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);
		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);
		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;
}


652 653
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
		      struct btrfs_root *extent_root, u64 *start,
654
		      u64 *num_bytes, u64 type)
655 656
{
	u64 dev_offset;
657
	struct btrfs_fs_info *info = extent_root->fs_info;
658 659 660 661
	struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
	struct btrfs_stripe *stripes;
	struct btrfs_device *device = NULL;
	struct btrfs_chunk *chunk;
662
	struct list_head private_devs;
663
	struct list_head *dev_list = &extent_root->fs_info->fs_devices->devices;
664
	struct list_head *cur;
665 666 667
	struct extent_map_tree *em_tree;
	struct map_lookup *map;
	struct extent_map *em;
668
	int min_stripe_size = 1 * 1024 * 1024;
669 670
	u64 physical;
	u64 calc_size = 1024 * 1024 * 1024;
671 672
	u64 max_chunk_size = calc_size;
	u64 min_free;
673 674
	u64 avail;
	u64 max_avail = 0;
675
	u64 percent_max;
676
	int num_stripes = 1;
677
	int min_stripes = 1;
C
Chris Mason 已提交
678
	int sub_stripes = 0;
679
	int looped = 0;
680
	int ret;
681
	int index;
682
	int stripe_len = 64 * 1024;
683 684
	struct btrfs_key key;

685 686
	if (list_empty(dev_list))
		return -ENOSPC;
687

688
	if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
689
		num_stripes = btrfs_super_num_devices(&info->super_copy);
690 691 692
		min_stripes = 2;
	}
	if (type & (BTRFS_BLOCK_GROUP_DUP)) {
693
		num_stripes = 2;
694 695
		min_stripes = 2;
	}
696 697 698
	if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
		num_stripes = min_t(u64, 2,
				  btrfs_super_num_devices(&info->super_copy));
699 700
		if (num_stripes < 2)
			return -ENOSPC;
701
		min_stripes = 2;
702
	}
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703 704 705 706 707 708
	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;
709
		min_stripes = 4;
C
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710
	}
711 712 713

	if (type & BTRFS_BLOCK_GROUP_DATA) {
		max_chunk_size = 10 * calc_size;
714
		min_stripe_size = 64 * 1024 * 1024;
715 716
	} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
		max_chunk_size = 4 * calc_size;
717 718 719 720 721
		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;
722 723 724 725 726 727
	}

	/* 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);

728
again:
729 730 731 732 733 734 735
	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 */
736
	calc_size = max_t(u64, min_stripe_size, calc_size);
737 738 739 740

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

741 742 743
	INIT_LIST_HEAD(&private_devs);
	cur = dev_list->next;
	index = 0;
744 745 746

	if (type & BTRFS_BLOCK_GROUP_DUP)
		min_free = calc_size * 2;
747 748
	else
		min_free = calc_size;
749

750 751 752
	/* we add 1MB because we never use the first 1MB of the device */
	min_free += 1024 * 1024;

753 754 755
	/* build a private list of devices we will allocate from */
	while(index < num_stripes) {
		device = list_entry(cur, struct btrfs_device, dev_list);
756

757 758
		avail = device->total_bytes - device->bytes_used;
		cur = cur->next;
759
		if (avail >= min_free) {
760 761
			list_move_tail(&device->dev_list, &private_devs);
			index++;
762 763
			if (type & BTRFS_BLOCK_GROUP_DUP)
				index++;
764 765
		} else if (avail > max_avail)
			max_avail = avail;
766 767 768 769 770
		if (cur == dev_list)
			break;
	}
	if (index < num_stripes) {
		list_splice(&private_devs, dev_list);
771 772 773 774 775 776 777 778 779
		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;
		}
780 781 782 783 784 785 786
		if (!looped && max_avail > 0) {
			looped = 1;
			calc_size = max_avail;
			goto again;
		}
		return -ENOSPC;
	}
787 788 789 790
	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);
791 792 793 794 795 796 797
	if (ret)
		return ret;

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

798 799 800 801 802 803
	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
	if (!map) {
		kfree(chunk);
		return -ENOMEM;
	}

804
	stripes = &chunk->stripe;
805 806
	*num_bytes = chunk_bytes_by_type(type, calc_size,
					 num_stripes, sub_stripes);
807

808

809
	index = 0;
810
printk("new chunk type %Lu start %Lu size %Lu\n", type, key.offset, *num_bytes);
811
	while(index < num_stripes) {
812
		struct btrfs_stripe *stripe;
813 814 815
		BUG_ON(list_empty(&private_devs));
		cur = private_devs.next;
		device = list_entry(cur, struct btrfs_device, dev_list);
816 817 818 819 820

		/* loop over this device again if we're doing a dup group */
		if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
		    (index == num_stripes - 1))
			list_move_tail(&device->dev_list, dev_list);
821 822

		ret = btrfs_alloc_dev_extent(trans, device,
823 824 825
			     info->chunk_root->root_key.objectid,
			     BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
			     calc_size, &dev_offset);
826
		BUG_ON(ret);
827
printk("alloc chunk start %Lu size %Lu from dev %Lu type %Lu\n", key.offset, calc_size, device->devid, type);
828 829 830 831
		device->bytes_used += calc_size;
		ret = btrfs_update_device(trans, device);
		BUG_ON(ret);

832 833
		map->stripes[index].dev = device;
		map->stripes[index].physical = dev_offset;
834 835 836 837
		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);
838 839 840
		physical = dev_offset;
		index++;
	}
841
	BUG_ON(!list_empty(&private_devs));
842

843 844
	/* key was set above */
	btrfs_set_stack_chunk_length(chunk, *num_bytes);
845
	btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
846
	btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
847 848
	btrfs_set_stack_chunk_type(chunk, type);
	btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
849 850
	btrfs_set_stack_chunk_io_align(chunk, stripe_len);
	btrfs_set_stack_chunk_io_width(chunk, stripe_len);
851
	btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
C
Chris Mason 已提交
852
	btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
853 854 855 856 857 858
	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
859
	map->sub_stripes = sub_stripes;
860 861 862 863

	ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
				btrfs_chunk_item_size(num_stripes));
	BUG_ON(ret);
864
	*start = key.offset;;
865 866 867 868 869

	em = alloc_extent_map(GFP_NOFS);
	if (!em)
		return -ENOMEM;
	em->bdev = (struct block_device *)map;
870 871
	em->start = key.offset;
	em->len = *num_bytes;
872 873 874 875 876 877 878 879
	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);
880
	BUG_ON(ret);
881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909
	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);
	}
}

910 911 912 913 914 915 916 917 918
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);
919
	spin_unlock(&em_tree->lock);
920 921 922 923 924 925
	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
926 927
	else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
		ret = map->sub_stripes;
928 929 930 931 932 933
	else
		ret = 1;
	free_extent_map(em);
	return ret;
}

934 935 936 937
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)
938 939 940 941 942
{
	struct extent_map *em;
	struct map_lookup *map;
	struct extent_map_tree *em_tree = &map_tree->map_tree;
	u64 offset;
943 944
	u64 stripe_offset;
	u64 stripe_nr;
945
	int stripes_allocated = 8;
C
Chris Mason 已提交
946
	int stripes_required = 1;
947
	int stripe_index;
948
	int i;
949
	int num_stripes;
950
	struct btrfs_multi_bio *multi = NULL;
951

952 953 954 955 956 957 958 959 960 961
	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;
	}
962 963 964

	spin_lock(&em_tree->lock);
	em = lookup_extent_mapping(em_tree, logical, *length);
965
	spin_unlock(&em_tree->lock);
966 967 968 969

	if (!em && unplug_page)
		return 0;

970 971
	if (!em) {
		printk("unable to find logical %Lu\n", logical);
972
		BUG();
973
	}
974 975 976 977

	BUG_ON(em->start > logical || em->start + em->len < logical);
	map = (struct map_lookup *)em->bdev;
	offset = logical - em->start;
978

979 980 981
	if (mirror_num > map->num_stripes)
		mirror_num = 0;

982
	/* if our multi bio struct is too small, back off and try again */
C
Chris Mason 已提交
983 984 985 986 987 988 989 990 991 992
	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) {
993 994 995 996 997
		stripes_allocated = map->num_stripes;
		free_extent_map(em);
		kfree(multi);
		goto again;
	}
998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010
	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;

1011
	if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
C
Chris Mason 已提交
1012
			 BTRFS_BLOCK_GROUP_RAID10 |
1013 1014 1015 1016 1017 1018 1019
			 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;
	}
1020 1021

	if (!multi_ret && !unplug_page)
1022 1023
		goto out;

1024
	num_stripes = 1;
1025
	stripe_index = 0;
1026
	if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1027 1028
		if (unplug_page || (rw & (1 << BIO_RW)))
			num_stripes = map->num_stripes;
1029 1030 1031
		else if (mirror_num) {
			stripe_index = mirror_num - 1;
		} else {
1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045
			int i;
			u64 least = (u64)-1;
			struct btrfs_device *cur;

			for (i = 0; i < map->num_stripes; i++) {
				cur = map->stripes[i].dev;
				spin_lock(&cur->io_lock);
				if (cur->total_ios < least) {
					least = cur->total_ios;
					stripe_index = i;
				}
				spin_unlock(&cur->io_lock);
			}
		}
1046
	} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1047
		if (rw & (1 << BIO_RW))
1048
			num_stripes = map->num_stripes;
1049 1050
		else if (mirror_num)
			stripe_index = mirror_num - 1;
C
Chris Mason 已提交
1051 1052 1053 1054 1055 1056 1057
	} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
		int factor = map->num_stripes / map->sub_stripes;
		int orig_stripe_nr = stripe_nr;

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

1058 1059
		if (unplug_page || (rw & (1 << BIO_RW)))
			num_stripes = map->sub_stripes;
C
Chris Mason 已提交
1060 1061 1062 1063
		else if (mirror_num)
			stripe_index += mirror_num - 1;
		else
			stripe_index += orig_stripe_nr % map->sub_stripes;
1064 1065 1066 1067 1068 1069 1070 1071
	} 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);
	}
1072
	BUG_ON(stripe_index >= map->num_stripes);
1073

1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089
	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;
		}
1090
		stripe_index++;
1091
	}
1092 1093 1094 1095
	if (multi_ret) {
		*multi_ret = multi;
		multi->num_stripes = num_stripes;
	}
1096
out:
1097 1098 1099 1100
	free_extent_map(em);
	return 0;
}

1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117
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);
}


1118 1119 1120 1121 1122 1123 1124
#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
{
1125
	struct btrfs_multi_bio *multi = bio->bi_private;
1126 1127 1128 1129 1130 1131 1132 1133

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

1134
	if (atomic_dec_and_test(&multi->stripes_pending)) {
1135 1136 1137 1138 1139 1140 1141
		bio->bi_private = multi->private;
		bio->bi_end_io = multi->end_io;

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

1142 1143 1144
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
		bio_endio(bio, bio->bi_size, err);
#else
1145
		bio_endio(bio, err);
1146
#endif
1147 1148 1149 1150 1151 1152 1153 1154
	} else {
		bio_put(bio);
	}
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
	return 0;
#endif
}

1155 1156
int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
		  int mirror_num)
1157 1158 1159
{
	struct btrfs_mapping_tree *map_tree;
	struct btrfs_device *dev;
1160
	struct bio *first_bio = bio;
1161 1162 1163
	u64 logical = bio->bi_sector << 9;
	u64 length = 0;
	u64 map_length;
1164
	struct btrfs_multi_bio *multi = NULL;
1165
	int ret;
1166 1167
	int dev_nr = 0;
	int total_devs = 1;
1168

1169
	length = bio->bi_size;
1170

1171 1172
	map_tree = &root->fs_info->mapping_tree;
	map_length = length;
1173

1174 1175
	ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
			      mirror_num);
1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187
	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);

1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198
	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;
		}
1199 1200
		bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
		dev = multi->stripes[dev_nr].dev;
1201 1202 1203 1204 1205 1206 1207
		bio->bi_bdev = dev->bdev;
		spin_lock(&dev->io_lock);
		dev->total_ios++;
		spin_unlock(&dev->io_lock);
		submit_bio(rw, bio);
		dev_nr++;
	}
1208 1209
	if (total_devs == 1)
		kfree(multi);
1210 1211 1212
	return 0;
}

1213 1214
struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
				       u8 *uuid)
1215
{
1216
	struct list_head *head = &root->fs_info->fs_devices->devices;
1217

1218
	return __find_device(head, devid, uuid);
1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230
}

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;
1231
	u8 uuid[BTRFS_UUID_SIZE];
1232
	int num_stripes;
1233
	int ret;
1234
	int i;
1235

1236 1237
	logical = key->offset;
	length = btrfs_chunk_length(leaf, chunk);
1238 1239
	spin_lock(&map_tree->map_tree.lock);
	em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
1240
	spin_unlock(&map_tree->map_tree.lock);
1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256

	/* 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;
1257 1258
	num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
	map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1259 1260 1261 1262 1263 1264 1265 1266 1267 1268
	if (!map) {
		free_extent_map(em);
		return -ENOMEM;
	}

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

1269 1270 1271 1272 1273 1274
	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
1275
	map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
1276 1277 1278 1279
	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);
1280 1281 1282 1283
		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);
1284 1285 1286 1287 1288
		if (!map->stripes[i].dev) {
			kfree(map);
			free_extent_map(em);
			return -EIO;
		}
1289 1290 1291 1292 1293
	}

	spin_lock(&map_tree->map_tree.lock);
	ret = add_extent_mapping(&map_tree->map_tree, em);
	spin_unlock(&map_tree->map_tree.lock);
1294
	BUG_ON(ret);
1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314
	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);
1315
	read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1316 1317 1318 1319

	return 0;
}

1320
static int read_one_dev(struct btrfs_root *root,
1321 1322 1323 1324 1325 1326
			struct extent_buffer *leaf,
			struct btrfs_dev_item *dev_item)
{
	struct btrfs_device *device;
	u64 devid;
	int ret;
1327 1328
	u8 dev_uuid[BTRFS_UUID_SIZE];

1329
	devid = btrfs_device_id(leaf, dev_item);
1330 1331 1332 1333
	read_extent_buffer(leaf, dev_uuid,
			   (unsigned long)btrfs_device_uuid(dev_item),
			   BTRFS_UUID_SIZE);
	device = btrfs_find_device(root, devid, dev_uuid);
1334
	if (!device) {
1335
		printk("warning devid %Lu not found already\n", devid);
1336
		device = kzalloc(sizeof(*device), GFP_NOFS);
1337 1338
		if (!device)
			return -ENOMEM;
1339 1340
		list_add(&device->dev_list,
			 &root->fs_info->fs_devices->devices);
1341
		device->barriers = 1;
1342
		spin_lock_init(&device->io_lock);
1343
	}
1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356

	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;
}

1357 1358 1359 1360 1361 1362 1363 1364 1365
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);
}

1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400
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;
	struct btrfs_key key;
	u32 num_stripes;
	u32 array_size;
	u32 len = 0;
	u8 *ptr;
	unsigned long sb_ptr;
	u32 cur;
	int ret;

	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;

1401
		if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1402
			chunk = (struct btrfs_chunk *)sb_ptr;
1403 1404
			ret = read_one_chunk(root, &key, sb, chunk);
			BUG_ON(ret);
1405 1406 1407 1408 1409 1410 1411 1412 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 1458 1459
			num_stripes = btrfs_chunk_num_stripes(sb, chunk);
			len = btrfs_chunk_item_size(num_stripes);
		} else {
			BUG();
		}
		ptr += len;
		sb_ptr += len;
		cur += len;
	}
	return 0;
}

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);
1460
				ret = read_one_dev(root, leaf, dev_item);
1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481
				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;
}