]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - fs/btrfs/volumes.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...
[karo-tx-linux.git] / fs / btrfs / volumes.c
index 2c2d6d1d8eee929fc910a82cd17fbec79803cbb2..d47289c715c814f47c7842349afc942640310238 100644 (file)
@@ -50,7 +50,7 @@ static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
 
-static DEFINE_MUTEX(uuid_mutex);
+DEFINE_MUTEX(uuid_mutex);
 static LIST_HEAD(fs_uuids);
 
 static void lock_chunks(struct btrfs_root *root)
@@ -74,6 +74,7 @@ static struct btrfs_fs_devices *__alloc_fs_devices(void)
        mutex_init(&fs_devs->device_list_mutex);
 
        INIT_LIST_HEAD(&fs_devs->devices);
+       INIT_LIST_HEAD(&fs_devs->resized_devices);
        INIT_LIST_HEAD(&fs_devs->alloc_list);
        INIT_LIST_HEAD(&fs_devs->list);
 
@@ -154,11 +155,13 @@ static struct btrfs_device *__alloc_device(void)
 
        INIT_LIST_HEAD(&dev->dev_list);
        INIT_LIST_HEAD(&dev->dev_alloc_list);
+       INIT_LIST_HEAD(&dev->resized_list);
 
        spin_lock_init(&dev->io_lock);
 
        spin_lock_init(&dev->reada_lock);
        atomic_set(&dev->reada_in_flight, 0);
+       atomic_set(&dev->dev_stats_ccnt, 0);
        INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_WAIT);
        INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_WAIT);
 
@@ -474,14 +477,13 @@ static noinline int device_list_add(const char *path,
                        return PTR_ERR(fs_devices);
 
                list_add(&fs_devices->list, &fs_uuids);
-               fs_devices->latest_devid = devid;
-               fs_devices->latest_trans = found_transid;
 
                device = NULL;
        } else {
                device = __find_device(&fs_devices->devices, devid,
                                       disk_super->dev_item.uuid);
        }
+
        if (!device) {
                if (fs_devices->opened)
                        return -EBUSY;
@@ -565,10 +567,6 @@ static noinline int device_list_add(const char *path,
        if (!fs_devices->opened)
                device->generation = found_transid;
 
-       if (found_transid > fs_devices->latest_trans) {
-               fs_devices->latest_devid = devid;
-               fs_devices->latest_trans = found_transid;
-       }
        *fs_devices_ret = fs_devices;
 
        return ret;
@@ -584,8 +582,7 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
        if (IS_ERR(fs_devices))
                return fs_devices;
 
-       fs_devices->latest_devid = orig->latest_devid;
-       fs_devices->latest_trans = orig->latest_trans;
+       mutex_lock(&orig->device_list_mutex);
        fs_devices->total_devices = orig->total_devices;
 
        /* We have held the volume lock, it is safe to get the devices. */
@@ -614,8 +611,10 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
                device->fs_devices = fs_devices;
                fs_devices->num_devices++;
        }
+       mutex_unlock(&orig->device_list_mutex);
        return fs_devices;
 error:
+       mutex_unlock(&orig->device_list_mutex);
        free_fs_devices(fs_devices);
        return ERR_PTR(-ENOMEM);
 }
@@ -624,10 +623,7 @@ void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
                               struct btrfs_fs_devices *fs_devices, int step)
 {
        struct btrfs_device *device, *next;
-
-       struct block_device *latest_bdev = NULL;
-       u64 latest_devid = 0;
-       u64 latest_transid = 0;
+       struct btrfs_device *latest_dev = NULL;
 
        mutex_lock(&uuid_mutex);
 again:
@@ -635,11 +631,9 @@ again:
        list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
                if (device->in_fs_metadata) {
                        if (!device->is_tgtdev_for_dev_replace &&
-                           (!latest_transid ||
-                            device->generation > latest_transid)) {
-                               latest_devid = device->devid;
-                               latest_transid = device->generation;
-                               latest_bdev = device->bdev;
+                           (!latest_dev ||
+                            device->generation > latest_dev->generation)) {
+                               latest_dev = device;
                        }
                        continue;
                }
@@ -681,9 +675,7 @@ again:
                goto again;
        }
 
-       fs_devices->latest_bdev = latest_bdev;
-       fs_devices->latest_devid = latest_devid;
-       fs_devices->latest_trans = latest_transid;
+       fs_devices->latest_bdev = latest_dev->bdev;
 
        mutex_unlock(&uuid_mutex);
 }
@@ -732,8 +724,6 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
                        fs_devices->rw_devices--;
                }
 
-               if (device->can_discard)
-                       fs_devices->num_can_discard--;
                if (device->missing)
                        fs_devices->missing_devices--;
 
@@ -798,11 +788,9 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
        struct block_device *bdev;
        struct list_head *head = &fs_devices->devices;
        struct btrfs_device *device;
-       struct block_device *latest_bdev = NULL;
+       struct btrfs_device *latest_dev = 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;
@@ -830,11 +818,9 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
                        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 (!latest_dev ||
+                   device->generation > latest_dev->generation)
+                       latest_dev = device;
 
                if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
                        device->writeable = 0;
@@ -844,10 +830,8 @@ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
                }
 
                q = bdev_get_queue(bdev);
-               if (blk_queue_discard(q)) {
+               if (blk_queue_discard(q))
                        device->can_discard = 1;
-                       fs_devices->num_can_discard++;
-               }
 
                device->bdev = bdev;
                device->in_fs_metadata = 0;
@@ -877,9 +861,7 @@ error_brelse:
        }
        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->latest_bdev = latest_dev->bdev;
        fs_devices->total_rw_bytes = 0;
 out:
        return ret;
@@ -1053,7 +1035,7 @@ int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
                if (key.objectid > device->devid)
                        break;
 
-               if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
+               if (key.type != BTRFS_DEV_EXTENT_KEY)
                        goto next;
 
                dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
@@ -1205,7 +1187,7 @@ again:
                if (key.objectid > device->devid)
                        break;
 
-               if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
+               if (key.type != BTRFS_DEV_EXTENT_KEY)
                        goto next;
 
                if (key.offset > search_start) {
@@ -1284,7 +1266,7 @@ out:
 
 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
                          struct btrfs_device *device,
-                         u64 start)
+                         u64 start, u64 *dev_extent_len)
 {
        int ret;
        struct btrfs_path *path;
@@ -1326,13 +1308,8 @@ again:
                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);
-       }
+       *dev_extent_len = btrfs_dev_extent_length(leaf, extent);
+
        ret = btrfs_del_item(trans, root, path);
        if (ret) {
                btrfs_error(root->fs_info, ret,
@@ -1482,8 +1459,10 @@ static int btrfs_add_device(struct btrfs_trans_handle *trans,
        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_set_device_total_bytes(leaf, dev_item,
+                                    btrfs_device_get_disk_total_bytes(device));
+       btrfs_set_device_bytes_used(leaf, dev_item,
+                                   btrfs_device_get_bytes_used(device));
        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);
@@ -1539,7 +1518,6 @@ static int btrfs_rm_dev_item(struct btrfs_root *root,
        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)
@@ -1555,7 +1533,6 @@ static int btrfs_rm_dev_item(struct btrfs_root *root,
                goto out;
 out:
        btrfs_free_path(path);
-       unlock_chunks(root);
        btrfs_commit_transaction(trans, root);
        return ret;
 }
@@ -1671,8 +1648,8 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
        if (device->writeable) {
                lock_chunks(root);
                list_del_init(&device->dev_alloc_list);
+               device->fs_devices->rw_devices--;
                unlock_chunks(root);
-               root->fs_info->fs_devices->rw_devices--;
                clear_super = true;
        }
 
@@ -1691,11 +1668,6 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
        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->fs_info, device);
 
@@ -1749,9 +1721,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
                        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);
        }
 
@@ -1824,8 +1794,8 @@ error_undo:
                lock_chunks(root);
                list_add(&device->dev_alloc_list,
                         &root->fs_info->fs_devices->alloc_list);
+               device->fs_devices->rw_devices++;
                unlock_chunks(root);
-               root->fs_info->fs_devices->rw_devices++;
        }
        goto error_brelse;
 }
@@ -1833,29 +1803,57 @@ error_undo:
 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
                                 struct btrfs_device *srcdev)
 {
+       struct btrfs_fs_devices *fs_devices;
+
        WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
 
+       /*
+        * in case of fs with no seed, srcdev->fs_devices will point
+        * to fs_devices of fs_info. However when the dev being replaced is
+        * a seed dev it will point to the seed's local fs_devices. In short
+        * srcdev will have its correct fs_devices in both the cases.
+        */
+       fs_devices = srcdev->fs_devices;
+
        list_del_rcu(&srcdev->dev_list);
        list_del_rcu(&srcdev->dev_alloc_list);
-       fs_info->fs_devices->num_devices--;
-       if (srcdev->missing) {
-               fs_info->fs_devices->missing_devices--;
-               fs_info->fs_devices->rw_devices++;
-       }
-       if (srcdev->can_discard)
-               fs_info->fs_devices->num_can_discard--;
-       if (srcdev->bdev) {
-               fs_info->fs_devices->open_devices--;
+       fs_devices->num_devices--;
+       if (srcdev->missing)
+               fs_devices->missing_devices--;
 
-               /*
-                * zero out the old super if it is not writable
-                * (e.g. seed device)
-                */
-               if (srcdev->writeable)
-                       btrfs_scratch_superblock(srcdev);
+       if (srcdev->writeable) {
+               fs_devices->rw_devices--;
+               /* zero out the old super if it is writable */
+               btrfs_scratch_superblock(srcdev);
        }
 
+       if (srcdev->bdev)
+               fs_devices->open_devices--;
+
        call_rcu(&srcdev->rcu, free_device);
+
+       /*
+        * unless fs_devices is seed fs, num_devices shouldn't go
+        * zero
+        */
+       BUG_ON(!fs_devices->num_devices && !fs_devices->seeding);
+
+       /* if this is no devs we rather delete the fs_devices */
+       if (!fs_devices->num_devices) {
+               struct btrfs_fs_devices *tmp_fs_devices;
+
+               tmp_fs_devices = fs_info->fs_devices;
+               while (tmp_fs_devices) {
+                       if (tmp_fs_devices->seed == fs_devices) {
+                               tmp_fs_devices->seed = fs_devices->seed;
+                               break;
+                       }
+                       tmp_fs_devices = tmp_fs_devices->seed;
+               }
+               fs_devices->seed = NULL;
+               __btrfs_close_devices(fs_devices);
+               free_fs_devices(fs_devices);
+       }
 }
 
 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
@@ -1863,6 +1861,7 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 {
        struct btrfs_device *next_device;
 
+       mutex_lock(&uuid_mutex);
        WARN_ON(!tgtdev);
        mutex_lock(&fs_info->fs_devices->device_list_mutex);
        if (tgtdev->bdev) {
@@ -1870,8 +1869,6 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
                fs_info->fs_devices->open_devices--;
        }
        fs_info->fs_devices->num_devices--;
-       if (tgtdev->can_discard)
-               fs_info->fs_devices->num_can_discard++;
 
        next_device = list_entry(fs_info->fs_devices->devices.next,
                                 struct btrfs_device, dev_list);
@@ -1884,6 +1881,7 @@ void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
        call_rcu(&tgtdev->rcu, free_device);
 
        mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+       mutex_unlock(&uuid_mutex);
 }
 
 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
@@ -1982,17 +1980,17 @@ static int btrfs_prepare_sprout(struct btrfs_root *root)
        mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
        list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
                              synchronize_rcu);
+       list_for_each_entry(device, &seed_devices->devices, dev_list)
+               device->fs_devices = seed_devices;
 
+       lock_chunks(root);
        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;
-       }
+       unlock_chunks(root);
 
        fs_devices->seeding = 0;
        fs_devices->num_devices = 0;
        fs_devices->open_devices = 0;
        fs_devices->missing_devices = 0;
-       fs_devices->num_can_discard = 0;
        fs_devices->rotating = 0;
        fs_devices->seed = seed_devices;
 
@@ -2092,7 +2090,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
        struct list_head *devices;
        struct super_block *sb = root->fs_info->sb;
        struct rcu_string *name;
-       u64 total_bytes;
+       u64 tmp;
        int seeding_dev = 0;
        int ret = 0;
 
@@ -2148,8 +2146,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
                goto error;
        }
 
-       lock_chunks(root);
-
        q = bdev_get_queue(bdev);
        if (blk_queue_discard(q))
                device->can_discard = 1;
@@ -2160,6 +2156,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
        device->sector_size = root->sectorsize;
        device->total_bytes = i_size_read(bdev->bd_inode);
        device->disk_total_bytes = device->total_bytes;
+       device->commit_total_bytes = device->total_bytes;
        device->dev_root = root->fs_info->dev_root;
        device->bdev = bdev;
        device->in_fs_metadata = 1;
@@ -2177,6 +2174,7 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
        device->fs_devices = root->fs_info->fs_devices;
 
        mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
+       lock_chunks(root);
        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);
@@ -2184,8 +2182,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
        root->fs_info->fs_devices->open_devices++;
        root->fs_info->fs_devices->rw_devices++;
        root->fs_info->fs_devices->total_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);
@@ -2195,26 +2191,45 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
        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);
+       tmp = btrfs_super_total_bytes(root->fs_info->super_copy);
        btrfs_set_super_total_bytes(root->fs_info->super_copy,
-                                   total_bytes + device->total_bytes);
+                                   tmp + device->total_bytes);
 
-       total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
+       tmp = btrfs_super_num_devices(root->fs_info->super_copy);
        btrfs_set_super_num_devices(root->fs_info->super_copy,
-                                   total_bytes + 1);
+                                   tmp + 1);
 
        /* add sysfs device entry */
        btrfs_kobj_add_device(root->fs_info, device);
 
+       /*
+        * we've got more storage, clear any full flags on the space
+        * infos
+        */
+       btrfs_clear_space_info_full(root->fs_info);
+
+       unlock_chunks(root);
        mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 
        if (seeding_dev) {
-               char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
+               lock_chunks(root);
                ret = init_first_rw_device(trans, root, device);
+               unlock_chunks(root);
                if (ret) {
                        btrfs_abort_transaction(trans, root, ret);
                        goto error_trans;
                }
+       }
+
+       ret = btrfs_add_device(trans, root, device);
+       if (ret) {
+               btrfs_abort_transaction(trans, root, ret);
+               goto error_trans;
+       }
+
+       if (seeding_dev) {
+               char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
+
                ret = btrfs_finish_sprout(trans, root);
                if (ret) {
                        btrfs_abort_transaction(trans, root, ret);
@@ -2228,21 +2243,8 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
                                                root->fs_info->fsid);
                if (kobject_rename(&root->fs_info->super_kobj, fsid_buf))
                        goto error_trans;
-       } else {
-               ret = btrfs_add_device(trans, root, device);
-               if (ret) {
-                       btrfs_abort_transaction(trans, root, 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);
        root->fs_info->num_tolerated_disk_barrier_failures =
                btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
        ret = btrfs_commit_transaction(trans, root);
@@ -2274,7 +2276,6 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
        return ret;
 
 error_trans:
-       unlock_chunks(root);
        btrfs_end_transaction(trans, root);
        rcu_string_free(device->name);
        btrfs_kobj_rm_device(root->fs_info, device);
@@ -2289,6 +2290,7 @@ error:
 }
 
 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
+                                 struct btrfs_device *srcdev,
                                  struct btrfs_device **device_out)
 {
        struct request_queue *q;
@@ -2301,24 +2303,38 @@ int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
        int ret = 0;
 
        *device_out = NULL;
-       if (fs_info->fs_devices->seeding)
+       if (fs_info->fs_devices->seeding) {
+               btrfs_err(fs_info, "the filesystem is a seed filesystem!");
                return -EINVAL;
+       }
 
        bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
                                  fs_info->bdev_holder);
-       if (IS_ERR(bdev))
+       if (IS_ERR(bdev)) {
+               btrfs_err(fs_info, "target device %s is invalid!", device_path);
                return PTR_ERR(bdev);
+       }
 
        filemap_write_and_wait(bdev->bd_inode->i_mapping);
 
        devices = &fs_info->fs_devices->devices;
        list_for_each_entry(device, devices, dev_list) {
                if (device->bdev == bdev) {
+                       btrfs_err(fs_info, "target device is in the filesystem!");
                        ret = -EEXIST;
                        goto error;
                }
        }
 
+
+       if (i_size_read(bdev->bd_inode) <
+           btrfs_device_get_total_bytes(srcdev)) {
+               btrfs_err(fs_info, "target device is smaller than source device!");
+               ret = -EINVAL;
+               goto error;
+       }
+
+
        device = btrfs_alloc_device(NULL, &devid, NULL);
        if (IS_ERR(device)) {
                ret = PTR_ERR(device);
@@ -2342,8 +2358,12 @@ int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
        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->total_bytes = btrfs_device_get_total_bytes(srcdev);
+       device->disk_total_bytes = btrfs_device_get_disk_total_bytes(srcdev);
+       device->bytes_used = btrfs_device_get_bytes_used(srcdev);
+       ASSERT(list_empty(&srcdev->resized_list));
+       device->commit_total_bytes = srcdev->commit_total_bytes;
+       device->commit_bytes_used = device->bytes_used;
        device->dev_root = fs_info->dev_root;
        device->bdev = bdev;
        device->in_fs_metadata = 1;
@@ -2355,8 +2375,6 @@ int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
        list_add(&device->dev_list, &fs_info->fs_devices->devices);
        fs_info->fs_devices->num_devices++;
        fs_info->fs_devices->open_devices++;
-       if (device->can_discard)
-               fs_info->fs_devices->num_can_discard++;
        mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 
        *device_out = device;
@@ -2415,8 +2433,10 @@ static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
        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_set_device_total_bytes(leaf, dev_item,
+                                    btrfs_device_get_disk_total_bytes(device));
+       btrfs_set_device_bytes_used(leaf, dev_item,
+                                   btrfs_device_get_bytes_used(device));
        btrfs_mark_buffer_dirty(leaf);
 
 out:
@@ -2424,40 +2444,44 @@ out:
        return ret;
 }
 
-static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
+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;
+       struct btrfs_fs_devices *fs_devices;
+       u64 old_total;
+       u64 diff;
 
        if (!device->writeable)
                return -EACCES;
+
+       lock_chunks(device->dev_root);
+       old_total = btrfs_super_total_bytes(super_copy);
+       diff = new_size - device->total_bytes;
+
        if (new_size <= device->total_bytes ||
-           device->is_tgtdev_for_dev_replace)
+           device->is_tgtdev_for_dev_replace) {
+               unlock_chunks(device->dev_root);
                return -EINVAL;
+       }
+
+       fs_devices = device->dev_root->fs_info->fs_devices;
 
        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_device_set_total_bytes(device, new_size);
+       btrfs_device_set_disk_total_bytes(device, new_size);
        btrfs_clear_space_info_full(device->dev_root->fs_info);
+       if (list_empty(&device->resized_list))
+               list_add_tail(&device->resized_list,
+                             &fs_devices->resized_devices);
+       unlock_chunks(device->dev_root);
 
        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,
@@ -2509,6 +2533,7 @@ static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
        u32 cur;
        struct btrfs_key key;
 
+       lock_chunks(root);
        array_size = btrfs_super_sys_array_size(super_copy);
 
        ptr = super_copy->sys_chunk_array;
@@ -2538,79 +2563,95 @@ static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
                        cur += len;
                }
        }
+       unlock_chunks(root);
        return ret;
 }
 
-static int btrfs_relocate_chunk(struct btrfs_root *root,
-                        u64 chunk_tree, u64 chunk_objectid,
-                        u64 chunk_offset)
+int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
+                      struct btrfs_root *root, u64 chunk_offset)
 {
        struct extent_map_tree *em_tree;
-       struct btrfs_root *extent_root;
-       struct btrfs_trans_handle *trans;
        struct extent_map *em;
+       struct btrfs_root *extent_root = root->fs_info->extent_root;
        struct map_lookup *map;
-       int ret;
-       int i;
+       u64 dev_extent_len = 0;
+       u64 chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+       u64 chunk_tree = root->fs_info->chunk_root->objectid;
+       int i, ret = 0;
 
+       /* Just in case */
        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);
-       if (IS_ERR(trans)) {
-               ret = PTR_ERR(trans);
-               btrfs_std_error(root->fs_info, ret);
-               return ret;
-       }
-
-       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);
+       if (!em || em->start > chunk_offset ||
+           em->start + em->len < chunk_offset) {
+               /*
+                * This is a logic error, but we don't want to just rely on the
+                * user having built with ASSERT enabled, so if ASSERT doens't
+                * do anything we still error out.
+                */
+               ASSERT(0);
+               if (em)
+                       free_extent_map(em);
+               return -EINVAL;
+       }
        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);
+               struct btrfs_device *device = map->stripes[i].dev;
+               ret = btrfs_free_dev_extent(trans, device,
+                                           map->stripes[i].physical,
+                                           &dev_extent_len);
+               if (ret) {
+                       btrfs_abort_transaction(trans, root, ret);
+                       goto out;
+               }
+
+               if (device->bytes_used > 0) {
+                       lock_chunks(root);
+                       btrfs_device_set_bytes_used(device,
+                                       device->bytes_used - dev_extent_len);
+                       spin_lock(&root->fs_info->free_chunk_lock);
+                       root->fs_info->free_chunk_space += dev_extent_len;
+                       spin_unlock(&root->fs_info->free_chunk_lock);
+                       btrfs_clear_space_info_full(root->fs_info);
+                       unlock_chunks(root);
+               }
 
                if (map->stripes[i].dev) {
                        ret = btrfs_update_device(trans, map->stripes[i].dev);
-                       BUG_ON(ret);
+                       if (ret) {
+                               btrfs_abort_transaction(trans, root, ret);
+                               goto out;
+                       }
                }
        }
        ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
                               chunk_offset);
-
-       BUG_ON(ret);
+       if (ret) {
+               btrfs_abort_transaction(trans, root, ret);
+               goto out;
+       }
 
        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);
+               if (ret) {
+                       btrfs_abort_transaction(trans, root, ret);
+                       goto out;
+               }
        }
 
        ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
-       BUG_ON(ret);
+       if (ret) {
+               btrfs_abort_transaction(trans, extent_root, ret);
+               goto out;
+       }
 
        write_lock(&em_tree->lock);
        remove_extent_mapping(em_tree, em);
@@ -2618,12 +2659,46 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 
        /* once for the tree */
        free_extent_map(em);
+out:
        /* once for us */
        free_extent_map(em);
+       return ret;
+}
 
-       unlock_chunks(root);
+static int btrfs_relocate_chunk(struct btrfs_root *root,
+                        u64 chunk_tree, u64 chunk_objectid,
+                        u64 chunk_offset)
+{
+       struct btrfs_root *extent_root;
+       struct btrfs_trans_handle *trans;
+       int ret;
+
+       root = root->fs_info->chunk_root;
+       extent_root = root->fs_info->extent_root;
+
+       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);
+       if (IS_ERR(trans)) {
+               ret = PTR_ERR(trans);
+               btrfs_std_error(root->fs_info, ret);
+               return ret;
+       }
+
+       /*
+        * step two, delete the device extents and the
+        * chunk tree entries
+        */
+       ret = btrfs_remove_chunk(trans, root, chunk_offset);
        btrfs_end_transaction(trans, root);
-       return 0;
+       return ret;
 }
 
 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
@@ -2676,8 +2751,8 @@ again:
                                                   found_key.offset);
                        if (ret == -ENOSPC)
                                failed++;
-                       else if (ret)
-                               BUG();
+                       else
+                               BUG_ON(ret);
                }
 
                if (found_key.offset == 0)
@@ -3084,11 +3159,12 @@ static int __btrfs_balance(struct btrfs_fs_info *fs_info)
        /* 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;
+               old_size = btrfs_device_get_total_bytes(device);
                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 ||
+                   btrfs_device_get_total_bytes(device) -
+                   btrfs_device_get_bytes_used(device) > size_to_free ||
                    device->is_tgtdev_for_dev_replace)
                        continue;
 
@@ -3643,8 +3719,6 @@ static int btrfs_uuid_scan_kthread(void *data)
        max_key.type = BTRFS_ROOT_ITEM_KEY;
        max_key.offset = (u64)-1;
 
-       path->keep_locks = 1;
-
        while (1) {
                ret = btrfs_search_forward(root, &key, path, 0);
                if (ret) {
@@ -3896,8 +3970,8 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
        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;
+       u64 old_size = btrfs_device_get_total_bytes(device);
+       u64 diff = old_size - new_size;
 
        if (device->is_tgtdev_for_dev_replace)
                return -EINVAL;
@@ -3910,7 +3984,7 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
 
        lock_chunks(root);
 
-       device->total_bytes = new_size;
+       btrfs_device_set_total_bytes(device, new_size);
        if (device->writeable) {
                device->fs_devices->total_rw_bytes -= diff;
                spin_lock(&root->fs_info->free_chunk_lock);
@@ -3976,7 +4050,7 @@ again:
                ret = -ENOSPC;
                lock_chunks(root);
 
-               device->total_bytes = old_size;
+               btrfs_device_set_total_bytes(device, old_size);
                if (device->writeable)
                        device->fs_devices->total_rw_bytes += diff;
                spin_lock(&root->fs_info->free_chunk_lock);
@@ -3994,18 +4068,17 @@ again:
        }
 
        lock_chunks(root);
+       btrfs_device_set_disk_total_bytes(device, new_size);
+       if (list_empty(&device->resized_list))
+               list_add_tail(&device->resized_list,
+                             &root->fs_info->fs_devices->resized_devices);
 
-       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);
+
+       /* Now btrfs_update_device() will change the on-disk size. */
+       ret = btrfs_update_device(trans, device);
        btrfs_end_transaction(trans, root);
 done:
        btrfs_free_path(path);
@@ -4021,10 +4094,13 @@ static int btrfs_add_system_chunk(struct btrfs_root *root,
        u32 array_size;
        u8 *ptr;
 
+       lock_chunks(root);
        array_size = btrfs_super_sys_array_size(super_copy);
        if (array_size + item_size + sizeof(disk_key)
-                       > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
+                       > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) {
+               unlock_chunks(root);
                return -EFBIG;
+       }
 
        ptr = super_copy->sys_chunk_array + array_size;
        btrfs_cpu_key_to_disk(&disk_key, key);
@@ -4033,6 +4109,8 @@ static int btrfs_add_system_chunk(struct btrfs_root *root,
        memcpy(ptr, chunk, item_size);
        item_size += sizeof(disk_key);
        btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
+       unlock_chunks(root);
+
        return 0;
 }
 
@@ -4402,6 +4480,16 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
        if (ret)
                goto error_del_extent;
 
+       for (i = 0; i < map->num_stripes; i++) {
+               num_bytes = map->stripes[i].dev->bytes_used + stripe_size;
+               btrfs_device_set_bytes_used(map->stripes[i].dev, num_bytes);
+       }
+
+       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);
+
        free_extent_map(em);
        check_raid56_incompat_flag(extent_root->fs_info, type);
 
@@ -4473,7 +4561,6 @@ int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
                device = map->stripes[i].dev;
                dev_offset = map->stripes[i].physical;
 
-               device->bytes_used += stripe_size;
                ret = btrfs_update_device(trans, device);
                if (ret)
                        goto out;
@@ -4486,11 +4573,6 @@ int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
                        goto out;
        }
 
-       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);
-
        stripe = &chunk->stripe;
        for (i = 0; i < map->num_stripes; i++) {
                device = map->stripes[i].dev;
@@ -4570,16 +4652,25 @@ static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
        alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
        ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
                                  alloc_profile);
-       if (ret) {
-               btrfs_abort_transaction(trans, root, ret);
-               goto out;
+       return ret;
+}
+
+static inline int btrfs_chunk_max_errors(struct map_lookup *map)
+{
+       int max_errors;
+
+       if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
+                        BTRFS_BLOCK_GROUP_RAID10 |
+                        BTRFS_BLOCK_GROUP_RAID5 |
+                        BTRFS_BLOCK_GROUP_DUP)) {
+               max_errors = 1;
+       } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
+               max_errors = 2;
+       } else {
+               max_errors = 0;
        }
 
-       ret = btrfs_add_device(trans, fs_info->chunk_root, device);
-       if (ret)
-               btrfs_abort_transaction(trans, root, ret);
-out:
-       return ret;
+       return max_errors;
 }
 
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
@@ -4588,6 +4679,7 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
        struct map_lookup *map;
        struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
        int readonly = 0;
+       int miss_ndevs = 0;
        int i;
 
        read_lock(&map_tree->map_tree.lock);
@@ -4596,18 +4688,27 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
        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->missing) {
+                       miss_ndevs++;
+                       continue;
+               }
+
                if (!map->stripes[i].dev->writeable) {
                        readonly = 1;
-                       break;
+                       goto end;
                }
        }
+
+       /*
+        * If the number of missing devices is larger than max errors,
+        * we can not write the data into that chunk successfully, so
+        * set it readonly.
+        */
+       if (miss_ndevs > btrfs_chunk_max_errors(map))
+               readonly = 1;
+end:
        free_extent_map(em);
        return readonly;
 }
@@ -5008,6 +5109,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
                        num_stripes = min_t(u64, map->num_stripes,
                                            stripe_nr_end - stripe_nr_orig);
                stripe_index = do_div(stripe_nr, map->num_stripes);
+               if (!(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)))
+                       mirror_num = 1;
        } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
                if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
                        num_stripes = map->num_stripes;
@@ -5111,6 +5214,9 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
                        /* We distribute the parity blocks across stripes */
                        tmp = stripe_nr + stripe_index;
                        stripe_index = do_div(tmp, map->num_stripes);
+                       if (!(rw & (REQ_WRITE | REQ_DISCARD |
+                                   REQ_GET_READ_MIRRORS)) && mirror_num <= 1)
+                               mirror_num = 1;
                }
        } else {
                /*
@@ -5218,16 +5324,8 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
                }
        }
 
-       if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
-               if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
-                                BTRFS_BLOCK_GROUP_RAID10 |
-                                BTRFS_BLOCK_GROUP_RAID5 |
-                                BTRFS_BLOCK_GROUP_DUP)) {
-                       max_errors = 1;
-               } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
-                       max_errors = 2;
-               }
-       }
+       if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
+               max_errors = btrfs_chunk_max_errors(map);
 
        if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
            dev_replace->tgtdev != NULL) {
@@ -5610,8 +5708,8 @@ static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
                name = rcu_dereference(dev->name);
                pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
                         "(%s id %llu), size=%u\n", rw,
-                        (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
-                        name->str, dev->devid, bio->bi_size);
+                        (u64)bio->bi_iter.bi_sector, (u_long)dev->bdev->bd_dev,
+                        name->str, dev->devid, bio->bi_iter.bi_size);
                rcu_read_unlock();
        }
 #endif
@@ -5789,10 +5887,10 @@ struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
 }
 
 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
+                                           struct btrfs_fs_devices *fs_devices,
                                            u64 devid, u8 *dev_uuid)
 {
        struct btrfs_device *device;
-       struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
 
        device = btrfs_alloc_device(NULL, &devid, dev_uuid);
        if (IS_ERR(device))
@@ -5929,7 +6027,8 @@ static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
                }
                if (!map->stripes[i].dev) {
                        map->stripes[i].dev =
-                               add_missing_dev(root, devid, uuid);
+                               add_missing_dev(root, root->fs_info->fs_devices,
+                                               devid, uuid);
                        if (!map->stripes[i].dev) {
                                free_extent_map(em);
                                return -EIO;
@@ -5956,7 +6055,9 @@ static void fill_device_from_item(struct extent_buffer *leaf,
        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->commit_total_bytes = device->disk_total_bytes;
        device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
+       device->commit_bytes_used = device->bytes_used;
        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);
@@ -5968,7 +6069,8 @@ static void fill_device_from_item(struct extent_buffer *leaf,
        read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
 }
 
-static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
+static struct btrfs_fs_devices *open_seed_devices(struct btrfs_root *root,
+                                                 u8 *fsid)
 {
        struct btrfs_fs_devices *fs_devices;
        int ret;
@@ -5977,49 +6079,56 @@ static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
 
        fs_devices = root->fs_info->fs_devices->seed;
        while (fs_devices) {
-               if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
-                       ret = 0;
-                       goto out;
-               }
+               if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE))
+                       return fs_devices;
+
                fs_devices = fs_devices->seed;
        }
 
        fs_devices = find_fsid(fsid);
        if (!fs_devices) {
-               ret = -ENOENT;
-               goto out;
+               if (!btrfs_test_opt(root, DEGRADED))
+                       return ERR_PTR(-ENOENT);
+
+               fs_devices = alloc_fs_devices(fsid);
+               if (IS_ERR(fs_devices))
+                       return fs_devices;
+
+               fs_devices->seeding = 1;
+               fs_devices->opened = 1;
+               return fs_devices;
        }
 
        fs_devices = clone_fs_devices(fs_devices);
-       if (IS_ERR(fs_devices)) {
-               ret = PTR_ERR(fs_devices);
-               goto out;
-       }
+       if (IS_ERR(fs_devices))
+               return fs_devices;
 
        ret = __btrfs_open_devices(fs_devices, FMODE_READ,
                                   root->fs_info->bdev_holder);
        if (ret) {
                free_fs_devices(fs_devices);
+               fs_devices = ERR_PTR(ret);
                goto out;
        }
 
        if (!fs_devices->seeding) {
                __btrfs_close_devices(fs_devices);
                free_fs_devices(fs_devices);
-               ret = -EINVAL;
+               fs_devices = ERR_PTR(-EINVAL);
                goto out;
        }
 
        fs_devices->seed = root->fs_info->fs_devices->seed;
        root->fs_info->fs_devices->seed = fs_devices;
 out:
-       return ret;
+       return fs_devices;
 }
 
 static int read_one_dev(struct btrfs_root *root,
                        struct extent_buffer *leaf,
                        struct btrfs_dev_item *dev_item)
 {
+       struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
        struct btrfs_device *device;
        u64 devid;
        int ret;
@@ -6033,31 +6142,48 @@ static int read_one_dev(struct btrfs_root *root,
                           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;
+               fs_devices = open_seed_devices(root, fs_uuid);
+               if (IS_ERR(fs_devices))
+                       return PTR_ERR(fs_devices);
        }
 
        device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
-       if (!device || !device->bdev) {
+       if (!device) {
                if (!btrfs_test_opt(root, DEGRADED))
                        return -EIO;
 
-               if (!device) {
-                       btrfs_warn(root->fs_info, "devid %llu missing", devid);
-                       device = add_missing_dev(root, devid, dev_uuid);
-                       if (!device)
-                               return -ENOMEM;
-               } else if (!device->missing) {
+               btrfs_warn(root->fs_info, "devid %llu missing", devid);
+               device = add_missing_dev(root, fs_devices, devid, dev_uuid);
+               if (!device)
+                       return -ENOMEM;
+       } else {
+               if (!device->bdev && !btrfs_test_opt(root, DEGRADED))
+                       return -EIO;
+
+               if(!device->bdev && !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->fs_devices->missing_devices++;
                        device->missing = 1;
                }
+
+               /* Move the device to its own fs_devices */
+               if (device->fs_devices != fs_devices) {
+                       ASSERT(device->missing);
+
+                       list_move(&device->dev_list, &fs_devices->devices);
+                       device->fs_devices->num_devices--;
+                       fs_devices->num_devices++;
+
+                       device->fs_devices->missing_devices--;
+                       fs_devices->missing_devices++;
+
+                       device->fs_devices = fs_devices;
+               }
        }
 
        if (device->fs_devices != root->fs_info->fs_devices) {
@@ -6373,16 +6499,18 @@ int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
        struct btrfs_root *dev_root = fs_info->dev_root;
        struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
        struct btrfs_device *device;
+       int stats_cnt;
        int ret = 0;
 
        mutex_lock(&fs_devices->device_list_mutex);
        list_for_each_entry(device, &fs_devices->devices, dev_list) {
-               if (!device->dev_stats_valid || !device->dev_stats_dirty)
+               if (!device->dev_stats_valid || !btrfs_dev_stats_dirty(device))
                        continue;
 
+               stats_cnt = atomic_read(&device->dev_stats_ccnt);
                ret = update_dev_stat_item(trans, dev_root, device);
                if (!ret)
-                       device->dev_stats_dirty = 0;
+                       atomic_sub(stats_cnt, &device->dev_stats_ccnt);
        }
        mutex_unlock(&fs_devices->device_list_mutex);
 
@@ -6481,3 +6609,51 @@ int btrfs_scratch_superblock(struct btrfs_device *device)
 
        return 0;
 }
+
+/*
+ * Update the size of all devices, which is used for writing out the
+ * super blocks.
+ */
+void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info)
+{
+       struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
+       struct btrfs_device *curr, *next;
+
+       if (list_empty(&fs_devices->resized_devices))
+               return;
+
+       mutex_lock(&fs_devices->device_list_mutex);
+       lock_chunks(fs_info->dev_root);
+       list_for_each_entry_safe(curr, next, &fs_devices->resized_devices,
+                                resized_list) {
+               list_del_init(&curr->resized_list);
+               curr->commit_total_bytes = curr->disk_total_bytes;
+       }
+       unlock_chunks(fs_info->dev_root);
+       mutex_unlock(&fs_devices->device_list_mutex);
+}
+
+/* Must be invoked during the transaction commit */
+void btrfs_update_commit_device_bytes_used(struct btrfs_root *root,
+                                       struct btrfs_transaction *transaction)
+{
+       struct extent_map *em;
+       struct map_lookup *map;
+       struct btrfs_device *dev;
+       int i;
+
+       if (list_empty(&transaction->pending_chunks))
+               return;
+
+       /* In order to kick the device replace finish process */
+       lock_chunks(root);
+       list_for_each_entry(em, &transaction->pending_chunks, list) {
+               map = (struct map_lookup *)em->bdev;
+
+               for (i = 0; i < map->num_stripes; i++) {
+                       dev = map->stripes[i].dev;
+                       dev->commit_bytes_used = dev->bytes_used;
+               }
+       }
+       unlock_chunks(root);
+}