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

陈涛涛 Taotao Chen
2025-07-07T07:00:55Z

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(-)

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2.34.1