Btrfs: Bring back mount -o ssd optimizations

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

fs/btrfs/ctree.h

@@ -1405,6 +1405,9 @@ int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
 			struct btrfs_root *root, struct btrfs_path *path,
 			u64 isize);
 /* inode.c */
+int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
+			 size_t size, struct bio *bio);
+
 static inline void dec_i_blocks(struct inode *inode, u64 dec)
 {
 	dec = dec >> 9;

fs/btrfs/disk-io.c

@@ -1103,4 +1103,6 @@ int btrfs_read_buffer(struct extent_buffer *buf)
 static struct extent_io_ops btree_extent_io_ops = {
 	.writepage_io_hook = btree_writepage_io_hook,
 	.submit_bio_hook = btree_submit_bio_hook,
+	/* note we're sharing with inode.c for the merge bio hook */
+	.merge_bio_hook = btrfs_merge_bio_hook,
 };

fs/btrfs/extent-tree.c

@@ -1473,13 +1473,31 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
 	struct btrfs_root * root = orig_root->fs_info->extent_root;
 	struct btrfs_fs_info *info = root->fs_info;
 	u64 total_needed = num_bytes;
+	u64 *last_ptr = NULL;
 	struct btrfs_block_group_cache *block_group;
 	int full_scan = 0;
 	int wrapped = 0;
+	int empty_cluster = 2 * 1024 * 1024;
 
 	WARN_ON(num_bytes < root->sectorsize);
 	btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
 
+	if (data & BTRFS_BLOCK_GROUP_METADATA) {
+		last_ptr = &root->fs_info->last_alloc;
+	}
+
+	if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) {
+		last_ptr = &root->fs_info->last_data_alloc;
+	}
+
+	if (last_ptr) {
+		if (*last_ptr)
+			hint_byte = *last_ptr;
+		else {
+			empty_size += empty_cluster;
+		}
+	}
+
 	if (search_end == (u64)-1)
 		search_end = btrfs_super_total_bytes(&info->super_copy);
 
@@ -1489,11 +1507,14 @@ static int noinline find_free_extent(struct btrfs_trans_handle *trans,
 			hint_byte = search_start;
 		block_group = btrfs_find_block_group(root, block_group,
 						     hint_byte, data, 1);
+		if (last_ptr && *last_ptr == 0 && block_group)
+			hint_byte = block_group->key.objectid;
 	} else {
 		block_group = btrfs_find_block_group(root,
 						     trans->block_group,
 						     search_start, data, 1);
 	}
+	search_start = max(search_start, hint_byte);
 
 	total_needed += empty_size;
 
@@ -1506,9 +1527,36 @@ check_failed:
 	}
 	ret = find_search_start(root, &block_group, &search_start,
 				total_needed, data);
+	if (ret == -ENOSPC && last_ptr && *last_ptr) {
+		*last_ptr = 0;
+		block_group = btrfs_lookup_block_group(info,
+						       orig_search_start);
+		search_start = orig_search_start;
+		ret = find_search_start(root, &block_group, &search_start,
+					total_needed, data);
+	}
+	if (ret == -ENOSPC)
+		goto enospc;
 	if (ret)
 		goto error;
 
+	if (last_ptr && *last_ptr && search_start != *last_ptr) {
+		*last_ptr = 0;
+		if (!empty_size) {
+			empty_size += empty_cluster;
+			total_needed += empty_size;
+		}
+		block_group = btrfs_lookup_block_group(info,
+						       orig_search_start);
+		search_start = orig_search_start;
+		ret = find_search_start(root, &block_group,
+					&search_start, total_needed, data);
+		if (ret == -ENOSPC)
+			goto enospc;
+		if (ret)
+			goto error;
+	}
+
 	search_start = stripe_align(root, search_start);
 	ins->objectid = search_start;
 	ins->offset = num_bytes;
@@ -1547,6 +1595,13 @@ check_failed:
 			trans->block_group = block_group;
 	}
 	ins->offset = num_bytes;
+	if (last_ptr) {
+		*last_ptr = ins->objectid + ins->offset;
+		if (*last_ptr ==
+		    btrfs_super_total_bytes(&root->fs_info->super_copy)) {
+			*last_ptr = 0;
+		}
+	}
 	return 0;
 
 new_group:
@@ -1612,12 +1667,12 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
 	if (root->ref_cows) {
 		if (data != BTRFS_BLOCK_GROUP_METADATA) {
 			ret = do_chunk_alloc(trans, root->fs_info->extent_root,
-					     num_bytes,
+					     2 * 1024 * 1024,
 					     BTRFS_BLOCK_GROUP_METADATA);
 			BUG_ON(ret);
 		}
 		ret = do_chunk_alloc(trans, root->fs_info->extent_root,
-				     num_bytes, data);
+				     num_bytes + 2 * 1024 * 1024, data);
 		BUG_ON(ret);
 	}
 

fs/btrfs/extent_io.c

@@ -1730,6 +1730,8 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
 	if (bio_ret && *bio_ret) {
 		bio = *bio_ret;
 		if (bio->bi_sector + (bio->bi_size >> 9) != sector ||
+		    (tree->ops && tree->ops->merge_bio_hook &&
+		     tree->ops->merge_bio_hook(page, offset, size, bio)) ||
 		    bio_add_page(bio, page, size, offset) < size) {
 			ret = submit_one_bio(rw, bio);
 			bio = NULL;

fs/btrfs/extent_io.h

@@ -29,6 +29,8 @@ struct extent_io_ops {
 	int (*fill_delalloc)(struct inode *inode, u64 start, u64 end);
 	int (*writepage_io_hook)(struct page *page, u64 start, u64 end);
 	int (*submit_bio_hook)(struct inode *inode, int rw, struct bio *bio);
+	int (*merge_bio_hook)(struct page *page, unsigned long offset,
+			      size_t size, struct bio *bio);
 	int (*readpage_io_hook)(struct page *page, u64 start, u64 end);
 	int (*readpage_end_io_hook)(struct page *page, u64 start, u64 end,
 				    struct extent_state *state);

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,

fs/btrfs/volumes.c

@@ -578,6 +578,11 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio)
 	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) {
+		printk("mapping failed logical %Lu bio len %Lu physical %Lu "
+		       "len %Lu\n", logical, length, physical, map_length);
+		BUG();
+	}
 	BUG_ON(map_length < length);
 	bio->bi_sector = physical >> 9;
 	bio->bi_bdev = dev->bdev;

fs/btrfs/volumes.h

@@ -64,4 +64,7 @@ void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio);
 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf);
+int btrfs_map_block(struct btrfs_mapping_tree *map_tree,
+		    u64 logical, u64 *phys, u64 *length,
+		    struct btrfs_device **dev);
 #endif