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cfa4c961cc
linux-next/fs/btrfs/volumes.c
Ilya Dryomov cfa4c961cc Btrfs: soft profile changing mode (aka soft convert) 
When doing convert from one profile to another if soft mode is on
restriper won't touch chunks that already have the profile we are
converting to.  This is useful if e.g. half of the FS was converted
earlier.

The soft mode switch is (like every other filter) per-type.  This means
that we can convert for example meta chunks the "hard" way while
converting data chunks selectively with soft switch.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16 22:04:48 +02:00

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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/sched.h>
#include <linux/bio.h>
#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;
int sync_pending = 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);
/*
* if we're doing the sync list, record that our
* plug has some sync requests on it
*
* If we're doing the regular list and there are
* sync requests sitting around, unplug before
* we add more
*/
if (pending_bios == &device->pending_sync_bios) {
sync_pending = 1;
} else if (sync_pending) {
blk_finish_plug(&plug);
blk_start_plug(&plug);
sync_pending = 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;
}
/* unplug every 64 requests just for good measure */
if (batch_run % 64 == 0) {
blk_finish_plug(&plug);
blk_start_plug(&plug);
sync_pending = 0;
}
}
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);
/* init readahead state */
spin_lock_init(&device->reada_lock);
device->reada_curr_zone = NULL;
atomic_set(&device->reada_in_flight, 0);
device->reada_next = 0;
INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
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;
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);
}
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)
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 = -EINVAL;
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;
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();
}
/*
* At this point, search_start should be the end of
* allocated dev extents, and when shrinking the device,
* search_end may be smaller than search_start.
*/
if (search_end > search_start)
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;
again:
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);
key = found_key;
btrfs_release_path(path);
goto again;
} 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) {
u64 len = btrfs_dev_extent_length(leaf, extent);
device->bytes_used -= len;
spin_lock(&root->fs_info->free_chunk_lock);
root->fs_info->free_chunk_space += len;
spin_unlock(&root->fs_info->free_chunk_lock);
}
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();
if (!path)
return -ENOMEM;
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);
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;
spin_lock(&root->fs_info->free_chunk_lock);
root->fs_info->free_chunk_space = device->total_bytes -
device->bytes_used;
spin_unlock(&root->fs_info->free_chunk_lock);
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(&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_WRITE | 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);
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;
spin_lock(&root->fs_info->free_chunk_lock);
root->fs_info->free_chunk_space += device->total_bytes;
spin_unlock(&root->fs_info->free_chunk_lock);
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);
}
return ret;
error:
blkdev_put(bdev, FMODE_EXCL);
if (seeding_dev) {
mutex_unlock(&uuid_mutex);
up_write(&sb->s_umount);
}
return ret;
}
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;
}
/*
* Should be called with both balance and volume mutexes held to
* serialize other volume operations (add_dev/rm_dev/resize) with
* restriper. Same goes for unset_balance_control.
*/
static void set_balance_control(struct btrfs_balance_control *bctl)
{
struct btrfs_fs_info *fs_info = bctl->fs_info;
BUG_ON(fs_info->balance_ctl);
spin_lock(&fs_info->balance_lock);
fs_info->balance_ctl = bctl;
spin_unlock(&fs_info->balance_lock);
}
static void unset_balance_control(struct btrfs_fs_info *fs_info)
{
struct btrfs_balance_control *bctl = fs_info->balance_ctl;
BUG_ON(!fs_info->balance_ctl);
spin_lock(&fs_info->balance_lock);
fs_info->balance_ctl = NULL;
spin_unlock(&fs_info->balance_lock);
kfree(bctl);
}
/*
* Balance filters. Return 1 if chunk should be filtered out
* (should not be balanced).
*/
static int chunk_profiles_filter(u64 chunk_profile,
struct btrfs_balance_args *bargs)
{
chunk_profile &= BTRFS_BLOCK_GROUP_PROFILE_MASK;
if (chunk_profile == 0)
chunk_profile = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
if (bargs->profiles & chunk_profile)
return 0;
return 1;
}
static u64 div_factor_fine(u64 num, int factor)
{
if (factor <= 0)
return 0;
if (factor >= 100)
return num;
num *= factor;
do_div(num, 100);
return num;
}
static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
struct btrfs_balance_args *bargs)
{
struct btrfs_block_group_cache *cache;
u64 chunk_used, user_thresh;
int ret = 1;
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_used = btrfs_block_group_used(&cache->item);
user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
if (chunk_used < user_thresh)
ret = 0;
btrfs_put_block_group(cache);
return ret;
}
static int chunk_devid_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
struct btrfs_balance_args *bargs)
{
struct btrfs_stripe *stripe;
int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
int i;
for (i = 0; i < num_stripes; i++) {
stripe = btrfs_stripe_nr(chunk, i);
if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
return 0;
}
return 1;
}
/* [pstart, pend) */
static int chunk_drange_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
u64 chunk_offset,
struct btrfs_balance_args *bargs)
{
struct btrfs_stripe *stripe;
int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
u64 stripe_offset;
u64 stripe_length;
int factor;
int i;
if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
return 0;
if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
factor = 2;
else
factor = 1;
factor = num_stripes / factor;
for (i = 0; i < num_stripes; i++) {
stripe = btrfs_stripe_nr(chunk, i);
if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
continue;
stripe_offset = btrfs_stripe_offset(leaf, stripe);
stripe_length = btrfs_chunk_length(leaf, chunk);
do_div(stripe_length, factor);
if (stripe_offset < bargs->pend &&
stripe_offset + stripe_length > bargs->pstart)
return 0;
}
return 1;
}
/* [vstart, vend) */
static int chunk_vrange_filter(struct extent_buffer *leaf,
struct btrfs_chunk *chunk,
u64 chunk_offset,
struct btrfs_balance_args *bargs)
{
if (chunk_offset < bargs->vend &&
chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
/* at least part of the chunk is inside this vrange */
return 0;
return 1;
}
static int chunk_soft_convert_filter(u64 chunk_profile,
struct btrfs_balance_args *bargs)
{
if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
return 0;
chunk_profile &= BTRFS_BLOCK_GROUP_PROFILE_MASK;
if (chunk_profile == 0)
chunk_profile = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
if (bargs->target & chunk_profile)
return 1;
return 0;
}
static int should_balance_chunk(struct btrfs_root *root,
struct extent_buffer *leaf,
struct btrfs_chunk *chunk, u64 chunk_offset)
{
struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
struct btrfs_balance_args *bargs = NULL;
u64 chunk_type = btrfs_chunk_type(leaf, chunk);
/* type filter */
if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
(bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
return 0;
}
if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
bargs = &bctl->data;
else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
bargs = &bctl->sys;
else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
bargs = &bctl->meta;
/* profiles filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
chunk_profiles_filter(chunk_type, bargs)) {
return 0;
}
/* usage filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
return 0;
}
/* devid filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
chunk_devid_filter(leaf, chunk, bargs)) {
return 0;
}
/* drange filter, makes sense only with devid filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
return 0;
}
/* vrange filter */
if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
return 0;
}
/* soft profile changing mode */
if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
chunk_soft_convert_filter(chunk_type, bargs)) {
return 0;
}
return 1;
}
static u64 div_factor(u64 num, int factor)
{
if (factor == 10)
return num;
num *= factor;
do_div(num, 10);
return num;
}
static int __btrfs_balance(struct btrfs_fs_info *fs_info)
{
struct btrfs_root *chunk_root = fs_info->chunk_root;
struct btrfs_root *dev_root = fs_info->dev_root;
struct list_head *devices;
struct btrfs_device *device;
u64 old_size;
u64 size_to_free;
struct btrfs_chunk *chunk;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_trans_handle *trans;
struct extent_buffer *leaf;
int slot;
int ret;
int enospc_errors = 0;
/* step one make some room on all the devices */
devices = &fs_info->fs_devices->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();
if (!path) {
ret = -ENOMEM;
goto error;
}
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)
BUG(); /* FIXME break ? */
ret = btrfs_previous_item(chunk_root, path, 0,
BTRFS_CHUNK_ITEM_KEY);
if (ret) {
ret = 0;
break;
}
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != key.objectid)
break;
/* chunk zero is special */
if (found_key.offset == 0)
break;
chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
ret = should_balance_chunk(chunk_root, leaf, chunk,
found_key.offset);
btrfs_release_path(path);
if (!ret)
goto loop;
ret = btrfs_relocate_chunk(chunk_root,
chunk_root->root_key.objectid,
found_key.objectid,
found_key.offset);
if (ret && ret != -ENOSPC)
goto error;
if (ret == -ENOSPC)
enospc_errors++;
loop:
key.offset = found_key.offset - 1;
}
error:
btrfs_free_path(path);
if (enospc_errors) {
printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
enospc_errors);
if (!ret)
ret = -ENOSPC;
}
return ret;
}
static void __cancel_balance(struct btrfs_fs_info *fs_info)
{
unset_balance_control(fs_info);
}
void update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
struct btrfs_ioctl_balance_args *bargs);
/*
* Should be called with both balance and volume mutexes held
*/
int btrfs_balance(struct btrfs_balance_control *bctl,
struct btrfs_ioctl_balance_args *bargs)
{
struct btrfs_fs_info *fs_info = bctl->fs_info;
u64 allowed;
int ret;
if (btrfs_fs_closing(fs_info)) {
ret = -EINVAL;
goto out;
}
/*
* In case of mixed groups both data and meta should be picked,
* and identical options should be given for both of them.
*/
allowed = btrfs_super_incompat_flags(fs_info->super_copy);
if ((allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
(bctl->flags & (BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA))) {
if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
!(bctl->flags & BTRFS_BALANCE_METADATA) ||
memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
printk(KERN_ERR "btrfs: with mixed groups data and "
"metadata balance options must be the same\n");
ret = -EINVAL;
goto out;
}
}
/*
* Profile changing sanity checks. Skip them if a simple
* balance is requested.
*/
if (!((bctl->data.flags | bctl->sys.flags | bctl->meta.flags) &
BTRFS_BALANCE_ARGS_CONVERT))
goto do_balance;
allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
if (fs_info->fs_devices->num_devices == 1)
allowed |= BTRFS_BLOCK_GROUP_DUP;
else if (fs_info->fs_devices->num_devices < 4)
allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
else
allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10);
if (!profile_is_valid(bctl->data.target, 1) ||
bctl->data.target & ~allowed) {
printk(KERN_ERR "btrfs: unable to start balance with target "
"data profile %llu\n",
(unsigned long long)bctl->data.target);
ret = -EINVAL;
goto out;
}
if (!profile_is_valid(bctl->meta.target, 1) ||
bctl->meta.target & ~allowed) {
printk(KERN_ERR "btrfs: unable to start balance with target "
"metadata profile %llu\n",
(unsigned long long)bctl->meta.target);
ret = -EINVAL;
goto out;
}
if (!profile_is_valid(bctl->sys.target, 1) ||
bctl->sys.target & ~allowed) {
printk(KERN_ERR "btrfs: unable to start balance with target "
"system profile %llu\n",
(unsigned long long)bctl->sys.target);
ret = -EINVAL;
goto out;
}
if (bctl->data.target & BTRFS_BLOCK_GROUP_DUP) {
printk(KERN_ERR "btrfs: dup for data is not allowed\n");
ret = -EINVAL;
goto out;
}
/* allow to reduce meta or sys integrity only if force set */
allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_RAID10;
if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
(fs_info->avail_system_alloc_bits & allowed) &&
!(bctl->sys.target & allowed)) ||
((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
(fs_info->avail_metadata_alloc_bits & allowed) &&
!(bctl->meta.target & allowed))) {
if (bctl->flags & BTRFS_BALANCE_FORCE) {
printk(KERN_INFO "btrfs: force reducing metadata "
"integrity\n");
} else {
printk(KERN_ERR "btrfs: balance will reduce metadata "
"integrity, use force if you want this\n");
ret = -EINVAL;
goto out;
}
}
do_balance:
set_balance_control(bctl);
mutex_unlock(&fs_info->balance_mutex);
ret = __btrfs_balance(fs_info);
mutex_lock(&fs_info->balance_mutex);
if (bargs) {
memset(bargs, 0, sizeof(*bargs));
update_ioctl_balance_args(fs_info, bargs);
}
__cancel_balance(fs_info);
return ret;
out:
kfree(bctl);
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;
spin_lock(&root->fs_info->free_chunk_lock);
root->fs_info->free_chunk_space -= diff;
spin_unlock(&root->fs_info->free_chunk_lock);
}
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;
spin_lock(&root->fs_info->free_chunk_lock);
root->fs_info->free_chunk_space += diff;
spin_unlock(&root->fs_info->free_chunk_lock);
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;
/* If there is no space on this device, skip it. */
if (total_avail == 0)
continue;
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++;
}
spin_lock(&extent_root->fs_info->free_chunk_lock);
extent_root->fs_info->free_chunk_space -= (stripe_size *
map->num_stripes);
spin_unlock(&extent_root->fs_info->free_chunk_lock);
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);
if (ret)
return ret;
alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
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->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_bio **bbio_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_bio *bbio = NULL;
if (bbio_ret && !(rw & (REQ_WRITE | REQ_DISCARD)))
stripes_allocated = 1;
again:
if (bbio_ret) {
bbio = kzalloc(btrfs_bio_size(stripes_allocated),
GFP_NOFS);
if (!bbio)
return -ENOMEM;
atomic_set(&bbio->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 btrfs_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_PROFILE_MASK)
stripes_required = map->num_stripes;
}
if (bbio_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
stripes_allocated < stripes_required) {
stripes_allocated = map->num_stripes;
free_extent_map(em);
kfree(bbio);
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_PROFILE_MASK) {
/* 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 (!bbio_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);
mirror_num = stripe_index + 1;
}
} 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 {
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);
mirror_num = stripe_index + 1;
}
} else {
/*
* after this do_div call, stripe_nr is the number of stripes
* on this device we have to walk to find the data, and
* stripe_index is the number of our device in the stripe array
*/
stripe_index = do_div(stripe_nr, map->num_stripes);
mirror_num = stripe_index + 1;
}
BUG_ON(stripe_index >= map->num_stripes);
if (rw & REQ_DISCARD) {
for (i = 0; i < num_stripes; i++) {
bbio->stripes[i].physical =
map->stripes[stripe_index].physical +
stripe_offset + stripe_nr * map->stripe_len;
bbio->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);
bbio->stripes[i].length = map->stripe_len *
(stripes - stripe_nr + 1);
if (i == 0) {
bbio->stripes[i].length -=
stripe_offset;
stripe_offset = 0;
}
if (stripe_index == last_stripe)
bbio->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);
bbio->stripes[i].length = map->stripe_len *
(stripes - stripe_nr + 1);
if (i < map->sub_stripes) {
bbio->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)) {
bbio->stripes[i].length -=
stripe_end_offset;
}
} else
bbio->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++) {
bbio->stripes[i].physical =
map->stripes[stripe_index].physical +
stripe_offset +
stripe_nr * map->stripe_len;
bbio->stripes[i].dev =
map->stripes[stripe_index].dev;
stripe_index++;
}
}
if (bbio_ret) {
*bbio_ret = bbio;
bbio->num_stripes = num_stripes;
bbio->max_errors = max_errors;
bbio->mirror_num = mirror_num;
}
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_bio **bbio_ret, int mirror_num)
{
return __btrfs_map_block(map_tree, rw, logical, length, bbio_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 btrfs_end_bio(struct bio *bio, int err)
{
struct btrfs_bio *bbio = bio->bi_private;
int is_orig_bio = 0;
if (err)
atomic_inc(&bbio->error);
if (bio == bbio->orig_bio)
is_orig_bio = 1;
if (atomic_dec_and_test(&bbio->stripes_pending)) {
if (!is_orig_bio) {
bio_put(bio);
bio = bbio->orig_bio;
}
bio->bi_private = bbio->private;
bio->bi_end_io = bbio->end_io;
bio->bi_bdev = (struct block_device *)
(unsigned long)bbio->mirror_num;
/* only send an error to the higher layers if it is
* beyond the tolerance of the multi-bio
*/
if (atomic_read(&bbio->error) > bbio->max_errors) {
err = -EIO;
} else {
/*
* 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(bbio);
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;
int ret;
int dev_nr = 0;
int total_devs = 1;
struct btrfs_bio *bbio = NULL;
length = bio->bi_size;
map_tree = &root->fs_info->mapping_tree;
map_length = length;
ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
mirror_num);
BUG_ON(ret);
total_devs = bbio->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();
}
bbio->orig_bio = first_bio;
bbio->private = first_bio->bi_private;
bbio->end_io = first_bio->bi_end_io;
atomic_set(&bbio->stripes_pending, bbio->num_stripes);
while (dev_nr < total_devs) {
if (dev_nr < total_devs - 1) {
bio = bio_clone(first_bio, GFP_NOFS);
BUG_ON(!bio);
} else {
bio = first_bio;
}
bio->bi_private = bbio;
bio->bi_end_io = btrfs_end_bio;
bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
dev = bbio->stripes[dev_nr].dev;
if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
"(%s id %llu), size=%u\n", rw,
(u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
dev->name, dev->devid, bio->bi_size);
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++;
}
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;
spin_lock(&root->fs_info->free_chunk_lock);
root->fs_info->free_chunk_space += device->total_bytes -
device->bytes_used;
spin_unlock(&root->fs_info->free_chunk_lock);
}
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(root->root_key.objectid, 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;
}
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