On Thu, May 07, 2020 at 10:14:05PM -0500, Goldwyn Rodrigues wrote:
> geenric/475 fails because there are reservations left in the inode's
> block reservations system which are not cleared out. So the system
> triggers WARN_ON() while performing destroy_inode.
>
> The problem is similar to described in:
> 50745b0a7f46 ("Btrfs: Direct I/O: Fix space accounting")
>
> To test the theory, I framed an ugly patch of using an extra field
> in current-> task_struct to store a number which carries the reservation
> currently remaining like the patch does and it works. So what we need is
> a way to carry reservation information from btrfs_direct_write() to
> iomap's direct ops ->submit_io() where the reservations are consumed.
>
> We cannot use a similar solution of using current->journal_info
> because fdatawrite sequence in iomap_dio_rw() uses
> current->journal_info.
>
> We cannot perform data reservations and release in iomap_begin() and
> iomap_end() for performance and accounting issues.
So just drop "btrfs: Use ->iomap_end() instead of btrfs_dio_data"
from the series and be done with it?
