Btrfs devel - Nov 2009 - [PATCH 05/12] Btrfs: Avoid orphan inodes cleanup during replaying log

We do log replay in a single transaction, so it''s not good to
do unbound operations during replaying log. This patch makes
orphan inodes cleanup executed after replaying log. It also
avoid doing other unbound operations such as truncating a file
during replaying log. These unbound operations are postponed
to the orphan inode cleanup stage.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
---
 fs/btrfs/ctree.h      |    5 +++--
 fs/btrfs/disk-io.c    |   17 +++++++++++------
 fs/btrfs/inode.c      |   19 ++++++++++++++++---
 fs/btrfs/relocation.c |    1 +
 fs/btrfs/tree-log.c   |   49 ++++++++++++++++++++++++-------------------------
 5 files changed, 55 insertions(+), 36 deletions(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index f6ad2d5..ec7884c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -859,8 +859,9 @@ struct btrfs_fs_info {
 	struct mutex ordered_operations_mutex;
 	struct rw_semaphore extent_commit_sem;
 
-	struct rw_semaphore subvol_sem;
+	struct rw_semaphore cleanup_work_sem;
 
+	struct rw_semaphore subvol_sem;
 	struct srcu_struct subvol_srcu;
 
 	struct list_head trans_list;
@@ -1034,12 +1035,12 @@ struct btrfs_root {
 	int ref_cows;
 	int track_dirty;
 	int in_radix;
+	int clean_orphans;
 
 	u64 defrag_trans_start;
 	struct btrfs_key defrag_progress;
 	struct btrfs_key defrag_max;
 	int defrag_running;
-	int defrag_level;
 	char *name;
 	int in_sysfs;
 
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 0cf1781..e2ebc47 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -894,6 +894,8 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32
sectorsize,
 	root->stripesize = stripesize;
 	root->ref_cows = 0;
 	root->track_dirty = 0;
+	root->in_radix = 0;
+	root->clean_orphans = 0;
 
 	root->fs_info = fs_info;
 	root->objectid = objectid;
@@ -930,7 +932,6 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32
sectorsize,
 	root->defrag_trans_start = fs_info->generation;
 	init_completion(&root->kobj_unregister);
 	root->defrag_running = 0;
-	root->defrag_level = 0;
 	root->root_key.objectid = objectid;
 	root->anon_super.s_root = NULL;
 	root->anon_super.s_dev = 0;
@@ -1212,8 +1213,10 @@ again:
 	ret = radix_tree_insert(&fs_info->fs_roots_radix,
 				(unsigned long)root->root_key.objectid,
 				root);
-	if (ret == 0)
+	if (ret == 0) {
 		root->in_radix = 1;
+		root->clean_orphans = 1;
+	}
 	spin_unlock(&fs_info->fs_roots_radix_lock);
 	radix_tree_preload_end();
 	if (ret) {
@@ -1227,10 +1230,6 @@ again:
 	ret = btrfs_find_dead_roots(fs_info->tree_root,
 				    root->root_key.objectid);
 	WARN_ON(ret);
-
-	if (!(fs_info->sb->s_flags & MS_RDONLY))
-		btrfs_orphan_cleanup(root);
-
 	return root;
 fail:
 	free_fs_root(root);
@@ -1689,6 +1688,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	mutex_init(&fs_info->cleaner_mutex);
 	mutex_init(&fs_info->volume_mutex);
 	init_rwsem(&fs_info->extent_commit_sem);
+	init_rwsem(&fs_info->cleanup_work_sem);
 	init_rwsem(&fs_info->subvol_sem);
 
 	btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
@@ -2388,6 +2388,11 @@ int btrfs_commit_super(struct btrfs_root *root)
 	mutex_lock(&root->fs_info->cleaner_mutex);
 	btrfs_clean_old_snapshots(root);
 	mutex_unlock(&root->fs_info->cleaner_mutex);
+
+	/* wait until ongoing cleanup work done */
+	down_write(&root->fs_info->cleanup_work_sem);
+	up_write(&root->fs_info->cleanup_work_sem);
+
 	trans = btrfs_start_transaction(root, 1);
 	ret = btrfs_commit_transaction(trans, root);
 	BUG_ON(ret);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index a824372..75a6647 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2088,16 +2088,17 @@ void btrfs_orphan_cleanup(struct btrfs_root *root)
 	struct inode *inode;
 	int ret = 0, nr_unlink = 0, nr_truncate = 0;
 
-	path = btrfs_alloc_path();
-	if (!path)
+	if (!xchg(&root->clean_orphans, 0))
 		return;
+
+	path = btrfs_alloc_path();
+	BUG_ON(!path);
 	path->reada = -1;
 
 	key.objectid = BTRFS_ORPHAN_OBJECTID;
 	btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
 	key.offset = (u64)-1;
 
-
 	while (1) {
 		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 		if (ret < 0) {
@@ -3293,6 +3294,11 @@ void btrfs_delete_inode(struct inode *inode)
 	}
 	btrfs_wait_ordered_range(inode, 0, (u64)-1);
 
+	if (root->fs_info->log_root_recovering) {
+		BUG_ON(!list_empty(&BTRFS_I(inode)->i_orphan));
+		goto no_delete;
+	}
+
 	if (inode->i_nlink > 0) {
 		BUG_ON(btrfs_root_refs(&root->root_item) != 0);
 		goto no_delete;
@@ -3700,6 +3706,13 @@ struct inode *btrfs_lookup_dentry(struct inode *dir,
struct dentry *dentry)
 	}
 	srcu_read_unlock(&root->fs_info->subvol_srcu, index);
 
+	if (root != sub_root) {
+		down_read(&root->fs_info->cleanup_work_sem);
+		if (!(inode->i_sb->s_flags & MS_RDONLY))
+			btrfs_orphan_cleanup(sub_root);
+		up_read(&root->fs_info->cleanup_work_sem);
+	}
+
 	return inode;
 }
 
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index cfcc93c..975fdd3 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -3755,6 +3755,7 @@ out:
 				       BTRFS_DATA_RELOC_TREE_OBJECTID);
 		if (IS_ERR(fs_root))
 			err = PTR_ERR(fs_root);
+		btrfs_orphan_cleanup(fs_root);
 	}
 	return err;
 }
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index ce39fe6..9c0dc10 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -930,6 +930,17 @@ out_nowrite:
 	return 0;
 }
 
+static int insert_orphan_item(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root, u64 offset)
+{
+	int ret;
+	ret = btrfs_find_orphan_item(root, offset);
+	if (ret > 0)
+		ret = btrfs_insert_orphan_item(trans, root, offset);
+	return ret;
+}
+
+
 /*
  * There are a few corners where the link count of the file can''t
  * be properly maintained during replay.  So, instead of adding
@@ -997,9 +1008,13 @@ static noinline int fixup_inode_link_count(struct
btrfs_trans_handle *trans,
 	}
 	BTRFS_I(inode)->index_cnt = (u64)-1;
 
-	if (inode->i_nlink == 0 && S_ISDIR(inode->i_mode)) {
-		ret = replay_dir_deletes(trans, root, NULL, path,
-					 inode->i_ino, 1);
+	if (inode->i_nlink == 0) {
+		if (S_ISDIR(inode->i_mode)) {
+			ret = replay_dir_deletes(trans, root, NULL, path,
+						 inode->i_ino, 1);
+			BUG_ON(ret);
+		}
+		ret = insert_orphan_item(trans, root, inode->i_ino);
 		BUG_ON(ret);
 	}
 	btrfs_free_path(path);
@@ -1587,7 +1602,6 @@ static int replay_one_buffer(struct btrfs_root *log,
struct extent_buffer *eb,
 		/* inode keys are done during the first stage */
 		if (key.type == BTRFS_INODE_ITEM_KEY &&
 		    wc->stage == LOG_WALK_REPLAY_INODES) {
-			struct inode *inode;
 			struct btrfs_inode_item *inode_item;
 			u32 mode;
 
@@ -1603,31 +1617,16 @@ static int replay_one_buffer(struct btrfs_root *log,
struct extent_buffer *eb,
 					     eb, i, &key);
 			BUG_ON(ret);
 
-			/* for regular files, truncate away
-			 * extents past the new EOF
+			/* for regular files, make sure corresponding
+			 * orhpan item exist. extents past the new EOF
+			 * will be truncated later by orphan cleanup.
 			 */
 			if (S_ISREG(mode)) {
-				inode = read_one_inode(root,
-						       key.objectid);
-				BUG_ON(!inode);
-
-				ret = btrfs_truncate_inode_items(wc->trans,
-					root, inode, inode->i_size,
-					BTRFS_EXTENT_DATA_KEY);
+				ret = insert_orphan_item(wc->trans, root,
+							 key.objectid);
 				BUG_ON(ret);
-
-				/* if the nlink count is zero here, the iput
-				 * will free the inode.  We bump it to make
-				 * sure it doesn''t get freed until the link
-				 * count fixup is done
-				 */
-				if (inode->i_nlink == 0) {
-					btrfs_inc_nlink(inode);
-					btrfs_update_inode(wc->trans,
-							   root, inode);
-				}
-				iput(inode);
 			}
+
 			ret = link_to_fixup_dir(wc->trans, root,
 						path, key.objectid);
 			BUG_ON(ret);
-- 
1.6.2.5

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