[PATCH v4 0/5] fs: refactor write_begin/write_end and add ext4 IOCB_DONTCACHE support

[陈涛涛 Taotao Chen]

From: Taotao Chen <chentaotao at didiglobal.com>

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.

This patch series is based on the vfs-6.17.misc branch.

Changes since v3:
- Added write_begin_get_folio() helper and updated ext4 to use it.
- Refactored exfat_extend_valid_size() to take inode instead of file, and
  removed unnecessary kiocb usage in exfat and ntfs.

Taotao Chen (5):
  drm/i915: Use kernel_write() in shmem object create
  drm/i915: Refactor shmem_pwrite() to use kiocb and write_iter
  fs: change write_begin/write_end interface to take struct kiocb *
  mm/filemap: add write_begin_get_folio() helper function
  ext4: support uncached buffered I/O

 Documentation/filesystems/locking.rst     |   4 +-
 Documentation/filesystems/vfs.rst         |   6 +-
 block/fops.c                              |  13 ++-
 drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 114 ++++++----------------
 fs/adfs/inode.c                           |   9 +-
 fs/affs/file.c                            |  26 ++---
 fs/bcachefs/fs-io-buffered.c              |   4 +-
 fs/bcachefs/fs-io-buffered.h              |   4 +-
 fs/bfs/file.c                             |   7 +-
 fs/buffer.c                               |  26 ++---
 fs/ceph/addr.c                            |  10 +-
 fs/ecryptfs/mmap.c                        |  10 +-
 fs/exfat/file.c                           |  11 +--
 fs/exfat/inode.c                          |  16 +--
 fs/ext2/inode.c                           |  11 ++-
 fs/ext4/file.c                            |   3 +-
 fs/ext4/inode.c                           |  30 +++---
 fs/f2fs/data.c                            |   8 +-
 fs/fat/inode.c                            |  18 ++--
 fs/fuse/file.c                            |  14 ++-
 fs/hfs/hfs_fs.h                           |   2 +-
 fs/hfs/inode.c                            |   4 +-
 fs/hfsplus/hfsplus_fs.h                   |   6 +-
 fs/hfsplus/inode.c                        |   8 +-
 fs/hostfs/hostfs_kern.c                   |   8 +-
 fs/hpfs/file.c                            |  18 ++--
 fs/hugetlbfs/inode.c                      |   9 +-
 fs/jffs2/file.c                           |  28 +++---
 fs/jfs/inode.c                            |  16 +--
 fs/libfs.c                                |  11 ++-
 fs/minix/inode.c                          |   7 +-
 fs/nfs/file.c                             |   8 +-
 fs/nilfs2/inode.c                         |   8 +-
 fs/ntfs3/file.c                           |   4 +-
 fs/ntfs3/inode.c                          |   7 +-
 fs/ntfs3/ntfs_fs.h                        |  10 +-
 fs/ocfs2/aops.c                           |   6 +-
 fs/omfs/file.c                            |   7 +-
 fs/orangefs/inode.c                       |  16 +--
 fs/ubifs/file.c                           |   5 +-
 fs/udf/inode.c                            |  11 ++-
 fs/ufs/inode.c                            |  16 +--
 fs/vboxsf/file.c                          |   5 +-
 include/linux/buffer_head.h               |   4 +-
 include/linux/fs.h                        |  11 ++-
 include/linux/pagemap.h                   |   3 +
 mm/filemap.c                              |  34 ++++++-
 mm/shmem.c                                |  12 +--
 48 files changed, 333 insertions(+), 295 deletions(-)

-- 
2.34.1