Fix unused-but-set errors in gcc-4.6

gcc-4.6 (as shipped in Fedora) turns on -Wunused-but-set-variable by
default, which breaks the build when combined with -Wall, e.g.:

debug-tree.c: In function ‘print_extent_leaf’:
debug-tree.c:45:13: error: variable ‘last_len’ set but not used [-Werror=unused-but-set-variable]
debug-tree.c:44:13: error: variable ‘last’ set but not used [-Werror=unused-but-set-variable]
debug-tree.c:41:21: error: variable ‘item’ set but not used [-Werror=unused-but-set-variable]
cc1: all warnings being treated as errors

This patch fixes the errors by removing the unused variables.

Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Hugo Mills <hugo@carfax.org.uk>

btrfs-map-logical.c

@@ -41,7 +41,6 @@ struct extent_buffer *debug_read_block(struct btrfs_root *root, u64 bytenr,
 				     u32 blocksize, int copy)
 {
 	int ret;
-	int dev_nr;
 	struct extent_buffer *eb;
 	u64 length;
 	struct btrfs_multi_bio *multi = NULL;
@@ -53,7 +52,6 @@ struct extent_buffer *debug_read_block(struct btrfs_root *root, u64 bytenr,
 	if (!eb)
 		return NULL;
 
-	dev_nr = 0;
 	length = blocksize;
 	while (1) {
 		ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,

btrfsck.c

@@ -1037,7 +1037,7 @@ static int process_one_leaf(struct btrfs_root *root, struct extent_buffer *eb,
 			break;
 		};
 	}
-	return 0;
+	return ret;
 }
 
 static void reada_walk_down(struct btrfs_root *root,
@@ -1917,7 +1917,6 @@ static int check_owner_ref(struct btrfs_root *root,
 	struct btrfs_root *ref_root;
 	struct btrfs_key key;
 	struct btrfs_path path;
-	int ret;
 	int level;
 	int found = 0;
 
@@ -1950,7 +1949,7 @@ static int check_owner_ref(struct btrfs_root *root,
 	
 	btrfs_init_path(&path);
 	path.lowest_level = level + 1;
-	ret = btrfs_search_slot(NULL, ref_root, &key, &path, 0, 0);
+	btrfs_search_slot(NULL, ref_root, &key, &path, 0, 0);
 
 	if (buf->start == btrfs_node_blockptr(path.nodes[level + 1],
 					      path.slots[level + 1]))
@@ -2539,16 +2538,6 @@ static int run_next_block(struct btrfs_root *root,
 				continue;
 			}
 			if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
-				struct btrfs_block_group_item *bi;
-				bi = btrfs_item_ptr(buf, i,
-					    struct btrfs_block_group_item);
-#if 0
-				fprintf(stderr,"block group %Lu %Lu used %Lu ",
-					btrfs_disk_key_objectid(disk_key),
-					btrfs_disk_key_offset(disk_key),
-					btrfs_block_group_used(bi));
-				fprintf(stderr, "flags %x\n", bi->flags);
-#endif
 				continue;
 			}
 			if (key.type == BTRFS_EXTENT_REF_V0_KEY) {

ctree.c

@@ -262,7 +262,6 @@ int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 			     struct extent_buffer **cow_ret,
 			     u64 search_start, u64 empty_size)
 {
-	u64 generation;
 	struct extent_buffer *cow;
 	struct btrfs_disk_key disk_key;
 	int level;
@@ -272,7 +271,6 @@ int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 	WARN_ON(root->ref_cows && trans->transid != root->last_trans);
 
 	level = btrfs_header_level(buf);
-	generation = btrfs_header_generation(buf);
 
 	if (level == 0)
 		btrfs_item_key(buf, &disk_key, 0);
@@ -795,7 +793,6 @@ static int balance_level(struct btrfs_trans_handle *trans,
 	int wret;
 	int pslot;
 	int orig_slot = path->slots[level];
-	int err_on_enospc = 0;
 	u64 orig_ptr;
 
 	if (level == 0)
@@ -845,9 +842,6 @@ static int balance_level(struct btrfs_trans_handle *trans,
 	    BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
 		return 0;
 
-	if (btrfs_header_nritems(mid) < 2)
-		err_on_enospc = 1;
-
 	left = read_node_slot(root, parent, pslot - 1);
 	if (left) {
 		wret = btrfs_cow_block(trans, root, left,
@@ -873,8 +867,6 @@ static int balance_level(struct btrfs_trans_handle *trans,
 		wret = push_node_left(trans, root, left, mid, 1);
 		if (wret < 0)
 			ret = wret;
-		if (btrfs_header_nritems(mid) < 2)
-			err_on_enospc = 1;
 	}
 
 	/*
@@ -996,14 +988,12 @@ static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
 	int wret;
 	int pslot;
 	int orig_slot = path->slots[level];
-	u64 orig_ptr;
 
 	if (level == 0)
 		return 1;
 
 	mid = path->nodes[level];
 	WARN_ON(btrfs_header_generation(mid) != trans->transid);
-	orig_ptr = btrfs_node_blockptr(mid, orig_slot);
 
 	if (level < BTRFS_MAX_LEVEL - 1)
 		parent = path->nodes[level + 1];
@@ -2370,7 +2360,6 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans,
 {
 	int ret = 0;
 	int slot;
-	int slot_orig;
 	struct extent_buffer *leaf;
 	struct btrfs_item *item;
 	u32 nritems;
@@ -2380,7 +2369,6 @@ int btrfs_truncate_item(struct btrfs_trans_handle *trans,
 	unsigned int size_diff;
 	int i;
 
-	slot_orig = path->slots[0];
 	leaf = path->nodes[0];
 	slot = path->slots[0];
 
@@ -2468,7 +2456,6 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
 {
 	int ret = 0;
 	int slot;
-	int slot_orig;
 	struct extent_buffer *leaf;
 	struct btrfs_item *item;
 	u32 nritems;
@@ -2477,7 +2464,6 @@ int btrfs_extend_item(struct btrfs_trans_handle *trans,
 	unsigned int old_size;
 	int i;
 
-	slot_orig = path->slots[0];
 	leaf = path->nodes[0];
 
 	nritems = btrfs_header_nritems(leaf);
@@ -2541,7 +2527,6 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
 	struct btrfs_item *item;
 	int ret = 0;
 	int slot;
-	int slot_orig;
 	int i;
 	u32 nritems;
 	u32 total_size = 0;
@@ -2565,7 +2550,6 @@ int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
 	if (ret < 0)
 		goto out;
 
-	slot_orig = path->slots[0];
 	leaf = path->nodes[0];
 
 	nritems = btrfs_header_nritems(leaf);

debug-tree.c

@@ -35,44 +35,6 @@ static int print_usage(void)
 	exit(1);
 }
 
-static void print_extent_leaf(struct btrfs_root *root, struct extent_buffer *l)
-{
-	int i;
-	struct btrfs_item *item;
-//	struct btrfs_extent_ref *ref;
-	struct btrfs_key key;
-	static u64 last = 0;
-	static u64 last_len = 0;
-	u32 nr = btrfs_header_nritems(l);
-	u32 type;
-
-	for (i = 0 ; i < nr ; i++) {
-		item = btrfs_item_nr(l, i);
-		btrfs_item_key_to_cpu(l, &key, i);
-		type = btrfs_key_type(&key);
-		switch (type) {
-		case BTRFS_EXTENT_ITEM_KEY:
-			last_len = key.offset;
-			last = key.objectid;
-			break;
-#if 0
-		case BTRFS_EXTENT_REF_KEY:
-			ref = btrfs_item_ptr(l, i, struct btrfs_extent_ref);
-			printf("%llu %llu extent back ref root %llu gen %llu "
-			       "owner %llu num_refs %lu\n",
-			       (unsigned long long)last,
-			       (unsigned long long)last_len,
-			       (unsigned long long)btrfs_ref_root(l, ref),
-			       (unsigned long long)btrfs_ref_generation(l, ref),
-			       (unsigned long long)btrfs_ref_objectid(l, ref),
-			       (unsigned long)btrfs_ref_num_refs(l, ref));
-			break;
-#endif
-		};
-		fflush(stdout);
-	}
-}
-
 static void print_extents(struct btrfs_root *root, struct extent_buffer *eb)
 {
 	int i;
@@ -81,10 +43,7 @@ static void print_extents(struct btrfs_root *root, struct extent_buffer *eb)
 
 	if (!eb)
 		return;
-	if (btrfs_is_leaf(eb)) {
+
-		print_extent_leaf(root, eb);
-		return;
-	}
 	size = btrfs_level_size(root, btrfs_header_level(eb) - 1);
 	nr = btrfs_header_nritems(eb);
 	for (i = 0; i < nr; i++) {

dir-item.c

@@ -332,5 +332,5 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 		ret = btrfs_truncate_item(trans, root, path,
 					  item_len - sub_item_len, 1);
 	}
-	return 0;
+	return ret;
 }

disk-io.c

@@ -123,7 +123,6 @@ int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 			 u64 parent_transid)
 {
 	int ret;
-	int dev_nr;
 	struct extent_buffer *eb;
 	u64 length;
 	struct btrfs_multi_bio *multi = NULL;
@@ -135,7 +134,6 @@ int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
 		return 0;
 	}
 
-	dev_nr = 0;
 	length = blocksize;
 	ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
 			      bytenr, &length, &multi, 0);
@@ -177,7 +175,6 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 				     u32 blocksize, u64 parent_transid)
 {
 	int ret;
-	int dev_nr;
 	struct extent_buffer *eb;
 	u64 length;
 	struct btrfs_multi_bio *multi = NULL;
@@ -192,7 +189,6 @@ struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 	if (btrfs_buffer_uptodate(eb, parent_transid))
 		return eb;
 
-	dev_nr = 0;
 	length = blocksize;
 	while (1) {
 		ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,

extent-cache.c

@@ -96,13 +96,11 @@ int insert_existing_cache_extent(struct cache_tree *tree,
 				 struct cache_extent *pe)
 {
 	struct rb_node *found;
-	struct cache_extent *entry;
 
 	found = tree_insert(&tree->root, pe->start, pe->size, &pe->rb_node);
-	if (found) {
+	if (found)
-		entry = rb_entry(found, struct cache_extent, rb_node);
 		return -EEXIST;
-	}
+
 	return 0;
 }
 

extent-tree.c

@@ -1549,7 +1549,6 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
 	int i;
 	int level;
 	int ret = 0;
-	int faili = 0;
 	int (*process_func)(struct btrfs_trans_handle *trans,
 			    struct btrfs_root *root,
 			    u64, u64, u64, u64, u64, u64);
@@ -1592,7 +1591,6 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
 					   parent, ref_root, key.objectid,
 					   key.offset);
 			if (ret) {
-				faili = i;
 				WARN_ON(1);
 				goto fail;
 			}
@@ -1602,7 +1600,6 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
 			ret = process_func(trans, root, bytenr, num_bytes,
 					   parent, ref_root, level - 1, 0);
 			if (ret) {
-				faili = i;
 				WARN_ON(1);
 				goto fail;
 			}
@@ -1611,33 +1608,6 @@ static int __btrfs_mod_ref(struct btrfs_trans_handle *trans,
 	return 0;
 fail:
 	WARN_ON(1);
-#if 0
-	for (i =0; i < faili; i++) {
-		if (level == 0) {
-			u64 disk_bytenr;
-			btrfs_item_key_to_cpu(buf, &key, i);
-			if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
-				continue;
-			fi = btrfs_item_ptr(buf, i,
-					    struct btrfs_file_extent_item);
-			if (btrfs_file_extent_type(buf, fi) ==
-			    BTRFS_FILE_EXTENT_INLINE)
-				continue;
-			disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi);
-			if (disk_bytenr == 0)
-				continue;
-			err = btrfs_free_extent(trans, root, disk_bytenr,
-				    btrfs_file_extent_disk_num_bytes(buf,
-								      fi), 0);
-			BUG_ON(err);
-		} else {
-			bytenr = btrfs_node_blockptr(buf, i);
-			err = btrfs_free_extent(trans, root, bytenr,
-					btrfs_level_size(root, level - 1), 0);
-			BUG_ON(err);
-		}
-	}
-#endif
 	return ret;
 }
 

extent_io.c

@@ -296,7 +296,6 @@ int set_extent_bits(struct extent_io_tree *tree, u64 start,
 	struct extent_state *prealloc = NULL;
 	struct cache_extent *node;
 	int err = 0;
-	int set;
 	u64 last_start;
 	u64 last_end;
 again:
@@ -327,7 +326,6 @@ again:
 	 * Just lock what we found and keep going
 	 */
 	if (state->start == start && state->end <= end) {
-		set = state->state & bits;
 		state->state |= bits;
 		merge_state(tree, state);
 		if (last_end == (u64)-1)
@@ -352,7 +350,6 @@ again:
 	 * desired bit on it.
 	 */
 	if (state->start < start) {
-		set = state->state & bits;
 		err = split_state(tree, state, prealloc, start);
 		BUG_ON(err == -EEXIST);
 		prealloc = NULL;
@@ -398,7 +395,6 @@ again:
 	 * We need to split the extent, and set the bit
 	 * on the first half
 	 */
-	set = state->state & bits;
 	err = split_state(tree, state, prealloc, end + 1);
 	BUG_ON(err == -EEXIST);
 

mkfs.c

@@ -1149,7 +1149,6 @@ int main(int ac, char **av)
 	int zero_end = 1;
 	int option_index = 0;
 	int fd;
-	int first_fd;
 	int ret;
 	int i;
 	int mixed = 0;
@@ -1250,7 +1249,6 @@ int main(int ac, char **av)
 			fprintf(stderr, "unable to open %s\n", file);
 			exit(1);
 		}
-		first_fd = fd;
 		first_file = file;
 		ret = btrfs_prepare_device(fd, file, zero_end, &dev_block_count, &mixed);
 		if (block_count == 0)
@@ -1264,7 +1262,6 @@ int main(int ac, char **av)
 		}
 
 		file = output;
-		first_fd = fd;
 		first_file = file;
 		block_count = size_sourcedir(source_dir, sectorsize,
 					     &num_of_meta_chunks, &size_of_data);

print-tree.c

@@ -444,7 +444,6 @@ void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l)
 	struct btrfs_dir_item *di;
 	struct btrfs_inode_item *ii;
 	struct btrfs_file_extent_item *fi;
-	struct btrfs_csum_item *ci;
 	struct btrfs_block_group_item *bi;
 	struct btrfs_extent_data_ref *dref;
 	struct btrfs_shared_data_ref *sref;
@@ -556,11 +555,9 @@ void btrfs_print_leaf(struct btrfs_root *root, struct extent_buffer *l)
 #endif
 			break;
 		case BTRFS_CSUM_ITEM_KEY:
-			ci = btrfs_item_ptr(l, i, struct btrfs_csum_item);
 			printf("\t\tcsum item\n");
 			break;
 		case BTRFS_EXTENT_CSUM_KEY:
-			ci = btrfs_item_ptr(l, i, struct btrfs_csum_item);
 			printf("\t\textent csum item\n");
 			break;
 		case BTRFS_EXTENT_DATA_KEY:

volumes.c

@@ -643,7 +643,6 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 	struct list_head *cur;
 	struct map_lookup *map;
 	int min_stripe_size = 1 * 1024 * 1024;
-	u64 physical;
 	u64 calc_size = 8 * 1024 * 1024;
 	u64 min_free;
 	u64 max_chunk_size = 4 * calc_size;
@@ -811,7 +810,6 @@ again:
 		btrfs_set_stack_stripe_devid(stripe, device->devid);
 		btrfs_set_stack_stripe_offset(stripe, dev_offset);
 		memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
-		physical = dev_offset;
 		index++;
 	}
 	BUG_ON(!list_empty(&private_devs));
@@ -971,14 +969,12 @@ int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
 	struct cache_extent *ce;
 	struct map_lookup *map;
 	int ret;
-	u64 offset;
 
 	ce = find_first_cache_extent(&map_tree->cache_tree, logical);
 	BUG_ON(!ce);
 	BUG_ON(ce->start > logical || ce->start + ce->size < logical);
 	map = container_of(ce, struct map_lookup, ce);
 
-	offset = logical - ce->start;
 	if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
 		ret = map->num_stripes;
 	else if (map->type & BTRFS_BLOCK_GROUP_RAID10)