[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/btrfs/volumes.c b/ap/os/linux/linux-3.4.x/fs/btrfs/volumes.c
new file mode 100644
index 0000000..d5dc63c
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/btrfs/volumes.c
@@ -0,0 +1,4593 @@
+/*
+ * 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 <linux/kthread.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"
+#include "check-integrity.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);
+}
+
+void 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);
+ }
+}
+
+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 void 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;
+ }
+
+ btrfsic_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);
+}
+
+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);
+}
+
+void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
+{
+ struct btrfs_device *device, *next;
+
+ struct block_device *latest_bdev = NULL;
+ u64 latest_devid = 0;
+ u64 latest_transid = 0;
+
+ 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) {
+ if (!latest_transid ||
+ device->generation > latest_transid) {
+ latest_devid = device->devid;
+ latest_transid = device->generation;
+ latest_bdev = device->bdev;
+ }
+ 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;
+ }
+
+ fs_devices->latest_bdev = latest_bdev;
+ fs_devices->latest_devid = latest_devid;
+ fs_devices->latest_trans = latest_transid;
+
+ mutex_unlock(&uuid_mutex);
+}
+
+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); /* -ENOMEM */
+ memcpy(new_device, device, sizeof(*new_device));
+ new_device->name = kstrdup(device->name, GFP_NOFS);
+ BUG_ON(device->name && !new_device->name); /* -ENOMEM */
+ new_device->bdev = NULL;
+ new_device->writeable = 0;
+ new_device->in_fs_metadata = 0;
+ new_device->can_discard = 0;
+ spin_lock_init(&new_device->io_lock);
+ list_replace_rcu(&device->dev_list, &new_device->dev_list);
+
+ call_rcu(&device->rcu, free_device);
+ }
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ WARN_ON(fs_devices->open_devices);
+ WARN_ON(fs_devices->rw_devices);
+ fs_devices->opened = 0;
+ fs_devices->seeding = 0;
+
+ return 0;
+}
+
+int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
+{
+ struct btrfs_fs_devices *seed_devices = NULL;
+ int ret;
+
+ mutex_lock(&uuid_mutex);
+ ret = __btrfs_close_devices(fs_devices);
+ if (!fs_devices->opened) {
+ seed_devices = fs_devices->seed;
+ fs_devices->seed = NULL;
+ }
+ mutex_unlock(&uuid_mutex);
+
+ while (seed_devices) {
+ fs_devices = seed_devices;
+ seed_devices = fs_devices->seed;
+ __btrfs_close_devices(fs_devices);
+ free_fs_devices(fs_devices);
+ }
+ /*
+ * Wait for rcu kworkers under __btrfs_close_devices
+ * to finish all blkdev_puts so device is really
+ * free when umount is done.
+ */
+ rcu_barrier();
+ return ret;
+}
+
+static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
+ fmode_t flags, void *holder)
+{
+ struct request_queue *q;
+ struct block_device *bdev;
+ struct list_head *head = &fs_devices->devices;
+ struct btrfs_device *device;
+ struct block_device *latest_bdev = NULL;
+ struct buffer_head *bh;
+ struct btrfs_super_block *disk_super;
+ u64 latest_devid = 0;
+ u64 latest_transid = 0;
+ u64 devid;
+ int seeding = 1;
+ int ret = 0;
+
+ flags |= FMODE_EXCL;
+
+ list_for_each_entry(device, head, dev_list) {
+ if (device->bdev)
+ continue;
+ if (!device->name)
+ continue;
+
+ bdev = blkdev_get_by_path(device->name, flags, holder);
+ if (IS_ERR(bdev)) {
+ printk(KERN_INFO "open %s failed\n", device->name);
+ goto error;
+ }
+ filemap_write_and_wait(bdev->bd_inode->i_mapping);
+ invalidate_bdev(bdev);
+ 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;
+
+ flags |= FMODE_EXCL;
+ bdev = blkdev_get_by_path(path, flags, holder);
+
+ if (IS_ERR(bdev)) {
+ ret = PTR_ERR(bdev);
+ goto error;
+ }
+
+ mutex_lock(&uuid_mutex);
+ 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:
+ mutex_unlock(&uuid_mutex);
+ blkdev_put(bdev, flags);
+error:
+ 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
+ * @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_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(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;
+
+ 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);
+ } else {
+ btrfs_error(root->fs_info, ret, "Slot search failed");
+ goto out;
+ }
+
+ 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);
+ if (ret) {
+ btrfs_error(root->fs_info, ret,
+ "Failed to remove dev extent item");
+ }
+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));
+ if (ret)
+ goto out;
+
+ 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);
+out:
+ 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); /* Corruption */
+
+ 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); /* Corruption */
+
+ 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);
+ invalidate_bdev(bdev);
+ 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) {
+ fs_devices->seed = cur_devices->seed;
+ break;
+ }
+ fs_devices = fs_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_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); /* Logic error */
+
+ 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(root);
+ BUG_ON(ret); /* -ENOMEM */
+ }
+
+ 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);
+ if (ret)
+ goto error_trans;
+ ret = btrfs_finish_sprout(trans, root);
+ if (ret)
+ goto error_trans;
+ } else {
+ ret = btrfs_add_device(trans, root, device);
+ if (ret)
+ goto error_trans;
+ }
+
+ /*
+ * we've got more storage, clear any full flags on the space
+ * infos
+ */
+ btrfs_clear_space_info_full(root->fs_info);
+
+ unlock_chunks(root);
+ ret = btrfs_commit_transaction(trans, root);
+
+ if (seeding_dev) {
+ mutex_unlock(&uuid_mutex);
+ up_write(&sb->s_umount);
+
+ if (ret) /* transaction commit */
+ return ret;
+
+ ret = btrfs_relocate_sys_chunks(root);
+ if (ret < 0)
+ btrfs_error(root->fs_info, ret,
+ "Failed to relocate sys chunks after "
+ "device initialization. This can be fixed "
+ "using the \"btrfs balance\" command.");
+ }
+
+ return ret;
+
+error_trans:
+ unlock_chunks(root);
+ btrfs_abort_transaction(trans, root, ret);
+ btrfs_end_transaction(trans, root);
+ kfree(device->name);
+ kfree(device);
+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);
+ if (ret < 0)
+ goto out;
+ else if (ret > 0) { /* Logic error or corruption */
+ btrfs_error(root->fs_info, -ENOENT,
+ "Failed lookup while freeing chunk.");
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = btrfs_del_item(trans, root, path);
+ if (ret < 0)
+ btrfs_error(root->fs_info, ret,
+ "Failed to delete chunk item.");
+out:
+ 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 || 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); /* Corruption */
+
+ ret = btrfs_previous_item(chunk_root, path, key.objectid,
+ key.type);
+ if (ret < 0)
+ goto error;
+ if (ret > 0)
+ break;
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+ chunk = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_chunk);
+ chunk_type = btrfs_chunk_type(leaf, chunk);
+ btrfs_release_path(path);
+
+ if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
+ found_key.objectid,
+ found_key.offset);
+ if (ret == -ENOSPC)
+ failed++;
+ else if (ret)
+ BUG();
+ }
+
+ if (found_key.offset == 0)
+ break;
+ key.offset = found_key.offset - 1;
+ }
+ ret = 0;
+ if (failed && !retried) {
+ failed = 0;
+ retried = true;
+ goto again;
+ } else if (failed && retried) {
+ WARN_ON(1);
+ ret = -ENOSPC;
+ }
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int insert_balance_item(struct btrfs_root *root,
+ struct btrfs_balance_control *bctl)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_balance_item *item;
+ struct btrfs_disk_balance_args disk_bargs;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ int ret, err;
+
+ 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_BALANCE_OBJECTID;
+ key.type = BTRFS_BALANCE_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &key,
+ sizeof(*item));
+ if (ret)
+ goto out;
+
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
+
+ memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
+
+ btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
+ btrfs_set_balance_data(leaf, item, &disk_bargs);
+ btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
+ btrfs_set_balance_meta(leaf, item, &disk_bargs);
+ btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
+ btrfs_set_balance_sys(leaf, item, &disk_bargs);
+
+ btrfs_set_balance_flags(leaf, item, bctl->flags);
+
+ btrfs_mark_buffer_dirty(leaf);
+out:
+ btrfs_free_path(path);
+ err = btrfs_commit_transaction(trans, root);
+ if (err && !ret)
+ ret = err;
+ return ret;
+}
+
+static int del_balance_item(struct btrfs_root *root)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ int ret, err;
+
+ 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_BALANCE_OBJECTID;
+ key.type = BTRFS_BALANCE_ITEM_KEY;
+ key.offset = 0;
+
+ 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);
+out:
+ btrfs_free_path(path);
+ err = btrfs_commit_transaction(trans, root);
+ if (err && !ret)
+ ret = err;
+ return ret;
+}
+
+/*
+ * This is a heuristic used to reduce the number of chunks balanced on
+ * resume after balance was interrupted.
+ */
+static void update_balance_args(struct btrfs_balance_control *bctl)
+{
+ /*
+ * Turn on soft mode for chunk types that were being converted.
+ */
+ if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
+ bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
+ if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
+ bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
+ if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
+ bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
+
+ /*
+ * Turn on usage filter if is not already used. The idea is
+ * that chunks that we have already balanced should be
+ * reasonably full. Don't do it for chunks that are being
+ * converted - that will keep us from relocating unconverted
+ * (albeit full) chunks.
+ */
+ if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+ !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
+ bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
+ bctl->data.usage = 90;
+ }
+ if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+ !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
+ bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
+ bctl->sys.usage = 90;
+ }
+ if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+ !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
+ bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
+ bctl->meta.usage = 90;
+ }
+}
+
+/*
+ * 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_type,
+ struct btrfs_balance_args *bargs)
+{
+ chunk_type = chunk_to_extended(chunk_type) &
+ BTRFS_EXTENDED_PROFILE_MASK;
+
+ if (bargs->profiles & chunk_type)
+ 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_type,
+ struct btrfs_balance_args *bargs)
+{
+ if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
+ return 0;
+
+ chunk_type = chunk_to_extended(chunk_type) &
+ BTRFS_EXTENDED_PROFILE_MASK;
+
+ if (bargs->target == chunk_type)
+ 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_balance_control *bctl = fs_info->balance_ctl;
+ 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;
+ bool counting = true;
+
+ /* 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;
+ }
+
+ /* zero out stat counters */
+ spin_lock(&fs_info->balance_lock);
+ memset(&bctl->stat, 0, sizeof(bctl->stat));
+ spin_unlock(&fs_info->balance_lock);
+again:
+ key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+ key.offset = (u64)-1;
+ key.type = BTRFS_CHUNK_ITEM_KEY;
+
+ while (1) {
+ if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
+ atomic_read(&fs_info->balance_cancel_req)) {
+ ret = -ECANCELED;
+ goto error;
+ }
+
+ 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);
+
+ if (!counting) {
+ spin_lock(&fs_info->balance_lock);
+ bctl->stat.considered++;
+ spin_unlock(&fs_info->balance_lock);
+ }
+
+ ret = should_balance_chunk(chunk_root, leaf, chunk,
+ found_key.offset);
+ btrfs_release_path(path);
+ if (!ret)
+ goto loop;
+
+ if (counting) {
+ spin_lock(&fs_info->balance_lock);
+ bctl->stat.expected++;
+ spin_unlock(&fs_info->balance_lock);
+ 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++;
+ } else {
+ spin_lock(&fs_info->balance_lock);
+ bctl->stat.completed++;
+ spin_unlock(&fs_info->balance_lock);
+ }
+loop:
+ key.offset = found_key.offset - 1;
+ }
+
+ if (counting) {
+ btrfs_release_path(path);
+ counting = false;
+ goto again;
+ }
+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;
+}
+
+/**
+ * alloc_profile_is_valid - see if a given profile is valid and reduced
+ * @flags: profile to validate
+ * @extended: if true @flags is treated as an extended profile
+ */
+static int alloc_profile_is_valid(u64 flags, int extended)
+{
+ u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
+ BTRFS_BLOCK_GROUP_PROFILE_MASK);
+
+ flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
+
+ /* 1) check that all other bits are zeroed */
+ if (flags & ~mask)
+ return 0;
+
+ /* 2) see if profile is reduced */
+ if (flags == 0)
+ return !extended; /* "0" is valid for usual profiles */
+
+ /* true if exactly one bit set */
+ return (flags & (flags - 1)) == 0;
+}
+
+static inline int balance_need_close(struct btrfs_fs_info *fs_info)
+{
+ /* cancel requested || normal exit path */
+ return atomic_read(&fs_info->balance_cancel_req) ||
+ (atomic_read(&fs_info->balance_pause_req) == 0 &&
+ atomic_read(&fs_info->balance_cancel_req) == 0);
+}
+
+static void __cancel_balance(struct btrfs_fs_info *fs_info)
+{
+ int ret;
+
+ unset_balance_control(fs_info);
+ ret = del_balance_item(fs_info->tree_root);
+ BUG_ON(ret);
+}
+
+void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
+ 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 mixed = 0;
+ int ret;
+
+ if (btrfs_fs_closing(fs_info) ||
+ atomic_read(&fs_info->balance_pause_req) ||
+ atomic_read(&fs_info->balance_cancel_req)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ allowed = btrfs_super_incompat_flags(fs_info->super_copy);
+ if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
+ mixed = 1;
+
+ /*
+ * In case of mixed groups both data and meta should be picked,
+ * and identical options should be given for both of them.
+ */
+ allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
+ if (mixed && (bctl->flags & allowed)) {
+ 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;
+ }
+ }
+
+ 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 ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (!alloc_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 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (!alloc_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 ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (!alloc_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;
+ }
+
+ /* allow dup'ed data chunks only in mixed mode */
+ if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
+ (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;
+ }
+ }
+
+ ret = insert_balance_item(fs_info->tree_root, bctl);
+ if (ret && ret != -EEXIST)
+ goto out;
+
+ if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
+ BUG_ON(ret == -EEXIST);
+ set_balance_control(bctl);
+ } else {
+ BUG_ON(ret != -EEXIST);
+ spin_lock(&fs_info->balance_lock);
+ update_balance_args(bctl);
+ spin_unlock(&fs_info->balance_lock);
+ }
+
+ atomic_inc(&fs_info->balance_running);
+ mutex_unlock(&fs_info->balance_mutex);
+
+ ret = __btrfs_balance(fs_info);
+
+ mutex_lock(&fs_info->balance_mutex);
+ atomic_dec(&fs_info->balance_running);
+
+ if (bargs) {
+ memset(bargs, 0, sizeof(*bargs));
+ update_ioctl_balance_args(fs_info, 0, bargs);
+ }
+
+ if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
+ balance_need_close(fs_info)) {
+ __cancel_balance(fs_info);
+ }
+
+ wake_up(&fs_info->balance_wait_q);
+
+ return ret;
+out:
+ if (bctl->flags & BTRFS_BALANCE_RESUME)
+ __cancel_balance(fs_info);
+ else
+ kfree(bctl);
+ return ret;
+}
+
+static int balance_kthread(void *data)
+{
+ struct btrfs_balance_control *bctl =
+ (struct btrfs_balance_control *)data;
+ struct btrfs_fs_info *fs_info = bctl->fs_info;
+ int ret = 0;
+
+ mutex_lock(&fs_info->volume_mutex);
+ mutex_lock(&fs_info->balance_mutex);
+
+ set_balance_control(bctl);
+
+ if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
+ printk(KERN_INFO "btrfs: force skipping balance\n");
+ } else {
+ printk(KERN_INFO "btrfs: continuing balance\n");
+ ret = btrfs_balance(bctl, NULL);
+ }
+
+ mutex_unlock(&fs_info->balance_mutex);
+ mutex_unlock(&fs_info->volume_mutex);
+ return ret;
+}
+
+int btrfs_recover_balance(struct btrfs_root *tree_root)
+{
+ struct task_struct *tsk;
+ struct btrfs_balance_control *bctl;
+ struct btrfs_balance_item *item;
+ struct btrfs_disk_balance_args disk_bargs;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key key;
+ int ret;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
+ if (!bctl) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ key.objectid = BTRFS_BALANCE_OBJECTID;
+ key.type = BTRFS_BALANCE_ITEM_KEY;
+ key.offset = 0;
+
+ ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
+ if (ret < 0)
+ goto out_bctl;
+ if (ret > 0) { /* ret = -ENOENT; */
+ ret = 0;
+ goto out_bctl;
+ }
+
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
+
+ bctl->fs_info = tree_root->fs_info;
+ bctl->flags = btrfs_balance_flags(leaf, item) | BTRFS_BALANCE_RESUME;
+
+ btrfs_balance_data(leaf, item, &disk_bargs);
+ btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
+ btrfs_balance_meta(leaf, item, &disk_bargs);
+ btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
+ btrfs_balance_sys(leaf, item, &disk_bargs);
+ btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
+
+ tsk = kthread_run(balance_kthread, bctl, "btrfs-balance");
+ if (IS_ERR(tsk))
+ ret = PTR_ERR(tsk);
+ else
+ goto out;
+
+out_bctl:
+ kfree(bctl);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
+{
+ int ret = 0;
+
+ mutex_lock(&fs_info->balance_mutex);
+ if (!fs_info->balance_ctl) {
+ mutex_unlock(&fs_info->balance_mutex);
+ return -ENOTCONN;
+ }
+
+ if (atomic_read(&fs_info->balance_running)) {
+ atomic_inc(&fs_info->balance_pause_req);
+ mutex_unlock(&fs_info->balance_mutex);
+
+ wait_event(fs_info->balance_wait_q,
+ atomic_read(&fs_info->balance_running) == 0);
+
+ mutex_lock(&fs_info->balance_mutex);
+ /* we are good with balance_ctl ripped off from under us */
+ BUG_ON(atomic_read(&fs_info->balance_running));
+ atomic_dec(&fs_info->balance_pause_req);
+ } else {
+ ret = -ENOTCONN;
+ }
+
+ mutex_unlock(&fs_info->balance_mutex);
+ return ret;
+}
+
+int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
+{
+ mutex_lock(&fs_info->balance_mutex);
+ if (!fs_info->balance_ctl) {
+ mutex_unlock(&fs_info->balance_mutex);
+ return -ENOTCONN;
+ }
+
+ atomic_inc(&fs_info->balance_cancel_req);
+ /*
+ * if we are running just wait and return, balance item is
+ * deleted in btrfs_balance in this case
+ */
+ if (atomic_read(&fs_info->balance_running)) {
+ mutex_unlock(&fs_info->balance_mutex);
+ wait_event(fs_info->balance_wait_q,
+ atomic_read(&fs_info->balance_running) == 0);
+ mutex_lock(&fs_info->balance_mutex);
+ } else {
+ /* __cancel_balance needs volume_mutex */
+ mutex_unlock(&fs_info->balance_mutex);
+ mutex_lock(&fs_info->volume_mutex);
+ mutex_lock(&fs_info->balance_mutex);
+
+ if (fs_info->balance_ctl)
+ __cancel_balance(fs_info);
+
+ mutex_unlock(&fs_info->volume_mutex);
+ }
+
+ BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
+ atomic_dec(&fs_info->balance_cancel_req);
+ mutex_unlock(&fs_info->balance_mutex);
+ return 0;
+}
+
+/*
+ * 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;
+
+ do {
+ 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++;
+ } while (key.offset-- > 0);
+
+ 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_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;
+
+ BUG_ON(!alloc_profile_is_valid(type, 0));
+
+ 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) {
+ /* for larger filesystems, use larger metadata chunks */
+ if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
+ max_stripe_size = 1024 * 1024 * 1024;
+ else
+ max_stripe_size = 256 * 1024 * 1024;
+ max_chunk_size = max_stripe_size;
+ } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ max_stripe_size = 32 * 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(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 * ndevs > max_chunk_size * ncopies) {
+ stripe_size = max_chunk_size * ncopies;
+ do_div(stripe_size, ndevs);
+ }
+
+ do_div(stripe_size, dev_stripes);
+
+ /* align to BTRFS_STRIPE_LEN */
+ 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);
+ free_extent_map(em);
+ if (ret)
+ goto error;
+
+ ret = btrfs_make_block_group(trans, extent_root, 0, type,
+ BTRFS_FIRST_CHUNK_TREE_OBJECTID,
+ start, num_bytes);
+ if (ret)
+ goto error;
+
+ 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);
+ if (ret) {
+ btrfs_abort_transaction(trans, extent_root, ret);
+ goto error;
+ }
+ }
+
+ 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);
+ if (ret)
+ goto out_free;
+ 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);
+
+ if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
+ /*
+ * TODO: Cleanup of inserted chunk root in case of
+ * failure.
+ */
+ ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
+ item_size);
+ }
+
+out_free:
+ kfree(chunk);
+ return ret;
+}
+
+/*
+ * 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);
+ if (ret)
+ return 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);
+ if (ret)
+ return 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);
+ if (ret)
+ goto abort;
+
+ ret = btrfs_add_device(trans, fs_info->chunk_root, device);
+ if (ret)
+ goto abort;
+
+ /*
+ * 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);
+ if (ret)
+ goto abort;
+
+ ret = __finish_chunk_alloc(trans, extent_root, sys_map,
+ sys_chunk_offset, sys_chunk_size,
+ sys_stripe_size);
+ if (ret)
+ goto abort;
+
+ return 0;
+
+abort:
+ btrfs_abort_transaction(trans, root, ret);
+ return ret;
+}
+
+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 stripe_index;
+ int i;
+ int ret = 0;
+ int num_stripes;
+ int max_errors = 0;
+ struct btrfs_bio *bbio = NULL;
+
+ 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;
+
+ 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 {
+ int old_stripe_index = stripe_index;
+ stripe_index = find_live_mirror(map, stripe_index,
+ map->sub_stripes, stripe_index +
+ current->pid % map->sub_stripes);
+ mirror_num = stripe_index - old_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);
+
+ bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS);
+ if (!bbio) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ atomic_set(&bbio->error, 0);
+
+ if (rw & REQ_DISCARD) {
+ int factor = 0;
+ int sub_stripes = 0;
+ u64 stripes_per_dev = 0;
+ u32 remaining_stripes = 0;
+ u32 last_stripe = 0;
+
+ if (map->type &
+ (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
+ if (map->type & BTRFS_BLOCK_GROUP_RAID0)
+ sub_stripes = 1;
+ else
+ sub_stripes = map->sub_stripes;
+
+ factor = map->num_stripes / sub_stripes;
+ stripes_per_dev = div_u64_rem(stripe_nr_end -
+ stripe_nr_orig,
+ factor,
+ &remaining_stripes);
+ div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
+ last_stripe *= sub_stripes;
+ }
+
+ 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 |
+ BTRFS_BLOCK_GROUP_RAID10)) {
+ bbio->stripes[i].length = stripes_per_dev *
+ map->stripe_len;
+
+ if (i / sub_stripes < remaining_stripes)
+ bbio->stripes[i].length +=
+ map->stripe_len;
+
+ /*
+ * Special for the first stripe and
+ * the last stripe:
+ *
+ * |-------|...|-------|
+ * |----------|
+ * off end_off
+ */
+ if (i < sub_stripes)
+ bbio->stripes[i].length -=
+ stripe_offset;
+
+ if (stripe_index >= last_stripe &&
+ stripe_index <= (last_stripe +
+ sub_stripes - 1))
+ bbio->stripes[i].length -=
+ stripe_end_offset;
+
+ if (i == sub_stripes - 1)
+ stripe_offset = 0;
+ } 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 (rw & REQ_WRITE) {
+ if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
+ BTRFS_BLOCK_GROUP_RAID10 |
+ BTRFS_BLOCK_GROUP_DUP)) {
+ max_errors = 1;
+ }
+ }
+
+ *bbio_ret = bbio;
+ bbio->num_stripes = num_stripes;
+ bbio->max_errors = max_errors;
+ bbio->mirror_num = mirror_num;
+out:
+ free_extent_map(em);
+ return ret;
+}
+
+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); /* -ENOMEM */
+
+ 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 void 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);
+ btrfsic_submit_bio(rw, bio);
+ bio_put(bio);
+ return;
+ }
+
+ /*
+ * 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);
+}
+
+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);
+ if (ret) /* -ENOMEM */
+ return 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); /* -ENOMEM */
+ } 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
+ btrfsic_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); /* Tree corruption */
+ free_extent_map(em);
+
+ return 0;
+}
+
+static void 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);
+}
+
+static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
+{
+ struct btrfs_fs_devices *fs_devices;
+ int ret;
+
+ BUG_ON(!mutex_is_locked(&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) {
+ free_fs_devices(fs_devices);
+ 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:
+ 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);
+ /*
+ * The sb extent buffer is artifical and just used to read the system array.
+ * btrfs_set_buffer_uptodate() call does not properly mark all it's
+ * pages up-to-date when the page is larger: extent does not cover the
+ * whole page and consequently check_page_uptodate does not find all
+ * the page's extents up-to-date (the hole beyond sb),
+ * write_extent_buffer then triggers a WARN_ON.
+ *
+ * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
+ * but sb spans only this function. Add an explicit SetPageUptodate call
+ * to silence the warning eg. on PowerPC 64.
+ */
+ if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
+ SetPageUptodate(sb->pages[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;
+
+ mutex_lock(&uuid_mutex);
+ lock_chunks(root);
+
+ /* 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:
+ unlock_chunks(root);
+ mutex_unlock(&uuid_mutex);
+
+ btrfs_free_path(path);
+ return ret;
+}