Btrfs-progs: pull back backref.c and fix it up

This patch pulls back backref.c, adds a couple of helpers everywhere that it
needs, and cleans up backref.c to fit in btrfs-progs.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
[removed free_some_buffers after "do not reclaim extent buffer"]
Signed-off-by: David Sterba <dsterba@suse.cz>

Makefile

@@ -10,7 +10,7 @@ objects = ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
 	  root-tree.o dir-item.o file-item.o inode-item.o inode-map.o \
 	  extent-cache.o extent_io.o volumes.o utils.o repair.o \
 	  qgroup.o raid6.o free-space-cache.o list_sort.o props.o \
-	  ulist.o qgroup-verify.o
+	  ulist.o qgroup-verify.o backref.o
 cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \
 	       cmds-inspect.o cmds-balance.o cmds-send.o cmds-receive.o \
 	       cmds-quota.o cmds-qgroup.o cmds-replace.o cmds-check.o \

backref.h

@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2011 STRATO.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_BACKREF__
+#define __BTRFS_BACKREF__
+
+#include "ulist.h"
+#include "extent_io.h"
+
+struct inode_fs_paths {
+	struct btrfs_path		*btrfs_path;
+	struct btrfs_root		*fs_root;
+	struct btrfs_data_container	*fspath;
+};
+
+typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root,
+		void *ctx);
+
+int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root,
+			struct btrfs_path *path);
+
+int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
+			struct btrfs_path *path, struct btrfs_key *found_key,
+			u64 *flags);
+
+int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
+			    struct btrfs_key *key, struct btrfs_extent_item *ei,
+			    u32 item_size, u64 *out_root, u8 *out_level);
+
+int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
+				u64 extent_item_objectid,
+				u64 extent_offset, int search_commit_root,
+				iterate_extent_inodes_t *iterate, void *ctx);
+
+int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
+				struct btrfs_path *path,
+				iterate_extent_inodes_t *iterate, void *ctx);
+
+int paths_from_inode(u64 inum, struct inode_fs_paths *ipath);
+
+int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
+			 struct btrfs_fs_info *fs_info, u64 bytenr,
+			 u64 time_seq, struct ulist **roots);
+char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
+			u32 name_len, unsigned long name_off,
+			struct extent_buffer *eb_in, u64 parent,
+			char *dest, u32 size);
+
+struct btrfs_data_container *init_data_container(u32 total_bytes);
+struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
+					struct btrfs_path *path);
+void free_ipath(struct inode_fs_paths *ipath);
+
+int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
+			  u64 start_off, struct btrfs_path *path,
+			  struct btrfs_inode_extref **ret_extref,
+			  u64 *found_off);
+#endif

ctree.c

@@ -1021,6 +1021,49 @@ void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
 	}
 }
 
+int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path,
+		u64 iobjectid, u64 ioff, u8 key_type,
+		struct btrfs_key *found_key)
+{
+	int ret;
+	struct btrfs_key key;
+	struct extent_buffer *eb;
+	struct btrfs_path *path;
+
+	key.type = key_type;
+	key.objectid = iobjectid;
+	key.offset = ioff;
+
+	if (found_path == NULL) {
+		path = btrfs_alloc_path();
+		if (!path)
+			return -ENOMEM;
+	} else
+		path = found_path;
+
+	ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0);
+	if ((ret < 0) || (found_key == NULL)) {
+		if (path != found_path)
+			btrfs_free_path(path);
+		return ret;
+	}
+
+	eb = path->nodes[0];
+	if (ret && path->slots[0] >= btrfs_header_nritems(eb)) {
+		ret = btrfs_next_leaf(fs_root, path);
+		if (ret)
+			return ret;
+		eb = path->nodes[0];
+	}
+
+	btrfs_item_key_to_cpu(eb, found_key, path->slots[0]);
+	if (found_key->type != key.type ||
+			found_key->objectid != key.objectid)
+		return 1;
+
+	return 0;
+}
+
 /*
  * look for key in the tree.  path is filled in with nodes along the way
  * if key is found, we return zero and you can find the item in the leaf
@@ -2813,3 +2856,44 @@ int btrfs_previous_item(struct btrfs_root *root,
 	return 1;
 }
 
+/*
+ * search in extent tree to find a previous Metadata/Data extent item with
+ * min objecitd.
+ *
+ * returns 0 if something is found, 1 if nothing was found and < 0 on error
+ */
+int btrfs_previous_extent_item(struct btrfs_root *root,
+			struct btrfs_path *path, u64 min_objectid)
+{
+	struct btrfs_key found_key;
+	struct extent_buffer *leaf;
+	u32 nritems;
+	int ret;
+
+	while (1) {
+		if (path->slots[0] == 0) {
+			ret = btrfs_prev_leaf(root, path);
+			if (ret != 0)
+				return ret;
+		} else {
+			path->slots[0]--;
+		}
+		leaf = path->nodes[0];
+		nritems = btrfs_header_nritems(leaf);
+		if (nritems == 0)
+			return 1;
+		if (path->slots[0] == nritems)
+			path->slots[0]--;
+
+		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+		if (found_key.objectid < min_objectid)
+			break;
+		if (found_key.type == BTRFS_EXTENT_ITEM_KEY ||
+		    found_key.type == BTRFS_METADATA_ITEM_KEY)
+			return 0;
+		if (found_key.objectid == min_objectid &&
+		    found_key.type < BTRFS_EXTENT_ITEM_KEY)
+			break;
+	}
+	return 1;
+}

ctree.h

@@ -2253,6 +2253,8 @@ struct extent_buffer *read_node_slot(struct btrfs_root *root,
 int btrfs_previous_item(struct btrfs_root *root,
 			struct btrfs_path *path, u64 min_objectid,
 			int type);
+int btrfs_previous_extent_item(struct btrfs_root *root,
+			struct btrfs_path *path, u64 min_objectid);
 int btrfs_cow_block(struct btrfs_trans_handle *trans,
 		    struct btrfs_root *root, struct extent_buffer *buf,
 		    struct extent_buffer *parent, int parent_slot,
@@ -2281,6 +2283,9 @@ int btrfs_split_item(struct btrfs_trans_handle *trans,
 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
 		      *root, struct btrfs_key *key, struct btrfs_path *p, int
 		      ins_len, int cow);
+int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *found_path,
+		u64 iobjectid, u64 ioff, u8 key_type,
+		struct btrfs_key *found_key);
 void btrfs_release_path(struct btrfs_path *p);
 void add_root_to_dirty_list(struct btrfs_root *root);
 struct btrfs_path *btrfs_alloc_path(void);
@@ -2313,6 +2318,15 @@ static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
 }
 
 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
+static inline int btrfs_next_item(struct btrfs_root *root,
+				  struct btrfs_path *p)
+{
+	++p->slots[0];
+	if (p->slots[0] >= btrfs_header_nritems(p->nodes[0]))
+		return btrfs_next_leaf(root, p);
+	return 0;
+}
+
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf);
 void btrfs_fixup_low_keys(struct btrfs_root *root, struct btrfs_path *path,

extent_io.c

@@ -539,7 +539,6 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
 						   u64 bytenr, u32 blocksize)
 {
 	struct extent_buffer *eb;
-	int ret;
 
 	eb = malloc(sizeof(struct extent_buffer) + blocksize);
 	if (!eb) {
@@ -559,16 +558,23 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree,
 	eb->cache_node.size = blocksize;
 	INIT_LIST_HEAD(&eb->recow);
 
-	ret = insert_cache_extent(&tree->cache, &eb->cache_node);
-	if (ret) {
-		free(eb);
-		return NULL;
-	}
-	list_add_tail(&eb->lru, &tree->lru);
-	tree->cache_size += blocksize;
 	return eb;
 }
 
+struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
+{
+	struct extent_buffer *new;
+
+	new = __alloc_extent_buffer(NULL, src->start, src->len);
+	if (new == NULL)
+		return NULL;
+
+	copy_extent_buffer(new, src, 0, 0, src->len);
+	new->flags |= EXTENT_BUFFER_DUMMY;
+
+	return new;
+}
+
 void free_extent_buffer(struct extent_buffer *eb)
 {
 	if (!eb)
@@ -581,9 +587,11 @@ void free_extent_buffer(struct extent_buffer *eb)
 		BUG_ON(eb->flags & EXTENT_DIRTY);
 		list_del_init(&eb->lru);
 		list_del_init(&eb->recow);
-		remove_cache_extent(&tree->cache, &eb->cache_node);
-		BUG_ON(tree->cache_size < eb->len);
-		tree->cache_size -= eb->len;
+		if (!(eb->flags & EXTENT_BUFFER_DUMMY)) {
+			BUG_ON(tree->cache_size < eb->len);
+			remove_cache_extent(&tree->cache, &eb->cache_node);
+			tree->cache_size -= eb->len;
+		}
 		free(eb);
 	}
 }
@@ -632,12 +640,23 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
 		list_move_tail(&eb->lru, &tree->lru);
 		eb->refs++;
 	} else {
+		int ret;
+
 		if (cache) {
 			eb = container_of(cache, struct extent_buffer,
 					  cache_node);
 			free_extent_buffer(eb);
 		}
 		eb = __alloc_extent_buffer(tree, bytenr, blocksize);
+		if (!eb)
+			return NULL;
+		ret = insert_cache_extent(&tree->cache, &eb->cache_node);
+		if (ret) {
+			free(eb);
+			return NULL;
+		}
+		list_add_tail(&eb->lru, &tree->lru);
+		tree->cache_size += blocksize;
 	}
 	return eb;
 }

extent_io.h

@@ -40,6 +40,7 @@
 #define EXTENT_BUFFER_FILLED (1 << 8)
 #define EXTENT_CSUM (1 << 9)
 #define EXTENT_BAD_TRANSID (1 << 10)
+#define EXTENT_BUFFER_DUMMY (1 << 11)
 #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
 
 #define BLOCK_GROUP_DATA     EXTENT_WRITEBACK
@@ -111,6 +112,7 @@ struct extent_buffer *find_first_extent_buffer(struct extent_io_tree *tree,
 					       u64 start);
 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
 					  u64 bytenr, u32 blocksize);
+struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
 void free_extent_buffer(struct extent_buffer *eb);
 int read_extent_from_disk(struct extent_buffer *eb,
 			  unsigned long offset, unsigned long len);

kerncompat.h

@@ -108,6 +108,9 @@ typedef __u32 u32;
 typedef __u64 u64;
 typedef __u16 u16;
 typedef __u8 u8;
+typedef __s64 s64;
+typedef __s32 s32;
+
 /*
  * Continuing to define __KERNEL__ breaks others parts of the code, so
  * we can just undefine it now that we have the correct headers...
@@ -119,6 +122,8 @@ typedef unsigned int __u32;
 typedef unsigned long long u64;
 typedef unsigned char u8;
 typedef unsigned short u16;
+typedef long long s64;
+typedef int s32
 #endif
 
 
@@ -269,6 +274,8 @@ static inline long IS_ERR(const void *ptr)
 #define kzalloc(x, y) calloc(1, x)
 #define kstrdup(x, y) strdup(x)
 #define kfree(x) free(x)
+#define vmalloc(x) malloc(x)
+#define vfree(x) free(x)
 
 #ifndef BTRFS_DISABLE_BACKTRACE
 #define BUG_ON(c) assert_trace(#c, __FILE__, __func__, __LINE__, !(c))

ulist.h

@@ -58,6 +58,21 @@ void ulist_free(struct ulist *ulist);
 int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask);
 int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
 		    u64 *old_aux, gfp_t gfp_mask);
+
+/* just like ulist_add_merge() but take a pointer for the aux data */
+static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux,
+				      void **old_aux, gfp_t gfp_mask)
+{
+#if BITS_PER_LONG == 32
+	u64 old64 = (uintptr_t)*old_aux;
+	int ret = ulist_add_merge(ulist, val, (uintptr_t)aux, &old64, gfp_mask);
+	*old_aux = (void *)((uintptr_t)old64);
+	return ret;
+#else
+	return ulist_add_merge(ulist, val, (u64)aux, (u64 *)old_aux, gfp_mask);
+#endif
+}
+
 struct ulist_node *ulist_next(struct ulist *ulist,
 			      struct ulist_iterator *uiter);