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* Copyright (C) 2007 Oracle. All rights reserved.
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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#define _XOPEN_SOURCE 600
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#include <sys/types.h>
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#include <uuid/uuid.h>
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#include "transaction.h"
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#include "print-tree.h"
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struct btrfs_device *dev;
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static inline int nr_parity_stripes(struct map_lookup *map)
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if (map->type & BTRFS_BLOCK_GROUP_RAID5)
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else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
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static inline int nr_data_stripes(struct map_lookup *map)
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return map->num_stripes - nr_parity_stripes(map);
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#define is_parity_stripe(x) ( ((x) == BTRFS_RAID5_P_STRIPE) || ((x) == BTRFS_RAID6_Q_STRIPE) )
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static LIST_HEAD(fs_uuids);
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static struct btrfs_device *__find_device(struct list_head *head, u64 devid,
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struct btrfs_device *dev;
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struct list_head *cur;
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list_for_each(cur, head) {
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dev = list_entry(cur, struct btrfs_device, dev_list);
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if (dev->devid == devid &&
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!memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE)) {
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static struct btrfs_fs_devices *find_fsid(u8 *fsid)
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struct list_head *cur;
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struct btrfs_fs_devices *fs_devices;
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list_for_each(cur, &fs_uuids) {
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fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
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if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
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static int device_list_add(const char *path,
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struct btrfs_super_block *disk_super,
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u64 devid, struct btrfs_fs_devices **fs_devices_ret)
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struct btrfs_device *device;
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struct btrfs_fs_devices *fs_devices;
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u64 found_transid = btrfs_super_generation(disk_super);
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fs_devices = find_fsid(disk_super->fsid);
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fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
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INIT_LIST_HEAD(&fs_devices->devices);
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list_add(&fs_devices->list, &fs_uuids);
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memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
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fs_devices->latest_devid = devid;
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fs_devices->latest_trans = found_transid;
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fs_devices->lowest_devid = (u64)-1;
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device = __find_device(&fs_devices->devices, devid,
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disk_super->dev_item.uuid);
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device = kzalloc(sizeof(*device), GFP_NOFS);
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/* we can safely leave the fs_devices entry around */
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device->devid = devid;
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memcpy(device->uuid, disk_super->dev_item.uuid,
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device->name = kstrdup(path, GFP_NOFS);
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device->label = kstrdup(disk_super->label, GFP_NOFS);
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if (!device->label) {
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device->total_devs = btrfs_super_num_devices(disk_super);
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device->super_bytes_used = btrfs_super_bytes_used(disk_super);
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device->total_bytes =
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btrfs_stack_device_total_bytes(&disk_super->dev_item);
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btrfs_stack_device_bytes_used(&disk_super->dev_item);
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list_add(&device->dev_list, &fs_devices->devices);
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device->fs_devices = fs_devices;
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} else if (!device->name || strcmp(device->name, path)) {
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char *name = strdup(path);
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if (found_transid > fs_devices->latest_trans) {
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fs_devices->latest_devid = devid;
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fs_devices->latest_trans = found_transid;
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if (fs_devices->lowest_devid > devid) {
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fs_devices->lowest_devid = devid;
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*fs_devices_ret = fs_devices;
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int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
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struct btrfs_fs_devices *seed_devices;
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struct btrfs_device *device;
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while (!list_empty(&fs_devices->devices)) {
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device = list_entry(fs_devices->devices.next,
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struct btrfs_device, dev_list);
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if (device->fd != -1) {
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if (posix_fadvise(device->fd, 0, 0, POSIX_FADV_DONTNEED))
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fprintf(stderr, "Warning, could not drop caches\n");
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device->writeable = 0;
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list_del(&device->dev_list);
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/* free the memory */
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seed_devices = fs_devices->seed;
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fs_devices->seed = NULL;
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fs_devices = seed_devices;
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int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, int flags)
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struct list_head *head = &fs_devices->devices;
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struct list_head *cur;
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struct btrfs_device *device;
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list_for_each(cur, head) {
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device = list_entry(cur, struct btrfs_device, dev_list);
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printk("no name for device %llu, skip it now\n", device->devid);
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fd = open(device->name, flags);
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if (posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED))
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fprintf(stderr, "Warning, could not drop caches\n");
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if (device->devid == fs_devices->latest_devid)
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fs_devices->latest_bdev = fd;
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if (device->devid == fs_devices->lowest_devid)
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fs_devices->lowest_bdev = fd;
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device->writeable = 1;
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btrfs_close_devices(fs_devices);
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int btrfs_scan_one_device(int fd, const char *path,
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struct btrfs_fs_devices **fs_devices_ret,
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u64 *total_devs, u64 super_offset)
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struct btrfs_super_block *disk_super;
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disk_super = (struct btrfs_super_block *)buf;
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ret = btrfs_read_dev_super(fd, disk_super, super_offset);
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devid = btrfs_stack_device_id(&disk_super->dev_item);
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if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)
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*total_devs = btrfs_super_num_devices(disk_super);
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ret = device_list_add(path, disk_super, devid, fs_devices_ret);
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* this uses a pretty simple search, the expectation is that it is
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* called very infrequently and that a given device has a small number
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static int find_free_dev_extent(struct btrfs_trans_handle *trans,
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struct btrfs_device *device,
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struct btrfs_path *path,
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u64 num_bytes, u64 *start)
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struct btrfs_key key;
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struct btrfs_root *root = device->dev_root;
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struct btrfs_dev_extent *dev_extent = NULL;
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u64 search_start = root->fs_info->alloc_start;
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u64 search_end = device->total_bytes;
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struct extent_buffer *l;
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/* FIXME use last free of some kind */
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/* we don't want to overwrite the superblock on the drive,
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* so we make sure to start at an offset of at least 1MB
297
search_start = max(BTRFS_BLOCK_RESERVED_1M_FOR_SUPER, search_start);
299
if (search_start >= search_end) {
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key.objectid = device->devid;
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key.offset = search_start;
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key.type = BTRFS_DEV_EXTENT_KEY;
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ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
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ret = btrfs_previous_item(root, path, 0, key.type);
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btrfs_item_key_to_cpu(l, &key, path->slots[0]);
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slot = path->slots[0];
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if (slot >= btrfs_header_nritems(l)) {
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ret = btrfs_next_leaf(root, path);
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if (search_start >= search_end) {
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*start = search_start;
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*start = last_byte > search_start ?
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last_byte : search_start;
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if (search_end <= *start) {
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btrfs_item_key_to_cpu(l, &key, slot);
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if (key.objectid < device->devid)
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if (key.objectid > device->devid)
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if (key.offset >= search_start && key.offset > last_byte &&
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if (last_byte < search_start)
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last_byte = search_start;
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hole_size = key.offset - last_byte;
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if (key.offset > last_byte &&
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hole_size >= num_bytes) {
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if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
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dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
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last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
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/* we have to make sure we didn't find an extent that has already
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* been allocated by the map tree or the original allocation
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btrfs_release_path(path);
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BUG_ON(*start < search_start);
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if (*start + num_bytes > search_end) {
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/* check for pending inserts here */
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btrfs_release_path(path);
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static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
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struct btrfs_device *device,
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u64 chunk_tree, u64 chunk_objectid,
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u64 num_bytes, u64 *start)
398
struct btrfs_path *path;
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struct btrfs_root *root = device->dev_root;
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struct btrfs_dev_extent *extent;
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struct extent_buffer *leaf;
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struct btrfs_key key;
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path = btrfs_alloc_path();
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ret = find_free_dev_extent(trans, device, path, num_bytes, start);
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key.objectid = device->devid;
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key.type = BTRFS_DEV_EXTENT_KEY;
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ret = btrfs_insert_empty_item(trans, root, path, &key,
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leaf = path->nodes[0];
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extent = btrfs_item_ptr(leaf, path->slots[0],
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struct btrfs_dev_extent);
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btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
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btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
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btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
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write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
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(unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
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btrfs_set_dev_extent_length(leaf, extent, num_bytes);
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btrfs_mark_buffer_dirty(leaf);
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btrfs_free_path(path);
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static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset)
440
struct btrfs_path *path;
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struct btrfs_key key;
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struct btrfs_chunk *chunk;
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struct btrfs_key found_key;
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path = btrfs_alloc_path();
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key.objectid = objectid;
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key.offset = (u64)-1;
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key.type = BTRFS_CHUNK_ITEM_KEY;
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ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
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ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
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btrfs_item_key_to_cpu(path->nodes[0], &found_key,
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if (found_key.objectid != objectid)
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chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
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*offset = found_key.offset +
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btrfs_chunk_length(path->nodes[0], chunk);
476
btrfs_free_path(path);
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static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
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struct btrfs_key key;
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struct btrfs_key found_key;
487
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
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key.type = BTRFS_DEV_ITEM_KEY;
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key.offset = (u64)-1;
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ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
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ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
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btrfs_item_key_to_cpu(path->nodes[0], &found_key,
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*objectid = found_key.offset + 1;
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btrfs_release_path(path);
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* the device information is stored in the chunk root
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* the btrfs_device struct should be fully filled in
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int btrfs_add_device(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct btrfs_device *device)
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struct btrfs_path *path;
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struct btrfs_dev_item *dev_item;
523
struct extent_buffer *leaf;
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struct btrfs_key key;
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root = root->fs_info->chunk_root;
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path = btrfs_alloc_path();
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ret = find_next_devid(root, path, &free_devid);
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key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
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key.type = BTRFS_DEV_ITEM_KEY;
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key.offset = free_devid;
542
ret = btrfs_insert_empty_item(trans, root, path, &key,
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leaf = path->nodes[0];
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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);
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btrfs_set_device_generation(leaf, dev_item, 0);
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btrfs_set_device_type(leaf, dev_item, device->type);
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btrfs_set_device_io_align(leaf, dev_item, device->io_align);
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btrfs_set_device_io_width(leaf, dev_item, device->io_width);
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btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
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btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
558
btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
559
btrfs_set_device_group(leaf, dev_item, 0);
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btrfs_set_device_seek_speed(leaf, dev_item, 0);
561
btrfs_set_device_bandwidth(leaf, dev_item, 0);
562
btrfs_set_device_start_offset(leaf, dev_item, 0);
564
ptr = (unsigned long)btrfs_device_uuid(dev_item);
565
write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
566
ptr = (unsigned long)btrfs_device_fsid(dev_item);
567
write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
568
btrfs_mark_buffer_dirty(leaf);
572
btrfs_free_path(path);
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int btrfs_update_device(struct btrfs_trans_handle *trans,
577
struct btrfs_device *device)
580
struct btrfs_path *path;
581
struct btrfs_root *root;
582
struct btrfs_dev_item *dev_item;
583
struct extent_buffer *leaf;
584
struct btrfs_key key;
586
root = device->dev_root->fs_info->chunk_root;
588
path = btrfs_alloc_path();
592
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
593
key.type = BTRFS_DEV_ITEM_KEY;
594
key.offset = device->devid;
596
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
605
leaf = path->nodes[0];
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dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
608
btrfs_set_device_id(leaf, dev_item, device->devid);
609
btrfs_set_device_type(leaf, dev_item, device->type);
610
btrfs_set_device_io_align(leaf, dev_item, device->io_align);
611
btrfs_set_device_io_width(leaf, dev_item, device->io_width);
612
btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
613
btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
614
btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
615
btrfs_mark_buffer_dirty(leaf);
618
btrfs_free_path(path);
622
int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
623
struct btrfs_root *root,
624
struct btrfs_key *key,
625
struct btrfs_chunk *chunk, int item_size)
627
struct btrfs_super_block *super_copy = root->fs_info->super_copy;
628
struct btrfs_disk_key disk_key;
632
array_size = btrfs_super_sys_array_size(super_copy);
633
if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
636
ptr = super_copy->sys_chunk_array + array_size;
637
btrfs_cpu_key_to_disk(&disk_key, key);
638
memcpy(ptr, &disk_key, sizeof(disk_key));
639
ptr += sizeof(disk_key);
640
memcpy(ptr, chunk, item_size);
641
item_size += sizeof(disk_key);
642
btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
646
static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
649
if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
651
else if (type & BTRFS_BLOCK_GROUP_RAID10)
652
return calc_size * (num_stripes / sub_stripes);
653
else if (type & BTRFS_BLOCK_GROUP_RAID5)
654
return calc_size * (num_stripes - 1);
655
else if (type & BTRFS_BLOCK_GROUP_RAID6)
656
return calc_size * (num_stripes - 2);
658
return calc_size * num_stripes;
662
static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
664
/* TODO, add a way to store the preferred stripe size */
665
return BTRFS_STRIPE_LEN;
669
* btrfs_device_avail_bytes - count bytes available for alloc_chunk
671
* It is not equal to "device->total_bytes - device->bytes_used".
672
* We do not allocate any chunk in 1M at beginning of device, and not
673
* allowed to allocate any chunk before alloc_start if it is specified.
674
* So search holes from max(1M, alloc_start) to device->total_bytes.
676
static int btrfs_device_avail_bytes(struct btrfs_trans_handle *trans,
677
struct btrfs_device *device,
680
struct btrfs_path *path;
681
struct btrfs_root *root = device->dev_root;
682
struct btrfs_key key;
683
struct btrfs_dev_extent *dev_extent = NULL;
684
struct extent_buffer *l;
685
u64 search_start = root->fs_info->alloc_start;
686
u64 search_end = device->total_bytes;
692
search_start = max(BTRFS_BLOCK_RESERVED_1M_FOR_SUPER, search_start);
694
path = btrfs_alloc_path();
698
key.objectid = device->devid;
699
key.offset = root->fs_info->alloc_start;
700
key.type = BTRFS_DEV_EXTENT_KEY;
703
ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
706
ret = btrfs_previous_item(root, path, 0, key.type);
712
slot = path->slots[0];
713
if (slot >= btrfs_header_nritems(l)) {
714
ret = btrfs_next_leaf(root, path);
721
btrfs_item_key_to_cpu(l, &key, slot);
723
if (key.objectid < device->devid)
725
if (key.objectid > device->devid)
727
if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
729
if (key.offset > search_end)
731
if (key.offset > search_start)
732
free_bytes += key.offset - search_start;
734
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
735
extent_end = key.offset + btrfs_dev_extent_length(l,
737
if (extent_end > search_start)
738
search_start = extent_end;
739
if (search_start > search_end)
746
if (search_start < search_end)
747
free_bytes += search_end - search_start;
749
*avail_bytes = free_bytes;
752
btrfs_free_path(path);
756
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
757
struct btrfs_root *extent_root, u64 *start,
758
u64 *num_bytes, u64 type)
761
struct btrfs_fs_info *info = extent_root->fs_info;
762
struct btrfs_root *chunk_root = info->chunk_root;
763
struct btrfs_stripe *stripes;
764
struct btrfs_device *device = NULL;
765
struct btrfs_chunk *chunk;
766
struct list_head private_devs;
767
struct list_head *dev_list = &info->fs_devices->devices;
768
struct list_head *cur;
769
struct map_lookup *map;
770
int min_stripe_size = 1 * 1024 * 1024;
771
u64 calc_size = 8 * 1024 * 1024;
773
u64 max_chunk_size = 4 * calc_size;
783
int stripe_len = BTRFS_STRIPE_LEN;
784
struct btrfs_key key;
787
if (list_empty(dev_list)) {
791
if (type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
792
BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
793
BTRFS_BLOCK_GROUP_RAID10 |
794
BTRFS_BLOCK_GROUP_DUP)) {
795
if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
796
calc_size = 8 * 1024 * 1024;
797
max_chunk_size = calc_size * 2;
798
min_stripe_size = 1 * 1024 * 1024;
799
} else if (type & BTRFS_BLOCK_GROUP_DATA) {
800
calc_size = 1024 * 1024 * 1024;
801
max_chunk_size = 10 * calc_size;
802
min_stripe_size = 64 * 1024 * 1024;
803
} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
804
calc_size = 1024 * 1024 * 1024;
805
max_chunk_size = 4 * calc_size;
806
min_stripe_size = 32 * 1024 * 1024;
809
if (type & BTRFS_BLOCK_GROUP_RAID1) {
810
num_stripes = min_t(u64, 2,
811
btrfs_super_num_devices(info->super_copy));
816
if (type & BTRFS_BLOCK_GROUP_DUP) {
820
if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
821
num_stripes = btrfs_super_num_devices(info->super_copy);
824
if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
825
num_stripes = btrfs_super_num_devices(info->super_copy);
828
num_stripes &= ~(u32)1;
832
if (type & (BTRFS_BLOCK_GROUP_RAID5)) {
833
num_stripes = btrfs_super_num_devices(info->super_copy);
837
stripe_len = find_raid56_stripe_len(num_stripes - 1,
838
btrfs_super_stripesize(info->super_copy));
840
if (type & (BTRFS_BLOCK_GROUP_RAID6)) {
841
num_stripes = btrfs_super_num_devices(info->super_copy);
845
stripe_len = find_raid56_stripe_len(num_stripes - 2,
846
btrfs_super_stripesize(info->super_copy));
849
/* we don't want a chunk larger than 10% of the FS */
850
percent_max = div_factor(btrfs_super_total_bytes(info->super_copy), 1);
851
max_chunk_size = min(percent_max, max_chunk_size);
854
if (chunk_bytes_by_type(type, calc_size, num_stripes, sub_stripes) >
856
calc_size = max_chunk_size;
857
calc_size /= num_stripes;
858
calc_size /= stripe_len;
859
calc_size *= stripe_len;
861
/* we don't want tiny stripes */
862
calc_size = max_t(u64, calc_size, min_stripe_size);
864
calc_size /= stripe_len;
865
calc_size *= stripe_len;
866
INIT_LIST_HEAD(&private_devs);
867
cur = dev_list->next;
870
if (type & BTRFS_BLOCK_GROUP_DUP)
871
min_free = calc_size * 2;
873
min_free = calc_size;
875
/* build a private list of devices we will allocate from */
876
while(index < num_stripes) {
877
device = list_entry(cur, struct btrfs_device, dev_list);
878
ret = btrfs_device_avail_bytes(trans, device, &avail);
882
if (avail >= min_free) {
883
list_move_tail(&device->dev_list, &private_devs);
885
if (type & BTRFS_BLOCK_GROUP_DUP)
887
} else if (avail > max_avail)
892
if (index < num_stripes) {
893
list_splice(&private_devs, dev_list);
894
if (index >= min_stripes) {
896
if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
897
num_stripes /= sub_stripes;
898
num_stripes *= sub_stripes;
903
if (!looped && max_avail > 0) {
905
calc_size = max_avail;
910
ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
914
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
915
key.type = BTRFS_CHUNK_ITEM_KEY;
918
chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
922
map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
928
stripes = &chunk->stripe;
929
*num_bytes = chunk_bytes_by_type(type, calc_size,
930
num_stripes, sub_stripes);
932
while(index < num_stripes) {
933
struct btrfs_stripe *stripe;
934
BUG_ON(list_empty(&private_devs));
935
cur = private_devs.next;
936
device = list_entry(cur, struct btrfs_device, dev_list);
938
/* loop over this device again if we're doing a dup group */
939
if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
940
(index == num_stripes - 1))
941
list_move_tail(&device->dev_list, dev_list);
943
ret = btrfs_alloc_dev_extent(trans, device,
944
info->chunk_root->root_key.objectid,
945
BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
946
calc_size, &dev_offset);
949
device->bytes_used += calc_size;
950
ret = btrfs_update_device(trans, device);
953
map->stripes[index].dev = device;
954
map->stripes[index].physical = dev_offset;
955
stripe = stripes + index;
956
btrfs_set_stack_stripe_devid(stripe, device->devid);
957
btrfs_set_stack_stripe_offset(stripe, dev_offset);
958
memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
961
BUG_ON(!list_empty(&private_devs));
963
/* key was set above */
964
btrfs_set_stack_chunk_length(chunk, *num_bytes);
965
btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
966
btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
967
btrfs_set_stack_chunk_type(chunk, type);
968
btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
969
btrfs_set_stack_chunk_io_align(chunk, stripe_len);
970
btrfs_set_stack_chunk_io_width(chunk, stripe_len);
971
btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
972
btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
973
map->sector_size = extent_root->sectorsize;
974
map->stripe_len = stripe_len;
975
map->io_align = stripe_len;
976
map->io_width = stripe_len;
978
map->num_stripes = num_stripes;
979
map->sub_stripes = sub_stripes;
981
ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
982
btrfs_chunk_item_size(num_stripes));
984
*start = key.offset;;
986
map->ce.start = key.offset;
987
map->ce.size = *num_bytes;
989
ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
992
if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
993
ret = btrfs_add_system_chunk(trans, chunk_root, &key,
994
chunk, btrfs_chunk_item_size(num_stripes));
1002
int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
1003
struct btrfs_root *extent_root, u64 *start,
1004
u64 num_bytes, u64 type)
1007
struct btrfs_fs_info *info = extent_root->fs_info;
1008
struct btrfs_root *chunk_root = info->chunk_root;
1009
struct btrfs_stripe *stripes;
1010
struct btrfs_device *device = NULL;
1011
struct btrfs_chunk *chunk;
1012
struct list_head *dev_list = &info->fs_devices->devices;
1013
struct list_head *cur;
1014
struct map_lookup *map;
1015
u64 calc_size = 8 * 1024 * 1024;
1016
int num_stripes = 1;
1017
int sub_stripes = 0;
1020
int stripe_len = BTRFS_STRIPE_LEN;
1021
struct btrfs_key key;
1023
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1024
key.type = BTRFS_CHUNK_ITEM_KEY;
1025
ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
1030
chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
1034
map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
1040
stripes = &chunk->stripe;
1041
calc_size = num_bytes;
1044
cur = dev_list->next;
1045
device = list_entry(cur, struct btrfs_device, dev_list);
1047
while (index < num_stripes) {
1048
struct btrfs_stripe *stripe;
1050
ret = btrfs_alloc_dev_extent(trans, device,
1051
info->chunk_root->root_key.objectid,
1052
BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
1053
calc_size, &dev_offset);
1056
device->bytes_used += calc_size;
1057
ret = btrfs_update_device(trans, device);
1060
map->stripes[index].dev = device;
1061
map->stripes[index].physical = dev_offset;
1062
stripe = stripes + index;
1063
btrfs_set_stack_stripe_devid(stripe, device->devid);
1064
btrfs_set_stack_stripe_offset(stripe, dev_offset);
1065
memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
1069
/* key was set above */
1070
btrfs_set_stack_chunk_length(chunk, num_bytes);
1071
btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
1072
btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
1073
btrfs_set_stack_chunk_type(chunk, type);
1074
btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
1075
btrfs_set_stack_chunk_io_align(chunk, stripe_len);
1076
btrfs_set_stack_chunk_io_width(chunk, stripe_len);
1077
btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
1078
btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
1079
map->sector_size = extent_root->sectorsize;
1080
map->stripe_len = stripe_len;
1081
map->io_align = stripe_len;
1082
map->io_width = stripe_len;
1084
map->num_stripes = num_stripes;
1085
map->sub_stripes = sub_stripes;
1087
ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
1088
btrfs_chunk_item_size(num_stripes));
1090
*start = key.offset;
1092
map->ce.start = key.offset;
1093
map->ce.size = num_bytes;
1095
ret = insert_cache_extent(&info->mapping_tree.cache_tree, &map->ce);
1102
int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
1104
struct cache_extent *ce;
1105
struct map_lookup *map;
1108
ce = search_cache_extent(&map_tree->cache_tree, logical);
1110
BUG_ON(ce->start > logical || ce->start + ce->size < logical);
1111
map = container_of(ce, struct map_lookup, ce);
1113
if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
1114
ret = map->num_stripes;
1115
else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
1116
ret = map->sub_stripes;
1117
else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
1119
else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
1126
int btrfs_next_metadata(struct btrfs_mapping_tree *map_tree, u64 *logical,
1129
struct cache_extent *ce;
1130
struct map_lookup *map;
1132
ce = search_cache_extent(&map_tree->cache_tree, *logical);
1135
ce = next_cache_extent(ce);
1139
map = container_of(ce, struct map_lookup, ce);
1140
if (map->type & BTRFS_BLOCK_GROUP_METADATA) {
1141
*logical = ce->start;
1150
int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
1151
u64 chunk_start, u64 physical, u64 devid,
1152
u64 **logical, int *naddrs, int *stripe_len)
1154
struct cache_extent *ce;
1155
struct map_lookup *map;
1163
ce = search_cache_extent(&map_tree->cache_tree, chunk_start);
1165
map = container_of(ce, struct map_lookup, ce);
1168
rmap_len = map->stripe_len;
1169
if (map->type & BTRFS_BLOCK_GROUP_RAID10)
1170
length = ce->size / (map->num_stripes / map->sub_stripes);
1171
else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
1172
length = ce->size / map->num_stripes;
1173
else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
1174
BTRFS_BLOCK_GROUP_RAID6)) {
1175
length = ce->size / nr_data_stripes(map);
1176
rmap_len = map->stripe_len * nr_data_stripes(map);
1179
buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
1181
for (i = 0; i < map->num_stripes; i++) {
1182
if (devid && map->stripes[i].dev->devid != devid)
1184
if (map->stripes[i].physical > physical ||
1185
map->stripes[i].physical + length <= physical)
1188
stripe_nr = (physical - map->stripes[i].physical) /
1191
if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1192
stripe_nr = (stripe_nr * map->num_stripes + i) /
1194
} else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
1195
stripe_nr = stripe_nr * map->num_stripes + i;
1196
} /* else if RAID[56], multiply by nr_data_stripes().
1197
* Alternatively, just use rmap_len below instead of
1198
* map->stripe_len */
1200
bytenr = ce->start + stripe_nr * rmap_len;
1201
for (j = 0; j < nr; j++) {
1202
if (buf[j] == bytenr)
1211
*stripe_len = rmap_len;
1216
static inline int parity_smaller(u64 a, u64 b)
1221
/* Bubble-sort the stripe set to put the parity/syndrome stripes last */
1222
static void sort_parity_stripes(struct btrfs_multi_bio *bbio, u64 *raid_map)
1224
struct btrfs_bio_stripe s;
1231
for (i = 0; i < bbio->num_stripes - 1; i++) {
1232
if (parity_smaller(raid_map[i], raid_map[i+1])) {
1233
s = bbio->stripes[i];
1235
bbio->stripes[i] = bbio->stripes[i+1];
1236
raid_map[i] = raid_map[i+1];
1237
bbio->stripes[i+1] = s;
1245
int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1246
u64 logical, u64 *length,
1247
struct btrfs_multi_bio **multi_ret, int mirror_num,
1250
return __btrfs_map_block(map_tree, rw, logical, length, NULL,
1251
multi_ret, mirror_num, raid_map_ret);
1254
int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1255
u64 logical, u64 *length, u64 *type,
1256
struct btrfs_multi_bio **multi_ret, int mirror_num,
1259
struct cache_extent *ce;
1260
struct map_lookup *map;
1264
u64 *raid_map = NULL;
1265
int stripes_allocated = 8;
1266
int stripes_required = 1;
1269
struct btrfs_multi_bio *multi = NULL;
1271
if (multi_ret && rw == READ) {
1272
stripes_allocated = 1;
1275
ce = search_cache_extent(&map_tree->cache_tree, logical);
1280
if (ce->start > logical || ce->start + ce->size < logical) {
1286
multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
1291
map = container_of(ce, struct map_lookup, ce);
1292
offset = logical - ce->start;
1295
if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
1296
BTRFS_BLOCK_GROUP_DUP)) {
1297
stripes_required = map->num_stripes;
1298
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1299
stripes_required = map->sub_stripes;
1302
if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)
1303
&& multi_ret && ((rw & WRITE) || mirror_num > 1) && raid_map_ret) {
1304
/* RAID[56] write or recovery. Return all stripes */
1305
stripes_required = map->num_stripes;
1307
/* Only allocate the map if we've already got a large enough multi_ret */
1308
if (stripes_allocated >= stripes_required) {
1309
raid_map = kmalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
1317
/* if our multi bio struct is too small, back off and try again */
1318
if (multi_ret && stripes_allocated < stripes_required) {
1319
stripes_allocated = stripes_required;
1326
* stripe_nr counts the total number of stripes we have to stride
1327
* to get to this block
1329
stripe_nr = stripe_nr / map->stripe_len;
1331
stripe_offset = stripe_nr * map->stripe_len;
1332
BUG_ON(offset < stripe_offset);
1334
/* stripe_offset is the offset of this block in its stripe*/
1335
stripe_offset = offset - stripe_offset;
1337
if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
1338
BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 |
1339
BTRFS_BLOCK_GROUP_RAID10 |
1340
BTRFS_BLOCK_GROUP_DUP)) {
1341
/* we limit the length of each bio to what fits in a stripe */
1342
*length = min_t(u64, ce->size - offset,
1343
map->stripe_len - stripe_offset);
1345
*length = ce->size - offset;
1351
multi->num_stripes = 1;
1353
if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1355
multi->num_stripes = map->num_stripes;
1356
else if (mirror_num)
1357
stripe_index = mirror_num - 1;
1359
stripe_index = stripe_nr % map->num_stripes;
1360
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1361
int factor = map->num_stripes / map->sub_stripes;
1363
stripe_index = stripe_nr % factor;
1364
stripe_index *= map->sub_stripes;
1367
multi->num_stripes = map->sub_stripes;
1368
else if (mirror_num)
1369
stripe_index += mirror_num - 1;
1371
stripe_nr = stripe_nr / factor;
1372
} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1374
multi->num_stripes = map->num_stripes;
1375
else if (mirror_num)
1376
stripe_index = mirror_num - 1;
1377
} else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
1378
BTRFS_BLOCK_GROUP_RAID6)) {
1383
u64 raid56_full_stripe_start;
1384
u64 full_stripe_len = nr_data_stripes(map) * map->stripe_len;
1387
* align the start of our data stripe in the logical
1390
raid56_full_stripe_start = offset / full_stripe_len;
1391
raid56_full_stripe_start *= full_stripe_len;
1393
/* get the data stripe number */
1394
stripe_nr = raid56_full_stripe_start / map->stripe_len;
1395
stripe_nr = stripe_nr / nr_data_stripes(map);
1397
/* Work out the disk rotation on this stripe-set */
1398
rot = stripe_nr % map->num_stripes;
1400
/* Fill in the logical address of each stripe */
1401
tmp = stripe_nr * nr_data_stripes(map);
1403
for (i = 0; i < nr_data_stripes(map); i++)
1404
raid_map[(i+rot) % map->num_stripes] =
1405
ce->start + (tmp + i) * map->stripe_len;
1407
raid_map[(i+rot) % map->num_stripes] = BTRFS_RAID5_P_STRIPE;
1408
if (map->type & BTRFS_BLOCK_GROUP_RAID6)
1409
raid_map[(i+rot+1) % map->num_stripes] = BTRFS_RAID6_Q_STRIPE;
1411
*length = map->stripe_len;
1414
multi->num_stripes = map->num_stripes;
1416
stripe_index = stripe_nr % nr_data_stripes(map);
1417
stripe_nr = stripe_nr / nr_data_stripes(map);
1420
* Mirror #0 or #1 means the original data block.
1421
* Mirror #2 is RAID5 parity block.
1422
* Mirror #3 is RAID6 Q block.
1425
stripe_index = nr_data_stripes(map) + mirror_num - 2;
1427
/* We distribute the parity blocks across stripes */
1428
stripe_index = (stripe_nr + stripe_index) % map->num_stripes;
1432
* after this do_div call, stripe_nr is the number of stripes
1433
* on this device we have to walk to find the data, and
1434
* stripe_index is the number of our device in the stripe array
1436
stripe_index = stripe_nr % map->num_stripes;
1437
stripe_nr = stripe_nr / map->num_stripes;
1439
BUG_ON(stripe_index >= map->num_stripes);
1441
for (i = 0; i < multi->num_stripes; i++) {
1442
multi->stripes[i].physical =
1443
map->stripes[stripe_index].physical + stripe_offset +
1444
stripe_nr * map->stripe_len;
1445
multi->stripes[i].dev = map->stripes[stripe_index].dev;
1454
sort_parity_stripes(multi, raid_map);
1455
*raid_map_ret = raid_map;
1461
struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
1464
struct btrfs_device *device;
1465
struct btrfs_fs_devices *cur_devices;
1467
cur_devices = root->fs_info->fs_devices;
1468
while (cur_devices) {
1470
!memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
1471
device = __find_device(&cur_devices->devices,
1476
cur_devices = cur_devices->seed;
1481
struct btrfs_device *
1482
btrfs_find_device_by_devid(struct btrfs_fs_devices *fs_devices,
1483
u64 devid, int instance)
1485
struct list_head *head = &fs_devices->devices;
1486
struct btrfs_device *dev;
1489
list_for_each_entry(dev, head, dev_list) {
1490
if (dev->devid == devid && num_found++ == instance)
1496
int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
1498
struct cache_extent *ce;
1499
struct map_lookup *map;
1500
struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1505
* During chunk recovering, we may fail to find block group's
1506
* corresponding chunk, we will rebuild it later
1508
ce = search_cache_extent(&map_tree->cache_tree, chunk_offset);
1509
if (!root->fs_info->is_chunk_recover)
1514
map = container_of(ce, struct map_lookup, ce);
1515
for (i = 0; i < map->num_stripes; i++) {
1516
if (!map->stripes[i].dev->writeable) {
1525
static struct btrfs_device *fill_missing_device(u64 devid)
1527
struct btrfs_device *device;
1529
device = kzalloc(sizeof(*device), GFP_NOFS);
1530
device->devid = devid;
1535
static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
1536
struct extent_buffer *leaf,
1537
struct btrfs_chunk *chunk)
1539
struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1540
struct map_lookup *map;
1541
struct cache_extent *ce;
1545
u8 uuid[BTRFS_UUID_SIZE];
1550
logical = key->offset;
1551
length = btrfs_chunk_length(leaf, chunk);
1553
ce = search_cache_extent(&map_tree->cache_tree, logical);
1555
/* already mapped? */
1556
if (ce && ce->start <= logical && ce->start + ce->size > logical) {
1560
num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
1561
map = kmalloc(btrfs_map_lookup_size(num_stripes), GFP_NOFS);
1565
map->ce.start = logical;
1566
map->ce.size = length;
1567
map->num_stripes = num_stripes;
1568
map->io_width = btrfs_chunk_io_width(leaf, chunk);
1569
map->io_align = btrfs_chunk_io_align(leaf, chunk);
1570
map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
1571
map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
1572
map->type = btrfs_chunk_type(leaf, chunk);
1573
map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
1575
for (i = 0; i < num_stripes; i++) {
1576
map->stripes[i].physical =
1577
btrfs_stripe_offset_nr(leaf, chunk, i);
1578
devid = btrfs_stripe_devid_nr(leaf, chunk, i);
1579
read_extent_buffer(leaf, uuid, (unsigned long)
1580
btrfs_stripe_dev_uuid_nr(chunk, i),
1582
map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
1584
if (!map->stripes[i].dev) {
1585
map->stripes[i].dev = fill_missing_device(devid);
1586
printf("warning, device %llu is missing\n",
1587
(unsigned long long)devid);
1591
ret = insert_cache_extent(&map_tree->cache_tree, &map->ce);
1597
static int fill_device_from_item(struct extent_buffer *leaf,
1598
struct btrfs_dev_item *dev_item,
1599
struct btrfs_device *device)
1603
device->devid = btrfs_device_id(leaf, dev_item);
1604
device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
1605
device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
1606
device->type = btrfs_device_type(leaf, dev_item);
1607
device->io_align = btrfs_device_io_align(leaf, dev_item);
1608
device->io_width = btrfs_device_io_width(leaf, dev_item);
1609
device->sector_size = btrfs_device_sector_size(leaf, dev_item);
1611
ptr = (unsigned long)btrfs_device_uuid(dev_item);
1612
read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1617
static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
1619
struct btrfs_fs_devices *fs_devices;
1622
fs_devices = root->fs_info->fs_devices->seed;
1623
while (fs_devices) {
1624
if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
1628
fs_devices = fs_devices->seed;
1631
fs_devices = find_fsid(fsid);
1637
ret = btrfs_open_devices(fs_devices, O_RDONLY);
1641
fs_devices->seed = root->fs_info->fs_devices->seed;
1642
root->fs_info->fs_devices->seed = fs_devices;
1647
static int read_one_dev(struct btrfs_root *root,
1648
struct extent_buffer *leaf,
1649
struct btrfs_dev_item *dev_item)
1651
struct btrfs_device *device;
1654
u8 fs_uuid[BTRFS_UUID_SIZE];
1655
u8 dev_uuid[BTRFS_UUID_SIZE];
1657
devid = btrfs_device_id(leaf, dev_item);
1658
read_extent_buffer(leaf, dev_uuid,
1659
(unsigned long)btrfs_device_uuid(dev_item),
1661
read_extent_buffer(leaf, fs_uuid,
1662
(unsigned long)btrfs_device_fsid(dev_item),
1665
if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
1666
ret = open_seed_devices(root, fs_uuid);
1671
device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1673
printk("warning devid %llu not found already\n",
1674
(unsigned long long)devid);
1675
device = kzalloc(sizeof(*device), GFP_NOFS);
1679
list_add(&device->dev_list,
1680
&root->fs_info->fs_devices->devices);
1683
fill_device_from_item(leaf, dev_item, device);
1684
device->dev_root = root->fs_info->dev_root;
1688
int btrfs_read_sys_array(struct btrfs_root *root)
1690
struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1691
struct extent_buffer *sb;
1692
struct btrfs_disk_key *disk_key;
1693
struct btrfs_chunk *chunk;
1694
struct btrfs_key key;
1701
sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
1702
BTRFS_SUPER_INFO_SIZE);
1705
btrfs_set_buffer_uptodate(sb);
1706
write_extent_buffer(sb, super_copy, 0, sizeof(*super_copy));
1707
array_end = ((u8 *)super_copy->sys_chunk_array) +
1708
btrfs_super_sys_array_size(super_copy);
1711
* we do this loop twice, once for the device items and
1712
* once for all of the chunks. This way there are device
1713
* structs filled in for every chunk
1715
ptr = super_copy->sys_chunk_array;
1717
while (ptr < array_end) {
1718
disk_key = (struct btrfs_disk_key *)ptr;
1719
btrfs_disk_key_to_cpu(&key, disk_key);
1721
len = sizeof(*disk_key);
1724
if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1725
chunk = (struct btrfs_chunk *)(ptr - (u8 *)super_copy);
1726
ret = read_one_chunk(root, &key, sb, chunk);
1729
num_stripes = btrfs_chunk_num_stripes(sb, chunk);
1730
len = btrfs_chunk_item_size(num_stripes);
1736
free_extent_buffer(sb);
1740
int btrfs_read_chunk_tree(struct btrfs_root *root)
1742
struct btrfs_path *path;
1743
struct extent_buffer *leaf;
1744
struct btrfs_key key;
1745
struct btrfs_key found_key;
1749
root = root->fs_info->chunk_root;
1751
path = btrfs_alloc_path();
1756
* Read all device items, and then all the chunk items. All
1757
* device items are found before any chunk item (their object id
1758
* is smaller than the lowest possible object id for a chunk
1759
* item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
1761
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1764
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1768
leaf = path->nodes[0];
1769
slot = path->slots[0];
1770
if (slot >= btrfs_header_nritems(leaf)) {
1771
ret = btrfs_next_leaf(root, path);
1778
btrfs_item_key_to_cpu(leaf, &found_key, slot);
1779
if (found_key.type == BTRFS_DEV_ITEM_KEY) {
1780
struct btrfs_dev_item *dev_item;
1781
dev_item = btrfs_item_ptr(leaf, slot,
1782
struct btrfs_dev_item);
1783
ret = read_one_dev(root, leaf, dev_item);
1785
} else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
1786
struct btrfs_chunk *chunk;
1787
chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
1788
ret = read_one_chunk(root, &found_key, leaf, chunk);
1796
btrfs_free_path(path);
1800
struct list_head *btrfs_scanned_uuids(void)
1805
static int rmw_eb(struct btrfs_fs_info *info,
1806
struct extent_buffer *eb, struct extent_buffer *orig_eb)
1809
unsigned long orig_off = 0;
1810
unsigned long dest_off = 0;
1811
unsigned long copy_len = eb->len;
1813
ret = read_whole_eb(info, eb, 0);
1817
if (eb->start + eb->len <= orig_eb->start ||
1818
eb->start >= orig_eb->start + orig_eb->len)
1821
* | ----- orig_eb ------- |
1822
* | ----- stripe ------- |
1823
* | ----- orig_eb ------- |
1824
* | ----- orig_eb ------- |
1826
if (eb->start > orig_eb->start)
1827
orig_off = eb->start - orig_eb->start;
1828
if (orig_eb->start > eb->start)
1829
dest_off = orig_eb->start - eb->start;
1831
if (copy_len > orig_eb->len - orig_off)
1832
copy_len = orig_eb->len - orig_off;
1833
if (copy_len > eb->len - dest_off)
1834
copy_len = eb->len - dest_off;
1836
memcpy(eb->data + dest_off, orig_eb->data + orig_off, copy_len);
1840
static void split_eb_for_raid56(struct btrfs_fs_info *info,
1841
struct extent_buffer *orig_eb,
1842
struct extent_buffer **ebs,
1843
u64 stripe_len, u64 *raid_map,
1846
struct extent_buffer *eb;
1847
u64 start = orig_eb->start;
1852
for (i = 0; i < num_stripes; i++) {
1853
if (raid_map[i] >= BTRFS_RAID5_P_STRIPE)
1856
eb = malloc(sizeof(struct extent_buffer) + stripe_len);
1859
memset(eb, 0, sizeof(struct extent_buffer) + stripe_len);
1861
eb->start = raid_map[i];
1862
eb->len = stripe_len;
1866
eb->dev_bytenr = (u64)-1;
1868
this_eb_start = raid_map[i];
1870
if (start > this_eb_start ||
1871
start + orig_eb->len < this_eb_start + stripe_len) {
1872
ret = rmw_eb(info, eb, orig_eb);
1875
memcpy(eb->data, orig_eb->data + eb->start - start, stripe_len);
1881
int write_raid56_with_parity(struct btrfs_fs_info *info,
1882
struct extent_buffer *eb,
1883
struct btrfs_multi_bio *multi,
1884
u64 stripe_len, u64 *raid_map)
1886
struct extent_buffer **ebs, *p_eb = NULL, *q_eb = NULL;
1890
int alloc_size = eb->len;
1892
ebs = kmalloc(sizeof(*ebs) * multi->num_stripes, GFP_NOFS);
1895
if (stripe_len > alloc_size)
1896
alloc_size = stripe_len;
1898
split_eb_for_raid56(info, eb, ebs, stripe_len, raid_map,
1899
multi->num_stripes);
1901
for (i = 0; i < multi->num_stripes; i++) {
1902
struct extent_buffer *new_eb;
1903
if (raid_map[i] < BTRFS_RAID5_P_STRIPE) {
1904
ebs[i]->dev_bytenr = multi->stripes[i].physical;
1905
ebs[i]->fd = multi->stripes[i].dev->fd;
1906
multi->stripes[i].dev->total_ios++;
1907
BUG_ON(ebs[i]->start != raid_map[i]);
1910
new_eb = kmalloc(sizeof(*eb) + alloc_size, GFP_NOFS);
1912
new_eb->dev_bytenr = multi->stripes[i].physical;
1913
new_eb->fd = multi->stripes[i].dev->fd;
1914
multi->stripes[i].dev->total_ios++;
1915
new_eb->len = stripe_len;
1917
if (raid_map[i] == BTRFS_RAID5_P_STRIPE)
1919
else if (raid_map[i] == BTRFS_RAID6_Q_STRIPE)
1925
pointers = kmalloc(sizeof(*pointers) * multi->num_stripes,
1929
ebs[multi->num_stripes - 2] = p_eb;
1930
ebs[multi->num_stripes - 1] = q_eb;
1932
for (i = 0; i < multi->num_stripes; i++)
1933
pointers[i] = ebs[i]->data;
1935
raid6_gen_syndrome(multi->num_stripes, stripe_len, pointers);
1938
ebs[multi->num_stripes - 1] = p_eb;
1939
memcpy(p_eb->data, ebs[0]->data, stripe_len);
1940
for (j = 1; j < multi->num_stripes - 1; j++) {
1941
for (i = 0; i < stripe_len; i += sizeof(unsigned long)) {
1942
*(unsigned long *)(p_eb->data + i) ^=
1943
*(unsigned long *)(ebs[j]->data + i);
1948
for (i = 0; i < multi->num_stripes; i++) {
1949
ret = write_extent_to_disk(ebs[i]);