5156	return a > b;
5157}
5158
5159/* Bubble-sort the stripe set to put the parity/syndrome stripes last */
5160static void sort_parity_stripes(struct btrfs_bio *bbio, int num_stripes)
5161{
5162	struct btrfs_bio_stripe s;
5163	int i;
5164	u64 l;
5165	int again = 1;
5166
5167	while (again) {
5168		again = 0;
5169		for (i = 0; i < num_stripes - 1; i++) {
5170			if (parity_smaller(bbio->raid_map[i],
5171					   bbio->raid_map[i+1])) {
5172				s = bbio->stripes[i];
5173				l = bbio->raid_map[i];
5174				bbio->stripes[i] = bbio->stripes[i+1];
5175				bbio->raid_map[i] = bbio->raid_map[i+1];
5176				bbio->stripes[i+1] = s;
5177				bbio->raid_map[i+1] = l;
5178
5179				again = 1;
5180			}
5181		}
5182	}
5183}
5184
5185static struct btrfs_bio *alloc_btrfs_bio(int total_stripes, int real_stripes)
5186{
5187	struct btrfs_bio *bbio = kzalloc(
5188		 /* the size of the btrfs_bio */
5189		sizeof(struct btrfs_bio) +
5190		/* plus the variable array for the stripes */
5191		sizeof(struct btrfs_bio_stripe) * (total_stripes) +
5192		/* plus the variable array for the tgt dev */
5193		sizeof(int) * (real_stripes) +
5194		/*
5195		 * plus the raid_map, which includes both the tgt dev
5196		 * and the stripes
5197		 */
5198		sizeof(u64) * (total_stripes),
5199		GFP_NOFS|__GFP_NOFAIL);
5200
5201	atomic_set(&bbio->error, 0);
5202	atomic_set(&bbio->refs, 1);
5203
5204	return bbio;
5205}
5206
5207void btrfs_get_bbio(struct btrfs_bio *bbio)
5208{
5209	WARN_ON(!atomic_read(&bbio->refs));
5210	atomic_inc(&bbio->refs);
5211}
5212
5213void btrfs_put_bbio(struct btrfs_bio *bbio)
5214{
5215	if (!bbio)
5216		return;
5217	if (atomic_dec_and_test(&bbio->refs))
5218		kfree(bbio);
5219}
5220
5221static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
5222			     u64 logical, u64 *length,
5223			     struct btrfs_bio **bbio_ret,
5224			     int mirror_num, int need_raid_map)
5225{
5226	struct extent_map *em;
5227	struct map_lookup *map;
5228	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
5229	struct extent_map_tree *em_tree = &map_tree->map_tree;
5230	u64 offset;
5231	u64 stripe_offset;
5232	u64 stripe_end_offset;
5233	u64 stripe_nr;
5234	u64 stripe_nr_orig;
5235	u64 stripe_nr_end;
5236	u64 stripe_len;
5237	u32 stripe_index;
5238	int i;
5239	int ret = 0;
5240	int num_stripes;
5241	int max_errors = 0;
5242	int tgtdev_indexes = 0;
5243	struct btrfs_bio *bbio = NULL;
5244	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
5245	int dev_replace_is_ongoing = 0;
5246	int num_alloc_stripes;
5247	int patch_the_first_stripe_for_dev_replace = 0;
5248	u64 physical_to_patch_in_first_stripe = 0;
5249	u64 raid56_full_stripe_start = (u64)-1;
5250
5251	read_lock(&em_tree->lock);
5252	em = lookup_extent_mapping(em_tree, logical, *length);
5253	read_unlock(&em_tree->lock);
5254
5255	if (!em) {
5256		btrfs_crit(fs_info, "unable to find logical %llu len %llu",
5257			logical, *length);
5258		return -EINVAL;
5259	}
5260
5261	if (em->start > logical || em->start + em->len < logical) {
5262		btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "
5263			   "found %Lu-%Lu", logical, em->start,
5264			   em->start + em->len);
5265		free_extent_map(em);
5266		return -EINVAL;
5267	}
5268
5269	map = em->map_lookup;
 
5270	offset = logical - em->start;
5271
5272	stripe_len = map->stripe_len;
 
 
5273	stripe_nr = offset;
5274	/*
5275	 * stripe_nr counts the total number of stripes we have to stride
5276	 * to get to this block
5277	 */
5278	stripe_nr = div64_u64(stripe_nr, stripe_len);
5279
5280	stripe_offset = stripe_nr * stripe_len;
5281	BUG_ON(offset < stripe_offset);
5282
5283	/* stripe_offset is the offset of this block in its stripe*/
5284	stripe_offset = offset - stripe_offset;
5285
5286	/* if we're here for raid56, we need to know the stripe aligned start */
5287	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
5288		unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
5289		raid56_full_stripe_start = offset;
5290
5291		/* allow a write of a full stripe, but make sure we don't
5292		 * allow straddling of stripes
5293		 */
5294		raid56_full_stripe_start = div64_u64(raid56_full_stripe_start,
5295				full_stripe_len);
5296		raid56_full_stripe_start *= full_stripe_len;
5297	}
5298
5299	if (rw & REQ_DISCARD) {
5300		/* we don't discard raid56 yet */
5301		if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
5302			ret = -EOPNOTSUPP;
5303			goto out;
5304		}
5305		*length = min_t(u64, em->len - offset, *length);
5306	} else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
5307		u64 max_len;
5308		/* For writes to RAID[56], allow a full stripeset across all disks.
5309		   For other RAID types and for RAID[56] reads, just allow a single
5310		   stripe (on a single disk). */
5311		if ((map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
5312		    (rw & REQ_WRITE)) {
5313			max_len = stripe_len * nr_data_stripes(map) -
5314				(offset - raid56_full_stripe_start);
5315		} else {
5316			/* we limit the length of each bio to what fits in a stripe */
5317			max_len = stripe_len - stripe_offset;
5318		}
5319		*length = min_t(u64, em->len - offset, max_len);
5320	} else {
5321		*length = em->len - offset;
5322	}
5323
5324	/* This is for when we're called from btrfs_merge_bio_hook() and all
5325	   it cares about is the length */
5326	if (!bbio_ret)
5327		goto out;
5328
5329	btrfs_dev_replace_lock(dev_replace, 0);
5330	dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
5331	if (!dev_replace_is_ongoing)
5332		btrfs_dev_replace_unlock(dev_replace, 0);
5333	else
5334		btrfs_dev_replace_set_lock_blocking(dev_replace);
5335
5336	if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
5337	    !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
5338	    dev_replace->tgtdev != NULL) {
5339		/*
5340		 * in dev-replace case, for repair case (that's the only
5341		 * case where the mirror is selected explicitly when
5342		 * calling btrfs_map_block), blocks left of the left cursor
5343		 * can also be read from the target drive.
5344		 * For REQ_GET_READ_MIRRORS, the target drive is added as
5345		 * the last one to the array of stripes. For READ, it also
5346		 * needs to be supported using the same mirror number.
5347		 * If the requested block is not left of the left cursor,
5348		 * EIO is returned. This can happen because btrfs_num_copies()
5349		 * returns one more in the dev-replace case.
5350		 */
5351		u64 tmp_length = *length;
5352		struct btrfs_bio *tmp_bbio = NULL;
5353		int tmp_num_stripes;
5354		u64 srcdev_devid = dev_replace->srcdev->devid;
5355		int index_srcdev = 0;
5356		int found = 0;
5357		u64 physical_of_found = 0;
5358
5359		ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
5360			     logical, &tmp_length, &tmp_bbio, 0, 0);
5361		if (ret) {
5362			WARN_ON(tmp_bbio != NULL);
5363			goto out;
5364		}
5365
5366		tmp_num_stripes = tmp_bbio->num_stripes;
5367		if (mirror_num > tmp_num_stripes) {
5368			/*
5369			 * REQ_GET_READ_MIRRORS does not contain this
5370			 * mirror, that means that the requested area
5371			 * is not left of the left cursor
5372			 */
5373			ret = -EIO;
5374			btrfs_put_bbio(tmp_bbio);
5375			goto out;
5376		}
5377
5378		/*
5379		 * process the rest of the function using the mirror_num
5380		 * of the source drive. Therefore look it up first.
5381		 * At the end, patch the device pointer to the one of the
5382		 * target drive.
5383		 */
5384		for (i = 0; i < tmp_num_stripes; i++) {
5385			if (tmp_bbio->stripes[i].dev->devid != srcdev_devid)
5386				continue;
5387
5388			/*
5389			 * In case of DUP, in order to keep it simple, only add
5390			 * the mirror with the lowest physical address
5391			 */
5392			if (found &&
5393			    physical_of_found <= tmp_bbio->stripes[i].physical)
5394				continue;
5395
5396			index_srcdev = i;
5397			found = 1;
5398			physical_of_found = tmp_bbio->stripes[i].physical;
5399		}
5400
5401		btrfs_put_bbio(tmp_bbio);
5402
5403		if (!found) {
5404			WARN_ON(1);
5405			ret = -EIO;
5406			goto out;
5407		}
5408
5409		mirror_num = index_srcdev + 1;
5410		patch_the_first_stripe_for_dev_replace = 1;
5411		physical_to_patch_in_first_stripe = physical_of_found;
5412	} else if (mirror_num > map->num_stripes) {
5413		mirror_num = 0;
5414	}
5415
5416	num_stripes = 1;
5417	stripe_index = 0;
5418	stripe_nr_orig = stripe_nr;
5419	stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
5420	stripe_nr_end = div_u64(stripe_nr_end, map->stripe_len);
 
5421	stripe_end_offset = stripe_nr_end * map->stripe_len -
5422			    (offset + *length);
5423
5424	if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
5425		if (rw & REQ_DISCARD)
5426			num_stripes = min_t(u64, map->num_stripes,
5427					    stripe_nr_end - stripe_nr_orig);
5428		stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
5429				&stripe_index);
5430		if (!(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)))
5431			mirror_num = 1;
5432	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
5433		if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
5434			num_stripes = map->num_stripes;
5435		else if (mirror_num)
5436			stripe_index = mirror_num - 1;
5437		else {
5438			stripe_index = find_live_mirror(fs_info, map, 0,
5439					    map->num_stripes,
5440					    current->pid % map->num_stripes,
5441					    dev_replace_is_ongoing);
5442			mirror_num = stripe_index + 1;
5443		}
5444
5445	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
5446		if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
5447			num_stripes = map->num_stripes;
5448		} else if (mirror_num) {
5449			stripe_index = mirror_num - 1;
5450		} else {
5451			mirror_num = 1;
5452		}
5453
5454	} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
5455		u32 factor = map->num_stripes / map->sub_stripes;
5456
5457		stripe_nr = div_u64_rem(stripe_nr, factor, &stripe_index);
5458		stripe_index *= map->sub_stripes;
5459
5460		if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
5461			num_stripes = map->sub_stripes;
5462		else if (rw & REQ_DISCARD)
5463			num_stripes = min_t(u64, map->sub_stripes *
5464					    (stripe_nr_end - stripe_nr_orig),
5465					    map->num_stripes);
5466		else if (mirror_num)
5467			stripe_index += mirror_num - 1;
5468		else {
5469			int old_stripe_index = stripe_index;
5470			stripe_index = find_live_mirror(fs_info, map,
5471					      stripe_index,
5472					      map->sub_stripes, stripe_index +
5473					      current->pid % map->sub_stripes,
5474					      dev_replace_is_ongoing);
5475			mirror_num = stripe_index - old_stripe_index + 1;
5476		}
5477
5478	} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
5479		if (need_raid_map &&
5480		    ((rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) ||
5481		     mirror_num > 1)) {
5482			/* push stripe_nr back to the start of the full stripe */
5483			stripe_nr = div_u64(raid56_full_stripe_start,
5484					stripe_len * nr_data_stripes(map));
5485
5486			/* RAID[56] write or recovery. Return all stripes */
5487			num_stripes = map->num_stripes;
5488			max_errors = nr_parity_stripes(map);
5489
5490			*length = map->stripe_len;
5491			stripe_index = 0;
5492			stripe_offset = 0;
5493		} else {
5494			/*
5495			 * Mirror #0 or #1 means the original data block.
5496			 * Mirror #2 is RAID5 parity block.
5497			 * Mirror #3 is RAID6 Q block.
5498			 */
5499			stripe_nr = div_u64_rem(stripe_nr,
5500					nr_data_stripes(map), &stripe_index);
5501			if (mirror_num > 1)
5502				stripe_index = nr_data_stripes(map) +
5503						mirror_num - 2;
5504
5505			/* We distribute the parity blocks across stripes */
5506			div_u64_rem(stripe_nr + stripe_index, map->num_stripes,
5507					&stripe_index);
5508			if (!(rw & (REQ_WRITE | REQ_DISCARD |
5509				    REQ_GET_READ_MIRRORS)) && mirror_num <= 1)
5510				mirror_num = 1;
5511		}
5512	} else {
5513		/*
5514		 * after this, stripe_nr is the number of stripes on this
5515		 * device we have to walk to find the data, and stripe_index is
5516		 * the number of our device in the stripe array
5517		 */
5518		stripe_nr = div_u64_rem(stripe_nr, map->num_stripes,
5519				&stripe_index);
5520		mirror_num = stripe_index + 1;
5521	}
5522	BUG_ON(stripe_index >= map->num_stripes);
5523
5524	num_alloc_stripes = num_stripes;
5525	if (dev_replace_is_ongoing) {
5526		if (rw & (REQ_WRITE | REQ_DISCARD))
5527			num_alloc_stripes <<= 1;
5528		if (rw & REQ_GET_READ_MIRRORS)
5529			num_alloc_stripes++;
5530		tgtdev_indexes = num_stripes;
5531	}
5532
5533	bbio = alloc_btrfs_bio(num_alloc_stripes, tgtdev_indexes);
5534	if (!bbio) {
5535		ret = -ENOMEM;
5536		goto out;
5537	}
5538	if (dev_replace_is_ongoing)
5539		bbio->tgtdev_map = (int *)(bbio->stripes + num_alloc_stripes);
5540
5541	/* build raid_map */
5542	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK &&
5543	    need_raid_map && ((rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) ||
5544	    mirror_num > 1)) {
5545		u64 tmp;
5546		unsigned rot;
5547
5548		bbio->raid_map = (u64 *)((void *)bbio->stripes +
5549				 sizeof(struct btrfs_bio_stripe) *
5550				 num_alloc_stripes +
5551				 sizeof(int) * tgtdev_indexes);
5552
5553		/* Work out the disk rotation on this stripe-set */
5554		div_u64_rem(stripe_nr, num_stripes, &rot);
5555
5556		/* Fill in the logical address of each stripe */
5557		tmp = stripe_nr * nr_data_stripes(map);
5558		for (i = 0; i < nr_data_stripes(map); i++)
5559			bbio->raid_map[(i+rot) % num_stripes] =
5560				em->start + (tmp + i) * map->stripe_len;
5561
5562		bbio->raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
5563		if (map->type & BTRFS_BLOCK_GROUP_RAID6)
5564			bbio->raid_map[(i+rot+1) % num_stripes] =
5565				RAID6_Q_STRIPE;
5566	}
5567
5568	if (rw & REQ_DISCARD) {
5569		u32 factor = 0;
5570		u32 sub_stripes = 0;
5571		u64 stripes_per_dev = 0;
5572		u32 remaining_stripes = 0;
5573		u32 last_stripe = 0;
5574
5575		if (map->type &
5576		    (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
5577			if (map->type & BTRFS_BLOCK_GROUP_RAID0)
5578				sub_stripes = 1;
5579			else
5580				sub_stripes = map->sub_stripes;
5581
5582			factor = map->num_stripes / sub_stripes;
5583			stripes_per_dev = div_u64_rem(stripe_nr_end -
5584						      stripe_nr_orig,
5585						      factor,
5586						      &remaining_stripes);
5587			div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
5588			last_stripe *= sub_stripes;
5589		}
5590
5591		for (i = 0; i < num_stripes; i++) {
5592			bbio->stripes[i].physical =
5593				map->stripes[stripe_index].physical +
5594				stripe_offset + stripe_nr * map->stripe_len;
5595			bbio->stripes[i].dev = map->stripes[stripe_index].dev;
5596
5597			if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
5598					 BTRFS_BLOCK_GROUP_RAID10)) {
5599				bbio->stripes[i].length = stripes_per_dev *
5600							  map->stripe_len;
5601
5602				if (i / sub_stripes < remaining_stripes)
5603					bbio->stripes[i].length +=
5604						map->stripe_len;
5605
5606				/*
5607				 * Special for the first stripe and
5608				 * the last stripe:
5609				 *
5610				 * |-------|...|-------|
5611				 *     |----------|
5612				 *    off     end_off
5613				 */
5614				if (i < sub_stripes)
5615					bbio->stripes[i].length -=
5616						stripe_offset;
5617
5618				if (stripe_index >= last_stripe &&
5619				    stripe_index <= (last_stripe +
5620						     sub_stripes - 1))
5621					bbio->stripes[i].length -=
5622						stripe_end_offset;
5623
5624				if (i == sub_stripes - 1)
5625					stripe_offset = 0;
5626			} else
5627				bbio->stripes[i].length = *length;
5628
5629			stripe_index++;
5630			if (stripe_index == map->num_stripes) {
5631				/* This could only happen for RAID0/10 */
5632				stripe_index = 0;
5633				stripe_nr++;
5634			}
5635		}
5636	} else {
5637		for (i = 0; i < num_stripes; i++) {
5638			bbio->stripes[i].physical =
5639				map->stripes[stripe_index].physical +
5640				stripe_offset +
5641				stripe_nr * map->stripe_len;
5642			bbio->stripes[i].dev =
5643				map->stripes[stripe_index].dev;
5644			stripe_index++;
5645		}
5646	}
5647
5648	if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
5649		max_errors = btrfs_chunk_max_errors(map);
5650
5651	if (bbio->raid_map)
5652		sort_parity_stripes(bbio, num_stripes);
5653
5654	tgtdev_indexes = 0;
5655	if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
5656	    dev_replace->tgtdev != NULL) {
5657		int index_where_to_add;
5658		u64 srcdev_devid = dev_replace->srcdev->devid;
5659
5660		/*
5661		 * duplicate the write operations while the dev replace
5662		 * procedure is running. Since the copying of the old disk
5663		 * to the new disk takes place at run time while the
5664		 * filesystem is mounted writable, the regular write
5665		 * operations to the old disk have to be duplicated to go
5666		 * to the new disk as well.
5667		 * Note that device->missing is handled by the caller, and
5668		 * that the write to the old disk is already set up in the
5669		 * stripes array.
5670		 */
5671		index_where_to_add = num_stripes;
5672		for (i = 0; i < num_stripes; i++) {
5673			if (bbio->stripes[i].dev->devid == srcdev_devid) {
5674				/* write to new disk, too */
5675				struct btrfs_bio_stripe *new =
5676					bbio->stripes + index_where_to_add;
5677				struct btrfs_bio_stripe *old =
5678					bbio->stripes + i;
5679
5680				new->physical = old->physical;
5681				new->length = old->length;
5682				new->dev = dev_replace->tgtdev;
5683				bbio->tgtdev_map[i] = index_where_to_add;
5684				index_where_to_add++;
5685				max_errors++;
5686				tgtdev_indexes++;
5687			}
5688		}
5689		num_stripes = index_where_to_add;
5690	} else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
5691		   dev_replace->tgtdev != NULL) {
5692		u64 srcdev_devid = dev_replace->srcdev->devid;
5693		int index_srcdev = 0;
5694		int found = 0;
5695		u64 physical_of_found = 0;
5696
5697		/*
5698		 * During the dev-replace procedure, the target drive can
5699		 * also be used to read data in case it is needed to repair
5700		 * a corrupt block elsewhere. This is possible if the
5701		 * requested area is left of the left cursor. In this area,
5702		 * the target drive is a full copy of the source drive.
5703		 */
5704		for (i = 0; i < num_stripes; i++) {
5705			if (bbio->stripes[i].dev->devid == srcdev_devid) {
5706				/*
5707				 * In case of DUP, in order to keep it
5708				 * simple, only add the mirror with the
5709				 * lowest physical address
5710				 */
5711				if (found &&
5712				    physical_of_found <=
5713				     bbio->stripes[i].physical)
5714					continue;
5715				index_srcdev = i;
5716				found = 1;
5717				physical_of_found = bbio->stripes[i].physical;
5718			}
5719		}
5720		if (found) {
5721			if (physical_of_found + map->stripe_len <=
5722			    dev_replace->cursor_left) {
5723				struct btrfs_bio_stripe *tgtdev_stripe =
5724					bbio->stripes + num_stripes;
5725
5726				tgtdev_stripe->physical = physical_of_found;
5727				tgtdev_stripe->length =
5728					bbio->stripes[index_srcdev].length;
5729				tgtdev_stripe->dev = dev_replace->tgtdev;
5730				bbio->tgtdev_map[index_srcdev] = num_stripes;
5731
5732				tgtdev_indexes++;
5733				num_stripes++;
5734			}
5735		}
5736	}
5737
5738	*bbio_ret = bbio;
5739	bbio->map_type = map->type;
5740	bbio->num_stripes = num_stripes;
5741	bbio->max_errors = max_errors;
5742	bbio->mirror_num = mirror_num;
5743	bbio->num_tgtdevs = tgtdev_indexes;
5744
5745	/*
5746	 * this is the case that REQ_READ && dev_replace_is_ongoing &&
5747	 * mirror_num == num_stripes + 1 && dev_replace target drive is
5748	 * available as a mirror
5749	 */
5750	if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
5751		WARN_ON(num_stripes > 1);
5752		bbio->stripes[0].dev = dev_replace->tgtdev;
5753		bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
5754		bbio->mirror_num = map->num_stripes + 1;
5755	}
5756out:
5757	if (dev_replace_is_ongoing) {
5758		btrfs_dev_replace_clear_lock_blocking(dev_replace);
5759		btrfs_dev_replace_unlock(dev_replace, 0);
5760	}
5761	free_extent_map(em);
5762	return ret;
5763}
5764
5765int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
5766		      u64 logical, u64 *length,
5767		      struct btrfs_bio **bbio_ret, int mirror_num)
5768{
5769	return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
5770				 mirror_num, 0);
5771}
5772
5773/* For Scrub/replace */
5774int btrfs_map_sblock(struct btrfs_fs_info *fs_info, int rw,
5775		     u64 logical, u64 *length,
5776		     struct btrfs_bio **bbio_ret, int mirror_num,
5777		     int need_raid_map)
5778{
5779	return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
5780				 mirror_num, need_raid_map);
5781}
5782
5783int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
5784		     u64 chunk_start, u64 physical, u64 devid,
5785		     u64 **logical, int *naddrs, int *stripe_len)
5786{
5787	struct extent_map_tree *em_tree = &map_tree->map_tree;
5788	struct extent_map *em;
5789	struct map_lookup *map;
5790	u64 *buf;
5791	u64 bytenr;
5792	u64 length;
5793	u64 stripe_nr;
5794	u64 rmap_len;
5795	int i, j, nr = 0;
5796
5797	read_lock(&em_tree->lock);
5798	em = lookup_extent_mapping(em_tree, chunk_start, 1);
5799	read_unlock(&em_tree->lock);
5800
5801	if (!em) {
5802		printk(KERN_ERR "BTRFS: couldn't find em for chunk %Lu\n",
5803		       chunk_start);
5804		return -EIO;
5805	}
5806
5807	if (em->start != chunk_start) {
5808		printk(KERN_ERR "BTRFS: bad chunk start, em=%Lu, wanted=%Lu\n",
5809		       em->start, chunk_start);
5810		free_extent_map(em);
5811		return -EIO;
5812	}
5813	map = em->map_lookup;
5814
5815	length = em->len;
5816	rmap_len = map->stripe_len;
5817
5818	if (map->type & BTRFS_BLOCK_GROUP_RAID10)
5819		length = div_u64(length, map->num_stripes / map->sub_stripes);
5820	else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
5821		length = div_u64(length, map->num_stripes);
5822	else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
5823		length = div_u64(length, nr_data_stripes(map));
5824		rmap_len = map->stripe_len * nr_data_stripes(map);
5825	}
5826
5827	buf = kcalloc(map->num_stripes, sizeof(u64), GFP_NOFS);
5828	BUG_ON(!buf); /* -ENOMEM */
5829
5830	for (i = 0; i < map->num_stripes; i++) {
5831		if (devid && map->stripes[i].dev->devid != devid)
5832			continue;
5833		if (map->stripes[i].physical > physical ||
5834		    map->stripes[i].physical + length <= physical)
5835			continue;
5836
5837		stripe_nr = physical - map->stripes[i].physical;
5838		stripe_nr = div_u64(stripe_nr, map->stripe_len);
5839
5840		if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
5841			stripe_nr = stripe_nr * map->num_stripes + i;
5842			stripe_nr = div_u64(stripe_nr, map->sub_stripes);
5843		} else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
5844			stripe_nr = stripe_nr * map->num_stripes + i;
5845		} /* else if RAID[56], multiply by nr_data_stripes().
5846		   * Alternatively, just use rmap_len below instead of
5847		   * map->stripe_len */
5848
5849		bytenr = chunk_start + stripe_nr * rmap_len;
5850		WARN_ON(nr >= map->num_stripes);
5851		for (j = 0; j < nr; j++) {
5852			if (buf[j] == bytenr)
5853				break;
5854		}
5855		if (j == nr) {
5856			WARN_ON(nr >= map->num_stripes);
5857			buf[nr++] = bytenr;
5858		}
5859	}
5860
5861	*logical = buf;
5862	*naddrs = nr;
5863	*stripe_len = rmap_len;
5864
5865	free_extent_map(em);
5866	return 0;
5867}
5868
5869static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio)
 
5870{
5871	bio->bi_private = bbio->private;
5872	bio->bi_end_io = bbio->end_io;
5873	bio_endio(bio);
 
 
 
 
 
 
 
 
 
 
 
 
 
5874
5875	btrfs_put_bbio(bbio);
 
 
5876}
5877
5878static void btrfs_end_bio(struct bio *bio)
5879{
5880	struct btrfs_bio *bbio = bio->bi_private;
5881	int is_orig_bio = 0;
5882
5883	if (bio->bi_error) {
5884		atomic_inc(&bbio->error);
5885		if (bio->bi_error == -EIO || bio->bi_error == -EREMOTEIO) {
5886			unsigned int stripe_index =
5887				btrfs_io_bio(bio)->stripe_index;
 
5888			struct btrfs_device *dev;
5889
5890			BUG_ON(stripe_index >= bbio->num_stripes);
5891			dev = bbio->stripes[stripe_index].dev;
5892			if (dev->bdev) {
5893				if (bio->bi_rw & WRITE)
5894					btrfs_dev_stat_inc(dev,
5895						BTRFS_DEV_STAT_WRITE_ERRS);
5896				else
5897					btrfs_dev_stat_inc(dev,
5898						BTRFS_DEV_STAT_READ_ERRS);
5899				if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
5900					btrfs_dev_stat_inc(dev,
5901						BTRFS_DEV_STAT_FLUSH_ERRS);
5902				btrfs_dev_stat_print_on_error(dev);
5903			}
5904		}
5905	}
5906
5907	if (bio == bbio->orig_bio)
5908		is_orig_bio = 1;
5909
5910	btrfs_bio_counter_dec(bbio->fs_info);
5911
5912	if (atomic_dec_and_test(&bbio->stripes_pending)) {
5913		if (!is_orig_bio) {
5914			bio_put(bio);
5915			bio = bbio->orig_bio;
5916		}
5917
5918		btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
 
 
5919		/* only send an error to the higher layers if it is
5920		 * beyond the tolerance of the btrfs bio
5921		 */
5922		if (atomic_read(&bbio->error) > bbio->max_errors) {
5923			bio->bi_error = -EIO;
5924		} else {
5925			/*
5926			 * this bio is actually up to date, we didn't
5927			 * go over the max number of errors
5928			 */
5929			bio->bi_error = 0;
 
5930		}
 
5931
5932		btrfs_end_bbio(bbio, bio);
5933	} else if (!is_orig_bio) {
5934		bio_put(bio);
5935	}
5936}
5937
 
 
 
 
 
 
 
5938/*
5939 * see run_scheduled_bios for a description of why bios are collected for
5940 * async submit.
5941 *
5942 * This will add one bio to the pending list for a device and make sure
5943 * the work struct is scheduled.
5944 */
5945static noinline void btrfs_schedule_bio(struct btrfs_root *root,
5946					struct btrfs_device *device,
5947					int rw, struct bio *bio)
5948{
5949	int should_queue = 1;
5950	struct btrfs_pending_bios *pending_bios;
5951
5952	if (device->missing || !device->bdev) {
5953		bio_io_error(bio);
5954		return;
5955	}
5956
5957	/* don't bother with additional async steps for reads, right now */
5958	if (!(rw & REQ_WRITE)) {
5959		bio_get(bio);
5960		btrfsic_submit_bio(rw, bio);
5961		bio_put(bio);
5962		return;
5963	}
5964
5965	/*
5966	 * nr_async_bios allows us to reliably return congestion to the
5967	 * higher layers.  Otherwise, the async bio makes it appear we have
5968	 * made progress against dirty pages when we've really just put it
5969	 * on a queue for later
5970	 */
5971	atomic_inc(&root->fs_info->nr_async_bios);
5972	WARN_ON(bio->bi_next);
5973	bio->bi_next = NULL;
5974	bio->bi_rw |= rw;
5975
5976	spin_lock(&device->io_lock);
5977	if (bio->bi_rw & REQ_SYNC)
5978		pending_bios = &device->pending_sync_bios;
5979	else
5980		pending_bios = &device->pending_bios;
5981
5982	if (pending_bios->tail)
5983		pending_bios->tail->bi_next = bio;
5984
5985	pending_bios->tail = bio;
5986	if (!pending_bios->head)
5987		pending_bios->head = bio;
5988	if (device->running_pending)
5989		should_queue = 0;
5990
5991	spin_unlock(&device->io_lock);
5992
5993	if (should_queue)
5994		btrfs_queue_work(root->fs_info->submit_workers,
5995				 &device->work);
5996}
5997
5998static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5999			      struct bio *bio, u64 physical, int dev_nr,
6000			      int rw, int async)
6001{
6002	struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
6003
6004	bio->bi_private = bbio;
6005	btrfs_io_bio(bio)->stripe_index = dev_nr;
6006	bio->bi_end_io = btrfs_end_bio;
6007	bio->bi_iter.bi_sector = physical >> 9;
6008#ifdef DEBUG
6009	{
6010		struct rcu_string *name;
6011
6012		rcu_read_lock();
6013		name = rcu_dereference(dev->name);
6014		pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
6015			 "(%s id %llu), size=%u\n", rw,
6016			 (u64)bio->bi_iter.bi_sector, (u_long)dev->bdev->bd_dev,
6017			 name->str, dev->devid, bio->bi_iter.bi_size);
6018		rcu_read_unlock();
6019	}
6020#endif
6021	bio->bi_bdev = dev->bdev;
6022
6023	btrfs_bio_counter_inc_noblocked(root->fs_info);
6024
6025	if (async)
6026		btrfs_schedule_bio(root, dev, rw, bio);
6027	else
6028		btrfsic_submit_bio(rw, bio);
6029}
6030
6031static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
6032{
6033	atomic_inc(&bbio->error);
6034	if (atomic_dec_and_test(&bbio->stripes_pending)) {
6035		/* Shoud be the original bio. */
6036		WARN_ON(bio != bbio->orig_bio);
6037
6038		btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
6039		bio->bi_iter.bi_sector = logical >> 9;
6040		bio->bi_error = -EIO;
6041		btrfs_end_bbio(bbio, bio);
6042	}
6043}
6044
6045int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
6046		  int mirror_num, int async_submit)
6047{
 
6048	struct btrfs_device *dev;
6049	struct bio *first_bio = bio;
6050	u64 logical = (u64)bio->bi_iter.bi_sector << 9;
6051	u64 length = 0;
6052	u64 map_length;
6053	int ret;
6054	int dev_nr;
6055	int total_devs;
6056	struct btrfs_bio *bbio = NULL;
6057
6058	length = bio->bi_iter.bi_size;
 
6059	map_length = length;
6060
6061	btrfs_bio_counter_inc_blocked(root->fs_info);
6062	ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
6063			      mirror_num, 1);
6064	if (ret) {
6065		btrfs_bio_counter_dec(root->fs_info);
6066		return ret;
6067	}
6068
6069	total_devs = bbio->num_stripes;
6070	bbio->orig_bio = first_bio;
6071	bbio->private = first_bio->bi_private;
6072	bbio->end_io = first_bio->bi_end_io;
6073	bbio->fs_info = root->fs_info;
6074	atomic_set(&bbio->stripes_pending, bbio->num_stripes);
6075
6076	if ((bbio->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&
6077	    ((rw & WRITE) || (mirror_num > 1))) {
6078		/* In this case, map_length has been set to the length of
6079		   a single stripe; not the whole write */
6080		if (rw & WRITE) {
6081			ret = raid56_parity_write(root, bio, bbio, map_length);
6082		} else {
6083			ret = raid56_parity_recover(root, bio, bbio, map_length,
6084						    mirror_num, 1);
6085		}
6086
6087		btrfs_bio_counter_dec(root->fs_info);
6088		return ret;
6089	}
6090
6091	if (map_length < length) {
6092		btrfs_crit(root->fs_info, "mapping failed logical %llu bio len %llu len %llu",
6093			logical, length, map_length);
 
 
6094		BUG();
6095	}
6096
6097	for (dev_nr = 0; dev_nr < total_devs; dev_nr++) {
6098		dev = bbio->stripes[dev_nr].dev;
6099		if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
6100			bbio_error(bbio, first_bio, logical);
6101			continue;
6102		}
6103
 
6104		if (dev_nr < total_devs - 1) {
6105			bio = btrfs_bio_clone(first_bio, GFP_NOFS);
6106			BUG_ON(!bio); /* -ENOMEM */
6107		} else
6108			bio = first_bio;
 
 
 
 
 
 
 
 
 
 
6109
6110		submit_stripe_bio(root, bbio, bio,
6111				  bbio->stripes[dev_nr].physical, dev_nr, rw,
6112				  async_submit);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6113	}
6114	btrfs_bio_counter_dec(root->fs_info);
6115	return 0;
6116}
6117
6118struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
6119				       u8 *uuid, u8 *fsid)
6120{
6121	struct btrfs_device *device;
6122	struct btrfs_fs_devices *cur_devices;
6123
6124	cur_devices = fs_info->fs_devices;
6125	while (cur_devices) {
6126		if (!fsid ||
6127		    !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
6128			device = __find_device(&cur_devices->devices,
6129					       devid, uuid);
6130			if (device)
6131				return device;
6132		}
6133		cur_devices = cur_devices->seed;
6134	}
6135	return NULL;
6136}
6137
6138static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
6139					    struct btrfs_fs_devices *fs_devices,
6140					    u64 devid, u8 *dev_uuid)
6141{
6142	struct btrfs_device *device;
 
6143
6144	device = btrfs_alloc_device(NULL, &devid, dev_uuid);
6145	if (IS_ERR(device))
6146		return NULL;
6147
6148	list_add(&device->dev_list, &fs_devices->devices);
 
 
 
6149	device->fs_devices = fs_devices;
6150	fs_devices->num_devices++;
6151
6152	device->missing = 1;
 
6153	fs_devices->missing_devices++;
6154
 
 
6155	return device;
6156}
6157
6158/**
6159 * btrfs_alloc_device - allocate struct btrfs_device
6160 * @fs_info:	used only for generating a new devid, can be NULL if
6161 *		devid is provided (i.e. @devid != NULL).
6162 * @devid:	a pointer to devid for this device.  If NULL a new devid
6163 *		is generated.
6164 * @uuid:	a pointer to UUID for this device.  If NULL a new UUID
6165 *		is generated.
6166 *
6167 * Return: a pointer to a new &struct btrfs_device on success; ERR_PTR()
6168 * on error.  Returned struct is not linked onto any lists and can be
6169 * destroyed with kfree() right away.
6170 */
6171struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
6172					const u64 *devid,
6173					const u8 *uuid)
6174{
6175	struct btrfs_device *dev;
6176	u64 tmp;
6177
6178	if (WARN_ON(!devid && !fs_info))
6179		return ERR_PTR(-EINVAL);
6180
6181	dev = __alloc_device();
6182	if (IS_ERR(dev))
6183		return dev;
6184
6185	if (devid)
6186		tmp = *devid;
6187	else {
6188		int ret;
6189
6190		ret = find_next_devid(fs_info, &tmp);
6191		if (ret) {
6192			kfree(dev);
6193			return ERR_PTR(ret);
6194		}
6195	}
6196	dev->devid = tmp;
6197
6198	if (uuid)
6199		memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE);
6200	else
6201		generate_random_uuid(dev->uuid);
6202
6203	btrfs_init_work(&dev->work, btrfs_submit_helper,
6204			pending_bios_fn, NULL, NULL);
6205
6206	return dev;
6207}
6208
6209static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
6210			  struct extent_buffer *leaf,
6211			  struct btrfs_chunk *chunk)
6212{
6213	struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
6214	struct map_lookup *map;
6215	struct extent_map *em;
6216	u64 logical;
6217	u64 length;
6218	u64 stripe_len;
6219	u64 devid;
6220	u8 uuid[BTRFS_UUID_SIZE];
6221	int num_stripes;
6222	int ret;
6223	int i;
6224
6225	logical = key->offset;
6226	length = btrfs_chunk_length(leaf, chunk);
6227	stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
6228	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
6229	/* Validation check */
6230	if (!num_stripes) {
6231		btrfs_err(root->fs_info, "invalid chunk num_stripes: %u",
6232			  num_stripes);
6233		return -EIO;
6234	}
6235	if (!IS_ALIGNED(logical, root->sectorsize)) {
6236		btrfs_err(root->fs_info,
6237			  "invalid chunk logical %llu", logical);
6238		return -EIO;
6239	}
6240	if (!length || !IS_ALIGNED(length, root->sectorsize)) {
6241		btrfs_err(root->fs_info,
6242			"invalid chunk length %llu", length);
6243		return -EIO;
6244	}
6245	if (!is_power_of_2(stripe_len)) {
6246		btrfs_err(root->fs_info, "invalid chunk stripe length: %llu",
6247			  stripe_len);
6248		return -EIO;
6249	}
6250	if (~(BTRFS_BLOCK_GROUP_TYPE_MASK | BTRFS_BLOCK_GROUP_PROFILE_MASK) &
6251	    btrfs_chunk_type(leaf, chunk)) {
6252		btrfs_err(root->fs_info, "unrecognized chunk type: %llu",
6253			  ~(BTRFS_BLOCK_GROUP_TYPE_MASK |
6254			    BTRFS_BLOCK_GROUP_PROFILE_MASK) &
6255			  btrfs_chunk_type(leaf, chunk));
6256		return -EIO;
6257	}
6258
6259	read_lock(&map_tree->map_tree.lock);
6260	em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
6261	read_unlock(&map_tree->map_tree.lock);
6262
6263	/* already mapped? */
6264	if (em && em->start <= logical && em->start + em->len > logical) {
6265		free_extent_map(em);
6266		return 0;
6267	} else if (em) {
6268		free_extent_map(em);
6269	}
6270
6271	em = alloc_extent_map();
6272	if (!em)
6273		return -ENOMEM;
 
6274	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
6275	if (!map) {
6276		free_extent_map(em);
6277		return -ENOMEM;
6278	}
6279
6280	set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
6281	em->map_lookup = map;
6282	em->start = logical;
6283	em->len = length;
6284	em->orig_start = 0;
6285	em->block_start = 0;
6286	em->block_len = em->len;
6287
6288	map->num_stripes = num_stripes;
6289	map->io_width = btrfs_chunk_io_width(leaf, chunk);
6290	map->io_align = btrfs_chunk_io_align(leaf, chunk);
6291	map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
6292	map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
6293	map->type = btrfs_chunk_type(leaf, chunk);
6294	map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
6295	for (i = 0; i < num_stripes; i++) {
6296		map->stripes[i].physical =
6297			btrfs_stripe_offset_nr(leaf, chunk, i);
6298		devid = btrfs_stripe_devid_nr(leaf, chunk, i);
6299		read_extent_buffer(leaf, uuid, (unsigned long)
6300				   btrfs_stripe_dev_uuid_nr(chunk, i),
6301				   BTRFS_UUID_SIZE);
6302		map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
6303							uuid, NULL);
6304		if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
 
6305			free_extent_map(em);
6306			return -EIO;
6307		}
6308		if (!map->stripes[i].dev) {
6309			map->stripes[i].dev =
6310				add_missing_dev(root, root->fs_info->fs_devices,
6311						devid, uuid);
6312			if (!map->stripes[i].dev) {
 
6313				free_extent_map(em);
6314				return -EIO;
6315			}
6316			btrfs_warn(root->fs_info, "devid %llu uuid %pU is missing",
6317						devid, uuid);
6318		}
6319		map->stripes[i].dev->in_fs_metadata = 1;
6320	}
6321
6322	write_lock(&map_tree->map_tree.lock);
6323	ret = add_extent_mapping(&map_tree->map_tree, em, 0);
6324	write_unlock(&map_tree->map_tree.lock);
6325	BUG_ON(ret); /* Tree corruption */
6326	free_extent_map(em);
6327
6328	return 0;
6329}
6330
6331static void fill_device_from_item(struct extent_buffer *leaf,
6332				 struct btrfs_dev_item *dev_item,
6333				 struct btrfs_device *device)
6334{
6335	unsigned long ptr;
6336
6337	device->devid = btrfs_device_id(leaf, dev_item);
6338	device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
6339	device->total_bytes = device->disk_total_bytes;
6340	device->commit_total_bytes = device->disk_total_bytes;
6341	device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
6342	device->commit_bytes_used = device->bytes_used;
6343	device->type = btrfs_device_type(leaf, dev_item);
6344	device->io_align = btrfs_device_io_align(leaf, dev_item);
6345	device->io_width = btrfs_device_io_width(leaf, dev_item);
6346	device->sector_size = btrfs_device_sector_size(leaf, dev_item);
6347	WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
6348	device->is_tgtdev_for_dev_replace = 0;
6349
6350	ptr = btrfs_device_uuid(dev_item);
6351	read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
6352}
6353
6354static struct btrfs_fs_devices *open_seed_devices(struct btrfs_root *root,
6355						  u8 *fsid)
6356{
6357	struct btrfs_fs_devices *fs_devices;
6358	int ret;
6359
6360	BUG_ON(!mutex_is_locked(&uuid_mutex));
6361
6362	fs_devices = root->fs_info->fs_devices->seed;
6363	while (fs_devices) {
6364		if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE))
6365			return fs_devices;
6366
 
6367		fs_devices = fs_devices->seed;
6368	}
6369
6370	fs_devices = find_fsid(fsid);
6371	if (!fs_devices) {
6372		if (!btrfs_test_opt(root, DEGRADED))
6373			return ERR_PTR(-ENOENT);
6374
6375		fs_devices = alloc_fs_devices(fsid);
6376		if (IS_ERR(fs_devices))
6377			return fs_devices;
6378
6379		fs_devices->seeding = 1;
6380		fs_devices->opened = 1;
6381		return fs_devices;
6382	}
6383
6384	fs_devices = clone_fs_devices(fs_devices);
6385	if (IS_ERR(fs_devices))
6386		return fs_devices;
 
 
6387
6388	ret = __btrfs_open_devices(fs_devices, FMODE_READ,
6389				   root->fs_info->bdev_holder);
6390	if (ret) {
6391		free_fs_devices(fs_devices);
6392		fs_devices = ERR_PTR(ret);
6393		goto out;
6394	}
6395
6396	if (!fs_devices->seeding) {
6397		__btrfs_close_devices(fs_devices);
6398		free_fs_devices(fs_devices);
6399		fs_devices = ERR_PTR(-EINVAL);
6400		goto out;
6401	}
6402
6403	fs_devices->seed = root->fs_info->fs_devices->seed;
6404	root->fs_info->fs_devices->seed = fs_devices;
6405out:
6406	return fs_devices;
6407}
6408
6409static int read_one_dev(struct btrfs_root *root,
6410			struct extent_buffer *leaf,
6411			struct btrfs_dev_item *dev_item)
6412{
6413	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
6414	struct btrfs_device *device;
6415	u64 devid;
6416	int ret;
6417	u8 fs_uuid[BTRFS_UUID_SIZE];
6418	u8 dev_uuid[BTRFS_UUID_SIZE];
6419
6420	devid = btrfs_device_id(leaf, dev_item);
6421	read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
 
6422			   BTRFS_UUID_SIZE);
6423	read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
 
6424			   BTRFS_UUID_SIZE);
6425
6426	if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
6427		fs_devices = open_seed_devices(root, fs_uuid);
6428		if (IS_ERR(fs_devices))
6429			return PTR_ERR(fs_devices);
6430	}
6431
6432	device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
6433	if (!device) {
6434		if (!btrfs_test_opt(root, DEGRADED))
6435			return -EIO;
6436
6437		device = add_missing_dev(root, fs_devices, devid, dev_uuid);
6438		if (!device)
6439			return -ENOMEM;
6440		btrfs_warn(root->fs_info, "devid %llu uuid %pU missing",
6441				devid, dev_uuid);
6442	} else {
6443		if (!device->bdev && !btrfs_test_opt(root, DEGRADED))
6444			return -EIO;
6445
6446		if(!device->bdev && !device->missing) {
6447			/*
6448			 * this happens when a device that was properly setup
6449			 * in the device info lists suddenly goes bad.
6450			 * device->bdev is NULL, and so we have to set
6451			 * device->missing to one here
6452			 */
6453			device->fs_devices->missing_devices++;
6454			device->missing = 1;
6455		}
6456
6457		/* Move the device to its own fs_devices */
6458		if (device->fs_devices != fs_devices) {
6459			ASSERT(device->missing);
6460
6461			list_move(&device->dev_list, &fs_devices->devices);
6462			device->fs_devices->num_devices--;
6463			fs_devices->num_devices++;
6464
6465			device->fs_devices->missing_devices--;
6466			fs_devices->missing_devices++;
6467
6468			device->fs_devices = fs_devices;
6469		}
6470	}
6471
6472	if (device->fs_devices != root->fs_info->fs_devices) {
6473		BUG_ON(device->writeable);
6474		if (device->generation !=
6475		    btrfs_device_generation(leaf, dev_item))
6476			return -EINVAL;
6477	}
6478
6479	fill_device_from_item(leaf, dev_item, device);
 
6480	device->in_fs_metadata = 1;
6481	if (device->writeable && !device->is_tgtdev_for_dev_replace) {
6482		device->fs_devices->total_rw_bytes += device->total_bytes;
6483		spin_lock(&root->fs_info->free_chunk_lock);
6484		root->fs_info->free_chunk_space += device->total_bytes -
6485			device->bytes_used;
6486		spin_unlock(&root->fs_info->free_chunk_lock);
6487	}
6488	ret = 0;
6489	return ret;
6490}
6491
6492int btrfs_read_sys_array(struct btrfs_root *root)
6493{
6494	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
6495	struct extent_buffer *sb;
6496	struct btrfs_disk_key *disk_key;
6497	struct btrfs_chunk *chunk;
6498	u8 *array_ptr;
6499	unsigned long sb_array_offset;
6500	int ret = 0;
6501	u32 num_stripes;
6502	u32 array_size;
6503	u32 len = 0;
6504	u32 cur_offset;
6505	struct btrfs_key key;
6506
6507	ASSERT(BTRFS_SUPER_INFO_SIZE <= root->nodesize);
6508	/*
6509	 * This will create extent buffer of nodesize, superblock size is
6510	 * fixed to BTRFS_SUPER_INFO_SIZE. If nodesize > sb size, this will
6511	 * overallocate but we can keep it as-is, only the first page is used.
6512	 */
6513	sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET);
6514	if (!sb)
6515		return -ENOMEM;
6516	set_extent_buffer_uptodate(sb);
6517	btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
6518	/*
6519	 * The sb extent buffer is artifical and just used to read the system array.
6520	 * set_extent_buffer_uptodate() call does not properly mark all it's
6521	 * pages up-to-date when the page is larger: extent does not cover the
6522	 * whole page and consequently check_page_uptodate does not find all
6523	 * the page's extents up-to-date (the hole beyond sb),
6524	 * write_extent_buffer then triggers a WARN_ON.
6525	 *
6526	 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
6527	 * but sb spans only this function. Add an explicit SetPageUptodate call
6528	 * to silence the warning eg. on PowerPC 64.
6529	 */
6530	if (PAGE_SIZE > BTRFS_SUPER_INFO_SIZE)
6531		SetPageUptodate(sb->pages[0]);
6532
6533	write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
6534	array_size = btrfs_super_sys_array_size(super_copy);
6535
6536	array_ptr = super_copy->sys_chunk_array;
6537	sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array);
6538	cur_offset = 0;
6539
6540	while (cur_offset < array_size) {
6541		disk_key = (struct btrfs_disk_key *)array_ptr;
6542		len = sizeof(*disk_key);
6543		if (cur_offset + len > array_size)
6544			goto out_short_read;
6545
 
 
6546		btrfs_disk_key_to_cpu(&key, disk_key);
6547
6548		array_ptr += len;
6549		sb_array_offset += len;
6550		cur_offset += len;
6551
6552		if (key.type == BTRFS_CHUNK_ITEM_KEY) {
6553			chunk = (struct btrfs_chunk *)sb_array_offset;
6554			/*
6555			 * At least one btrfs_chunk with one stripe must be
6556			 * present, exact stripe count check comes afterwards
6557			 */
6558			len = btrfs_chunk_item_size(1);
6559			if (cur_offset + len > array_size)
6560				goto out_short_read;
6561
6562			num_stripes = btrfs_chunk_num_stripes(sb, chunk);
6563			if (!num_stripes) {
6564				printk(KERN_ERR
6565	    "BTRFS: invalid number of stripes %u in sys_array at offset %u\n",
6566					num_stripes, cur_offset);
6567				ret = -EIO;
6568				break;
6569			}
6570
6571			len = btrfs_chunk_item_size(num_stripes);
6572			if (cur_offset + len > array_size)
6573				goto out_short_read;
6574
6575			ret = read_one_chunk(root, &key, sb, chunk);
6576			if (ret)
6577				break;
 
 
6578		} else {
6579			printk(KERN_ERR
6580		"BTRFS: unexpected item type %u in sys_array at offset %u\n",
6581				(u32)key.type, cur_offset);
6582			ret = -EIO;
6583			break;
6584		}
6585		array_ptr += len;
6586		sb_array_offset += len;
6587		cur_offset += len;
6588	}
6589	free_extent_buffer(sb);
6590	return ret;
6591
6592out_short_read:
6593	printk(KERN_ERR "BTRFS: sys_array too short to read %u bytes at offset %u\n",
6594			len, cur_offset);
6595	free_extent_buffer(sb);
6596	return -EIO;
6597}
6598
6599int btrfs_read_chunk_tree(struct btrfs_root *root)
6600{
6601	struct btrfs_path *path;
6602	struct extent_buffer *leaf;
6603	struct btrfs_key key;
6604	struct btrfs_key found_key;
6605	int ret;
6606	int slot;
6607
6608	root = root->fs_info->chunk_root;
6609
6610	path = btrfs_alloc_path();
6611	if (!path)
6612		return -ENOMEM;
6613
6614	mutex_lock(&uuid_mutex);
6615	lock_chunks(root);
6616
6617	/*
6618	 * Read all device items, and then all the chunk items. All
6619	 * device items are found before any chunk item (their object id
6620	 * is smaller than the lowest possible object id for a chunk
6621	 * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
6622	 */
6623	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
6624	key.offset = 0;
6625	key.type = 0;
 
6626	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6627	if (ret < 0)
6628		goto error;
6629	while (1) {
6630		leaf = path->nodes[0];
6631		slot = path->slots[0];
6632		if (slot >= btrfs_header_nritems(leaf)) {
6633			ret = btrfs_next_leaf(root, path);
6634			if (ret == 0)
6635				continue;
6636			if (ret < 0)
6637				goto error;
6638			break;
6639		}
6640		btrfs_item_key_to_cpu(leaf, &found_key, slot);
6641		if (found_key.type == BTRFS_DEV_ITEM_KEY) {
6642			struct btrfs_dev_item *dev_item;
6643			dev_item = btrfs_item_ptr(leaf, slot,
 
 
 
6644						  struct btrfs_dev_item);
6645			ret = read_one_dev(root, leaf, dev_item);
6646			if (ret)
6647				goto error;
 
6648		} else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
6649			struct btrfs_chunk *chunk;
6650			chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
6651			ret = read_one_chunk(root, &found_key, leaf, chunk);
6652			if (ret)
6653				goto error;
6654		}
6655		path->slots[0]++;
6656	}
 
 
 
 
 
6657	ret = 0;
6658error:
6659	unlock_chunks(root);
6660	mutex_unlock(&uuid_mutex);
6661
6662	btrfs_free_path(path);
6663	return ret;
6664}
6665
6666void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
6667{
6668	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6669	struct btrfs_device *device;
6670
6671	while (fs_devices) {
6672		mutex_lock(&fs_devices->device_list_mutex);
6673		list_for_each_entry(device, &fs_devices->devices, dev_list)
6674			device->dev_root = fs_info->dev_root;
6675		mutex_unlock(&fs_devices->device_list_mutex);
6676
6677		fs_devices = fs_devices->seed;
6678	}
6679}
6680
6681static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
6682{
6683	int i;
6684
6685	for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6686		btrfs_dev_stat_reset(dev, i);
6687}
6688
6689int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
6690{
6691	struct btrfs_key key;
6692	struct btrfs_key found_key;
6693	struct btrfs_root *dev_root = fs_info->dev_root;
6694	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6695	struct extent_buffer *eb;
6696	int slot;
6697	int ret = 0;
6698	struct btrfs_device *device;
6699	struct btrfs_path *path = NULL;
6700	int i;
6701
6702	path = btrfs_alloc_path();
6703	if (!path) {
6704		ret = -ENOMEM;
6705		goto out;
6706	}
6707
6708	mutex_lock(&fs_devices->device_list_mutex);
6709	list_for_each_entry(device, &fs_devices->devices, dev_list) {
6710		int item_size;
6711		struct btrfs_dev_stats_item *ptr;
6712
6713		key.objectid = BTRFS_DEV_STATS_OBJECTID;
6714		key.type = BTRFS_PERSISTENT_ITEM_KEY;
6715		key.offset = device->devid;
6716		ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
6717		if (ret) {
 
 
 
6718			__btrfs_reset_dev_stats(device);
6719			device->dev_stats_valid = 1;
6720			btrfs_release_path(path);
6721			continue;
6722		}
6723		slot = path->slots[0];
6724		eb = path->nodes[0];
6725		btrfs_item_key_to_cpu(eb, &found_key, slot);
6726		item_size = btrfs_item_size_nr(eb, slot);
6727
6728		ptr = btrfs_item_ptr(eb, slot,
6729				     struct btrfs_dev_stats_item);
6730
6731		for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6732			if (item_size >= (1 + i) * sizeof(__le64))
6733				btrfs_dev_stat_set(device, i,
6734					btrfs_dev_stats_value(eb, ptr, i));
6735			else
6736				btrfs_dev_stat_reset(device, i);
6737		}
6738
6739		device->dev_stats_valid = 1;
6740		btrfs_dev_stat_print_on_load(device);
6741		btrfs_release_path(path);
6742	}
6743	mutex_unlock(&fs_devices->device_list_mutex);
6744
6745out:
6746	btrfs_free_path(path);
6747	return ret < 0 ? ret : 0;
6748}
6749
6750static int update_dev_stat_item(struct btrfs_trans_handle *trans,
6751				struct btrfs_root *dev_root,
6752				struct btrfs_device *device)
6753{
6754	struct btrfs_path *path;
6755	struct btrfs_key key;
6756	struct extent_buffer *eb;
6757	struct btrfs_dev_stats_item *ptr;
6758	int ret;
6759	int i;
6760
6761	key.objectid = BTRFS_DEV_STATS_OBJECTID;
6762	key.type = BTRFS_PERSISTENT_ITEM_KEY;
6763	key.offset = device->devid;
6764
6765	path = btrfs_alloc_path();
6766	BUG_ON(!path);
6767	ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
6768	if (ret < 0) {
6769		btrfs_warn_in_rcu(dev_root->fs_info,
6770			"error %d while searching for dev_stats item for device %s",
6771			      ret, rcu_str_deref(device->name));
6772		goto out;
6773	}
6774
6775	if (ret == 0 &&
6776	    btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
6777		/* need to delete old one and insert a new one */
6778		ret = btrfs_del_item(trans, dev_root, path);
6779		if (ret != 0) {
6780			btrfs_warn_in_rcu(dev_root->fs_info,
6781				"delete too small dev_stats item for device %s failed %d",
6782				      rcu_str_deref(device->name), ret);
6783			goto out;
6784		}
6785		ret = 1;
6786	}
6787
6788	if (ret == 1) {
6789		/* need to insert a new item */
6790		btrfs_release_path(path);
6791		ret = btrfs_insert_empty_item(trans, dev_root, path,
6792					      &key, sizeof(*ptr));
6793		if (ret < 0) {
6794			btrfs_warn_in_rcu(dev_root->fs_info,
6795				"insert dev_stats item for device %s failed %d",
6796				rcu_str_deref(device->name), ret);
6797			goto out;
6798		}
6799	}
6800
6801	eb = path->nodes[0];
6802	ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
6803	for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6804		btrfs_set_dev_stats_value(eb, ptr, i,
6805					  btrfs_dev_stat_read(device, i));
6806	btrfs_mark_buffer_dirty(eb);
6807
6808out:
6809	btrfs_free_path(path);
6810	return ret;
6811}
6812
6813/*
6814 * called from commit_transaction. Writes all changed device stats to disk.
6815 */
6816int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
6817			struct btrfs_fs_info *fs_info)
6818{
6819	struct btrfs_root *dev_root = fs_info->dev_root;
6820	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6821	struct btrfs_device *device;
6822	int stats_cnt;
6823	int ret = 0;
6824
6825	mutex_lock(&fs_devices->device_list_mutex);
6826	list_for_each_entry(device, &fs_devices->devices, dev_list) {
6827		if (!device->dev_stats_valid || !btrfs_dev_stats_dirty(device))
6828			continue;
6829
6830		stats_cnt = atomic_read(&device->dev_stats_ccnt);
6831		ret = update_dev_stat_item(trans, dev_root, device);
6832		if (!ret)
6833			atomic_sub(stats_cnt, &device->dev_stats_ccnt);
6834	}
6835	mutex_unlock(&fs_devices->device_list_mutex);
6836
6837	return ret;
6838}
6839
6840void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
6841{
6842	btrfs_dev_stat_inc(dev, index);
6843	btrfs_dev_stat_print_on_error(dev);
6844}
6845
6846static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
6847{
6848	if (!dev->dev_stats_valid)
6849		return;
6850	btrfs_err_rl_in_rcu(dev->dev_root->fs_info,
6851		"bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u",
6852			   rcu_str_deref(dev->name),
6853			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6854			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6855			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6856			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
6857			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
 
 
6858}
6859
6860static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
6861{
6862	int i;
6863
6864	for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6865		if (btrfs_dev_stat_read(dev, i) != 0)
6866			break;
6867	if (i == BTRFS_DEV_STAT_VALUES_MAX)
6868		return; /* all values == 0, suppress message */
6869
6870	btrfs_info_in_rcu(dev->dev_root->fs_info,
6871		"bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u",
6872	       rcu_str_deref(dev->name),
6873	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6874	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6875	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6876	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
6877	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
6878}
6879
6880int btrfs_get_dev_stats(struct btrfs_root *root,
6881			struct btrfs_ioctl_get_dev_stats *stats)
 
6882{
6883	struct btrfs_device *dev;
6884	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
6885	int i;
6886
6887	mutex_lock(&fs_devices->device_list_mutex);
6888	dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
6889	mutex_unlock(&fs_devices->device_list_mutex);
6890
6891	if (!dev) {
6892		btrfs_warn(root->fs_info, "get dev_stats failed, device not found");
 
6893		return -ENODEV;
6894	} else if (!dev->dev_stats_valid) {
6895		btrfs_warn(root->fs_info, "get dev_stats failed, not yet valid");
 
6896		return -ENODEV;
6897	} else if (stats->flags & BTRFS_DEV_STATS_RESET) {
6898		for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6899			if (stats->nr_items > i)
6900				stats->values[i] =
6901					btrfs_dev_stat_read_and_reset(dev, i);
6902			else
6903				btrfs_dev_stat_reset(dev, i);
6904		}
6905	} else {
6906		for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6907			if (stats->nr_items > i)
6908				stats->values[i] = btrfs_dev_stat_read(dev, i);
6909	}
6910	if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
6911		stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
6912	return 0;
6913}
6914
6915void btrfs_scratch_superblocks(struct block_device *bdev, char *device_path)
6916{
6917	struct buffer_head *bh;
6918	struct btrfs_super_block *disk_super;
6919	int copy_num;
6920
6921	if (!bdev)
6922		return;
6923
6924	for (copy_num = 0; copy_num < BTRFS_SUPER_MIRROR_MAX;
6925		copy_num++) {
6926
6927		if (btrfs_read_dev_one_super(bdev, copy_num, &bh))
6928			continue;
6929
6930		disk_super = (struct btrfs_super_block *)bh->b_data;
6931
6932		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
6933		set_buffer_dirty(bh);
6934		sync_dirty_buffer(bh);
6935		brelse(bh);
6936	}
6937
6938	/* Notify udev that device has changed */
6939	btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
6940
6941	/* Update ctime/mtime for device path for libblkid */
6942	update_dev_time(device_path);
6943}
6944
6945/*
6946 * Update the size of all devices, which is used for writing out the
6947 * super blocks.
6948 */
6949void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info)
6950{
6951	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6952	struct btrfs_device *curr, *next;
6953
6954	if (list_empty(&fs_devices->resized_devices))
6955		return;
6956
6957	mutex_lock(&fs_devices->device_list_mutex);
6958	lock_chunks(fs_info->dev_root);
6959	list_for_each_entry_safe(curr, next, &fs_devices->resized_devices,
6960				 resized_list) {
6961		list_del_init(&curr->resized_list);
6962		curr->commit_total_bytes = curr->disk_total_bytes;
6963	}
6964	unlock_chunks(fs_info->dev_root);
6965	mutex_unlock(&fs_devices->device_list_mutex);
6966}
6967
6968/* Must be invoked during the transaction commit */
6969void btrfs_update_commit_device_bytes_used(struct btrfs_root *root,
6970					struct btrfs_transaction *transaction)
6971{
6972	struct extent_map *em;
6973	struct map_lookup *map;
6974	struct btrfs_device *dev;
6975	int i;
6976
6977	if (list_empty(&transaction->pending_chunks))
6978		return;
6979
6980	/* In order to kick the device replace finish process */
6981	lock_chunks(root);
6982	list_for_each_entry(em, &transaction->pending_chunks, list) {
6983		map = em->map_lookup;
6984
6985		for (i = 0; i < map->num_stripes; i++) {
6986			dev = map->stripes[i].dev;
6987			dev->commit_bytes_used = dev->bytes_used;
6988		}
6989	}
6990	unlock_chunks(root);
6991}
6992
6993void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info)
6994{
6995	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6996	while (fs_devices) {
6997		fs_devices->fs_info = fs_info;
6998		fs_devices = fs_devices->seed;
6999	}
7000}
7001
7002void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info)
7003{
7004	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
7005	while (fs_devices) {
7006		fs_devices->fs_info = NULL;
7007		fs_devices = fs_devices->seed;
7008	}
7009}
7010
7011static void btrfs_close_one_device(struct btrfs_device *device)
7012{
7013	struct btrfs_fs_devices *fs_devices = device->fs_devices;
7014	struct btrfs_device *new_device;
7015	struct rcu_string *name;
7016
7017	if (device->bdev)
7018		fs_devices->open_devices--;
7019
7020	if (device->writeable &&
7021	    device->devid != BTRFS_DEV_REPLACE_DEVID) {
7022		list_del_init(&device->dev_alloc_list);
7023		fs_devices->rw_devices--;
7024	}
7025
7026	if (device->missing)
7027		fs_devices->missing_devices--;
7028
7029	new_device = btrfs_alloc_device(NULL, &device->devid,
7030					device->uuid);
7031	BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
7032
7033	/* Safe because we are under uuid_mutex */
7034	if (device->name) {
7035		name = rcu_string_strdup(device->name->str, GFP_NOFS);
7036		BUG_ON(!name); /* -ENOMEM */
7037		rcu_assign_pointer(new_device->name, name);
7038	}
7039
7040	list_replace_rcu(&device->dev_list, &new_device->dev_list);
7041	new_device->fs_devices = device->fs_devices;
7042
7043	call_rcu(&device->rcu, free_device);
7044}