- 根目录:
- fs
- btrfs
- 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.
*/
#include <linux/sched.h>
#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/buffer_head.h>
#include <linux/blkdev.h>
#include <linux/random.h>
#include <linux/iocontext.h>
#include <linux/capability.h>
#include <asm/div64.h>
#include "compat.h"
#include "ctree.h"
#include "extent_map.h"
#include "disk-io.h"
#include "transaction.h"
#include "print-tree.h"
#include "volumes.h"
#include "async-thread.h"
static int init_first_rw_device(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_device *device);
static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
static DEFINE_MUTEX(uuid_mutex);
static LIST_HEAD(fs_uuids);
static void lock_chunks(struct btrfs_root *root)
{
mutex_lock(&root->fs_info->chunk_mutex);
}
static void unlock_chunks(struct btrfs_root *root)
{
mutex_unlock(&root->fs_info->chunk_mutex);
}
static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device;
WARN_ON(fs_devices->opened);
while (!list_empty(&fs_devices->devices)) {
device = list_entry(fs_devices->devices.next,
struct btrfs_device, dev_list);
list_del(&device->dev_list);
kfree(device->name);
kfree(device);
}
kfree(fs_devices);
}
int btrfs_cleanup_fs_uuids(void)
{
struct btrfs_fs_devices *fs_devices;
while (!list_empty(&fs_uuids)) {
fs_devices = list_entry(fs_uuids.next,
struct btrfs_fs_devices, list);
list_del(&fs_devices->list);
free_fs_devices(fs_devices);
}
return 0;
}
static noinline struct btrfs_device *__find_device(struct list_head *head,
u64 devid, u8 *uuid)
{
struct btrfs_device *dev;
list_for_each_entry(dev, head, dev_list) {
if (dev->devid == devid &&
(!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
return dev;
}
}
return NULL;
}
static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
{
struct btrfs_fs_devices *fs_devices;
list_for_each_entry(fs_devices, &fs_uuids, list) {
if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
return fs_devices;
}
return NULL;
}
static void requeue_list(struct btrfs_pending_bios *pending_bios,
struct bio *head, struct bio *tail)
{
struct bio *old_head;
old_head = pending_bios->head;
pending_bios->head = head;
if (pending_bios->tail)
tail->bi_next = old_head;
else
pending_bios->tail = tail;
}
/*
* we try to collect pending bios for a device so we don't get a large
* number of procs sending bios down to the same device. This greatly
* improves the schedulers ability to collect and merge the bios.
*
* But, it also turns into a long list of bios to process and that is sure
* to eventually make the worker thread block. The solution here is to
* make some progress and then put this work struct back at the end of
* the list if the block device is congested. This way, multiple devices
* can make progress from a single worker thread.
*/
static noinline int run_scheduled_bios(struct btrfs_device *device)
{
struct bio *pending;
struct backing_dev_info *bdi;
struct btrfs_fs_info *fs_info;
struct btrfs_pending_bios *pending_bios;
struct bio *tail;
struct bio *cur;
int again = 0;
unsigned long num_run;
unsigned long batch_run = 0;
unsigned long limit;
unsigned long last_waited = 0;
int force_reg = 0;
struct blk_plug plug;
/*
* this function runs all the bios we've collected for
* a particular device. We don't want to wander off to
* another device without first sending all of these down.
* So, setup a plug here and finish it off before we return
*/
blk_start_plug(&plug);
bdi = blk_get_backing_dev_info(device->bdev);
fs_info = device->dev_root->fs_info;
limit = btrfs_async_submit_limit(fs_info);
limit = limit * 2 / 3;
loop:
spin_lock(&device->io_lock);
loop_lock:
num_run = 0;
/* take all the bios off the list at once and process them
* later on (without the lock held). But, remember the
* tail and other pointers so the bios can be properly reinserted
* into the list if we hit congestion
*/
if (!force_reg && device->pending_sync_bios.head) {
pending_bios = &device->pending_sync_bios;
force_reg = 1;
} else {
pending_bios = &device->pending_bios;
force_reg = 0;
}
pending = pending_bios->head;
tail = pending_bios->tail;
WARN_ON(pending && !tail);
/*
* if pending was null this time around, no bios need processing
* at all and we can stop. Otherwise it'll loop back up again
* and do an additional check so no bios are missed.
*
* device->running_pending is used to synchronize with the
* schedule_bio code.
*/
if (device->pending_sync_bios.head == NULL &&
device->pending_bios.head == NULL) {
again = 0;
device->running_pending = 0;
} else {
again = 1;
device->running_pending = 1;
}
pending_bios->head = NULL;
pending_bios->tail = NULL;
spin_unlock(&device->io_lock);
while (pending) {
rmb();
/* we want to work on both lists, but do more bios on the
* sync list than the regular list
*/
if ((num_run > 32 &&
pending_bios != &device->pending_sync_bios &&
device->pending_sync_bios.head) ||
(num_run > 64 && pending_bios == &device->pending_sync_bios &&
device->pending_bios.head)) {
spin_lock(&device->io_lock);
requeue_list(pending_bios, pending, tail);
goto loop_lock;
}
cur = pending;
pending = pending->bi_next;
cur->bi_next = NULL;
atomic_dec(&fs_info->nr_async_bios);
if (atomic_read(&fs_info->nr_async_bios) < limit &&
waitqueue_active(&fs_info->async_submit_wait))
wake_up(&fs_info->async_submit_wait);
BUG_ON(atomic_read(&cur->bi_cnt) == 0);
submit_bio(cur->bi_rw, cur);
num_run++;
batch_run++;
if (need_resched())
cond_resched();
/*
* we made progress, there is more work to do and the bdi
* is now congested. Back off and let other work structs
* run instead
*/
if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
fs_info->fs_devices->open_devices > 1) {
struct io_context *ioc;
ioc = current->io_context;
/*
* the main goal here is that we don't want to
* block if we're going to be able to submit
* more requests without blocking.
*
* This code does two great things, it pokes into
* the elevator code from a filesystem _and_
* it makes assumptions about how batching works.
*/
if (ioc && ioc->nr_batch_requests > 0 &&
time_before(jiffies, ioc->last_waited + HZ/50UL) &&
(last_waited == 0 ||
ioc->last_waited == last_waited)) {
/*
* we want to go through our batch of
* requests and stop. So, we copy out
* the ioc->last_waited time and test
* against it before looping
*/
last_waited = ioc->last_waited;
if (need_resched())
cond_resched();
continue;
}
spin_lock(&device->io_lock);
requeue_list(pending_bios, pending, tail);
device->running_pending = 1;
spin_unlock(&device->io_lock);
btrfs_requeue_work(&device->work);
goto done;
}
}
cond_resched();
if (again)
goto loop;
spin_lock(&device->io_lock);
if (device->pending_bios.head || device->pending_sync_bios.head)
goto loop_lock;
spin_unlock(&device->io_lock);
done:
blk_finish_plug(&plug);
return 0;
}
static void pending_bios_fn(struct btrfs_work *work)
{
struct btrfs_device *device;
device = container_of(work, struct btrfs_device, work);
run_scheduled_bios(device);
}
static noinline 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);
char *name;
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);
INIT_LIST_HEAD(&fs_devices->alloc_list);
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;
mutex_init(&fs_devices->device_list_mutex);
device = NULL;
} else {
device = __find_device(&fs_devices->devices, devid,
disk_super->dev_item.uuid);
}
if (!device) {
if (fs_devices->opened)
return -EBUSY;
device = kzalloc(sizeof(*device), GFP_NOFS);
if (!device) {
/* we can safely leave the fs_devices entry around */
return -ENOMEM;
}
device->devid = devid;
device->work.func = pending_bios_fn;
memcpy(device->uuid, disk_super->dev_item.uuid,
BTRFS_UUID_SIZE);
spin_lock_init(&device->io_lock);
device->name = kstrdup(path, GFP_NOFS);
if (!device->name) {
kfree(device);
return -ENOMEM;
}
INIT_LIST_HEAD(&device->dev_alloc_list);
mutex_lock(&fs_devices->device_list_mutex);
list_add_rcu(&device->dev_list, &fs_devices->devices);
mutex_unlock(&fs_devices->device_list_mutex);
device->fs_devices = fs_devices;
fs_devices->num_devices++;
} else if (!device->name || strcmp(device->name, path)) {
name = kstrdup(path, GFP_NOFS);
if (!name)
return -ENOMEM;
kfree(device->name);
device->name = name;
if (device->missing) {
fs_devices->missing_devices--;
device->missing = 0;
}
}
if (found_transid > fs_devices->latest_trans) {
fs_devices->latest_devid = devid;
fs_devices->latest_trans = found_transid;
}
*fs_devices_ret = fs_devices;
return 0;
}
static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
{
struct btrfs_fs_devices *fs_devices;
struct btrfs_device *device;
struct btrfs_device *orig_dev;
fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
if (!fs_devices)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&fs_devices->devices);
INIT_LIST_HEAD(&fs_devices->alloc_list);
INIT_LIST_HEAD(&fs_devices->list);
mutex_init(&fs_devices->device_list_mutex);
fs_devices->latest_devid = orig->latest_devid;
fs_devices->latest_trans = orig->latest_trans;
memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
/* We have held the volume lock, it is safe to get the devices. */
list_for_each_entry(orig_dev, &orig->devices, dev_list) {
device = kzalloc(sizeof(*device), GFP_NOFS);
if (!device)
goto error;
device->name = kstrdup(orig_dev->name, GFP_NOFS);
if (!device->name) {
kfree(device);
goto error;
}
device->devid = orig_dev->devid;
device->work.func = pending_bios_fn;
memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
spin_lock_init(&device->io_lock);
INIT_LIST_HEAD(&device->dev_list);
INIT_LIST_HEAD(&device->dev_alloc_list);
list_add(&device->dev_list, &fs_devices->devices);
device->fs_devices = fs_devices;
fs_devices->num_devices++;
}
return fs_devices;
error:
free_fs_devices(fs_devices);
return ERR_PTR(-ENOMEM);
}
int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device, *next;
mutex_lock(&uuid_mutex);
again:
/* This is the initialized path, it is safe to release the devices. */
list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
if (device->in_fs_metadata)
continue;
if (device->bdev) {
blkdev_put(device->bdev, device->mode);
device->bdev = NULL;
fs_devices->open_devices--;
}
if (device->writeable) {
list_del_init(&device->dev_alloc_list);
device->writeable = 0;
fs_devices->rw_devices--;
}
list_del_init(&device->dev_list);
fs_devices->num_devices--;
kfree(device->name);
kfree(device);
}
if (fs_devices->seed) {
fs_devices = fs_devices->seed;
goto again;
}
mutex_unlock(&uuid_mutex);
return 0;
}
static void __free_device(struct work_struct *work)
{
struct btrfs_device *device;
device = container_of(work, struct btrfs_device, rcu_work);
if (device->bdev)
blkdev_put(device->bdev, device->mode);
kfree(device->name);
kfree(device);
}
static void free_device(struct rcu_head *head)
{
struct btrfs_device *device;
device = container_of(head, struct btrfs_device, rcu);
INIT_WORK(&device->rcu_work, __free_device);
schedule_work(&device->rcu_work);
}
static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device;
if (--fs_devices->opened > 0)
return 0;
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list) {
struct btrfs_device *new_device;
if (device->bdev)
fs_devices->open_devices--;
if (device->writeable) {
list_del_init(&device->dev_alloc_list);
fs_devices->rw_devices--;
}
if (device->can_discard)
fs_devices->num_can_discard--;
new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
BUG_ON(!new_device);
memcpy(new_device, device, sizeof(*new_device));
new_device->name = kstrdup(device->name, GFP_NOFS);
BUG_ON(device->name && !new_device->name);
new_device->bdev = NULL;
new_device->writeable = 0;
new_device->in_fs_metadata = 0;
new_device->can_discard = 0;
spin_lock_init(&new_device->io_lock);
list_replace_rcu(&device->dev_list, &new_device->dev_list);
call_rcu(&device->rcu, free_device);
}
mutex_unlock(&fs_devices->device_list_mutex);
WARN_ON(fs_devices->open_devices);
WARN_ON(fs_devices->rw_devices);
fs_devices->opened = 0;
fs_devices->seeding = 0;
return 0;
}
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_fs_devices *seed_devices = NULL;
int ret;
mutex_lock(&uuid_mutex);
ret = __btrfs_close_devices(fs_devices);
if (!fs_devices->opened) {
seed_devices = fs_devices->seed;
fs_devices->seed = NULL;
}
mutex_unlock(&uuid_mutex);
while (seed_devices) {
fs_devices = seed_devices;
seed_devices = fs_devices->seed;
__btrfs_close_devices(fs_devices);
free_fs_devices(fs_devices);
}
/*
* Wait for rcu kworkers under __btrfs_close_devices
* to finish all blkdev_puts so device is really
* free when umount is done.
*/
rcu_barrier();
return ret;
}
static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
fmode_t flags, void *holder)
{
struct request_queue *q;
struct block_device *bdev;
struct list_head *head = &fs_devices->devices;
struct btrfs_device *device;
struct block_device *latest_bdev = NULL;
struct buffer_head *bh;
struct btrfs_super_block *disk_super;
u64 latest_devid = 0;
u64 latest_transid = 0;
u64 devid;
int seeding = 1;
int ret = 0;
flags |= FMODE_EXCL;
list_for_each_entry(device, head, dev_list) {
if (device->bdev)
continue;
if (!device->name)
continue;
bdev = blkdev_get_by_path(device->name, flags, holder);
if (IS_ERR(bdev)) {
printk(KERN_INFO "open %s failed\n", device->name);
goto error;
}
set_blocksize(bdev, 4096);
bh = btrfs_read_dev_super(bdev);
if (!bh) {
ret = -EINVAL;
goto error_close;
}
disk_super = (struct btrfs_super_block *)bh->b_data;
devid = btrfs_stack_device_id(&disk_super->dev_item);
if (devid != device->devid)
goto error_brelse;
if (memcmp(device->uuid, disk_super->dev_item.uuid,
BTRFS_UUID_SIZE))
goto error_brelse;
device->generation = btrfs_super_generation(disk_super);
if (!latest_transid || device->generation > latest_transid) {
latest_devid = devid;
latest_transid = device->generation;
latest_bdev = bdev;
}
if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
device->writeable = 0;
} else {
device->writeable = !bdev_read_only(bdev);
seeding = 0;
}
q = bdev_get_queue(bdev);
if (blk_queue_discard(q)) {
device->can_discard = 1;
fs_devices->num_can_discard++;
}
device->bdev = bdev;
device->in_fs_metadata = 0;
device->mode = flags;
if (!blk_queue_nonrot(bdev_get_queue(bdev)))
fs_devices->rotating = 1;
fs_devices->open_devices++;
if (device->writeable) {
fs_devices->rw_devices++;
list_add(&device->dev_alloc_list,
&fs_devices->alloc_list);
}
brelse(bh);
continue;
error_brelse:
brelse(bh);
error_close:
blkdev_put(bdev, flags);
error:
continue;
}
if (fs_devices->open_devices == 0) {
ret = -EIO;
goto out;
}
fs_devices->seeding = seeding;
fs_devices->opened = 1;
fs_devices->latest_bdev = latest_bdev;
fs_devices->latest_devid = latest_devid;
fs_devices->latest_trans = latest_transid;
fs_devices->total_rw_bytes = 0;
out:
return ret;
}
int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
fmode_t flags, void *holder)
{
int ret;
mutex_lock(&uuid_mutex);
if (fs_devices->opened) {
fs_devices->opened++;
ret = 0;
} else {
ret = __btrfs_open_devices(fs_devices, flags, holder);
}
mutex_unlock(&uuid_mutex);
return ret;
}
int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
struct btrfs_fs_devices **fs_devices_ret)
{
struct btrfs_super_block *disk_super;
struct block_device *bdev;
struct buffer_head *bh;
int ret;
u64 devid;
u64 transid;
mutex_lock(&uuid_mutex);
flags |= FMODE_EXCL;
bdev = blkdev_get_by_path(path, flags, holder);
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
goto error;
}
ret = set_blocksize(bdev, 4096);
if (ret)
goto error_close;
bh = btrfs_read_dev_super(bdev);
if (!bh) {
ret = -EINVAL;
goto error_close;
}
disk_super = (struct btrfs_super_block *)bh->b_data;
devid = btrfs_stack_device_id(&disk_super->dev_item);
transid = btrfs_super_generation(disk_super);
if (disk_super->label[0])
printk(KERN_INFO "device label %s ", disk_super->label);
else
printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
printk(KERN_CONT "devid %llu transid %llu %s\n",
(unsigned long long)devid, (unsigned long long)transid, path);
ret = device_list_add(path, disk_super, devid, fs_devices_ret);
brelse(bh);
error_close:
blkdev_put(bdev, flags);
error:
mutex_unlock(&uuid_mutex);
return ret;
}
/* helper to account the used device space in the range */
int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
u64 end, u64 *length)
{
struct btrfs_key key;
struct btrfs_root *root = device->dev_root;
struct btrfs_dev_extent *dev_extent;
struct btrfs_path *path;
u64 extent_end;
int ret;
int slot;
struct extent_buffer *l;
*length = 0;
if (start >= device->total_bytes)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 2;
key.objectid = device->devid;
key.offset = start;
key.type = BTRFS_DEV_EXTENT_KEY;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
ret = btrfs_previous_item(root, path, key.objectid, key.type);
if (ret < 0)
goto out;
}
while (1) {
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
break;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.objectid < device->devid)
goto next;
if (key.objectid > device->devid)
break;
if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
goto next;
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
extent_end = key.offset + btrfs_dev_extent_length(l,
dev_extent);
if (key.offset <= start && extent_end > end) {
*length = end - start + 1;
break;
} else if (key.offset <= start && extent_end > start)
*length += extent_end - start;
else if (key.offset > start && extent_end <= end)
*length += extent_end - key.offset;
else if (key.offset > start && key.offset <= end) {
*length += end - key.offset + 1;
break;
} else if (key.offset > end)
break;
next:
path->slots[0]++;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
/*
* find_free_dev_extent - find free space in the specified device
* @trans: transaction handler
* @device: the device which we search the free space in
* @num_bytes: the size of the free space that we need
* @start: store the start of the free space.
* @len: the size of the free space. that we find, or the size of the max
* free space if we don't find suitable free space
*
* 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
*
* @start is used to store the start of the free space if we find. But if we
* don't find suitable free space, it will be used to store the start position
* of the max free space.
*
* @len is used to store the size of the free space that we find.
* But if we don't find suitable free space, it is used to store the size of
* the max free space.
*/
int find_free_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 num_bytes,
u64 *start, u64 *len)
{
struct btrfs_key key;
struct btrfs_root *root = device->dev_root;
struct btrfs_dev_extent *dev_extent;
struct btrfs_path *path;
u64 hole_size;
u64 max_hole_start;
u64 max_hole_size;
u64 extent_end;
u64 search_start;
u64 search_end = device->total_bytes;
int ret;
int slot;
struct extent_buffer *l;
/* 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(root->fs_info->alloc_start, 1024ull * 1024);
max_hole_start = search_start;
max_hole_size = 0;
if (search_start >= search_end) {
ret = -ENOSPC;
goto error;
}
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto error;
}
path->reada = 2;
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 out;
if (ret > 0) {
ret = btrfs_previous_item(root, path, key.objectid, key.type);
if (ret < 0)
goto out;
}
while (1) {
l = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(l)) {
ret = btrfs_next_leaf(root, path);
if (ret == 0)
continue;
if (ret < 0)
goto out;
break;
}
btrfs_item_key_to_cpu(l, &key, slot);
if (key.objectid < device->devid)
goto next;
if (key.objectid > device->devid)
break;
if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
goto next;
if (key.offset > search_start) {
hole_size = key.offset - search_start;
if (hole_size > max_hole_size) {
max_hole_start = search_start;
max_hole_size = hole_size;
}
/*
* If this free space is greater than which we need,
* it must be the max free space that we have found
* until now, so max_hole_start must point to the start
* of this free space and the length of this free space
* is stored in max_hole_size. Thus, we return
* max_hole_start and max_hole_size and go back to the
* caller.
*/
if (hole_size >= num_bytes) {
ret = 0;
goto out;
}
}
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
extent_end = key.offset + btrfs_dev_extent_length(l,
dev_extent);
if (extent_end > search_start)
search_start = extent_end;
next:
path->slots[0]++;
cond_resched();
}
hole_size = search_end- search_start;
if (hole_size > max_hole_size) {
max_hole_start = search_start;
max_hole_size = hole_size;
}
/* See above. */
if (hole_size < num_bytes)
ret = -ENOSPC;
else
ret = 0;
out:
btrfs_free_path(path);
error:
*start = max_hole_start;
if (len)
*len = max_hole_size;
return ret;
}
static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
struct btrfs_device *device,
u64 start)
{
int ret;
struct btrfs_path *path;
struct btrfs_root *root = device->dev_root;
struct btrfs_key key;
struct btrfs_key found_key;
struct extent_buffer *leaf = NULL;
struct btrfs_dev_extent *extent = NULL;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = device->devid;
key.offset = start;
key.type = BTRFS_DEV_EXTENT_KEY;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret > 0) {
ret = btrfs_previous_item(root, path, key.objectid,
BTRFS_DEV_EXTENT_KEY);
if (ret)
goto out;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_extent);
BUG_ON(found_key.offset > start || found_key.offset +
btrfs_dev_extent_length(leaf, extent) < start);
} else if (ret == 0) {
leaf = path->nodes[0];
extent = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_extent);
}
BUG_ON(ret);
if (device->bytes_used > 0)
device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
ret = btrfs_del_item(trans, root, path);
out:
btrfs_free_path(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 start, u64 num_bytes)
{
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;
WARN_ON(!device->in_fs_metadata);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
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);
btrfs_free_path(path);
return ret;
}
static noinline 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 noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
{
int ret;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_path *path;
root = root->fs_info->chunk_root;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
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_free_path(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;
root = root->fs_info->chunk_root;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = device->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);
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;
}
static int btrfs_rm_dev_item(struct btrfs_root *root,
struct btrfs_device *device)
{
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_trans_handle *trans;
root = root->fs_info->chunk_root;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.type = BTRFS_DEV_ITEM_KEY;
key.offset = device->devid;
lock_chunks(root);
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = -ENOENT;
goto out;
}
ret = btrfs_del_item(trans, root, path);
if (ret)
goto out;
out:
btrfs_free_path(path);
unlock_chunks(root);
btrfs_commit_transaction(trans, root);
return ret;
}
int btrfs_rm_device(struct btrfs_root *root, char *device_path)
{
struct btrfs_device *device;
struct btrfs_device *next_device;
struct block_device *bdev;
struct buffer_head *bh = NULL;
struct btrfs_super_block *disk_super;
struct btrfs_fs_devices *cur_devices;
u64 all_avail;
u64 devid;
u64 num_devices;
u8 *dev_uuid;
int ret = 0;
bool clear_super = false;
mutex_lock(&uuid_mutex);
mutex_lock(&root->fs_info->volume_mutex);
all_avail = root->fs_info->avail_data_alloc_bits |
root->fs_info->avail_system_alloc_bits |
root->fs_info->avail_metadata_alloc_bits;
if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
root->fs_info->fs_devices->num_devices <= 4) {
printk(KERN_ERR "btrfs: unable to go below four devices "
"on raid10\n");
ret = -EINVAL;
goto out;
}
if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
root->fs_info->fs_devices->num_devices <= 2) {
printk(KERN_ERR "btrfs: unable to go below two "
"devices on raid1\n");
ret = -EINVAL;
goto out;
}
if (strcmp(device_path, "missing") == 0) {
struct list_head *devices;
struct btrfs_device *tmp;
device = NULL;
devices = &root->fs_info->fs_devices->devices;
/*
* It is safe to read the devices since the volume_mutex
* is held.
*/
list_for_each_entry(tmp, devices, dev_list) {
if (tmp->in_fs_metadata && !tmp->bdev) {
device = tmp;
break;
}
}
bdev = NULL;
bh = NULL;
disk_super = NULL;
if (!device) {
printk(KERN_ERR "btrfs: no missing devices found to "
"remove\n");
goto out;
}
} else {
bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
root->fs_info->bdev_holder);
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
goto out;
}
set_blocksize(bdev, 4096);
bh = btrfs_read_dev_super(bdev);
if (!bh) {
ret = -EINVAL;
goto error_close;
}
disk_super = (struct btrfs_super_block *)bh->b_data;
devid = btrfs_stack_device_id(&disk_super->dev_item);
dev_uuid = disk_super->dev_item.uuid;
device = btrfs_find_device(root, devid, dev_uuid,
disk_super->fsid);
if (!device) {
ret = -ENOENT;
goto error_brelse;
}
}
if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
printk(KERN_ERR "btrfs: unable to remove the only writeable "
"device\n");
ret = -EINVAL;
goto error_brelse;
}
if (device->writeable) {
lock_chunks(root);
list_del_init(&device->dev_alloc_list);
unlock_chunks(root);
root->fs_info->fs_devices->rw_devices--;
clear_super = true;
}
ret = btrfs_shrink_device(device, 0);
if (ret)
goto error_undo;
ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
if (ret)
goto error_undo;
device->in_fs_metadata = 0;
btrfs_scrub_cancel_dev(root, device);
/*
* the device list mutex makes sure that we don't change
* the device list while someone else is writing out all
* the device supers.
*/
cur_devices = device->fs_devices;
mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
list_del_rcu(&device->dev_list);
device->fs_devices->num_devices--;
if (device->missing)
root->fs_info->fs_devices->missing_devices--;
next_device = list_entry(root->fs_info->fs_devices->devices.next,
struct btrfs_device, dev_list);
if (device->bdev == root->fs_info->sb->s_bdev)
root->fs_info->sb->s_bdev = next_device->bdev;
if (device->bdev == root->fs_info->fs_devices->latest_bdev)
root->fs_info->fs_devices->latest_bdev = next_device->bdev;
if (device->bdev)
device->fs_devices->open_devices--;
call_rcu(&device->rcu, free_device);
mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
if (cur_devices->open_devices == 0) {
struct btrfs_fs_devices *fs_devices;
fs_devices = root->fs_info->fs_devices;
while (fs_devices) {
if (fs_devices->seed == cur_devices)
break;
fs_devices = fs_devices->seed;
}
fs_devices->seed = cur_devices->seed;
cur_devices->seed = NULL;
lock_chunks(root);
__btrfs_close_devices(cur_devices);
unlock_chunks(root);
free_fs_devices(cur_devices);
}
/*
* at this point, the device is zero sized. We want to
* remove it from the devices list and zero out the old super
*/
if (clear_super) {
/* make sure this device isn't detected as part of
* the FS anymore
*/
memset(&disk_super->magic, 0, sizeof(disk_super->magic));
set_buffer_dirty(bh);
sync_dirty_buffer(bh);
}
ret = 0;
error_brelse:
brelse(bh);
error_close:
if (bdev)
blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
out:
mutex_unlock(&root->fs_info->volume_mutex);
mutex_unlock(&uuid_mutex);
return ret;
error_undo:
if (device->writeable) {
lock_chunks(root);
list_add(&device->dev_alloc_list,
&root->fs_info->fs_devices->alloc_list);
unlock_chunks(root);
root->fs_info->fs_devices->rw_devices++;
}
goto error_brelse;
}
/*
* does all the dirty work required for changing file system's UUID.
*/
static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
struct btrfs_fs_devices *old_devices;
struct btrfs_fs_devices *seed_devices;
struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
struct btrfs_device *device;
u64 super_flags;
BUG_ON(!mutex_is_locked(&uuid_mutex));
if (!fs_devices->seeding)
return -EINVAL;
seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
if (!seed_devices)
return -ENOMEM;
old_devices = clone_fs_devices(fs_devices);
if (IS_ERR(old_devices)) {
kfree(seed_devices);
return PTR_ERR(old_devices);
}
list_add(&old_devices->list, &fs_uuids);
memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
seed_devices->opened = 1;
INIT_LIST_HEAD(&seed_devices->devices);
INIT_LIST_HEAD(&seed_devices->alloc_list);
mutex_init(&seed_devices->device_list_mutex);
mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
synchronize_rcu);
mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
list_for_each_entry(device, &seed_devices->devices, dev_list) {
device->fs_devices = seed_devices;
}
fs_devices->seeding = 0;
fs_devices->num_devices = 0;
fs_devices->open_devices = 0;
fs_devices->seed = seed_devices;
generate_random_uuid(fs_devices->fsid);
memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
super_flags = btrfs_super_flags(disk_super) &
~BTRFS_SUPER_FLAG_SEEDING;
btrfs_set_super_flags(disk_super, super_flags);
return 0;
}
/*
* strore the expected generation for seed devices in device items.
*/
static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dev_item *dev_item;
struct btrfs_device *device;
struct btrfs_key key;
u8 fs_uuid[BTRFS_UUID_SIZE];
u8 dev_uuid[BTRFS_UUID_SIZE];
u64 devid;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
root = root->fs_info->chunk_root;
key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
key.offset = 0;
key.type = BTRFS_DEV_ITEM_KEY;
while (1) {
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0)
goto error;
leaf = path->nodes[0];
next_slot:
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret > 0)
break;
if (ret < 0)
goto error;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
btrfs_release_path(path);
continue;
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
key.type != BTRFS_DEV_ITEM_KEY)
break;
dev_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_dev_item);
devid = btrfs_device_id(leaf, dev_item);
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);
device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
BUG_ON(!device);
if (device->fs_devices->seeding) {
btrfs_set_device_generation(leaf, dev_item,
device->generation);
btrfs_mark_buffer_dirty(leaf);
}
path->slots[0]++;
goto next_slot;
}
ret = 0;
error:
btrfs_free_path(path);
return ret;
}
int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
{
struct request_queue *q;
struct btrfs_trans_handle *trans;
struct btrfs_device *device;
struct block_device *bdev;
struct list_head *devices;
struct super_block *sb = root->fs_info->sb;
u64 total_bytes;
int seeding_dev = 0;
int ret = 0;
if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
return -EINVAL;
bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
root->fs_info->bdev_holder);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
if (root->fs_info->fs_devices->seeding) {
seeding_dev = 1;
down_write(&sb->s_umount);
mutex_lock(&uuid_mutex);
}
filemap_write_and_wait(bdev->bd_inode->i_mapping);
mutex_lock(&root->fs_info->volume_mutex);
devices = &root->fs_info->fs_devices->devices;
/*
* we have the volume lock, so we don't need the extra
* device list mutex while reading the list here.
*/
list_for_each_entry(device, devices, dev_list) {
if (device->bdev == bdev) {
ret = -EEXIST;
goto error;
}
}
device = kzalloc(sizeof(*device), GFP_NOFS);
if (!device) {
/* we can safely leave the fs_devices entry around */
ret = -ENOMEM;
goto error;
}
device->name = kstrdup(device_path, GFP_NOFS);
if (!device->name) {
kfree(device);
ret = -ENOMEM;
goto error;
}
ret = find_next_devid(root, &device->devid);
if (ret) {
kfree(device->name);
kfree(device);
goto error;
}
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
kfree(device->name);
kfree(device);
ret = PTR_ERR(trans);
goto error;
}
lock_chunks(root);
q = bdev_get_queue(bdev);
if (blk_queue_discard(q))
device->can_discard = 1;
device->writeable = 1;
device->work.func = pending_bios_fn;
generate_random_uuid(device->uuid);
spin_lock_init(&device->io_lock);
device->generation = trans->transid;
device->io_width = root->sectorsize;
device->io_align = root->sectorsize;
device->sector_size = root->sectorsize;
device->total_bytes = i_size_read(bdev->bd_inode);
device->disk_total_bytes = device->total_bytes;
device->dev_root = root->fs_info->dev_root;
device->bdev = bdev;
device->in_fs_metadata = 1;
device->mode = FMODE_EXCL;
set_blocksize(device->bdev, 4096);
if (seeding_dev) {
sb->s_flags &= ~MS_RDONLY;
ret = btrfs_prepare_sprout(trans, root);
BUG_ON(ret);
}
device->fs_devices = root->fs_info->fs_devices;
/*
* we don't want write_supers to jump in here with our device
* half setup
*/
mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
list_add(&device->dev_alloc_list,
&root->fs_info->fs_devices->alloc_list);
root->fs_info->fs_devices->num_devices++;
root->fs_info->fs_devices->open_devices++;
root->fs_info->fs_devices->rw_devices++;
if (device->can_discard)
root->fs_info->fs_devices->num_can_discard++;
root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
if (!blk_queue_nonrot(bdev_get_queue(bdev)))
root->fs_info->fs_devices->rotating = 1;
total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
btrfs_set_super_total_bytes(&root->fs_info->super_copy,
total_bytes + device->total_bytes);
total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
btrfs_set_super_num_devices(&root->fs_info->super_copy,
total_bytes + 1);
mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
if (seeding_dev) {
ret = init_first_rw_device(trans, root, device);
BUG_ON(ret);
ret = btrfs_finish_sprout(trans, root);
BUG_ON(ret);
} else {
ret = btrfs_add_device(trans, root, device);
}
/*
* we've got more storage, clear any full flags on the space
* infos
*/
btrfs_clear_space_info_full(root->fs_info);
unlock_chunks(root);
btrfs_commit_transaction(trans, root);
if (seeding_dev) {
mutex_unlock(&uuid_mutex);
up_write(&sb->s_umount);
ret = btrfs_relocate_sys_chunks(root);
BUG_ON(ret);
}
out:
mutex_unlock(&root->fs_info->volume_mutex);
return ret;
error:
blkdev_put(bdev, FMODE_EXCL);
if (seeding_dev) {
mutex_unlock(&uuid_mutex);
up_write(&sb->s_umount);
}
goto out;
}
static noinline 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->disk_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;
}
static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 new_size)
{
struct btrfs_super_block *super_copy =
&device->dev_root->fs_info->super_copy;
u64 old_total = btrfs_super_total_bytes(super_copy);
u64 diff = new_size - device->total_bytes;
if (!device->writeable)
return -EACCES;
if (new_size <= device->total_bytes)
return -EINVAL;
btrfs_set_super_total_bytes(super_copy, old_total + diff);
device->fs_devices->total_rw_bytes += diff;
device->total_bytes = new_size;
device->disk_total_bytes = new_size;
btrfs_clear_space_info_full(device->dev_root->fs_info);
return btrfs_update_device(trans, device);
}
int btrfs_grow_device(struct btrfs_trans_handle *trans,
struct btrfs_device *device, u64 new_size)
{
int ret;
lock_chunks(device->dev_root);
ret = __btrfs_grow_device(trans, device, new_size);
unlock_chunks(device->dev_root);
return ret;
}
static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 chunk_tree, u64 chunk_objectid,
u64 chunk_offset)
{
int ret;
struct btrfs_path *path;
struct btrfs_key key;
root = root->fs_info->chunk_root;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = chunk_objectid;
key.offset = chunk_offset;
key.type = BTRFS_CHUNK_ITEM_KEY;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
BUG_ON(ret);
ret = btrfs_del_item(trans, root, path);
btrfs_free_path(path);
return ret;
}
static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
chunk_offset)
{
struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
struct btrfs_disk_key *disk_key;
struct btrfs_chunk *chunk;
u8 *ptr;
int ret = 0;
u32 num_stripes;
u32 array_size;
u32 len = 0;
u32 cur;
struct btrfs_key key;
array_size = btrfs_super_sys_array_size(super_copy);
ptr = super_copy->sys_chunk_array;
cur = 0;
while (cur < array_size) {
disk_key = (struct btrfs_disk_key *)ptr;
btrfs_disk_key_to_cpu(&key, disk_key);
len = sizeof(*disk_key);
if (key.type == BTRFS_CHUNK_ITEM_KEY) {
chunk = (struct btrfs_chunk *)(ptr + len);
num_stripes = btrfs_stack_chunk_num_stripes(chunk);
len += btrfs_chunk_item_size(num_stripes);
} else {
ret = -EIO;
break;
}
if (key.objectid == chunk_objectid &&
key.offset == chunk_offset) {
memmove(ptr, ptr + len, array_size - (cur + len));
array_size -= len;
btrfs_set_super_sys_array_size(super_copy, array_size);
} else {
ptr += len;
cur += len;
}
}
return ret;
}
static int btrfs_relocate_chunk(struct btrfs_root *root,
u64 chunk_tree, u64 chunk_objectid,
u64 chunk_offset)
{
struct extent_map_tree *em_tree;
struct btrfs_root *extent_root;
struct btrfs_trans_handle *trans;
struct extent_map *em;
struct map_lookup *map;
int ret;
int i;
root = root->fs_info->chunk_root;
extent_root = root->fs_info->extent_root;
em_tree = &root->fs_info->mapping_tree.map_tree;
ret = btrfs_can_relocate(extent_root, chunk_offset);
if (ret)
return -ENOSPC;
/* step one, relocate all the extents inside this chunk */
ret = btrfs_relocate_block_group(extent_root, chunk_offset);
if (ret)
return ret;
trans = btrfs_start_transaction(root, 0);
BUG_ON(IS_ERR(trans));
lock_chunks(root);
/*
* step two, delete the device extents and the
* chunk tree entries
*/
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, chunk_offset, 1);
read_unlock(&em_tree->lock);
BUG_ON(em->start > chunk_offset ||
em->start + em->len < chunk_offset);
map = (struct map_lookup *)em->bdev;
for (i = 0; i < map->num_stripes; i++) {
ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
map->stripes[i].physical);
BUG_ON(ret);
if (map->stripes[i].dev) {
ret = btrfs_update_device(trans, map->stripes[i].dev);
BUG_ON(ret);
}
}
ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
chunk_offset);
BUG_ON(ret);
trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
BUG_ON(ret);
}
ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
BUG_ON(ret);
write_lock(&em_tree->lock);
remove_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
kfree(map);
em->bdev = NULL;
/* once for the tree */
free_extent_map(em);
/* once for us */
free_extent_map(em);
unlock_chunks(root);
btrfs_end_transaction(trans, root);
return 0;
}
static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
{
struct btrfs_root *chunk_root = root->fs_info->chunk_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_chunk *chunk;
struct btrfs_key key;
struct btrfs_key found_key;
u64 chunk_tree = chunk_root->root_key.objectid;
u64 chunk_type;
bool retried = false;
int failed = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
again:
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_CHUNK_ITEM_KEY;
while (1) {
ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
if (ret < 0)
goto error;
BUG_ON(ret == 0);
ret = btrfs_previous_item(chunk_root, path, key.objectid,
key.type);
if (ret < 0)
goto error;
if (ret > 0)
break;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
chunk = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_chunk);
chunk_type = btrfs_chunk_type(leaf, chunk);
btrfs_release_path(path);
if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
found_key.objectid,
found_key.offset);
if (ret == -ENOSPC)
failed++;
else if (ret)
BUG();
}
if (found_key.offset == 0)
break;
key.offset = found_key.offset - 1;
}
ret = 0;
if (failed && !retried) {
failed = 0;
retried = true;
goto again;
} else if (failed && retried) {
WARN_ON(1);
ret = -ENOSPC;
}
error:
btrfs_free_path(path);
return ret;
}
static u64 div_factor(u64 num, int factor)
{
if (factor == 10)
return num;
num *= factor;
do_div(num, 10);
return num;
}
int btrfs_balance(struct btrfs_root *dev_root)
{
int ret;
struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
struct btrfs_device *device;
u64 old_size;
u64 size_to_free;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
struct btrfs_trans_handle *trans;
struct btrfs_key found_key;
if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
mutex_lock(&dev_root->fs_info->volume_mutex);
dev_root = dev_root->fs_info->dev_root;
/* step one make some room on all the devices */
list_for_each_entry(device, devices, dev_list) {
old_size = device->total_bytes;
size_to_free = div_factor(old_size, 1);
size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
if (!device->writeable ||
device->total_bytes - device->bytes_used > size_to_free)
continue;
ret = btrfs_shrink_device(device, old_size - size_to_free);
if (ret == -ENOSPC)
break;
BUG_ON(ret);
trans = btrfs_start_transaction(dev_root, 0);
BUG_ON(IS_ERR(trans));
ret = btrfs_grow_device(trans, device, old_size);
BUG_ON(ret);
btrfs_end_transaction(trans, dev_root);
}
/* step two, relocate all the chunks */
path = btrfs_alloc_path();
BUG_ON(!path);
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_CHUNK_ITEM_KEY;
while (1) {
ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
if (ret < 0)
goto error;
/*
* this shouldn't happen, it means the last relocate
* failed
*/
if (ret == 0)
break;
ret = btrfs_previous_item(chunk_root, path, 0,
BTRFS_CHUNK_ITEM_KEY);
if (ret)
break;
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != key.objectid)
break;
/* chunk zero is special */
if (found_key.offset == 0)
break;
btrfs_release_path(path);
ret = btrfs_relocate_chunk(chunk_root,
chunk_root->root_key.objectid,
found_key.objectid,
found_key.offset);
if (ret && ret != -ENOSPC)
goto error;
key.offset = found_key.offset - 1;
}
ret = 0;
error:
btrfs_free_path(path);
mutex_unlock(&dev_root->fs_info->volume_mutex);
return ret;
}
/*
* shrinking a device means finding all of the device extents past
* the new size, and then following the back refs to the chunks.
* The chunk relocation code actually frees the device extent
*/
int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root = device->dev_root;
struct btrfs_dev_extent *dev_extent = NULL;
struct btrfs_path *path;
u64 length;
u64 chunk_tree;
u64 chunk_objectid;
u64 chunk_offset;
int ret;
int slot;
int failed = 0;
bool retried = false;
struct extent_buffer *l;
struct btrfs_key key;
struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
u64 old_total = btrfs_super_total_bytes(super_copy);
u64 old_size = device->total_bytes;
u64 diff = device->total_bytes - new_size;
if (new_size >= device->total_bytes)
return -EINVAL;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = 2;
lock_chunks(root);
device->total_bytes = new_size;
if (device->writeable)
device->fs_devices->total_rw_bytes -= diff;
unlock_chunks(root);
again:
key.objectid = device->devid;
key.offset = (u64)-1;
key.type = BTRFS_DEV_EXTENT_KEY;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto done;
ret = btrfs_previous_item(root, path, 0, key.type);
if (ret < 0)
goto done;
if (ret) {
ret = 0;
btrfs_release_path(path);
break;
}
l = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(l, &key, path->slots[0]);
if (key.objectid != device->devid) {
btrfs_release_path(path);
break;
}
dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
length = btrfs_dev_extent_length(l, dev_extent);
if (key.offset + length <= new_size) {
btrfs_release_path(path);
break;
}
chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
btrfs_release_path(path);
ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
chunk_offset);
if (ret && ret != -ENOSPC)
goto done;
if (ret == -ENOSPC)
failed++;
key.offset -= 1;
}
if (failed && !retried) {
failed = 0;
retried = true;
goto again;
} else if (failed && retried) {
ret = -ENOSPC;
lock_chunks(root);
device->total_bytes = old_size;
if (device->writeable)
device->fs_devices->total_rw_bytes += diff;
unlock_chunks(root);
goto done;
}
/* Shrinking succeeded, else we would be at "done". */
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto done;
}
lock_chunks(root);
device->disk_total_bytes = new_size;
/* Now btrfs_update_device() will change the on-disk size. */
ret = btrfs_update_device(trans, device);
if (ret) {
unlock_chunks(root);
btrfs_end_transaction(trans, root);
goto done;
}
WARN_ON(diff > old_total);
btrfs_set_super_total_bytes(super_copy, old_total - diff);
unlock_chunks(root);
btrfs_end_transaction(trans, root);
done:
btrfs_free_path(path);
return ret;
}
static 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;
}
/*
* sort the devices in descending order by max_avail, total_avail
*/
static int btrfs_cmp_device_info(const void *a, const void *b)
{
const struct btrfs_device_info *di_a = a;
const struct btrfs_device_info *di_b = b;
if (di_a->max_avail > di_b->max_avail)
return -1;
if (di_a->max_avail < di_b->max_avail)
return 1;
if (di_a->total_avail > di_b->total_avail)
return -1;
if (di_a->total_avail < di_b->total_avail)
return 1;
return 0;
}
static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
struct map_lookup **map_ret,
u64 *num_bytes_out, u64 *stripe_size_out,
u64 start, u64 type)
{
struct btrfs_fs_info *info = extent_root->fs_info;
struct btrfs_fs_devices *fs_devices = info->fs_devices;
struct list_head *cur;
struct map_lookup *map = NULL;
struct extent_map_tree *em_tree;
struct extent_map *em;
struct btrfs_device_info *devices_info = NULL;
u64 total_avail;
int num_stripes; /* total number of stripes to allocate */
int sub_stripes; /* sub_stripes info for map */
int dev_stripes; /* stripes per dev */
int devs_max; /* max devs to use */
int devs_min; /* min devs needed */
int devs_increment; /* ndevs has to be a multiple of this */
int ncopies; /* how many copies to data has */
int ret;
u64 max_stripe_size;
u64 max_chunk_size;
u64 stripe_size;
u64 num_bytes;
int ndevs;
int i;
int j;
if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
(type & BTRFS_BLOCK_GROUP_DUP)) {
WARN_ON(1);
type &= ~BTRFS_BLOCK_GROUP_DUP;
}
if (list_empty(&fs_devices->alloc_list))
return -ENOSPC;
sub_stripes = 1;
dev_stripes = 1;
devs_increment = 1;
ncopies = 1;
devs_max = 0; /* 0 == as many as possible */
devs_min = 1;
/*
* define the properties of each RAID type.
* FIXME: move this to a global table and use it in all RAID
* calculation code
*/
if (type & (BTRFS_BLOCK_GROUP_DUP)) {
dev_stripes = 2;
ncopies = 2;
devs_max = 1;
} else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
devs_min = 2;
} else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
devs_increment = 2;
ncopies = 2;
devs_max = 2;
devs_min = 2;
} else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
sub_stripes = 2;
devs_increment = 2;
ncopies = 2;
devs_min = 4;
} else {
devs_max = 1;
}
if (type & BTRFS_BLOCK_GROUP_DATA) {
max_stripe_size = 1024 * 1024 * 1024;
max_chunk_size = 10 * max_stripe_size;
} else if (type & BTRFS_BLOCK_GROUP_METADATA) {
max_stripe_size = 256 * 1024 * 1024;
max_chunk_size = max_stripe_size;
} else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
max_stripe_size = 8 * 1024 * 1024;
max_chunk_size = 2 * max_stripe_size;
} else {
printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
type);
BUG_ON(1);
}
/* we don't want a chunk larger than 10% of writeable space */
max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
max_chunk_size);
devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
GFP_NOFS);
if (!devices_info)
return -ENOMEM;
cur = fs_devices->alloc_list.next;
/*
* in the first pass through the devices list, we gather information
* about the available holes on each device.
*/
ndevs = 0;
while (cur != &fs_devices->alloc_list) {
struct btrfs_device *device;
u64 max_avail;
u64 dev_offset;
device = list_entry(cur, struct btrfs_device, dev_alloc_list);
cur = cur->next;
if (!device->writeable) {
printk(KERN_ERR
"btrfs: read-only device in alloc_list\n");
WARN_ON(1);
continue;
}
if (!device->in_fs_metadata)
continue;
if (device->total_bytes > device->bytes_used)
total_avail = device->total_bytes - device->bytes_used;
else
total_avail = 0;
/* avail is off by max(alloc_start, 1MB), but that is the same
* for all devices, so it doesn't hurt the sorting later on
*/
ret = find_free_dev_extent(trans, device,
max_stripe_size * dev_stripes,
&dev_offset, &max_avail);
if (ret && ret != -ENOSPC)
goto error;
if (ret == 0)
max_avail = max_stripe_size * dev_stripes;
if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
continue;
devices_info[ndevs].dev_offset = dev_offset;
devices_info[ndevs].max_avail = max_avail;
devices_info[ndevs].total_avail = total_avail;
devices_info[ndevs].dev = device;
++ndevs;
}
/*
* now sort the devices by hole size / available space
*/
sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
btrfs_cmp_device_info, NULL);
/* round down to number of usable stripes */
ndevs -= ndevs % devs_increment;
if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
ret = -ENOSPC;
goto error;
}
if (devs_max && ndevs > devs_max)
ndevs = devs_max;
/*
* the primary goal is to maximize the number of stripes, so use as many
* devices as possible, even if the stripes are not maximum sized.
*/
stripe_size = devices_info[ndevs-1].max_avail;
num_stripes = ndevs * dev_stripes;
if (stripe_size * num_stripes > max_chunk_size * ncopies) {
stripe_size = max_chunk_size * ncopies;
do_div(stripe_size, num_stripes);
}
do_div(stripe_size, dev_stripes);
do_div(stripe_size, BTRFS_STRIPE_LEN);
stripe_size *= BTRFS_STRIPE_LEN;
map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
if (!map) {
ret = -ENOMEM;
goto error;
}
map->num_stripes = num_stripes;
for (i = 0; i < ndevs; ++i) {
for (j = 0; j < dev_stripes; ++j) {
int s = i * dev_stripes + j;
map->stripes[s].dev = devices_info[i].dev;
map->stripes[s].physical = devices_info[i].dev_offset +
j * stripe_size;
}
}
map->sector_size = extent_root->sectorsize;
map->stripe_len = BTRFS_STRIPE_LEN;
map->io_align = BTRFS_STRIPE_LEN;
map->io_width = BTRFS_STRIPE_LEN;
map->type = type;
map->sub_stripes = sub_stripes;
*map_ret = map;
num_bytes = stripe_size * (num_stripes / ncopies);
*stripe_size_out = stripe_size;
*num_bytes_out = num_bytes;
trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
em = alloc_extent_map();
if (!em) {
ret = -ENOMEM;
goto error;
}
em->bdev = (struct block_device *)map;
em->start = start;
em->len = num_bytes;
em->block_start = 0;
em->block_len = em->len;
em_tree = &extent_root->fs_info->mapping_tree.map_tree;
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
BUG_ON(ret);
free_extent_map(em);
ret = btrfs_make_block_group(trans, extent_root, 0, type,
BTRFS_FIRST_CHUNK_TREE_OBJECTID,
start, num_bytes);
BUG_ON(ret);
for (i = 0; i < map->num_stripes; ++i) {
struct btrfs_device *device;
u64 dev_offset;
device = map->stripes[i].dev;
dev_offset = map->stripes[i].physical;
ret = btrfs_alloc_dev_extent(trans, device,
info->chunk_root->root_key.objectid,
BTRFS_FIRST_CHUNK_TREE_OBJECTID,
start, dev_offset, stripe_size);
BUG_ON(ret);
}
kfree(devices_info);
return 0;
error:
kfree(map);
kfree(devices_info);
return ret;
}
static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root,
struct map_lookup *map, u64 chunk_offset,
u64 chunk_size, u64 stripe_size)
{
u64 dev_offset;
struct btrfs_key key;
struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
struct btrfs_device *device;
struct btrfs_chunk *chunk;
struct btrfs_stripe *stripe;
size_t item_size = btrfs_chunk_item_size(map->num_stripes);
int index = 0;
int ret;
chunk = kzalloc(item_size, GFP_NOFS);
if (!chunk)
return -ENOMEM;
index = 0;
while (index < map->num_stripes) {
device = map->stripes[index].dev;
device->bytes_used += stripe_size;
ret = btrfs_update_device(trans, device);
BUG_ON(ret);
index++;
}
index = 0;
stripe = &chunk->stripe;
while (index < map->num_stripes) {
device = map->stripes[index].dev;
dev_offset = map->stripes[index].physical;
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);
stripe++;
index++;
}
btrfs_set_stack_chunk_length(chunk, chunk_size);
btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
btrfs_set_stack_chunk_type(chunk, map->type);
btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
key.type = BTRFS_CHUNK_ITEM_KEY;
key.offset = chunk_offset;
ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
BUG_ON(ret);
if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
item_size);
BUG_ON(ret);
}
kfree(chunk);
return 0;
}
/*
* Chunk allocation falls into two parts. The first part does works
* that make the new allocated chunk useable, but not do any operation
* that modifies the chunk tree. The second part does the works that
* require modifying the chunk tree. This division is important for the
* bootstrap process of adding storage to a seed btrfs.
*/
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 type)
{
u64 chunk_offset;
u64 chunk_size;
u64 stripe_size;
struct map_lookup *map;
struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
int ret;
ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
&chunk_offset);
if (ret)
return ret;
ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
&stripe_size, chunk_offset, type);
if (ret)
return ret;
ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
chunk_size, stripe_size);
BUG_ON(ret);
return 0;
}
static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_device *device)
{
u64 chunk_offset;
u64 sys_chunk_offset;
u64 chunk_size;
u64 sys_chunk_size;
u64 stripe_size;
u64 sys_stripe_size;
u64 alloc_profile;
struct map_lookup *map;
struct map_lookup *sys_map;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *extent_root = fs_info->extent_root;
int ret;
ret = find_next_chunk(fs_info->chunk_root,
BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
BUG_ON(ret);
alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
(fs_info->metadata_alloc_profile &
fs_info->avail_metadata_alloc_bits);
alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
&stripe_size, chunk_offset, alloc_profile);
BUG_ON(ret);
sys_chunk_offset = chunk_offset + chunk_size;
alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
(fs_info->system_alloc_profile &
fs_info->avail_system_alloc_bits);
alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
&sys_chunk_size, &sys_stripe_size,
sys_chunk_offset, alloc_profile);
BUG_ON(ret);
ret = btrfs_add_device(trans, fs_info->chunk_root, device);
BUG_ON(ret);
/*
* Modifying chunk tree needs allocating new blocks from both
* system block group and metadata block group. So we only can
* do operations require modifying the chunk tree after both
* block groups were created.
*/
ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
chunk_size, stripe_size);
BUG_ON(ret);
ret = __finish_chunk_alloc(trans, extent_root, sys_map,
sys_chunk_offset, sys_chunk_size,
sys_stripe_size);
BUG_ON(ret);
return 0;
}
int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
{
struct extent_map *em;
struct map_lookup *map;
struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
int readonly = 0;
int i;
read_lock(&map_tree->map_tree.lock);
em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
read_unlock(&map_tree->map_tree.lock);
if (!em)
return 1;
if (btrfs_test_opt(root, DEGRADED)) {
free_extent_map(em);
return 0;
}
map = (struct map_lookup *)em->bdev;
for (i = 0; i < map->num_stripes; i++) {
if (!map->stripes[i].dev->writeable) {
readonly = 1;
break;
}
}
free_extent_map(em);
return readonly;
}
void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
{
extent_map_tree_init(&tree->map_tree);
}
void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
{
struct extent_map *em;
while (1) {
write_lock(&tree->map_tree.lock);
em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
if (em)
remove_extent_mapping(&tree->map_tree, em);
write_unlock(&tree->map_tree.lock);
if (!em)
break;
kfree(em->bdev);
/* once for us */
free_extent_map(em);
/* once for the tree */
free_extent_map(em);
}
}
int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
{
struct extent_map *em;
struct map_lookup *map;
struct extent_map_tree *em_tree = &map_tree->map_tree;
int ret;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, logical, len);
read_unlock(&em_tree->lock);
BUG_ON(!em);
BUG_ON(em->start > logical || em->start + em->len < logical);
map = (struct map_lookup *)em->bdev;
if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
ret = map->num_stripes;
else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
ret = map->sub_stripes;
else
ret = 1;
free_extent_map(em);
return ret;
}
static int find_live_mirror(struct map_lookup *map, int first, int num,
int optimal)
{
int i;
if (map->stripes[optimal].dev->bdev)
return optimal;
for (i = first; i < first + num; i++) {
if (map->stripes[i].dev->bdev)
return i;
}
/* we couldn't find one that doesn't fail. Just return something
* and the io error handling code will clean up eventually
*/
return optimal;
}
static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
u64 logical, u64 *length,
struct btrfs_multi_bio **multi_ret,
int mirror_num)
{
struct extent_map *em;
struct map_lookup *map;
struct extent_map_tree *em_tree = &map_tree->map_tree;
u64 offset;
u64 stripe_offset;
u64 stripe_end_offset;
u64 stripe_nr;
u64 stripe_nr_orig;
u64 stripe_nr_end;
int stripes_allocated = 8;
int stripes_required = 1;
int stripe_index;
int i;
int num_stripes;
int max_errors = 0;
struct btrfs_multi_bio *multi = NULL;
if (multi_ret && !(rw & (REQ_WRITE | REQ_DISCARD)))
stripes_allocated = 1;
again:
if (multi_ret) {
multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
GFP_NOFS);
if (!multi)
return -ENOMEM;
atomic_set(&multi->error, 0);
}
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, logical, *length);
read_unlock(&em_tree->lock);
if (!em) {
printk(KERN_CRIT "unable to find logical %llu len %llu\n",
(unsigned long long)logical,
(unsigned long long)*length);
BUG();
}
BUG_ON(em->start > logical || em->start + em->len < logical);
map = (struct map_lookup *)em->bdev;
offset = logical - em->start;
if (mirror_num > map->num_stripes)
mirror_num = 0;
/* if our multi bio struct is too small, back off and try again */
if (rw & REQ_WRITE) {
if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_DUP)) {
stripes_required = map->num_stripes;
max_errors = 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
stripes_required = map->sub_stripes;
max_errors = 1;
}
}
if (rw & REQ_DISCARD) {
if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID10)) {
stripes_required = map->num_stripes;
}
}
if (multi_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
stripes_allocated < stripes_required) {
stripes_allocated = map->num_stripes;
free_extent_map(em);
kfree(multi);
goto again;
}
stripe_nr = offset;
/*
* stripe_nr counts the total number of stripes we have to stride
* to get to this block
*/
do_div(stripe_nr, map->stripe_len);
stripe_offset = stripe_nr * map->stripe_len;
BUG_ON(offset < stripe_offset);
/* stripe_offset is the offset of this block in its stripe*/
stripe_offset = offset - stripe_offset;
if (rw & REQ_DISCARD)
*length = min_t(u64, em->len - offset, *length);
else 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, em->len - offset,
map->stripe_len - stripe_offset);
} else {
*length = em->len - offset;
}
if (!multi_ret)
goto out;
num_stripes = 1;
stripe_index = 0;
stripe_nr_orig = stripe_nr;
stripe_nr_end = (offset + *length + map->stripe_len - 1) &
(~(map->stripe_len - 1));
do_div(stripe_nr_end, map->stripe_len);
stripe_end_offset = stripe_nr_end * map->stripe_len -
(offset + *length);
if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
if (rw & REQ_DISCARD)
num_stripes = min_t(u64, map->num_stripes,
stripe_nr_end - stripe_nr_orig);
stripe_index = do_div(stripe_nr, map->num_stripes);
} else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
if (rw & (REQ_WRITE | REQ_DISCARD))
num_stripes = map->num_stripes;
else if (mirror_num)
stripe_index = mirror_num - 1;
else {
stripe_index = find_live_mirror(map, 0,
map->num_stripes,
current->pid % map->num_stripes);
}
} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
if (rw & (REQ_WRITE | REQ_DISCARD))
num_stripes = map->num_stripes;
else if (mirror_num)
stripe_index = mirror_num - 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
int factor = map->num_stripes / map->sub_stripes;
stripe_index = do_div(stripe_nr, factor);
stripe_index *= map->sub_stripes;
if (rw & REQ_WRITE)
num_stripes = map->sub_stripes;
else if (rw & REQ_DISCARD)
num_stripes = min_t(u64, map->sub_stripes *
(stripe_nr_end - stripe_nr_orig),
map->num_stripes);
else if (mirror_num)
stripe_index += mirror_num - 1;
else {
stripe_index = find_live_mirror(map, stripe_index,
map->sub_stripes, stripe_index +
current->pid % map->sub_stripes);
}
} else {
/*
* after this do_div call, stripe_nr is the number of stripes
* on this device we have to walk to find the data, and
* stripe_index is the number of our device in the stripe array
*/
stripe_index = do_div(stripe_nr, map->num_stripes);
}
BUG_ON(stripe_index >= map->num_stripes);
if (rw & REQ_DISCARD) {
for (i = 0; i < 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;
if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
u64 stripes;
u32 last_stripe = 0;
int j;
div_u64_rem(stripe_nr_end - 1,
map->num_stripes,
&last_stripe);
for (j = 0; j < map->num_stripes; j++) {
u32 test;
div_u64_rem(stripe_nr_end - 1 - j,
map->num_stripes, &test);
if (test == stripe_index)
break;
}
stripes = stripe_nr_end - 1 - j;
do_div(stripes, map->num_stripes);
multi->stripes[i].length = map->stripe_len *
(stripes - stripe_nr + 1);
if (i == 0) {
multi->stripes[i].length -=
stripe_offset;
stripe_offset = 0;
}
if (stripe_index == last_stripe)
multi->stripes[i].length -=
stripe_end_offset;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
u64 stripes;
int j;
int factor = map->num_stripes /
map->sub_stripes;
u32 last_stripe = 0;
div_u64_rem(stripe_nr_end - 1,
factor, &last_stripe);
last_stripe *= map->sub_stripes;
for (j = 0; j < factor; j++) {
u32 test;
div_u64_rem(stripe_nr_end - 1 - j,
factor, &test);
if (test ==
stripe_index / map->sub_stripes)
break;
}
stripes = stripe_nr_end - 1 - j;
do_div(stripes, factor);
multi->stripes[i].length = map->stripe_len *
(stripes - stripe_nr + 1);
if (i < map->sub_stripes) {
multi->stripes[i].length -=
stripe_offset;
if (i == map->sub_stripes - 1)
stripe_offset = 0;
}
if (stripe_index >= last_stripe &&
stripe_index <= (last_stripe +
map->sub_stripes - 1)) {
multi->stripes[i].length -=
stripe_end_offset;
}
} else
multi->stripes[i].length = *length;
stripe_index++;
if (stripe_index == map->num_stripes) {
/* This could only happen for RAID0/10 */
stripe_index = 0;
stripe_nr++;
}
}
} else {
for (i = 0; i < num_stripes; i++) {
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++;
}
}
if (multi_ret) {
*multi_ret = multi;
multi->num_stripes = num_stripes;
multi->max_errors = max_errors;
}
out:
free_extent_map(em);
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)
{
return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
mirror_num);
}
int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
u64 chunk_start, u64 physical, u64 devid,
u64 **logical, int *naddrs, int *stripe_len)
{
struct extent_map_tree *em_tree = &map_tree->map_tree;
struct extent_map *em;
struct map_lookup *map;
u64 *buf;
u64 bytenr;
u64 length;
u64 stripe_nr;
int i, j, nr = 0;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, chunk_start, 1);
read_unlock(&em_tree->lock);
BUG_ON(!em || em->start != chunk_start);
map = (struct map_lookup *)em->bdev;
length = em->len;
if (map->type & BTRFS_BLOCK_GROUP_RAID10)
do_div(length, map->num_stripes / map->sub_stripes);
else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
do_div(length, map->num_stripes);
buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
BUG_ON(!buf);
for (i = 0; i < map->num_stripes; i++) {
if (devid && map->stripes[i].dev->devid != devid)
continue;
if (map->stripes[i].physical > physical ||
map->stripes[i].physical + length <= physical)
continue;
stripe_nr = physical - map->stripes[i].physical;
do_div(stripe_nr, map->stripe_len);
if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
stripe_nr = stripe_nr * map->num_stripes + i;
do_div(stripe_nr, map->sub_stripes);
} else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
stripe_nr = stripe_nr * map->num_stripes + i;
}
bytenr = chunk_start + stripe_nr * map->stripe_len;
WARN_ON(nr >= map->num_stripes);
for (j = 0; j < nr; j++) {
if (buf[j] == bytenr)
break;
}
if (j == nr) {
WARN_ON(nr >= map->num_stripes);
buf[nr++] = bytenr;
}
}
*logical = buf;
*naddrs = nr;
*stripe_len = map->stripe_len;
free_extent_map(em);
return 0;
}
static void end_bio_multi_stripe(struct bio *bio, int err)
{
struct btrfs_multi_bio *multi = bio->bi_private;
int is_orig_bio = 0;
if (err)
atomic_inc(&multi->error);
if (bio == multi->orig_bio)
is_orig_bio = 1;
if (atomic_dec_and_test(&multi->stripes_pending)) {
if (!is_orig_bio) {
bio_put(bio);
bio = multi->orig_bio;
}
bio->bi_private = multi->private;
bio->bi_end_io = multi->end_io;
/* only send an error to the higher layers if it is
* beyond the tolerance of the multi-bio
*/
if (atomic_read(&multi->error) > multi->max_errors) {
err = -EIO;
} else if (err) {
/*
* this bio is actually up to date, we didn't
* go over the max number of errors
*/
set_bit(BIO_UPTODATE, &bio->bi_flags);
err = 0;
}
kfree(multi);
bio_endio(bio, err);
} else if (!is_orig_bio) {
bio_put(bio);
}
}
struct async_sched {
struct bio *bio;
int rw;
struct btrfs_fs_info *info;
struct btrfs_work work;
};
/*
* see run_scheduled_bios for a description of why bios are collected for
* async submit.
*
* This will add one bio to the pending list for a device and make sure
* the work struct is scheduled.
*/
static noinline int schedule_bio(struct btrfs_root *root,
struct btrfs_device *device,
int rw, struct bio *bio)
{
int should_queue = 1;
struct btrfs_pending_bios *pending_bios;
/* don't bother with additional async steps for reads, right now */
if (!(rw & REQ_WRITE)) {
bio_get(bio);
submit_bio(rw, bio);
bio_put(bio);
return 0;
}
/*
* nr_async_bios allows us to reliably return congestion to the
* higher layers. Otherwise, the async bio makes it appear we have
* made progress against dirty pages when we've really just put it
* on a queue for later
*/
atomic_inc(&root->fs_info->nr_async_bios);
WARN_ON(bio->bi_next);
bio->bi_next = NULL;
bio->bi_rw |= rw;
spin_lock(&device->io_lock);
if (bio->bi_rw & REQ_SYNC)
pending_bios = &device->pending_sync_bios;
else
pending_bios = &device->pending_bios;
if (pending_bios->tail)
pending_bios->tail->bi_next = bio;
pending_bios->tail = bio;
if (!pending_bios->head)
pending_bios->head = bio;
if (device->running_pending)
should_queue = 0;
spin_unlock(&device->io_lock);
if (should_queue)
btrfs_queue_worker(&root->fs_info->submit_workers,
&device->work);
return 0;
}
int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
int mirror_num, int async_submit)
{
struct btrfs_mapping_tree *map_tree;
struct btrfs_device *dev;
struct bio *first_bio = bio;
u64 logical = (u64)bio->bi_sector << 9;
u64 length = 0;
u64 map_length;
struct btrfs_multi_bio *multi = NULL;
int ret;
int dev_nr = 0;
int total_devs = 1;
length = bio->bi_size;
map_tree = &root->fs_info->mapping_tree;
map_length = length;
ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
mirror_num);
BUG_ON(ret);
total_devs = multi->num_stripes;
if (map_length < length) {
printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
"len %llu\n", (unsigned long long)logical,
(unsigned long long)length,
(unsigned long long)map_length);
BUG();
}
multi->end_io = first_bio->bi_end_io;
multi->private = first_bio->bi_private;
multi->orig_bio = first_bio;
atomic_set(&multi->stripes_pending, multi->num_stripes);
while (dev_nr < total_devs) {
if (total_devs > 1) {
if (dev_nr < total_devs - 1) {
bio = bio_clone(first_bio, GFP_NOFS);
BUG_ON(!bio);
} else {
bio = first_bio;
}
bio->bi_private = multi;
bio->bi_end_io = end_bio_multi_stripe;
}
bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
dev = multi->stripes[dev_nr].dev;
if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
bio->bi_bdev = dev->bdev;
if (async_submit)
schedule_bio(root, dev, rw, bio);
else
submit_bio(rw, bio);
} else {
bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
bio->bi_sector = logical >> 9;
bio_endio(bio, -EIO);
}
dev_nr++;
}
if (total_devs == 1)
kfree(multi);
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;
}
static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
u64 devid, u8 *dev_uuid)
{
struct btrfs_device *device;
struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
device = kzalloc(sizeof(*device), GFP_NOFS);
if (!device)
return NULL;
list_add(&device->dev_list,
&fs_devices->devices);
device->dev_root = root->fs_info->dev_root;
device->devid = devid;
device->work.func = pending_bios_fn;
device->fs_devices = fs_devices;
device->missing = 1;
fs_devices->num_devices++;
fs_devices->missing_devices++;
spin_lock_init(&device->io_lock);
INIT_LIST_HEAD(&device->dev_alloc_list);
memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
return device;
}
static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
struct extent_buffer *leaf,
struct btrfs_chunk *chunk)
{
struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
struct map_lookup *map;
struct extent_map *em;
u64 logical;
u64 length;
u64 devid;
u8 uuid[BTRFS_UUID_SIZE];
int num_stripes;
int ret;
int i;
logical = key->offset;
length = btrfs_chunk_length(leaf, chunk);
read_lock(&map_tree->map_tree.lock);
em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
read_unlock(&map_tree->map_tree.lock);
/* already mapped? */
if (em && em->start <= logical && em->start + em->len > logical) {
free_extent_map(em);
return 0;
} else if (em) {
free_extent_map(em);
}
em = alloc_extent_map();
if (!em)
return -ENOMEM;
num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
if (!map) {
free_extent_map(em);
return -ENOMEM;
}
em->bdev = (struct block_device *)map;
em->start = logical;
em->len = length;
em->block_start = 0;
em->block_len = em->len;
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 && !btrfs_test_opt(root, DEGRADED)) {
kfree(map);
free_extent_map(em);
return -EIO;
}
if (!map->stripes[i].dev) {
map->stripes[i].dev =
add_missing_dev(root, devid, uuid);
if (!map->stripes[i].dev) {
kfree(map);
free_extent_map(em);
return -EIO;
}
}
map->stripes[i].dev->in_fs_metadata = 1;
}
write_lock(&map_tree->map_tree.lock);
ret = add_extent_mapping(&map_tree->map_tree, em);
write_unlock(&map_tree->map_tree.lock);
BUG_ON(ret);
free_extent_map(em);
return 0;
}
static int fill_device_from_item(struct extent_buffer *leaf,
struct btrfs_dev_item *dev_item,
struct btrfs_device *device)
{
unsigned long ptr;
device->devid = btrfs_device_id(leaf, dev_item);
device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
device->total_bytes = device->disk_total_bytes;
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;
mutex_lock(&uuid_mutex);
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;
}
fs_devices = clone_fs_devices(fs_devices);
if (IS_ERR(fs_devices)) {
ret = PTR_ERR(fs_devices);
goto out;
}
ret = __btrfs_open_devices(fs_devices, FMODE_READ,
root->fs_info->bdev_holder);
if (ret)
goto out;
if (!fs_devices->seeding) {
__btrfs_close_devices(fs_devices);
free_fs_devices(fs_devices);
ret = -EINVAL;
goto out;
}
fs_devices->seed = root->fs_info->fs_devices->seed;
root->fs_info->fs_devices->seed = fs_devices;
out:
mutex_unlock(&uuid_mutex);
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;
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 && !btrfs_test_opt(root, DEGRADED))
return ret;
}
device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
if (!device || !device->bdev) {
if (!btrfs_test_opt(root, DEGRADED))
return -EIO;
if (!device) {
printk(KERN_WARNING "warning devid %llu missing\n",
(unsigned long long)devid);
device = add_missing_dev(root, devid, dev_uuid);
if (!device)
return -ENOMEM;
} else if (!device->missing) {
/*
* this happens when a device that was properly setup
* in the device info lists suddenly goes bad.
* device->bdev is NULL, and so we have to set
* device->missing to one here
*/
root->fs_info->fs_devices->missing_devices++;
device->missing = 1;
}
}
if (device->fs_devices != root->fs_info->fs_devices) {
BUG_ON(device->writeable);
if (device->generation !=
btrfs_device_generation(leaf, dev_item))
return -EINVAL;
}
fill_device_from_item(leaf, dev_item, device);
device->dev_root = root->fs_info->dev_root;
device->in_fs_metadata = 1;
if (device->writeable)
device->fs_devices->total_rw_bytes += device->total_bytes;
ret = 0;
return ret;
}
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;
u8 *ptr;
unsigned long sb_ptr;
int ret = 0;
u32 num_stripes;
u32 array_size;
u32 len = 0;
u32 cur;
struct btrfs_key key;
sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
BTRFS_SUPER_INFO_SIZE);
if (!sb)
return -ENOMEM;
btrfs_set_buffer_uptodate(sb);
btrfs_set_buffer_lockdep_class(sb, 0);
write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
array_size = btrfs_super_sys_array_size(super_copy);
ptr = super_copy->sys_chunk_array;
sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
cur = 0;
while (cur < array_size) {
disk_key = (struct btrfs_disk_key *)ptr;
btrfs_disk_key_to_cpu(&key, disk_key);
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);
if (ret)
break;
num_stripes = btrfs_chunk_num_stripes(sb, chunk);
len = btrfs_chunk_item_size(num_stripes);
} else {
ret = -EIO;
break;
}
ptr += len;
sb_ptr += len;
cur += len;
}
free_extent_buffer(sb);
return ret;
}
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);
if (ret < 0)
goto error;
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);
if (ret)
goto error;
}
} 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);
if (ret)
goto error;
}
path->slots[0]++;
}
if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
key.objectid = 0;
btrfs_release_path(path);
goto again;
}
ret = 0;
error:
btrfs_free_path(path);
return ret;
}