btrfs: move the compress_type check out of btrfs_bio_add_page

The compress_type can only change on a per-extent basis.  So instead of
checking it for every page in btrfs_bio_add_page, do the check once in
btrfs_do_readpage, which is the only caller of btrfs_bio_add_page and
submit_extent_page that deals with compressed extents.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 468046ecca7c1e6f478e941b196e32d4f796e384..acdbefc8871c5e88008aec0f2c6766449060aa67 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -875,7 +875,6 @@ int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array)
  *                  a contiguous page to the previous one
  * @size:          portion of page that we want to write
  * @pg_offset:     starting offset in the page
- * @compress_type:  compression type of the current bio to see if we can merge them
  *
  * Attempt to add a page to bio considering stripe alignment etc.
  *
@@ -886,8 +885,7 @@ int btrfs_alloc_page_array(unsigned int nr_pages, struct page **page_array)
 static int btrfs_bio_add_page(struct btrfs_bio_ctrl *bio_ctrl,
                              struct page *page,
                              u64 disk_bytenr, unsigned int size,
-                             unsigned int pg_offset,
-                             enum btrfs_compression_type compress_type)
+                             unsigned int pg_offset)
 {
        struct bio *bio = bio_ctrl->bio;
        u32 bio_size = bio->bi_iter.bi_size;
@@ -898,9 +896,6 @@ static int btrfs_bio_add_page(struct btrfs_bio_ctrl *bio_ctrl,
        ASSERT(bio);
        /* The limit should be calculated when bio_ctrl->bio is allocated */
        ASSERT(bio_ctrl->len_to_oe_boundary);
-       if (bio_ctrl->compress_type != compress_type)
-               return 0;
-
 
        if (bio->bi_iter.bi_size == 0) {
                /* We can always add a page into an empty bio. */
@@ -1049,12 +1044,11 @@ static int submit_extent_page(struct btrfs_bio_ctrl *bio_ctrl,
                 */
                if (compress_type != BTRFS_COMPRESS_NONE)
                        added = btrfs_bio_add_page(bio_ctrl, page, disk_bytenr,
-                                       size - offset, pg_offset + offset,
-                                       compress_type);
+                                       size - offset, pg_offset + offset);
                else
                        added = btrfs_bio_add_page(bio_ctrl, page,
                                        disk_bytenr + offset, size - offset,
-                                       pg_offset + offset, compress_type);
+                                       pg_offset + offset);
 
                /* Metadata page range should never be split */
                if (!is_data_inode(&inode->vfs_inode))
@@ -1320,6 +1314,9 @@ static int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
                        continue;
                }
 
+               if (bio_ctrl->compress_type != this_bio_flag)
+                       submit_one_bio(bio_ctrl);
+
                if (force_bio_submit)
                        submit_one_bio(bio_ctrl);
                ret = submit_extent_page(bio_ctrl, disk_bytenr, page, iosize,