btrfs: add and use helper to assert an inode range is clean

We have four different scenarios where we don't expect to find ordered
extents after locking a file range:

1) During plain fallocate;
2) During hole punching;
3) During zero range;
4) During reflinks (both cloning and deduplication).

This is because in all these cases we follow the pattern:

1) Lock the inode's VFS lock in exclusive mode;

2) Lock the inode's i_mmap_lock in exclusive node, to serialize with
   mmap writes;

3) Flush delalloc in a file range and wait for all ordered extents
   to complete - both done through btrfs_wait_ordered_range();

4) Lock the file range in the inode's io_tree.

So add a helper that asserts that we don't have ordered extents for a
given range. Make the four scenarios listed above use this helper after
locking the respective file range.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index fd90e25382b2..bd329316945f 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2608,6 +2608,8 @@ static void btrfs_punch_hole_lock_range(struct inode *inode,
 		unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
 				     lockend, cached_state);
 	}
+
+	btrfs_assert_inode_range_clean(BTRFS_I(inode), lockstart, lockend);
 }
 
 static int btrfs_insert_replace_extent(struct btrfs_trans_handle *trans,
@@ -3479,6 +3481,8 @@ static long btrfs_fallocate(struct file *file, int mode,
 	lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
 			 &cached_state);
 
+	btrfs_assert_inode_range_clean(BTRFS_I(inode), alloc_start, locked_end);
+
 	/* First, check if we exceed the qgroup limit */
 	INIT_LIST_HEAD(&reserve_list);
 	while (cur_offset < alloc_end) {