On Thu, Oct 26, 2023 at 04:08:32PM +0200, Pankaj Raghav wrote:
> From: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
>
> iomap_dio_zero() will pad a fs block with zeroes if the direct IO size
> < fs block size. iomap_dio_zero() has an implicit assumption that fs block
> size < page_size. This is true for most filesystems at the moment.
>
> If the block size > page size (Large block sizes)[1], this will send the
> contents of the page next to zero page(as len > PAGE_SIZE) to the
> underlying block device, causing FS corruption.
>
> iomap is a generic infrastructure and it should not make any assumptions
> about the fs block size and the page size of the system.
>
> Fixes: db074436f421 ("iomap: move the direct IO code into a separate file")
I forgot to mention - this fixes tag is completely bogus. That's
just a commit that moves the code from one file to another and
there's no actual functional change at all.
Further, this isn't a change that "fixes" a bug or regression - it
is a change to support new functionality that doesnt' yet exist
upstream, and so there is no bug in the existing kernels for it to
fix....
-Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
