Btrfs: Pass down the expected generation number when reading tree blocks

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

Btrfs: Pass down the expected generation number when reading tree blocks
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Chris Mason
1 parent 188de649c5
Showing 6 changed files with 55 additions and 64 deletions Side-by-side Diff
fs/btrfs/ctree.c
fs/btrfs/disk-io.c
fs/btrfs/disk-io.h
fs/btrfs/extent-tree.c
fs/btrfs/print-tree.c
fs/btrfs/tree-defrag.c
@@ -302,6 +302,7 @@
 	struct extent_buffer *cur;
 	struct extent_buffer *tmp;
 	u64 blocknr;
+	u64 gen;
 	u64 search_start = *last_ret;
 	u64 last_block = 0;
 	u64 other;
@@ -354,6 +355,7 @@
  
 		progress_passed = 1;
 		blocknr = btrfs_node_blockptr(parent, i);
+		gen = btrfs_node_ptr_generation(parent, i);
 		if (last_block == 0)
 			last_block = blocknr;
  
  
  
@@ -387,15 +389,14 @@
 			}
 			if (!cur) {
 				cur = read_tree_block(root, blocknr,
-							 blocksize);
+							 blocksize, gen);
 			} else if (!uptodate) {
-				btrfs_read_buffer(cur);
+				btrfs_read_buffer(cur, gen);
 			}
 		}
 		if (search_start == 0)
 			search_start = last_block;
  
-		btrfs_verify_block_csum(root, cur);
 		err = __btrfs_cow_block(trans, root, cur, parent, i,
 					&tmp, search_start,
 					min(16 * blocksize,
  
  
@@ -696,12 +697,17 @@
 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
 				   struct extent_buffer *parent, int slot)
 {
+	int level = btrfs_header_level(parent);
 	if (slot < 0)
 		return NULL;
 	if (slot >= btrfs_header_nritems(parent))
 		return NULL;
+
+	BUG_ON(level == 0);
+
 	return read_tree_block(root, btrfs_node_blockptr(parent, slot),
-		       btrfs_level_size(root, btrfs_header_level(parent) - 1));
+		       btrfs_level_size(root, level - 1),
+		       btrfs_node_ptr_generation(parent, slot));
 }
  
 static int balance_level(struct btrfs_trans_handle *trans,
@@ -1076,7 +1082,8 @@
 		if ((search >= lowest_read && search <= highest_read) ||
 		    (search < lowest_read && lowest_read - search <= 32768) ||
 		    (search > highest_read && search - highest_read <= 32768)) {
-			readahead_tree_block(root, search, blocksize);
+			readahead_tree_block(root, search, blocksize,
+				     btrfs_node_ptr_generation(node, nr));
 			nread += blocksize;
 		}
 		nscan++;
@@ -1109,8 +1116,6 @@
 		      ins_len, int cow)
 {
 	struct extent_buffer *b;
-	u64 bytenr;
-	u64 ptr_gen;
 	int slot;
 	int ret;
 	int level;
  
@@ -1174,20 +1179,12 @@
 			/* this is only true while dropping a snapshot */
 			if (level == lowest_level)
 				break;
-			bytenr = btrfs_node_blockptr(b, slot);
-			ptr_gen = btrfs_node_ptr_generation(b, slot);
+
 			if (should_reada)
 				reada_for_search(root, p, level, slot,
 						 key->objectid);
-			b = read_tree_block(root, bytenr,
-					    btrfs_level_size(root, level - 1));
-			if (ptr_gen != btrfs_header_generation(b)) {
-				printk("block %llu bad gen wanted %llu "
-				       "found %llu\n",
-			        (unsigned long long)b->start,
-				(unsigned long long)ptr_gen,
-			        (unsigned long long)btrfs_header_generation(b));
-			}
+
+			b = read_node_slot(root, b, slot);
 		} else {
 			p->slots[level] = slot;
 			if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
@@ -1650,8 +1647,7 @@
 	if (slot >= btrfs_header_nritems(upper) - 1)
 		return 1;
  
-	right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
-				root->leafsize);
+	right = read_node_slot(root, upper, slot + 1);
 	free_space = btrfs_leaf_free_space(root, right);
 	if (free_space < data_size + sizeof(struct btrfs_item)) {
 		free_extent_buffer(right);
@@ -1826,8 +1822,7 @@
 		return 1;
 	}
  
-	left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
-			       slot - 1), root->leafsize);
+	left = read_node_slot(root, path->nodes[1], slot - 1);
 	free_space = btrfs_leaf_free_space(root, left);
 	if (free_space < data_size + sizeof(struct btrfs_item)) {
 		free_extent_buffer(left);
@@ -2742,7 +2737,6 @@
  */
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
 {
-	u64 bytenr;
 	int slot;
 	int level = 1;
 	struct extent_buffer *c;
  
@@ -2762,12 +2756,10 @@
 		}
 		slot--;
  
-		bytenr = btrfs_node_blockptr(c, slot);
 		if (next)
 			free_extent_buffer(next);
  
-		next = read_tree_block(root, bytenr,
-				       btrfs_level_size(root, level - 1));
+		next = read_node_slot(root, c, slot);
 		break;
 	}
 	path->slots[level] = slot;
@@ -2782,8 +2774,7 @@
 		path->slots[level] = slot;
 		if (!level)
 			break;
-		next = read_tree_block(root, btrfs_node_blockptr(next, slot),
-				       btrfs_level_size(root, level - 1));
+		next = read_node_slot(root, next, slot);
 	}
 	return 0;
 }
@@ -2797,7 +2788,6 @@
 {
 	int slot;
 	int level = 1;
-	u64 bytenr;
 	struct extent_buffer *c;
 	struct extent_buffer *next = NULL;
  
  
@@ -2814,15 +2804,13 @@
 			continue;
 		}
  
-		bytenr = btrfs_node_blockptr(c, slot);
 		if (next)
 			free_extent_buffer(next);
  
 		if (path->reada)
 			reada_for_search(root, path, level, slot, 0);
  
-		next = read_tree_block(root, bytenr,
-				       btrfs_level_size(root, level -1));
+		next = read_node_slot(root, c, slot);
 		break;
 	}
 	path->slots[level] = slot;
@@ -2836,8 +2824,7 @@
 			break;
 		if (path->reada)
 			reada_for_search(root, path, level, 0, 0);
-		next = read_tree_block(root, btrfs_node_blockptr(next, 0),
-				       btrfs_level_size(root, level - 1));
+		next = read_node_slot(root, next, 0);
 	}
 	return 0;
 }
@@ -207,7 +207,7 @@
  
 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
 					  struct extent_buffer *eb,
-					  u64 start)
+					  u64 start, u64 parent_transid)
 {
 	struct extent_io_tree *io_tree;
 	int ret;
@@ -254,7 +254,8 @@
 		WARN_ON(1);
 	}
 	eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
-	ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE);
+	ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
+					     btrfs_header_generation(eb));
 	BUG_ON(ret);
 	btrfs_clear_buffer_defrag(eb);
 	found_start = btrfs_header_bytenr(eb);
@@ -562,7 +563,8 @@
 	.sync_page	= block_sync_page,
 };
  
-int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
+int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
+			 u64 parent_transid)
 {
 	struct extent_buffer *buf = NULL;
 	struct inode *btree_inode = root->fs_info->btree_inode;
@@ -592,12 +594,6 @@
 	return 0;
 }
  
-int btrfs_verify_block_csum(struct btrfs_root *root,
-			    struct extent_buffer *buf)
-{
-	return btrfs_buffer_uptodate(buf);
-}
-
 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 					    u64 bytenr, u32 blocksize)
 {
@@ -621,7 +617,7 @@
  
  
 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
-				      u32 blocksize)
+				      u32 blocksize, u64 parent_transid)
 {
 	struct extent_buffer *buf = NULL;
 	struct inode *btree_inode = root->fs_info->btree_inode;
@@ -634,7 +630,7 @@
 	if (!buf)
 		return NULL;
  
-	ret = btree_read_extent_buffer_pages(root, buf, 0);
+	ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
  
 	if (ret == 0) {
 		buf->flags |= EXTENT_UPTODATE;
@@ -715,7 +711,7 @@
  
 	blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 	root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
-				     blocksize);
+				     blocksize, 0);
 	BUG_ON(!root->node);
 	return 0;
 }
@@ -771,7 +767,7 @@
 	}
 	blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 	root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
-				     blocksize);
+				     blocksize, 0);
 	BUG_ON(!root->node);
 insert:
 	root->ref_cows = 1;
@@ -1288,7 +1284,7 @@
  
 	chunk_root->node = read_tree_block(chunk_root,
 					   btrfs_super_chunk_root(disk_super),
-					   blocksize);
+					   blocksize, 0);
 	BUG_ON(!chunk_root->node);
  
 	read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
@@ -1304,7 +1300,7 @@
  
 	tree_root->node = read_tree_block(tree_root,
 					  btrfs_super_root(disk_super),
-					  blocksize);
+					  blocksize, 0);
 	if (!tree_root->node)
 		goto fail_sb_buffer;
  
  
@@ -1732,11 +1728,11 @@
 		     EXTENT_DEFRAG, GFP_NOFS);
 }
  
-int btrfs_read_buffer(struct extent_buffer *buf)
+int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
 {
 	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
 	int ret;
-	ret = btree_read_extent_buffer_pages(root, buf, 0);
+	ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
 	if (ret == 0) {
 		buf->flags |= EXTENT_UPTODATE;
 	}
@@ -25,8 +25,9 @@
 struct btrfs_fs_devices;
  
 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
-				      u32 blocksize);
-int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize);
+				      u32 blocksize, u64 parent_transid);
+int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
+			 u64 parent_transid);
 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 						   u64 bytenr, u32 blocksize);
 int clean_tree_block(struct btrfs_trans_handle *trans,
@@ -65,7 +66,7 @@
 int btrfs_buffer_defrag_done(struct extent_buffer *buf);
 int btrfs_clear_buffer_defrag(struct extent_buffer *buf);
 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf);
-int btrfs_read_buffer(struct extent_buffer *buf);
+int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len);
 void btrfs_csum_final(u32 crc, char *result);
 void btrfs_throttle(struct btrfs_root *root);
@@ -1338,7 +1338,8 @@
 					&extent_item, sizeof(extent_item));
 		clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
 				  GFP_NOFS);
-		eb = read_tree_block(extent_root, ins.objectid, ins.offset);
+		eb = read_tree_block(extent_root, ins.objectid, ins.offset,
+				     trans->transid);
 		level = btrfs_header_level(eb);
 		if (level == 0) {
 			btrfs_item_key(eb, &first, 0);
@@ -2076,7 +2077,8 @@
 			}
 		}
 		mutex_unlock(&root->fs_info->fs_mutex);
-		ret = readahead_tree_block(root, bytenr, blocksize);
+		ret = readahead_tree_block(root, bytenr, blocksize,
+					   btrfs_node_ptr_generation(node, i));
 		last = bytenr + blocksize;
 		cond_resched();
 		mutex_lock(&root->fs_info->fs_mutex);
@@ -2096,6 +2098,7 @@
 	u64 root_owner;
 	u64 root_gen;
 	u64 bytenr;
+	u64 ptr_gen;
 	struct extent_buffer *next;
 	struct extent_buffer *cur;
 	struct extent_buffer *parent;
@@ -2132,6 +2135,7 @@
 			break;
 		}
 		bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
+		ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
 		blocksize = btrfs_level_size(root, *level - 1);
 		ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
 		BUG_ON(ret);
@@ -2152,7 +2156,8 @@
 			reada_walk_down(root, cur, path->slots[*level]);
  
 			mutex_unlock(&root->fs_info->fs_mutex);
-			next = read_tree_block(root, bytenr, blocksize);
+			next = read_tree_block(root, bytenr, blocksize,
+					       ptr_gen);
 			mutex_lock(&root->fs_info->fs_mutex);
  
 			/* we've dropped the lock, double check */
@@ -2173,8 +2178,6 @@
 				BUG_ON(ret);
 				continue;
 			}
-		} else if (next) {
-			btrfs_verify_block_csum(root, next);
 		}
 		WARN_ON(*level <= 0);
 		if (path->nodes[*level-1])
@@ -2609,7 +2612,7 @@
 		int i;
  
 		eb = read_tree_block(found_root, extent_key->objectid,
-				     extent_key->offset);
+				     extent_key->offset, 0);
 		level = btrfs_header_level(eb);
  
 		if (level == 0)
@@ -186,7 +186,8 @@
 	for (i = 0; i < nr; i++) {
 		struct extent_buffer *next = read_tree_block(root,
 					btrfs_node_blockptr(c, i),
-					btrfs_level_size(root, level - 1));
+					btrfs_level_size(root, level - 1),
+					btrfs_node_ptr_generation(c, i));
 		if (btrfs_is_leaf(next) &&
 		    btrfs_header_level(c) != 1)
 			BUG();
@@ -28,6 +28,7 @@
 	int i;
 	u32 nritems;
 	u64 bytenr;
+	u64 gen;
 	u32 blocksize;
 	int ret;
  
@@ -35,7 +36,8 @@
 	nritems = btrfs_header_nritems(node);
 	for (i = 0; i < nritems; i++) {
 		bytenr = btrfs_node_blockptr(node, i);
-		ret = readahead_tree_block(root, bytenr, blocksize);
+		gen = btrfs_node_ptr_generation(node, i);
+		ret = readahead_tree_block(root, bytenr, blocksize, gen);
 		if (ret)
 			break;
 	}
  
@@ -101,10 +103,11 @@
 				path->slots[*level]++;
 				continue;
 			}
-			btrfs_verify_block_csum(root, next);
 		} else {
 			next = read_tree_block(root, bytenr,
-				       btrfs_level_size(root, *level - 1));
+				       btrfs_level_size(root, *level - 1),
+				       btrfs_node_ptr_generation(cur,
+							 path->slots[*level]));
 		}
 		ret = btrfs_cow_block(trans, root, next, path->nodes[*level],
 				      path->slots[*level], &next);
...	...	@@ -302,6 +302,7 @@
302	302	struct extent_buffer *cur;
303	303	struct extent_buffer *tmp;
304	304	u64 blocknr;
	305	+ u64 gen;
305	306	u64 search_start = *last_ret;
306	307	u64 last_block = 0;
307	308	u64 other;
...	...	@@ -354,6 +355,7 @@
354	355
355	356	progress_passed = 1;
356	357	blocknr = btrfs_node_blockptr(parent, i);
	358	+ gen = btrfs_node_ptr_generation(parent, i);
357	359	if (last_block == 0)
358	360	last_block = blocknr;
359	361
360	362
361	363
...	...	@@ -387,15 +389,14 @@
387	389	}
388	390	if (!cur) {
389	391	cur = read_tree_block(root, blocknr,
390		- blocksize);
	392	+ blocksize, gen);
391	393	} else if (!uptodate) {
392		- btrfs_read_buffer(cur);
	394	+ btrfs_read_buffer(cur, gen);
393	395	}
394	396	}
395	397	if (search_start == 0)
396	398	search_start = last_block;
397	399
398		- btrfs_verify_block_csum(root, cur);
399	400	err = __btrfs_cow_block(trans, root, cur, parent, i,
400	401	&tmp, search_start,
401	402	min(16 * blocksize,
402	403
403	404
...	...	@@ -696,12 +697,17 @@
696	697	static struct extent_buffer read_node_slot(struct btrfs_root root,
697	698	struct extent_buffer *parent, int slot)
698	699	{
	700	+ int level = btrfs_header_level(parent);
699	701	if (slot < 0)
700	702	return NULL;
701	703	if (slot >= btrfs_header_nritems(parent))
702	704	return NULL;
	705	+
	706	+ BUG_ON(level == 0);
	707	+
703	708	return read_tree_block(root, btrfs_node_blockptr(parent, slot),
704		- btrfs_level_size(root, btrfs_header_level(parent) - 1));
	709	+ btrfs_level_size(root, level - 1),
	710	+ btrfs_node_ptr_generation(parent, slot));
705	711	}
706	712
707	713	static int balance_level(struct btrfs_trans_handle *trans,
...	...	@@ -1076,7 +1082,8 @@
1076	1082	if ((search >= lowest_read && search <= highest_read) \|\|
1077	1083	(search < lowest_read && lowest_read - search <= 32768) \|\|
1078	1084	(search > highest_read && search - highest_read <= 32768)) {
1079		- readahead_tree_block(root, search, blocksize);
	1085	+ readahead_tree_block(root, search, blocksize,
	1086	+ btrfs_node_ptr_generation(node, nr));
1080	1087	nread += blocksize;
1081	1088	}
1082	1089	nscan++;
...	...	@@ -1109,8 +1116,6 @@
1109	1116	ins_len, int cow)
1110	1117	{
1111	1118	struct extent_buffer *b;
1112		- u64 bytenr;
1113		- u64 ptr_gen;
1114	1119	int slot;
1115	1120	int ret;
1116	1121	int level;
1117	1122
...	...	@@ -1174,20 +1179,12 @@
1174	1179	/* this is only true while dropping a snapshot */
1175	1180	if (level == lowest_level)
1176	1181	break;
1177		- bytenr = btrfs_node_blockptr(b, slot);
1178		- ptr_gen = btrfs_node_ptr_generation(b, slot);
	1182	+
1179	1183	if (should_reada)
1180	1184	reada_for_search(root, p, level, slot,
1181	1185	key->objectid);
1182		- b = read_tree_block(root, bytenr,
1183		- btrfs_level_size(root, level - 1));
1184		- if (ptr_gen != btrfs_header_generation(b)) {
1185		- printk("block %llu bad gen wanted %llu "
1186		- "found %llu\n",
1187		- (unsigned long long)b->start,
1188		- (unsigned long long)ptr_gen,
1189		- (unsigned long long)btrfs_header_generation(b));
1190		- }
	1186	+
	1187	+ b = read_node_slot(root, b, slot);
1191	1188	} else {
1192	1189	p->slots[level] = slot;
1193	1190	if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
...	...	@@ -1650,8 +1647,7 @@
1650	1647	if (slot >= btrfs_header_nritems(upper) - 1)
1651	1648	return 1;
1652	1649
1653		- right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
1654		- root->leafsize);
	1650	+ right = read_node_slot(root, upper, slot + 1);
1655	1651	free_space = btrfs_leaf_free_space(root, right);
1656	1652	if (free_space < data_size + sizeof(struct btrfs_item)) {
1657	1653	free_extent_buffer(right);
...	...	@@ -1826,8 +1822,7 @@
1826	1822	return 1;
1827	1823	}
1828	1824
1829		- left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
1830		- slot - 1), root->leafsize);
	1825	+ left = read_node_slot(root, path->nodes[1], slot - 1);
1831	1826	free_space = btrfs_leaf_free_space(root, left);
1832	1827	if (free_space < data_size + sizeof(struct btrfs_item)) {
1833	1828	free_extent_buffer(left);
...	...	@@ -2742,7 +2737,6 @@
2742	2737	*/
2743	2738	int btrfs_prev_leaf(struct btrfs_root root, struct btrfs_path path)
2744	2739	{
2745		- u64 bytenr;
2746	2740	int slot;
2747	2741	int level = 1;
2748	2742	struct extent_buffer *c;
2749	2743
...	...	@@ -2762,12 +2756,10 @@
2762	2756	}
2763	2757	slot--;
2764	2758
2765		- bytenr = btrfs_node_blockptr(c, slot);
2766	2759	if (next)
2767	2760	free_extent_buffer(next);
2768	2761
2769		- next = read_tree_block(root, bytenr,
2770		- btrfs_level_size(root, level - 1));
	2762	+ next = read_node_slot(root, c, slot);
2771	2763	break;
2772	2764	}
2773	2765	path->slots[level] = slot;
...	...	@@ -2782,8 +2774,7 @@
2782	2774	path->slots[level] = slot;
2783	2775	if (!level)
2784	2776	break;
2785		- next = read_tree_block(root, btrfs_node_blockptr(next, slot),
2786		- btrfs_level_size(root, level - 1));
	2777	+ next = read_node_slot(root, next, slot);
2787	2778	}
2788	2779	return 0;
2789	2780	}
...	...	@@ -2797,7 +2788,6 @@
2797	2788	{
2798	2789	int slot;
2799	2790	int level = 1;
2800		- u64 bytenr;
2801	2791	struct extent_buffer *c;
2802	2792	struct extent_buffer *next = NULL;
2803	2793
2804	2794
...	...	@@ -2814,15 +2804,13 @@
2814	2804	continue;
2815	2805	}
2816	2806
2817		- bytenr = btrfs_node_blockptr(c, slot);
2818	2807	if (next)
2819	2808	free_extent_buffer(next);
2820	2809
2821	2810	if (path->reada)
2822	2811	reada_for_search(root, path, level, slot, 0);
2823	2812
2824		- next = read_tree_block(root, bytenr,
2825		- btrfs_level_size(root, level -1));
	2813	+ next = read_node_slot(root, c, slot);
2826	2814	break;
2827	2815	}
2828	2816	path->slots[level] = slot;
...	...	@@ -2836,8 +2824,7 @@
2836	2824	break;
2837	2825	if (path->reada)
2838	2826	reada_for_search(root, path, level, 0, 0);
2839		- next = read_tree_block(root, btrfs_node_blockptr(next, 0),
2840		- btrfs_level_size(root, level - 1));
	2827	+ next = read_node_slot(root, next, 0);
2841	2828	}
2842	2829	return 0;
2843	2830	}
...	...	@@ -207,7 +207,7 @@
207	207
208	208	static int btree_read_extent_buffer_pages(struct btrfs_root *root,
209	209	struct extent_buffer *eb,
210		- u64 start)
	210	+ u64 start, u64 parent_transid)
211	211	{
212	212	struct extent_io_tree *io_tree;
213	213	int ret;
...	...	@@ -254,7 +254,8 @@
254	254	WARN_ON(1);
255	255	}
256	256	eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
257		- ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE);
	257	+ ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
	258	+ btrfs_header_generation(eb));
258	259	BUG_ON(ret);
259	260	btrfs_clear_buffer_defrag(eb);
260	261	found_start = btrfs_header_bytenr(eb);
...	...	@@ -562,7 +563,8 @@
562	563	.sync_page = block_sync_page,
563	564	};
564	565
565		-int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
	566	+int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
	567	+ u64 parent_transid)
566	568	{
567	569	struct extent_buffer *buf = NULL;
568	570	struct inode *btree_inode = root->fs_info->btree_inode;
...	...	@@ -592,12 +594,6 @@
592	594	return 0;
593	595	}
594	596
595		-int btrfs_verify_block_csum(struct btrfs_root *root,
596		- struct extent_buffer *buf)
597		-{
598		- return btrfs_buffer_uptodate(buf);
599		-}
600		-
601	597	struct extent_buffer btrfs_find_tree_block(struct btrfs_root root,
602	598	u64 bytenr, u32 blocksize)
603	599	{
...	...	@@ -621,7 +617,7 @@
621	617
622	618
623	619	struct extent_buffer read_tree_block(struct btrfs_root root, u64 bytenr,
624		- u32 blocksize)
	620	+ u32 blocksize, u64 parent_transid)
625	621	{
626	622	struct extent_buffer *buf = NULL;
627	623	struct inode *btree_inode = root->fs_info->btree_inode;
...	...	@@ -634,7 +630,7 @@
634	630	if (!buf)
635	631	return NULL;
636	632
637		- ret = btree_read_extent_buffer_pages(root, buf, 0);
	633	+ ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
638	634
639	635	if (ret == 0) {
640	636	buf->flags \|= EXTENT_UPTODATE;
...	...	@@ -715,7 +711,7 @@
715	711
716	712	blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
717	713	root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
718		- blocksize);
	714	+ blocksize, 0);
719	715	BUG_ON(!root->node);
720	716	return 0;
721	717	}
...	...	@@ -771,7 +767,7 @@
771	767	}
772	768	blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
773	769	root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
774		- blocksize);
	770	+ blocksize, 0);
775	771	BUG_ON(!root->node);
776	772	insert:
777	773	root->ref_cows = 1;
...	...	@@ -1288,7 +1284,7 @@
1288	1284
1289	1285	chunk_root->node = read_tree_block(chunk_root,
1290	1286	btrfs_super_chunk_root(disk_super),
1291		- blocksize);
	1287	+ blocksize, 0);
1292	1288	BUG_ON(!chunk_root->node);
1293	1289
1294	1290	read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
...	...	@@ -1304,7 +1300,7 @@
1304	1300
1305	1301	tree_root->node = read_tree_block(tree_root,
1306	1302	btrfs_super_root(disk_super),
1307		- blocksize);
	1303	+ blocksize, 0);
1308	1304	if (!tree_root->node)
1309	1305	goto fail_sb_buffer;
1310	1306
1311	1307
...	...	@@ -1732,11 +1728,11 @@
1732	1728	EXTENT_DEFRAG, GFP_NOFS);
1733	1729	}
1734	1730
1735		-int btrfs_read_buffer(struct extent_buffer *buf)
	1731	+int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
1736	1732	{
1737	1733	struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1738	1734	int ret;
1739		- ret = btree_read_extent_buffer_pages(root, buf, 0);
	1735	+ ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1740	1736	if (ret == 0) {
1741	1737	buf->flags \|= EXTENT_UPTODATE;
1742	1738	}
...	...	@@ -25,8 +25,9 @@
25	25	struct btrfs_fs_devices;
26	26
27	27	struct extent_buffer read_tree_block(struct btrfs_root root, u64 bytenr,
28		- u32 blocksize);
29		-int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize);
	28	+ u32 blocksize, u64 parent_transid);
	29	+int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
	30	+ u64 parent_transid);
30	31	struct extent_buffer btrfs_find_create_tree_block(struct btrfs_root root,
31	32	u64 bytenr, u32 blocksize);
32	33	int clean_tree_block(struct btrfs_trans_handle *trans,
...	...	@@ -65,7 +66,7 @@
65	66	int btrfs_buffer_defrag_done(struct extent_buffer *buf);
66	67	int btrfs_clear_buffer_defrag(struct extent_buffer *buf);
67	68	int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf);
68		-int btrfs_read_buffer(struct extent_buffer *buf);
	69	+int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid);
69	70	u32 btrfs_csum_data(struct btrfs_root root, char data, u32 seed, size_t len);
70	71	void btrfs_csum_final(u32 crc, char *result);
71	72	void btrfs_throttle(struct btrfs_root *root);
...	...	@@ -1338,7 +1338,8 @@
1338	1338	&extent_item, sizeof(extent_item));
1339	1339	clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED,
1340	1340	GFP_NOFS);
1341		- eb = read_tree_block(extent_root, ins.objectid, ins.offset);
	1341	+ eb = read_tree_block(extent_root, ins.objectid, ins.offset,
	1342	+ trans->transid);
1342	1343	level = btrfs_header_level(eb);
1343	1344	if (level == 0) {
1344	1345	btrfs_item_key(eb, &first, 0);
...	...	@@ -2076,7 +2077,8 @@
2076	2077	}
2077	2078	}
2078	2079	mutex_unlock(&root->fs_info->fs_mutex);
2079		- ret = readahead_tree_block(root, bytenr, blocksize);
	2080	+ ret = readahead_tree_block(root, bytenr, blocksize,
	2081	+ btrfs_node_ptr_generation(node, i));
2080	2082	last = bytenr + blocksize;
2081	2083	cond_resched();
2082	2084	mutex_lock(&root->fs_info->fs_mutex);
...	...	@@ -2096,6 +2098,7 @@
2096	2098	u64 root_owner;
2097	2099	u64 root_gen;
2098	2100	u64 bytenr;
	2101	+ u64 ptr_gen;
2099	2102	struct extent_buffer *next;
2100	2103	struct extent_buffer *cur;
2101	2104	struct extent_buffer *parent;
...	...	@@ -2132,6 +2135,7 @@
2132	2135	break;
2133	2136	}
2134	2137	bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
	2138	+ ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2135	2139	blocksize = btrfs_level_size(root, *level - 1);
2136	2140	ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs);
2137	2141	BUG_ON(ret);
...	...	@@ -2152,7 +2156,8 @@
2152	2156	reada_walk_down(root, cur, path->slots[*level]);
2153	2157
2154	2158	mutex_unlock(&root->fs_info->fs_mutex);
2155		- next = read_tree_block(root, bytenr, blocksize);
	2159	+ next = read_tree_block(root, bytenr, blocksize,
	2160	+ ptr_gen);
2156	2161	mutex_lock(&root->fs_info->fs_mutex);
2157	2162
2158	2163	/* we've dropped the lock, double check */
...	...	@@ -2173,8 +2178,6 @@
2173	2178	BUG_ON(ret);
2174	2179	continue;
2175	2180	}
2176		- } else if (next) {
2177		- btrfs_verify_block_csum(root, next);
2178	2181	}
2179	2182	WARN_ON(*level <= 0);
2180	2183	if (path->nodes[*level-1])
...	...	@@ -2609,7 +2612,7 @@
2609	2612	int i;
2610	2613
2611	2614	eb = read_tree_block(found_root, extent_key->objectid,
2612		- extent_key->offset);
	2615	+ extent_key->offset, 0);
2613	2616	level = btrfs_header_level(eb);
2614	2617
2615	2618	if (level == 0)
...	...	@@ -186,7 +186,8 @@
186	186	for (i = 0; i < nr; i++) {
187	187	struct extent_buffer *next = read_tree_block(root,
188	188	btrfs_node_blockptr(c, i),
189		- btrfs_level_size(root, level - 1));
	189	+ btrfs_level_size(root, level - 1),
	190	+ btrfs_node_ptr_generation(c, i));
190	191	if (btrfs_is_leaf(next) &&
191	192	btrfs_header_level(c) != 1)
192	193	BUG();
...	...	@@ -28,6 +28,7 @@
28	28	int i;
29	29	u32 nritems;
30	30	u64 bytenr;
	31	+ u64 gen;
31	32	u32 blocksize;
32	33	int ret;
33	34
...	...	@@ -35,7 +36,8 @@
35	36	nritems = btrfs_header_nritems(node);
36	37	for (i = 0; i < nritems; i++) {
37	38	bytenr = btrfs_node_blockptr(node, i);
38		- ret = readahead_tree_block(root, bytenr, blocksize);
	39	+ gen = btrfs_node_ptr_generation(node, i);
	40	+ ret = readahead_tree_block(root, bytenr, blocksize, gen);
39	41	if (ret)
40	42	break;
41	43	}
42	44
...	...	@@ -101,10 +103,11 @@
101	103	path->slots[*level]++;
102	104	continue;
103	105	}
104		- btrfs_verify_block_csum(root, next);
105	106	} else {
106	107	next = read_tree_block(root, bytenr,
107		- btrfs_level_size(root, *level - 1));
	108	+ btrfs_level_size(root, *level - 1),
	109	+ btrfs_node_ptr_generation(cur,
	110	+ path->slots[*level]));
108	111	}
109	112	ret = btrfs_cow_block(trans, root, next, path->nodes[*level],
110	113	path->slots[*level], &next);