Re: [PATCH 02/12] xfs: set IOMAP_F_NEW more carefully

2019-10-15 Thread Dave Chinner
On Tue, Oct 15, 2019 at 05:43:35PM +0200, Christoph Hellwig wrote: > Don't set IOMAP_F_NEW if we COW over and existing allocated range, as > these aren't strictly new allocations. This is required to be able to > use IOMAP_F_NEW to zero newly allocated blocks, which is required for > the iomap cod

Re: [PATCH 02/12] xfs: set IOMAP_F_NEW more carefully

2019-10-15 Thread Darrick J. Wong
On Tue, Oct 15, 2019 at 05:43:35PM +0200, Christoph Hellwig wrote: > Don't set IOMAP_F_NEW if we COW over and existing allocated range, as "..over an existing..." > these aren't strictly new allocations. This is required to be able to > use IOMAP_F_NEW to zero newly allocated blocks, which is re

[PATCH 02/12] xfs: set IOMAP_F_NEW more carefully

2019-10-15 Thread Christoph Hellwig
Don't set IOMAP_F_NEW if we COW over and existing allocated range, as these aren't strictly new allocations. This is required to be able to use IOMAP_F_NEW to zero newly allocated blocks, which is required for the iomap code to fully support file systems that don't do delayed allocations or use un