Re: [PATCH 1/2] btrfs: Return number of compressed extents directly in compress_file_range

[Anand Jain]

On 2/7/19 12:50 AM, Nikolay Borisov wrote:

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 <nbori...@suse.com>

Looks good.

Reviewed-by: Anand Jain <anand.j...@oracle.com>

---
  fs/btrfs/inode.c | 20 +++++++++++---------
  1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4e183c2d3555..3b0bf5ea9eb6 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -440,8 +440,7 @@ 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);
@@ -457,6 +456,7 @@ 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,

@@ -619,7 +619,7 @@ 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 += 1;

/*

                         * The async work queues will take care of doing actual
@@ -636,7 +636,7 @@ static noinline void compress_file_range(struct async_chunk 
*async_chunk,
                                cond_resched();
                                goto again;
                        }
-                       return;
+                       return compressed_extents;
                }
        }
        if (pages) {
@@ -675,9 +675,9 @@ 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 += 1;

- return;

+       return compressed_extents;

free_pages_out:

        for (i = 0; i < nr_pages; i++) {
@@ -685,6 +685,8 @@ static noinline void compress_file_range(struct async_chunk 
*async_chunk,
                put_page(pages[i]);
        }
        kfree(pages);
+
+       return 0;
  }

static void free_async_extent_pages(struct async_extent *async_extent)

@@ -1122,12 +1124,12 @@ 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 = 0;

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;
        }