btrfs: temporarily export and then move extent state helpers

In order to avoid moving all of the related code at once temporarily
export all of the extent state related helpers.  Then move these helpers
into extent-io-tree.c.  We will clean up the exports and make them
static in followup patches.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

3 files changed, 267 insertions, 258 deletions

diff --git a/fs/btrfs/extent-io-tree.c b/fs/btrfs/extent-io-tree.c
index 8dd03ac86d26..0afca10dc0f2 100644
--- a/fs/btrfs/extent-io-tree.c
+++ b/fs/btrfs/extent-io-tree.c
@@ -161,6 +161,24 @@ void free_extent_state(struct extent_state *state)
 	}
 }
 
+static int add_extent_changeset(struct extent_state *state, u32 bits,
+				 struct extent_changeset *changeset,
+				 int set)
+{
+	int ret;
+
+	if (!changeset)
+		return 0;
+	if (set && (state->state & bits) == bits)
+		return 0;
+	if (!set && (state->state & bits) == 0)
+		return 0;
+	changeset->bytes_changed += state->end - state->start + 1;
+	ret = ulist_add(&changeset->range_changed, state->start, state->end,
+			GFP_ATOMIC);
+	return ret;
+}
+
 /*
  * Search @tree for an entry that contains @offset. Such entry would have
  * entry->start <= offset && entry->end >= offset.
@@ -268,6 +286,229 @@ struct rb_node *tree_search_prev_next(struct extent_io_tree *tree, u64 offset,
 	return NULL;
 }
 
+/*
+ * Utility function to look for merge candidates inside a given range.  Any
+ * extents with matching state are merged together into a single extent in the
+ * tree.  Extents with EXTENT_IO in their state field are not merged because
+ * the end_io handlers need to be able to do operations on them without
+ * sleeping (or doing allocations/splits).
+ *
+ * This should be called with the tree lock held.
+ */
+void merge_state(struct extent_io_tree *tree, struct extent_state *state)
+{
+	struct extent_state *other;
+	struct rb_node *other_node;
+
+	if (state->state & (EXTENT_LOCKED | EXTENT_BOUNDARY))
+		return;
+
+	other_node = rb_prev(&state->rb_node);
+	if (other_node) {
+		other = rb_entry(other_node, struct extent_state, rb_node);
+		if (other->end == state->start - 1 &&
+		    other->state == state->state) {
+			if (tree->private_data &&
+			    is_data_inode(tree->private_data))
+				btrfs_merge_delalloc_extent(tree->private_data,
+							    state, other);
+			state->start = other->start;
+			rb_erase(&other->rb_node, &tree->state);
+			RB_CLEAR_NODE(&other->rb_node);
+			free_extent_state(other);
+		}
+	}
+	other_node = rb_next(&state->rb_node);
+	if (other_node) {
+		other = rb_entry(other_node, struct extent_state, rb_node);
+		if (other->start == state->end + 1 &&
+		    other->state == state->state) {
+			if (tree->private_data &&
+			    is_data_inode(tree->private_data))
+				btrfs_merge_delalloc_extent(tree->private_data,
+							    state, other);
+			state->end = other->end;
+			rb_erase(&other->rb_node, &tree->state);
+			RB_CLEAR_NODE(&other->rb_node);
+			free_extent_state(other);
+		}
+	}
+}
+
+void set_state_bits(struct extent_io_tree *tree, struct extent_state *state,
+		    u32 bits, struct extent_changeset *changeset)
+{
+	u32 bits_to_set = bits & ~EXTENT_CTLBITS;
+	int ret;
+
+	if (tree->private_data && is_data_inode(tree->private_data))
+		btrfs_set_delalloc_extent(tree->private_data, state, bits);
+
+	if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
+		u64 range = state->end - state->start + 1;
+		tree->dirty_bytes += range;
+	}
+	ret = add_extent_changeset(state, bits_to_set, changeset, 1);
+	BUG_ON(ret < 0);
+	state->state |= bits_to_set;
+}
+
+/*
+ * Insert an extent_state struct into the tree.  'bits' are set on the
+ * struct before it is inserted.
+ *
+ * This may return -EEXIST if the extent is already there, in which case the
+ * state struct is freed.
+ *
+ * The tree lock is not taken internally.  This is a utility function and
+ * probably isn't what you want to call (see set/clear_extent_bit).
+ */
+int insert_state(struct extent_io_tree *tree, struct extent_state *state,
+		 u32 bits, struct extent_changeset *changeset)
+{
+	struct rb_node **node;
+	struct rb_node *parent;
+	const u64 end = state->end;
+
+	set_state_bits(tree, state, bits, changeset);
+
+	node = &tree->state.rb_node;
+	while (*node) {
+		struct tree_entry *entry;
+
+		parent = *node;
+		entry = rb_entry(parent, struct tree_entry, rb_node);
+
+		if (end < entry->start) {
+			node = &(*node)->rb_left;
+		} else if (end > entry->end) {
+			node = &(*node)->rb_right;
+		} else {
+			btrfs_err(tree->fs_info,
+			       "found node %llu %llu on insert of %llu %llu",
+			       entry->start, entry->end, state->start, end);
+			return -EEXIST;
+		}
+	}
+
+	rb_link_node(&state->rb_node, parent, node);
+	rb_insert_color(&state->rb_node, &tree->state);
+
+	merge_state(tree, state);
+	return 0;
+}
+
+/*
+ * Insert state to @tree to the location given by @node and @parent.
+ */
+void insert_state_fast(struct extent_io_tree *tree, struct extent_state *state,
+		       struct rb_node **node, struct rb_node *parent,
+		       unsigned bits, struct extent_changeset *changeset)
+{
+	set_state_bits(tree, state, bits, changeset);
+	rb_link_node(&state->rb_node, parent, node);
+	rb_insert_color(&state->rb_node, &tree->state);
+	merge_state(tree, state);
+}
+
+/*
+ * Split a given extent state struct in two, inserting the preallocated
+ * struct 'prealloc' as the newly created second half.  'split' indicates an
+ * offset inside 'orig' where it should be split.
+ *
+ * Before calling,
+ * the tree has 'orig' at [orig->start, orig->end].  After calling, there
+ * are two extent state structs in the tree:
+ * prealloc: [orig->start, split - 1]
+ * orig: [ split, orig->end ]
+ *
+ * The tree locks are not taken by this function. They need to be held
+ * by the caller.
+ */
+int split_state(struct extent_io_tree *tree, struct extent_state *orig,
+		struct extent_state *prealloc, u64 split)
+{
+	struct rb_node *parent = NULL;
+	struct rb_node **node;
+
+	if (tree->private_data && is_data_inode(tree->private_data))
+		btrfs_split_delalloc_extent(tree->private_data, orig, split);
+
+	prealloc->start = orig->start;
+	prealloc->end = split - 1;
+	prealloc->state = orig->state;
+	orig->start = split;
+
+	parent = &orig->rb_node;
+	node = &parent;
+	while (*node) {
+		struct tree_entry *entry;
+
+		parent = *node;
+		entry = rb_entry(parent, struct tree_entry, rb_node);
+
+		if (prealloc->end < entry->start) {
+			node = &(*node)->rb_left;
+		} else if (prealloc->end > entry->end) {
+			node = &(*node)->rb_right;
+		} else {
+			free_extent_state(prealloc);
+			return -EEXIST;
+		}
+	}
+
+	rb_link_node(&prealloc->rb_node, parent, node);
+	rb_insert_color(&prealloc->rb_node, &tree->state);
+
+	return 0;
+}
+
+/*
+ * Utility function to clear some bits in an extent state struct.  It will
+ * optionally wake up anyone waiting on this state (wake == 1).
+ *
+ * If no bits are set on the state struct after clearing things, the
+ * struct is freed and removed from the tree
+ */
+struct extent_state *clear_state_bit(struct extent_io_tree *tree,
+				     struct extent_state *state, u32 bits,
+				     int wake,
+				     struct extent_changeset *changeset)
+{
+	struct extent_state *next;
+	u32 bits_to_clear = bits & ~EXTENT_CTLBITS;
+	int ret;
+
+	if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
+		u64 range = state->end - state->start + 1;
+		WARN_ON(range > tree->dirty_bytes);
+		tree->dirty_bytes -= range;
+	}
+
+	if (tree->private_data && is_data_inode(tree->private_data))
+		btrfs_clear_delalloc_extent(tree->private_data, state, bits);
+
+	ret = add_extent_changeset(state, bits_to_clear, changeset, 0);
+	BUG_ON(ret < 0);
+	state->state &= ~bits_to_clear;
+	if (wake)
+		wake_up(&state->wq);
+	if (state->state == 0) {
+		next = next_state(state);
+		if (extent_state_in_tree(state)) {
+			rb_erase(&state->rb_node, &tree->state);
+			RB_CLEAR_NODE(&state->rb_node);
+			free_extent_state(state);
+		} else {
+			WARN_ON(1);
+		}
+	} else {
+		merge_state(tree, state);
+		next = next_state(state);
+	}
+	return next;
+}
+
 /* Wrappers around set/clear extent bit */
 int set_record_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
 			   u32 bits, struct extent_changeset *changeset)
diff --git a/fs/btrfs/extent-io-tree.h b/fs/btrfs/extent-io-tree.h
index ce07432954b4..92cbb1dc5ce2 100644
--- a/fs/btrfs/extent-io-tree.h
+++ b/fs/btrfs/extent-io-tree.h
@@ -291,5 +291,31 @@ struct rb_node *tree_search_for_insert(struct extent_io_tree *tree, u64 offset,
 struct rb_node *tree_search_prev_next(struct extent_io_tree *tree, u64 offset,
 				      struct rb_node **prev_ret,
 				      struct rb_node **next_ret);
+void merge_state(struct extent_io_tree *tree, struct extent_state *state);
+
+static inline struct extent_state *next_state(struct extent_state *state)
+{
+	struct rb_node *next = rb_next(&state->rb_node);
+	if (next)
+		return rb_entry(next, struct extent_state, rb_node);
+	else
+		return NULL;
+}
+
+struct extent_state *clear_state_bit(struct extent_io_tree *tree,
+				     struct extent_state *state, u32 bits,
+				     int wake,
+				     struct extent_changeset *changeset);
+int insert_state(struct extent_io_tree *tree, struct extent_state *state,
+		 u32 bits, struct extent_changeset *changeset);
+int split_state(struct extent_io_tree *tree, struct extent_state *orig,
+		struct extent_state *prealloc, u64 split);
+int insert_state(struct extent_io_tree *tree, struct extent_state *state,
+		 u32 bits, struct extent_changeset *changeset);
+void insert_state_fast(struct extent_io_tree *tree, struct extent_state *state,
+		       struct rb_node **node, struct rb_node *parent,
+		       unsigned bits, struct extent_changeset *changeset);
+void set_state_bits(struct extent_io_tree *tree, struct extent_state *state,
+		    u32 bits, struct extent_changeset *changeset);
 
 #endif /* BTRFS_EXTENT_IO_TREE_H */
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index e3fb38752469..c488be817106 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -108,24 +108,6 @@ struct extent_page_data {
 	unsigned int sync_io:1;
 };
 
-static int add_extent_changeset(struct extent_state *state, u32 bits,
-				 struct extent_changeset *changeset,
-				 int set)
-{
-	int ret;
-
-	if (!changeset)
-		return 0;
-	if (set && (state->state & bits) == bits)
-		return 0;
-	if (!set && (state->state & bits) == 0)
-		return 0;
-	changeset->bytes_changed += state->end - state->start + 1;
-	ret = ulist_add(&changeset->range_changed, state->start, state->end,
-			GFP_ATOMIC);
-	return ret;
-}
-
 static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl)
 {
 	struct bio *bio;
@@ -207,227 +189,6 @@ static inline struct rb_node *tree_search(struct extent_io_tree *tree, u64 offse
 	return tree_search_for_insert(tree, offset, NULL, NULL);
 }
 
-/*
- * utility function to look for merge candidates inside a given range.
- * Any extents with matching state are merged together into a single
- * extent in the tree.  Extents with EXTENT_IO in their state field
- * are not merged because the end_io handlers need to be able to do
- * operations on them without sleeping (or doing allocations/splits).
- *
- * This should be called with the tree lock held.
- */
-static void merge_state(struct extent_io_tree *tree,
-		        struct extent_state *state)
-{
-	struct extent_state *other;
-	struct rb_node *other_node;
-
-	if (state->state & (EXTENT_LOCKED | EXTENT_BOUNDARY))
-		return;
-
-	other_node = rb_prev(&state->rb_node);
-	if (other_node) {
-		other = rb_entry(other_node, struct extent_state, rb_node);
-		if (other->end == state->start - 1 &&
-		    other->state == state->state) {
-			if (tree->private_data &&
-			    is_data_inode(tree->private_data))
-				btrfs_merge_delalloc_extent(tree->private_data,
-							    state, other);
-			state->start = other->start;
-			rb_erase(&other->rb_node, &tree->state);
-			RB_CLEAR_NODE(&other->rb_node);
-			free_extent_state(other);
-		}
-	}
-	other_node = rb_next(&state->rb_node);
-	if (other_node) {
-		other = rb_entry(other_node, struct extent_state, rb_node);
-		if (other->start == state->end + 1 &&
-		    other->state == state->state) {
-			if (tree->private_data &&
-			    is_data_inode(tree->private_data))
-				btrfs_merge_delalloc_extent(tree->private_data,
-							    state, other);
-			state->end = other->end;
-			rb_erase(&other->rb_node, &tree->state);
-			RB_CLEAR_NODE(&other->rb_node);
-			free_extent_state(other);
-		}
-	}
-}
-
-static void set_state_bits(struct extent_io_tree *tree,
-			   struct extent_state *state, u32 bits,
-			   struct extent_changeset *changeset);
-
-/*
- * insert an extent_state struct into the tree.  'bits' are set on the
- * struct before it is inserted.
- *
- * This may return -EEXIST if the extent is already there, in which case the
- * state struct is freed.
- *
- * The tree lock is not taken internally.  This is a utility function and
- * probably isn't what you want to call (see set/clear_extent_bit).
- */
-static int insert_state(struct extent_io_tree *tree,
-			struct extent_state *state,
-			u32 bits, struct extent_changeset *changeset)
-{
-	struct rb_node **node;
-	struct rb_node *parent;
-	const u64 end = state->end;
-
-	set_state_bits(tree, state, bits, changeset);
-
-	node = &tree->state.rb_node;
-	while (*node) {
-		struct tree_entry *entry;
-
-		parent = *node;
-		entry = rb_entry(parent, struct tree_entry, rb_node);
-
-		if (end < entry->start) {
-			node = &(*node)->rb_left;
-		} else if (end > entry->end) {
-			node = &(*node)->rb_right;
-		} else {
-			btrfs_err(tree->fs_info,
-			       "found node %llu %llu on insert of %llu %llu",
-			       entry->start, entry->end, state->start, end);
-			return -EEXIST;
-		}
-	}
-
-	rb_link_node(&state->rb_node, parent, node);
-	rb_insert_color(&state->rb_node, &tree->state);
-
-	merge_state(tree, state);
-	return 0;
-}
-
-/*
- * Insert state to @tree to the location given by @node and @parent.
- */
-static void insert_state_fast(struct extent_io_tree *tree,
-			      struct extent_state *state, struct rb_node **node,
-			      struct rb_node *parent, unsigned bits,
-			      struct extent_changeset *changeset)
-{
-	set_state_bits(tree, state, bits, changeset);
-	rb_link_node(&state->rb_node, parent, node);
-	rb_insert_color(&state->rb_node, &tree->state);
-	merge_state(tree, state);
-}
-
-/*
- * split a given extent state struct in two, inserting the preallocated
- * struct 'prealloc' as the newly created second half.  'split' indicates an
- * offset inside 'orig' where it should be split.
- *
- * Before calling,
- * the tree has 'orig' at [orig->start, orig->end].  After calling, there
- * are two extent state structs in the tree:
- * prealloc: [orig->start, split - 1]
- * orig: [ split, orig->end ]
- *
- * The tree locks are not taken by this function. They need to be held
- * by the caller.
- */
-static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
-		       struct extent_state *prealloc, u64 split)
-{
-	struct rb_node *parent = NULL;
-	struct rb_node **node;
-
-	if (tree->private_data && is_data_inode(tree->private_data))
-		btrfs_split_delalloc_extent(tree->private_data, orig, split);
-
-	prealloc->start = orig->start;
-	prealloc->end = split - 1;
-	prealloc->state = orig->state;
-	orig->start = split;
-
-	parent = &orig->rb_node;
-	node = &parent;
-	while (*node) {
-		struct tree_entry *entry;
-
-		parent = *node;
-		entry = rb_entry(parent, struct tree_entry, rb_node);
-
-		if (prealloc->end < entry->start) {
-			node = &(*node)->rb_left;
-		} else if (prealloc->end > entry->end) {
-			node = &(*node)->rb_right;
-		} else {
-			free_extent_state(prealloc);
-			return -EEXIST;
-		}
-	}
-
-	rb_link_node(&prealloc->rb_node, parent, node);
-	rb_insert_color(&prealloc->rb_node, &tree->state);
-
-	return 0;
-}
-
-static struct extent_state *next_state(struct extent_state *state)
-{
-	struct rb_node *next = rb_next(&state->rb_node);
-	if (next)
-		return rb_entry(next, struct extent_state, rb_node);
-	else
-		return NULL;
-}
-
-/*
- * utility function to clear some bits in an extent state struct.
- * it will optionally wake up anyone waiting on this state (wake == 1).
- *
- * If no bits are set on the state struct after clearing things, the
- * struct is freed and removed from the tree
- */
-static struct extent_state *clear_state_bit(struct extent_io_tree *tree,
-					    struct extent_state *state,
-					    u32 bits, int wake,
-					    struct extent_changeset *changeset)
-{
-	struct extent_state *next;
-	u32 bits_to_clear = bits & ~EXTENT_CTLBITS;
-	int ret;
-
-	if ((bits_to_clear & EXTENT_DIRTY) && (state->state & EXTENT_DIRTY)) {
-		u64 range = state->end - state->start + 1;
-		WARN_ON(range > tree->dirty_bytes);
-		tree->dirty_bytes -= range;
-	}
-
-	if (tree->private_data && is_data_inode(tree->private_data))
-		btrfs_clear_delalloc_extent(tree->private_data, state, bits);
-
-	ret = add_extent_changeset(state, bits_to_clear, changeset, 0);
-	BUG_ON(ret < 0);
-	state->state &= ~bits_to_clear;
-	if (wake)
-		wake_up(&state->wq);
-	if (state->state == 0) {
-		next = next_state(state);
-		if (extent_state_in_tree(state)) {
-			rb_erase(&state->rb_node, &tree->state);
-			RB_CLEAR_NODE(&state->rb_node);
-			free_extent_state(state);
-		} else {
-			WARN_ON(1);
-		}
-	} else {
-		merge_state(tree, state);
-		next = next_state(state);
-	}
-	return next;
-}
-
 static void extent_io_tree_panic(struct extent_io_tree *tree, int err)
 {
 	btrfs_panic(tree->fs_info, err,
@@ -663,25 +424,6 @@ out:
 	spin_unlock(&tree->lock);
 }
 
-static void set_state_bits(struct extent_io_tree *tree,
-			   struct extent_state *state,
-			   u32 bits, struct extent_changeset *changeset)
-{
-	u32 bits_to_set = bits & ~EXTENT_CTLBITS;
-	int ret;
-
-	if (tree->private_data && is_data_inode(tree->private_data))
-		btrfs_set_delalloc_extent(tree->private_data, state, bits);
-
-	if ((bits_to_set & EXTENT_DIRTY) && !(state->state & EXTENT_DIRTY)) {
-		u64 range = state->end - state->start + 1;
-		tree->dirty_bytes += range;
-	}
-	ret = add_extent_changeset(state, bits_to_set, changeset, 1);
-	BUG_ON(ret < 0);
-	state->state |= bits_to_set;
-}
-
 static void cache_state_if_flags(struct extent_state *state,
 				 struct extent_state **cached_ptr,
 				 unsigned flags)