btrfs: Return number of compressed extents directly in compress_file_…

…range

compress_file_range returns a void, yet uses a function parameter as a
return value. Make that more idiomatic by simply returning the number
of compressed extents directly. Also track such extents in more aptly
named variables. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -462,8 +462,7 @@ static inline void inode_should_defrag(struct btrfs_inode *inode,
  * are written in the same order that the flusher thread sent them
  * down.
  */
-static noinline void compress_file_range(struct async_chunk *async_chunk,
- int *num_added)
+static noinline int compress_file_range(struct async_chunk *async_chunk)
 {
  struct inode *inode = async_chunk->inode;
  struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
@@ -479,6 +478,7 @@ static noinline void compress_file_range(struct async_chunk *async_chunk,
  int i;
  int will_compress;
  int compress_type = fs_info->compress_type;
+ int compressed_extents = 0;
  int redirty = 0;
 
  inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
@@ -641,7 +641,7 @@ static noinline void compress_file_range(struct async_chunk *async_chunk,
  */
  total_in = ALIGN(total_in, PAGE_SIZE);
  if (total_compressed + blocksize <= total_in) {
- *num_added += 1;
+ compressed_extents++;
 
  /*
  * The async work queues will take care of doing actual
@@ -658,7 +658,7 @@ static noinline void compress_file_range(struct async_chunk *async_chunk,
  cond_resched();
  goto again;
  }
- return;
+ return compressed_extents;
  }
  }
  if (pages) {
@@ -697,16 +697,18 @@ static noinline void compress_file_range(struct async_chunk *async_chunk,
  extent_range_redirty_for_io(inode, start, end);
  add_async_extent(async_chunk, start, end - start + 1, 0, NULL, 0,
  BTRFS_COMPRESS_NONE);
- *num_added += 1;
+ compressed_extents++;
 
- return;
+ return compressed_extents;
 
 free_pages_out:
  for (i = 0; i < nr_pages; i++) {
  WARN_ON(pages[i]->mapping);
  put_page(pages[i]);
  }
  kfree(pages);
+
+ return 0;
 }
 
 static void free_async_extent_pages(struct async_extent *async_extent)
@@ -1144,12 +1146,12 @@ static noinline int cow_file_range(struct inode *inode,
 static noinline void async_cow_start(struct btrfs_work *work)
 {
  struct async_chunk *async_chunk;
- int num_added = 0;
+ int compressed_extents;
 
  async_chunk = container_of(work, struct async_chunk, work);
 
- compress_file_range(async_chunk, &num_added);
- if (num_added == 0) {
+ compressed_extents = compress_file_range(async_chunk);
+ if (compressed_extents == 0) {
  btrfs_add_delayed_iput(async_chunk->inode);
  async_chunk->inode = NULL;
  }