btrfs: Refactor btrfs_merge_bio_hook

This function really checks whether adding more data to the bio will
straddle a stripe/chunk. So first let's give it a more appropraite name
- btrfs_bio_fits_in_stripe. Secondly, the offset parameter was never
used to just remove it. Thirdly, pages are submitted to either btree or
data inodes so it's guaranteed that tree->ops is set so replace the
check with an ASSERT. Finally, document the parameters of the function.
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>

1 files changed, 4 insertions, 3 deletions

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 34d50bc5c10d..dba59ae914b8 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -332,7 +332,8 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
                 page = compressed_pages[pg_index];
                 page->mapping = inode->i_mapping;
                 if (bio->bi_iter.bi_size)
-                        submit = btrfs_merge_bio_hook(page, 0, PAGE_SIZE, bio, 0);
+                        submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE, bio,
+                                                          0);
 
                 page->mapping = NULL;
                 if (submit || bio_add_page(bio, page, PAGE_SIZE, 0) <
@@ -610,8 +611,8 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
                 page->index = em_start >> PAGE_SHIFT;
 
                 if (comp_bio->bi_iter.bi_size)
-                        submit = btrfs_merge_bio_hook(page, 0, PAGE_SIZE,
-                                        comp_bio, 0);
+                        submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE,
+                                                          comp_bio, 0);
 
                 page->mapping = NULL;
                 if (submit || bio_add_page(comp_bio, page, PAGE_SIZE, 0) <