On Wed, Sep 25, 2024 at 11:01:46PM +1000, Dave Chinner wrote: > On Wed, Sep 25, 2024 at 07:27:38AM -0400, Sasha Levin wrote: > > From: Pankaj Raghav <p.raghav@xxxxxxxxxxx> > > > > [ Upstream commit 10553a91652d995274da63fc317470f703765081 ] > > > > 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, 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. > > Please drop this. It is for support of new functionality that was > just merged and has no relevance to older kernels. It is not a bug > fix. > I did not have any fixes by tag for this reason. So please drop this commit from the queue. > And .... > > > + > > + set_memory_ro((unsigned long)page_address(zero_page), > > + 1U << IOMAP_ZERO_PAGE_ORDER); > > .... this will cause stable kernel regressions. > > It was removed later in the merge because it is unnecessary and > causes boot failures on (at least) some Power architectures. > > -Dave. > -- > Dave Chinner > david@xxxxxxxxxxxxx -- Pankaj Raghav
