diff options
| -rw-r--r-- | fs/btrfs/ctree.h | 6 | ||||
| -rw-r--r-- | fs/btrfs/dev-replace.c | 130 | ||||
| -rw-r--r-- | fs/btrfs/dev-replace.h | 7 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.c | 6 | ||||
| -rw-r--r-- | fs/btrfs/reada.c | 10 | ||||
| -rw-r--r-- | fs/btrfs/scrub.c | 6 | ||||
| -rw-r--r-- | fs/btrfs/volumes.c | 24 |
7 files changed, 105 insertions, 84 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index bfe4a337fb4d..0b427a6966ad 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1002,8 +1002,10 @@ struct btrfs_dev_replace { pid_t lock_owner; atomic_t nesting_level; struct mutex lock_finishing_cancel_unmount; - struct mutex lock_management_lock; - struct mutex lock; + rwlock_t lock; + atomic_t read_locks; + atomic_t blocking_readers; + wait_queue_head_t read_lock_wq; struct btrfs_scrub_progress scrub_progress; }; diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index cbb7dbfb3fff..8c8b48971bc7 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -202,13 +202,13 @@ int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, struct btrfs_dev_replace_item *ptr; struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 0); if (!dev_replace->is_valid || !dev_replace->item_needs_writeback) { - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 0); return 0; } - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 0); key.objectid = 0; key.type = BTRFS_DEV_REPLACE_KEY; @@ -264,7 +264,7 @@ int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_replace_item); - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 1); if (dev_replace->srcdev) btrfs_set_dev_replace_src_devid(eb, ptr, dev_replace->srcdev->devid); @@ -287,7 +287,7 @@ int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, btrfs_set_dev_replace_cursor_right(eb, ptr, dev_replace->cursor_right); dev_replace->item_needs_writeback = 0; - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); btrfs_mark_buffer_dirty(eb); @@ -356,7 +356,7 @@ int btrfs_dev_replace_start(struct btrfs_root *root, return PTR_ERR(trans); } - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 1); switch (dev_replace->replace_state) { case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: @@ -395,7 +395,7 @@ int btrfs_dev_replace_start(struct btrfs_root *root, dev_replace->is_valid = 1; dev_replace->item_needs_writeback = 1; args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); if (ret) @@ -407,7 +407,7 @@ int btrfs_dev_replace_start(struct btrfs_root *root, trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 1); goto leave; } @@ -433,7 +433,7 @@ int btrfs_dev_replace_start(struct btrfs_root *root, leave: dev_replace->srcdev = NULL; dev_replace->tgtdev = NULL; - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device); return ret; } @@ -471,18 +471,18 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, /* don't allow cancel or unmount to disturb the finishing procedure */ mutex_lock(&dev_replace->lock_finishing_cancel_unmount); - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 0); /* was the operation canceled, or is it finished? */ if (dev_replace->replace_state != BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) { - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 0); mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); return 0; } tgt_device = dev_replace->tgtdev; src_device = dev_replace->srcdev; - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 0); /* * flush all outstanding I/O and inode extent mappings before the @@ -507,7 +507,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, /* keep away write_all_supers() during the finishing procedure */ mutex_lock(&root->fs_info->fs_devices->device_list_mutex); mutex_lock(&root->fs_info->chunk_mutex); - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 1); dev_replace->replace_state = scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED; @@ -528,7 +528,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, rcu_str_deref(src_device->name), src_device->devid, rcu_str_deref(tgt_device->name), scrub_ret); - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); mutex_unlock(&root->fs_info->chunk_mutex); mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); mutex_unlock(&uuid_mutex); @@ -565,7 +565,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list); fs_info->fs_devices->rw_devices++; - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); btrfs_rm_dev_replace_blocked(fs_info); @@ -649,7 +649,7 @@ void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; struct btrfs_device *srcdev; - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 0); /* even if !dev_replace_is_valid, the values are good enough for * the replace_status ioctl */ args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; @@ -675,7 +675,7 @@ void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, div_u64(btrfs_device_get_total_bytes(srcdev), 1000)); break; } - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 0); } int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, @@ -698,13 +698,13 @@ static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) return -EROFS; mutex_lock(&dev_replace->lock_finishing_cancel_unmount); - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 1); switch (dev_replace->replace_state) { case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED; - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); goto leave; case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: @@ -717,7 +717,7 @@ static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED; dev_replace->time_stopped = get_seconds(); dev_replace->item_needs_writeback = 1; - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); btrfs_scrub_cancel(fs_info); trans = btrfs_start_transaction(root, 0); @@ -740,7 +740,7 @@ void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; mutex_lock(&dev_replace->lock_finishing_cancel_unmount); - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 1); switch (dev_replace->replace_state) { case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: @@ -756,7 +756,7 @@ void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) break; } - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); mutex_unlock(&dev_replace->lock_finishing_cancel_unmount); } @@ -766,12 +766,12 @@ int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) struct task_struct *task; struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 1); switch (dev_replace->replace_state) { case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED: case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED: - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); return 0; case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: break; @@ -784,10 +784,10 @@ int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) btrfs_info(fs_info, "cannot continue dev_replace, tgtdev is missing"); btrfs_info(fs_info, "you may cancel the operation after 'mount -o degraded'"); - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); return 0; } - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 1); WARN_ON(atomic_xchg( &fs_info->mutually_exclusive_operation_running, 1)); @@ -865,48 +865,58 @@ int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) return 1; } -void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace) +void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw) { - /* the beginning is just an optimization for the typical case */ - if (atomic_read(&dev_replace->nesting_level) == 0) { -acquire_lock: - /* this is not a nested case where the same thread - * is trying to acqurire the same lock twice */ - mutex_lock(&dev_replace->lock); - mutex_lock(&dev_replace->lock_management_lock); - dev_replace->lock_owner = current->pid; - atomic_inc(&dev_replace->nesting_level); - mutex_unlock(&dev_replace->lock_management_lock); - return; + if (rw == 1) { + /* write */ +again: + wait_event(dev_replace->read_lock_wq, + atomic_read(&dev_replace->blocking_readers) == 0); + write_lock(&dev_replace->lock); + if (atomic_read(&dev_replace->blocking_readers)) { + write_unlock(&dev_replace->lock); + goto again; + } + } else { + read_lock(&dev_replace->lock); + atomic_inc(&dev_replace->read_locks); } +} - mutex_lock(&dev_replace->lock_management_lock); - if (atomic_read(&dev_replace->nesting_level) > 0 && - dev_replace->lock_owner == current->pid) { - WARN_ON(!mutex_is_locked(&dev_replace->lock)); - atomic_inc(&dev_replace->nesting_level); - mutex_unlock(&dev_replace->lock_management_lock); - return; +void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw) +{ + if (rw == 1) { + /* write */ + ASSERT(atomic_read(&dev_replace->blocking_readers) == 0); + write_unlock(&dev_replace->lock); + } else { + ASSERT(atomic_read(&dev_replace->read_locks) > 0); + atomic_dec(&dev_replace->read_locks); + read_unlock(&dev_replace->lock); } +} - mutex_unlock(&dev_replace->lock_management_lock); - goto acquire_lock; +/* inc blocking cnt and release read lock */ +void btrfs_dev_replace_set_lock_blocking( + struct btrfs_dev_replace *dev_replace) +{ + /* only set blocking for read lock */ + ASSERT(atomic_read(&dev_replace->read_locks) > 0); + atomic_inc(&dev_replace->blocking_readers); + read_unlock(&dev_replace->lock); } -void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace) +/* acquire read lock and dec blocking cnt */ +void btrfs_dev_replace_clear_lock_blocking( + struct btrfs_dev_replace *dev_replace) { - WARN_ON(!mutex_is_locked(&dev_replace->lock)); - mutex_lock(&dev_replace->lock_management_lock); - WARN_ON(atomic_read(&dev_replace->nesting_level) < 1); - WARN_ON(dev_replace->lock_owner != current->pid); - atomic_dec(&dev_replace->nesting_level); - if (atomic_read(&dev_replace->nesting_level) == 0) { - dev_replace->lock_owner = 0; - mutex_unlock(&dev_replace->lock_management_lock); - mutex_unlock(&dev_replace->lock); - } else { - mutex_unlock(&dev_replace->lock_management_lock); - } + /* only set blocking for read lock */ + ASSERT(atomic_read(&dev_replace->read_locks) > 0); + ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); + read_lock(&dev_replace->lock); + if (atomic_dec_and_test(&dev_replace->blocking_readers) && + waitqueue_active(&dev_replace->read_lock_wq)) + wake_up(&dev_replace->read_lock_wq); } void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h index 20035cbbf021..29e3ef5f96bd 100644 --- a/fs/btrfs/dev-replace.h +++ b/fs/btrfs/dev-replace.h @@ -34,8 +34,11 @@ int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info, void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info); int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info); int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace); -void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace); -void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace); +void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw); +void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw); +void btrfs_dev_replace_set_lock_blocking(struct btrfs_dev_replace *dev_replace); +void btrfs_dev_replace_clear_lock_blocking( + struct btrfs_dev_replace *dev_replace); static inline void btrfs_dev_replace_stats_inc(atomic64_t *stat_value) { diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 4545e2e2ad45..81d0f39c2266 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2272,9 +2272,11 @@ static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info) fs_info->dev_replace.lock_owner = 0; atomic_set(&fs_info->dev_replace.nesting_level, 0); mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount); - mutex_init(&fs_info->dev_replace.lock_management_lock); - mutex_init(&fs_info->dev_replace.lock); + rwlock_init(&fs_info->dev_replace.lock); + atomic_set(&fs_info->dev_replace.read_locks, 0); + atomic_set(&fs_info->dev_replace.blocking_readers, 0); init_waitqueue_head(&fs_info->replace_wait); + init_waitqueue_head(&fs_info->dev_replace.read_lock_wq); } static void btrfs_init_qgroup(struct btrfs_fs_info *fs_info) diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c index 619f92963e27..fe3d4c7b6342 100644 --- a/fs/btrfs/reada.c +++ b/fs/btrfs/reada.c @@ -396,7 +396,7 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root, } /* insert extent in reada_tree + all per-device trees, all or nothing */ - btrfs_dev_replace_lock(&fs_info->dev_replace); + btrfs_dev_replace_lock(&fs_info->dev_replace, 0); spin_lock(&fs_info->reada_lock); ret = radix_tree_insert(&fs_info->reada_tree, index, re); if (ret == -EEXIST) { @@ -404,12 +404,12 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root, BUG_ON(!re_exist); re_exist->refcnt++; spin_unlock(&fs_info->reada_lock); - btrfs_dev_replace_unlock(&fs_info->dev_replace); + btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); goto error; } if (ret) { spin_unlock(&fs_info->reada_lock); - btrfs_dev_replace_unlock(&fs_info->dev_replace); + btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); goto error; } prev_dev = NULL; @@ -456,12 +456,12 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root, BUG_ON(fs_info == NULL); radix_tree_delete(&fs_info->reada_tree, index); spin_unlock(&fs_info->reada_lock); - btrfs_dev_replace_unlock(&fs_info->dev_replace); + btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); goto error; } } spin_unlock(&fs_info->reada_lock); - btrfs_dev_replace_unlock(&fs_info->dev_replace); + btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); btrfs_put_bbio(bbio); return re; diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 92bf5ee732fb..4151792ff556 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -3857,16 +3857,16 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, return -EIO; } - btrfs_dev_replace_lock(&fs_info->dev_replace); + btrfs_dev_replace_lock(&fs_info->dev_replace, 0); if (dev->scrub_device || (!is_dev_replace && btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) { - btrfs_dev_replace_unlock(&fs_info->dev_replace); + btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); mutex_unlock(&fs_info->scrub_lock); mutex_unlock(&fs_info->fs_devices->device_list_mutex); return -EINPROGRESS; } - btrfs_dev_replace_unlock(&fs_info->dev_replace); + btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); ret = scrub_workers_get(fs_info, is_dev_replace); if (ret) { diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 366b335946fa..858a2e489977 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1714,12 +1714,12 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path) } while (read_seqretry(&root->fs_info->profiles_lock, seq)); num_devices = root->fs_info->fs_devices->num_devices; - btrfs_dev_replace_lock(&root->fs_info->dev_replace); + btrfs_dev_replace_lock(&root->fs_info->dev_replace, 0); if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) { WARN_ON(num_devices < 1); num_devices--; } - btrfs_dev_replace_unlock(&root->fs_info->dev_replace); + btrfs_dev_replace_unlock(&root->fs_info->dev_replace, 0); if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) { ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET; @@ -3686,12 +3686,12 @@ int btrfs_balance(struct btrfs_balance_control *bctl, } num_devices = fs_info->fs_devices->num_devices; - btrfs_dev_replace_lock(&fs_info->dev_replace); + btrfs_dev_replace_lock(&fs_info->dev_replace, 0); if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) { BUG_ON(num_devices < 1); num_devices--; } - btrfs_dev_replace_unlock(&fs_info->dev_replace); + btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE; if (num_devices == 1) allowed |= BTRFS_BLOCK_GROUP_DUP; @@ -5062,10 +5062,10 @@ int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) ret = 1; free_extent_map(em); - btrfs_dev_replace_lock(&fs_info->dev_replace); + btrfs_dev_replace_lock(&fs_info->dev_replace, 0); if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) ret++; - btrfs_dev_replace_unlock(&fs_info->dev_replace); + btrfs_dev_replace_unlock(&fs_info->dev_replace, 0); return ret; } @@ -5325,10 +5325,12 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, if (!bbio_ret) goto out; - btrfs_dev_replace_lock(dev_replace); + btrfs_dev_replace_lock(dev_replace, 0); dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace); if (!dev_replace_is_ongoing) - btrfs_dev_replace_unlock(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 0); + else + btrfs_dev_replace_set_lock_blocking(dev_replace); if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 && !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) && @@ -5751,8 +5753,10 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw, bbio->mirror_num = map->num_stripes + 1; } out: - if (dev_replace_is_ongoing) - btrfs_dev_replace_unlock(dev_replace); + if (dev_replace_is_ongoing) { + btrfs_dev_replace_clear_lock_blocking(dev_replace); + btrfs_dev_replace_unlock(dev_replace, 0); + } free_extent_map(em); return ret; } |