diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-02-09 14:58:11 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-02-09 14:58:11 +0100 |
commit | 249d51b53aea1b7cdb1be65a1a9a0c59d9e06f3e (patch) | |
tree | 7fc06930e46ee13d394f5b031166c40206af3189 /fs/btrfs/tree-log.c | |
parent | 44581a28e805a31661469c4b466b9cd14b36e7b6 (diff) | |
parent | 8e4921515c1a379539607eb443d51c30f4f7f338 (diff) |
Merge commit 'v2.6.29-rc4' into core/percpu
Conflicts:
arch/x86/mach-voyager/voyager_smp.c
arch/x86/mm/fault.c
Diffstat (limited to 'fs/btrfs/tree-log.c')
-rw-r--r-- | fs/btrfs/tree-log.c | 354 |
1 files changed, 170 insertions, 184 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index d81cda2e077..20794290256 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -78,104 +78,6 @@ static int link_to_fixup_dir(struct btrfs_trans_handle *trans, */ /* - * btrfs_add_log_tree adds a new per-subvolume log tree into the - * tree of log tree roots. This must be called with a tree log transaction - * running (see start_log_trans). - */ -static int btrfs_add_log_tree(struct btrfs_trans_handle *trans, - struct btrfs_root *root) -{ - struct btrfs_key key; - struct btrfs_root_item root_item; - struct btrfs_inode_item *inode_item; - struct extent_buffer *leaf; - struct btrfs_root *new_root = root; - int ret; - u64 objectid = root->root_key.objectid; - - leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0, - BTRFS_TREE_LOG_OBJECTID, - trans->transid, 0, 0, 0); - if (IS_ERR(leaf)) { - ret = PTR_ERR(leaf); - return ret; - } - - btrfs_set_header_nritems(leaf, 0); - btrfs_set_header_level(leaf, 0); - btrfs_set_header_bytenr(leaf, leaf->start); - btrfs_set_header_generation(leaf, trans->transid); - btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID); - - write_extent_buffer(leaf, root->fs_info->fsid, - (unsigned long)btrfs_header_fsid(leaf), - BTRFS_FSID_SIZE); - btrfs_mark_buffer_dirty(leaf); - - inode_item = &root_item.inode; - memset(inode_item, 0, sizeof(*inode_item)); - inode_item->generation = cpu_to_le64(1); - inode_item->size = cpu_to_le64(3); - inode_item->nlink = cpu_to_le32(1); - inode_item->nbytes = cpu_to_le64(root->leafsize); - inode_item->mode = cpu_to_le32(S_IFDIR | 0755); - - btrfs_set_root_bytenr(&root_item, leaf->start); - btrfs_set_root_generation(&root_item, trans->transid); - btrfs_set_root_level(&root_item, 0); - btrfs_set_root_refs(&root_item, 0); - btrfs_set_root_used(&root_item, 0); - - memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress)); - root_item.drop_level = 0; - - btrfs_tree_unlock(leaf); - free_extent_buffer(leaf); - leaf = NULL; - - btrfs_set_root_dirid(&root_item, 0); - - key.objectid = BTRFS_TREE_LOG_OBJECTID; - key.offset = objectid; - btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); - ret = btrfs_insert_root(trans, root->fs_info->log_root_tree, &key, - &root_item); - if (ret) - goto fail; - - new_root = btrfs_read_fs_root_no_radix(root->fs_info->log_root_tree, - &key); - BUG_ON(!new_root); - - WARN_ON(root->log_root); - root->log_root = new_root; - - /* - * log trees do not get reference counted because they go away - * before a real commit is actually done. They do store pointers - * to file data extents, and those reference counts still get - * updated (along with back refs to the log tree). - */ - new_root->ref_cows = 0; - new_root->last_trans = trans->transid; - - /* - * we need to make sure the root block for this new tree - * is marked as dirty in the dirty_log_pages tree. This - * is how it gets flushed down to disk at tree log commit time. - * - * the tree logging mutex keeps others from coming in and changing - * the new_root->node, so we can safely access it here - */ - set_extent_dirty(&new_root->dirty_log_pages, new_root->node->start, - new_root->node->start + new_root->node->len - 1, - GFP_NOFS); - -fail: - return ret; -} - -/* * start a sub transaction and setup the log tree * this increments the log tree writer count to make the people * syncing the tree wait for us to finish @@ -184,6 +86,14 @@ static int start_log_trans(struct btrfs_trans_handle *trans, struct btrfs_root *root) { int ret; + + mutex_lock(&root->log_mutex); + if (root->log_root) { + root->log_batch++; + atomic_inc(&root->log_writers); + mutex_unlock(&root->log_mutex); + return 0; + } mutex_lock(&root->fs_info->tree_log_mutex); if (!root->fs_info->log_root_tree) { ret = btrfs_init_log_root_tree(trans, root->fs_info); @@ -193,9 +103,10 @@ static int start_log_trans(struct btrfs_trans_handle *trans, ret = btrfs_add_log_tree(trans, root); BUG_ON(ret); } - atomic_inc(&root->fs_info->tree_log_writers); - root->fs_info->tree_log_batch++; mutex_unlock(&root->fs_info->tree_log_mutex); + root->log_batch++; + atomic_inc(&root->log_writers); + mutex_unlock(&root->log_mutex); return 0; } @@ -212,13 +123,12 @@ static int join_running_log_trans(struct btrfs_root *root) if (!root->log_root) return -ENOENT; - mutex_lock(&root->fs_info->tree_log_mutex); + mutex_lock(&root->log_mutex); if (root->log_root) { ret = 0; - atomic_inc(&root->fs_info->tree_log_writers); - root->fs_info->tree_log_batch++; + atomic_inc(&root->log_writers); } - mutex_unlock(&root->fs_info->tree_log_mutex); + mutex_unlock(&root->log_mutex); return ret; } @@ -228,10 +138,11 @@ static int join_running_log_trans(struct btrfs_root *root) */ static int end_log_trans(struct btrfs_root *root) { - atomic_dec(&root->fs_info->tree_log_writers); - smp_mb(); - if (waitqueue_active(&root->fs_info->tree_log_wait)) - wake_up(&root->fs_info->tree_log_wait); + if (atomic_dec_and_test(&root->log_writers)) { + smp_mb(); + if (waitqueue_active(&root->log_writer_wait)) + wake_up(&root->log_writer_wait); + } return 0; } @@ -1704,6 +1615,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans, btrfs_tree_lock(next); clean_tree_block(trans, root, next); + btrfs_set_lock_blocking(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); @@ -1750,6 +1662,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans, next = path->nodes[*level]; btrfs_tree_lock(next); clean_tree_block(trans, root, next); + btrfs_set_lock_blocking(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); @@ -1807,6 +1720,7 @@ static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans, btrfs_tree_lock(next); clean_tree_block(trans, root, next); + btrfs_set_lock_blocking(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); @@ -1879,6 +1793,7 @@ static int walk_log_tree(struct btrfs_trans_handle *trans, btrfs_tree_lock(next); clean_tree_block(trans, log, next); + btrfs_set_lock_blocking(next); btrfs_wait_tree_block_writeback(next); btrfs_tree_unlock(next); @@ -1902,26 +1817,65 @@ static int walk_log_tree(struct btrfs_trans_handle *trans, } } btrfs_free_path(path); - if (wc->free) - free_extent_buffer(log->node); return ret; } -static int wait_log_commit(struct btrfs_root *log) +/* + * helper function to update the item for a given subvolumes log root + * in the tree of log roots + */ +static int update_log_root(struct btrfs_trans_handle *trans, + struct btrfs_root *log) +{ + int ret; + + if (log->log_transid == 1) { + /* insert root item on the first sync */ + ret = btrfs_insert_root(trans, log->fs_info->log_root_tree, + &log->root_key, &log->root_item); + } else { + ret = btrfs_update_root(trans, log->fs_info->log_root_tree, + &log->root_key, &log->root_item); + } + return ret; +} + +static int wait_log_commit(struct btrfs_root *root, unsigned long transid) { DEFINE_WAIT(wait); - u64 transid = log->fs_info->tree_log_transid; + int index = transid % 2; + /* + * we only allow two pending log transactions at a time, + * so we know that if ours is more than 2 older than the + * current transaction, we're done + */ do { - prepare_to_wait(&log->fs_info->tree_log_wait, &wait, - TASK_UNINTERRUPTIBLE); - mutex_unlock(&log->fs_info->tree_log_mutex); - if (atomic_read(&log->fs_info->tree_log_commit)) + prepare_to_wait(&root->log_commit_wait[index], + &wait, TASK_UNINTERRUPTIBLE); + mutex_unlock(&root->log_mutex); + if (root->log_transid < transid + 2 && + atomic_read(&root->log_commit[index])) schedule(); - finish_wait(&log->fs_info->tree_log_wait, &wait); - mutex_lock(&log->fs_info->tree_log_mutex); - } while (transid == log->fs_info->tree_log_transid && - atomic_read(&log->fs_info->tree_log_commit)); + finish_wait(&root->log_commit_wait[index], &wait); + mutex_lock(&root->log_mutex); + } while (root->log_transid < transid + 2 && + atomic_read(&root->log_commit[index])); + return 0; +} + +static int wait_for_writer(struct btrfs_root *root) +{ + DEFINE_WAIT(wait); + while (atomic_read(&root->log_writers)) { + prepare_to_wait(&root->log_writer_wait, + &wait, TASK_UNINTERRUPTIBLE); + mutex_unlock(&root->log_mutex); + if (atomic_read(&root->log_writers)) + schedule(); + mutex_lock(&root->log_mutex); + finish_wait(&root->log_writer_wait, &wait); + } return 0; } @@ -1933,57 +1887,114 @@ static int wait_log_commit(struct btrfs_root *log) int btrfs_sync_log(struct btrfs_trans_handle *trans, struct btrfs_root *root) { + int index1; + int index2; int ret; - unsigned long batch; struct btrfs_root *log = root->log_root; + struct btrfs_root *log_root_tree = root->fs_info->log_root_tree; - mutex_lock(&log->fs_info->tree_log_mutex); - if (atomic_read(&log->fs_info->tree_log_commit)) { - wait_log_commit(log); - goto out; + mutex_lock(&root->log_mutex); + index1 = root->log_transid % 2; + if (atomic_read(&root->log_commit[index1])) { + wait_log_commit(root, root->log_transid); + mutex_unlock(&root->log_mutex); + return 0; } - atomic_set(&log->fs_info->tree_log_commit, 1); + atomic_set(&root->log_commit[index1], 1); + + /* wait for previous tree log sync to complete */ + if (atomic_read(&root->log_commit[(index1 + 1) % 2])) + wait_log_commit(root, root->log_transid - 1); while (1) { - batch = log->fs_info->tree_log_batch; - mutex_unlock(&log->fs_info->tree_log_mutex); + unsigned long batch = root->log_batch; + mutex_unlock(&root->log_mutex); schedule_timeout_uninterruptible(1); - mutex_lock(&log->fs_info->tree_log_mutex); - - while (atomic_read(&log->fs_info->tree_log_writers)) { - DEFINE_WAIT(wait); - prepare_to_wait(&log->fs_info->tree_log_wait, &wait, - TASK_UNINTERRUPTIBLE); - mutex_unlock(&log->fs_info->tree_log_mutex); - if (atomic_read(&log->fs_info->tree_log_writers)) - schedule(); - mutex_lock(&log->fs_info->tree_log_mutex); - finish_wait(&log->fs_info->tree_log_wait, &wait); - } - if (batch == log->fs_info->tree_log_batch) + mutex_lock(&root->log_mutex); + wait_for_writer(root); + if (batch == root->log_batch) break; } ret = btrfs_write_and_wait_marked_extents(log, &log->dirty_log_pages); BUG_ON(ret); - ret = btrfs_write_and_wait_marked_extents(root->fs_info->log_root_tree, - &root->fs_info->log_root_tree->dirty_log_pages); + + btrfs_set_root_bytenr(&log->root_item, log->node->start); + btrfs_set_root_generation(&log->root_item, trans->transid); + btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node)); + + root->log_batch = 0; + root->log_transid++; + log->log_transid = root->log_transid; + smp_mb(); + /* + * log tree has been flushed to disk, new modifications of + * the log will be written to new positions. so it's safe to + * allow log writers to go in. + */ + mutex_unlock(&root->log_mutex); + + mutex_lock(&log_root_tree->log_mutex); + log_root_tree->log_batch++; + atomic_inc(&log_root_tree->log_writers); + mutex_unlock(&log_root_tree->log_mutex); + + ret = update_log_root(trans, log); + BUG_ON(ret); + + mutex_lock(&log_root_tree->log_mutex); + if (atomic_dec_and_test(&log_root_tree->log_writers)) { + smp_mb(); + if (waitqueue_active(&log_root_tree->log_writer_wait)) + wake_up(&log_root_tree->log_writer_wait); + } + + index2 = log_root_tree->log_transid % 2; + if (atomic_read(&log_root_tree->log_commit[index2])) { + wait_log_commit(log_root_tree, log_root_tree->log_transid); + mutex_unlock(&log_root_tree->log_mutex); + goto out; + } + atomic_set(&log_root_tree->log_commit[index2], 1); + + if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) + wait_log_commit(log_root_tree, log_root_tree->log_transid - 1); + + wait_for_writer(log_root_tree); + + ret = btrfs_write_and_wait_marked_extents(log_root_tree, + &log_root_tree->dirty_log_pages); BUG_ON(ret); btrfs_set_super_log_root(&root->fs_info->super_for_commit, - log->fs_info->log_root_tree->node->start); + log_root_tree->node->start); btrfs_set_super_log_root_level(&root->fs_info->super_for_commit, - btrfs_header_level(log->fs_info->log_root_tree->node)); + btrfs_header_level(log_root_tree->node)); + + log_root_tree->log_batch = 0; + log_root_tree->log_transid++; + smp_mb(); + + mutex_unlock(&log_root_tree->log_mutex); + + /* + * nobody else is going to jump in and write the the ctree + * super here because the log_commit atomic below is protecting + * us. We must be called with a transaction handle pinning + * the running transaction open, so a full commit can't hop + * in and cause problems either. + */ + write_ctree_super(trans, root->fs_info->tree_root, 2); - write_ctree_super(trans, log->fs_info->tree_root, 2); - log->fs_info->tree_log_transid++; - log->fs_info->tree_log_batch = 0; - atomic_set(&log->fs_info->tree_log_commit, 0); + atomic_set(&log_root_tree->log_commit[index2], 0); smp_mb(); - if (waitqueue_active(&log->fs_info->tree_log_wait)) - wake_up(&log->fs_info->tree_log_wait); + if (waitqueue_active(&log_root_tree->log_commit_wait[index2])) + wake_up(&log_root_tree->log_commit_wait[index2]); out: - mutex_unlock(&log->fs_info->tree_log_mutex); + atomic_set(&root->log_commit[index1], 0); + smp_mb(); + if (waitqueue_active(&root->log_commit_wait[index1])) + wake_up(&root->log_commit_wait[index1]); return 0; } @@ -2019,38 +2030,18 @@ int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root) start, end, GFP_NOFS); } - log = root->log_root; - ret = btrfs_del_root(trans, root->fs_info->log_root_tree, - &log->root_key); - BUG_ON(ret); + if (log->log_transid > 0) { + ret = btrfs_del_root(trans, root->fs_info->log_root_tree, + &log->root_key); + BUG_ON(ret); + } root->log_root = NULL; - kfree(root->log_root); + free_extent_buffer(log->node); + kfree(log); return 0; } /* - * helper function to update the item for a given subvolumes log root - * in the tree of log roots - */ -static int update_log_root(struct btrfs_trans_handle *trans, - struct btrfs_root *log) -{ - u64 bytenr = btrfs_root_bytenr(&log->root_item); - int ret; - - if (log->node->start == bytenr) - return 0; - - btrfs_set_root_bytenr(&log->root_item, log->node->start); - btrfs_set_root_generation(&log->root_item, trans->transid); - btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node)); - ret = btrfs_update_root(trans, log->fs_info->log_root_tree, - &log->root_key, &log->root_item); - BUG_ON(ret); - return ret; -} - -/* * If both a file and directory are logged, and unlinks or renames are * mixed in, we have a few interesting corners: * @@ -2711,11 +2702,6 @@ next_slot: btrfs_free_path(path); btrfs_free_path(dst_path); - - mutex_lock(&root->fs_info->tree_log_mutex); - ret = update_log_root(trans, log); - BUG_ON(ret); - mutex_unlock(&root->fs_info->tree_log_mutex); out: return 0; } |