[dm-devel] [PATCH RFC 4/8] fs: Introduce FALLOC_FL_PROVISION

[Christoph Hellwig]

On Tue, Sep 20, 2022 at 10:54:32PM -0700, Sarthak Kukreti wrote:
> [ mmc0blkp1 | ext4(1) | sparse file | loop | dm-thinp | dm-thin | ext4(2) ]
> 
> would be predicated on the guarantees of fallocate() per allocation
> layer; if ext4(1) was replaced by a filesystem that did not support
> fallocate(), then there would be no guarantee that a write to a file
> on ext4(2) succeeds.

a write or any unlimited number of writes?