volumes.c 37.5 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/buffer_head.h>
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#include <linux/blkdev.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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struct map_lookup {
	u64 type;
	int io_align;
	int io_width;
	int stripe_len;
	int sector_size;
	int num_stripes;
C
Chris Mason 已提交
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	int sub_stripes;
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	struct btrfs_bio_stripe stripes[];
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};

#define map_lookup_size(n) (sizeof(struct map_lookup) + \
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			    (sizeof(struct btrfs_bio_stripe) * (n)))
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static DEFINE_MUTEX(uuid_mutex);
static LIST_HEAD(fs_uuids);

int btrfs_cleanup_fs_uuids(void)
{
	struct btrfs_fs_devices *fs_devices;
	struct list_head *uuid_cur;
	struct list_head *devices_cur;
	struct btrfs_device *dev;

	list_for_each(uuid_cur, &fs_uuids) {
		fs_devices = list_entry(uuid_cur, struct btrfs_fs_devices,
					list);
		while(!list_empty(&fs_devices->devices)) {
			devices_cur = fs_devices->devices.next;
			dev = list_entry(devices_cur, struct btrfs_device,
					 dev_list);
			if (dev->bdev) {
				close_bdev_excl(dev->bdev);
			}
			list_del(&dev->dev_list);
			kfree(dev);
		}
	}
	return 0;
}

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

	list_for_each(cur, head) {
		dev = list_entry(cur, struct btrfs_device, dev_list);
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		if (dev->devid == devid &&
		    !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE)) {
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			return dev;
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		}
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	}
	return NULL;
}

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

	list_for_each(cur, &fs_uuids) {
		fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
		if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
			return fs_devices;
	}
	return NULL;
}

static int device_list_add(const char *path,
			   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;
	u64 found_transid = btrfs_super_generation(disk_super);

	fs_devices = find_fsid(disk_super->fsid);
	if (!fs_devices) {
		fs_devices = kmalloc(sizeof(*fs_devices), GFP_NOFS);
		if (!fs_devices)
			return -ENOMEM;
		INIT_LIST_HEAD(&fs_devices->devices);
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		INIT_LIST_HEAD(&fs_devices->alloc_list);
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		list_add(&fs_devices->list, &fs_uuids);
		memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
		fs_devices->latest_devid = devid;
		fs_devices->latest_trans = found_transid;
		fs_devices->lowest_devid = (u64)-1;
		fs_devices->num_devices = 0;
		device = NULL;
	} else {
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		device = __find_device(&fs_devices->devices, devid,
				       disk_super->dev_item.uuid);
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	}
	if (!device) {
		device = kzalloc(sizeof(*device), GFP_NOFS);
		if (!device) {
			/* we can safely leave the fs_devices entry around */
			return -ENOMEM;
		}
		device->devid = devid;
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		memcpy(device->uuid, disk_super->dev_item.uuid,
		       BTRFS_UUID_SIZE);
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		device->barriers = 1;
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		spin_lock_init(&device->io_lock);
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		device->name = kstrdup(path, GFP_NOFS);
		if (!device->name) {
			kfree(device);
			return -ENOMEM;
		}
		list_add(&device->dev_list, &fs_devices->devices);
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		list_add(&device->dev_alloc_list, &fs_devices->alloc_list);
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		fs_devices->num_devices++;
	}

	if (found_transid > fs_devices->latest_trans) {
		fs_devices->latest_devid = devid;
		fs_devices->latest_trans = found_transid;
	}
	if (fs_devices->lowest_devid > devid) {
		fs_devices->lowest_devid = devid;
	}
	*fs_devices_ret = fs_devices;
	return 0;
}

int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
{
	struct list_head *head = &fs_devices->devices;
	struct list_head *cur;
	struct btrfs_device *device;

	mutex_lock(&uuid_mutex);
	list_for_each(cur, head) {
		device = list_entry(cur, struct btrfs_device, dev_list);
		if (device->bdev) {
			close_bdev_excl(device->bdev);
		}
		device->bdev = NULL;
	}
	mutex_unlock(&uuid_mutex);
	return 0;
}

int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
		       int flags, void *holder)
{
	struct block_device *bdev;
	struct list_head *head = &fs_devices->devices;
	struct list_head *cur;
	struct btrfs_device *device;
	int ret;

	mutex_lock(&uuid_mutex);
	list_for_each(cur, head) {
		device = list_entry(cur, struct btrfs_device, dev_list);
		bdev = open_bdev_excl(device->name, flags, holder);
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		if (IS_ERR(bdev)) {
			printk("open %s failed\n", device->name);
			ret = PTR_ERR(bdev);
			goto fail;
		}
		if (device->devid == fs_devices->latest_devid)
			fs_devices->latest_bdev = bdev;
		if (device->devid == fs_devices->lowest_devid) {
			fs_devices->lowest_bdev = bdev;
		}
		device->bdev = bdev;
	}
	mutex_unlock(&uuid_mutex);
	return 0;
fail:
	mutex_unlock(&uuid_mutex);
	btrfs_close_devices(fs_devices);
	return ret;
}

int btrfs_scan_one_device(const char *path, int flags, void *holder,
			  struct btrfs_fs_devices **fs_devices_ret)
{
	struct btrfs_super_block *disk_super;
	struct block_device *bdev;
	struct buffer_head *bh;
	int ret;
	u64 devid;
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	u64 transid;
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	mutex_lock(&uuid_mutex);

	bdev = open_bdev_excl(path, flags, holder);

	if (IS_ERR(bdev)) {
		ret = PTR_ERR(bdev);
		goto error;
	}

	ret = set_blocksize(bdev, 4096);
	if (ret)
		goto error_close;
	bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
	if (!bh) {
		ret = -EIO;
		goto error_close;
	}
	disk_super = (struct btrfs_super_block *)bh->b_data;
	if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
	    sizeof(disk_super->magic))) {
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		ret = -EINVAL;
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		goto error_brelse;
	}
	devid = le64_to_cpu(disk_super->dev_item.devid);
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	transid = btrfs_super_generation(disk_super);
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	if (disk_super->label[0])
		printk("device label %s ", disk_super->label);
	else {
		/* FIXME, make a readl uuid parser */
		printk("device fsid %llx-%llx ",
		       *(unsigned long long *)disk_super->fsid,
		       *(unsigned long long *)(disk_super->fsid + 8));
	}
	printk("devid %Lu transid %Lu %s\n", devid, transid, path);
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	ret = device_list_add(path, disk_super, devid, fs_devices_ret);

error_brelse:
	brelse(bh);
error_close:
	close_bdev_excl(bdev);
error:
	mutex_unlock(&uuid_mutex);
	return ret;
}
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/*
 * 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
 */
static int find_free_dev_extent(struct btrfs_trans_handle *trans,
				struct btrfs_device *device,
				struct btrfs_path *path,
				u64 num_bytes, u64 *start)
{
	struct btrfs_key key;
	struct btrfs_root *root = device->dev_root;
	struct btrfs_dev_extent *dev_extent = NULL;
	u64 hole_size = 0;
	u64 last_byte = 0;
	u64 search_start = 0;
	u64 search_end = device->total_bytes;
	int ret;
	int slot = 0;
	int start_found;
	struct extent_buffer *l;

	start_found = 0;
	path->reada = 2;

	/* FIXME use last free of some kind */

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	/* we don't want to overwrite the superblock on the drive,
	 * so we make sure to start at an offset of at least 1MB
	 */
	search_start = max((u64)1024 * 1024, search_start);
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	key.objectid = device->devid;
	key.offset = search_start;
	key.type = BTRFS_DEV_EXTENT_KEY;
	ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
	if (ret < 0)
		goto error;
	ret = btrfs_previous_item(root, path, 0, key.type);
	if (ret < 0)
		goto error;
	l = path->nodes[0];
	btrfs_item_key_to_cpu(l, &key, path->slots[0]);
	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 error;
no_more_items:
			if (!start_found) {
				if (search_start >= search_end) {
					ret = -ENOSPC;
					goto error;
				}
				*start = search_start;
				start_found = 1;
				goto check_pending;
			}
			*start = last_byte > search_start ?
				last_byte : search_start;
			if (search_end <= *start) {
				ret = -ENOSPC;
				goto error;
			}
			goto check_pending;
		}
		btrfs_item_key_to_cpu(l, &key, slot);

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

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

		if (key.offset >= search_start && key.offset > last_byte &&
		    start_found) {
			if (last_byte < search_start)
				last_byte = search_start;
			hole_size = key.offset - last_byte;
			if (key.offset > last_byte &&
			    hole_size >= num_bytes) {
				*start = last_byte;
				goto check_pending;
			}
		}
		if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
			goto next;
		}

		start_found = 1;
		dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
		last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
next:
		path->slots[0]++;
		cond_resched();
	}
check_pending:
	/* we have to make sure we didn't find an extent that has already
	 * been allocated by the map tree or the original allocation
	 */
	btrfs_release_path(root, path);
	BUG_ON(*start < search_start);

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	if (*start + num_bytes > search_end) {
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		ret = -ENOSPC;
		goto error;
	}
	/* check for pending inserts here */
	return 0;

error:
	btrfs_release_path(root, path);
	return ret;
}

int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
			   struct btrfs_device *device,
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			   u64 chunk_tree, u64 chunk_objectid,
			   u64 chunk_offset,
			   u64 num_bytes, u64 *start)
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{
	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;

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

	ret = find_free_dev_extent(trans, device, path, num_bytes, start);
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	if (ret) {
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		goto err;
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	}
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	key.objectid = device->devid;
	key.offset = *start;
	key.type = BTRFS_DEV_EXTENT_KEY;
	ret = btrfs_insert_empty_item(trans, root, path, &key,
				      sizeof(*extent));
	BUG_ON(ret);

	leaf = path->nodes[0];
	extent = btrfs_item_ptr(leaf, path->slots[0],
				struct btrfs_dev_extent);
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	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,
		    (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
		    BTRFS_UUID_SIZE);

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	btrfs_set_dev_extent_length(leaf, extent, num_bytes);
	btrfs_mark_buffer_dirty(leaf);
err:
	btrfs_free_path(path);
	return ret;
}

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static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset)
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{
	struct btrfs_path *path;
	int ret;
	struct btrfs_key key;
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	struct btrfs_chunk *chunk;
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	struct btrfs_key found_key;

	path = btrfs_alloc_path();
	BUG_ON(!path);

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

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto error;

	BUG_ON(ret == 0);

	ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
	if (ret) {
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		*offset = 0;
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	} else {
		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
				      path->slots[0]);
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		if (found_key.objectid != objectid)
			*offset = 0;
		else {
			chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
					       struct btrfs_chunk);
			*offset = found_key.offset +
				btrfs_chunk_length(path->nodes[0], chunk);
		}
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	}
	ret = 0;
error:
	btrfs_free_path(path);
	return ret;
}

static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
			   u64 *objectid)
{
	int ret;
	struct btrfs_key key;
	struct btrfs_key found_key;

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

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto error;

	BUG_ON(ret == 0);

	ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
				  BTRFS_DEV_ITEM_KEY);
	if (ret) {
		*objectid = 1;
	} else {
		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
				      path->slots[0]);
		*objectid = found_key.offset + 1;
	}
	ret = 0;
error:
	btrfs_release_path(root, path);
	return ret;
}

/*
 * the device information is stored in the chunk root
 * the btrfs_device struct should be fully filled in
 */
int btrfs_add_device(struct btrfs_trans_handle *trans,
		     struct btrfs_root *root,
		     struct btrfs_device *device)
{
	int ret;
	struct btrfs_path *path;
	struct btrfs_dev_item *dev_item;
	struct extent_buffer *leaf;
	struct btrfs_key key;
	unsigned long ptr;
	u64 free_devid;

	root = root->fs_info->chunk_root;

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

	ret = find_next_devid(root, path, &free_devid);
	if (ret)
		goto out;

	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.type = BTRFS_DEV_ITEM_KEY;
	key.offset = free_devid;

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

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

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	device->devid = free_devid;
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	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);
	btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
	btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
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	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);
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	ptr = (unsigned long)btrfs_device_uuid(dev_item);
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	write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
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	btrfs_mark_buffer_dirty(leaf);
	ret = 0;

out:
	btrfs_free_path(path);
	return ret;
}
int btrfs_update_device(struct btrfs_trans_handle *trans,
			struct btrfs_device *device)
{
	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);
	btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
	btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
	btrfs_mark_buffer_dirty(leaf);

out:
	btrfs_free_path(path);
	return ret;
}

int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root,
			   struct btrfs_key *key,
			   struct btrfs_chunk *chunk, int item_size)
{
	struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
	struct btrfs_disk_key disk_key;
	u32 array_size;
	u8 *ptr;

	array_size = btrfs_super_sys_array_size(super_copy);
	if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
		return -EFBIG;

	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);
	return 0;
}

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static u64 div_factor(u64 num, int factor)
{
	if (factor == 10)
		return num;
	num *= factor;
	do_div(num, 10);
	return num;
}

static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
			       int sub_stripes)
{
	if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
		return calc_size;
	else if (type & BTRFS_BLOCK_GROUP_RAID10)
		return calc_size * (num_stripes / sub_stripes);
	else
		return calc_size * num_stripes;
}


654 655
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
		      struct btrfs_root *extent_root, u64 *start,
656
		      u64 *num_bytes, u64 type)
657 658
{
	u64 dev_offset;
659
	struct btrfs_fs_info *info = extent_root->fs_info;
660 661 662 663
	struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
	struct btrfs_stripe *stripes;
	struct btrfs_device *device = NULL;
	struct btrfs_chunk *chunk;
664
	struct list_head private_devs;
665
	struct list_head *dev_list;
666
	struct list_head *cur;
667 668 669
	struct extent_map_tree *em_tree;
	struct map_lookup *map;
	struct extent_map *em;
670
	int min_stripe_size = 1 * 1024 * 1024;
671 672
	u64 physical;
	u64 calc_size = 1024 * 1024 * 1024;
673 674
	u64 max_chunk_size = calc_size;
	u64 min_free;
675 676
	u64 avail;
	u64 max_avail = 0;
677
	u64 percent_max;
678
	int num_stripes = 1;
679
	int min_stripes = 1;
C
Chris Mason 已提交
680
	int sub_stripes = 0;
681
	int looped = 0;
682
	int ret;
683
	int index;
684
	int stripe_len = 64 * 1024;
685 686
	struct btrfs_key key;

687
	dev_list = &extent_root->fs_info->fs_devices->alloc_list;
688 689
	if (list_empty(dev_list))
		return -ENOSPC;
690

691
	if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
692
		num_stripes = btrfs_super_num_devices(&info->super_copy);
693 694 695
		min_stripes = 2;
	}
	if (type & (BTRFS_BLOCK_GROUP_DUP)) {
696
		num_stripes = 2;
697 698
		min_stripes = 2;
	}
699 700 701
	if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
		num_stripes = min_t(u64, 2,
				  btrfs_super_num_devices(&info->super_copy));
702 703
		if (num_stripes < 2)
			return -ENOSPC;
704
		min_stripes = 2;
705
	}
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Chris Mason 已提交
706 707 708 709 710 711
	if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
		num_stripes = btrfs_super_num_devices(&info->super_copy);
		if (num_stripes < 4)
			return -ENOSPC;
		num_stripes &= ~(u32)1;
		sub_stripes = 2;
712
		min_stripes = 4;
C
Chris Mason 已提交
713
	}
714 715 716

	if (type & BTRFS_BLOCK_GROUP_DATA) {
		max_chunk_size = 10 * calc_size;
717
		min_stripe_size = 64 * 1024 * 1024;
718 719
	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
		max_chunk_size = 4 * calc_size;
720 721 722 723 724
		min_stripe_size = 32 * 1024 * 1024;
	} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
		calc_size = 8 * 1024 * 1024;
		max_chunk_size = calc_size * 2;
		min_stripe_size = 1 * 1024 * 1024;
725 726 727 728 729 730
	}

	/* we don't want a chunk larger than 10% of the FS */
	percent_max = div_factor(btrfs_super_total_bytes(&info->super_copy), 1);
	max_chunk_size = min(percent_max, max_chunk_size);

731
again:
732 733 734 735 736 737 738
	if (calc_size * num_stripes > max_chunk_size) {
		calc_size = max_chunk_size;
		do_div(calc_size, num_stripes);
		do_div(calc_size, stripe_len);
		calc_size *= stripe_len;
	}
	/* we don't want tiny stripes */
739
	calc_size = max_t(u64, min_stripe_size, calc_size);
740 741 742 743

	do_div(calc_size, stripe_len);
	calc_size *= stripe_len;

744 745 746
	INIT_LIST_HEAD(&private_devs);
	cur = dev_list->next;
	index = 0;
747 748 749

	if (type & BTRFS_BLOCK_GROUP_DUP)
		min_free = calc_size * 2;
750 751
	else
		min_free = calc_size;
752

753 754 755
	/* we add 1MB because we never use the first 1MB of the device */
	min_free += 1024 * 1024;

756 757
	/* build a private list of devices we will allocate from */
	while(index < num_stripes) {
758
		device = list_entry(cur, struct btrfs_device, dev_alloc_list);
759

760 761
		avail = device->total_bytes - device->bytes_used;
		cur = cur->next;
762
		if (avail >= min_free) {
763
			list_move_tail(&device->dev_alloc_list, &private_devs);
764
			index++;
765 766
			if (type & BTRFS_BLOCK_GROUP_DUP)
				index++;
767 768
		} else if (avail > max_avail)
			max_avail = avail;
769 770 771 772 773
		if (cur == dev_list)
			break;
	}
	if (index < num_stripes) {
		list_splice(&private_devs, dev_list);
774 775 776 777 778 779 780 781 782
		if (index >= min_stripes) {
			num_stripes = index;
			if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
				num_stripes /= sub_stripes;
				num_stripes *= sub_stripes;
			}
			looped = 1;
			goto again;
		}
783 784 785 786 787 788 789
		if (!looped && max_avail > 0) {
			looped = 1;
			calc_size = max_avail;
			goto again;
		}
		return -ENOSPC;
	}
790 791 792 793
	key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
	key.type = BTRFS_CHUNK_ITEM_KEY;
	ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
			      &key.offset);
794 795 796 797 798 799 800
	if (ret)
		return ret;

	chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
	if (!chunk)
		return -ENOMEM;

801 802 803 804 805 806
	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
	if (!map) {
		kfree(chunk);
		return -ENOMEM;
	}

807
	stripes = &chunk->stripe;
808 809
	*num_bytes = chunk_bytes_by_type(type, calc_size,
					 num_stripes, sub_stripes);
810

811

812
	index = 0;
813
printk("new chunk type %Lu start %Lu size %Lu\n", type, key.offset, *num_bytes);
814
	while(index < num_stripes) {
815
		struct btrfs_stripe *stripe;
816 817
		BUG_ON(list_empty(&private_devs));
		cur = private_devs.next;
818
		device = list_entry(cur, struct btrfs_device, dev_alloc_list);
819 820 821 822

		/* loop over this device again if we're doing a dup group */
		if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
		    (index == num_stripes - 1))
823
			list_move_tail(&device->dev_alloc_list, dev_list);
824 825

		ret = btrfs_alloc_dev_extent(trans, device,
826 827 828
			     info->chunk_root->root_key.objectid,
			     BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
			     calc_size, &dev_offset);
829
		BUG_ON(ret);
830
printk("alloc chunk start %Lu size %Lu from dev %Lu type %Lu\n", key.offset, calc_size, device->devid, type);
831 832 833 834
		device->bytes_used += calc_size;
		ret = btrfs_update_device(trans, device);
		BUG_ON(ret);

835 836
		map->stripes[index].dev = device;
		map->stripes[index].physical = dev_offset;
837 838 839 840
		stripe = stripes + index;
		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);
841 842 843
		physical = dev_offset;
		index++;
	}
844
	BUG_ON(!list_empty(&private_devs));
845

846 847
	/* key was set above */
	btrfs_set_stack_chunk_length(chunk, *num_bytes);
848
	btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
849
	btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
850 851
	btrfs_set_stack_chunk_type(chunk, type);
	btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
852 853
	btrfs_set_stack_chunk_io_align(chunk, stripe_len);
	btrfs_set_stack_chunk_io_width(chunk, stripe_len);
854
	btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
C
Chris Mason 已提交
855
	btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
856 857 858 859 860 861
	map->sector_size = extent_root->sectorsize;
	map->stripe_len = stripe_len;
	map->io_align = stripe_len;
	map->io_width = stripe_len;
	map->type = type;
	map->num_stripes = num_stripes;
C
Chris Mason 已提交
862
	map->sub_stripes = sub_stripes;
863 864 865 866

	ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
				btrfs_chunk_item_size(num_stripes));
	BUG_ON(ret);
867
	*start = key.offset;;
868 869 870 871 872

	em = alloc_extent_map(GFP_NOFS);
	if (!em)
		return -ENOMEM;
	em->bdev = (struct block_device *)map;
873 874
	em->start = key.offset;
	em->len = *num_bytes;
875 876 877 878 879 880 881 882
	em->block_start = 0;

	kfree(chunk);

	em_tree = &extent_root->fs_info->mapping_tree.map_tree;
	spin_lock(&em_tree->lock);
	ret = add_extent_mapping(em_tree, em);
	spin_unlock(&em_tree->lock);
883
	BUG_ON(ret);
884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912
	free_extent_map(em);
	return ret;
}

void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
{
	extent_map_tree_init(&tree->map_tree, GFP_NOFS);
}

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

	while(1) {
		spin_lock(&tree->map_tree.lock);
		em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
		if (em)
			remove_extent_mapping(&tree->map_tree, em);
		spin_unlock(&tree->map_tree.lock);
		if (!em)
			break;
		kfree(em->bdev);
		/* once for us */
		free_extent_map(em);
		/* once for the tree */
		free_extent_map(em);
	}
}

913 914 915 916 917 918 919 920 921
int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
{
	struct extent_map *em;
	struct map_lookup *map;
	struct extent_map_tree *em_tree = &map_tree->map_tree;
	int ret;

	spin_lock(&em_tree->lock);
	em = lookup_extent_mapping(em_tree, logical, len);
922
	spin_unlock(&em_tree->lock);
923 924 925 926 927 928
	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_DUP | BTRFS_BLOCK_GROUP_RAID1))
		ret = map->num_stripes;
C
Chris Mason 已提交
929 930
	else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
		ret = map->sub_stripes;
931 932 933 934 935 936
	else
		ret = 1;
	free_extent_map(em);
	return ret;
}

937 938 939 940
static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
			     u64 logical, u64 *length,
			     struct btrfs_multi_bio **multi_ret,
			     int mirror_num, struct page *unplug_page)
941 942 943 944 945
{
	struct extent_map *em;
	struct map_lookup *map;
	struct extent_map_tree *em_tree = &map_tree->map_tree;
	u64 offset;
946 947
	u64 stripe_offset;
	u64 stripe_nr;
948
	int stripes_allocated = 8;
C
Chris Mason 已提交
949
	int stripes_required = 1;
950
	int stripe_index;
951
	int i;
952
	int num_stripes;
953
	struct btrfs_multi_bio *multi = NULL;
954

955 956 957 958 959 960 961 962 963 964
	if (multi_ret && !(rw & (1 << BIO_RW))) {
		stripes_allocated = 1;
	}
again:
	if (multi_ret) {
		multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
				GFP_NOFS);
		if (!multi)
			return -ENOMEM;
	}
965 966 967

	spin_lock(&em_tree->lock);
	em = lookup_extent_mapping(em_tree, logical, *length);
968
	spin_unlock(&em_tree->lock);
969 970 971 972

	if (!em && unplug_page)
		return 0;

973 974
	if (!em) {
		printk("unable to find logical %Lu\n", logical);
975
		BUG();
976
	}
977 978 979 980

	BUG_ON(em->start > logical || em->start + em->len < logical);
	map = (struct map_lookup *)em->bdev;
	offset = logical - em->start;
981

982 983 984
	if (mirror_num > map->num_stripes)
		mirror_num = 0;

985
	/* if our multi bio struct is too small, back off and try again */
C
Chris Mason 已提交
986 987 988 989 990 991 992 993 994 995
	if (rw & (1 << BIO_RW)) {
		if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
				 BTRFS_BLOCK_GROUP_DUP)) {
			stripes_required = map->num_stripes;
		} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
			stripes_required = map->sub_stripes;
		}
	}
	if (multi_ret && rw == WRITE &&
	    stripes_allocated < stripes_required) {
996 997 998 999 1000
		stripes_allocated = map->num_stripes;
		free_extent_map(em);
		kfree(multi);
		goto again;
	}
1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013
	stripe_nr = offset;
	/*
	 * stripe_nr counts the total number of stripes we have to stride
	 * to get to this block
	 */
	do_div(stripe_nr, map->stripe_len);

	stripe_offset = stripe_nr * map->stripe_len;
	BUG_ON(offset < stripe_offset);

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

1014
	if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
C
Chris Mason 已提交
1015
			 BTRFS_BLOCK_GROUP_RAID10 |
1016 1017 1018 1019 1020 1021 1022
			 BTRFS_BLOCK_GROUP_DUP)) {
		/* we limit the length of each bio to what fits in a stripe */
		*length = min_t(u64, em->len - offset,
			      map->stripe_len - stripe_offset);
	} else {
		*length = em->len - offset;
	}
1023 1024

	if (!multi_ret && !unplug_page)
1025 1026
		goto out;

1027
	num_stripes = 1;
1028
	stripe_index = 0;
1029
	if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1030 1031
		if (unplug_page || (rw & (1 << BIO_RW)))
			num_stripes = map->num_stripes;
1032 1033 1034
		else if (mirror_num) {
			stripe_index = mirror_num - 1;
		} else {
1035 1036
			u64 orig_stripe_nr = stripe_nr;
			stripe_index = do_div(orig_stripe_nr, num_stripes);
1037
		}
1038
	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1039
		if (rw & (1 << BIO_RW))
1040
			num_stripes = map->num_stripes;
1041 1042
		else if (mirror_num)
			stripe_index = mirror_num - 1;
C
Chris Mason 已提交
1043 1044 1045 1046 1047 1048
	} 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;

1049 1050
		if (unplug_page || (rw & (1 << BIO_RW)))
			num_stripes = map->sub_stripes;
C
Chris Mason 已提交
1051 1052
		else if (mirror_num)
			stripe_index += mirror_num - 1;
1053 1054 1055 1056 1057
		else {
			u64 orig_stripe_nr = stripe_nr;
			stripe_index += do_div(orig_stripe_nr,
					       map->sub_stripes);
		}
1058 1059 1060 1061 1062 1063 1064 1065
	} 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);
	}
1066
	BUG_ON(stripe_index >= map->num_stripes);
1067

1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083
	for (i = 0; i < num_stripes; i++) {
		if (unplug_page) {
			struct btrfs_device *device;
			struct backing_dev_info *bdi;

			device = map->stripes[stripe_index].dev;
			bdi = blk_get_backing_dev_info(device->bdev);
			if (bdi->unplug_io_fn) {
				bdi->unplug_io_fn(bdi, unplug_page);
			}
		} else {
			multi->stripes[i].physical =
				map->stripes[stripe_index].physical +
				stripe_offset + stripe_nr * map->stripe_len;
			multi->stripes[i].dev = map->stripes[stripe_index].dev;
		}
1084
		stripe_index++;
1085
	}
1086 1087 1088 1089
	if (multi_ret) {
		*multi_ret = multi;
		multi->num_stripes = num_stripes;
	}
1090
out:
1091 1092 1093 1094
	free_extent_map(em);
	return 0;
}

1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111
int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
		      u64 logical, u64 *length,
		      struct btrfs_multi_bio **multi_ret, int mirror_num)
{
	return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
				 mirror_num, NULL);
}

int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
		      u64 logical, struct page *page)
{
	u64 length = PAGE_CACHE_SIZE;
	return __btrfs_map_block(map_tree, READ, logical, &length,
				 NULL, 0, page);
}


1112 1113 1114 1115 1116 1117 1118
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
static void end_bio_multi_stripe(struct bio *bio, int err)
#else
static int end_bio_multi_stripe(struct bio *bio,
				   unsigned int bytes_done, int err)
#endif
{
1119
	struct btrfs_multi_bio *multi = bio->bi_private;
1120 1121 1122 1123 1124 1125 1126 1127

#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
	if (bio->bi_size)
		return 1;
#endif
	if (err)
		multi->error = err;

1128
	if (atomic_dec_and_test(&multi->stripes_pending)) {
1129 1130 1131 1132 1133 1134 1135
		bio->bi_private = multi->private;
		bio->bi_end_io = multi->end_io;

		if (!err && multi->error)
			err = multi->error;
		kfree(multi);

1136 1137 1138
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
		bio_endio(bio, bio->bi_size, err);
#else
1139
		bio_endio(bio, err);
1140
#endif
1141 1142 1143 1144 1145 1146 1147 1148
	} else {
		bio_put(bio);
	}
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
	return 0;
#endif
}

1149 1150
int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
		  int mirror_num)
1151 1152 1153
{
	struct btrfs_mapping_tree *map_tree;
	struct btrfs_device *dev;
1154
	struct bio *first_bio = bio;
1155 1156 1157
	u64 logical = bio->bi_sector << 9;
	u64 length = 0;
	u64 map_length;
1158
	struct btrfs_multi_bio *multi = NULL;
1159
	int ret;
1160 1161
	int dev_nr = 0;
	int total_devs = 1;
1162

1163
	length = bio->bi_size;
1164 1165
	map_tree = &root->fs_info->mapping_tree;
	map_length = length;
1166

1167 1168
	ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
			      mirror_num);
1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180
	BUG_ON(ret);

	total_devs = multi->num_stripes;
	if (map_length < length) {
		printk("mapping failed logical %Lu bio len %Lu "
		       "len %Lu\n", logical, length, map_length);
		BUG();
	}
	multi->end_io = first_bio->bi_end_io;
	multi->private = first_bio->bi_private;
	atomic_set(&multi->stripes_pending, multi->num_stripes);

1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191
	while(dev_nr < total_devs) {
		if (total_devs > 1) {
			if (dev_nr < total_devs - 1) {
				bio = bio_clone(first_bio, GFP_NOFS);
				BUG_ON(!bio);
			} else {
				bio = first_bio;
			}
			bio->bi_private = multi;
			bio->bi_end_io = end_bio_multi_stripe;
		}
1192 1193
		bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
		dev = multi->stripes[dev_nr].dev;
1194

1195 1196 1197 1198 1199 1200 1201
		bio->bi_bdev = dev->bdev;
		spin_lock(&dev->io_lock);
		dev->total_ios++;
		spin_unlock(&dev->io_lock);
		submit_bio(rw, bio);
		dev_nr++;
	}
1202 1203
	if (total_devs == 1)
		kfree(multi);
1204 1205 1206
	return 0;
}

1207 1208
struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
				       u8 *uuid)
1209
{
1210
	struct list_head *head = &root->fs_info->fs_devices->devices;
1211

1212
	return __find_device(head, devid, uuid);
1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224
}

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;
1225
	u8 uuid[BTRFS_UUID_SIZE];
1226
	int num_stripes;
1227
	int ret;
1228
	int i;
1229

1230 1231
	logical = key->offset;
	length = btrfs_chunk_length(leaf, chunk);
1232 1233
	spin_lock(&map_tree->map_tree.lock);
	em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
1234
	spin_unlock(&map_tree->map_tree.lock);
1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250

	/* 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);
	}

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

	em = alloc_extent_map(GFP_NOFS);
	if (!em)
		return -ENOMEM;
1251 1252
	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1253 1254 1255 1256 1257 1258 1259 1260 1261 1262
	if (!map) {
		free_extent_map(em);
		return -ENOMEM;
	}

	em->bdev = (struct block_device *)map;
	em->start = logical;
	em->len = length;
	em->block_start = 0;

1263 1264 1265 1266 1267 1268
	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
1269
	map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
1270 1271 1272 1273
	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);
1274 1275 1276 1277
		read_extent_buffer(leaf, uuid, (unsigned long)
				   btrfs_stripe_dev_uuid_nr(chunk, i),
				   BTRFS_UUID_SIZE);
		map->stripes[i].dev = btrfs_find_device(root, devid, uuid);
1278 1279 1280 1281 1282
		if (!map->stripes[i].dev) {
			kfree(map);
			free_extent_map(em);
			return -EIO;
		}
1283 1284 1285 1286 1287
	}

	spin_lock(&map_tree->map_tree.lock);
	ret = add_extent_mapping(&map_tree->map_tree, em);
	spin_unlock(&map_tree->map_tree.lock);
1288
	BUG_ON(ret);
1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308
	free_extent_map(em);

	return 0;
}

static int fill_device_from_item(struct extent_buffer *leaf,
				 struct btrfs_dev_item *dev_item,
				 struct btrfs_device *device)
{
	unsigned long ptr;

	device->devid = btrfs_device_id(leaf, dev_item);
	device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
	device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
	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);

	ptr = (unsigned long)btrfs_device_uuid(dev_item);
1309
	read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1310 1311 1312 1313

	return 0;
}

1314
static int read_one_dev(struct btrfs_root *root,
1315 1316 1317 1318 1319 1320
			struct extent_buffer *leaf,
			struct btrfs_dev_item *dev_item)
{
	struct btrfs_device *device;
	u64 devid;
	int ret;
1321 1322
	u8 dev_uuid[BTRFS_UUID_SIZE];

1323
	devid = btrfs_device_id(leaf, dev_item);
1324 1325 1326 1327
	read_extent_buffer(leaf, dev_uuid,
			   (unsigned long)btrfs_device_uuid(dev_item),
			   BTRFS_UUID_SIZE);
	device = btrfs_find_device(root, devid, dev_uuid);
1328
	if (!device) {
1329
		printk("warning devid %Lu not found already\n", devid);
1330
		device = kzalloc(sizeof(*device), GFP_NOFS);
1331 1332
		if (!device)
			return -ENOMEM;
1333 1334
		list_add(&device->dev_list,
			 &root->fs_info->fs_devices->devices);
1335 1336
		list_add(&device->dev_alloc_list,
			 &root->fs_info->fs_devices->alloc_list);
1337
		device->barriers = 1;
1338
		spin_lock_init(&device->io_lock);
1339
	}
1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352

	fill_device_from_item(leaf, dev_item, device);
	device->dev_root = root->fs_info->dev_root;
	ret = 0;
#if 0
	ret = btrfs_open_device(device);
	if (ret) {
		kfree(device);
	}
#endif
	return ret;
}

1353 1354 1355 1356 1357 1358 1359 1360 1361
int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
{
	struct btrfs_dev_item *dev_item;

	dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
						     dev_item);
	return read_one_dev(root, buf, dev_item);
}

1362 1363 1364 1365 1366 1367
int btrfs_read_sys_array(struct btrfs_root *root)
{
	struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
	struct extent_buffer *sb = root->fs_info->sb_buffer;
	struct btrfs_disk_key *disk_key;
	struct btrfs_chunk *chunk;
1368 1369 1370
	u8 *ptr;
	unsigned long sb_ptr;
	int ret = 0;
1371 1372 1373 1374
	u32 num_stripes;
	u32 array_size;
	u32 len = 0;
	u32 cur;
1375
	struct btrfs_key key;
1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396

	array_size = btrfs_super_sys_array_size(super_copy);

	/*
	 * we do this loop twice, once for the device items and
	 * once for all of the chunks.  This way there are device
	 * structs filled in for every chunk
	 */
	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);

		len = sizeof(*disk_key);
		ptr += len;
		sb_ptr += len;
		cur += len;

1397
		if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1398
			chunk = (struct btrfs_chunk *)sb_ptr;
1399
			ret = read_one_chunk(root, &key, sb, chunk);
1400 1401
			if (ret)
				break;
1402 1403 1404
			num_stripes = btrfs_chunk_num_stripes(sb, chunk);
			len = btrfs_chunk_item_size(num_stripes);
		} else {
1405 1406
			ret = -EIO;
			break;
1407 1408 1409 1410 1411
		}
		ptr += len;
		sb_ptr += len;
		cur += len;
	}
1412
	return ret;
1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457
}

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;

	/* first we search for all of the device items, and then we
	 * read in all of the chunk items.  This way we can create chunk
	 * mappings that reference all of the devices that are afound
	 */
	key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
	key.offset = 0;
	key.type = 0;
again:
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	while(1) {
		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);
		if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
			if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
				break;
			if (found_key.type == BTRFS_DEV_ITEM_KEY) {
				struct btrfs_dev_item *dev_item;
				dev_item = btrfs_item_ptr(leaf, slot,
						  struct btrfs_dev_item);
1458
				ret = read_one_dev(root, leaf, dev_item);
1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479
				BUG_ON(ret);
			}
		} 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);
		}
		path->slots[0]++;
	}
	if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
		key.objectid = 0;
		btrfs_release_path(root, path);
		goto again;
	}

	btrfs_free_path(path);
	ret = 0;
error:
	return ret;
}