[10/21] btrfs: return bool from lock_extent_buffer_for_io

Commit Message

[e-mail] March 14, 2023, 6:16 a.m. UTC

lock_extent_buffer_for_io never returns a negative error value, so switch
the return value to a simple bool.  Also remove the noinline_for_stack
annotation given that nothing in lock_extent_buffer_for_io or its callers
is particularly stack hungry.

Signed-off-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Johannes Thumshirn <[e-mail]>
---
 fs/btrfs/extent_io.c | 39 ++++++++++++---------------------------
 1 file changed, 12 insertions(+), 27 deletions(-)

Patch

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index bc50163dd3b792..08e4e53f42e8a7 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1628,18 +1628,17 @@  static void end_extent_buffer_writeback(struct extent_buffer *eb)
  *
  * May try to flush write bio if we can't get the lock.
  *
- * Return  0 if the extent buffer doesn't need to be submitted.
- *           (E.g. the extent buffer is not dirty)
- * Return >0 is the extent buffer is submitted to bio.
- * Return <0 if something went wrong, no page is locked.
+ * Return %false if the extent buffer doesn't need to be submitted (e.g. the
+ * extent buffer is not dirty)
+ * Return %true is the extent buffer is submitted to bio.
  */
-static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb,
-			  struct btrfs_bio_ctrl *bio_ctrl)
+static bool lock_extent_buffer_for_io(struct extent_buffer *eb,
+				      struct btrfs_bio_ctrl *bio_ctrl)
 {
 	struct btrfs_fs_info *fs_info = eb->fs_info;
 	int i, num_pages;
 	int flush = 0;
-	int ret = 0;
+	bool ret = false;
 
 	if (!btrfs_try_tree_write_lock(eb)) {
 		submit_write_bio(bio_ctrl, 0);
@@ -1650,7 +1649,7 @@  static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb
 	if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) {
 		btrfs_tree_unlock(eb);
 		if (bio_ctrl->wbc->sync_mode != WB_SYNC_ALL)
-			return 0;
+			return false;
 		if (!flush) {
 			submit_write_bio(bio_ctrl, 0);
 			flush = 1;
@@ -1677,7 +1676,7 @@  static noinline_for_stack int lock_extent_buffer_for_io(struct extent_buffer *eb
 		percpu_counter_add_batch(&fs_info->dirty_metadata_bytes,
 					 -eb->len,
 					 fs_info->dirty_metadata_batch);
-		ret = 1;
+		ret = true;
 	} else {
 		spin_unlock(&eb->refs_lock);
 	}
@@ -2011,7 +2010,6 @@  static int submit_eb_subpage(struct page *page, struct btrfs_bio_ctrl *bio_ctrl)
 	u64 page_start = page_offset(page);
 	int bit_start = 0;
 	int sectors_per_node = fs_info->nodesize >> fs_info->sectorsize_bits;
-	int ret;
 
 	/* Lock and write each dirty extent buffers in the range */
 	while (bit_start < fs_info->subpage_info->bitmap_nr_bits) {
@@ -2057,25 +2055,13 @@  static int submit_eb_subpage(struct page *page, struct btrfs_bio_ctrl *bio_ctrl)
 		if (!eb)
 			continue;
 
-		ret = lock_extent_buffer_for_io(eb, bio_ctrl);
-		if (ret == 0) {
-			free_extent_buffer(eb);
-			continue;
+		if (lock_extent_buffer_for_io(eb, bio_ctrl)) {
+			write_one_subpage_eb(eb, bio_ctrl);
+			submitted++;
 		}
-		if (ret < 0) {
-			free_extent_buffer(eb);
-			goto cleanup;
-		}
-		write_one_subpage_eb(eb, bio_ctrl);
 		free_extent_buffer(eb);
-		submitted++;
 	}
 	return submitted;
-
-cleanup:
-	/* We hit error, end bio for the submitted extent buffers */
-	submit_write_bio(bio_ctrl, ret);
-	return ret;
 }
 
 /*
@@ -2154,8 +2140,7 @@  static int submit_eb_page(struct page *page, struct btrfs_bio_ctrl *bio_ctrl,
 
 	*eb_context = eb;
 
-	ret = lock_extent_buffer_for_io(eb, bio_ctrl);
-	if (ret <= 0) {
+	if (!lock_extent_buffer_for_io(eb, bio_ctrl)) {
 		btrfs_revert_meta_write_pointer(cache, eb);
 		if (cache)
 			btrfs_put_block_group(cache);