Commit 9f9b8e8d authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: extent-tree: Detect bytes_may_use underflow earlier 



Although we have space_info::bytes_may_use underflow detection in
btrfs_free_reserved_data_space_noquota(), we have more callers who are
subtracting number from space_info::bytes_may_use.

So instead of doing underflow detection for every caller, introduce a
new wrapper update_bytes_may_use() to replace open coded bytes_may_use
modifiers.

This also introduce a macro to declare more wrappers, but currently
space_info::bytes_may_use is the mostly interesting one.

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarLu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 85dd506c

fs/btrfs/extent-tree.c

+30 −16
Original line number Diff line number Diff line
@@ -51,6 +51,23 @@ enum { 
	CHUNK_ALLOC_FORCE = 2,

};



/*

 * Declare a helper function to detect underflow of various space info members

 */

#define DECLARE_SPACE_INFO_UPDATE(name)					\

static inline void update_##name(struct btrfs_space_info *sinfo,	\

				 s64 bytes)				\

{									\

	if (bytes < 0 && sinfo->name < -bytes) {			\

		WARN_ON(1);						\

		sinfo->name = 0;					\

		return;							\

	}								\

	sinfo->name += bytes;						\

}



DECLARE_SPACE_INFO_UPDATE(bytes_may_use);



static int __btrfs_free_extent(struct btrfs_trans_handle *trans,

			       struct btrfs_delayed_ref_node *node, u64 parent,

			       u64 root_objectid, u64 owner_objectid,
@@ -4256,7 +4273,7 @@ commit_trans: 
					      data_sinfo->flags, bytes, 1);

		return -ENOSPC;

	}

	data_sinfo->bytes_may_use += bytes;

	update_bytes_may_use(data_sinfo, bytes);

	trace_btrfs_space_reservation(fs_info, "space_info",

				      data_sinfo->flags, bytes, 1);

	spin_unlock(&data_sinfo->lock);
@@ -4309,10 +4326,7 @@ void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start, 


	data_sinfo = fs_info->data_sinfo;

	spin_lock(&data_sinfo->lock);

	if (WARN_ON(data_sinfo->bytes_may_use < len))

		data_sinfo->bytes_may_use = 0;

	else

		data_sinfo->bytes_may_use -= len;

	update_bytes_may_use(data_sinfo, -len);

	trace_btrfs_space_reservation(fs_info, "space_info",

				      data_sinfo->flags, len, 0);

	spin_unlock(&data_sinfo->lock);
@@ -5108,7 +5122,7 @@ static int wait_reserve_ticket(struct btrfs_fs_info *fs_info, 
		list_del_init(&ticket->list);

	if (ticket->bytes && ticket->bytes < orig_bytes) {

		u64 num_bytes = orig_bytes - ticket->bytes;

		space_info->bytes_may_use -= num_bytes;

		update_bytes_may_use(space_info, -num_bytes);

		trace_btrfs_space_reservation(fs_info, "space_info",

					      space_info->flags, num_bytes, 0);

	}
@@ -5154,13 +5168,13 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, 
	 * If not things get more complicated.

	 */

	if (used + orig_bytes <= space_info->total_bytes) {

		space_info->bytes_may_use += orig_bytes;

		update_bytes_may_use(space_info, orig_bytes);

		trace_btrfs_space_reservation(fs_info, "space_info",

					      space_info->flags, orig_bytes, 1);

		ret = 0;

	} else if (can_overcommit(fs_info, space_info, orig_bytes, flush,

				  system_chunk)) {

		space_info->bytes_may_use += orig_bytes;

		update_bytes_may_use(space_info, orig_bytes);

		trace_btrfs_space_reservation(fs_info, "space_info",

					      space_info->flags, orig_bytes, 1);

		ret = 0;
@@ -5223,7 +5237,7 @@ static int __reserve_metadata_bytes(struct btrfs_fs_info *fs_info, 
	if (ticket.bytes) {

		if (ticket.bytes < orig_bytes) {

			u64 num_bytes = orig_bytes - ticket.bytes;

			space_info->bytes_may_use -= num_bytes;

			update_bytes_may_use(space_info, -num_bytes);

			trace_btrfs_space_reservation(fs_info, "space_info",

						      space_info->flags,

						      num_bytes, 0);
@@ -5407,7 +5421,7 @@ again: 
		flush = BTRFS_RESERVE_FLUSH_ALL;

		goto again;

	}

	space_info->bytes_may_use -= num_bytes;

	update_bytes_may_use(space_info, -num_bytes);

	trace_btrfs_space_reservation(fs_info, "space_info",

				      space_info->flags, num_bytes, 0);

	spin_unlock(&space_info->lock);
@@ -5435,7 +5449,7 @@ again: 
						      ticket->bytes, 1);

			list_del_init(&ticket->list);

			num_bytes -= ticket->bytes;

			space_info->bytes_may_use += ticket->bytes;

			update_bytes_may_use(space_info, ticket->bytes);

			ticket->bytes = 0;

			space_info->tickets_id++;

			wake_up(&ticket->wait);
@@ -5443,7 +5457,7 @@ again: 
			trace_btrfs_space_reservation(fs_info, "space_info",

						      space_info->flags,

						      num_bytes, 1);

			space_info->bytes_may_use += num_bytes;

			update_bytes_may_use(space_info, num_bytes);

			ticket->bytes -= num_bytes;

			num_bytes = 0;

		}
@@ -5750,14 +5764,14 @@ static void update_global_block_rsv(struct btrfs_fs_info *fs_info) 
			num_bytes = min(num_bytes,

					block_rsv->size - block_rsv->reserved);

			block_rsv->reserved += num_bytes;

			sinfo->bytes_may_use += num_bytes;

			update_bytes_may_use(sinfo, num_bytes);

			trace_btrfs_space_reservation(fs_info, "space_info",

						      sinfo->flags, num_bytes,

						      1);

		}

	} else if (block_rsv->reserved > block_rsv->size) {

		num_bytes = block_rsv->reserved - block_rsv->size;

		sinfo->bytes_may_use -= num_bytes;

		update_bytes_may_use(sinfo, -num_bytes);

		trace_btrfs_space_reservation(fs_info, "space_info",

				      sinfo->flags, num_bytes, 0);

		block_rsv->reserved = block_rsv->size;
@@ -6431,7 +6445,7 @@ static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache, 
	} else {

		cache->reserved += num_bytes;

		space_info->bytes_reserved += num_bytes;

		space_info->bytes_may_use -= ram_bytes;

		update_bytes_may_use(space_info, -ram_bytes);

		if (delalloc)

			cache->delalloc_bytes += num_bytes;

	}
@@ -6608,7 +6622,7 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info, 
				to_add = min(len, global_rsv->size -

					     global_rsv->reserved);

				global_rsv->reserved += to_add;

				space_info->bytes_may_use += to_add;

				update_bytes_may_use(space_info, to_add);

				if (global_rsv->reserved >= global_rsv->size)

					global_rsv->full = 1;

				trace_btrfs_space_reservation(fs_info,

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