Logo Search packages:      
Sourcecode: partclone version File versions  Download package

volumes.c

/*
 * 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.
 */
#define _XOPEN_SOURCE 600
#define __USE_XOPEN2K
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <uuid/uuid.h>
#include <fcntl.h>
#include <unistd.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "print-tree.h"
#include "volumes.h"

00033 struct stripe {
      struct btrfs_device *dev;
      u64 physical;
};

00038 struct map_lookup {
      struct cache_extent ce;
      u64 type;
      int io_align;
      int io_width;
      int stripe_len;
      int sector_size;
      int num_stripes;
      int sub_stripes;
      struct btrfs_bio_stripe stripes[];
};

#define map_lookup_size(n) (sizeof(struct map_lookup) + \
                      (sizeof(struct btrfs_bio_stripe) * (n)))

static LIST_HEAD(fs_uuids);

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

      list_for_each(cur, head) {
            dev = list_entry(cur, struct btrfs_device, dev_list);
            if (dev->devid == devid &&
                !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE)) {
                  return dev;
            }
      }
      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 = kzalloc(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;
            device = NULL;
      } else {
            device = __find_device(&fs_devices->devices, devid,
                               disk_super->dev_item.uuid);
      }
      if (!device) {
            device = kzalloc(sizeof(*device), GFP_NOFS);
            if (!device) {
                  /* we can safely leave the fs_devices entry around */
                  return -ENOMEM;
            }
            device->devid = devid;
            memcpy(device->uuid, disk_super->dev_item.uuid,
                   BTRFS_UUID_SIZE);
            device->name = kstrdup(path, GFP_NOFS);
            if (!device->name) {
                  kfree(device);
                  return -ENOMEM;
            }
            device->label = kstrdup(disk_super->label, GFP_NOFS);
            device->total_devs = btrfs_super_num_devices(disk_super);
            device->super_bytes_used = btrfs_super_bytes_used(disk_super);
            device->total_bytes =
                  btrfs_stack_device_total_bytes(&disk_super->dev_item);
            device->bytes_used =
                  btrfs_stack_device_bytes_used(&disk_super->dev_item);
            list_add(&device->dev_list, &fs_devices->devices);
            device->fs_devices = fs_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 btrfs_fs_devices *seed_devices;
      struct list_head *cur;
      struct btrfs_device *device;
again:
      list_for_each(cur, &fs_devices->devices) {
            device = list_entry(cur, struct btrfs_device, dev_list);
            close(device->fd);
            device->fd = -1;
            device->writeable = 0;
      }

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

      return 0;
}

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

      list_for_each(cur, head) {
            device = list_entry(cur, struct btrfs_device, dev_list);

            fd = open(device->name, flags);
            if (fd < 0) {
                  ret = -errno;
                  goto fail;
            }

            if (device->devid == fs_devices->latest_devid)
                  fs_devices->latest_bdev = fd;
            if (device->devid == fs_devices->lowest_devid)
                  fs_devices->lowest_bdev = fd;
            device->fd = fd;
            if (flags == O_RDWR)
                  device->writeable = 1;
      }
      return 0;
fail:
      btrfs_close_devices(fs_devices);
      return ret;
}

int btrfs_scan_one_device(int fd, const char *path,
                    struct btrfs_fs_devices **fs_devices_ret,
                    u64 *total_devs, u64 super_offset)
{
      struct btrfs_super_block *disk_super;
      char *buf;
      int ret;
      u64 devid;
      char uuidbuf[37];

      buf = malloc(4096);
      if (!buf) {
            ret = -ENOMEM;
            goto error;
      }
      disk_super = (struct btrfs_super_block *)buf;
      ret = btrfs_read_dev_super(fd, disk_super, super_offset);
      if (ret < 0) {
            ret = -EIO;
            goto error_brelse;
      }
      devid = le64_to_cpu(disk_super->dev_item.devid);
      if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)
            *total_devs = 1;
      else
            *total_devs = btrfs_super_num_devices(disk_super);
      uuid_unparse(disk_super->fsid, uuidbuf);

      ret = device_list_add(path, disk_super, devid, fs_devices_ret);

error_brelse:
      free(buf);
error:
      return ret;
}

/*
 * 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 */

      /* 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);

      if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
            search_start = max(root->fs_info->alloc_start, search_start);

      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);

      if (*start + num_bytes > search_end) {
            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,
                     u64 chunk_tree, u64 chunk_objectid,
                     u64 chunk_offset,
                     u64 num_bytes, u64 *start)
{
      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);
      if (ret) {
            goto err;
      }

      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);
      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);

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

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

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

      key.objectid = objectid;
      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) {
            *offset = 0;
      } else {
            btrfs_item_key_to_cpu(path->nodes[0], &found_key,
                              path->slots[0]);
            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);
            }
      }
      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 = 0;

      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,
                              sizeof(*dev_item));
      if (ret)
            goto out;

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

      device->devid = free_devid;
      btrfs_set_device_id(leaf, dev_item, device->devid);
      btrfs_set_device_generation(leaf, dev_item, 0);
      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_set_device_group(leaf, dev_item, 0);
      btrfs_set_device_seek_speed(leaf, dev_item, 0);
      btrfs_set_device_bandwidth(leaf, dev_item, 0);
      btrfs_set_device_start_offset(leaf, dev_item, 0);

      ptr = (unsigned long)btrfs_device_uuid(dev_item);
      write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
      ptr = (unsigned long)btrfs_device_fsid(dev_item);
      write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
      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;
}

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

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;
}


int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                  struct btrfs_root *extent_root, u64 *start,
                  u64 *num_bytes, u64 type)
{
      u64 dev_offset;
      struct btrfs_fs_info *info = extent_root->fs_info;
      struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
      struct btrfs_stripe *stripes;
      struct btrfs_device *device = NULL;
      struct btrfs_chunk *chunk;
      struct list_head private_devs;
      struct list_head *dev_list = &extent_root->fs_info->fs_devices->devices;
      struct list_head *cur;
      struct map_lookup *map;
      int min_stripe_size = 1 * 1024 * 1024;
      u64 physical;
      u64 calc_size = 8 * 1024 * 1024;
      u64 min_free;
      u64 max_chunk_size = 4 * calc_size;
      u64 avail;
      u64 max_avail = 0;
      u64 percent_max;
      int num_stripes = 1;
      int min_stripes = 1;
      int sub_stripes = 0;
      int looped = 0;
      int ret;
      int index;
      int stripe_len = 64 * 1024;
      struct btrfs_key key;

      if (list_empty(dev_list)) {
            return -ENOSPC;
      }

      if (type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
                BTRFS_BLOCK_GROUP_RAID10 |
                BTRFS_BLOCK_GROUP_DUP)) {
            if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
                  calc_size = 8 * 1024 * 1024;
                  max_chunk_size = calc_size * 2;
                  min_stripe_size = 1 * 1024 * 1024;
            } else if (type & BTRFS_BLOCK_GROUP_DATA) {
                  calc_size = 1024 * 1024 * 1024;
                  max_chunk_size = 10 * calc_size;
                  min_stripe_size = 64 * 1024 * 1024;
            } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
                  calc_size = 1024 * 1024 * 1024;
                  max_chunk_size = 4 * calc_size;
                  min_stripe_size = 32 * 1024 * 1024;
            }
      }
      if (type & BTRFS_BLOCK_GROUP_RAID1) {
            num_stripes = min_t(u64, 2,
                          btrfs_super_num_devices(&info->super_copy));
            if (num_stripes < 2)
                  return -ENOSPC;
            min_stripes = 2;
      }
      if (type & BTRFS_BLOCK_GROUP_DUP) {
            num_stripes = 2;
            min_stripes = 2;
      }
      if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
            num_stripes = btrfs_super_num_devices(&info->super_copy);
            min_stripes = 2;
      }
      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;
            min_stripes = 4;
      }

      /* 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);

again:
      if (chunk_bytes_by_type(type, calc_size, num_stripes, sub_stripes) >
          max_chunk_size) {
            calc_size = max_chunk_size;
            calc_size /= num_stripes;
            calc_size /= stripe_len;
            calc_size *= stripe_len;
      }
      /* we don't want tiny stripes */
      calc_size = max_t(u64, calc_size, min_stripe_size);

      calc_size /= stripe_len;
      calc_size *= stripe_len;
      INIT_LIST_HEAD(&private_devs);
      cur = dev_list->next;
      index = 0;

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

      /* build a private list of devices we will allocate from */
      while(index < num_stripes) {
            device = list_entry(cur, struct btrfs_device, dev_list);
            avail = device->total_bytes - device->bytes_used;
            cur = cur->next;
            if (avail >= min_free) {
                  list_move_tail(&device->dev_list, &private_devs);
                  index++;
                  if (type & BTRFS_BLOCK_GROUP_DUP)
                        index++;
            } else if (avail > max_avail)
                  max_avail = avail;
            if (cur == dev_list)
                  break;
      }
      if (index < num_stripes) {
            list_splice(&private_devs, dev_list);
            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;
            }
            if (!looped && max_avail > 0) {
                  looped = 1;
                  calc_size = max_avail;
                  goto again;
            }
            return -ENOSPC;
      }
      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);
      if (ret)
            return ret;

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

      map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
      if (!map) {
            kfree(chunk);
            return -ENOMEM;
      }

      stripes = &chunk->stripe;
      *num_bytes = chunk_bytes_by_type(type, calc_size,
                               num_stripes, sub_stripes);
      index = 0;
      while(index < num_stripes) {
            struct btrfs_stripe *stripe;
            BUG_ON(list_empty(&private_devs));
            cur = private_devs.next;
            device = list_entry(cur, struct btrfs_device, dev_list);

            /* 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);

            ret = btrfs_alloc_dev_extent(trans, device,
                       info->chunk_root->root_key.objectid,
                       BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
                       calc_size, &dev_offset);
            BUG_ON(ret);

            device->bytes_used += calc_size;
            ret = btrfs_update_device(trans, device);
            BUG_ON(ret);

            map->stripes[index].dev = device;
            map->stripes[index].physical = dev_offset;
            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);
            physical = dev_offset;
            index++;
      }
      BUG_ON(!list_empty(&private_devs));

      /* key was set above */
      btrfs_set_stack_chunk_length(chunk, *num_bytes);
      btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
      btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
      btrfs_set_stack_chunk_type(chunk, type);
      btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
      btrfs_set_stack_chunk_io_align(chunk, stripe_len);
      btrfs_set_stack_chunk_io_width(chunk, stripe_len);
      btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
      btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
      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;
      map->sub_stripes = sub_stripes;

      ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
                        btrfs_chunk_item_size(num_stripes));
      BUG_ON(ret);
      *start = key.offset;;

      map->ce.start = key.offset;
      map->ce.size = *num_bytes;

      ret = insert_existing_cache_extent(
                     &extent_root->fs_info->mapping_tree.cache_tree,
                     &map->ce);
      BUG_ON(ret);

      if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
            ret = btrfs_add_system_chunk(trans, chunk_root, &key,
                            chunk, btrfs_chunk_item_size(num_stripes));
            BUG_ON(ret);
      }

      kfree(chunk);
      return ret;
}

void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
{
      cache_tree_init(&tree->cache_tree);
}

int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
{
      struct cache_extent *ce;
      struct map_lookup *map;
      int ret;
      u64 offset;

      ce = find_first_cache_extent(&map_tree->cache_tree, logical);
      BUG_ON(!ce);
      BUG_ON(ce->start > logical || ce->start + ce->size < logical);
      map = container_of(ce, struct map_lookup, ce);

      offset = logical - ce->start;
      if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
            ret = map->num_stripes;
      else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
            ret = map->sub_stripes;
      else
            ret = 1;
      return ret;
}

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 cache_extent *ce;
      struct map_lookup *map;
      u64 *buf;
      u64 bytenr;
      u64 length;
      u64 stripe_nr;
      int i, j, nr = 0;

      ce = find_first_cache_extent(&map_tree->cache_tree, chunk_start);
      BUG_ON(!ce);
      map = container_of(ce, struct map_lookup, ce);

      length = ce->size;
      if (map->type & BTRFS_BLOCK_GROUP_RAID10)
            length = ce->size / (map->num_stripes / map->sub_stripes);
      else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
            length = ce->size / map->num_stripes;

      buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);

      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) /
                      map->stripe_len;

            if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
                  stripe_nr = (stripe_nr * map->num_stripes + i) /
                            map->sub_stripes;
            } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
                  stripe_nr = stripe_nr * map->num_stripes + i;
            }
            bytenr = ce->start + stripe_nr * map->stripe_len;
            for (j = 0; j < nr; j++) {
                  if (buf[j] == bytenr)
                        break;
            }
            if (j == nr)
                  buf[nr++] = bytenr;
      }

      *logical = buf;
      *naddrs = nr;
      *stripe_len = map->stripe_len;

      return 0;
}

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 cache_extent *ce;
      struct map_lookup *map;
      u64 offset;
      u64 stripe_offset;
      u64 stripe_nr;
      int stripes_allocated = 8;
      int stripes_required = 1;
      int stripe_index;
      int i;
      struct btrfs_multi_bio *multi = NULL;

      if (multi_ret && rw == READ) {
            stripes_allocated = 1;
      }
again:
      if (multi_ret) {
            multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
                        GFP_NOFS);
            if (!multi)
                  return -ENOMEM;
      }

      ce = find_first_cache_extent(&map_tree->cache_tree, logical);
      BUG_ON(!ce);
      BUG_ON(ce->start > logical || ce->start + ce->size < logical);
      map = container_of(ce, struct map_lookup, ce);
      offset = logical - ce->start;

      if (rw == WRITE) {
            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 our multi bio struct is too small, back off and try again */
      if (multi_ret && rw == WRITE &&
          stripes_allocated < stripes_required) {
            stripes_allocated = map->num_stripes;
            kfree(multi);
            goto again;
      }
      stripe_nr = offset;
      /*
       * stripe_nr counts the total number of stripes we have to stride
       * to get to this block
       */
      stripe_nr = 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;

      if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
                   BTRFS_BLOCK_GROUP_RAID10 |
                   BTRFS_BLOCK_GROUP_DUP)) {
            /* we limit the length of each bio to what fits in a stripe */
            *length = min_t(u64, ce->size - offset,
                        map->stripe_len - stripe_offset);
      } else {
            *length = ce->size - offset;
      }

      if (!multi_ret)
            goto out;

      multi->num_stripes = 1;
      stripe_index = 0;
      if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
            if (rw == WRITE)
                  multi->num_stripes = map->num_stripes;
            else if (mirror_num)
                  stripe_index = mirror_num - 1;
            else
                  stripe_index = stripe_nr % map->num_stripes;
      } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
            int factor = map->num_stripes / map->sub_stripes;

            stripe_index = stripe_nr % factor;
            stripe_index *= map->sub_stripes;

            if (rw == WRITE)
                  multi->num_stripes = map->sub_stripes;
            else if (mirror_num)
                  stripe_index += mirror_num - 1;
            else
                  stripe_index = stripe_nr % map->sub_stripes;

            stripe_nr = stripe_nr / factor;
      } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
            if (rw == WRITE)
                  multi->num_stripes = map->num_stripes;
            else if (mirror_num)
                  stripe_index = mirror_num - 1;
      } 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 = stripe_nr % map->num_stripes;
            stripe_nr = stripe_nr / map->num_stripes;
      }
      BUG_ON(stripe_index >= map->num_stripes);

      for (i = 0; i < multi->num_stripes; i++) {
            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;
            stripe_index++;
      }
      *multi_ret = multi;
out:
      return 0;
}

struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
                               u8 *uuid, u8 *fsid)
{
      struct btrfs_device *device;
      struct btrfs_fs_devices *cur_devices;

      cur_devices = root->fs_info->fs_devices;
      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;
}

int btrfs_bootstrap_super_map(struct btrfs_mapping_tree *map_tree,
                        struct btrfs_fs_devices *fs_devices)
{
      struct map_lookup *map;
      u64 logical = BTRFS_SUPER_INFO_OFFSET;
      u64 length = BTRFS_SUPER_INFO_SIZE;
      int num_stripes = 0;
      int sub_stripes = 0;
      int ret;
      int i;
      struct list_head *cur;

      list_for_each(cur, &fs_devices->devices) {
            num_stripes++;
      }
      map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
      if (!map)
            return -ENOMEM;

      map->ce.start = logical;
      map->ce.size = length;
      map->num_stripes = num_stripes;
      map->sub_stripes = sub_stripes;
      map->io_width = length;
      map->io_align = length;
      map->sector_size = length;
      map->stripe_len = length;
      map->type = BTRFS_BLOCK_GROUP_RAID1;

      i = 0;
      list_for_each(cur, &fs_devices->devices) {
            struct btrfs_device *device = list_entry(cur,
                                           struct btrfs_device,
                                           dev_list);
            map->stripes[i].physical = logical;
            map->stripes[i].dev = device;
            i++;
      }
      ret = insert_existing_cache_extent(&map_tree->cache_tree, &map->ce);
      if (ret == -EEXIST) {
            struct cache_extent *old;
            struct map_lookup *old_map;
            old = find_cache_extent(&map_tree->cache_tree, logical, length);
            old_map = container_of(old, struct map_lookup, ce);
            remove_cache_extent(&map_tree->cache_tree, old);
            kfree(old_map);
            ret = insert_existing_cache_extent(&map_tree->cache_tree,
                                       &map->ce);
      }
      BUG_ON(ret);
      return 0;
}

int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
{
      struct cache_extent *ce;
      struct map_lookup *map;
      struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
      int readonly = 0;
      int i;

      ce = find_first_cache_extent(&map_tree->cache_tree, chunk_offset);
      BUG_ON(!ce);

      map = container_of(ce, struct map_lookup, ce);
      for (i = 0; i < map->num_stripes; i++) {
            if (!map->stripes[i].dev->writeable) {
                  readonly = 1;
                  break;
            }
      }

      return readonly;
}

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 cache_extent *ce;
      u64 logical;
      u64 length;
      u64 devid;
      u8 uuid[BTRFS_UUID_SIZE];
      int num_stripes;
      int ret;
      int i;

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

      ce = find_first_cache_extent(&map_tree->cache_tree, logical);

      /* already mapped? */
      if (ce && ce->start <= logical && ce->start + ce->size > logical) {
            return 0;
      }

      num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
      map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
      if (!map)
            return -ENOMEM;

      map->ce.start = logical;
      map->ce.size = length;
      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);
      map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);

      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);
            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,
                                          NULL);
            if (!map->stripes[i].dev) {
                  kfree(map);
                  return -EIO;
            }

      }
      ret = insert_existing_cache_extent(&map_tree->cache_tree, &map->ce);
      BUG_ON(ret);

      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);
      read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);

      return 0;
}

static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
{
      struct btrfs_fs_devices *fs_devices;
      int ret;

      fs_devices = root->fs_info->fs_devices->seed;
      while (fs_devices) {
            if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
                  ret = 0;
                  goto out;
            }
            fs_devices = fs_devices->seed;
      }

      fs_devices = find_fsid(fsid);
      if (!fs_devices) {
            ret = -ENOENT;
            goto out;
      }

      ret = btrfs_open_devices(fs_devices, O_RDONLY);
      if (ret)
            goto out;

      fs_devices->seed = root->fs_info->fs_devices->seed;
      root->fs_info->fs_devices->seed = fs_devices;
out:
      return ret;
}

static int read_one_dev(struct btrfs_root *root,
                  struct extent_buffer *leaf,
                  struct btrfs_dev_item *dev_item)
{
      struct btrfs_device *device;
      u64 devid;
      int ret = 0;
      u8 fs_uuid[BTRFS_UUID_SIZE];
      u8 dev_uuid[BTRFS_UUID_SIZE];

      devid = btrfs_device_id(leaf, dev_item);
      read_extent_buffer(leaf, dev_uuid,
                     (unsigned long)btrfs_device_uuid(dev_item),
                     BTRFS_UUID_SIZE);
      read_extent_buffer(leaf, fs_uuid,
                     (unsigned long)btrfs_device_fsid(dev_item),
                     BTRFS_UUID_SIZE);

      if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
            ret = open_seed_devices(root, fs_uuid);
            if (ret)
                  return ret;
      }

      device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
      if (!device) {
            printk("warning devid %llu not found already\n",
                  (unsigned long long)devid);
            device = kmalloc(sizeof(*device), GFP_NOFS);
            if (!device)
                  return -ENOMEM;
            device->total_ios = 0;
            list_add(&device->dev_list,
                   &root->fs_info->fs_devices->devices);
      }

      fill_device_from_item(leaf, dev_item, device);
      device->dev_root = root->fs_info->dev_root;
      return ret;
}

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);
}

int btrfs_read_sys_array(struct btrfs_root *root)
{
      struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
      struct extent_buffer *sb;
      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;

      sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
                                BTRFS_SUPER_INFO_SIZE);
      if (!sb)
            return -ENOMEM;
      btrfs_set_buffer_uptodate(sb);
      write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
      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;

            if (key.type == BTRFS_CHUNK_ITEM_KEY) {
                  chunk = (struct btrfs_chunk *)sb_ptr;
                  ret = read_one_chunk(root, &key, sb, chunk);
                  BUG_ON(ret);
                  num_stripes = btrfs_chunk_num_stripes(sb, chunk);
                  len = btrfs_chunk_item_size(num_stripes);
            } else {
                  BUG();
            }
            ptr += len;
            sb_ptr += len;
            cur += len;
      }
      free_extent_buffer(sb);
      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);
                        ret = read_one_dev(root, leaf, dev_item);
                        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);
                  BUG_ON(ret);
            }
            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;
}

struct list_head *btrfs_scanned_uuids(void)
{
      return &fs_uuids;
}

Generated by  Doxygen 1.6.0   Back to index