Btrfs: directory inode index is back

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/TODO

 * cleanup, add more error checking, get rid of BUG_ONs
 * Fix ENOSPC handling
-* Add block mapping tree (simple dm layer)
 * Make allocator smarter
 * add a block group to struct inode
-* Make sure nobh stuff is working properly for cows
 * Do actual block accounting
 * Check compat and incompat flags on the inode
 * Get rid of struct ctree_path, limiting tree levels held at one time
+* Add generation number to key pointer in nodes
+* Add parent pointer back to extent map.
 * Release
 * Do real tree locking
 * Add extent mirroring (backup copies of blocks)

fs/btrfs/ctree.h

@@ -185,11 +185,6 @@ struct btrfs_inode_item {
 	struct btrfs_inode_timespec otime;
 } __attribute__ ((__packed__));
 
-/* inline data is just a blob of bytes */
-struct btrfs_inline_data_item {
-	u8 data;
-} __attribute__ ((__packed__));
-
 struct btrfs_dir_item {
 	struct btrfs_disk_key location;
 	__le16 flags;
@@ -293,9 +288,6 @@ struct btrfs_root {
 #define BTRFS_KEY_TYPE_MASK	(((u32)BTRFS_KEY_TYPE_MAX - 1) << \
 				  BTRFS_KEY_TYPE_SHIFT)
 
-#define BTRFS_KEY_OVERFLOW_MAX 128
-#define BTRFS_KEY_OVERFLOW_MASK ((u32)BTRFS_KEY_OVERFLOW_MAX - 1)
-
 /*
  * inode items have the data typically returned from stat and store other
  * info about object characteristics.  There is one for every file and dir in
@@ -621,31 +613,6 @@ static inline void btrfs_set_key_type(struct btrfs_key *key, u32 val)
 	key->flags = (key->flags & ~(BTRFS_KEY_TYPE_MASK)) | val;
 }
 
-static inline u32 btrfs_key_overflow(struct btrfs_key *key)
-{
-	return key->flags & BTRFS_KEY_OVERFLOW_MASK;
-}
-
-static inline void btrfs_set_key_overflow(struct btrfs_key *key, u32 over)
-{
-	BUG_ON(over >= BTRFS_KEY_OVERFLOW_MAX);
-	key->flags = (key->flags & ~BTRFS_KEY_OVERFLOW_MASK) | over;
-}
-
-static inline u32 btrfs_disk_key_overflow(struct btrfs_disk_key *key)
-{
-	return le32_to_cpu(key->flags) & BTRFS_KEY_OVERFLOW_MASK;
-}
-
-static inline void btrfs_set_disk_key_overflow(struct btrfs_disk_key *key,
-					       u32 over)
-{
-	u32 flags = btrfs_disk_key_flags(key);
-	BUG_ON(over >= BTRFS_KEY_OVERFLOW_MAX);
-	flags = (flags & ~BTRFS_KEY_OVERFLOW_MASK) | over;
-	btrfs_set_disk_key_flags(key, flags);
-}
-
 static inline u64 btrfs_header_blocknr(struct btrfs_header *h)
 {
 	return le64_to_cpu(h->blocknr);
@@ -1079,15 +1046,24 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 			  *root, const char *name, int name_len, u64 dir,
 			  struct btrfs_key *location, u8 type);
-int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
-			  *root, struct btrfs_path *path, u64 dir,
-			  const char *name, int name_len, int mod);
-int btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
-				struct btrfs_root *root,
-				struct btrfs_path *path, u64 dir,
-				u64 objectid, int mod);
-int btrfs_match_dir_item_name(struct btrfs_root *root, struct btrfs_path *path,
+struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
+					     struct btrfs_root *root,
+					     struct btrfs_path *path, u64 dir,
+					     const char *name, int name_len,
+					     int mod);
+struct btrfs_dir_item *
+btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root,
+			    struct btrfs_path *path, u64 dir,
+			    u64 objectid, const char *name, int name_len,
+			    int mod);
+struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
+			      struct btrfs_path *path,
 			      const char *name, int name_len);
+int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root,
+			      struct btrfs_path *path,
+			      struct btrfs_dir_item *di);
 /* inode-map.c */
 int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *fs_root,

fs/btrfs/dir-item.c

@@ -4,24 +4,31 @@
 #include "hash.h"
 #include "transaction.h"
 
-int insert_with_overflow(struct btrfs_trans_handle *trans, struct btrfs_root
-			    *root, struct btrfs_path *path, struct btrfs_key
-			    *cpu_key, u32 data_size)
+struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle *trans,
+					    struct btrfs_root *root,
+					    struct btrfs_path *path,
+					    struct btrfs_key *cpu_key,
+					    u32 data_size)
 {
-	int overflow;
 	int ret;
+	char *ptr;
+	struct btrfs_item *item;
+	struct btrfs_leaf *leaf;
 
 	ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
-	overflow = btrfs_key_overflow(cpu_key);
-
-	while(ret == -EEXIST && overflow < BTRFS_KEY_OVERFLOW_MAX) {
-		overflow++;
-		btrfs_set_key_overflow(cpu_key, overflow);
-		btrfs_release_path(root, path);
-		ret = btrfs_insert_empty_item(trans, root, path, cpu_key,
-					      data_size);
+	if (ret == -EEXIST) {
+		ret = btrfs_extend_item(trans, root, path, data_size);
+		WARN_ON(ret > 0);
+		if (ret)
+			return ERR_PTR(ret);
 	}
-	return ret;
+	WARN_ON(ret > 0);
+	leaf = btrfs_buffer_leaf(path->nodes[0]);
+	item = leaf->items + path->slots[0];
+	ptr = btrfs_item_ptr(leaf, path->slots[0], char);
+	BUG_ON(data_size > btrfs_item_size(item));
+	ptr += btrfs_item_size(item) - data_size;
+	return (struct btrfs_dir_item *)ptr;
 }
 
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
@@ -43,13 +50,12 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	path = btrfs_alloc_path();
 	btrfs_init_path(path);
 	data_size = sizeof(*dir_item) + name_len;
-	ret = insert_with_overflow(trans, root, path, &key, data_size);
-	if (ret)
+	dir_item = insert_with_overflow(trans, root, path, &key, data_size);
+	if (IS_ERR(dir_item)) {
+		ret = PTR_ERR(dir_item);
 		goto out;
+	}
 
-	dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
-				  path->slots[0],
-				  struct btrfs_dir_item);
 	btrfs_cpu_key_to_disk(&dir_item->location, location);
 	btrfs_set_dir_type(dir_item, type);
 	btrfs_set_dir_flags(dir_item, 0);
@@ -58,15 +64,39 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 
 	btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
 	btrfs_mark_buffer_dirty(path->nodes[0]);
-out:
+
+	/* FIXME, use some real flag for selecting the extra index */
+	if (root == root->fs_info->tree_root) {
+		ret = 0;
+		goto out;
+	}
+
 	btrfs_release_path(root, path);
+
+	btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
+	key.offset = location->objectid;
+	dir_item = insert_with_overflow(trans, root, path, &key, data_size);
+	if (IS_ERR(dir_item)) {
+		ret = PTR_ERR(dir_item);
+		goto out;
+	}
+	btrfs_cpu_key_to_disk(&dir_item->location, location);
+	btrfs_set_dir_type(dir_item, type);
+	btrfs_set_dir_flags(dir_item, 0);
+	btrfs_set_dir_name_len(dir_item, name_len);
+	name_ptr = (char *)(dir_item + 1);
+	btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
+	btrfs_mark_buffer_dirty(path->nodes[0]);
+out:
 	btrfs_free_path(path);
 	return ret;
 }
 
-int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
-			  *root, struct btrfs_path *path, u64 dir,
-			  const char *name, int name_len, int mod)
+struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
+					     struct btrfs_root *root,
+					     struct btrfs_path *path, u64 dir,
+					     const char *name, int name_len,
+					     int mod)
 {
 	int ret;
 	struct btrfs_key key;
@@ -74,57 +104,111 @@ int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 	int cow = mod != 0;
 	struct btrfs_disk_key *found_key;
 	struct btrfs_leaf *leaf;
-	u32 overflow;
 
 	key.objectid = dir;
 	key.flags = 0;
 	btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
-	// btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
 	ret = btrfs_name_hash(name, name_len, &key.offset);
 	BUG_ON(ret);
-	while(1) {
-		ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
-		if (ret < 0)
-			return ret;
-		if (ret > 0) {
-			if (path->slots[0] == 0)
-				return 1;
-			path->slots[0]--;
-		}
-		leaf = btrfs_buffer_leaf(path->nodes[0]);
-		found_key = &leaf->items[path->slots[0]].key;
-
-		if (btrfs_disk_key_objectid(found_key) != dir ||
-		    btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
-		    btrfs_disk_key_offset(found_key) != key.offset)
-			return 1;
-
-		if (btrfs_match_dir_item_name(root, path, name, name_len))
-			return 0;
-
-		overflow = btrfs_disk_key_overflow(found_key);
-		if (overflow == 0)
-			return 1;
-		btrfs_set_key_overflow(&key, overflow - 1);
-		btrfs_release_path(root, path);
+	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+	if (ret < 0)
+		return ERR_PTR(ret);
+	if (ret > 0) {
+		if (path->slots[0] == 0)
+			return NULL;
+		path->slots[0]--;
 	}
-	return 1;
+	leaf = btrfs_buffer_leaf(path->nodes[0]);
+	found_key = &leaf->items[path->slots[0]].key;
+
+	if (btrfs_disk_key_objectid(found_key) != dir ||
+	    btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
+	    btrfs_disk_key_offset(found_key) != key.offset)
+		return NULL;
+
+	return btrfs_match_dir_item_name(root, path, name, name_len);
 }
 
-int btrfs_match_dir_item_name(struct btrfs_root *root,
+struct btrfs_dir_item *
+btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
+			    struct btrfs_root *root,
+			    struct btrfs_path *path, u64 dir,
+			    u64 objectid, const char *name, int name_len,
+			    int mod)
+{
+	int ret;
+	struct btrfs_key key;
+	int ins_len = mod < 0 ? -1 : 0;
+	int cow = mod != 0;
+
+	key.objectid = dir;
+	key.flags = 0;
+	btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
+	key.offset = objectid;
+
+	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+	if (ret < 0)
+		return ERR_PTR(ret);
+	if (ret > 0)
+		return ERR_PTR(-ENOENT);
+	return btrfs_match_dir_item_name(root, path, name, name_len);
+}
+
+struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
 			      struct btrfs_path *path,
 			      const char *name, int name_len)
 {
 	struct btrfs_dir_item *dir_item;
 	char *name_ptr;
+	u32 total_len;
+	u32 cur = 0;
+	u32 this_len;
+	struct btrfs_leaf *leaf;
 
-	dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
-				  path->slots[0],
-				  struct btrfs_dir_item);
-	if (btrfs_dir_name_len(dir_item) != name_len)
-		return 0;
-	name_ptr = (char *)(dir_item + 1);
-	if (memcmp(name_ptr, name, name_len))
-		return 0;
-	return 1;
+	leaf = btrfs_buffer_leaf(path->nodes[0]);
+	dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
+	total_len = btrfs_item_size(leaf->items + path->slots[0]);
+	while(cur < total_len) {
+		this_len = sizeof(*dir_item) + btrfs_dir_name_len(dir_item);
+		name_ptr = (char *)(dir_item + 1);
+
+		if (btrfs_dir_name_len(dir_item) == name_len &&
+		    memcmp(name_ptr, name, name_len) == 0)
+			return dir_item;
+
+		cur += this_len;
+		dir_item = (struct btrfs_dir_item *)((char *)dir_item +
+						     this_len);
+	}
+	return NULL;
 }
+
+int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root,
+			      struct btrfs_path *path,
+			      struct btrfs_dir_item *di)
+{
+
+	struct btrfs_leaf *leaf;
+	u32 sub_item_len;
+	u32 item_len;
+	int ret;
+
+	leaf = btrfs_buffer_leaf(path->nodes[0]);
+	sub_item_len = sizeof(*di) + btrfs_dir_name_len(di);
+	item_len = btrfs_item_size(leaf->items + path->slots[0]);
+	if (sub_item_len == btrfs_item_size(leaf->items + path->slots[0])) {
+		ret = btrfs_del_item(trans, root, path);
+		BUG_ON(ret);
+	} else {
+		char *ptr = (char *)di;
+		char *start = btrfs_item_ptr(leaf, path->slots[0], char);
+		btrfs_memmove(root, leaf, ptr, ptr + sub_item_len,
+			item_len - (ptr + sub_item_len - start));
+		ret = btrfs_truncate_item(trans, root, path,
+					  item_len - sub_item_len);
+		BUG_ON(ret);
+	}
+	return 0;
+}
+