Commit 8b53779e authored by Ioannis Angelakopoulos's avatar Ioannis Angelakopoulos Committed by David Sterba
Browse files

btrfs: add lockdep annotations for pending_ordered wait event 



In contrast to the num_writers and num_extwriters wait events, the
condition for the pending ordered wait event is signaled in a different
context from the wait event itself. The condition signaling occurs in
btrfs_remove_ordered_extent() in fs/btrfs/ordered-data.c while the wait
event is implemented in btrfs_commit_transaction() in
fs/btrfs/transaction.c

Thus the thread signaling the condition has to acquire the lockdep map
as a reader at the start of btrfs_remove_ordered_extent() and release it
after it has signaled the condition. In this case some dependencies
might be left out due to the placement of the annotation, but it is
better than no annotation at all.

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarIoannis Angelakopoulos <iangelak@fb.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 3e738c53

fs/btrfs/ctree.h

+1 −0
Original line number Diff line number Diff line
@@ -1099,6 +1099,7 @@ struct btrfs_fs_info { 
	struct lockdep_map btrfs_trans_num_writers_map;

	struct lockdep_map btrfs_trans_num_extwriters_map;

	struct lockdep_map btrfs_state_change_map[4];

	struct lockdep_map btrfs_trans_pending_ordered_map;



#ifdef CONFIG_BTRFS_FS_REF_VERIFY

	spinlock_t ref_verify_lock;

fs/btrfs/disk-io.c

+1 −0
Original line number Diff line number Diff line
@@ -2992,6 +2992,7 @@ void btrfs_init_fs_info(struct btrfs_fs_info *fs_info) 


	btrfs_lockdep_init_map(fs_info, btrfs_trans_num_writers);

	btrfs_lockdep_init_map(fs_info, btrfs_trans_num_extwriters);

	btrfs_lockdep_init_map(fs_info, btrfs_trans_pending_ordered);

	btrfs_state_lockdep_init_map(fs_info, btrfs_trans_commit_start,

				     BTRFS_LOCKDEP_TRANS_COMMIT_START);

	btrfs_state_lockdep_init_map(fs_info, btrfs_trans_unblocked,

fs/btrfs/ordered-data.c

+3 −0
Original line number Diff line number Diff line
@@ -525,6 +525,7 @@ void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode, 
	struct rb_node *node;

	bool pending;



	btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);

	/* This is paired with btrfs_add_ordered_extent. */

	spin_lock(&btrfs_inode->lock);

	btrfs_mod_outstanding_extents(btrfs_inode, -1);
@@ -580,6 +581,8 @@ void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode, 
		}

	}



	btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);



	spin_lock(&root->ordered_extent_lock);

	list_del_init(&entry->root_extent_list);

	root->nr_ordered_extents--;

fs/btrfs/transaction.c

+1 −0
Original line number Diff line number Diff line
@@ -2310,6 +2310,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) 
	 * transaction. Otherwise if this transaction commits before the ordered

	 * extents complete we lose logged data after a power failure.

	 */

	btrfs_might_wait_for_event(fs_info, btrfs_trans_pending_ordered);

	wait_event(cur_trans->pending_wait,

		   atomic_read(&cur_trans->pending_ordered) == 0);