btrfs: make find_first_extent_bit() return a boolean

Currently find_first_extent_bit() returns a 0 if it found a range in the
given io tree and 1 if it didn't find any. There's no need to return any
errors, so make the return value a boolean and invert the logic to make
more sense: return true if it found a range and false if it didn't find
any range.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/block-group.c

@@ -527,11 +527,10 @@ int btrfs_add_new_free_space(struct btrfs_block_group *block_group, u64 start,
 		*total_added_ret = 0;
 
 	while (start < end) {
-		ret = find_first_extent_bit(&info->excluded_extents, start,
-					    &extent_start, &extent_end,
-					    EXTENT_DIRTY | EXTENT_UPTODATE,
-					    NULL);
-		if (ret)
+		if (!find_first_extent_bit(&info->excluded_extents, start,
+					   &extent_start, &extent_end,
+					   EXTENT_DIRTY | EXTENT_UPTODATE,
+					   NULL))
 			break;
 
 		if (extent_start <= start) {

fs/btrfs/dev-replace.c

@@ -792,9 +792,9 @@ static int btrfs_set_target_alloc_state(struct btrfs_device *srcdev,
 
 	lockdep_assert_held(&srcdev->fs_info->chunk_mutex);
 
-	while (!find_first_extent_bit(&srcdev->alloc_state, start,
-				      &found_start, &found_end,
-				      CHUNK_ALLOCATED, &cached_state)) {
+	while (find_first_extent_bit(&srcdev->alloc_state, start,
+				     &found_start, &found_end,
+				     CHUNK_ALLOCATED, &cached_state)) {
 		ret = set_extent_bit(&tgtdev->alloc_state, found_start,
 				     found_end, CHUNK_ALLOCATED, NULL);
 		if (ret)

fs/btrfs/disk-io.c

@@ -4228,7 +4228,7 @@ static void warn_about_uncommitted_trans(struct btrfs_fs_info *fs_info)
 		u64 found_end;
 
 		found = true;
-		while (!find_first_extent_bit(&trans->dirty_pages, cur,
+		while (find_first_extent_bit(&trans->dirty_pages, cur,
 			&found_start, &found_end, EXTENT_DIRTY, &cached)) {
 			dirty_bytes += found_end + 1 - found_start;
 			cur = found_end + 1;
@@ -4724,8 +4724,8 @@ static void btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
 	u64 start = 0;
 	u64 end;
 
-	while (!find_first_extent_bit(dirty_pages, start, &start, &end,
-				      mark, NULL)) {
+	while (find_first_extent_bit(dirty_pages, start, &start, &end,
+				     mark, NULL)) {
 		clear_extent_bits(dirty_pages, start, end, mark);
 		while (start <= end) {
 			eb = find_extent_buffer(fs_info, start);
@@ -4759,8 +4759,8 @@ static void btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
 		 * the same extent range.
 		 */
 		mutex_lock(&fs_info->unused_bg_unpin_mutex);
-		if (find_first_extent_bit(unpin, 0, &start, &end,
-					  EXTENT_DIRTY, &cached_state)) {
+		if (!find_first_extent_bit(unpin, 0, &start, &end,
+					   EXTENT_DIRTY, &cached_state)) {
 			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
 			break;
 		}

fs/btrfs/extent-io-tree.c

@@ -831,15 +831,15 @@ static struct extent_state *find_first_extent_bit_state(struct extent_io_tree *t
  *
  * Note: If there are multiple bits set in @bits, any of them will match.
  *
- * Return 0 if we find something, and update @start_ret and @end_ret.
- * Return 1 if we found nothing.
+ * Return true if we find something, and update @start_ret and @end_ret.
+ * Return false if we found nothing.
  */
-int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
-			  u64 *start_ret, u64 *end_ret, u32 bits,
-			  struct extent_state **cached_state)
+bool find_first_extent_bit(struct extent_io_tree *tree, u64 start,
+			   u64 *start_ret, u64 *end_ret, u32 bits,
+			   struct extent_state **cached_state)
 {
 	struct extent_state *state;
-	int ret = 1;
+	bool ret = false;
 
 	spin_lock(&tree->lock);
 	if (cached_state && *cached_state) {
@@ -863,7 +863,7 @@ int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
 		cache_state_if_flags(state, cached_state, 0);
 		*start_ret = state->start;
 		*end_ret = state->end;
-		ret = 0;
+		ret = true;
 	}
 out:
 	spin_unlock(&tree->lock);

fs/btrfs/extent-io-tree.h

@@ -182,9 +182,9 @@ int convert_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
 		       u32 bits, u32 clear_bits,
 		       struct extent_state **cached_state);
 
-int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
-			  u64 *start_ret, u64 *end_ret, u32 bits,
-			  struct extent_state **cached_state);
+bool find_first_extent_bit(struct extent_io_tree *tree, u64 start,
+			   u64 *start_ret, u64 *end_ret, u32 bits,
+			   struct extent_state **cached_state);
 void find_first_clear_extent_bit(struct extent_io_tree *tree, u64 start,
 				 u64 *start_ret, u64 *end_ret, u32 bits);
 int find_contiguous_extent_bit(struct extent_io_tree *tree, u64 start,

fs/btrfs/extent-tree.c

@@ -2751,9 +2751,8 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
 		struct extent_state *cached_state = NULL;
 
 		mutex_lock(&fs_info->unused_bg_unpin_mutex);
-		ret = find_first_extent_bit(unpin, 0, &start, &end,
-					    EXTENT_DIRTY, &cached_state);
-		if (ret) {
+		if (!find_first_extent_bit(unpin, 0, &start, &end,
+					   EXTENT_DIRTY, &cached_state)) {
 			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
 			break;
 		}

fs/btrfs/free-space-cache.c

@@ -1219,10 +1219,9 @@ static noinline_for_stack int write_pinned_extent_entries(
 	start = block_group->start;
 
 	while (start < block_group->start + block_group->length) {
-		ret = find_first_extent_bit(unpin, start,
-					    &extent_start, &extent_end,
-					    EXTENT_DIRTY, NULL);
-		if (ret)
+		if (!find_first_extent_bit(unpin, start,
+					   &extent_start, &extent_end,
+					   EXTENT_DIRTY, NULL))
 			return 0;
 
 		/* This pinned extent is out of our range */

fs/btrfs/relocation.c

@@ -3498,6 +3498,8 @@ int find_next_extent(struct reloc_control *rc, struct btrfs_path *path,
 
 	last = rc->block_group->start + rc->block_group->length;
 	while (1) {
+		bool block_found;
+
 		cond_resched();
 		if (rc->search_start >= last) {
 			ret = 1;
@@ -3548,11 +3550,11 @@ int find_next_extent(struct reloc_control *rc, struct btrfs_path *path,
 			goto next;
 		}
 
-		ret = find_first_extent_bit(&rc->processed_blocks,
-					    key.objectid, &start, &end,
-					    EXTENT_DIRTY, NULL);
+		block_found = find_first_extent_bit(&rc->processed_blocks,
+						    key.objectid, &start, &end,
+						    EXTENT_DIRTY, NULL);
 
-		if (ret == 0 && start <= key.objectid) {
+		if (block_found && start <= key.objectid) {
 			btrfs_release_path(path);
 			rc->search_start = end + 1;
 		} else {

fs/btrfs/transaction.c

@@ -1060,8 +1060,8 @@ int btrfs_write_marked_extents(struct btrfs_fs_info *fs_info,
 	u64 start = 0;
 	u64 end;
 
-	while (!find_first_extent_bit(dirty_pages, start, &start, &end,
-				      mark, &cached_state)) {
+	while (find_first_extent_bit(dirty_pages, start, &start, &end,
+				     mark, &cached_state)) {
 		bool wait_writeback = false;
 
 		err = convert_extent_bit(dirty_pages, start, end,
@@ -1114,8 +1114,8 @@ static int __btrfs_wait_marked_extents(struct btrfs_fs_info *fs_info,
 	u64 start = 0;
 	u64 end;
 
-	while (!find_first_extent_bit(dirty_pages, start, &start, &end,
-				      EXTENT_NEED_WAIT, &cached_state)) {
+	while (find_first_extent_bit(dirty_pages, start, &start, &end,
+				     EXTENT_NEED_WAIT, &cached_state)) {
 		/*
 		 * Ignore -ENOMEM errors returned by clear_extent_bit().
 		 * When committing the transaction, we'll remove any entries

fs/btrfs/volumes.c

@@ -1424,9 +1424,9 @@ static bool contains_pending_extent(struct btrfs_device *device, u64 *start,
 
 	lockdep_assert_held(&device->fs_info->chunk_mutex);
 
-	if (!find_first_extent_bit(&device->alloc_state, *start,
-				   &physical_start, &physical_end,
-				   CHUNK_ALLOCATED, NULL)) {
+	if (find_first_extent_bit(&device->alloc_state, *start,
+				  &physical_start, &physical_end,
+				  CHUNK_ALLOCATED, NULL)) {
 
 		if (in_range(physical_start, *start, len) ||
 		    in_range(*start, physical_start,