volumes.c 170.6 KB
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/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */
#include <linux/sched.h>
#include <linux/bio.h>
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#include <linux/slab.h>
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#include <linux/buffer_head.h>
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#include <linux/blkdev.h>
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#include <linux/random.h>
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#include <linux/iocontext.h>
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#include <linux/capability.h>
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#include <linux/ratelimit.h>
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#include <linux/kthread.h>
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#include <linux/raid/pq.h>
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#include <linux/semaphore.h>
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#include <asm/div64.h>
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#include "ctree.h"
#include "extent_map.h"
#include "disk-io.h"
#include "transaction.h"
#include "print-tree.h"
#include "volumes.h"
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#include "raid56.h"
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#include "async-thread.h"
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#include "check-integrity.h"
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#include "rcu-string.h"
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#include "math.h"
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#include "dev-replace.h"
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#include "sysfs.h"
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static int init_first_rw_device(struct btrfs_trans_handle *trans,
				struct btrfs_root *root,
				struct btrfs_device *device);
static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
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static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
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static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
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static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
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53
DEFINE_MUTEX(uuid_mutex);
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static LIST_HEAD(fs_uuids);

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static void lock_chunks(struct btrfs_root *root)
{
	mutex_lock(&root->fs_info->chunk_mutex);
}

static void unlock_chunks(struct btrfs_root *root)
{
	mutex_unlock(&root->fs_info->chunk_mutex);
}

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static struct btrfs_fs_devices *__alloc_fs_devices(void)
{
	struct btrfs_fs_devices *fs_devs;

	fs_devs = kzalloc(sizeof(*fs_devs), GFP_NOFS);
	if (!fs_devs)
		return ERR_PTR(-ENOMEM);

	mutex_init(&fs_devs->device_list_mutex);

	INIT_LIST_HEAD(&fs_devs->devices);
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	INIT_LIST_HEAD(&fs_devs->resized_devices);
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	INIT_LIST_HEAD(&fs_devs->alloc_list);
	INIT_LIST_HEAD(&fs_devs->list);

	return fs_devs;
}

/**
 * alloc_fs_devices - allocate struct btrfs_fs_devices
 * @fsid:	a pointer to UUID for this FS.  If NULL a new UUID is
 *		generated.
 *
 * Return: a pointer to a new &struct btrfs_fs_devices on success;
 * ERR_PTR() on error.  Returned struct is not linked onto any lists and
 * can be destroyed with kfree() right away.
 */
static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid)
{
	struct btrfs_fs_devices *fs_devs;

	fs_devs = __alloc_fs_devices();
	if (IS_ERR(fs_devs))
		return fs_devs;

	if (fsid)
		memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
	else
		generate_random_uuid(fs_devs->fsid);

	return fs_devs;
}

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static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
{
	struct btrfs_device *device;
	WARN_ON(fs_devices->opened);
	while (!list_empty(&fs_devices->devices)) {
		device = list_entry(fs_devices->devices.next,
				    struct btrfs_device, dev_list);
		list_del(&device->dev_list);
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		rcu_string_free(device->name);
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		kfree(device);
	}
	kfree(fs_devices);
}

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static void btrfs_kobject_uevent(struct block_device *bdev,
				 enum kobject_action action)
{
	int ret;

	ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
	if (ret)
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		pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
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			action,
			kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
			&disk_to_dev(bdev->bd_disk)->kobj);
}

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void btrfs_cleanup_fs_uuids(void)
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{
	struct btrfs_fs_devices *fs_devices;

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	while (!list_empty(&fs_uuids)) {
		fs_devices = list_entry(fs_uuids.next,
					struct btrfs_fs_devices, list);
		list_del(&fs_devices->list);
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		free_fs_devices(fs_devices);
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	}
}

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static struct btrfs_device *__alloc_device(void)
{
	struct btrfs_device *dev;

	dev = kzalloc(sizeof(*dev), GFP_NOFS);
	if (!dev)
		return ERR_PTR(-ENOMEM);

	INIT_LIST_HEAD(&dev->dev_list);
	INIT_LIST_HEAD(&dev->dev_alloc_list);
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	INIT_LIST_HEAD(&dev->resized_list);
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	spin_lock_init(&dev->io_lock);

	spin_lock_init(&dev->reada_lock);
	atomic_set(&dev->reada_in_flight, 0);
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	atomic_set(&dev->dev_stats_ccnt, 0);
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	INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_WAIT);
	INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_WAIT);

	return dev;
}

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static noinline struct btrfs_device *__find_device(struct list_head *head,
						   u64 devid, u8 *uuid)
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{
	struct btrfs_device *dev;

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	list_for_each_entry(dev, head, dev_list) {
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		if (dev->devid == devid &&
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		    (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
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			return dev;
180
		}
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	}
	return NULL;
}

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static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
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{
	struct btrfs_fs_devices *fs_devices;

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	list_for_each_entry(fs_devices, &fs_uuids, list) {
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		if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
			return fs_devices;
	}
	return NULL;
}

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static int
btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
		      int flush, struct block_device **bdev,
		      struct buffer_head **bh)
{
	int ret;

	*bdev = blkdev_get_by_path(device_path, flags, holder);

	if (IS_ERR(*bdev)) {
		ret = PTR_ERR(*bdev);
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		printk(KERN_INFO "BTRFS: open %s failed\n", device_path);
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		goto error;
	}

	if (flush)
		filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
	ret = set_blocksize(*bdev, 4096);
	if (ret) {
		blkdev_put(*bdev, flags);
		goto error;
	}
	invalidate_bdev(*bdev);
	*bh = btrfs_read_dev_super(*bdev);
	if (!*bh) {
		ret = -EINVAL;
		blkdev_put(*bdev, flags);
		goto error;
	}

	return 0;

error:
	*bdev = NULL;
	*bh = NULL;
	return ret;
}

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static void requeue_list(struct btrfs_pending_bios *pending_bios,
			struct bio *head, struct bio *tail)
{

	struct bio *old_head;

	old_head = pending_bios->head;
	pending_bios->head = head;
	if (pending_bios->tail)
		tail->bi_next = old_head;
	else
		pending_bios->tail = tail;
}

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/*
 * we try to collect pending bios for a device so we don't get a large
 * number of procs sending bios down to the same device.  This greatly
 * improves the schedulers ability to collect and merge the bios.
 *
 * But, it also turns into a long list of bios to process and that is sure
 * to eventually make the worker thread block.  The solution here is to
 * make some progress and then put this work struct back at the end of
 * the list if the block device is congested.  This way, multiple devices
 * can make progress from a single worker thread.
 */
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static noinline void run_scheduled_bios(struct btrfs_device *device)
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{
	struct bio *pending;
	struct backing_dev_info *bdi;
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	struct btrfs_fs_info *fs_info;
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	struct btrfs_pending_bios *pending_bios;
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	struct bio *tail;
	struct bio *cur;
	int again = 0;
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	unsigned long num_run;
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	unsigned long batch_run = 0;
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	unsigned long limit;
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	unsigned long last_waited = 0;
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	int force_reg = 0;
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	int sync_pending = 0;
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	struct blk_plug plug;

	/*
	 * this function runs all the bios we've collected for
	 * a particular device.  We don't want to wander off to
	 * another device without first sending all of these down.
	 * So, setup a plug here and finish it off before we return
	 */
	blk_start_plug(&plug);
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	bdi = blk_get_backing_dev_info(device->bdev);
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	fs_info = device->dev_root->fs_info;
	limit = btrfs_async_submit_limit(fs_info);
	limit = limit * 2 / 3;

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loop:
	spin_lock(&device->io_lock);

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loop_lock:
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	num_run = 0;
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	/* take all the bios off the list at once and process them
	 * later on (without the lock held).  But, remember the
	 * tail and other pointers so the bios can be properly reinserted
	 * into the list if we hit congestion
	 */
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	if (!force_reg && device->pending_sync_bios.head) {
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		pending_bios = &device->pending_sync_bios;
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		force_reg = 1;
	} else {
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		pending_bios = &device->pending_bios;
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		force_reg = 0;
	}
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	pending = pending_bios->head;
	tail = pending_bios->tail;
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	WARN_ON(pending && !tail);

	/*
	 * if pending was null this time around, no bios need processing
	 * at all and we can stop.  Otherwise it'll loop back up again
	 * and do an additional check so no bios are missed.
	 *
	 * device->running_pending is used to synchronize with the
	 * schedule_bio code.
	 */
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	if (device->pending_sync_bios.head == NULL &&
	    device->pending_bios.head == NULL) {
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		again = 0;
		device->running_pending = 0;
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	} else {
		again = 1;
		device->running_pending = 1;
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	}
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	pending_bios->head = NULL;
	pending_bios->tail = NULL;

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	spin_unlock(&device->io_lock);

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	while (pending) {
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		rmb();
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		/* we want to work on both lists, but do more bios on the
		 * sync list than the regular list
		 */
		if ((num_run > 32 &&
		    pending_bios != &device->pending_sync_bios &&
		    device->pending_sync_bios.head) ||
		   (num_run > 64 && pending_bios == &device->pending_sync_bios &&
		    device->pending_bios.head)) {
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			spin_lock(&device->io_lock);
			requeue_list(pending_bios, pending, tail);
			goto loop_lock;
		}

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		cur = pending;
		pending = pending->bi_next;
		cur->bi_next = NULL;
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		if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
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		    waitqueue_active(&fs_info->async_submit_wait))
			wake_up(&fs_info->async_submit_wait);
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		BUG_ON(atomic_read(&cur->bi_cnt) == 0);
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		/*
		 * if we're doing the sync list, record that our
		 * plug has some sync requests on it
		 *
		 * If we're doing the regular list and there are
		 * sync requests sitting around, unplug before
		 * we add more
		 */
		if (pending_bios == &device->pending_sync_bios) {
			sync_pending = 1;
		} else if (sync_pending) {
			blk_finish_plug(&plug);
			blk_start_plug(&plug);
			sync_pending = 0;
		}

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		btrfsic_submit_bio(cur->bi_rw, cur);
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		num_run++;
		batch_run++;
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		if (need_resched())
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			cond_resched();
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		/*
		 * we made progress, there is more work to do and the bdi
		 * is now congested.  Back off and let other work structs
		 * run instead
		 */
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		if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
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		    fs_info->fs_devices->open_devices > 1) {
389
			struct io_context *ioc;
390

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			ioc = current->io_context;

			/*
			 * the main goal here is that we don't want to
			 * block if we're going to be able to submit
			 * more requests without blocking.
			 *
			 * This code does two great things, it pokes into
			 * the elevator code from a filesystem _and_
			 * it makes assumptions about how batching works.
			 */
			if (ioc && ioc->nr_batch_requests > 0 &&
			    time_before(jiffies, ioc->last_waited + HZ/50UL) &&
			    (last_waited == 0 ||
			     ioc->last_waited == last_waited)) {
				/*
				 * we want to go through our batch of
				 * requests and stop.  So, we copy out
				 * the ioc->last_waited time and test
				 * against it before looping
				 */
				last_waited = ioc->last_waited;
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				if (need_resched())
414
					cond_resched();
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				continue;
			}
417
			spin_lock(&device->io_lock);
418
			requeue_list(pending_bios, pending, tail);
419
			device->running_pending = 1;
420 421

			spin_unlock(&device->io_lock);
422 423
			btrfs_queue_work(fs_info->submit_workers,
					 &device->work);
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			goto done;
		}
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		/* unplug every 64 requests just for good measure */
		if (batch_run % 64 == 0) {
			blk_finish_plug(&plug);
			blk_start_plug(&plug);
			sync_pending = 0;
		}
432
	}
433

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	cond_resched();
	if (again)
		goto loop;

	spin_lock(&device->io_lock);
	if (device->pending_bios.head || device->pending_sync_bios.head)
		goto loop_lock;
	spin_unlock(&device->io_lock);

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done:
444
	blk_finish_plug(&plug);
445 446
}

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static void pending_bios_fn(struct btrfs_work *work)
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{
	struct btrfs_device *device;

	device = container_of(work, struct btrfs_device, work);
	run_scheduled_bios(device);
}

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/*
 * Add new device to list of registered devices
 *
 * Returns:
 * 1   - first time device is seen
 * 0   - device already known
 * < 0 - error
 */
463
static noinline int device_list_add(const char *path,
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			   struct btrfs_super_block *disk_super,
			   u64 devid, struct btrfs_fs_devices **fs_devices_ret)
{
	struct btrfs_device *device;
	struct btrfs_fs_devices *fs_devices;
469
	struct rcu_string *name;
470
	int ret = 0;
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	u64 found_transid = btrfs_super_generation(disk_super);

	fs_devices = find_fsid(disk_super->fsid);
	if (!fs_devices) {
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		fs_devices = alloc_fs_devices(disk_super->fsid);
		if (IS_ERR(fs_devices))
			return PTR_ERR(fs_devices);

479
		list_add(&fs_devices->list, &fs_uuids);
480

481 482
		device = NULL;
	} else {
483 484
		device = __find_device(&fs_devices->devices, devid,
				       disk_super->dev_item.uuid);
485
	}
486

487
	if (!device) {
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		if (fs_devices->opened)
			return -EBUSY;

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		device = btrfs_alloc_device(NULL, &devid,
					    disk_super->dev_item.uuid);
		if (IS_ERR(device)) {
494
			/* we can safely leave the fs_devices entry around */
495
			return PTR_ERR(device);
496
		}
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		name = rcu_string_strdup(path, GFP_NOFS);
		if (!name) {
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			kfree(device);
			return -ENOMEM;
		}
503
		rcu_assign_pointer(device->name, name);
504

505
		mutex_lock(&fs_devices->device_list_mutex);
506
		list_add_rcu(&device->dev_list, &fs_devices->devices);
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		fs_devices->num_devices++;
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		mutex_unlock(&fs_devices->device_list_mutex);

510
		ret = 1;
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		device->fs_devices = fs_devices;
512
	} else if (!device->name || strcmp(device->name->str, path)) {
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		/*
		 * When FS is already mounted.
		 * 1. If you are here and if the device->name is NULL that
		 *    means this device was missing at time of FS mount.
		 * 2. If you are here and if the device->name is different
		 *    from 'path' that means either
		 *      a. The same device disappeared and reappeared with
		 *         different name. or
		 *      b. The missing-disk-which-was-replaced, has
		 *         reappeared now.
		 *
		 * We must allow 1 and 2a above. But 2b would be a spurious
		 * and unintentional.
		 *
		 * Further in case of 1 and 2a above, the disk at 'path'
		 * would have missed some transaction when it was away and
		 * in case of 2a the stale bdev has to be updated as well.
		 * 2b must not be allowed at all time.
		 */

		/*
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		 * For now, we do allow update to btrfs_fs_device through the
		 * btrfs dev scan cli after FS has been mounted.  We're still
		 * tracking a problem where systems fail mount by subvolume id
		 * when we reject replacement on a mounted FS.
538
		 */
539
		if (!fs_devices->opened && found_transid < device->generation) {
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			/*
			 * That is if the FS is _not_ mounted and if you
			 * are here, that means there is more than one
			 * disk with same uuid and devid.We keep the one
			 * with larger generation number or the last-in if
			 * generation are equal.
			 */
547
			return -EEXIST;
548
		}
549

550
		name = rcu_string_strdup(path, GFP_NOFS);
551 552
		if (!name)
			return -ENOMEM;
553 554
		rcu_string_free(device->name);
		rcu_assign_pointer(device->name, name);
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		if (device->missing) {
			fs_devices->missing_devices--;
			device->missing = 0;
		}
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	}

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	/*
	 * Unmount does not free the btrfs_device struct but would zero
	 * generation along with most of the other members. So just update
	 * it back. We need it to pick the disk with largest generation
	 * (as above).
	 */
	if (!fs_devices->opened)
		device->generation = found_transid;

570
	*fs_devices_ret = fs_devices;
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	return ret;
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}

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static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
{
	struct btrfs_fs_devices *fs_devices;
	struct btrfs_device *device;
	struct btrfs_device *orig_dev;

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	fs_devices = alloc_fs_devices(orig->fsid);
	if (IS_ERR(fs_devices))
		return fs_devices;
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585
	mutex_lock(&orig->device_list_mutex);
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	fs_devices->total_devices = orig->total_devices;
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588
	/* We have held the volume lock, it is safe to get the devices. */
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	list_for_each_entry(orig_dev, &orig->devices, dev_list) {
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		struct rcu_string *name;

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		device = btrfs_alloc_device(NULL, &orig_dev->devid,
					    orig_dev->uuid);
		if (IS_ERR(device))
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			goto error;

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		/*
		 * This is ok to do without rcu read locked because we hold the
		 * uuid mutex so nothing we touch in here is going to disappear.
		 */
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		if (orig_dev->name) {
			name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
			if (!name) {
				kfree(device);
				goto error;
			}
			rcu_assign_pointer(device->name, name);
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		}
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		list_add(&device->dev_list, &fs_devices->devices);
		device->fs_devices = fs_devices;
		fs_devices->num_devices++;
	}
614
	mutex_unlock(&orig->device_list_mutex);
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	return fs_devices;
error:
617
	mutex_unlock(&orig->device_list_mutex);
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	free_fs_devices(fs_devices);
	return ERR_PTR(-ENOMEM);
}

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void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
			       struct btrfs_fs_devices *fs_devices, int step)
624
{
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Qinghuang Feng 已提交
625
	struct btrfs_device *device, *next;
626
	struct btrfs_device *latest_dev = NULL;
627

628 629
	mutex_lock(&uuid_mutex);
again:
630
	/* This is the initialized path, it is safe to release the devices. */
Q
Qinghuang Feng 已提交
631
	list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
632
		if (device->in_fs_metadata) {
633
			if (!device->is_tgtdev_for_dev_replace &&
634 635 636
			    (!latest_dev ||
			     device->generation > latest_dev->generation)) {
				latest_dev = device;
637
			}
Y
Yan Zheng 已提交
638
			continue;
639
		}
Y
Yan Zheng 已提交
640

641 642 643 644 645 646 647 648 649 650 651 652 653 654 655
		if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
			/*
			 * In the first step, keep the device which has
			 * the correct fsid and the devid that is used
			 * for the dev_replace procedure.
			 * In the second step, the dev_replace state is
			 * read from the device tree and it is known
			 * whether the procedure is really active or
			 * not, which means whether this device is
			 * used or whether it should be removed.
			 */
			if (step == 0 || device->is_tgtdev_for_dev_replace) {
				continue;
			}
		}
Y
Yan Zheng 已提交
656
		if (device->bdev) {
657
			blkdev_put(device->bdev, device->mode);
Y
Yan Zheng 已提交
658 659 660 661 662 663
			device->bdev = NULL;
			fs_devices->open_devices--;
		}
		if (device->writeable) {
			list_del_init(&device->dev_alloc_list);
			device->writeable = 0;
664 665
			if (!device->is_tgtdev_for_dev_replace)
				fs_devices->rw_devices--;
Y
Yan Zheng 已提交
666
		}
Y
Yan Zheng 已提交
667 668
		list_del_init(&device->dev_list);
		fs_devices->num_devices--;
669
		rcu_string_free(device->name);
Y
Yan Zheng 已提交
670
		kfree(device);
671
	}
Y
Yan Zheng 已提交
672 673 674 675 676 677

	if (fs_devices->seed) {
		fs_devices = fs_devices->seed;
		goto again;
	}

678
	fs_devices->latest_bdev = latest_dev->bdev;
679

680 681
	mutex_unlock(&uuid_mutex);
}
682

683 684 685 686 687 688 689 690 691
static void __free_device(struct work_struct *work)
{
	struct btrfs_device *device;

	device = container_of(work, struct btrfs_device, rcu_work);

	if (device->bdev)
		blkdev_put(device->bdev, device->mode);

692
	rcu_string_free(device->name);
693 694 695 696 697 698 699 700 701 702 703 704 705
	kfree(device);
}

static void free_device(struct rcu_head *head)
{
	struct btrfs_device *device;

	device = container_of(head, struct btrfs_device, rcu);

	INIT_WORK(&device->rcu_work, __free_device);
	schedule_work(&device->rcu_work);
}

Y
Yan Zheng 已提交
706
static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
707 708
{
	struct btrfs_device *device;
Y
Yan Zheng 已提交
709

Y
Yan Zheng 已提交
710 711
	if (--fs_devices->opened > 0)
		return 0;
712

713
	mutex_lock(&fs_devices->device_list_mutex);
Q
Qinghuang Feng 已提交
714
	list_for_each_entry(device, &fs_devices->devices, dev_list) {
715
		struct btrfs_device *new_device;
716
		struct rcu_string *name;
717 718

		if (device->bdev)
719
			fs_devices->open_devices--;
720

721 722
		if (device->writeable &&
		    device->devid != BTRFS_DEV_REPLACE_DEVID) {
Y
Yan Zheng 已提交
723 724 725 726
			list_del_init(&device->dev_alloc_list);
			fs_devices->rw_devices--;
		}

727 728
		if (device->missing)
			fs_devices->missing_devices--;
729

730 731 732
		new_device = btrfs_alloc_device(NULL, &device->devid,
						device->uuid);
		BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
733 734

		/* Safe because we are under uuid_mutex */
735 736
		if (device->name) {
			name = rcu_string_strdup(device->name->str, GFP_NOFS);
737
			BUG_ON(!name); /* -ENOMEM */
738 739
			rcu_assign_pointer(new_device->name, name);
		}
740

741
		list_replace_rcu(&device->dev_list, &new_device->dev_list);
742
		new_device->fs_devices = device->fs_devices;
743 744

		call_rcu(&device->rcu, free_device);
745
	}
746 747
	mutex_unlock(&fs_devices->device_list_mutex);

Y
Yan Zheng 已提交
748 749
	WARN_ON(fs_devices->open_devices);
	WARN_ON(fs_devices->rw_devices);
Y
Yan Zheng 已提交
750 751 752
	fs_devices->opened = 0;
	fs_devices->seeding = 0;

753 754 755
	return 0;
}

Y
Yan Zheng 已提交
756 757
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
{
Y
Yan Zheng 已提交
758
	struct btrfs_fs_devices *seed_devices = NULL;
Y
Yan Zheng 已提交
759 760 761 762
	int ret;

	mutex_lock(&uuid_mutex);
	ret = __btrfs_close_devices(fs_devices);
Y
Yan Zheng 已提交
763 764 765 766
	if (!fs_devices->opened) {
		seed_devices = fs_devices->seed;
		fs_devices->seed = NULL;
	}
Y
Yan Zheng 已提交
767
	mutex_unlock(&uuid_mutex);
Y
Yan Zheng 已提交
768 769 770 771 772 773 774

	while (seed_devices) {
		fs_devices = seed_devices;
		seed_devices = fs_devices->seed;
		__btrfs_close_devices(fs_devices);
		free_fs_devices(fs_devices);
	}
775 776 777 778 779 780
	/*
	 * Wait for rcu kworkers under __btrfs_close_devices
	 * to finish all blkdev_puts so device is really
	 * free when umount is done.
	 */
	rcu_barrier();
Y
Yan Zheng 已提交
781 782 783
	return ret;
}

Y
Yan Zheng 已提交
784 785
static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
				fmode_t flags, void *holder)
786
{
787
	struct request_queue *q;
788 789 790
	struct block_device *bdev;
	struct list_head *head = &fs_devices->devices;
	struct btrfs_device *device;
791
	struct btrfs_device *latest_dev = NULL;
792 793 794
	struct buffer_head *bh;
	struct btrfs_super_block *disk_super;
	u64 devid;
Y
Yan Zheng 已提交
795
	int seeding = 1;
796
	int ret = 0;
797

798 799
	flags |= FMODE_EXCL;

Q
Qinghuang Feng 已提交
800
	list_for_each_entry(device, head, dev_list) {
801 802
		if (device->bdev)
			continue;
803 804 805
		if (!device->name)
			continue;

806 807 808
		/* Just open everything we can; ignore failures here */
		if (btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
					    &bdev, &bh))
809
			continue;
810 811

		disk_super = (struct btrfs_super_block *)bh->b_data;
812
		devid = btrfs_stack_device_id(&disk_super->dev_item);
813 814 815
		if (devid != device->devid)
			goto error_brelse;

Y
Yan Zheng 已提交
816 817 818 819 820
		if (memcmp(device->uuid, disk_super->dev_item.uuid,
			   BTRFS_UUID_SIZE))
			goto error_brelse;

		device->generation = btrfs_super_generation(disk_super);
821 822 823
		if (!latest_dev ||
		    device->generation > latest_dev->generation)
			latest_dev = device;
824

Y
Yan Zheng 已提交
825 826 827 828 829 830 831
		if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
			device->writeable = 0;
		} else {
			device->writeable = !bdev_read_only(bdev);
			seeding = 0;
		}

832
		q = bdev_get_queue(bdev);
833
		if (blk_queue_discard(q))
834 835
			device->can_discard = 1;

836
		device->bdev = bdev;
837
		device->in_fs_metadata = 0;
838 839
		device->mode = flags;

C
Chris Mason 已提交
840 841 842
		if (!blk_queue_nonrot(bdev_get_queue(bdev)))
			fs_devices->rotating = 1;

843
		fs_devices->open_devices++;
844 845
		if (device->writeable &&
		    device->devid != BTRFS_DEV_REPLACE_DEVID) {
Y
Yan Zheng 已提交
846 847 848 849
			fs_devices->rw_devices++;
			list_add(&device->dev_alloc_list,
				 &fs_devices->alloc_list);
		}
850
		brelse(bh);
851
		continue;
852

853 854
error_brelse:
		brelse(bh);
855
		blkdev_put(bdev, flags);
856
		continue;
857
	}
858
	if (fs_devices->open_devices == 0) {
859
		ret = -EINVAL;
860 861
		goto out;
	}
Y
Yan Zheng 已提交
862 863
	fs_devices->seeding = seeding;
	fs_devices->opened = 1;
864
	fs_devices->latest_bdev = latest_dev->bdev;
Y
Yan Zheng 已提交
865
	fs_devices->total_rw_bytes = 0;
866
out:
Y
Yan Zheng 已提交
867 868 869 870
	return ret;
}

int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
871
		       fmode_t flags, void *holder)
Y
Yan Zheng 已提交
872 873 874 875 876
{
	int ret;

	mutex_lock(&uuid_mutex);
	if (fs_devices->opened) {
Y
Yan Zheng 已提交
877 878
		fs_devices->opened++;
		ret = 0;
Y
Yan Zheng 已提交
879
	} else {
880
		ret = __btrfs_open_devices(fs_devices, flags, holder);
Y
Yan Zheng 已提交
881
	}
882 883 884 885
	mutex_unlock(&uuid_mutex);
	return ret;
}

886 887 888 889 890
/*
 * Look for a btrfs signature on a device. This may be called out of the mount path
 * and we are not allowed to call set_blocksize during the scan. The superblock
 * is read via pagecache
 */
891
int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
892 893 894 895
			  struct btrfs_fs_devices **fs_devices_ret)
{
	struct btrfs_super_block *disk_super;
	struct block_device *bdev;
896 897 898
	struct page *page;
	void *p;
	int ret = -EINVAL;
899
	u64 devid;
900
	u64 transid;
J
Josef Bacik 已提交
901
	u64 total_devices;
902 903
	u64 bytenr;
	pgoff_t index;
904

905 906 907 908 909 910 911
	/*
	 * we would like to check all the supers, but that would make
	 * a btrfs mount succeed after a mkfs from a different FS.
	 * So, we need to add a special mount option to scan for
	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
	 */
	bytenr = btrfs_sb_offset(0);
912
	flags |= FMODE_EXCL;
913
	mutex_lock(&uuid_mutex);
914 915 916 917 918

	bdev = blkdev_get_by_path(path, flags, holder);

	if (IS_ERR(bdev)) {
		ret = PTR_ERR(bdev);
919
		goto error;
920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947
	}

	/* make sure our super fits in the device */
	if (bytenr + PAGE_CACHE_SIZE >= i_size_read(bdev->bd_inode))
		goto error_bdev_put;

	/* make sure our super fits in the page */
	if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
		goto error_bdev_put;

	/* make sure our super doesn't straddle pages on disk */
	index = bytenr >> PAGE_CACHE_SHIFT;
	if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_CACHE_SHIFT != index)
		goto error_bdev_put;

	/* pull in the page with our super */
	page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
				   index, GFP_NOFS);

	if (IS_ERR_OR_NULL(page))
		goto error_bdev_put;

	p = kmap(page);

	/* align our pointer to the offset of the super block */
	disk_super = p + (bytenr & ~PAGE_CACHE_MASK);

	if (btrfs_super_bytenr(disk_super) != bytenr ||
948
	    btrfs_super_magic(disk_super) != BTRFS_MAGIC)
949 950
		goto error_unmap;

951
	devid = btrfs_stack_device_id(&disk_super->dev_item);
952
	transid = btrfs_super_generation(disk_super);
J
Josef Bacik 已提交
953
	total_devices = btrfs_super_num_devices(disk_super);
954

955
	ret = device_list_add(path, disk_super, devid, fs_devices_ret);
956 957 958 959 960 961 962 963 964 965 966 967
	if (ret > 0) {
		if (disk_super->label[0]) {
			if (disk_super->label[BTRFS_LABEL_SIZE - 1])
				disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
			printk(KERN_INFO "BTRFS: device label %s ", disk_super->label);
		} else {
			printk(KERN_INFO "BTRFS: device fsid %pU ", disk_super->fsid);
		}

		printk(KERN_CONT "devid %llu transid %llu %s\n", devid, transid, path);
		ret = 0;
	}
J
Josef Bacik 已提交
968 969
	if (!ret && fs_devices_ret)
		(*fs_devices_ret)->total_devices = total_devices;
970 971 972 973 974 975

error_unmap:
	kunmap(page);
	page_cache_release(page);

error_bdev_put:
976
	blkdev_put(bdev, flags);
977
error:
978
	mutex_unlock(&uuid_mutex);
979 980
	return ret;
}
981

982 983 984 985 986 987 988 989 990 991 992 993 994 995 996
/* helper to account the used device space in the range */
int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
				   u64 end, u64 *length)
{
	struct btrfs_key key;
	struct btrfs_root *root = device->dev_root;
	struct btrfs_dev_extent *dev_extent;
	struct btrfs_path *path;
	u64 extent_end;
	int ret;
	int slot;
	struct extent_buffer *l;

	*length = 0;

997
	if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037
		return 0;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
	path->reada = 2;

	key.objectid = device->devid;
	key.offset = start;
	key.type = BTRFS_DEV_EXTENT_KEY;

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
	if (ret > 0) {
		ret = btrfs_previous_item(root, path, key.objectid, key.type);
		if (ret < 0)
			goto out;
	}

	while (1) {
		l = path->nodes[0];
		slot = path->slots[0];
		if (slot >= btrfs_header_nritems(l)) {
			ret = btrfs_next_leaf(root, path);
			if (ret == 0)
				continue;
			if (ret < 0)
				goto out;

			break;
		}
		btrfs_item_key_to_cpu(l, &key, slot);

		if (key.objectid < device->devid)
			goto next;

		if (key.objectid > device->devid)
			break;

1038
		if (key.type != BTRFS_DEV_EXTENT_KEY)
1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
			goto next;

		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
		extent_end = key.offset + btrfs_dev_extent_length(l,
								  dev_extent);
		if (key.offset <= start && extent_end > end) {
			*length = end - start + 1;
			break;
		} else if (key.offset <= start && extent_end > start)
			*length += extent_end - start;
		else if (key.offset > start && extent_end <= end)
			*length += extent_end - key.offset;
		else if (key.offset > start && key.offset <= end) {
			*length += end - key.offset + 1;
			break;
		} else if (key.offset > end)
			break;

next:
		path->slots[0]++;
	}
	ret = 0;
out:
	btrfs_free_path(path);
	return ret;
}

1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094
static int contains_pending_extent(struct btrfs_trans_handle *trans,
				   struct btrfs_device *device,
				   u64 *start, u64 len)
{
	struct extent_map *em;
	int ret = 0;

	list_for_each_entry(em, &trans->transaction->pending_chunks, list) {
		struct map_lookup *map;
		int i;

		map = (struct map_lookup *)em->bdev;
		for (i = 0; i < map->num_stripes; i++) {
			if (map->stripes[i].dev != device)
				continue;
			if (map->stripes[i].physical >= *start + len ||
			    map->stripes[i].physical + em->orig_block_len <=
			    *start)
				continue;
			*start = map->stripes[i].physical +
				em->orig_block_len;
			ret = 1;
		}
	}

	return ret;
}


1095
/*
1096 1097 1098 1099 1100 1101 1102
 * find_free_dev_extent - find free space in the specified device
 * @device:	the device which we search the free space in
 * @num_bytes:	the size of the free space that we need
 * @start:	store the start of the free space.
 * @len:	the size of the free space. that we find, or the size of the max
 * 		free space if we don't find suitable free space
 *
1103 1104 1105
 * this uses a pretty simple search, the expectation is that it is
 * called very infrequently and that a given device has a small number
 * of extents
1106 1107 1108 1109 1110 1111 1112 1113
 *
 * @start is used to store the start of the free space if we find. But if we
 * don't find suitable free space, it will be used to store the start position
 * of the max free space.
 *
 * @len is used to store the size of the free space that we find.
 * But if we don't find suitable free space, it is used to store the size of
 * the max free space.
1114
 */
1115 1116
int find_free_dev_extent(struct btrfs_trans_handle *trans,
			 struct btrfs_device *device, u64 num_bytes,
1117
			 u64 *start, u64 *len)
1118 1119 1120
{
	struct btrfs_key key;
	struct btrfs_root *root = device->dev_root;
1121
	struct btrfs_dev_extent *dev_extent;
Y
Yan Zheng 已提交
1122
	struct btrfs_path *path;
1123 1124 1125 1126 1127
	u64 hole_size;
	u64 max_hole_start;
	u64 max_hole_size;
	u64 extent_end;
	u64 search_start;
1128 1129
	u64 search_end = device->total_bytes;
	int ret;
1130
	int slot;
1131 1132 1133 1134
	struct extent_buffer *l;

	/* FIXME use last free of some kind */

1135 1136 1137
	/* we don't want to overwrite the superblock on the drive,
	 * so we make sure to start at an offset of at least 1MB
	 */
A
Arne Jansen 已提交
1138
	search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
1139

1140 1141 1142 1143
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
again:
1144 1145
	max_hole_start = search_start;
	max_hole_size = 0;
1146
	hole_size = 0;
1147

1148
	if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
1149
		ret = -ENOSPC;
1150
		goto out;
1151 1152 1153
	}

	path->reada = 2;
1154 1155
	path->search_commit_root = 1;
	path->skip_locking = 1;
1156

1157 1158 1159
	key.objectid = device->devid;
	key.offset = search_start;
	key.type = BTRFS_DEV_EXTENT_KEY;
1160

1161
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1162
	if (ret < 0)
1163
		goto out;
1164 1165 1166
	if (ret > 0) {
		ret = btrfs_previous_item(root, path, key.objectid, key.type);
		if (ret < 0)
1167
			goto out;
1168
	}
1169

1170 1171 1172 1173 1174 1175 1176 1177
	while (1) {
		l = path->nodes[0];
		slot = path->slots[0];
		if (slot >= btrfs_header_nritems(l)) {
			ret = btrfs_next_leaf(root, path);
			if (ret == 0)
				continue;
			if (ret < 0)
1178 1179 1180
				goto out;

			break;
1181 1182 1183 1184 1185 1186 1187
		}
		btrfs_item_key_to_cpu(l, &key, slot);

		if (key.objectid < device->devid)
			goto next;

		if (key.objectid > device->devid)
1188
			break;
1189

1190
		if (key.type != BTRFS_DEV_EXTENT_KEY)
1191
			goto next;
1192

1193 1194
		if (key.offset > search_start) {
			hole_size = key.offset - search_start;
1195

1196 1197 1198 1199 1200 1201 1202 1203 1204
			/*
			 * Have to check before we set max_hole_start, otherwise
			 * we could end up sending back this offset anyway.
			 */
			if (contains_pending_extent(trans, device,
						    &search_start,
						    hole_size))
				hole_size = 0;

1205 1206 1207 1208
			if (hole_size > max_hole_size) {
				max_hole_start = search_start;
				max_hole_size = hole_size;
			}
1209

1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221
			/*
			 * If this free space is greater than which we need,
			 * it must be the max free space that we have found
			 * until now, so max_hole_start must point to the start
			 * of this free space and the length of this free space
			 * is stored in max_hole_size. Thus, we return
			 * max_hole_start and max_hole_size and go back to the
			 * caller.
			 */
			if (hole_size >= num_bytes) {
				ret = 0;
				goto out;
1222 1223 1224 1225
			}
		}

		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1226 1227 1228 1229
		extent_end = key.offset + btrfs_dev_extent_length(l,
								  dev_extent);
		if (extent_end > search_start)
			search_start = extent_end;
1230 1231 1232 1233 1234
next:
		path->slots[0]++;
		cond_resched();
	}

1235 1236 1237 1238 1239 1240 1241 1242
	/*
	 * At this point, search_start should be the end of
	 * allocated dev extents, and when shrinking the device,
	 * search_end may be smaller than search_start.
	 */
	if (search_end > search_start)
		hole_size = search_end - search_start;

1243 1244 1245
	if (hole_size > max_hole_size) {
		max_hole_start = search_start;
		max_hole_size = hole_size;
1246 1247
	}

1248 1249 1250 1251 1252
	if (contains_pending_extent(trans, device, &search_start, hole_size)) {
		btrfs_release_path(path);
		goto again;
	}

1253 1254 1255 1256 1257 1258 1259
	/* See above. */
	if (hole_size < num_bytes)
		ret = -ENOSPC;
	else
		ret = 0;

out:
Y
Yan Zheng 已提交
1260
	btrfs_free_path(path);
1261
	*start = max_hole_start;
1262
	if (len)
1263
		*len = max_hole_size;
1264 1265 1266
	return ret;
}

1267
static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1268
			  struct btrfs_device *device,
M
Miao Xie 已提交
1269
			  u64 start, u64 *dev_extent_len)
1270 1271 1272 1273 1274
{
	int ret;
	struct btrfs_path *path;
	struct btrfs_root *root = device->dev_root;
	struct btrfs_key key;
1275 1276 1277
	struct btrfs_key found_key;
	struct extent_buffer *leaf = NULL;
	struct btrfs_dev_extent *extent = NULL;
1278 1279 1280 1281 1282 1283 1284 1285

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = device->devid;
	key.offset = start;
	key.type = BTRFS_DEV_EXTENT_KEY;
M
Miao Xie 已提交
1286
again:
1287
	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1288 1289 1290
	if (ret > 0) {
		ret = btrfs_previous_item(root, path, key.objectid,
					  BTRFS_DEV_EXTENT_KEY);
1291 1292
		if (ret)
			goto out;
1293 1294 1295 1296 1297 1298
		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
		extent = btrfs_item_ptr(leaf, path->slots[0],
					struct btrfs_dev_extent);
		BUG_ON(found_key.offset > start || found_key.offset +
		       btrfs_dev_extent_length(leaf, extent) < start);
M
Miao Xie 已提交
1299 1300 1301
		key = found_key;
		btrfs_release_path(path);
		goto again;
1302 1303 1304 1305
	} else if (ret == 0) {
		leaf = path->nodes[0];
		extent = btrfs_item_ptr(leaf, path->slots[0],
					struct btrfs_dev_extent);
1306 1307 1308
	} else {
		btrfs_error(root->fs_info, ret, "Slot search failed");
		goto out;
1309
	}
1310

M
Miao Xie 已提交
1311 1312
	*dev_extent_len = btrfs_dev_extent_length(leaf, extent);

1313
	ret = btrfs_del_item(trans, root, path);
1314 1315 1316 1317
	if (ret) {
		btrfs_error(root->fs_info, ret,
			    "Failed to remove dev extent item");
	}
1318
out:
1319 1320 1321 1322
	btrfs_free_path(path);
	return ret;
}

1323 1324 1325 1326
static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
				  struct btrfs_device *device,
				  u64 chunk_tree, u64 chunk_objectid,
				  u64 chunk_offset, u64 start, u64 num_bytes)
1327 1328 1329 1330 1331 1332 1333 1334
{
	int ret;
	struct btrfs_path *path;
	struct btrfs_root *root = device->dev_root;
	struct btrfs_dev_extent *extent;
	struct extent_buffer *leaf;
	struct btrfs_key key;

1335
	WARN_ON(!device->in_fs_metadata);
1336
	WARN_ON(device->is_tgtdev_for_dev_replace);
1337 1338 1339 1340 1341
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = device->devid;
Y
Yan Zheng 已提交
1342
	key.offset = start;
1343 1344 1345
	key.type = BTRFS_DEV_EXTENT_KEY;
	ret = btrfs_insert_empty_item(trans, root, path, &key,
				      sizeof(*extent));
1346 1347
	if (ret)
		goto out;
1348 1349 1350 1351

	leaf = path->nodes[0];
	extent = btrfs_item_ptr(leaf, path->slots[0],
				struct btrfs_dev_extent);
1352 1353 1354 1355 1356
	btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
	btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
	btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);

	write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1357
		    btrfs_dev_extent_chunk_tree_uuid(extent), BTRFS_UUID_SIZE);
1358

1359 1360
	btrfs_set_dev_extent_length(leaf, extent, num_bytes);
	btrfs_mark_buffer_dirty(leaf);
1361
out:
1362 1363 1364 1365
	btrfs_free_path(path);
	return ret;
}

1366
static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
1367
{
1368 1369 1370 1371
	struct extent_map_tree *em_tree;
	struct extent_map *em;
	struct rb_node *n;
	u64 ret = 0;
1372

1373 1374 1375 1376 1377 1378
	em_tree = &fs_info->mapping_tree.map_tree;
	read_lock(&em_tree->lock);
	n = rb_last(&em_tree->map);
	if (n) {
		em = rb_entry(n, struct extent_map, rb_node);
		ret = em->start + em->len;
1379
	}
1380 1381
	read_unlock(&em_tree->lock);

1382 1383 1384
	return ret;
}

1385 1386
static noinline int find_next_devid(struct btrfs_fs_info *fs_info,
				    u64 *devid_ret)
1387 1388 1389 1390
{
	int ret;
	struct btrfs_key key;
	struct btrfs_key found_key;
Y
Yan Zheng 已提交
1391 1392 1393 1394 1395
	struct btrfs_path *path;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;
1396 1397 1398 1399 1400

	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.type = BTRFS_DEV_ITEM_KEY;
	key.offset = (u64)-1;

1401
	ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0);
1402 1403 1404
	if (ret < 0)
		goto error;

1405
	BUG_ON(ret == 0); /* Corruption */
1406

1407 1408
	ret = btrfs_previous_item(fs_info->chunk_root, path,
				  BTRFS_DEV_ITEMS_OBJECTID,
1409 1410
				  BTRFS_DEV_ITEM_KEY);
	if (ret) {
1411
		*devid_ret = 1;
1412 1413 1414
	} else {
		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
				      path->slots[0]);
1415
		*devid_ret = found_key.offset + 1;
1416 1417 1418
	}
	ret = 0;
error:
Y
Yan Zheng 已提交
1419
	btrfs_free_path(path);
1420 1421 1422 1423 1424 1425 1426
	return ret;
}

/*
 * the device information is stored in the chunk root
 * the btrfs_device struct should be fully filled in
 */
1427 1428 1429
static int btrfs_add_device(struct btrfs_trans_handle *trans,
			    struct btrfs_root *root,
			    struct btrfs_device *device)
1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445
{
	int ret;
	struct btrfs_path *path;
	struct btrfs_dev_item *dev_item;
	struct extent_buffer *leaf;
	struct btrfs_key key;
	unsigned long ptr;

	root = root->fs_info->chunk_root;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.type = BTRFS_DEV_ITEM_KEY;
Y
Yan Zheng 已提交
1446
	key.offset = device->devid;
1447 1448

	ret = btrfs_insert_empty_item(trans, root, path, &key,
1449
				      sizeof(*dev_item));
1450 1451 1452 1453 1454 1455 1456
	if (ret)
		goto out;

	leaf = path->nodes[0];
	dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);

	btrfs_set_device_id(leaf, dev_item, device->devid);
Y
Yan Zheng 已提交
1457
	btrfs_set_device_generation(leaf, dev_item, 0);
1458 1459 1460 1461
	btrfs_set_device_type(leaf, dev_item, device->type);
	btrfs_set_device_io_align(leaf, dev_item, device->io_align);
	btrfs_set_device_io_width(leaf, dev_item, device->io_width);
	btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1462 1463 1464 1465
	btrfs_set_device_total_bytes(leaf, dev_item,
				     btrfs_device_get_disk_total_bytes(device));
	btrfs_set_device_bytes_used(leaf, dev_item,
				    btrfs_device_get_bytes_used(device));
1466 1467 1468
	btrfs_set_device_group(leaf, dev_item, 0);
	btrfs_set_device_seek_speed(leaf, dev_item, 0);
	btrfs_set_device_bandwidth(leaf, dev_item, 0);
1469
	btrfs_set_device_start_offset(leaf, dev_item, 0);
1470

1471
	ptr = btrfs_device_uuid(dev_item);
1472
	write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1473
	ptr = btrfs_device_fsid(dev_item);
Y
Yan Zheng 已提交
1474
	write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1475 1476
	btrfs_mark_buffer_dirty(leaf);

Y
Yan Zheng 已提交
1477
	ret = 0;
1478 1479 1480 1481
out:
	btrfs_free_path(path);
	return ret;
}
1482

1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498
/*
 * Function to update ctime/mtime for a given device path.
 * Mainly used for ctime/mtime based probe like libblkid.
 */
static void update_dev_time(char *path_name)
{
	struct file *filp;

	filp = filp_open(path_name, O_RDWR, 0);
	if (!filp)
		return;
	file_update_time(filp);
	filp_close(filp, NULL);
	return;
}

1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512
static int btrfs_rm_dev_item(struct btrfs_root *root,
			     struct btrfs_device *device)
{
	int ret;
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_trans_handle *trans;

	root = root->fs_info->chunk_root;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

1513
	trans = btrfs_start_transaction(root, 0);
1514 1515 1516 1517
	if (IS_ERR(trans)) {
		btrfs_free_path(path);
		return PTR_ERR(trans);
	}
1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542
	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.type = BTRFS_DEV_ITEM_KEY;
	key.offset = device->devid;

	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	if (ret < 0)
		goto out;

	if (ret > 0) {
		ret = -ENOENT;
		goto out;
	}

	ret = btrfs_del_item(trans, root, path);
	if (ret)
		goto out;
out:
	btrfs_free_path(path);
	btrfs_commit_transaction(trans, root);
	return ret;
}

int btrfs_rm_device(struct btrfs_root *root, char *device_path)
{
	struct btrfs_device *device;
Y
Yan Zheng 已提交
1543
	struct btrfs_device *next_device;
1544
	struct block_device *bdev;
1545
	struct buffer_head *bh = NULL;
1546
	struct btrfs_super_block *disk_super;
1547
	struct btrfs_fs_devices *cur_devices;
1548 1549
	u64 all_avail;
	u64 devid;
Y
Yan Zheng 已提交
1550 1551
	u64 num_devices;
	u8 *dev_uuid;
1552
	unsigned seq;
1553
	int ret = 0;
1554
	bool clear_super = false;
1555 1556 1557

	mutex_lock(&uuid_mutex);

1558 1559 1560 1561 1562 1563 1564
	do {
		seq = read_seqbegin(&root->fs_info->profiles_lock);

		all_avail = root->fs_info->avail_data_alloc_bits |
			    root->fs_info->avail_system_alloc_bits |
			    root->fs_info->avail_metadata_alloc_bits;
	} while (read_seqretry(&root->fs_info->profiles_lock, seq));
1565

1566 1567 1568 1569 1570 1571 1572 1573 1574
	num_devices = root->fs_info->fs_devices->num_devices;
	btrfs_dev_replace_lock(&root->fs_info->dev_replace);
	if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
		WARN_ON(num_devices < 1);
		num_devices--;
	}
	btrfs_dev_replace_unlock(&root->fs_info->dev_replace);

	if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1575
		ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
1576 1577 1578
		goto out;
	}

1579
	if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1580
		ret = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
1581 1582 1583
		goto out;
	}

D
David Woodhouse 已提交
1584 1585
	if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
	    root->fs_info->fs_devices->rw_devices <= 2) {
1586
		ret = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
D
David Woodhouse 已提交
1587 1588 1589 1590
		goto out;
	}
	if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
	    root->fs_info->fs_devices->rw_devices <= 3) {
1591
		ret = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
D
David Woodhouse 已提交
1592 1593 1594
		goto out;
	}

1595 1596 1597
	if (strcmp(device_path, "missing") == 0) {
		struct list_head *devices;
		struct btrfs_device *tmp;
1598

1599 1600
		device = NULL;
		devices = &root->fs_info->fs_devices->devices;
1601 1602 1603 1604
		/*
		 * It is safe to read the devices since the volume_mutex
		 * is held.
		 */
Q
Qinghuang Feng 已提交
1605
		list_for_each_entry(tmp, devices, dev_list) {
1606 1607 1608
			if (tmp->in_fs_metadata &&
			    !tmp->is_tgtdev_for_dev_replace &&
			    !tmp->bdev) {
1609 1610 1611 1612 1613 1614 1615 1616
				device = tmp;
				break;
			}
		}
		bdev = NULL;
		bh = NULL;
		disk_super = NULL;
		if (!device) {
1617
			ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
1618 1619 1620
			goto out;
		}
	} else {
1621
		ret = btrfs_get_bdev_and_sb(device_path,
1622
					    FMODE_WRITE | FMODE_EXCL,
1623 1624 1625
					    root->fs_info->bdev_holder, 0,
					    &bdev, &bh);
		if (ret)
1626 1627
			goto out;
		disk_super = (struct btrfs_super_block *)bh->b_data;
1628
		devid = btrfs_stack_device_id(&disk_super->dev_item);
Y
Yan Zheng 已提交
1629
		dev_uuid = disk_super->dev_item.uuid;
1630
		device = btrfs_find_device(root->fs_info, devid, dev_uuid,
Y
Yan Zheng 已提交
1631
					   disk_super->fsid);
1632 1633 1634 1635
		if (!device) {
			ret = -ENOENT;
			goto error_brelse;
		}
Y
Yan Zheng 已提交
1636
	}
1637

1638
	if (device->is_tgtdev_for_dev_replace) {
1639
		ret = BTRFS_ERROR_DEV_TGT_REPLACE;
1640 1641 1642
		goto error_brelse;
	}

Y
Yan Zheng 已提交
1643
	if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1644
		ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
Y
Yan Zheng 已提交
1645 1646 1647 1648
		goto error_brelse;
	}

	if (device->writeable) {
1649
		lock_chunks(root);
Y
Yan Zheng 已提交
1650
		list_del_init(&device->dev_alloc_list);
1651
		device->fs_devices->rw_devices--;
1652
		unlock_chunks(root);
1653
		clear_super = true;
1654
	}
1655

1656
	mutex_unlock(&uuid_mutex);
1657
	ret = btrfs_shrink_device(device, 0);
1658
	mutex_lock(&uuid_mutex);
1659
	if (ret)
1660
		goto error_undo;
1661

1662 1663 1664 1665 1666
	/*
	 * TODO: the superblock still includes this device in its num_devices
	 * counter although write_all_supers() is not locked out. This
	 * could give a filesystem state which requires a degraded mount.
	 */
1667 1668
	ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
	if (ret)
1669
		goto error_undo;
1670

Y
Yan Zheng 已提交
1671
	device->in_fs_metadata = 0;
1672
	btrfs_scrub_cancel_dev(root->fs_info, device);
1673 1674 1675 1676

	/*
	 * the device list mutex makes sure that we don't change
	 * the device list while someone else is writing out all
1677 1678 1679 1680 1681
	 * the device supers. Whoever is writing all supers, should
	 * lock the device list mutex before getting the number of
	 * devices in the super block (super_copy). Conversely,
	 * whoever updates the number of devices in the super block
	 * (super_copy) should hold the device list mutex.
1682
	 */
1683 1684

	cur_devices = device->fs_devices;
1685
	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1686
	list_del_rcu(&device->dev_list);
1687

Y
Yan Zheng 已提交
1688
	device->fs_devices->num_devices--;
J
Josef Bacik 已提交
1689
	device->fs_devices->total_devices--;
Y
Yan Zheng 已提交
1690

1691
	if (device->missing)
1692
		device->fs_devices->missing_devices--;
1693

Y
Yan Zheng 已提交
1694 1695 1696 1697 1698 1699 1700
	next_device = list_entry(root->fs_info->fs_devices->devices.next,
				 struct btrfs_device, dev_list);
	if (device->bdev == root->fs_info->sb->s_bdev)
		root->fs_info->sb->s_bdev = next_device->bdev;
	if (device->bdev == root->fs_info->fs_devices->latest_bdev)
		root->fs_info->fs_devices->latest_bdev = next_device->bdev;

1701
	if (device->bdev) {
Y
Yan Zheng 已提交
1702
		device->fs_devices->open_devices--;
1703 1704 1705
		/* remove sysfs entry */
		btrfs_kobj_rm_device(root->fs_info, device);
	}
1706

1707
	call_rcu(&device->rcu, free_device);
Y
Yan Zheng 已提交
1708

1709 1710
	num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
	btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1711
	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
Y
Yan Zheng 已提交
1712

1713
	if (cur_devices->open_devices == 0) {
Y
Yan Zheng 已提交
1714 1715 1716
		struct btrfs_fs_devices *fs_devices;
		fs_devices = root->fs_info->fs_devices;
		while (fs_devices) {
1717 1718
			if (fs_devices->seed == cur_devices) {
				fs_devices->seed = cur_devices->seed;
Y
Yan Zheng 已提交
1719
				break;
1720
			}
Y
Yan Zheng 已提交
1721
			fs_devices = fs_devices->seed;
Y
Yan Zheng 已提交
1722
		}
1723 1724 1725
		cur_devices->seed = NULL;
		__btrfs_close_devices(cur_devices);
		free_fs_devices(cur_devices);
Y
Yan Zheng 已提交
1726 1727
	}

1728 1729 1730
	root->fs_info->num_tolerated_disk_barrier_failures =
		btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);

Y
Yan Zheng 已提交
1731 1732 1733 1734
	/*
	 * at this point, the device is zero sized.  We want to
	 * remove it from the devices list and zero out the old super
	 */
1735
	if (clear_super && disk_super) {
1736 1737 1738
		u64 bytenr;
		int i;

1739 1740 1741 1742 1743 1744
		/* make sure this device isn't detected as part of
		 * the FS anymore
		 */
		memset(&disk_super->magic, 0, sizeof(disk_super->magic));
		set_buffer_dirty(bh);
		sync_dirty_buffer(bh);
1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772

		/* clear the mirror copies of super block on the disk
		 * being removed, 0th copy is been taken care above and
		 * the below would take of the rest
		 */
		for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) {
			bytenr = btrfs_sb_offset(i);
			if (bytenr + BTRFS_SUPER_INFO_SIZE >=
					i_size_read(bdev->bd_inode))
				break;

			brelse(bh);
			bh = __bread(bdev, bytenr / 4096,
					BTRFS_SUPER_INFO_SIZE);
			if (!bh)
				continue;

			disk_super = (struct btrfs_super_block *)bh->b_data;

			if (btrfs_super_bytenr(disk_super) != bytenr ||
				btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
				continue;
			}
			memset(&disk_super->magic, 0,
						sizeof(disk_super->magic));
			set_buffer_dirty(bh);
			sync_dirty_buffer(bh);
		}
1773
	}
1774 1775 1776

	ret = 0;

1777 1778
	if (bdev) {
		/* Notify udev that device has changed */
1779
		btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1780

1781 1782 1783 1784
		/* Update ctime/mtime for device path for libblkid */
		update_dev_time(device_path);
	}

1785 1786
error_brelse:
	brelse(bh);
1787
	if (bdev)
1788
		blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1789 1790 1791
out:
	mutex_unlock(&uuid_mutex);
	return ret;
1792 1793
error_undo:
	if (device->writeable) {
1794
		lock_chunks(root);
1795 1796
		list_add(&device->dev_alloc_list,
			 &root->fs_info->fs_devices->alloc_list);
1797
		device->fs_devices->rw_devices++;
1798
		unlock_chunks(root);
1799 1800
	}
	goto error_brelse;
1801 1802
}

1803 1804 1805
void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
				 struct btrfs_device *srcdev)
{
1806 1807
	struct btrfs_fs_devices *fs_devices;

1808
	WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1809

1810 1811 1812 1813 1814 1815 1816
	/*
	 * in case of fs with no seed, srcdev->fs_devices will point
	 * to fs_devices of fs_info. However when the dev being replaced is
	 * a seed dev it will point to the seed's local fs_devices. In short
	 * srcdev will have its correct fs_devices in both the cases.
	 */
	fs_devices = srcdev->fs_devices;
1817

1818 1819
	list_del_rcu(&srcdev->dev_list);
	list_del_rcu(&srcdev->dev_alloc_list);
1820
	fs_devices->num_devices--;
1821
	if (srcdev->missing)
1822
		fs_devices->missing_devices--;
1823

1824 1825 1826 1827
	if (srcdev->writeable) {
		fs_devices->rw_devices--;
		/* zero out the old super if it is writable */
		btrfs_scratch_superblock(srcdev);
1828 1829
	}

1830
	if (srcdev->bdev)
1831
		fs_devices->open_devices--;
1832 1833

	call_rcu(&srcdev->rcu, free_device);
1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853

	/*
	 * unless fs_devices is seed fs, num_devices shouldn't go
	 * zero
	 */
	BUG_ON(!fs_devices->num_devices && !fs_devices->seeding);

	/* if this is no devs we rather delete the fs_devices */
	if (!fs_devices->num_devices) {
		struct btrfs_fs_devices *tmp_fs_devices;

		tmp_fs_devices = fs_info->fs_devices;
		while (tmp_fs_devices) {
			if (tmp_fs_devices->seed == fs_devices) {
				tmp_fs_devices->seed = fs_devices->seed;
				break;
			}
			tmp_fs_devices = tmp_fs_devices->seed;
		}
		fs_devices->seed = NULL;
1854 1855
		__btrfs_close_devices(fs_devices);
		free_fs_devices(fs_devices);
1856
	}
1857 1858 1859 1860 1861 1862 1863
}

void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
				      struct btrfs_device *tgtdev)
{
	struct btrfs_device *next_device;

1864
	mutex_lock(&uuid_mutex);
1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883
	WARN_ON(!tgtdev);
	mutex_lock(&fs_info->fs_devices->device_list_mutex);
	if (tgtdev->bdev) {
		btrfs_scratch_superblock(tgtdev);
		fs_info->fs_devices->open_devices--;
	}
	fs_info->fs_devices->num_devices--;

	next_device = list_entry(fs_info->fs_devices->devices.next,
				 struct btrfs_device, dev_list);
	if (tgtdev->bdev == fs_info->sb->s_bdev)
		fs_info->sb->s_bdev = next_device->bdev;
	if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
		fs_info->fs_devices->latest_bdev = next_device->bdev;
	list_del_rcu(&tgtdev->dev_list);

	call_rcu(&tgtdev->rcu, free_device);

	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1884
	mutex_unlock(&uuid_mutex);
1885 1886
}

1887 1888
static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
				     struct btrfs_device **device)
1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904
{
	int ret = 0;
	struct btrfs_super_block *disk_super;
	u64 devid;
	u8 *dev_uuid;
	struct block_device *bdev;
	struct buffer_head *bh;

	*device = NULL;
	ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
				    root->fs_info->bdev_holder, 0, &bdev, &bh);
	if (ret)
		return ret;
	disk_super = (struct btrfs_super_block *)bh->b_data;
	devid = btrfs_stack_device_id(&disk_super->dev_item);
	dev_uuid = disk_super->dev_item.uuid;
1905
	*device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
				    disk_super->fsid);
	brelse(bh);
	if (!*device)
		ret = -ENOENT;
	blkdev_put(bdev, FMODE_READ);
	return ret;
}

int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
					 char *device_path,
					 struct btrfs_device **device)
{
	*device = NULL;
	if (strcmp(device_path, "missing") == 0) {
		struct list_head *devices;
		struct btrfs_device *tmp;

		devices = &root->fs_info->fs_devices->devices;
		/*
		 * It is safe to read the devices since the volume_mutex
		 * is held by the caller.
		 */
		list_for_each_entry(tmp, devices, dev_list) {
			if (tmp->in_fs_metadata && !tmp->bdev) {
				*device = tmp;
				break;
			}
		}

		if (!*device) {
1936
			btrfs_err(root->fs_info, "no missing device found");
1937 1938 1939 1940 1941 1942 1943 1944 1945
			return -ENOENT;
		}

		return 0;
	} else {
		return btrfs_find_device_by_path(root, device_path, device);
	}
}

Y
Yan Zheng 已提交
1946 1947 1948
/*
 * does all the dirty work required for changing file system's UUID.
 */
1949
static int btrfs_prepare_sprout(struct btrfs_root *root)
Y
Yan Zheng 已提交
1950 1951 1952
{
	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
	struct btrfs_fs_devices *old_devices;
Y
Yan Zheng 已提交
1953
	struct btrfs_fs_devices *seed_devices;
1954
	struct btrfs_super_block *disk_super = root->fs_info->super_copy;
Y
Yan Zheng 已提交
1955 1956 1957 1958
	struct btrfs_device *device;
	u64 super_flags;

	BUG_ON(!mutex_is_locked(&uuid_mutex));
Y
Yan Zheng 已提交
1959
	if (!fs_devices->seeding)
Y
Yan Zheng 已提交
1960 1961
		return -EINVAL;

1962 1963 1964
	seed_devices = __alloc_fs_devices();
	if (IS_ERR(seed_devices))
		return PTR_ERR(seed_devices);
Y
Yan Zheng 已提交
1965

Y
Yan Zheng 已提交
1966 1967 1968 1969
	old_devices = clone_fs_devices(fs_devices);
	if (IS_ERR(old_devices)) {
		kfree(seed_devices);
		return PTR_ERR(old_devices);
Y
Yan Zheng 已提交
1970
	}
Y
Yan Zheng 已提交
1971

Y
Yan Zheng 已提交
1972 1973
	list_add(&old_devices->list, &fs_uuids);

Y
Yan Zheng 已提交
1974 1975 1976 1977
	memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
	seed_devices->opened = 1;
	INIT_LIST_HEAD(&seed_devices->devices);
	INIT_LIST_HEAD(&seed_devices->alloc_list);
1978
	mutex_init(&seed_devices->device_list_mutex);
1979 1980

	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1981 1982
	list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
			      synchronize_rcu);
M
Miao Xie 已提交
1983 1984
	list_for_each_entry(device, &seed_devices->devices, dev_list)
		device->fs_devices = seed_devices;
1985

M
Miao Xie 已提交
1986
	lock_chunks(root);
Y
Yan Zheng 已提交
1987
	list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
M
Miao Xie 已提交
1988
	unlock_chunks(root);
Y
Yan Zheng 已提交
1989

Y
Yan Zheng 已提交
1990 1991 1992
	fs_devices->seeding = 0;
	fs_devices->num_devices = 0;
	fs_devices->open_devices = 0;
1993 1994
	fs_devices->missing_devices = 0;
	fs_devices->rotating = 0;
Y
Yan Zheng 已提交
1995
	fs_devices->seed = seed_devices;
Y
Yan Zheng 已提交
1996 1997 1998 1999

	generate_random_uuid(fs_devices->fsid);
	memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
	memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
2000 2001
	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);

Y
Yan Zheng 已提交
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048
	super_flags = btrfs_super_flags(disk_super) &
		      ~BTRFS_SUPER_FLAG_SEEDING;
	btrfs_set_super_flags(disk_super, super_flags);

	return 0;
}

/*
 * strore the expected generation for seed devices in device items.
 */
static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
			       struct btrfs_root *root)
{
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_dev_item *dev_item;
	struct btrfs_device *device;
	struct btrfs_key key;
	u8 fs_uuid[BTRFS_UUID_SIZE];
	u8 dev_uuid[BTRFS_UUID_SIZE];
	u64 devid;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	root = root->fs_info->chunk_root;
	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.offset = 0;
	key.type = BTRFS_DEV_ITEM_KEY;

	while (1) {
		ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
		if (ret < 0)
			goto error;

		leaf = path->nodes[0];
next_slot:
		if (path->slots[0] >= btrfs_header_nritems(leaf)) {
			ret = btrfs_next_leaf(root, path);
			if (ret > 0)
				break;
			if (ret < 0)
				goto error;
			leaf = path->nodes[0];
			btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2049
			btrfs_release_path(path);
Y
Yan Zheng 已提交
2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060
			continue;
		}

		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
		if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
		    key.type != BTRFS_DEV_ITEM_KEY)
			break;

		dev_item = btrfs_item_ptr(leaf, path->slots[0],
					  struct btrfs_dev_item);
		devid = btrfs_device_id(leaf, dev_item);
2061
		read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
Y
Yan Zheng 已提交
2062
				   BTRFS_UUID_SIZE);
2063
		read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
Y
Yan Zheng 已提交
2064
				   BTRFS_UUID_SIZE);
2065 2066
		device = btrfs_find_device(root->fs_info, devid, dev_uuid,
					   fs_uuid);
2067
		BUG_ON(!device); /* Logic error */
Y
Yan Zheng 已提交
2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083

		if (device->fs_devices->seeding) {
			btrfs_set_device_generation(leaf, dev_item,
						    device->generation);
			btrfs_mark_buffer_dirty(leaf);
		}

		path->slots[0]++;
		goto next_slot;
	}
	ret = 0;
error:
	btrfs_free_path(path);
	return ret;
}

2084 2085
int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
{
2086
	struct request_queue *q;
2087 2088 2089 2090
	struct btrfs_trans_handle *trans;
	struct btrfs_device *device;
	struct block_device *bdev;
	struct list_head *devices;
Y
Yan Zheng 已提交
2091
	struct super_block *sb = root->fs_info->sb;
2092
	struct rcu_string *name;
2093
	u64 tmp;
Y
Yan Zheng 已提交
2094
	int seeding_dev = 0;
2095 2096
	int ret = 0;

Y
Yan Zheng 已提交
2097
	if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
2098
		return -EROFS;
2099

2100
	bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2101
				  root->fs_info->bdev_holder);
2102 2103
	if (IS_ERR(bdev))
		return PTR_ERR(bdev);
2104

Y
Yan Zheng 已提交
2105 2106 2107 2108 2109 2110
	if (root->fs_info->fs_devices->seeding) {
		seeding_dev = 1;
		down_write(&sb->s_umount);
		mutex_lock(&uuid_mutex);
	}

2111
	filemap_write_and_wait(bdev->bd_inode->i_mapping);
2112

2113
	devices = &root->fs_info->fs_devices->devices;
2114 2115

	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
Q
Qinghuang Feng 已提交
2116
	list_for_each_entry(device, devices, dev_list) {
2117 2118
		if (device->bdev == bdev) {
			ret = -EEXIST;
2119 2120
			mutex_unlock(
				&root->fs_info->fs_devices->device_list_mutex);
Y
Yan Zheng 已提交
2121
			goto error;
2122 2123
		}
	}
2124
	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2125

2126 2127
	device = btrfs_alloc_device(root->fs_info, NULL, NULL);
	if (IS_ERR(device)) {
2128
		/* we can safely leave the fs_devices entry around */
2129
		ret = PTR_ERR(device);
Y
Yan Zheng 已提交
2130
		goto error;
2131 2132
	}

2133 2134
	name = rcu_string_strdup(device_path, GFP_NOFS);
	if (!name) {
2135
		kfree(device);
Y
Yan Zheng 已提交
2136 2137
		ret = -ENOMEM;
		goto error;
2138
	}
2139
	rcu_assign_pointer(device->name, name);
Y
Yan Zheng 已提交
2140

2141
	trans = btrfs_start_transaction(root, 0);
2142
	if (IS_ERR(trans)) {
2143
		rcu_string_free(device->name);
2144 2145 2146 2147 2148
		kfree(device);
		ret = PTR_ERR(trans);
		goto error;
	}

2149 2150 2151
	q = bdev_get_queue(bdev);
	if (blk_queue_discard(q))
		device->can_discard = 1;
Y
Yan Zheng 已提交
2152 2153
	device->writeable = 1;
	device->generation = trans->transid;
2154 2155 2156 2157
	device->io_width = root->sectorsize;
	device->io_align = root->sectorsize;
	device->sector_size = root->sectorsize;
	device->total_bytes = i_size_read(bdev->bd_inode);
2158
	device->disk_total_bytes = device->total_bytes;
2159
	device->commit_total_bytes = device->total_bytes;
2160 2161
	device->dev_root = root->fs_info->dev_root;
	device->bdev = bdev;
2162
	device->in_fs_metadata = 1;
2163
	device->is_tgtdev_for_dev_replace = 0;
2164
	device->mode = FMODE_EXCL;
2165
	device->dev_stats_valid = 1;
Y
Yan Zheng 已提交
2166
	set_blocksize(device->bdev, 4096);
2167

Y
Yan Zheng 已提交
2168 2169
	if (seeding_dev) {
		sb->s_flags &= ~MS_RDONLY;
2170
		ret = btrfs_prepare_sprout(root);
2171
		BUG_ON(ret); /* -ENOMEM */
Y
Yan Zheng 已提交
2172
	}
2173

Y
Yan Zheng 已提交
2174
	device->fs_devices = root->fs_info->fs_devices;
2175 2176

	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
M
Miao Xie 已提交
2177
	lock_chunks(root);
2178
	list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
Y
Yan Zheng 已提交
2179 2180 2181 2182 2183
	list_add(&device->dev_alloc_list,
		 &root->fs_info->fs_devices->alloc_list);
	root->fs_info->fs_devices->num_devices++;
	root->fs_info->fs_devices->open_devices++;
	root->fs_info->fs_devices->rw_devices++;
J
Josef Bacik 已提交
2184
	root->fs_info->fs_devices->total_devices++;
Y
Yan Zheng 已提交
2185
	root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2186

2187 2188 2189 2190
	spin_lock(&root->fs_info->free_chunk_lock);
	root->fs_info->free_chunk_space += device->total_bytes;
	spin_unlock(&root->fs_info->free_chunk_lock);

C
Chris Mason 已提交
2191 2192 2193
	if (!blk_queue_nonrot(bdev_get_queue(bdev)))
		root->fs_info->fs_devices->rotating = 1;

2194
	tmp = btrfs_super_total_bytes(root->fs_info->super_copy);
2195
	btrfs_set_super_total_bytes(root->fs_info->super_copy,
2196
				    tmp + device->total_bytes);
2197

2198
	tmp = btrfs_super_num_devices(root->fs_info->super_copy);
2199
	btrfs_set_super_num_devices(root->fs_info->super_copy,
2200
				    tmp + 1);
2201 2202 2203 2204

	/* add sysfs device entry */
	btrfs_kobj_add_device(root->fs_info, device);

M
Miao Xie 已提交
2205 2206 2207 2208 2209 2210 2211
	/*
	 * we've got more storage, clear any full flags on the space
	 * infos
	 */
	btrfs_clear_space_info_full(root->fs_info);

	unlock_chunks(root);
2212
	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2213

Y
Yan Zheng 已提交
2214
	if (seeding_dev) {
M
Miao Xie 已提交
2215
		lock_chunks(root);
Y
Yan Zheng 已提交
2216
		ret = init_first_rw_device(trans, root, device);
M
Miao Xie 已提交
2217
		unlock_chunks(root);
2218 2219
		if (ret) {
			btrfs_abort_transaction(trans, root, ret);
2220
			goto error_trans;
2221
		}
M
Miao Xie 已提交
2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232
	}

	ret = btrfs_add_device(trans, root, device);
	if (ret) {
		btrfs_abort_transaction(trans, root, ret);
		goto error_trans;
	}

	if (seeding_dev) {
		char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];

Y
Yan Zheng 已提交
2233
		ret = btrfs_finish_sprout(trans, root);
2234 2235
		if (ret) {
			btrfs_abort_transaction(trans, root, ret);
2236
			goto error_trans;
2237
		}
2238 2239 2240 2241 2242 2243 2244 2245

		/* Sprouting would change fsid of the mounted root,
		 * so rename the fsid on the sysfs
		 */
		snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU",
						root->fs_info->fsid);
		if (kobject_rename(&root->fs_info->super_kobj, fsid_buf))
			goto error_trans;
Y
Yan Zheng 已提交
2246 2247
	}

2248 2249
	root->fs_info->num_tolerated_disk_barrier_failures =
		btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2250
	ret = btrfs_commit_transaction(trans, root);
2251

Y
Yan Zheng 已提交
2252 2253 2254
	if (seeding_dev) {
		mutex_unlock(&uuid_mutex);
		up_write(&sb->s_umount);
2255

2256 2257 2258
		if (ret) /* transaction commit */
			return ret;

Y
Yan Zheng 已提交
2259
		ret = btrfs_relocate_sys_chunks(root);
2260 2261 2262 2263 2264
		if (ret < 0)
			btrfs_error(root->fs_info, ret,
				    "Failed to relocate sys chunks after "
				    "device initialization. This can be fixed "
				    "using the \"btrfs balance\" command.");
2265 2266 2267 2268 2269 2270 2271
		trans = btrfs_attach_transaction(root);
		if (IS_ERR(trans)) {
			if (PTR_ERR(trans) == -ENOENT)
				return 0;
			return PTR_ERR(trans);
		}
		ret = btrfs_commit_transaction(trans, root);
Y
Yan Zheng 已提交
2272
	}
2273

2274 2275
	/* Update ctime/mtime for libblkid */
	update_dev_time(device_path);
Y
Yan Zheng 已提交
2276
	return ret;
2277 2278 2279

error_trans:
	btrfs_end_transaction(trans, root);
2280
	rcu_string_free(device->name);
2281
	btrfs_kobj_rm_device(root->fs_info, device);
2282
	kfree(device);
Y
Yan Zheng 已提交
2283
error:
2284
	blkdev_put(bdev, FMODE_EXCL);
Y
Yan Zheng 已提交
2285 2286 2287 2288
	if (seeding_dev) {
		mutex_unlock(&uuid_mutex);
		up_write(&sb->s_umount);
	}
2289
	return ret;
2290 2291
}

2292
int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2293
				  struct btrfs_device *srcdev,
2294 2295 2296 2297 2298 2299 2300 2301
				  struct btrfs_device **device_out)
{
	struct request_queue *q;
	struct btrfs_device *device;
	struct block_device *bdev;
	struct btrfs_fs_info *fs_info = root->fs_info;
	struct list_head *devices;
	struct rcu_string *name;
2302
	u64 devid = BTRFS_DEV_REPLACE_DEVID;
2303 2304 2305
	int ret = 0;

	*device_out = NULL;
2306 2307
	if (fs_info->fs_devices->seeding) {
		btrfs_err(fs_info, "the filesystem is a seed filesystem!");
2308
		return -EINVAL;
2309
	}
2310 2311 2312

	bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
				  fs_info->bdev_holder);
2313 2314
	if (IS_ERR(bdev)) {
		btrfs_err(fs_info, "target device %s is invalid!", device_path);
2315
		return PTR_ERR(bdev);
2316
	}
2317 2318 2319 2320 2321 2322

	filemap_write_and_wait(bdev->bd_inode->i_mapping);

	devices = &fs_info->fs_devices->devices;
	list_for_each_entry(device, devices, dev_list) {
		if (device->bdev == bdev) {
2323
			btrfs_err(fs_info, "target device is in the filesystem!");
2324 2325 2326 2327 2328
			ret = -EEXIST;
			goto error;
		}
	}

2329

2330 2331
	if (i_size_read(bdev->bd_inode) <
	    btrfs_device_get_total_bytes(srcdev)) {
2332 2333 2334 2335 2336 2337
		btrfs_err(fs_info, "target device is smaller than source device!");
		ret = -EINVAL;
		goto error;
	}


2338 2339 2340
	device = btrfs_alloc_device(NULL, &devid, NULL);
	if (IS_ERR(device)) {
		ret = PTR_ERR(device);
2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360
		goto error;
	}

	name = rcu_string_strdup(device_path, GFP_NOFS);
	if (!name) {
		kfree(device);
		ret = -ENOMEM;
		goto error;
	}
	rcu_assign_pointer(device->name, name);

	q = bdev_get_queue(bdev);
	if (blk_queue_discard(q))
		device->can_discard = 1;
	mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
	device->writeable = 1;
	device->generation = 0;
	device->io_width = root->sectorsize;
	device->io_align = root->sectorsize;
	device->sector_size = root->sectorsize;
2361 2362 2363
	device->total_bytes = btrfs_device_get_total_bytes(srcdev);
	device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev);
	device->bytes_used = btrfs_device_get_bytes_used(srcdev);
2364 2365
	ASSERT(list_empty(&srcdev->resized_list));
	device->commit_total_bytes = srcdev->commit_total_bytes;
2366
	device->commit_bytes_used = device->bytes_used;
2367 2368 2369 2370 2371
	device->dev_root = fs_info->dev_root;
	device->bdev = bdev;
	device->in_fs_metadata = 1;
	device->is_tgtdev_for_dev_replace = 1;
	device->mode = FMODE_EXCL;
2372
	device->dev_stats_valid = 1;
2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398
	set_blocksize(device->bdev, 4096);
	device->fs_devices = fs_info->fs_devices;
	list_add(&device->dev_list, &fs_info->fs_devices->devices);
	fs_info->fs_devices->num_devices++;
	fs_info->fs_devices->open_devices++;
	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);

	*device_out = device;
	return ret;

error:
	blkdev_put(bdev, FMODE_EXCL);
	return ret;
}

void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
					      struct btrfs_device *tgtdev)
{
	WARN_ON(fs_info->fs_devices->rw_devices == 0);
	tgtdev->io_width = fs_info->dev_root->sectorsize;
	tgtdev->io_align = fs_info->dev_root->sectorsize;
	tgtdev->sector_size = fs_info->dev_root->sectorsize;
	tgtdev->dev_root = fs_info->dev_root;
	tgtdev->in_fs_metadata = 1;
}

C
Chris Mason 已提交
2399 2400
static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
					struct btrfs_device *device)
2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435
{
	int ret;
	struct btrfs_path *path;
	struct btrfs_root *root;
	struct btrfs_dev_item *dev_item;
	struct extent_buffer *leaf;
	struct btrfs_key key;

	root = device->dev_root->fs_info->chunk_root;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.type = BTRFS_DEV_ITEM_KEY;
	key.offset = device->devid;

	ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
	if (ret < 0)
		goto out;

	if (ret > 0) {
		ret = -ENOENT;
		goto out;
	}

	leaf = path->nodes[0];
	dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);

	btrfs_set_device_id(leaf, dev_item, device->devid);
	btrfs_set_device_type(leaf, dev_item, device->type);
	btrfs_set_device_io_align(leaf, dev_item, device->io_align);
	btrfs_set_device_io_width(leaf, dev_item, device->io_width);
	btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2436 2437 2438 2439
	btrfs_set_device_total_bytes(leaf, dev_item,
				     btrfs_device_get_disk_total_bytes(device));
	btrfs_set_device_bytes_used(leaf, dev_item,
				    btrfs_device_get_bytes_used(device));
2440 2441 2442 2443 2444 2445 2446
	btrfs_mark_buffer_dirty(leaf);

out:
	btrfs_free_path(path);
	return ret;
}

M
Miao Xie 已提交
2447
int btrfs_grow_device(struct btrfs_trans_handle *trans,
2448 2449 2450
		      struct btrfs_device *device, u64 new_size)
{
	struct btrfs_super_block *super_copy =
2451
		device->dev_root->fs_info->super_copy;
2452
	struct btrfs_fs_devices *fs_devices;
M
Miao Xie 已提交
2453 2454
	u64 old_total;
	u64 diff;
2455

Y
Yan Zheng 已提交
2456 2457
	if (!device->writeable)
		return -EACCES;
M
Miao Xie 已提交
2458 2459 2460 2461 2462

	lock_chunks(device->dev_root);
	old_total = btrfs_super_total_bytes(super_copy);
	diff = new_size - device->total_bytes;

2463
	if (new_size <= device->total_bytes ||
M
Miao Xie 已提交
2464 2465
	    device->is_tgtdev_for_dev_replace) {
		unlock_chunks(device->dev_root);
Y
Yan Zheng 已提交
2466
		return -EINVAL;
M
Miao Xie 已提交
2467
	}
Y
Yan Zheng 已提交
2468

2469
	fs_devices = device->dev_root->fs_info->fs_devices;
Y
Yan Zheng 已提交
2470

2471
	btrfs_set_super_total_bytes(super_copy, old_total + diff);
Y
Yan Zheng 已提交
2472 2473
	device->fs_devices->total_rw_bytes += diff;

2474 2475
	btrfs_device_set_total_bytes(device, new_size);
	btrfs_device_set_disk_total_bytes(device, new_size);
2476
	btrfs_clear_space_info_full(device->dev_root->fs_info);
2477 2478 2479
	if (list_empty(&device->resized_list))
		list_add_tail(&device->resized_list,
			      &fs_devices->resized_devices);
M
Miao Xie 已提交
2480
	unlock_chunks(device->dev_root);
2481

2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503
	return btrfs_update_device(trans, device);
}

static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
			    struct btrfs_root *root,
			    u64 chunk_tree, u64 chunk_objectid,
			    u64 chunk_offset)
{
	int ret;
	struct btrfs_path *path;
	struct btrfs_key key;

	root = root->fs_info->chunk_root;
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = chunk_objectid;
	key.offset = chunk_offset;
	key.type = BTRFS_CHUNK_ITEM_KEY;

	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2504 2505 2506 2507 2508 2509 2510 2511
	if (ret < 0)
		goto out;
	else if (ret > 0) { /* Logic error or corruption */
		btrfs_error(root->fs_info, -ENOENT,
			    "Failed lookup while freeing chunk.");
		ret = -ENOENT;
		goto out;
	}
2512 2513

	ret = btrfs_del_item(trans, root, path);
2514 2515 2516 2517
	if (ret < 0)
		btrfs_error(root->fs_info, ret,
			    "Failed to delete chunk item.");
out:
2518
	btrfs_free_path(path);
2519
	return ret;
2520 2521
}

2522
static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2523 2524
			chunk_offset)
{
2525
	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2526 2527 2528 2529 2530 2531 2532 2533 2534 2535
	struct btrfs_disk_key *disk_key;
	struct btrfs_chunk *chunk;
	u8 *ptr;
	int ret = 0;
	u32 num_stripes;
	u32 array_size;
	u32 len = 0;
	u32 cur;
	struct btrfs_key key;

M
Miao Xie 已提交
2536
	lock_chunks(root);
2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565
	array_size = btrfs_super_sys_array_size(super_copy);

	ptr = super_copy->sys_chunk_array;
	cur = 0;

	while (cur < array_size) {
		disk_key = (struct btrfs_disk_key *)ptr;
		btrfs_disk_key_to_cpu(&key, disk_key);

		len = sizeof(*disk_key);

		if (key.type == BTRFS_CHUNK_ITEM_KEY) {
			chunk = (struct btrfs_chunk *)(ptr + len);
			num_stripes = btrfs_stack_chunk_num_stripes(chunk);
			len += btrfs_chunk_item_size(num_stripes);
		} else {
			ret = -EIO;
			break;
		}
		if (key.objectid == chunk_objectid &&
		    key.offset == chunk_offset) {
			memmove(ptr, ptr + len, array_size - (cur + len));
			array_size -= len;
			btrfs_set_super_sys_array_size(super_copy, array_size);
		} else {
			ptr += len;
			cur += len;
		}
	}
M
Miao Xie 已提交
2566
	unlock_chunks(root);
2567 2568 2569
	return ret;
}

2570 2571
int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
		       struct btrfs_root *root, u64 chunk_offset)
2572 2573 2574
{
	struct extent_map_tree *em_tree;
	struct extent_map *em;
2575
	struct btrfs_root *extent_root = root->fs_info->extent_root;
2576
	struct map_lookup *map;
M
Miao Xie 已提交
2577
	u64 dev_extent_len = 0;
2578 2579 2580
	u64 chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
	u64 chunk_tree = root->fs_info->chunk_root->objectid;
	int i, ret = 0;
2581

2582
	/* Just in case */
2583 2584 2585
	root = root->fs_info->chunk_root;
	em_tree = &root->fs_info->mapping_tree.map_tree;

2586
	read_lock(&em_tree->lock);
2587
	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2588
	read_unlock(&em_tree->lock);
2589

2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601
	if (!em || em->start > chunk_offset ||
	    em->start + em->len < chunk_offset) {
		/*
		 * This is a logic error, but we don't want to just rely on the
		 * user having built with ASSERT enabled, so if ASSERT doens't
		 * do anything we still error out.
		 */
		ASSERT(0);
		if (em)
			free_extent_map(em);
		return -EINVAL;
	}
2602 2603 2604
	map = (struct map_lookup *)em->bdev;

	for (i = 0; i < map->num_stripes; i++) {
2605
		struct btrfs_device *device = map->stripes[i].dev;
M
Miao Xie 已提交
2606 2607 2608
		ret = btrfs_free_dev_extent(trans, device,
					    map->stripes[i].physical,
					    &dev_extent_len);
2609 2610 2611 2612
		if (ret) {
			btrfs_abort_transaction(trans, root, ret);
			goto out;
		}
2613

M
Miao Xie 已提交
2614 2615 2616 2617 2618 2619 2620 2621 2622 2623
		if (device->bytes_used > 0) {
			lock_chunks(root);
			btrfs_device_set_bytes_used(device,
					device->bytes_used - dev_extent_len);
			spin_lock(&root->fs_info->free_chunk_lock);
			root->fs_info->free_chunk_space += dev_extent_len;
			spin_unlock(&root->fs_info->free_chunk_lock);
			btrfs_clear_space_info_full(root->fs_info);
			unlock_chunks(root);
		}
2624

2625 2626
		if (map->stripes[i].dev) {
			ret = btrfs_update_device(trans, map->stripes[i].dev);
2627 2628 2629 2630
			if (ret) {
				btrfs_abort_transaction(trans, root, ret);
				goto out;
			}
2631
		}
2632 2633 2634
	}
	ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
			       chunk_offset);
2635 2636 2637 2638
	if (ret) {
		btrfs_abort_transaction(trans, root, ret);
		goto out;
	}
2639

2640 2641
	trace_btrfs_chunk_free(root, map, chunk_offset, em->len);

2642 2643
	if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
		ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2644 2645 2646 2647
		if (ret) {
			btrfs_abort_transaction(trans, root, ret);
			goto out;
		}
2648 2649
	}

Y
Yan Zheng 已提交
2650
	ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2651 2652 2653 2654
	if (ret) {
		btrfs_abort_transaction(trans, extent_root, ret);
		goto out;
	}
Y
Yan Zheng 已提交
2655

2656
	write_lock(&em_tree->lock);
Y
Yan Zheng 已提交
2657
	remove_extent_mapping(em_tree, em);
2658
	write_unlock(&em_tree->lock);
Y
Yan Zheng 已提交
2659 2660 2661

	/* once for the tree */
	free_extent_map(em);
2662
out:
Y
Yan Zheng 已提交
2663 2664
	/* once for us */
	free_extent_map(em);
2665 2666
	return ret;
}
Y
Yan Zheng 已提交
2667

2668 2669 2670 2671 2672 2673 2674
static int btrfs_relocate_chunk(struct btrfs_root *root,
			 u64 chunk_tree, u64 chunk_objectid,
			 u64 chunk_offset)
{
	struct btrfs_root *extent_root;
	struct btrfs_trans_handle *trans;
	int ret;
Y
Yan Zheng 已提交
2675

2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699
	root = root->fs_info->chunk_root;
	extent_root = root->fs_info->extent_root;

	ret = btrfs_can_relocate(extent_root, chunk_offset);
	if (ret)
		return -ENOSPC;

	/* step one, relocate all the extents inside this chunk */
	ret = btrfs_relocate_block_group(extent_root, chunk_offset);
	if (ret)
		return ret;

	trans = btrfs_start_transaction(root, 0);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		btrfs_std_error(root->fs_info, ret);
		return ret;
	}

	/*
	 * step two, delete the device extents and the
	 * chunk tree entries
	 */
	ret = btrfs_remove_chunk(trans, root, chunk_offset);
Y
Yan Zheng 已提交
2700
	btrfs_end_transaction(trans, root);
2701
	return ret;
Y
Yan Zheng 已提交
2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713
}

static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
{
	struct btrfs_root *chunk_root = root->fs_info->chunk_root;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_chunk *chunk;
	struct btrfs_key key;
	struct btrfs_key found_key;
	u64 chunk_tree = chunk_root->root_key.objectid;
	u64 chunk_type;
2714 2715
	bool retried = false;
	int failed = 0;
Y
Yan Zheng 已提交
2716 2717 2718 2719 2720 2721
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

2722
again:
Y
Yan Zheng 已提交
2723 2724 2725 2726 2727 2728 2729 2730
	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
	key.offset = (u64)-1;
	key.type = BTRFS_CHUNK_ITEM_KEY;

	while (1) {
		ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
		if (ret < 0)
			goto error;
2731
		BUG_ON(ret == 0); /* Corruption */
Y
Yan Zheng 已提交
2732 2733 2734 2735 2736 2737 2738

		ret = btrfs_previous_item(chunk_root, path, key.objectid,
					  key.type);
		if (ret < 0)
			goto error;
		if (ret > 0)
			break;
Z
Zheng Yan 已提交
2739

Y
Yan Zheng 已提交
2740 2741
		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
Z
Zheng Yan 已提交
2742

Y
Yan Zheng 已提交
2743 2744 2745
		chunk = btrfs_item_ptr(leaf, path->slots[0],
				       struct btrfs_chunk);
		chunk_type = btrfs_chunk_type(leaf, chunk);
2746
		btrfs_release_path(path);
2747

Y
Yan Zheng 已提交
2748 2749 2750 2751
		if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
			ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
						   found_key.objectid,
						   found_key.offset);
2752 2753
			if (ret == -ENOSPC)
				failed++;
H
HIMANGI SARAOGI 已提交
2754 2755
			else
				BUG_ON(ret);
Y
Yan Zheng 已提交
2756
		}
2757

Y
Yan Zheng 已提交
2758 2759 2760 2761 2762
		if (found_key.offset == 0)
			break;
		key.offset = found_key.offset - 1;
	}
	ret = 0;
2763 2764 2765 2766
	if (failed && !retried) {
		failed = 0;
		retried = true;
		goto again;
2767
	} else if (WARN_ON(failed && retried)) {
2768 2769
		ret = -ENOSPC;
	}
Y
Yan Zheng 已提交
2770 2771 2772
error:
	btrfs_free_path(path);
	return ret;
2773 2774
}

2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865
static int insert_balance_item(struct btrfs_root *root,
			       struct btrfs_balance_control *bctl)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_balance_item *item;
	struct btrfs_disk_balance_args disk_bargs;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_key key;
	int ret, err;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	trans = btrfs_start_transaction(root, 0);
	if (IS_ERR(trans)) {
		btrfs_free_path(path);
		return PTR_ERR(trans);
	}

	key.objectid = BTRFS_BALANCE_OBJECTID;
	key.type = BTRFS_BALANCE_ITEM_KEY;
	key.offset = 0;

	ret = btrfs_insert_empty_item(trans, root, path, &key,
				      sizeof(*item));
	if (ret)
		goto out;

	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);

	memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));

	btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
	btrfs_set_balance_data(leaf, item, &disk_bargs);
	btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
	btrfs_set_balance_meta(leaf, item, &disk_bargs);
	btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
	btrfs_set_balance_sys(leaf, item, &disk_bargs);

	btrfs_set_balance_flags(leaf, item, bctl->flags);

	btrfs_mark_buffer_dirty(leaf);
out:
	btrfs_free_path(path);
	err = btrfs_commit_transaction(trans, root);
	if (err && !ret)
		ret = err;
	return ret;
}

static int del_balance_item(struct btrfs_root *root)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_path *path;
	struct btrfs_key key;
	int ret, err;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	trans = btrfs_start_transaction(root, 0);
	if (IS_ERR(trans)) {
		btrfs_free_path(path);
		return PTR_ERR(trans);
	}

	key.objectid = BTRFS_BALANCE_OBJECTID;
	key.type = BTRFS_BALANCE_ITEM_KEY;
	key.offset = 0;

	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	if (ret < 0)
		goto out;
	if (ret > 0) {
		ret = -ENOENT;
		goto out;
	}

	ret = btrfs_del_item(trans, root, path);
out:
	btrfs_free_path(path);
	err = btrfs_commit_transaction(trans, root);
	if (err && !ret)
		ret = err;
	return ret;
}

I
Ilya Dryomov 已提交
2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905
/*
 * This is a heuristic used to reduce the number of chunks balanced on
 * resume after balance was interrupted.
 */
static void update_balance_args(struct btrfs_balance_control *bctl)
{
	/*
	 * Turn on soft mode for chunk types that were being converted.
	 */
	if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
		bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
		bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
	if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
		bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;

	/*
	 * Turn on usage filter if is not already used.  The idea is
	 * that chunks that we have already balanced should be
	 * reasonably full.  Don't do it for chunks that are being
	 * converted - that will keep us from relocating unconverted
	 * (albeit full) chunks.
	 */
	if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
	    !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
		bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
		bctl->data.usage = 90;
	}
	if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
	    !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
		bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
		bctl->sys.usage = 90;
	}
	if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
	    !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
		bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
		bctl->meta.usage = 90;
	}
}

2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934
/*
 * Should be called with both balance and volume mutexes held to
 * serialize other volume operations (add_dev/rm_dev/resize) with
 * restriper.  Same goes for unset_balance_control.
 */
static void set_balance_control(struct btrfs_balance_control *bctl)
{
	struct btrfs_fs_info *fs_info = bctl->fs_info;

	BUG_ON(fs_info->balance_ctl);

	spin_lock(&fs_info->balance_lock);
	fs_info->balance_ctl = bctl;
	spin_unlock(&fs_info->balance_lock);
}

static void unset_balance_control(struct btrfs_fs_info *fs_info)
{
	struct btrfs_balance_control *bctl = fs_info->balance_ctl;

	BUG_ON(!fs_info->balance_ctl);

	spin_lock(&fs_info->balance_lock);
	fs_info->balance_ctl = NULL;
	spin_unlock(&fs_info->balance_lock);

	kfree(bctl);
}

I
Ilya Dryomov 已提交
2935 2936 2937 2938
/*
 * Balance filters.  Return 1 if chunk should be filtered out
 * (should not be balanced).
 */
2939
static int chunk_profiles_filter(u64 chunk_type,
I
Ilya Dryomov 已提交
2940 2941
				 struct btrfs_balance_args *bargs)
{
2942 2943
	chunk_type = chunk_to_extended(chunk_type) &
				BTRFS_EXTENDED_PROFILE_MASK;
I
Ilya Dryomov 已提交
2944

2945
	if (bargs->profiles & chunk_type)
I
Ilya Dryomov 已提交
2946 2947 2948 2949 2950
		return 0;

	return 1;
}

I
Ilya Dryomov 已提交
2951 2952 2953 2954 2955 2956 2957 2958 2959 2960
static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
			      struct btrfs_balance_args *bargs)
{
	struct btrfs_block_group_cache *cache;
	u64 chunk_used, user_thresh;
	int ret = 1;

	cache = btrfs_lookup_block_group(fs_info, chunk_offset);
	chunk_used = btrfs_block_group_used(&cache->item);

2961
	if (bargs->usage == 0)
2962
		user_thresh = 1;
2963 2964 2965 2966 2967 2968
	else if (bargs->usage > 100)
		user_thresh = cache->key.offset;
	else
		user_thresh = div_factor_fine(cache->key.offset,
					      bargs->usage);

I
Ilya Dryomov 已提交
2969 2970 2971 2972 2973 2974 2975
	if (chunk_used < user_thresh)
		ret = 0;

	btrfs_put_block_group(cache);
	return ret;
}

I
Ilya Dryomov 已提交
2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992
static int chunk_devid_filter(struct extent_buffer *leaf,
			      struct btrfs_chunk *chunk,
			      struct btrfs_balance_args *bargs)
{
	struct btrfs_stripe *stripe;
	int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
	int i;

	for (i = 0; i < num_stripes; i++) {
		stripe = btrfs_stripe_nr(chunk, i);
		if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
			return 0;
	}

	return 1;
}

I
Ilya Dryomov 已提交
2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009
/* [pstart, pend) */
static int chunk_drange_filter(struct extent_buffer *leaf,
			       struct btrfs_chunk *chunk,
			       u64 chunk_offset,
			       struct btrfs_balance_args *bargs)
{
	struct btrfs_stripe *stripe;
	int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
	u64 stripe_offset;
	u64 stripe_length;
	int factor;
	int i;

	if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
		return 0;

	if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
D
David Woodhouse 已提交
3010 3011 3012 3013 3014 3015 3016 3017 3018
	     BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
		factor = num_stripes / 2;
	} else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
		factor = num_stripes - 1;
	} else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
		factor = num_stripes - 2;
	} else {
		factor = num_stripes;
	}
I
Ilya Dryomov 已提交
3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036

	for (i = 0; i < num_stripes; i++) {
		stripe = btrfs_stripe_nr(chunk, i);
		if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
			continue;

		stripe_offset = btrfs_stripe_offset(leaf, stripe);
		stripe_length = btrfs_chunk_length(leaf, chunk);
		do_div(stripe_length, factor);

		if (stripe_offset < bargs->pend &&
		    stripe_offset + stripe_length > bargs->pstart)
			return 0;
	}

	return 1;
}

3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050
/* [vstart, vend) */
static int chunk_vrange_filter(struct extent_buffer *leaf,
			       struct btrfs_chunk *chunk,
			       u64 chunk_offset,
			       struct btrfs_balance_args *bargs)
{
	if (chunk_offset < bargs->vend &&
	    chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
		/* at least part of the chunk is inside this vrange */
		return 0;

	return 1;
}

3051
static int chunk_soft_convert_filter(u64 chunk_type,
3052 3053 3054 3055 3056
				     struct btrfs_balance_args *bargs)
{
	if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
		return 0;

3057 3058
	chunk_type = chunk_to_extended(chunk_type) &
				BTRFS_EXTENDED_PROFILE_MASK;
3059

3060
	if (bargs->target == chunk_type)
3061 3062 3063 3064 3065
		return 1;

	return 0;
}

3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086
static int should_balance_chunk(struct btrfs_root *root,
				struct extent_buffer *leaf,
				struct btrfs_chunk *chunk, u64 chunk_offset)
{
	struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
	struct btrfs_balance_args *bargs = NULL;
	u64 chunk_type = btrfs_chunk_type(leaf, chunk);

	/* type filter */
	if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
	      (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
		return 0;
	}

	if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
		bargs = &bctl->data;
	else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
		bargs = &bctl->sys;
	else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
		bargs = &bctl->meta;

I
Ilya Dryomov 已提交
3087 3088 3089 3090
	/* profiles filter */
	if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
	    chunk_profiles_filter(chunk_type, bargs)) {
		return 0;
I
Ilya Dryomov 已提交
3091 3092 3093 3094 3095 3096
	}

	/* usage filter */
	if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
	    chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
		return 0;
I
Ilya Dryomov 已提交
3097 3098 3099 3100 3101 3102
	}

	/* devid filter */
	if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
	    chunk_devid_filter(leaf, chunk, bargs)) {
		return 0;
I
Ilya Dryomov 已提交
3103 3104 3105 3106 3107 3108
	}

	/* drange filter, makes sense only with devid filter */
	if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
	    chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
		return 0;
3109 3110 3111 3112 3113 3114
	}

	/* vrange filter */
	if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
	    chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
		return 0;
I
Ilya Dryomov 已提交
3115 3116
	}

3117 3118 3119 3120 3121 3122
	/* soft profile changing mode */
	if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
	    chunk_soft_convert_filter(chunk_type, bargs)) {
		return 0;
	}

3123 3124 3125 3126 3127 3128 3129 3130 3131 3132
	/*
	 * limited by count, must be the last filter
	 */
	if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT)) {
		if (bargs->limit == 0)
			return 0;
		else
			bargs->limit--;
	}

3133 3134 3135
	return 1;
}

3136
static int __btrfs_balance(struct btrfs_fs_info *fs_info)
3137
{
3138
	struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3139 3140 3141
	struct btrfs_root *chunk_root = fs_info->chunk_root;
	struct btrfs_root *dev_root = fs_info->dev_root;
	struct list_head *devices;
3142 3143 3144
	struct btrfs_device *device;
	u64 old_size;
	u64 size_to_free;
3145
	struct btrfs_chunk *chunk;
3146 3147 3148
	struct btrfs_path *path;
	struct btrfs_key key;
	struct btrfs_key found_key;
3149
	struct btrfs_trans_handle *trans;
3150 3151
	struct extent_buffer *leaf;
	int slot;
3152 3153
	int ret;
	int enospc_errors = 0;
3154
	bool counting = true;
3155 3156 3157
	u64 limit_data = bctl->data.limit;
	u64 limit_meta = bctl->meta.limit;
	u64 limit_sys = bctl->sys.limit;
3158 3159

	/* step one make some room on all the devices */
3160
	devices = &fs_info->fs_devices->devices;
Q
Qinghuang Feng 已提交
3161
	list_for_each_entry(device, devices, dev_list) {
3162
		old_size = btrfs_device_get_total_bytes(device);
3163 3164
		size_to_free = div_factor(old_size, 1);
		size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
Y
Yan Zheng 已提交
3165
		if (!device->writeable ||
3166 3167
		    btrfs_device_get_total_bytes(device) -
		    btrfs_device_get_bytes_used(device) > size_to_free ||
3168
		    device->is_tgtdev_for_dev_replace)
3169 3170 3171
			continue;

		ret = btrfs_shrink_device(device, old_size - size_to_free);
3172 3173
		if (ret == -ENOSPC)
			break;
3174 3175
		BUG_ON(ret);

3176
		trans = btrfs_start_transaction(dev_root, 0);
3177
		BUG_ON(IS_ERR(trans));
3178 3179 3180 3181 3182 3183 3184 3185 3186

		ret = btrfs_grow_device(trans, device, old_size);
		BUG_ON(ret);

		btrfs_end_transaction(trans, dev_root);
	}

	/* step two, relocate all the chunks */
	path = btrfs_alloc_path();
3187 3188 3189 3190
	if (!path) {
		ret = -ENOMEM;
		goto error;
	}
3191 3192 3193 3194 3195 3196

	/* zero out stat counters */
	spin_lock(&fs_info->balance_lock);
	memset(&bctl->stat, 0, sizeof(bctl->stat));
	spin_unlock(&fs_info->balance_lock);
again:
3197 3198 3199 3200 3201
	if (!counting) {
		bctl->data.limit = limit_data;
		bctl->meta.limit = limit_meta;
		bctl->sys.limit = limit_sys;
	}
3202 3203 3204 3205
	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
	key.offset = (u64)-1;
	key.type = BTRFS_CHUNK_ITEM_KEY;

C
Chris Mason 已提交
3206
	while (1) {
3207
		if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
3208
		    atomic_read(&fs_info->balance_cancel_req)) {
3209 3210 3211 3212
			ret = -ECANCELED;
			goto error;
		}

3213 3214 3215 3216 3217 3218 3219 3220 3221
		ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
		if (ret < 0)
			goto error;

		/*
		 * this shouldn't happen, it means the last relocate
		 * failed
		 */
		if (ret == 0)
3222
			BUG(); /* FIXME break ? */
3223 3224 3225

		ret = btrfs_previous_item(chunk_root, path, 0,
					  BTRFS_CHUNK_ITEM_KEY);
3226 3227
		if (ret) {
			ret = 0;
3228
			break;
3229
		}
3230

3231 3232 3233
		leaf = path->nodes[0];
		slot = path->slots[0];
		btrfs_item_key_to_cpu(leaf, &found_key, slot);
3234

3235 3236
		if (found_key.objectid != key.objectid)
			break;
3237

3238 3239
		chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);

3240 3241 3242 3243 3244 3245
		if (!counting) {
			spin_lock(&fs_info->balance_lock);
			bctl->stat.considered++;
			spin_unlock(&fs_info->balance_lock);
		}

3246 3247
		ret = should_balance_chunk(chunk_root, leaf, chunk,
					   found_key.offset);
3248
		btrfs_release_path(path);
3249 3250 3251
		if (!ret)
			goto loop;

3252 3253 3254 3255 3256 3257 3258
		if (counting) {
			spin_lock(&fs_info->balance_lock);
			bctl->stat.expected++;
			spin_unlock(&fs_info->balance_lock);
			goto loop;
		}

3259 3260 3261 3262
		ret = btrfs_relocate_chunk(chunk_root,
					   chunk_root->root_key.objectid,
					   found_key.objectid,
					   found_key.offset);
3263 3264
		if (ret && ret != -ENOSPC)
			goto error;
3265
		if (ret == -ENOSPC) {
3266
			enospc_errors++;
3267 3268 3269 3270 3271
		} else {
			spin_lock(&fs_info->balance_lock);
			bctl->stat.completed++;
			spin_unlock(&fs_info->balance_lock);
		}
3272
loop:
3273 3274
		if (found_key.offset == 0)
			break;
3275
		key.offset = found_key.offset - 1;
3276
	}
3277

3278 3279 3280 3281 3282
	if (counting) {
		btrfs_release_path(path);
		counting = false;
		goto again;
	}
3283 3284
error:
	btrfs_free_path(path);
3285
	if (enospc_errors) {
3286
		btrfs_info(fs_info, "%d enospc errors during balance",
3287 3288 3289 3290 3291
		       enospc_errors);
		if (!ret)
			ret = -ENOSPC;
	}

3292 3293 3294
	return ret;
}

3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318
/**
 * alloc_profile_is_valid - see if a given profile is valid and reduced
 * @flags: profile to validate
 * @extended: if true @flags is treated as an extended profile
 */
static int alloc_profile_is_valid(u64 flags, int extended)
{
	u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
			       BTRFS_BLOCK_GROUP_PROFILE_MASK);

	flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;

	/* 1) check that all other bits are zeroed */
	if (flags & ~mask)
		return 0;

	/* 2) see if profile is reduced */
	if (flags == 0)
		return !extended; /* "0" is valid for usual profiles */

	/* true if exactly one bit set */
	return (flags & (flags - 1)) == 0;
}

3319 3320
static inline int balance_need_close(struct btrfs_fs_info *fs_info)
{
3321 3322 3323 3324
	/* cancel requested || normal exit path */
	return atomic_read(&fs_info->balance_cancel_req) ||
		(atomic_read(&fs_info->balance_pause_req) == 0 &&
		 atomic_read(&fs_info->balance_cancel_req) == 0);
3325 3326
}

3327 3328
static void __cancel_balance(struct btrfs_fs_info *fs_info)
{
3329 3330
	int ret;

3331
	unset_balance_control(fs_info);
3332
	ret = del_balance_item(fs_info->tree_root);
3333 3334
	if (ret)
		btrfs_std_error(fs_info, ret);
3335 3336

	atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3337 3338 3339 3340 3341 3342 3343 3344 3345
}

/*
 * Should be called with both balance and volume mutexes held
 */
int btrfs_balance(struct btrfs_balance_control *bctl,
		  struct btrfs_ioctl_balance_args *bargs)
{
	struct btrfs_fs_info *fs_info = bctl->fs_info;
3346
	u64 allowed;
3347
	int mixed = 0;
3348
	int ret;
3349
	u64 num_devices;
3350
	unsigned seq;
3351

3352
	if (btrfs_fs_closing(fs_info) ||
3353 3354
	    atomic_read(&fs_info->balance_pause_req) ||
	    atomic_read(&fs_info->balance_cancel_req)) {
3355 3356 3357 3358
		ret = -EINVAL;
		goto out;
	}

3359 3360 3361 3362
	allowed = btrfs_super_incompat_flags(fs_info->super_copy);
	if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
		mixed = 1;

3363 3364 3365 3366
	/*
	 * In case of mixed groups both data and meta should be picked,
	 * and identical options should be given for both of them.
	 */
3367 3368
	allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
	if (mixed && (bctl->flags & allowed)) {
3369 3370 3371
		if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
		    !(bctl->flags & BTRFS_BALANCE_METADATA) ||
		    memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3372 3373
			btrfs_err(fs_info, "with mixed groups data and "
				   "metadata balance options must be the same");
3374 3375 3376 3377 3378
			ret = -EINVAL;
			goto out;
		}
	}

3379 3380 3381 3382 3383 3384 3385
	num_devices = fs_info->fs_devices->num_devices;
	btrfs_dev_replace_lock(&fs_info->dev_replace);
	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
		BUG_ON(num_devices < 1);
		num_devices--;
	}
	btrfs_dev_replace_unlock(&fs_info->dev_replace);
3386
	allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3387
	if (num_devices == 1)
3388
		allowed |= BTRFS_BLOCK_GROUP_DUP;
3389
	else if (num_devices > 1)
3390
		allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3391 3392 3393 3394 3395
	if (num_devices > 2)
		allowed |= BTRFS_BLOCK_GROUP_RAID5;
	if (num_devices > 3)
		allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
			    BTRFS_BLOCK_GROUP_RAID6);
3396 3397 3398
	if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
	    (!alloc_profile_is_valid(bctl->data.target, 1) ||
	     (bctl->data.target & ~allowed))) {
3399 3400
		btrfs_err(fs_info, "unable to start balance with target "
			   "data profile %llu",
3401
		       bctl->data.target);
3402 3403 3404
		ret = -EINVAL;
		goto out;
	}
3405 3406 3407
	if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
	    (!alloc_profile_is_valid(bctl->meta.target, 1) ||
	     (bctl->meta.target & ~allowed))) {
3408 3409
		btrfs_err(fs_info,
			   "unable to start balance with target metadata profile %llu",
3410
		       bctl->meta.target);
3411 3412 3413
		ret = -EINVAL;
		goto out;
	}
3414 3415 3416
	if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
	    (!alloc_profile_is_valid(bctl->sys.target, 1) ||
	     (bctl->sys.target & ~allowed))) {
3417 3418
		btrfs_err(fs_info,
			   "unable to start balance with target system profile %llu",
3419
		       bctl->sys.target);
3420 3421 3422 3423
		ret = -EINVAL;
		goto out;
	}

3424 3425
	/* allow dup'ed data chunks only in mixed mode */
	if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3426
	    (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3427
		btrfs_err(fs_info, "dup for data is not allowed");
3428 3429 3430 3431 3432 3433
		ret = -EINVAL;
		goto out;
	}

	/* allow to reduce meta or sys integrity only if force set */
	allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
D
David Woodhouse 已提交
3434 3435 3436
			BTRFS_BLOCK_GROUP_RAID10 |
			BTRFS_BLOCK_GROUP_RAID5 |
			BTRFS_BLOCK_GROUP_RAID6;
3437 3438 3439 3440 3441 3442 3443 3444 3445 3446
	do {
		seq = read_seqbegin(&fs_info->profiles_lock);

		if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
		     (fs_info->avail_system_alloc_bits & allowed) &&
		     !(bctl->sys.target & allowed)) ||
		    ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
		     (fs_info->avail_metadata_alloc_bits & allowed) &&
		     !(bctl->meta.target & allowed))) {
			if (bctl->flags & BTRFS_BALANCE_FORCE) {
3447
				btrfs_info(fs_info, "force reducing metadata integrity");
3448
			} else {
3449 3450
				btrfs_err(fs_info, "balance will reduce metadata "
					   "integrity, use force if you want this");
3451 3452 3453
				ret = -EINVAL;
				goto out;
			}
3454
		}
3455
	} while (read_seqretry(&fs_info->profiles_lock, seq));
3456

3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476
	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
		int num_tolerated_disk_barrier_failures;
		u64 target = bctl->sys.target;

		num_tolerated_disk_barrier_failures =
			btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
		if (num_tolerated_disk_barrier_failures > 0 &&
		    (target &
		     (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
		      BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
			num_tolerated_disk_barrier_failures = 0;
		else if (num_tolerated_disk_barrier_failures > 1 &&
			 (target &
			  (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
			num_tolerated_disk_barrier_failures = 1;

		fs_info->num_tolerated_disk_barrier_failures =
			num_tolerated_disk_barrier_failures;
	}

3477
	ret = insert_balance_item(fs_info->tree_root, bctl);
I
Ilya Dryomov 已提交
3478
	if (ret && ret != -EEXIST)
3479 3480
		goto out;

I
Ilya Dryomov 已提交
3481 3482 3483 3484 3485 3486 3487 3488 3489
	if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
		BUG_ON(ret == -EEXIST);
		set_balance_control(bctl);
	} else {
		BUG_ON(ret != -EEXIST);
		spin_lock(&fs_info->balance_lock);
		update_balance_args(bctl);
		spin_unlock(&fs_info->balance_lock);
	}
3490

3491
	atomic_inc(&fs_info->balance_running);
3492 3493 3494 3495 3496
	mutex_unlock(&fs_info->balance_mutex);

	ret = __btrfs_balance(fs_info);

	mutex_lock(&fs_info->balance_mutex);
3497
	atomic_dec(&fs_info->balance_running);
3498

3499 3500 3501 3502 3503
	if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
		fs_info->num_tolerated_disk_barrier_failures =
			btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
	}

3504 3505
	if (bargs) {
		memset(bargs, 0, sizeof(*bargs));
3506
		update_ioctl_balance_args(fs_info, 0, bargs);
3507 3508
	}

3509 3510 3511 3512 3513
	if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
	    balance_need_close(fs_info)) {
		__cancel_balance(fs_info);
	}

3514
	wake_up(&fs_info->balance_wait_q);
3515 3516 3517

	return ret;
out:
I
Ilya Dryomov 已提交
3518 3519
	if (bctl->flags & BTRFS_BALANCE_RESUME)
		__cancel_balance(fs_info);
3520
	else {
I
Ilya Dryomov 已提交
3521
		kfree(bctl);
3522 3523
		atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
	}
I
Ilya Dryomov 已提交
3524 3525 3526 3527 3528
	return ret;
}

static int balance_kthread(void *data)
{
3529
	struct btrfs_fs_info *fs_info = data;
3530
	int ret = 0;
I
Ilya Dryomov 已提交
3531 3532 3533 3534

	mutex_lock(&fs_info->volume_mutex);
	mutex_lock(&fs_info->balance_mutex);

3535
	if (fs_info->balance_ctl) {
3536
		btrfs_info(fs_info, "continuing balance");
3537
		ret = btrfs_balance(fs_info->balance_ctl, NULL);
3538
	}
I
Ilya Dryomov 已提交
3539 3540 3541

	mutex_unlock(&fs_info->balance_mutex);
	mutex_unlock(&fs_info->volume_mutex);
3542

I
Ilya Dryomov 已提交
3543 3544 3545
	return ret;
}

3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557
int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
{
	struct task_struct *tsk;

	spin_lock(&fs_info->balance_lock);
	if (!fs_info->balance_ctl) {
		spin_unlock(&fs_info->balance_lock);
		return 0;
	}
	spin_unlock(&fs_info->balance_lock);

	if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3558
		btrfs_info(fs_info, "force skipping balance");
3559 3560 3561 3562
		return 0;
	}

	tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3563
	return PTR_ERR_OR_ZERO(tsk);
3564 3565
}

3566
int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
I
Ilya Dryomov 已提交
3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583
{
	struct btrfs_balance_control *bctl;
	struct btrfs_balance_item *item;
	struct btrfs_disk_balance_args disk_bargs;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_key key;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	key.objectid = BTRFS_BALANCE_OBJECTID;
	key.type = BTRFS_BALANCE_ITEM_KEY;
	key.offset = 0;

3584
	ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
I
Ilya Dryomov 已提交
3585
	if (ret < 0)
3586
		goto out;
I
Ilya Dryomov 已提交
3587 3588
	if (ret > 0) { /* ret = -ENOENT; */
		ret = 0;
3589 3590 3591 3592 3593 3594 3595
		goto out;
	}

	bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
	if (!bctl) {
		ret = -ENOMEM;
		goto out;
I
Ilya Dryomov 已提交
3596 3597 3598 3599 3600
	}

	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);

3601 3602 3603
	bctl->fs_info = fs_info;
	bctl->flags = btrfs_balance_flags(leaf, item);
	bctl->flags |= BTRFS_BALANCE_RESUME;
I
Ilya Dryomov 已提交
3604 3605 3606 3607 3608 3609 3610 3611

	btrfs_balance_data(leaf, item, &disk_bargs);
	btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
	btrfs_balance_meta(leaf, item, &disk_bargs);
	btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
	btrfs_balance_sys(leaf, item, &disk_bargs);
	btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);

3612 3613
	WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));

3614 3615
	mutex_lock(&fs_info->volume_mutex);
	mutex_lock(&fs_info->balance_mutex);
I
Ilya Dryomov 已提交
3616

3617 3618 3619 3620
	set_balance_control(bctl);

	mutex_unlock(&fs_info->balance_mutex);
	mutex_unlock(&fs_info->volume_mutex);
I
Ilya Dryomov 已提交
3621 3622
out:
	btrfs_free_path(path);
3623 3624 3625
	return ret;
}

3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654
int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
{
	int ret = 0;

	mutex_lock(&fs_info->balance_mutex);
	if (!fs_info->balance_ctl) {
		mutex_unlock(&fs_info->balance_mutex);
		return -ENOTCONN;
	}

	if (atomic_read(&fs_info->balance_running)) {
		atomic_inc(&fs_info->balance_pause_req);
		mutex_unlock(&fs_info->balance_mutex);

		wait_event(fs_info->balance_wait_q,
			   atomic_read(&fs_info->balance_running) == 0);

		mutex_lock(&fs_info->balance_mutex);
		/* we are good with balance_ctl ripped off from under us */
		BUG_ON(atomic_read(&fs_info->balance_running));
		atomic_dec(&fs_info->balance_pause_req);
	} else {
		ret = -ENOTCONN;
	}

	mutex_unlock(&fs_info->balance_mutex);
	return ret;
}

3655 3656
int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
{
3657 3658 3659
	if (fs_info->sb->s_flags & MS_RDONLY)
		return -EROFS;

3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693
	mutex_lock(&fs_info->balance_mutex);
	if (!fs_info->balance_ctl) {
		mutex_unlock(&fs_info->balance_mutex);
		return -ENOTCONN;
	}

	atomic_inc(&fs_info->balance_cancel_req);
	/*
	 * if we are running just wait and return, balance item is
	 * deleted in btrfs_balance in this case
	 */
	if (atomic_read(&fs_info->balance_running)) {
		mutex_unlock(&fs_info->balance_mutex);
		wait_event(fs_info->balance_wait_q,
			   atomic_read(&fs_info->balance_running) == 0);
		mutex_lock(&fs_info->balance_mutex);
	} else {
		/* __cancel_balance needs volume_mutex */
		mutex_unlock(&fs_info->balance_mutex);
		mutex_lock(&fs_info->volume_mutex);
		mutex_lock(&fs_info->balance_mutex);

		if (fs_info->balance_ctl)
			__cancel_balance(fs_info);

		mutex_unlock(&fs_info->volume_mutex);
	}

	BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
	atomic_dec(&fs_info->balance_cancel_req);
	mutex_unlock(&fs_info->balance_mutex);
	return 0;
}

S
Stefan Behrens 已提交
3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705
static int btrfs_uuid_scan_kthread(void *data)
{
	struct btrfs_fs_info *fs_info = data;
	struct btrfs_root *root = fs_info->tree_root;
	struct btrfs_key key;
	struct btrfs_key max_key;
	struct btrfs_path *path = NULL;
	int ret = 0;
	struct extent_buffer *eb;
	int slot;
	struct btrfs_root_item root_item;
	u32 item_size;
3706
	struct btrfs_trans_handle *trans = NULL;
S
Stefan Behrens 已提交
3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	key.objectid = 0;
	key.type = BTRFS_ROOT_ITEM_KEY;
	key.offset = 0;

	max_key.objectid = (u64)-1;
	max_key.type = BTRFS_ROOT_ITEM_KEY;
	max_key.offset = (u64)-1;

	while (1) {
3723
		ret = btrfs_search_forward(root, &key, path, 0);
S
Stefan Behrens 已提交
3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746
		if (ret) {
			if (ret > 0)
				ret = 0;
			break;
		}

		if (key.type != BTRFS_ROOT_ITEM_KEY ||
		    (key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
		     key.objectid != BTRFS_FS_TREE_OBJECTID) ||
		    key.objectid > BTRFS_LAST_FREE_OBJECTID)
			goto skip;

		eb = path->nodes[0];
		slot = path->slots[0];
		item_size = btrfs_item_size_nr(eb, slot);
		if (item_size < sizeof(root_item))
			goto skip;

		read_extent_buffer(eb, &root_item,
				   btrfs_item_ptr_offset(eb, slot),
				   (int)sizeof(root_item));
		if (btrfs_root_refs(&root_item) == 0)
			goto skip;
3747 3748 3749 3750 3751 3752 3753

		if (!btrfs_is_empty_uuid(root_item.uuid) ||
		    !btrfs_is_empty_uuid(root_item.received_uuid)) {
			if (trans)
				goto update_tree;

			btrfs_release_path(path);
S
Stefan Behrens 已提交
3754 3755 3756 3757 3758 3759 3760 3761 3762
			/*
			 * 1 - subvol uuid item
			 * 1 - received_subvol uuid item
			 */
			trans = btrfs_start_transaction(fs_info->uuid_root, 2);
			if (IS_ERR(trans)) {
				ret = PTR_ERR(trans);
				break;
			}
3763 3764 3765 3766 3767 3768
			continue;
		} else {
			goto skip;
		}
update_tree:
		if (!btrfs_is_empty_uuid(root_item.uuid)) {
S
Stefan Behrens 已提交
3769 3770 3771 3772 3773
			ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
						  root_item.uuid,
						  BTRFS_UUID_KEY_SUBVOL,
						  key.objectid);
			if (ret < 0) {
3774
				btrfs_warn(fs_info, "uuid_tree_add failed %d",
S
Stefan Behrens 已提交
3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785
					ret);
				break;
			}
		}

		if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
			ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
						  root_item.received_uuid,
						 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
						  key.objectid);
			if (ret < 0) {
3786
				btrfs_warn(fs_info, "uuid_tree_add failed %d",
S
Stefan Behrens 已提交
3787 3788 3789 3790 3791
					ret);
				break;
			}
		}

3792
skip:
S
Stefan Behrens 已提交
3793 3794
		if (trans) {
			ret = btrfs_end_transaction(trans, fs_info->uuid_root);
3795
			trans = NULL;
S
Stefan Behrens 已提交
3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817
			if (ret)
				break;
		}

		btrfs_release_path(path);
		if (key.offset < (u64)-1) {
			key.offset++;
		} else if (key.type < BTRFS_ROOT_ITEM_KEY) {
			key.offset = 0;
			key.type = BTRFS_ROOT_ITEM_KEY;
		} else if (key.objectid < (u64)-1) {
			key.offset = 0;
			key.type = BTRFS_ROOT_ITEM_KEY;
			key.objectid++;
		} else {
			break;
		}
		cond_resched();
	}

out:
	btrfs_free_path(path);
3818 3819
	if (trans && !IS_ERR(trans))
		btrfs_end_transaction(trans, fs_info->uuid_root);
S
Stefan Behrens 已提交
3820
	if (ret)
3821
		btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret);
3822 3823
	else
		fs_info->update_uuid_tree_gen = 1;
S
Stefan Behrens 已提交
3824 3825 3826 3827
	up(&fs_info->uuid_tree_rescan_sem);
	return 0;
}

3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884
/*
 * Callback for btrfs_uuid_tree_iterate().
 * returns:
 * 0	check succeeded, the entry is not outdated.
 * < 0	if an error occured.
 * > 0	if the check failed, which means the caller shall remove the entry.
 */
static int btrfs_check_uuid_tree_entry(struct btrfs_fs_info *fs_info,
				       u8 *uuid, u8 type, u64 subid)
{
	struct btrfs_key key;
	int ret = 0;
	struct btrfs_root *subvol_root;

	if (type != BTRFS_UUID_KEY_SUBVOL &&
	    type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
		goto out;

	key.objectid = subid;
	key.type = BTRFS_ROOT_ITEM_KEY;
	key.offset = (u64)-1;
	subvol_root = btrfs_read_fs_root_no_name(fs_info, &key);
	if (IS_ERR(subvol_root)) {
		ret = PTR_ERR(subvol_root);
		if (ret == -ENOENT)
			ret = 1;
		goto out;
	}

	switch (type) {
	case BTRFS_UUID_KEY_SUBVOL:
		if (memcmp(uuid, subvol_root->root_item.uuid, BTRFS_UUID_SIZE))
			ret = 1;
		break;
	case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
		if (memcmp(uuid, subvol_root->root_item.received_uuid,
			   BTRFS_UUID_SIZE))
			ret = 1;
		break;
	}

out:
	return ret;
}

static int btrfs_uuid_rescan_kthread(void *data)
{
	struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
	int ret;

	/*
	 * 1st step is to iterate through the existing UUID tree and
	 * to delete all entries that contain outdated data.
	 * 2nd step is to add all missing entries to the UUID tree.
	 */
	ret = btrfs_uuid_tree_iterate(fs_info, btrfs_check_uuid_tree_entry);
	if (ret < 0) {
3885
		btrfs_warn(fs_info, "iterating uuid_tree failed %d", ret);
3886 3887 3888 3889 3890 3891
		up(&fs_info->uuid_tree_rescan_sem);
		return ret;
	}
	return btrfs_uuid_scan_kthread(data);
}

3892 3893 3894 3895 3896
int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *tree_root = fs_info->tree_root;
	struct btrfs_root *uuid_root;
S
Stefan Behrens 已提交
3897 3898
	struct task_struct *task;
	int ret;
3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917

	/*
	 * 1 - root node
	 * 1 - root item
	 */
	trans = btrfs_start_transaction(tree_root, 2);
	if (IS_ERR(trans))
		return PTR_ERR(trans);

	uuid_root = btrfs_create_tree(trans, fs_info,
				      BTRFS_UUID_TREE_OBJECTID);
	if (IS_ERR(uuid_root)) {
		btrfs_abort_transaction(trans, tree_root,
					PTR_ERR(uuid_root));
		return PTR_ERR(uuid_root);
	}

	fs_info->uuid_root = uuid_root;

S
Stefan Behrens 已提交
3918 3919 3920 3921 3922 3923 3924
	ret = btrfs_commit_transaction(trans, tree_root);
	if (ret)
		return ret;

	down(&fs_info->uuid_tree_rescan_sem);
	task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
	if (IS_ERR(task)) {
3925
		/* fs_info->update_uuid_tree_gen remains 0 in all error case */
3926
		btrfs_warn(fs_info, "failed to start uuid_scan task");
S
Stefan Behrens 已提交
3927 3928 3929 3930 3931
		up(&fs_info->uuid_tree_rescan_sem);
		return PTR_ERR(task);
	}

	return 0;
3932
}
S
Stefan Behrens 已提交
3933

3934 3935 3936 3937 3938 3939 3940 3941
int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
{
	struct task_struct *task;

	down(&fs_info->uuid_tree_rescan_sem);
	task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
	if (IS_ERR(task)) {
		/* fs_info->update_uuid_tree_gen remains 0 in all error case */
3942
		btrfs_warn(fs_info, "failed to start uuid_rescan task");
3943 3944 3945 3946 3947 3948 3949
		up(&fs_info->uuid_tree_rescan_sem);
		return PTR_ERR(task);
	}

	return 0;
}

3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966
/*
 * shrinking a device means finding all of the device extents past
 * the new size, and then following the back refs to the chunks.
 * The chunk relocation code actually frees the device extent
 */
int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = device->dev_root;
	struct btrfs_dev_extent *dev_extent = NULL;
	struct btrfs_path *path;
	u64 length;
	u64 chunk_tree;
	u64 chunk_objectid;
	u64 chunk_offset;
	int ret;
	int slot;
3967 3968
	int failed = 0;
	bool retried = false;
3969 3970
	struct extent_buffer *l;
	struct btrfs_key key;
3971
	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3972
	u64 old_total = btrfs_super_total_bytes(super_copy);
3973 3974
	u64 old_size = btrfs_device_get_total_bytes(device);
	u64 diff = old_size - new_size;
3975

3976 3977 3978
	if (device->is_tgtdev_for_dev_replace)
		return -EINVAL;

3979 3980 3981 3982 3983 3984
	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	path->reada = 2;

3985 3986
	lock_chunks(root);

3987
	btrfs_device_set_total_bytes(device, new_size);
3988
	if (device->writeable) {
Y
Yan Zheng 已提交
3989
		device->fs_devices->total_rw_bytes -= diff;
3990 3991 3992 3993
		spin_lock(&root->fs_info->free_chunk_lock);
		root->fs_info->free_chunk_space -= diff;
		spin_unlock(&root->fs_info->free_chunk_lock);
	}
3994
	unlock_chunks(root);
3995

3996
again:
3997 3998 3999 4000
	key.objectid = device->devid;
	key.offset = (u64)-1;
	key.type = BTRFS_DEV_EXTENT_KEY;

4001
	do {
4002 4003 4004 4005 4006 4007 4008 4009 4010
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret < 0)
			goto done;

		ret = btrfs_previous_item(root, path, 0, key.type);
		if (ret < 0)
			goto done;
		if (ret) {
			ret = 0;
4011
			btrfs_release_path(path);
4012
			break;
4013 4014 4015 4016 4017 4018
		}

		l = path->nodes[0];
		slot = path->slots[0];
		btrfs_item_key_to_cpu(l, &key, path->slots[0]);

4019
		if (key.objectid != device->devid) {
4020
			btrfs_release_path(path);
4021
			break;
4022
		}
4023 4024 4025 4026

		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
		length = btrfs_dev_extent_length(l, dev_extent);

4027
		if (key.offset + length <= new_size) {
4028
			btrfs_release_path(path);
4029
			break;
4030
		}
4031 4032 4033 4034

		chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
		chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
		chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
4035
		btrfs_release_path(path);
4036 4037 4038

		ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
					   chunk_offset);
4039
		if (ret && ret != -ENOSPC)
4040
			goto done;
4041 4042
		if (ret == -ENOSPC)
			failed++;
4043
	} while (key.offset-- > 0);
4044 4045 4046 4047 4048 4049 4050 4051 4052

	if (failed && !retried) {
		failed = 0;
		retried = true;
		goto again;
	} else if (failed && retried) {
		ret = -ENOSPC;
		lock_chunks(root);

4053
		btrfs_device_set_total_bytes(device, old_size);
4054 4055
		if (device->writeable)
			device->fs_devices->total_rw_bytes += diff;
4056 4057 4058
		spin_lock(&root->fs_info->free_chunk_lock);
		root->fs_info->free_chunk_space += diff;
		spin_unlock(&root->fs_info->free_chunk_lock);
4059 4060
		unlock_chunks(root);
		goto done;
4061 4062
	}

4063
	/* Shrinking succeeded, else we would be at "done". */
4064
	trans = btrfs_start_transaction(root, 0);
4065 4066 4067 4068 4069
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto done;
	}

4070
	lock_chunks(root);
4071
	btrfs_device_set_disk_total_bytes(device, new_size);
4072 4073 4074
	if (list_empty(&device->resized_list))
		list_add_tail(&device->resized_list,
			      &root->fs_info->fs_devices->resized_devices);
4075 4076 4077 4078

	WARN_ON(diff > old_total);
	btrfs_set_super_total_bytes(super_copy, old_total - diff);
	unlock_chunks(root);
M
Miao Xie 已提交
4079 4080 4081

	/* Now btrfs_update_device() will change the on-disk size. */
	ret = btrfs_update_device(trans, device);
4082
	btrfs_end_transaction(trans, root);
4083 4084 4085 4086 4087
done:
	btrfs_free_path(path);
	return ret;
}

4088
static int btrfs_add_system_chunk(struct btrfs_root *root,
4089 4090 4091
			   struct btrfs_key *key,
			   struct btrfs_chunk *chunk, int item_size)
{
4092
	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4093 4094 4095 4096
	struct btrfs_disk_key disk_key;
	u32 array_size;
	u8 *ptr;

4097
	lock_chunks(root);
4098
	array_size = btrfs_super_sys_array_size(super_copy);
4099
	if (array_size + item_size + sizeof(disk_key)
4100 4101
			> BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
		unlock_chunks(root);
4102
		return -EFBIG;
4103
	}
4104 4105 4106 4107 4108 4109 4110 4111

	ptr = super_copy->sys_chunk_array + array_size;
	btrfs_cpu_key_to_disk(&disk_key, key);
	memcpy(ptr, &disk_key, sizeof(disk_key));
	ptr += sizeof(disk_key);
	memcpy(ptr, chunk, item_size);
	item_size += sizeof(disk_key);
	btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
4112 4113
	unlock_chunks(root);

4114 4115 4116
	return 0;
}

4117 4118 4119 4120
/*
 * sort the devices in descending order by max_avail, total_avail
 */
static int btrfs_cmp_device_info(const void *a, const void *b)
4121
{
4122 4123
	const struct btrfs_device_info *di_a = a;
	const struct btrfs_device_info *di_b = b;
4124

4125
	if (di_a->max_avail > di_b->max_avail)
4126
		return -1;
4127
	if (di_a->max_avail < di_b->max_avail)
4128
		return 1;
4129 4130 4131 4132 4133
	if (di_a->total_avail > di_b->total_avail)
		return -1;
	if (di_a->total_avail < di_b->total_avail)
		return 1;
	return 0;
4134
}
4135

4136
static struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176
	[BTRFS_RAID_RAID10] = {
		.sub_stripes	= 2,
		.dev_stripes	= 1,
		.devs_max	= 0,	/* 0 == as many as possible */
		.devs_min	= 4,
		.devs_increment	= 2,
		.ncopies	= 2,
	},
	[BTRFS_RAID_RAID1] = {
		.sub_stripes	= 1,
		.dev_stripes	= 1,
		.devs_max	= 2,
		.devs_min	= 2,
		.devs_increment	= 2,
		.ncopies	= 2,
	},
	[BTRFS_RAID_DUP] = {
		.sub_stripes	= 1,
		.dev_stripes	= 2,
		.devs_max	= 1,
		.devs_min	= 1,
		.devs_increment	= 1,
		.ncopies	= 2,
	},
	[BTRFS_RAID_RAID0] = {
		.sub_stripes	= 1,
		.dev_stripes	= 1,
		.devs_max	= 0,
		.devs_min	= 2,
		.devs_increment	= 1,
		.ncopies	= 1,
	},
	[BTRFS_RAID_SINGLE] = {
		.sub_stripes	= 1,
		.dev_stripes	= 1,
		.devs_max	= 1,
		.devs_min	= 1,
		.devs_increment	= 1,
		.ncopies	= 1,
	},
4177 4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192
	[BTRFS_RAID_RAID5] = {
		.sub_stripes	= 1,
		.dev_stripes	= 1,
		.devs_max	= 0,
		.devs_min	= 2,
		.devs_increment	= 1,
		.ncopies	= 2,
	},
	[BTRFS_RAID_RAID6] = {
		.sub_stripes	= 1,
		.dev_stripes	= 1,
		.devs_max	= 0,
		.devs_min	= 3,
		.devs_increment	= 1,
		.ncopies	= 3,
	},
4193 4194
};

D
David Woodhouse 已提交
4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205
static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
{
	/* TODO allow them to set a preferred stripe size */
	return 64 * 1024;
}

static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
{
	if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
		return;

4206
	btrfs_set_fs_incompat(info, RAID56);
D
David Woodhouse 已提交
4207 4208
}

4209 4210 4211 4212 4213 4214 4215 4216 4217 4218
#define BTRFS_MAX_DEVS(r) ((BTRFS_LEAF_DATA_SIZE(r)		\
			- sizeof(struct btrfs_item)		\
			- sizeof(struct btrfs_chunk))		\
			/ sizeof(struct btrfs_stripe) + 1)

#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
				- 2 * sizeof(struct btrfs_disk_key)	\
				- 2 * sizeof(struct btrfs_chunk))	\
				/ sizeof(struct btrfs_stripe) + 1)

4219
static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4220 4221
			       struct btrfs_root *extent_root, u64 start,
			       u64 type)
4222
{
4223 4224 4225 4226 4227 4228 4229 4230 4231
	struct btrfs_fs_info *info = extent_root->fs_info;
	struct btrfs_fs_devices *fs_devices = info->fs_devices;
	struct list_head *cur;
	struct map_lookup *map = NULL;
	struct extent_map_tree *em_tree;
	struct extent_map *em;
	struct btrfs_device_info *devices_info = NULL;
	u64 total_avail;
	int num_stripes;	/* total number of stripes to allocate */
D
David Woodhouse 已提交
4232 4233
	int data_stripes;	/* number of stripes that count for
				   block group size */
4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244
	int sub_stripes;	/* sub_stripes info for map */
	int dev_stripes;	/* stripes per dev */
	int devs_max;		/* max devs to use */
	int devs_min;		/* min devs needed */
	int devs_increment;	/* ndevs has to be a multiple of this */
	int ncopies;		/* how many copies to data has */
	int ret;
	u64 max_stripe_size;
	u64 max_chunk_size;
	u64 stripe_size;
	u64 num_bytes;
D
David Woodhouse 已提交
4245
	u64 raid_stripe_len = BTRFS_STRIPE_LEN;
4246 4247 4248
	int ndevs;
	int i;
	int j;
4249
	int index;
4250

4251
	BUG_ON(!alloc_profile_is_valid(type, 0));
4252

4253 4254
	if (list_empty(&fs_devices->alloc_list))
		return -ENOSPC;
4255

4256
	index = __get_raid_index(type);
4257

4258 4259 4260 4261 4262 4263
	sub_stripes = btrfs_raid_array[index].sub_stripes;
	dev_stripes = btrfs_raid_array[index].dev_stripes;
	devs_max = btrfs_raid_array[index].devs_max;
	devs_min = btrfs_raid_array[index].devs_min;
	devs_increment = btrfs_raid_array[index].devs_increment;
	ncopies = btrfs_raid_array[index].ncopies;
4264

4265
	if (type & BTRFS_BLOCK_GROUP_DATA) {
4266 4267
		max_stripe_size = 1024 * 1024 * 1024;
		max_chunk_size = 10 * max_stripe_size;
4268 4269
		if (!devs_max)
			devs_max = BTRFS_MAX_DEVS(info->chunk_root);
4270
	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
4271 4272 4273 4274 4275
		/* for larger filesystems, use larger metadata chunks */
		if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
			max_stripe_size = 1024 * 1024 * 1024;
		else
			max_stripe_size = 256 * 1024 * 1024;
4276
		max_chunk_size = max_stripe_size;
4277 4278
		if (!devs_max)
			devs_max = BTRFS_MAX_DEVS(info->chunk_root);
4279
	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
C
Chris Mason 已提交
4280
		max_stripe_size = 32 * 1024 * 1024;
4281
		max_chunk_size = 2 * max_stripe_size;
4282 4283
		if (!devs_max)
			devs_max = BTRFS_MAX_DEVS_SYS_CHUNK;
4284
	} else {
4285
		btrfs_err(info, "invalid chunk type 0x%llx requested",
4286 4287
		       type);
		BUG_ON(1);
4288 4289
	}

Y
Yan Zheng 已提交
4290 4291 4292
	/* we don't want a chunk larger than 10% of writeable space */
	max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
			     max_chunk_size);
4293

4294 4295 4296 4297
	devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
			       GFP_NOFS);
	if (!devices_info)
		return -ENOMEM;
4298

4299
	cur = fs_devices->alloc_list.next;
4300

4301
	/*
4302 4303
	 * in the first pass through the devices list, we gather information
	 * about the available holes on each device.
4304
	 */
4305 4306 4307 4308 4309
	ndevs = 0;
	while (cur != &fs_devices->alloc_list) {
		struct btrfs_device *device;
		u64 max_avail;
		u64 dev_offset;
4310

4311
		device = list_entry(cur, struct btrfs_device, dev_alloc_list);
4312

4313
		cur = cur->next;
4314

4315
		if (!device->writeable) {
J
Julia Lawall 已提交
4316
			WARN(1, KERN_ERR
4317
			       "BTRFS: read-only device in alloc_list\n");
4318 4319
			continue;
		}
4320

4321 4322
		if (!device->in_fs_metadata ||
		    device->is_tgtdev_for_dev_replace)
4323
			continue;
4324

4325 4326 4327 4328
		if (device->total_bytes > device->bytes_used)
			total_avail = device->total_bytes - device->bytes_used;
		else
			total_avail = 0;
4329 4330 4331 4332

		/* If there is no space on this device, skip it. */
		if (total_avail == 0)
			continue;
4333

4334
		ret = find_free_dev_extent(trans, device,
4335 4336 4337 4338
					   max_stripe_size * dev_stripes,
					   &dev_offset, &max_avail);
		if (ret && ret != -ENOSPC)
			goto error;
4339

4340 4341
		if (ret == 0)
			max_avail = max_stripe_size * dev_stripes;
4342

4343 4344
		if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
			continue;
4345

4346 4347 4348 4349 4350
		if (ndevs == fs_devices->rw_devices) {
			WARN(1, "%s: found more than %llu devices\n",
			     __func__, fs_devices->rw_devices);
			break;
		}
4351 4352 4353 4354 4355 4356
		devices_info[ndevs].dev_offset = dev_offset;
		devices_info[ndevs].max_avail = max_avail;
		devices_info[ndevs].total_avail = total_avail;
		devices_info[ndevs].dev = device;
		++ndevs;
	}
4357

4358 4359 4360 4361 4362
	/*
	 * now sort the devices by hole size / available space
	 */
	sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
	     btrfs_cmp_device_info, NULL);
4363

4364 4365
	/* round down to number of usable stripes */
	ndevs -= ndevs % devs_increment;
4366

4367 4368 4369
	if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
		ret = -ENOSPC;
		goto error;
4370
	}
4371

4372 4373 4374 4375 4376 4377 4378 4379
	if (devs_max && ndevs > devs_max)
		ndevs = devs_max;
	/*
	 * the primary goal is to maximize the number of stripes, so use as many
	 * devices as possible, even if the stripes are not maximum sized.
	 */
	stripe_size = devices_info[ndevs-1].max_avail;
	num_stripes = ndevs * dev_stripes;
4380

D
David Woodhouse 已提交
4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396
	/*
	 * this will have to be fixed for RAID1 and RAID10 over
	 * more drives
	 */
	data_stripes = num_stripes / ncopies;

	if (type & BTRFS_BLOCK_GROUP_RAID5) {
		raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
				 btrfs_super_stripesize(info->super_copy));
		data_stripes = num_stripes - 1;
	}
	if (type & BTRFS_BLOCK_GROUP_RAID6) {
		raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
				 btrfs_super_stripesize(info->super_copy));
		data_stripes = num_stripes - 2;
	}
4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 4410 4411 4412 4413 4414 4415 4416 4417

	/*
	 * Use the number of data stripes to figure out how big this chunk
	 * is really going to be in terms of logical address space,
	 * and compare that answer with the max chunk size
	 */
	if (stripe_size * data_stripes > max_chunk_size) {
		u64 mask = (1ULL << 24) - 1;
		stripe_size = max_chunk_size;
		do_div(stripe_size, data_stripes);

		/* bump the answer up to a 16MB boundary */
		stripe_size = (stripe_size + mask) & ~mask;

		/* but don't go higher than the limits we found
		 * while searching for free extents
		 */
		if (stripe_size > devices_info[ndevs-1].max_avail)
			stripe_size = devices_info[ndevs-1].max_avail;
	}

4418
	do_div(stripe_size, dev_stripes);
4419 4420

	/* align to BTRFS_STRIPE_LEN */
D
David Woodhouse 已提交
4421 4422
	do_div(stripe_size, raid_stripe_len);
	stripe_size *= raid_stripe_len;
4423 4424 4425 4426 4427 4428 4429

	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
	if (!map) {
		ret = -ENOMEM;
		goto error;
	}
	map->num_stripes = num_stripes;
4430

4431 4432 4433 4434 4435 4436
	for (i = 0; i < ndevs; ++i) {
		for (j = 0; j < dev_stripes; ++j) {
			int s = i * dev_stripes + j;
			map->stripes[s].dev = devices_info[i].dev;
			map->stripes[s].physical = devices_info[i].dev_offset +
						   j * stripe_size;
4437 4438
		}
	}
Y
Yan Zheng 已提交
4439
	map->sector_size = extent_root->sectorsize;
D
David Woodhouse 已提交
4440 4441 4442
	map->stripe_len = raid_stripe_len;
	map->io_align = raid_stripe_len;
	map->io_width = raid_stripe_len;
Y
Yan Zheng 已提交
4443 4444
	map->type = type;
	map->sub_stripes = sub_stripes;
4445

D
David Woodhouse 已提交
4446
	num_bytes = stripe_size * data_stripes;
4447

4448
	trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
4449

4450
	em = alloc_extent_map();
Y
Yan Zheng 已提交
4451
	if (!em) {
4452
		kfree(map);
4453 4454
		ret = -ENOMEM;
		goto error;
4455
	}
4456
	set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
Y
Yan Zheng 已提交
4457 4458
	em->bdev = (struct block_device *)map;
	em->start = start;
4459
	em->len = num_bytes;
Y
Yan Zheng 已提交
4460 4461
	em->block_start = 0;
	em->block_len = em->len;
4462
	em->orig_block_len = stripe_size;
4463

Y
Yan Zheng 已提交
4464
	em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4465
	write_lock(&em_tree->lock);
J
Josef Bacik 已提交
4466
	ret = add_extent_mapping(em_tree, em, 0);
4467 4468 4469 4470
	if (!ret) {
		list_add_tail(&em->list, &trans->transaction->pending_chunks);
		atomic_inc(&em->refs);
	}
4471
	write_unlock(&em_tree->lock);
4472 4473
	if (ret) {
		free_extent_map(em);
4474
		goto error;
4475
	}
4476

4477 4478 4479
	ret = btrfs_make_block_group(trans, extent_root, 0, type,
				     BTRFS_FIRST_CHUNK_TREE_OBJECTID,
				     start, num_bytes);
4480 4481
	if (ret)
		goto error_del_extent;
Y
Yan Zheng 已提交
4482

4483 4484 4485 4486
	for (i = 0; i < map->num_stripes; i++) {
		num_bytes = map->stripes[i].dev->bytes_used + stripe_size;
		btrfs_device_set_bytes_used(map->stripes[i].dev, num_bytes);
	}
4487

4488 4489 4490 4491 4492
	spin_lock(&extent_root->fs_info->free_chunk_lock);
	extent_root->fs_info->free_chunk_space -= (stripe_size *
						   map->num_stripes);
	spin_unlock(&extent_root->fs_info->free_chunk_lock);

4493
	free_extent_map(em);
D
David Woodhouse 已提交
4494 4495
	check_raid56_incompat_flag(extent_root->fs_info, type);

4496
	kfree(devices_info);
Y
Yan Zheng 已提交
4497
	return 0;
4498

4499
error_del_extent:
4500 4501 4502 4503 4504 4505 4506 4507
	write_lock(&em_tree->lock);
	remove_extent_mapping(em_tree, em);
	write_unlock(&em_tree->lock);

	/* One for our allocation */
	free_extent_map(em);
	/* One for the tree reference */
	free_extent_map(em);
4508 4509 4510
error:
	kfree(devices_info);
	return ret;
Y
Yan Zheng 已提交
4511 4512
}

4513
int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
Y
Yan Zheng 已提交
4514
				struct btrfs_root *extent_root,
4515
				u64 chunk_offset, u64 chunk_size)
Y
Yan Zheng 已提交
4516 4517 4518 4519 4520 4521
{
	struct btrfs_key key;
	struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
	struct btrfs_device *device;
	struct btrfs_chunk *chunk;
	struct btrfs_stripe *stripe;
4522 4523 4524 4525 4526 4527 4528
	struct extent_map_tree *em_tree;
	struct extent_map *em;
	struct map_lookup *map;
	size_t item_size;
	u64 dev_offset;
	u64 stripe_size;
	int i = 0;
Y
Yan Zheng 已提交
4529 4530
	int ret;

4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543
	em_tree = &extent_root->fs_info->mapping_tree.map_tree;
	read_lock(&em_tree->lock);
	em = lookup_extent_mapping(em_tree, chunk_offset, chunk_size);
	read_unlock(&em_tree->lock);

	if (!em) {
		btrfs_crit(extent_root->fs_info, "unable to find logical "
			   "%Lu len %Lu", chunk_offset, chunk_size);
		return -EINVAL;
	}

	if (em->start != chunk_offset || em->len != chunk_size) {
		btrfs_crit(extent_root->fs_info, "found a bad mapping, wanted"
4544
			  " %Lu-%Lu, found %Lu-%Lu", chunk_offset,
4545 4546 4547 4548 4549 4550 4551 4552 4553
			  chunk_size, em->start, em->len);
		free_extent_map(em);
		return -EINVAL;
	}

	map = (struct map_lookup *)em->bdev;
	item_size = btrfs_chunk_item_size(map->num_stripes);
	stripe_size = em->orig_block_len;

Y
Yan Zheng 已提交
4554
	chunk = kzalloc(item_size, GFP_NOFS);
4555 4556 4557 4558 4559 4560 4561 4562
	if (!chunk) {
		ret = -ENOMEM;
		goto out;
	}

	for (i = 0; i < map->num_stripes; i++) {
		device = map->stripes[i].dev;
		dev_offset = map->stripes[i].physical;
Y
Yan Zheng 已提交
4563

4564
		ret = btrfs_update_device(trans, device);
4565
		if (ret)
4566 4567 4568 4569 4570 4571 4572 4573
			goto out;
		ret = btrfs_alloc_dev_extent(trans, device,
					     chunk_root->root_key.objectid,
					     BTRFS_FIRST_CHUNK_TREE_OBJECTID,
					     chunk_offset, dev_offset,
					     stripe_size);
		if (ret)
			goto out;
Y
Yan Zheng 已提交
4574 4575 4576
	}

	stripe = &chunk->stripe;
4577 4578 4579
	for (i = 0; i < map->num_stripes; i++) {
		device = map->stripes[i].dev;
		dev_offset = map->stripes[i].physical;
4580

4581 4582 4583
		btrfs_set_stack_stripe_devid(stripe, device->devid);
		btrfs_set_stack_stripe_offset(stripe, dev_offset);
		memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
Y
Yan Zheng 已提交
4584
		stripe++;
4585 4586
	}

Y
Yan Zheng 已提交
4587
	btrfs_set_stack_chunk_length(chunk, chunk_size);
4588
	btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
Y
Yan Zheng 已提交
4589 4590 4591 4592 4593
	btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
	btrfs_set_stack_chunk_type(chunk, map->type);
	btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
	btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
	btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4594
	btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
Y
Yan Zheng 已提交
4595
	btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4596

Y
Yan Zheng 已提交
4597 4598 4599
	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
	key.type = BTRFS_CHUNK_ITEM_KEY;
	key.offset = chunk_offset;
4600

Y
Yan Zheng 已提交
4601
	ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4602 4603 4604 4605 4606
	if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
		/*
		 * TODO: Cleanup of inserted chunk root in case of
		 * failure.
		 */
4607
		ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
Y
Yan Zheng 已提交
4608
					     item_size);
4609
	}
4610

4611
out:
4612
	kfree(chunk);
4613
	free_extent_map(em);
4614
	return ret;
Y
Yan Zheng 已提交
4615
}
4616

Y
Yan Zheng 已提交
4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628
/*
 * Chunk allocation falls into two parts. The first part does works
 * that make the new allocated chunk useable, but not do any operation
 * that modifies the chunk tree. The second part does the works that
 * require modifying the chunk tree. This division is important for the
 * bootstrap process of adding storage to a seed btrfs.
 */
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
		      struct btrfs_root *extent_root, u64 type)
{
	u64 chunk_offset;

4629 4630
	chunk_offset = find_next_chunk(extent_root->fs_info);
	return __btrfs_alloc_chunk(trans, extent_root, chunk_offset, type);
Y
Yan Zheng 已提交
4631 4632
}

C
Chris Mason 已提交
4633
static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
Y
Yan Zheng 已提交
4634 4635 4636 4637 4638 4639 4640 4641 4642 4643
					 struct btrfs_root *root,
					 struct btrfs_device *device)
{
	u64 chunk_offset;
	u64 sys_chunk_offset;
	u64 alloc_profile;
	struct btrfs_fs_info *fs_info = root->fs_info;
	struct btrfs_root *extent_root = fs_info->extent_root;
	int ret;

4644
	chunk_offset = find_next_chunk(fs_info);
4645
	alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4646 4647
	ret = __btrfs_alloc_chunk(trans, extent_root, chunk_offset,
				  alloc_profile);
4648 4649
	if (ret)
		return ret;
Y
Yan Zheng 已提交
4650

4651
	sys_chunk_offset = find_next_chunk(root->fs_info);
4652
	alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4653 4654
	ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
				  alloc_profile);
4655
	return ret;
Y
Yan Zheng 已提交
4656 4657
}

4658 4659 4660 4661 4662 4663 4664 4665 4666 4667 4668 4669 4670
static inline int btrfs_chunk_max_errors(struct map_lookup *map)
{
	int max_errors;

	if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
			 BTRFS_BLOCK_GROUP_RAID10 |
			 BTRFS_BLOCK_GROUP_RAID5 |
			 BTRFS_BLOCK_GROUP_DUP)) {
		max_errors = 1;
	} else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
		max_errors = 2;
	} else {
		max_errors = 0;
4671
	}
Y
Yan Zheng 已提交
4672

4673
	return max_errors;
Y
Yan Zheng 已提交
4674 4675 4676 4677 4678 4679 4680 4681
}

int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
{
	struct extent_map *em;
	struct map_lookup *map;
	struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
	int readonly = 0;
4682
	int miss_ndevs = 0;
Y
Yan Zheng 已提交
4683 4684
	int i;

4685
	read_lock(&map_tree->map_tree.lock);
Y
Yan Zheng 已提交
4686
	em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4687
	read_unlock(&map_tree->map_tree.lock);
Y
Yan Zheng 已提交
4688 4689 4690 4691 4692
	if (!em)
		return 1;

	map = (struct map_lookup *)em->bdev;
	for (i = 0; i < map->num_stripes; i++) {
4693 4694 4695 4696 4697
		if (map->stripes[i].dev->missing) {
			miss_ndevs++;
			continue;
		}

Y
Yan Zheng 已提交
4698 4699
		if (!map->stripes[i].dev->writeable) {
			readonly = 1;
4700
			goto end;
Y
Yan Zheng 已提交
4701 4702
		}
	}
4703 4704 4705 4706 4707 4708 4709 4710 4711

	/*
	 * If the number of missing devices is larger than max errors,
	 * we can not write the data into that chunk successfully, so
	 * set it readonly.
	 */
	if (miss_ndevs > btrfs_chunk_max_errors(map))
		readonly = 1;
end:
4712
	free_extent_map(em);
Y
Yan Zheng 已提交
4713
	return readonly;
4714 4715 4716 4717
}

void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
{
4718
	extent_map_tree_init(&tree->map_tree);
4719 4720 4721 4722 4723 4724
}

void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
{
	struct extent_map *em;

C
Chris Mason 已提交
4725
	while (1) {
4726
		write_lock(&tree->map_tree.lock);
4727 4728 4729
		em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
		if (em)
			remove_extent_mapping(&tree->map_tree, em);
4730
		write_unlock(&tree->map_tree.lock);
4731 4732 4733 4734 4735 4736 4737 4738 4739
		if (!em)
			break;
		/* once for us */
		free_extent_map(em);
		/* once for the tree */
		free_extent_map(em);
	}
}

4740
int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4741
{
4742
	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4743 4744 4745 4746 4747
	struct extent_map *em;
	struct map_lookup *map;
	struct extent_map_tree *em_tree = &map_tree->map_tree;
	int ret;

4748
	read_lock(&em_tree->lock);
4749
	em = lookup_extent_mapping(em_tree, logical, len);
4750
	read_unlock(&em_tree->lock);
4751

4752 4753 4754 4755 4756 4757
	/*
	 * We could return errors for these cases, but that could get ugly and
	 * we'd probably do the same thing which is just not do anything else
	 * and exit, so return 1 so the callers don't try to use other copies.
	 */
	if (!em) {
4758
		btrfs_crit(fs_info, "No mapping for %Lu-%Lu", logical,
4759 4760 4761 4762 4763
			    logical+len);
		return 1;
	}

	if (em->start > logical || em->start + em->len < logical) {
4764
		btrfs_crit(fs_info, "Invalid mapping for %Lu-%Lu, got "
4765
			    "%Lu-%Lu", logical, logical+len, em->start,
4766
			    em->start + em->len);
4767
		free_extent_map(em);
4768 4769 4770
		return 1;
	}

4771 4772 4773
	map = (struct map_lookup *)em->bdev;
	if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
		ret = map->num_stripes;
C
Chris Mason 已提交
4774 4775
	else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
		ret = map->sub_stripes;
D
David Woodhouse 已提交
4776 4777 4778 4779
	else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
		ret = 2;
	else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
		ret = 3;
4780 4781 4782
	else
		ret = 1;
	free_extent_map(em);
4783 4784 4785 4786 4787 4788

	btrfs_dev_replace_lock(&fs_info->dev_replace);
	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
		ret++;
	btrfs_dev_replace_unlock(&fs_info->dev_replace);

4789 4790 4791
	return ret;
}

D
David Woodhouse 已提交
4792 4793 4794 4795 4796 4797 4798 4799 4800 4801 4802 4803 4804 4805 4806 4807 4808 4809 4810 4811 4812 4813 4814 4815 4816 4817 4818 4819 4820 4821 4822 4823 4824 4825 4826 4827 4828 4829 4830 4831 4832 4833 4834 4835 4836 4837
unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
				    struct btrfs_mapping_tree *map_tree,
				    u64 logical)
{
	struct extent_map *em;
	struct map_lookup *map;
	struct extent_map_tree *em_tree = &map_tree->map_tree;
	unsigned long len = root->sectorsize;

	read_lock(&em_tree->lock);
	em = lookup_extent_mapping(em_tree, logical, len);
	read_unlock(&em_tree->lock);
	BUG_ON(!em);

	BUG_ON(em->start > logical || em->start + em->len < logical);
	map = (struct map_lookup *)em->bdev;
	if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
			 BTRFS_BLOCK_GROUP_RAID6)) {
		len = map->stripe_len * nr_data_stripes(map);
	}
	free_extent_map(em);
	return len;
}

int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
			   u64 logical, u64 len, int mirror_num)
{
	struct extent_map *em;
	struct map_lookup *map;
	struct extent_map_tree *em_tree = &map_tree->map_tree;
	int ret = 0;

	read_lock(&em_tree->lock);
	em = lookup_extent_mapping(em_tree, logical, len);
	read_unlock(&em_tree->lock);
	BUG_ON(!em);

	BUG_ON(em->start > logical || em->start + em->len < logical);
	map = (struct map_lookup *)em->bdev;
	if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
			 BTRFS_BLOCK_GROUP_RAID6))
		ret = 1;
	free_extent_map(em);
	return ret;
}

4838 4839 4840
static int find_live_mirror(struct btrfs_fs_info *fs_info,
			    struct map_lookup *map, int first, int num,
			    int optimal, int dev_replace_is_ongoing)
4841 4842
{
	int i;
4843 4844 4845 4846 4847 4848 4849 4850 4851 4852 4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864 4865 4866
	int tolerance;
	struct btrfs_device *srcdev;

	if (dev_replace_is_ongoing &&
	    fs_info->dev_replace.cont_reading_from_srcdev_mode ==
	     BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
		srcdev = fs_info->dev_replace.srcdev;
	else
		srcdev = NULL;

	/*
	 * try to avoid the drive that is the source drive for a
	 * dev-replace procedure, only choose it if no other non-missing
	 * mirror is available
	 */
	for (tolerance = 0; tolerance < 2; tolerance++) {
		if (map->stripes[optimal].dev->bdev &&
		    (tolerance || map->stripes[optimal].dev != srcdev))
			return optimal;
		for (i = first; i < first + num; i++) {
			if (map->stripes[i].dev->bdev &&
			    (tolerance || map->stripes[i].dev != srcdev))
				return i;
		}
4867
	}
4868

4869 4870 4871 4872 4873 4874
	/* we couldn't find one that doesn't fail.  Just return something
	 * and the io error handling code will clean up eventually
	 */
	return optimal;
}

D
David Woodhouse 已提交
4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899 4900 4901 4902 4903
static inline int parity_smaller(u64 a, u64 b)
{
	return a > b;
}

/* Bubble-sort the stripe set to put the parity/syndrome stripes last */
static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
{
	struct btrfs_bio_stripe s;
	int i;
	u64 l;
	int again = 1;

	while (again) {
		again = 0;
		for (i = 0; i < bbio->num_stripes - 1; i++) {
			if (parity_smaller(raid_map[i], raid_map[i+1])) {
				s = bbio->stripes[i];
				l = raid_map[i];
				bbio->stripes[i] = bbio->stripes[i+1];
				raid_map[i] = raid_map[i+1];
				bbio->stripes[i+1] = s;
				raid_map[i+1] = l;
				again = 1;
			}
		}
	}
}

4904
static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4905
			     u64 logical, u64 *length,
4906
			     struct btrfs_bio **bbio_ret,
D
David Woodhouse 已提交
4907
			     int mirror_num, u64 **raid_map_ret)
4908 4909 4910
{
	struct extent_map *em;
	struct map_lookup *map;
4911
	struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4912 4913
	struct extent_map_tree *em_tree = &map_tree->map_tree;
	u64 offset;
4914
	u64 stripe_offset;
4915
	u64 stripe_end_offset;
4916
	u64 stripe_nr;
4917 4918
	u64 stripe_nr_orig;
	u64 stripe_nr_end;
D
David Woodhouse 已提交
4919 4920
	u64 stripe_len;
	u64 *raid_map = NULL;
4921
	int stripe_index;
4922
	int i;
L
Li Zefan 已提交
4923
	int ret = 0;
4924
	int num_stripes;
4925
	int max_errors = 0;
4926
	struct btrfs_bio *bbio = NULL;
4927 4928 4929
	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
	int dev_replace_is_ongoing = 0;
	int num_alloc_stripes;
4930 4931
	int patch_the_first_stripe_for_dev_replace = 0;
	u64 physical_to_patch_in_first_stripe = 0;
D
David Woodhouse 已提交
4932
	u64 raid56_full_stripe_start = (u64)-1;
4933

4934
	read_lock(&em_tree->lock);
4935
	em = lookup_extent_mapping(em_tree, logical, *length);
4936
	read_unlock(&em_tree->lock);
4937

4938
	if (!em) {
4939
		btrfs_crit(fs_info, "unable to find logical %llu len %llu",
4940
			logical, *length);
4941 4942 4943 4944 4945
		return -EINVAL;
	}

	if (em->start > logical || em->start + em->len < logical) {
		btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "
4946
			   "found %Lu-%Lu", logical, em->start,
4947
			   em->start + em->len);
4948
		free_extent_map(em);
4949
		return -EINVAL;
4950
	}
4951 4952 4953

	map = (struct map_lookup *)em->bdev;
	offset = logical - em->start;
4954

D
David Woodhouse 已提交
4955
	stripe_len = map->stripe_len;
4956 4957 4958 4959 4960
	stripe_nr = offset;
	/*
	 * stripe_nr counts the total number of stripes we have to stride
	 * to get to this block
	 */
D
David Woodhouse 已提交
4961
	do_div(stripe_nr, stripe_len);
4962

D
David Woodhouse 已提交
4963
	stripe_offset = stripe_nr * stripe_len;
4964 4965 4966 4967 4968
	BUG_ON(offset < stripe_offset);

	/* stripe_offset is the offset of this block in its stripe*/
	stripe_offset = offset - stripe_offset;

D
David Woodhouse 已提交
4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979 4980 4981 4982 4983 4984 4985 4986 4987
	/* if we're here for raid56, we need to know the stripe aligned start */
	if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
		unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
		raid56_full_stripe_start = offset;

		/* allow a write of a full stripe, but make sure we don't
		 * allow straddling of stripes
		 */
		do_div(raid56_full_stripe_start, full_stripe_len);
		raid56_full_stripe_start *= full_stripe_len;
	}

	if (rw & REQ_DISCARD) {
		/* we don't discard raid56 yet */
		if (map->type &
		    (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
			ret = -EOPNOTSUPP;
			goto out;
		}
4988
		*length = min_t(u64, em->len - offset, *length);
D
David Woodhouse 已提交
4989 4990 4991 4992 4993 4994 4995 4996 4997 4998 4999 5000 5001 5002
	} else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
		u64 max_len;
		/* For writes to RAID[56], allow a full stripeset across all disks.
		   For other RAID types and for RAID[56] reads, just allow a single
		   stripe (on a single disk). */
		if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
		    (rw & REQ_WRITE)) {
			max_len = stripe_len * nr_data_stripes(map) -
				(offset - raid56_full_stripe_start);
		} else {
			/* we limit the length of each bio to what fits in a stripe */
			max_len = stripe_len - stripe_offset;
		}
		*length = min_t(u64, em->len - offset, max_len);
5003 5004 5005
	} else {
		*length = em->len - offset;
	}
5006

D
David Woodhouse 已提交
5007 5008
	/* This is for when we're called from btrfs_merge_bio_hook() and all
	   it cares about is the length */
5009
	if (!bbio_ret)
5010 5011
		goto out;

5012 5013 5014 5015 5016
	btrfs_dev_replace_lock(dev_replace);
	dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
	if (!dev_replace_is_ongoing)
		btrfs_dev_replace_unlock(dev_replace);

5017 5018 5019 5020 5021 5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040
	if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
	    !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
	    dev_replace->tgtdev != NULL) {
		/*
		 * in dev-replace case, for repair case (that's the only
		 * case where the mirror is selected explicitly when
		 * calling btrfs_map_block), blocks left of the left cursor
		 * can also be read from the target drive.
		 * For REQ_GET_READ_MIRRORS, the target drive is added as
		 * the last one to the array of stripes. For READ, it also
		 * needs to be supported using the same mirror number.
		 * If the requested block is not left of the left cursor,
		 * EIO is returned. This can happen because btrfs_num_copies()
		 * returns one more in the dev-replace case.
		 */
		u64 tmp_length = *length;
		struct btrfs_bio *tmp_bbio = NULL;
		int tmp_num_stripes;
		u64 srcdev_devid = dev_replace->srcdev->devid;
		int index_srcdev = 0;
		int found = 0;
		u64 physical_of_found = 0;

		ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
D
David Woodhouse 已提交
5041
			     logical, &tmp_length, &tmp_bbio, 0, NULL);
5042 5043 5044 5045 5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067 5068 5069 5070 5071 5072 5073 5074 5075 5076 5077 5078 5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 5098
		if (ret) {
			WARN_ON(tmp_bbio != NULL);
			goto out;
		}

		tmp_num_stripes = tmp_bbio->num_stripes;
		if (mirror_num > tmp_num_stripes) {
			/*
			 * REQ_GET_READ_MIRRORS does not contain this
			 * mirror, that means that the requested area
			 * is not left of the left cursor
			 */
			ret = -EIO;
			kfree(tmp_bbio);
			goto out;
		}

		/*
		 * process the rest of the function using the mirror_num
		 * of the source drive. Therefore look it up first.
		 * At the end, patch the device pointer to the one of the
		 * target drive.
		 */
		for (i = 0; i < tmp_num_stripes; i++) {
			if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
				/*
				 * In case of DUP, in order to keep it
				 * simple, only add the mirror with the
				 * lowest physical address
				 */
				if (found &&
				    physical_of_found <=
				     tmp_bbio->stripes[i].physical)
					continue;
				index_srcdev = i;
				found = 1;
				physical_of_found =
					tmp_bbio->stripes[i].physical;
			}
		}

		if (found) {
			mirror_num = index_srcdev + 1;
			patch_the_first_stripe_for_dev_replace = 1;
			physical_to_patch_in_first_stripe = physical_of_found;
		} else {
			WARN_ON(1);
			ret = -EIO;
			kfree(tmp_bbio);
			goto out;
		}

		kfree(tmp_bbio);
	} else if (mirror_num > map->num_stripes) {
		mirror_num = 0;
	}

5099
	num_stripes = 1;
5100
	stripe_index = 0;
5101
	stripe_nr_orig = stripe_nr;
5102
	stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
5103 5104 5105
	do_div(stripe_nr_end, map->stripe_len);
	stripe_end_offset = stripe_nr_end * map->stripe_len -
			    (offset + *length);
D
David Woodhouse 已提交
5106

5107 5108 5109 5110 5111
	if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
		if (rw & REQ_DISCARD)
			num_stripes = min_t(u64, map->num_stripes,
					    stripe_nr_end - stripe_nr_orig);
		stripe_index = do_div(stripe_nr, map->num_stripes);
5112 5113
		if (!(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)))
			mirror_num = 1;
5114
	} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
5115
		if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
5116
			num_stripes = map->num_stripes;
5117
		else if (mirror_num)
5118
			stripe_index = mirror_num - 1;
5119
		else {
5120
			stripe_index = find_live_mirror(fs_info, map, 0,
5121
					    map->num_stripes,
5122 5123
					    current->pid % map->num_stripes,
					    dev_replace_is_ongoing);
5124
			mirror_num = stripe_index + 1;
5125
		}
5126

5127
	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
5128
		if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
5129
			num_stripes = map->num_stripes;
5130
		} else if (mirror_num) {
5131
			stripe_index = mirror_num - 1;
5132 5133 5134
		} else {
			mirror_num = 1;
		}
5135

C
Chris Mason 已提交
5136 5137 5138 5139 5140 5141
	} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
		int factor = map->num_stripes / map->sub_stripes;

		stripe_index = do_div(stripe_nr, factor);
		stripe_index *= map->sub_stripes;

5142
		if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
5143
			num_stripes = map->sub_stripes;
5144 5145 5146 5147
		else if (rw & REQ_DISCARD)
			num_stripes = min_t(u64, map->sub_stripes *
					    (stripe_nr_end - stripe_nr_orig),
					    map->num_stripes);
C
Chris Mason 已提交
5148 5149
		else if (mirror_num)
			stripe_index += mirror_num - 1;
5150
		else {
J
Jan Schmidt 已提交
5151
			int old_stripe_index = stripe_index;
5152 5153
			stripe_index = find_live_mirror(fs_info, map,
					      stripe_index,
5154
					      map->sub_stripes, stripe_index +
5155 5156
					      current->pid % map->sub_stripes,
					      dev_replace_is_ongoing);
J
Jan Schmidt 已提交
5157
			mirror_num = stripe_index - old_stripe_index + 1;
5158
		}
D
David Woodhouse 已提交
5159 5160 5161 5162 5163 5164 5165 5166 5167 5168 5169 5170 5171 5172 5173 5174 5175 5176 5177

	} else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
				BTRFS_BLOCK_GROUP_RAID6)) {
		u64 tmp;

		if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
		    && raid_map_ret) {
			int i, rot;

			/* push stripe_nr back to the start of the full stripe */
			stripe_nr = raid56_full_stripe_start;
			do_div(stripe_nr, stripe_len);

			stripe_index = do_div(stripe_nr, nr_data_stripes(map));

			/* RAID[56] write or recovery. Return all stripes */
			num_stripes = map->num_stripes;
			max_errors = nr_parity_stripes(map);

5178
			raid_map = kmalloc_array(num_stripes, sizeof(u64),
D
David Woodhouse 已提交
5179 5180 5181 5182 5183 5184 5185 5186 5187 5188 5189 5190 5191 5192 5193 5194 5195 5196 5197 5198 5199 5200 5201 5202 5203 5204 5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216
					   GFP_NOFS);
			if (!raid_map) {
				ret = -ENOMEM;
				goto out;
			}

			/* Work out the disk rotation on this stripe-set */
			tmp = stripe_nr;
			rot = do_div(tmp, num_stripes);

			/* Fill in the logical address of each stripe */
			tmp = stripe_nr * nr_data_stripes(map);
			for (i = 0; i < nr_data_stripes(map); i++)
				raid_map[(i+rot) % num_stripes] =
					em->start + (tmp + i) * map->stripe_len;

			raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
			if (map->type & BTRFS_BLOCK_GROUP_RAID6)
				raid_map[(i+rot+1) % num_stripes] =
					RAID6_Q_STRIPE;

			*length = map->stripe_len;
			stripe_index = 0;
			stripe_offset = 0;
		} else {
			/*
			 * Mirror #0 or #1 means the original data block.
			 * Mirror #2 is RAID5 parity block.
			 * Mirror #3 is RAID6 Q block.
			 */
			stripe_index = do_div(stripe_nr, nr_data_stripes(map));
			if (mirror_num > 1)
				stripe_index = nr_data_stripes(map) +
						mirror_num - 2;

			/* We distribute the parity blocks across stripes */
			tmp = stripe_nr + stripe_index;
			stripe_index = do_div(tmp, map->num_stripes);
5217 5218 5219
			if (!(rw & (REQ_WRITE | REQ_DISCARD |
				    REQ_GET_READ_MIRRORS)) && mirror_num <= 1)
				mirror_num = 1;
D
David Woodhouse 已提交
5220
		}
5221 5222 5223 5224 5225 5226 5227
	} else {
		/*
		 * after this do_div call, stripe_nr is the number of stripes
		 * on this device we have to walk to find the data, and
		 * stripe_index is the number of our device in the stripe array
		 */
		stripe_index = do_div(stripe_nr, map->num_stripes);
5228
		mirror_num = stripe_index + 1;
5229
	}
5230
	BUG_ON(stripe_index >= map->num_stripes);
5231

5232
	num_alloc_stripes = num_stripes;
5233 5234 5235 5236 5237 5238
	if (dev_replace_is_ongoing) {
		if (rw & (REQ_WRITE | REQ_DISCARD))
			num_alloc_stripes <<= 1;
		if (rw & REQ_GET_READ_MIRRORS)
			num_alloc_stripes++;
	}
5239
	bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
L
Li Zefan 已提交
5240
	if (!bbio) {
5241
		kfree(raid_map);
L
Li Zefan 已提交
5242 5243 5244 5245 5246
		ret = -ENOMEM;
		goto out;
	}
	atomic_set(&bbio->error, 0);

5247
	if (rw & REQ_DISCARD) {
5248 5249 5250 5251
		int factor = 0;
		int sub_stripes = 0;
		u64 stripes_per_dev = 0;
		u32 remaining_stripes = 0;
L
Liu Bo 已提交
5252
		u32 last_stripe = 0;
5253 5254 5255 5256 5257 5258 5259 5260 5261 5262 5263 5264 5265

		if (map->type &
		    (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
			if (map->type & BTRFS_BLOCK_GROUP_RAID0)
				sub_stripes = 1;
			else
				sub_stripes = map->sub_stripes;

			factor = map->num_stripes / sub_stripes;
			stripes_per_dev = div_u64_rem(stripe_nr_end -
						      stripe_nr_orig,
						      factor,
						      &remaining_stripes);
L
Liu Bo 已提交
5266 5267
			div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
			last_stripe *= sub_stripes;
5268 5269
		}

5270
		for (i = 0; i < num_stripes; i++) {
5271
			bbio->stripes[i].physical =
5272 5273
				map->stripes[stripe_index].physical +
				stripe_offset + stripe_nr * map->stripe_len;
5274
			bbio->stripes[i].dev = map->stripes[stripe_index].dev;
5275

5276 5277 5278 5279
			if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
					 BTRFS_BLOCK_GROUP_RAID10)) {
				bbio->stripes[i].length = stripes_per_dev *
							  map->stripe_len;
L
Liu Bo 已提交
5280

5281 5282 5283
				if (i / sub_stripes < remaining_stripes)
					bbio->stripes[i].length +=
						map->stripe_len;
L
Liu Bo 已提交
5284 5285 5286 5287 5288 5289 5290 5291 5292

				/*
				 * Special for the first stripe and
				 * the last stripe:
				 *
				 * |-------|...|-------|
				 *     |----------|
				 *    off     end_off
				 */
5293
				if (i < sub_stripes)
5294
					bbio->stripes[i].length -=
5295
						stripe_offset;
L
Liu Bo 已提交
5296 5297 5298 5299

				if (stripe_index >= last_stripe &&
				    stripe_index <= (last_stripe +
						     sub_stripes - 1))
5300
					bbio->stripes[i].length -=
5301
						stripe_end_offset;
L
Liu Bo 已提交
5302

5303 5304
				if (i == sub_stripes - 1)
					stripe_offset = 0;
5305
			} else
5306
				bbio->stripes[i].length = *length;
5307 5308 5309 5310 5311 5312 5313 5314 5315 5316

			stripe_index++;
			if (stripe_index == map->num_stripes) {
				/* This could only happen for RAID0/10 */
				stripe_index = 0;
				stripe_nr++;
			}
		}
	} else {
		for (i = 0; i < num_stripes; i++) {
5317
			bbio->stripes[i].physical =
5318 5319 5320
				map->stripes[stripe_index].physical +
				stripe_offset +
				stripe_nr * map->stripe_len;
5321
			bbio->stripes[i].dev =
5322
				map->stripes[stripe_index].dev;
5323
			stripe_index++;
5324
		}
5325
	}
L
Li Zefan 已提交
5326

5327 5328
	if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
		max_errors = btrfs_chunk_max_errors(map);
L
Li Zefan 已提交
5329

5330 5331 5332 5333 5334 5335 5336 5337 5338 5339 5340 5341 5342 5343 5344 5345 5346 5347 5348 5349 5350 5351 5352 5353 5354 5355 5356 5357 5358 5359 5360 5361 5362
	if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
	    dev_replace->tgtdev != NULL) {
		int index_where_to_add;
		u64 srcdev_devid = dev_replace->srcdev->devid;

		/*
		 * duplicate the write operations while the dev replace
		 * procedure is running. Since the copying of the old disk
		 * to the new disk takes place at run time while the
		 * filesystem is mounted writable, the regular write
		 * operations to the old disk have to be duplicated to go
		 * to the new disk as well.
		 * Note that device->missing is handled by the caller, and
		 * that the write to the old disk is already set up in the
		 * stripes array.
		 */
		index_where_to_add = num_stripes;
		for (i = 0; i < num_stripes; i++) {
			if (bbio->stripes[i].dev->devid == srcdev_devid) {
				/* write to new disk, too */
				struct btrfs_bio_stripe *new =
					bbio->stripes + index_where_to_add;
				struct btrfs_bio_stripe *old =
					bbio->stripes + i;

				new->physical = old->physical;
				new->length = old->length;
				new->dev = dev_replace->tgtdev;
				index_where_to_add++;
				max_errors++;
			}
		}
		num_stripes = index_where_to_add;
5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375 5376 5377 5378 5379 5380 5381 5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399 5400 5401 5402 5403 5404 5405 5406 5407 5408
	} else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
		   dev_replace->tgtdev != NULL) {
		u64 srcdev_devid = dev_replace->srcdev->devid;
		int index_srcdev = 0;
		int found = 0;
		u64 physical_of_found = 0;

		/*
		 * During the dev-replace procedure, the target drive can
		 * also be used to read data in case it is needed to repair
		 * a corrupt block elsewhere. This is possible if the
		 * requested area is left of the left cursor. In this area,
		 * the target drive is a full copy of the source drive.
		 */
		for (i = 0; i < num_stripes; i++) {
			if (bbio->stripes[i].dev->devid == srcdev_devid) {
				/*
				 * In case of DUP, in order to keep it
				 * simple, only add the mirror with the
				 * lowest physical address
				 */
				if (found &&
				    physical_of_found <=
				     bbio->stripes[i].physical)
					continue;
				index_srcdev = i;
				found = 1;
				physical_of_found = bbio->stripes[i].physical;
			}
		}
		if (found) {
			u64 length = map->stripe_len;

			if (physical_of_found + length <=
			    dev_replace->cursor_left) {
				struct btrfs_bio_stripe *tgtdev_stripe =
					bbio->stripes + num_stripes;

				tgtdev_stripe->physical = physical_of_found;
				tgtdev_stripe->length =
					bbio->stripes[index_srcdev].length;
				tgtdev_stripe->dev = dev_replace->tgtdev;

				num_stripes++;
			}
		}
5409 5410
	}

L
Li Zefan 已提交
5411 5412 5413 5414
	*bbio_ret = bbio;
	bbio->num_stripes = num_stripes;
	bbio->max_errors = max_errors;
	bbio->mirror_num = mirror_num;
5415 5416 5417 5418 5419 5420 5421 5422 5423 5424 5425 5426

	/*
	 * this is the case that REQ_READ && dev_replace_is_ongoing &&
	 * mirror_num == num_stripes + 1 && dev_replace target drive is
	 * available as a mirror
	 */
	if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
		WARN_ON(num_stripes > 1);
		bbio->stripes[0].dev = dev_replace->tgtdev;
		bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
		bbio->mirror_num = map->num_stripes + 1;
	}
D
David Woodhouse 已提交
5427 5428 5429 5430
	if (raid_map) {
		sort_parity_stripes(bbio, raid_map);
		*raid_map_ret = raid_map;
	}
5431
out:
5432 5433
	if (dev_replace_is_ongoing)
		btrfs_dev_replace_unlock(dev_replace);
5434
	free_extent_map(em);
L
Li Zefan 已提交
5435
	return ret;
5436 5437
}

5438
int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
5439
		      u64 logical, u64 *length,
5440
		      struct btrfs_bio **bbio_ret, int mirror_num)
5441
{
5442
	return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
D
David Woodhouse 已提交
5443
				 mirror_num, NULL);
5444 5445
}

Y
Yan Zheng 已提交
5446 5447 5448 5449 5450 5451 5452 5453 5454 5455 5456
int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
		     u64 chunk_start, u64 physical, u64 devid,
		     u64 **logical, int *naddrs, int *stripe_len)
{
	struct extent_map_tree *em_tree = &map_tree->map_tree;
	struct extent_map *em;
	struct map_lookup *map;
	u64 *buf;
	u64 bytenr;
	u64 length;
	u64 stripe_nr;
D
David Woodhouse 已提交
5457
	u64 rmap_len;
Y
Yan Zheng 已提交
5458 5459
	int i, j, nr = 0;

5460
	read_lock(&em_tree->lock);
Y
Yan Zheng 已提交
5461
	em = lookup_extent_mapping(em_tree, chunk_start, 1);
5462
	read_unlock(&em_tree->lock);
Y
Yan Zheng 已提交
5463

5464
	if (!em) {
5465
		printk(KERN_ERR "BTRFS: couldn't find em for chunk %Lu\n",
5466 5467 5468 5469 5470
		       chunk_start);
		return -EIO;
	}

	if (em->start != chunk_start) {
5471
		printk(KERN_ERR "BTRFS: bad chunk start, em=%Lu, wanted=%Lu\n",
5472 5473 5474 5475
		       em->start, chunk_start);
		free_extent_map(em);
		return -EIO;
	}
Y
Yan Zheng 已提交
5476 5477 5478
	map = (struct map_lookup *)em->bdev;

	length = em->len;
D
David Woodhouse 已提交
5479 5480
	rmap_len = map->stripe_len;

Y
Yan Zheng 已提交
5481 5482 5483 5484
	if (map->type & BTRFS_BLOCK_GROUP_RAID10)
		do_div(length, map->num_stripes / map->sub_stripes);
	else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
		do_div(length, map->num_stripes);
D
David Woodhouse 已提交
5485 5486 5487 5488 5489
	else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
			      BTRFS_BLOCK_GROUP_RAID6)) {
		do_div(length, nr_data_stripes(map));
		rmap_len = map->stripe_len * nr_data_stripes(map);
	}
Y
Yan Zheng 已提交
5490 5491

	buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
5492
	BUG_ON(!buf); /* -ENOMEM */
Y
Yan Zheng 已提交
5493 5494 5495 5496 5497 5498 5499 5500 5501 5502 5503 5504 5505 5506 5507 5508

	for (i = 0; i < map->num_stripes; i++) {
		if (devid && map->stripes[i].dev->devid != devid)
			continue;
		if (map->stripes[i].physical > physical ||
		    map->stripes[i].physical + length <= physical)
			continue;

		stripe_nr = physical - map->stripes[i].physical;
		do_div(stripe_nr, map->stripe_len);

		if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
			stripe_nr = stripe_nr * map->num_stripes + i;
			do_div(stripe_nr, map->sub_stripes);
		} else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
			stripe_nr = stripe_nr * map->num_stripes + i;
D
David Woodhouse 已提交
5509 5510 5511 5512 5513
		} /* else if RAID[56], multiply by nr_data_stripes().
		   * Alternatively, just use rmap_len below instead of
		   * map->stripe_len */

		bytenr = chunk_start + stripe_nr * rmap_len;
5514
		WARN_ON(nr >= map->num_stripes);
Y
Yan Zheng 已提交
5515 5516 5517 5518
		for (j = 0; j < nr; j++) {
			if (buf[j] == bytenr)
				break;
		}
5519 5520
		if (j == nr) {
			WARN_ON(nr >= map->num_stripes);
Y
Yan Zheng 已提交
5521
			buf[nr++] = bytenr;
5522
		}
Y
Yan Zheng 已提交
5523 5524 5525 5526
	}

	*logical = buf;
	*naddrs = nr;
D
David Woodhouse 已提交
5527
	*stripe_len = rmap_len;
Y
Yan Zheng 已提交
5528 5529 5530

	free_extent_map(em);
	return 0;
5531 5532
}

5533 5534 5535 5536 5537 5538 5539 5540 5541
static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio, int err)
{
	if (likely(bbio->flags & BTRFS_BIO_ORIG_BIO_SUBMITTED))
		bio_endio_nodec(bio, err);
	else
		bio_endio(bio, err);
	kfree(bbio);
}

5542
static void btrfs_end_bio(struct bio *bio, int err)
5543
{
5544
	struct btrfs_bio *bbio = bio->bi_private;
5545
	struct btrfs_device *dev = bbio->stripes[0].dev;
5546
	int is_orig_bio = 0;
5547

5548
	if (err) {
5549
		atomic_inc(&bbio->error);
5550 5551
		if (err == -EIO || err == -EREMOTEIO) {
			unsigned int stripe_index =
5552
				btrfs_io_bio(bio)->stripe_index;
5553 5554 5555

			BUG_ON(stripe_index >= bbio->num_stripes);
			dev = bbio->stripes[stripe_index].dev;
5556 5557 5558 5559 5560 5561 5562 5563 5564 5565 5566 5567
			if (dev->bdev) {
				if (bio->bi_rw & WRITE)
					btrfs_dev_stat_inc(dev,
						BTRFS_DEV_STAT_WRITE_ERRS);
				else
					btrfs_dev_stat_inc(dev,
						BTRFS_DEV_STAT_READ_ERRS);
				if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
					btrfs_dev_stat_inc(dev,
						BTRFS_DEV_STAT_FLUSH_ERRS);
				btrfs_dev_stat_print_on_error(dev);
			}
5568 5569
		}
	}
5570

5571
	if (bio == bbio->orig_bio)
5572 5573
		is_orig_bio = 1;

5574 5575
	btrfs_bio_counter_dec(bbio->fs_info);

5576
	if (atomic_dec_and_test(&bbio->stripes_pending)) {
5577 5578
		if (!is_orig_bio) {
			bio_put(bio);
5579
			bio = bbio->orig_bio;
5580
		}
5581

5582 5583
		bio->bi_private = bbio->private;
		bio->bi_end_io = bbio->end_io;
5584
		btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5585
		/* only send an error to the higher layers if it is
D
David Woodhouse 已提交
5586
		 * beyond the tolerance of the btrfs bio
5587
		 */
5588
		if (atomic_read(&bbio->error) > bbio->max_errors) {
5589
			err = -EIO;
5590
		} else {
5591 5592 5593 5594 5595
			/*
			 * this bio is actually up to date, we didn't
			 * go over the max number of errors
			 */
			set_bit(BIO_UPTODATE, &bio->bi_flags);
5596
			err = 0;
5597
		}
5598

5599
		btrfs_end_bbio(bbio, bio, err);
5600
	} else if (!is_orig_bio) {
5601 5602 5603 5604
		bio_put(bio);
	}
}

5605 5606 5607 5608 5609 5610 5611
/*
 * see run_scheduled_bios for a description of why bios are collected for
 * async submit.
 *
 * This will add one bio to the pending list for a device and make sure
 * the work struct is scheduled.
 */
5612 5613 5614
static noinline void btrfs_schedule_bio(struct btrfs_root *root,
					struct btrfs_device *device,
					int rw, struct bio *bio)
5615 5616
{
	int should_queue = 1;
5617
	struct btrfs_pending_bios *pending_bios;
5618

D
David Woodhouse 已提交
5619 5620 5621 5622 5623
	if (device->missing || !device->bdev) {
		bio_endio(bio, -EIO);
		return;
	}

5624
	/* don't bother with additional async steps for reads, right now */
5625
	if (!(rw & REQ_WRITE)) {
5626
		bio_get(bio);
5627
		btrfsic_submit_bio(rw, bio);
5628
		bio_put(bio);
5629
		return;
5630 5631 5632
	}

	/*
5633
	 * nr_async_bios allows us to reliably return congestion to the
5634 5635 5636 5637
	 * higher layers.  Otherwise, the async bio makes it appear we have
	 * made progress against dirty pages when we've really just put it
	 * on a queue for later
	 */
5638
	atomic_inc(&root->fs_info->nr_async_bios);
5639
	WARN_ON(bio->bi_next);
5640 5641 5642 5643
	bio->bi_next = NULL;
	bio->bi_rw |= rw;

	spin_lock(&device->io_lock);
5644
	if (bio->bi_rw & REQ_SYNC)
5645 5646 5647
		pending_bios = &device->pending_sync_bios;
	else
		pending_bios = &device->pending_bios;
5648

5649 5650
	if (pending_bios->tail)
		pending_bios->tail->bi_next = bio;
5651

5652 5653 5654
	pending_bios->tail = bio;
	if (!pending_bios->head)
		pending_bios->head = bio;
5655 5656 5657 5658 5659 5660
	if (device->running_pending)
		should_queue = 0;

	spin_unlock(&device->io_lock);

	if (should_queue)
5661 5662
		btrfs_queue_work(root->fs_info->submit_workers,
				 &device->work);
5663 5664
}

5665 5666 5667 5668 5669
static int bio_size_ok(struct block_device *bdev, struct bio *bio,
		       sector_t sector)
{
	struct bio_vec *prev;
	struct request_queue *q = bdev_get_queue(bdev);
5670
	unsigned int max_sectors = queue_max_sectors(q);
5671 5672 5673 5674 5675 5676
	struct bvec_merge_data bvm = {
		.bi_bdev = bdev,
		.bi_sector = sector,
		.bi_rw = bio->bi_rw,
	};

5677
	if (WARN_ON(bio->bi_vcnt == 0))
5678 5679 5680
		return 1;

	prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5681
	if (bio_sectors(bio) > max_sectors)
5682 5683 5684 5685 5686
		return 0;

	if (!q->merge_bvec_fn)
		return 1;

5687
	bvm.bi_size = bio->bi_iter.bi_size - prev->bv_len;
5688 5689 5690 5691 5692 5693 5694 5695 5696 5697 5698 5699
	if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
		return 0;
	return 1;
}

static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
			      struct bio *bio, u64 physical, int dev_nr,
			      int rw, int async)
{
	struct btrfs_device *dev = bbio->stripes[dev_nr].dev;

	bio->bi_private = bbio;
5700
	btrfs_io_bio(bio)->stripe_index = dev_nr;
5701
	bio->bi_end_io = btrfs_end_bio;
5702
	bio->bi_iter.bi_sector = physical >> 9;
5703 5704 5705 5706 5707 5708
#ifdef DEBUG
	{
		struct rcu_string *name;

		rcu_read_lock();
		name = rcu_dereference(dev->name);
M
Masanari Iida 已提交
5709
		pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5710
			 "(%s id %llu), size=%u\n", rw,
5711 5712
			 (u64)bio->bi_iter.bi_sector, (u_long)dev->bdev->bd_dev,
			 name->str, dev->devid, bio->bi_iter.bi_size);
5713 5714 5715 5716
		rcu_read_unlock();
	}
#endif
	bio->bi_bdev = dev->bdev;
5717 5718 5719

	btrfs_bio_counter_inc_noblocked(root->fs_info);

5720
	if (async)
D
David Woodhouse 已提交
5721
		btrfs_schedule_bio(root, dev, rw, bio);
5722 5723 5724 5725 5726 5727 5728 5729 5730 5731 5732 5733 5734 5735 5736 5737 5738 5739 5740 5741 5742
	else
		btrfsic_submit_bio(rw, bio);
}

static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
			      struct bio *first_bio, struct btrfs_device *dev,
			      int dev_nr, int rw, int async)
{
	struct bio_vec *bvec = first_bio->bi_io_vec;
	struct bio *bio;
	int nr_vecs = bio_get_nr_vecs(dev->bdev);
	u64 physical = bbio->stripes[dev_nr].physical;

again:
	bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
	if (!bio)
		return -ENOMEM;

	while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
		if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
				 bvec->bv_offset) < bvec->bv_len) {
5743
			u64 len = bio->bi_iter.bi_size;
5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760 5761

			atomic_inc(&bbio->stripes_pending);
			submit_stripe_bio(root, bbio, bio, physical, dev_nr,
					  rw, async);
			physical += len;
			goto again;
		}
		bvec++;
	}

	submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
	return 0;
}

static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
{
	atomic_inc(&bbio->error);
	if (atomic_dec_and_test(&bbio->stripes_pending)) {
5762 5763 5764
		/* Shoud be the original bio. */
		WARN_ON(bio != bbio->orig_bio);

5765 5766
		bio->bi_private = bbio->private;
		bio->bi_end_io = bbio->end_io;
5767
		btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5768
		bio->bi_iter.bi_sector = logical >> 9;
5769 5770

		btrfs_end_bbio(bbio, bio, -EIO);
5771 5772 5773
	}
}

5774
int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5775
		  int mirror_num, int async_submit)
5776 5777
{
	struct btrfs_device *dev;
5778
	struct bio *first_bio = bio;
5779
	u64 logical = (u64)bio->bi_iter.bi_sector << 9;
5780 5781
	u64 length = 0;
	u64 map_length;
D
David Woodhouse 已提交
5782
	u64 *raid_map = NULL;
5783
	int ret;
5784 5785
	int dev_nr = 0;
	int total_devs = 1;
5786
	struct btrfs_bio *bbio = NULL;
5787

5788
	length = bio->bi_iter.bi_size;
5789
	map_length = length;
5790

5791
	btrfs_bio_counter_inc_blocked(root->fs_info);
D
David Woodhouse 已提交
5792 5793
	ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
			      mirror_num, &raid_map);
5794 5795
	if (ret) {
		btrfs_bio_counter_dec(root->fs_info);
5796
		return ret;
5797
	}
5798

5799
	total_devs = bbio->num_stripes;
D
David Woodhouse 已提交
5800 5801 5802
	bbio->orig_bio = first_bio;
	bbio->private = first_bio->bi_private;
	bbio->end_io = first_bio->bi_end_io;
5803
	bbio->fs_info = root->fs_info;
D
David Woodhouse 已提交
5804 5805 5806 5807 5808 5809
	atomic_set(&bbio->stripes_pending, bbio->num_stripes);

	if (raid_map) {
		/* In this case, map_length has been set to the length of
		   a single stripe; not the whole write */
		if (rw & WRITE) {
5810 5811
			ret = raid56_parity_write(root, bio, bbio,
						  raid_map, map_length);
D
David Woodhouse 已提交
5812
		} else {
5813 5814 5815
			ret = raid56_parity_recover(root, bio, bbio,
						    raid_map, map_length,
						    mirror_num);
D
David Woodhouse 已提交
5816
		}
5817 5818 5819 5820 5821 5822
		/*
		 * FIXME, replace dosen't support raid56 yet, please fix
		 * it in the future.
		 */
		btrfs_bio_counter_dec(root->fs_info);
		return ret;
D
David Woodhouse 已提交
5823 5824
	}

5825
	if (map_length < length) {
5826
		btrfs_crit(root->fs_info, "mapping failed logical %llu bio len %llu len %llu",
5827
			logical, length, map_length);
5828 5829
		BUG();
	}
5830

C
Chris Mason 已提交
5831
	while (dev_nr < total_devs) {
5832 5833 5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845 5846 5847 5848 5849 5850 5851
		dev = bbio->stripes[dev_nr].dev;
		if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
			bbio_error(bbio, first_bio, logical);
			dev_nr++;
			continue;
		}

		/*
		 * Check and see if we're ok with this bio based on it's size
		 * and offset with the given device.
		 */
		if (!bio_size_ok(dev->bdev, first_bio,
				 bbio->stripes[dev_nr].physical >> 9)) {
			ret = breakup_stripe_bio(root, bbio, first_bio, dev,
						 dev_nr, rw, async_submit);
			BUG_ON(ret);
			dev_nr++;
			continue;
		}

5852
		if (dev_nr < total_devs - 1) {
5853
			bio = btrfs_bio_clone(first_bio, GFP_NOFS);
5854
			BUG_ON(!bio); /* -ENOMEM */
5855 5856
		} else {
			bio = first_bio;
5857
			bbio->flags |= BTRFS_BIO_ORIG_BIO_SUBMITTED;
5858
		}
5859 5860 5861 5862

		submit_stripe_bio(root, bbio, bio,
				  bbio->stripes[dev_nr].physical, dev_nr, rw,
				  async_submit);
5863 5864
		dev_nr++;
	}
5865
	btrfs_bio_counter_dec(root->fs_info);
5866 5867 5868
	return 0;
}

5869
struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
Y
Yan Zheng 已提交
5870
				       u8 *uuid, u8 *fsid)
5871
{
Y
Yan Zheng 已提交
5872 5873 5874
	struct btrfs_device *device;
	struct btrfs_fs_devices *cur_devices;

5875
	cur_devices = fs_info->fs_devices;
Y
Yan Zheng 已提交
5876 5877 5878 5879 5880 5881 5882 5883 5884 5885 5886
	while (cur_devices) {
		if (!fsid ||
		    !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
			device = __find_device(&cur_devices->devices,
					       devid, uuid);
			if (device)
				return device;
		}
		cur_devices = cur_devices->seed;
	}
	return NULL;
5887 5888
}

5889
static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5890
					    struct btrfs_fs_devices *fs_devices,
5891 5892 5893 5894
					    u64 devid, u8 *dev_uuid)
{
	struct btrfs_device *device;

5895 5896
	device = btrfs_alloc_device(NULL, &devid, dev_uuid);
	if (IS_ERR(device))
5897
		return NULL;
5898 5899

	list_add(&device->dev_list, &fs_devices->devices);
Y
Yan Zheng 已提交
5900
	device->fs_devices = fs_devices;
5901
	fs_devices->num_devices++;
5902 5903

	device->missing = 1;
5904
	fs_devices->missing_devices++;
5905

5906 5907 5908
	return device;
}

5909 5910 5911 5912 5913 5914 5915 5916 5917 5918 5919 5920 5921 5922 5923 5924 5925 5926 5927 5928
/**
 * btrfs_alloc_device - allocate struct btrfs_device
 * @fs_info:	used only for generating a new devid, can be NULL if
 *		devid is provided (i.e. @devid != NULL).
 * @devid:	a pointer to devid for this device.  If NULL a new devid
 *		is generated.
 * @uuid:	a pointer to UUID for this device.  If NULL a new UUID
 *		is generated.
 *
 * Return: a pointer to a new &struct btrfs_device on success; ERR_PTR()
 * on error.  Returned struct is not linked onto any lists and can be
 * destroyed with kfree() right away.
 */
struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
					const u64 *devid,
					const u8 *uuid)
{
	struct btrfs_device *dev;
	u64 tmp;

5929
	if (WARN_ON(!devid && !fs_info))
5930 5931 5932 5933 5934 5935 5936 5937 5938 5939 5940 5941 5942 5943 5944 5945 5946 5947 5948 5949 5950 5951 5952 5953
		return ERR_PTR(-EINVAL);

	dev = __alloc_device();
	if (IS_ERR(dev))
		return dev;

	if (devid)
		tmp = *devid;
	else {
		int ret;

		ret = find_next_devid(fs_info, &tmp);
		if (ret) {
			kfree(dev);
			return ERR_PTR(ret);
		}
	}
	dev->devid = tmp;

	if (uuid)
		memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE);
	else
		generate_random_uuid(dev->uuid);

5954 5955
	btrfs_init_work(&dev->work, btrfs_submit_helper,
			pending_bios_fn, NULL, NULL);
5956 5957 5958 5959

	return dev;
}

5960 5961 5962 5963 5964 5965 5966 5967 5968 5969
static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
			  struct extent_buffer *leaf,
			  struct btrfs_chunk *chunk)
{
	struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
	struct map_lookup *map;
	struct extent_map *em;
	u64 logical;
	u64 length;
	u64 devid;
5970
	u8 uuid[BTRFS_UUID_SIZE];
5971
	int num_stripes;
5972
	int ret;
5973
	int i;
5974

5975 5976
	logical = key->offset;
	length = btrfs_chunk_length(leaf, chunk);
5977

5978
	read_lock(&map_tree->map_tree.lock);
5979
	em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5980
	read_unlock(&map_tree->map_tree.lock);
5981 5982 5983 5984 5985 5986 5987 5988 5989

	/* already mapped? */
	if (em && em->start <= logical && em->start + em->len > logical) {
		free_extent_map(em);
		return 0;
	} else if (em) {
		free_extent_map(em);
	}

5990
	em = alloc_extent_map();
5991 5992
	if (!em)
		return -ENOMEM;
5993 5994
	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5995 5996 5997 5998 5999
	if (!map) {
		free_extent_map(em);
		return -ENOMEM;
	}

6000
	set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
6001 6002 6003
	em->bdev = (struct block_device *)map;
	em->start = logical;
	em->len = length;
6004
	em->orig_start = 0;
6005
	em->block_start = 0;
C
Chris Mason 已提交
6006
	em->block_len = em->len;
6007

6008 6009 6010 6011 6012 6013
	map->num_stripes = num_stripes;
	map->io_width = btrfs_chunk_io_width(leaf, chunk);
	map->io_align = btrfs_chunk_io_align(leaf, chunk);
	map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
	map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
	map->type = btrfs_chunk_type(leaf, chunk);
C
Chris Mason 已提交
6014
	map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
6015 6016 6017 6018
	for (i = 0; i < num_stripes; i++) {
		map->stripes[i].physical =
			btrfs_stripe_offset_nr(leaf, chunk, i);
		devid = btrfs_stripe_devid_nr(leaf, chunk, i);
6019 6020 6021
		read_extent_buffer(leaf, uuid, (unsigned long)
				   btrfs_stripe_dev_uuid_nr(chunk, i),
				   BTRFS_UUID_SIZE);
6022 6023
		map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
							uuid, NULL);
6024
		if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
6025 6026 6027
			free_extent_map(em);
			return -EIO;
		}
6028 6029
		if (!map->stripes[i].dev) {
			map->stripes[i].dev =
6030 6031
				add_missing_dev(root, root->fs_info->fs_devices,
						devid, uuid);
6032 6033 6034 6035 6036 6037
			if (!map->stripes[i].dev) {
				free_extent_map(em);
				return -EIO;
			}
		}
		map->stripes[i].dev->in_fs_metadata = 1;
6038 6039
	}

6040
	write_lock(&map_tree->map_tree.lock);
J
Josef Bacik 已提交
6041
	ret = add_extent_mapping(&map_tree->map_tree, em, 0);
6042
	write_unlock(&map_tree->map_tree.lock);
6043
	BUG_ON(ret); /* Tree corruption */
6044 6045 6046 6047 6048
	free_extent_map(em);

	return 0;
}

6049
static void fill_device_from_item(struct extent_buffer *leaf,
6050 6051 6052 6053 6054 6055
				 struct btrfs_dev_item *dev_item,
				 struct btrfs_device *device)
{
	unsigned long ptr;

	device->devid = btrfs_device_id(leaf, dev_item);
6056 6057
	device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
	device->total_bytes = device->disk_total_bytes;
6058
	device->commit_total_bytes = device->disk_total_bytes;
6059
	device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
6060
	device->commit_bytes_used = device->bytes_used;
6061 6062 6063 6064
	device->type = btrfs_device_type(leaf, dev_item);
	device->io_align = btrfs_device_io_align(leaf, dev_item);
	device->io_width = btrfs_device_io_width(leaf, dev_item);
	device->sector_size = btrfs_device_sector_size(leaf, dev_item);
6065
	WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
6066
	device->is_tgtdev_for_dev_replace = 0;
6067

6068
	ptr = btrfs_device_uuid(dev_item);
6069
	read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
6070 6071
}

6072 6073
static struct btrfs_fs_devices *open_seed_devices(struct btrfs_root *root,
						  u8 *fsid)
Y
Yan Zheng 已提交
6074 6075 6076 6077
{
	struct btrfs_fs_devices *fs_devices;
	int ret;

6078
	BUG_ON(!mutex_is_locked(&uuid_mutex));
Y
Yan Zheng 已提交
6079 6080 6081

	fs_devices = root->fs_info->fs_devices->seed;
	while (fs_devices) {
6082 6083 6084
		if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE))
			return fs_devices;

Y
Yan Zheng 已提交
6085 6086 6087 6088 6089
		fs_devices = fs_devices->seed;
	}

	fs_devices = find_fsid(fsid);
	if (!fs_devices) {
6090 6091 6092 6093 6094 6095 6096 6097 6098 6099
		if (!btrfs_test_opt(root, DEGRADED))
			return ERR_PTR(-ENOENT);

		fs_devices = alloc_fs_devices(fsid);
		if (IS_ERR(fs_devices))
			return fs_devices;

		fs_devices->seeding = 1;
		fs_devices->opened = 1;
		return fs_devices;
Y
Yan Zheng 已提交
6100
	}
Y
Yan Zheng 已提交
6101 6102

	fs_devices = clone_fs_devices(fs_devices);
6103 6104
	if (IS_ERR(fs_devices))
		return fs_devices;
Y
Yan Zheng 已提交
6105

6106
	ret = __btrfs_open_devices(fs_devices, FMODE_READ,
6107
				   root->fs_info->bdev_holder);
6108 6109
	if (ret) {
		free_fs_devices(fs_devices);
6110
		fs_devices = ERR_PTR(ret);
Y
Yan Zheng 已提交
6111
		goto out;
6112
	}
Y
Yan Zheng 已提交
6113 6114 6115

	if (!fs_devices->seeding) {
		__btrfs_close_devices(fs_devices);
Y
Yan Zheng 已提交
6116
		free_fs_devices(fs_devices);
6117
		fs_devices = ERR_PTR(-EINVAL);
Y
Yan Zheng 已提交
6118 6119 6120 6121 6122 6123
		goto out;
	}

	fs_devices->seed = root->fs_info->fs_devices->seed;
	root->fs_info->fs_devices->seed = fs_devices;
out:
6124
	return fs_devices;
Y
Yan Zheng 已提交
6125 6126
}

6127
static int read_one_dev(struct btrfs_root *root,
6128 6129 6130
			struct extent_buffer *leaf,
			struct btrfs_dev_item *dev_item)
{
6131
	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
6132 6133 6134
	struct btrfs_device *device;
	u64 devid;
	int ret;
Y
Yan Zheng 已提交
6135
	u8 fs_uuid[BTRFS_UUID_SIZE];
6136 6137
	u8 dev_uuid[BTRFS_UUID_SIZE];

6138
	devid = btrfs_device_id(leaf, dev_item);
6139
	read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
6140
			   BTRFS_UUID_SIZE);
6141
	read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
Y
Yan Zheng 已提交
6142 6143 6144
			   BTRFS_UUID_SIZE);

	if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
6145 6146 6147
		fs_devices = open_seed_devices(root, fs_uuid);
		if (IS_ERR(fs_devices))
			return PTR_ERR(fs_devices);
Y
Yan Zheng 已提交
6148 6149
	}

6150
	device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
6151
	if (!device) {
Y
Yan Zheng 已提交
6152
		if (!btrfs_test_opt(root, DEGRADED))
Y
Yan Zheng 已提交
6153 6154
			return -EIO;

6155 6156 6157 6158 6159 6160 6161 6162 6163
		btrfs_warn(root->fs_info, "devid %llu missing", devid);
		device = add_missing_dev(root, fs_devices, devid, dev_uuid);
		if (!device)
			return -ENOMEM;
	} else {
		if (!device->bdev && !btrfs_test_opt(root, DEGRADED))
			return -EIO;

		if(!device->bdev && !device->missing) {
6164 6165 6166 6167 6168 6169
			/*
			 * this happens when a device that was properly setup
			 * in the device info lists suddenly goes bad.
			 * device->bdev is NULL, and so we have to set
			 * device->missing to one here
			 */
6170
			device->fs_devices->missing_devices++;
6171
			device->missing = 1;
Y
Yan Zheng 已提交
6172
		}
6173 6174 6175 6176 6177 6178 6179 6180 6181 6182 6183 6184 6185 6186

		/* Move the device to its own fs_devices */
		if (device->fs_devices != fs_devices) {
			ASSERT(device->missing);

			list_move(&device->dev_list, &fs_devices->devices);
			device->fs_devices->num_devices--;
			fs_devices->num_devices++;

			device->fs_devices->missing_devices--;
			fs_devices->missing_devices++;

			device->fs_devices = fs_devices;
		}
Y
Yan Zheng 已提交
6187 6188 6189 6190 6191 6192 6193
	}

	if (device->fs_devices != root->fs_info->fs_devices) {
		BUG_ON(device->writeable);
		if (device->generation !=
		    btrfs_device_generation(leaf, dev_item))
			return -EINVAL;
6194
	}
6195 6196

	fill_device_from_item(leaf, dev_item, device);
6197
	device->in_fs_metadata = 1;
6198
	if (device->writeable && !device->is_tgtdev_for_dev_replace) {
Y
Yan Zheng 已提交
6199
		device->fs_devices->total_rw_bytes += device->total_bytes;
6200 6201 6202 6203 6204
		spin_lock(&root->fs_info->free_chunk_lock);
		root->fs_info->free_chunk_space += device->total_bytes -
			device->bytes_used;
		spin_unlock(&root->fs_info->free_chunk_lock);
	}
6205 6206 6207 6208
	ret = 0;
	return ret;
}

Y
Yan Zheng 已提交
6209
int btrfs_read_sys_array(struct btrfs_root *root)
6210
{
6211
	struct btrfs_super_block *super_copy = root->fs_info->super_copy;
6212
	struct extent_buffer *sb;
6213 6214
	struct btrfs_disk_key *disk_key;
	struct btrfs_chunk *chunk;
6215 6216 6217
	u8 *ptr;
	unsigned long sb_ptr;
	int ret = 0;
6218 6219 6220 6221
	u32 num_stripes;
	u32 array_size;
	u32 len = 0;
	u32 cur;
6222
	struct btrfs_key key;
6223

Y
Yan Zheng 已提交
6224
	sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
6225 6226 6227 6228
					  BTRFS_SUPER_INFO_SIZE);
	if (!sb)
		return -ENOMEM;
	btrfs_set_buffer_uptodate(sb);
6229
	btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
6230 6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241 6242
	/*
	 * The sb extent buffer is artifical and just used to read the system array.
	 * btrfs_set_buffer_uptodate() call does not properly mark all it's
	 * pages up-to-date when the page is larger: extent does not cover the
	 * whole page and consequently check_page_uptodate does not find all
	 * the page's extents up-to-date (the hole beyond sb),
	 * write_extent_buffer then triggers a WARN_ON.
	 *
	 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
	 * but sb spans only this function. Add an explicit SetPageUptodate call
	 * to silence the warning eg. on PowerPC 64.
	 */
	if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
6243
		SetPageUptodate(sb->pages[0]);
6244

6245
	write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
6246 6247 6248 6249 6250 6251 6252 6253 6254 6255
	array_size = btrfs_super_sys_array_size(super_copy);

	ptr = super_copy->sys_chunk_array;
	sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
	cur = 0;

	while (cur < array_size) {
		disk_key = (struct btrfs_disk_key *)ptr;
		btrfs_disk_key_to_cpu(&key, disk_key);

6256
		len = sizeof(*disk_key); ptr += len;
6257 6258 6259
		sb_ptr += len;
		cur += len;

6260
		if (key.type == BTRFS_CHUNK_ITEM_KEY) {
6261
			chunk = (struct btrfs_chunk *)sb_ptr;
6262
			ret = read_one_chunk(root, &key, sb, chunk);
6263 6264
			if (ret)
				break;
6265 6266 6267
			num_stripes = btrfs_chunk_num_stripes(sb, chunk);
			len = btrfs_chunk_item_size(num_stripes);
		} else {
6268 6269
			ret = -EIO;
			break;
6270 6271 6272 6273 6274
		}
		ptr += len;
		sb_ptr += len;
		cur += len;
	}
6275
	free_extent_buffer(sb);
6276
	return ret;
6277 6278 6279 6280 6281 6282 6283 6284 6285 6286 6287 6288 6289 6290 6291 6292 6293
}

int btrfs_read_chunk_tree(struct btrfs_root *root)
{
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_key key;
	struct btrfs_key found_key;
	int ret;
	int slot;

	root = root->fs_info->chunk_root;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

6294 6295 6296
	mutex_lock(&uuid_mutex);
	lock_chunks(root);

6297 6298 6299 6300 6301
	/*
	 * Read all device items, and then all the chunk items. All
	 * device items are found before any chunk item (their object id
	 * is smaller than the lowest possible object id for a chunk
	 * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
6302 6303 6304 6305 6306
	 */
	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.offset = 0;
	key.type = 0;
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6307 6308
	if (ret < 0)
		goto error;
C
Chris Mason 已提交
6309
	while (1) {
6310 6311 6312 6313 6314 6315 6316 6317 6318 6319 6320
		leaf = path->nodes[0];
		slot = path->slots[0];
		if (slot >= btrfs_header_nritems(leaf)) {
			ret = btrfs_next_leaf(root, path);
			if (ret == 0)
				continue;
			if (ret < 0)
				goto error;
			break;
		}
		btrfs_item_key_to_cpu(leaf, &found_key, slot);
6321 6322 6323
		if (found_key.type == BTRFS_DEV_ITEM_KEY) {
			struct btrfs_dev_item *dev_item;
			dev_item = btrfs_item_ptr(leaf, slot,
6324
						  struct btrfs_dev_item);
6325 6326 6327
			ret = read_one_dev(root, leaf, dev_item);
			if (ret)
				goto error;
6328 6329 6330 6331
		} else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
			struct btrfs_chunk *chunk;
			chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
			ret = read_one_chunk(root, &found_key, leaf, chunk);
Y
Yan Zheng 已提交
6332 6333
			if (ret)
				goto error;
6334 6335 6336 6337 6338
		}
		path->slots[0]++;
	}
	ret = 0;
error:
6339 6340 6341
	unlock_chunks(root);
	mutex_unlock(&uuid_mutex);

Y
Yan Zheng 已提交
6342
	btrfs_free_path(path);
6343 6344
	return ret;
}
6345

6346 6347 6348 6349 6350
void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
{
	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
	struct btrfs_device *device;

6351 6352 6353 6354 6355 6356 6357 6358
	while (fs_devices) {
		mutex_lock(&fs_devices->device_list_mutex);
		list_for_each_entry(device, &fs_devices->devices, dev_list)
			device->dev_root = fs_info->dev_root;
		mutex_unlock(&fs_devices->device_list_mutex);

		fs_devices = fs_devices->seed;
	}
6359 6360
}

6361 6362 6363 6364 6365 6366 6367 6368 6369 6370 6371 6372 6373 6374 6375 6376 6377 6378 6379 6380 6381 6382 6383 6384 6385 6386 6387 6388 6389 6390 6391 6392 6393 6394 6395 6396 6397 6398 6399 6400 6401 6402 6403 6404 6405 6406 6407 6408 6409 6410 6411 6412 6413 6414 6415 6416 6417 6418 6419 6420 6421 6422 6423 6424 6425 6426 6427 6428 6429 6430 6431 6432 6433 6434 6435 6436 6437 6438 6439 6440 6441 6442 6443 6444 6445 6446 6447 6448
static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
{
	int i;

	for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
		btrfs_dev_stat_reset(dev, i);
}

int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
{
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_root *dev_root = fs_info->dev_root;
	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
	struct extent_buffer *eb;
	int slot;
	int ret = 0;
	struct btrfs_device *device;
	struct btrfs_path *path = NULL;
	int i;

	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	mutex_lock(&fs_devices->device_list_mutex);
	list_for_each_entry(device, &fs_devices->devices, dev_list) {
		int item_size;
		struct btrfs_dev_stats_item *ptr;

		key.objectid = 0;
		key.type = BTRFS_DEV_STATS_KEY;
		key.offset = device->devid;
		ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
		if (ret) {
			__btrfs_reset_dev_stats(device);
			device->dev_stats_valid = 1;
			btrfs_release_path(path);
			continue;
		}
		slot = path->slots[0];
		eb = path->nodes[0];
		btrfs_item_key_to_cpu(eb, &found_key, slot);
		item_size = btrfs_item_size_nr(eb, slot);

		ptr = btrfs_item_ptr(eb, slot,
				     struct btrfs_dev_stats_item);

		for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
			if (item_size >= (1 + i) * sizeof(__le64))
				btrfs_dev_stat_set(device, i,
					btrfs_dev_stats_value(eb, ptr, i));
			else
				btrfs_dev_stat_reset(device, i);
		}

		device->dev_stats_valid = 1;
		btrfs_dev_stat_print_on_load(device);
		btrfs_release_path(path);
	}
	mutex_unlock(&fs_devices->device_list_mutex);

out:
	btrfs_free_path(path);
	return ret < 0 ? ret : 0;
}

static int update_dev_stat_item(struct btrfs_trans_handle *trans,
				struct btrfs_root *dev_root,
				struct btrfs_device *device)
{
	struct btrfs_path *path;
	struct btrfs_key key;
	struct extent_buffer *eb;
	struct btrfs_dev_stats_item *ptr;
	int ret;
	int i;

	key.objectid = 0;
	key.type = BTRFS_DEV_STATS_KEY;
	key.offset = device->devid;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
	if (ret < 0) {
6449 6450
		printk_in_rcu(KERN_WARNING "BTRFS: "
			"error %d while searching for dev_stats item for device %s!\n",
6451
			      ret, rcu_str_deref(device->name));
6452 6453 6454 6455 6456 6457 6458 6459
		goto out;
	}

	if (ret == 0 &&
	    btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
		/* need to delete old one and insert a new one */
		ret = btrfs_del_item(trans, dev_root, path);
		if (ret != 0) {
6460 6461
			printk_in_rcu(KERN_WARNING "BTRFS: "
				"delete too small dev_stats item for device %s failed %d!\n",
6462
				      rcu_str_deref(device->name), ret);
6463 6464 6465 6466 6467 6468 6469 6470 6471 6472 6473
			goto out;
		}
		ret = 1;
	}

	if (ret == 1) {
		/* need to insert a new item */
		btrfs_release_path(path);
		ret = btrfs_insert_empty_item(trans, dev_root, path,
					      &key, sizeof(*ptr));
		if (ret < 0) {
6474 6475
			printk_in_rcu(KERN_WARNING "BTRFS: "
					  "insert dev_stats item for device %s failed %d!\n",
6476
				      rcu_str_deref(device->name), ret);
6477 6478 6479 6480 6481 6482 6483 6484 6485 6486 6487 6488 6489 6490 6491 6492 6493 6494 6495 6496 6497 6498 6499 6500 6501
			goto out;
		}
	}

	eb = path->nodes[0];
	ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
	for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
		btrfs_set_dev_stats_value(eb, ptr, i,
					  btrfs_dev_stat_read(device, i));
	btrfs_mark_buffer_dirty(eb);

out:
	btrfs_free_path(path);
	return ret;
}

/*
 * called from commit_transaction. Writes all changed device stats to disk.
 */
int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
			struct btrfs_fs_info *fs_info)
{
	struct btrfs_root *dev_root = fs_info->dev_root;
	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
	struct btrfs_device *device;
6502
	int stats_cnt;
6503 6504 6505 6506
	int ret = 0;

	mutex_lock(&fs_devices->device_list_mutex);
	list_for_each_entry(device, &fs_devices->devices, dev_list) {
6507
		if (!device->dev_stats_valid || !btrfs_dev_stats_dirty(device))
6508 6509
			continue;

6510
		stats_cnt = atomic_read(&device->dev_stats_ccnt);
6511 6512
		ret = update_dev_stat_item(trans, dev_root, device);
		if (!ret)
6513
			atomic_sub(stats_cnt, &device->dev_stats_ccnt);
6514 6515 6516 6517 6518 6519
	}
	mutex_unlock(&fs_devices->device_list_mutex);

	return ret;
}

6520 6521 6522 6523 6524 6525
void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
{
	btrfs_dev_stat_inc(dev, index);
	btrfs_dev_stat_print_on_error(dev);
}

6526
static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
6527
{
6528 6529
	if (!dev->dev_stats_valid)
		return;
6530 6531
	printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
			   "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6532
			   rcu_str_deref(dev->name),
6533 6534 6535
			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6536 6537
			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
			   btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
6538
}
6539

6540 6541
static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
{
6542 6543 6544 6545 6546 6547 6548 6549
	int i;

	for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
		if (btrfs_dev_stat_read(dev, i) != 0)
			break;
	if (i == BTRFS_DEV_STAT_VALUES_MAX)
		return; /* all values == 0, suppress message */

6550 6551
	printk_in_rcu(KERN_INFO "BTRFS: "
		   "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6552
	       rcu_str_deref(dev->name),
6553 6554 6555 6556 6557 6558 6559
	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
	       btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
}

6560
int btrfs_get_dev_stats(struct btrfs_root *root,
6561
			struct btrfs_ioctl_get_dev_stats *stats)
6562 6563 6564 6565 6566 6567
{
	struct btrfs_device *dev;
	struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
	int i;

	mutex_lock(&fs_devices->device_list_mutex);
6568
	dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
6569 6570 6571
	mutex_unlock(&fs_devices->device_list_mutex);

	if (!dev) {
6572
		btrfs_warn(root->fs_info, "get dev_stats failed, device not found");
6573
		return -ENODEV;
6574
	} else if (!dev->dev_stats_valid) {
6575
		btrfs_warn(root->fs_info, "get dev_stats failed, not yet valid");
6576
		return -ENODEV;
6577
	} else if (stats->flags & BTRFS_DEV_STATS_RESET) {
6578 6579 6580 6581 6582 6583 6584 6585 6586 6587 6588 6589 6590 6591 6592 6593
		for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
			if (stats->nr_items > i)
				stats->values[i] =
					btrfs_dev_stat_read_and_reset(dev, i);
			else
				btrfs_dev_stat_reset(dev, i);
		}
	} else {
		for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
			if (stats->nr_items > i)
				stats->values[i] = btrfs_dev_stat_read(dev, i);
	}
	if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
		stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
	return 0;
}
6594 6595 6596 6597 6598 6599 6600 6601 6602 6603 6604 6605 6606 6607 6608 6609 6610 6611

int btrfs_scratch_superblock(struct btrfs_device *device)
{
	struct buffer_head *bh;
	struct btrfs_super_block *disk_super;

	bh = btrfs_read_dev_super(device->bdev);
	if (!bh)
		return -EINVAL;
	disk_super = (struct btrfs_super_block *)bh->b_data;

	memset(&disk_super->magic, 0, sizeof(disk_super->magic));
	set_buffer_dirty(bh);
	sync_dirty_buffer(bh);
	brelse(bh);

	return 0;
}
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/*
 * Update the size of all devices, which is used for writing out the
 * super blocks.
 */
void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info)
{
	struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
	struct btrfs_device *curr, *next;

	if (list_empty(&fs_devices->resized_devices))
		return;

	mutex_lock(&fs_devices->device_list_mutex);
	lock_chunks(fs_info->dev_root);
	list_for_each_entry_safe(curr, next, &fs_devices->resized_devices,
				 resized_list) {
		list_del_init(&curr->resized_list);
		curr->commit_total_bytes = curr->disk_total_bytes;
	}
	unlock_chunks(fs_info->dev_root);
	mutex_unlock(&fs_devices->device_list_mutex);
}
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/* Must be invoked during the transaction commit */
void btrfs_update_commit_device_bytes_used(struct btrfs_root *root,
					struct btrfs_transaction *transaction)
{
	struct extent_map *em;
	struct map_lookup *map;
	struct btrfs_device *dev;
	int i;

	if (list_empty(&transaction->pending_chunks))
		return;

	/* In order to kick the device replace finish process */
	lock_chunks(root);
	list_for_each_entry(em, &transaction->pending_chunks, list) {
		map = (struct map_lookup *)em->bdev;

		for (i = 0; i < map->num_stripes; i++) {
			dev = map->stripes[i].dev;
			dev->commit_bytes_used = dev->bytes_used;
		}
	}
	unlock_chunks(root);
}