Btrfs: Bring back mount -o ssd optimizations

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 109576b57f69..5140d6801846 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -296,6 +296,34 @@ int btrfs_clear_bit_hook(struct inode *inode, u64 start, u64 end,
         return 0;
 }
 
+int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
+                         size_t size, struct bio *bio)
+{
+        struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
+        struct btrfs_mapping_tree *map_tree;
+        struct btrfs_device *dev;
+        u64 logical = bio->bi_sector << 9;
+        u64 physical;
+        u64 length = 0;
+        u64 map_length;
+        struct bio_vec *bvec;
+        int i;
+        int ret;
+
+        bio_for_each_segment(bvec, bio, i) {
+                length += bvec->bv_len;
+        }
+        map_tree = &root->fs_info->mapping_tree;
+        map_length = length;
+        ret = btrfs_map_block(map_tree, logical, &physical, &map_length, &dev);
+        if (map_length < length + size) {
+                printk("merge bio hook logical %Lu bio len %Lu physical %Lu "
+                       "len %Lu\n", logical, length, physical, map_length);
+                return 1;
+        }
+        return 0;
+}
+
 int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio)
 {
         struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -3033,6 +3061,7 @@ static struct file_operations btrfs_dir_file_operations = {
 static struct extent_io_ops btrfs_extent_io_ops = {
         .fill_delalloc = run_delalloc_range,
         .submit_bio_hook = btrfs_submit_bio_hook,
+        .merge_bio_hook = btrfs_merge_bio_hook,
         .readpage_io_hook = btrfs_readpage_io_hook,
         .readpage_end_io_hook = btrfs_readpage_end_io_hook,
         .set_bit_hook = btrfs_set_bit_hook,