Merge patch series "fs: refactor write_begin/write_end and add ext4 IOCB_DONTCACHE support"

陈涛涛 Taotao Chen <chentaotao@didiglobal.com> says:

This patch series refactors the address_space_operations write_begin()
and write_end() callbacks to take const struct kiocb * as their first
argument, allowing IOCB flags such as IOCB_DONTCACHE to propagate to the
filesystem's buffered I/O path.

Ext4 is updated to implement handling of the IOCB_DONTCACHE flag and
advertises support via the FOP_DONTCACHE file operation flag.

Additionally, the i915 driver's shmem write paths are updated to bypass
the legacy write_begin/write_end interface in favor of directly
calling write_iter() with a constructed synchronous kiocb. Another i915
change replaces a manual write loop with kernel_write() during GEM shmem
object creation.

Tested with ext4 and i915 GEM workloads.

* patches from https://lore.kernel.org/20250716093559.217344-1-chentaotao@didiglobal.com:
  ext4: support uncached buffered I/O
  mm/pagemap: add write_begin_get_folio() helper function
  fs: change write_begin/write_end interface to take struct kiocb *
  drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter
  drm/i915: Use kernel_write() in shmem object create

Link: https://lore.kernel.org/20250716093559.217344-1-chentaotao@didiglobal.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 178eb90e9cf3..b16b88bfbc3e 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -263,11 +263,11 @@ int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
 int __block_write_begin(struct folio *folio, loff_t pos, unsigned len,
 		get_block_t *get_block);
 int block_write_end(loff_t pos, unsigned len, unsigned copied, struct folio *);
-int generic_write_end(struct file *, struct address_space *,
+int generic_write_end(const struct kiocb *, struct address_space *,
 				loff_t, unsigned len, unsigned copied,
 				struct folio *, void *);
 void folio_zero_new_buffers(struct folio *folio, size_t from, size_t to);
-int cont_write_begin(struct file *, struct address_space *, loff_t,
+int cont_write_begin(const struct kiocb *, struct address_space *, loff_t,
 			unsigned, struct folio **, void **,
 			get_block_t *, loff_t *);
 int generic_cont_expand_simple(struct inode *inode, loff_t size);