From 63e242afa4661632786a2129cf297a135a6995ba Mon Sep 17 00:00:00 2001 From: Andrey Albershteyn Date: Wed, 20 May 2026 14:37:05 +0200 Subject: iomap: introduce IOMAP_F_FSVERITY and teach writeback to handle fsverity This flag indicates that I/O is for fsverity metadata. In the write path skip i_size check and i_size updates as metadata is past EOF. In writeback don't update i_size and continue writeback if even folio is beyond EOF. In read path don't zero fsverity folios, again they are past EOF. The iomap_block_needs_zeroing() is also called from write path. For folios of larger order we don't want to zero out pages in the folio as these could contain other merkle tree blocks. For fsverity, filesystem will request to read PAGE_SIZE memory regions. For data folios, iomap will zero the rest of the folio for anything which is beyond EOF. We don't want this for fsverity folios. Christian Brauner says: Changed IOMAP_F_FSVERITY from (1U << 10) to (1U << 11) to avoid colliding with IOMAP_F_ZERO_TAIL, which already uses (1U << 10). Signed-off-by: Andrey Albershteyn Link: https://patch.msgid.link/20260520123722.405752-8-aalbersh@kernel.org Reviewed-by: "Darrick J. Wong" Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Amutable) --- include/linux/iomap.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux') diff --git a/include/linux/iomap.h b/include/linux/iomap.h index cea6bbc97b6e..5b2b40e81b61 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -91,6 +91,14 @@ struct vm_fault; #endif /* CONFIG_BLK_DEV_INTEGRITY */ #define IOMAP_F_ZERO_TAIL (1U << 10) +/* + * Indicates reads and writes of fsverity metadata. + * + * Fsverity metadata is stored after the regular file data and thus beyond + * i_size. + */ +#define IOMAP_F_FSVERITY (1U << 11) + /* * Flag reserved for file system specific usage */ -- cgit v1.2.3