INIT_LIST_HEAD(&device->dev_alloc_list);
mutex_lock(&fs_devices->device_list_mutex);
- list_add(&device->dev_list, &fs_devices->devices);
+ list_add_rcu(&device->dev_list, &fs_devices->devices);
mutex_unlock(&fs_devices->device_list_mutex);
device->fs_devices = fs_devices;
fs_devices->latest_trans = orig->latest_trans;
memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
- mutex_lock(&orig->device_list_mutex);
+ /* 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)
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);
}
mutex_lock(&uuid_mutex);
again:
- mutex_lock(&fs_devices->device_list_mutex);
+ /* This is the initialized path, it is safe to release the devices. */
list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
if (device->in_fs_metadata)
continue;
kfree(device->name);
kfree(device);
}
- mutex_unlock(&fs_devices->device_list_mutex);
if (fs_devices->seed) {
fs_devices = fs_devices->seed;
return 0;
}
+static void __free_device(struct work_struct *work)
+{
+ struct btrfs_device *device;
+
+ device = container_of(work, struct btrfs_device, rcu_work);
+
+ if (device->bdev)
+ blkdev_put(device->bdev, device->mode);
+
+ kfree(device->name);
+ kfree(device);
+}
+
+static void free_device(struct rcu_head *head)
+{
+ struct btrfs_device *device;
+
+ device = container_of(head, struct btrfs_device, rcu);
+
+ INIT_WORK(&device->rcu_work, __free_device);
+ schedule_work(&device->rcu_work);
+}
+
static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
{
struct btrfs_device *device;
if (--fs_devices->opened > 0)
return 0;
+ mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry(device, &fs_devices->devices, dev_list) {
- if (device->bdev) {
- blkdev_put(device->bdev, device->mode);
+ 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--;
}
- device->bdev = NULL;
- device->writeable = 0;
- device->in_fs_metadata = 0;
+ new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
+ BUG_ON(!new_device);
+ memcpy(new_device, device, sizeof(*new_device));
+ new_device->name = kstrdup(device->name, GFP_NOFS);
+ BUG_ON(!new_device->name);
+ new_device->bdev = NULL;
+ new_device->writeable = 0;
+ new_device->in_fs_metadata = 0;
+ list_replace_rcu(&device->dev_list, &new_device->dev_list);
+
+ call_rcu(&device->rcu, free_device);
}
+ mutex_unlock(&fs_devices->device_list_mutex);
+
WARN_ON(fs_devices->open_devices);
WARN_ON(fs_devices->rw_devices);
fs_devices->opened = 0;
list_add(&device->dev_alloc_list,
&fs_devices->alloc_list);
}
+ brelse(bh);
continue;
error_brelse:
if (ret > 0) {
ret = btrfs_previous_item(root, path, key.objectid,
BTRFS_DEV_EXTENT_KEY);
- BUG_ON(ret);
+ 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);
- ret = 0;
} else if (ret == 0) {
leaf = path->nodes[0];
extent = btrfs_item_ptr(leaf, path->slots[0],
if (device->bytes_used > 0)
device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
ret = btrfs_del_item(trans, root, path);
- BUG_ON(ret);
+out:
btrfs_free_path(path);
return ret;
}
struct block_device *bdev;
struct buffer_head *bh = NULL;
struct btrfs_super_block *disk_super;
+ struct btrfs_fs_devices *cur_devices;
u64 all_avail;
u64 devid;
u64 num_devices;
u8 *dev_uuid;
int ret = 0;
+ bool clear_super = false;
mutex_lock(&uuid_mutex);
mutex_lock(&root->fs_info->volume_mutex);
device = NULL;
devices = &root->fs_info->fs_devices->devices;
- mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
+ /*
+ * 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;
}
}
- mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
bdev = NULL;
bh = NULL;
disk_super = NULL;
}
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);
* 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_init(&device->dev_list);
- mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
+ list_del_rcu(&device->dev_list);
device->fs_devices->num_devices--;
if (device->bdev == root->fs_info->fs_devices->latest_bdev)
root->fs_info->fs_devices->latest_bdev = next_device->bdev;
- if (device->bdev) {
- blkdev_put(device->bdev, device->mode);
- device->bdev = NULL;
+ 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 (device->fs_devices->open_devices == 0) {
+ 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 == device->fs_devices)
+ if (fs_devices->seed == cur_devices)
break;
fs_devices = fs_devices->seed;
}
- fs_devices->seed = device->fs_devices->seed;
- device->fs_devices->seed = NULL;
- __btrfs_close_devices(device->fs_devices);
- free_fs_devices(device->fs_devices);
+ fs_devices->seed = cur_devices->seed;
+ cur_devices->seed = NULL;
+ lock_chunks(root);
+ __btrfs_close_devices(cur_devices);
+ unlock_chunks(root);
+ free_fs_devices(cur_devices);
}
/*
* at this point, the device is zero sized. We want to
* remove it from the devices list and zero out the old super
*/
- if (device->writeable) {
+ if (clear_super) {
/* make sure this device isn't detected as part of
* the FS anymore
*/
sync_dirty_buffer(bh);
}
- kfree(device->name);
- kfree(device);
ret = 0;
error_brelse:
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;
INIT_LIST_HEAD(&seed_devices->devices);
INIT_LIST_HEAD(&seed_devices->alloc_list);
mutex_init(&seed_devices->device_list_mutex);
- list_splice_init(&fs_devices->devices, &seed_devices->devices);
+
+ 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;
* half setup
*/
mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
- list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
+ 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++;
BUG_ON(ret);
ret = btrfs_del_item(trans, root, path);
- BUG_ON(ret);
btrfs_free_path(path);
- return 0;
+ return ret;
}
static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
git.openpandora.org / pandora-kernel.git / blobdiff