On Tue, Sep 08, 2026 at 02:04:41PM -0700, Viacheslav Dubeyko wrote:
> This series moves HFS+ regular file data I/O off the legacy
> buffer_head/blockdev_direct_IO() path onto iomap-based operations with
> the goal to retire the older buffer_head-based direct I/O infrastructure.
>
> v2
> Christoph Hellwig has detected that taking the page lock around
> the kmap/modify/kunmap section is not enough on its own:
> writeback drops the page lock before the write actually completes,
> so a mutator that only waits on the lock can still start rewriting
> a page whose old contents are still in flight to the device.
> Mark the allocation file's mapping with mapping_set_stable_writes()
> and call folio_wait_stable() right after taking the page lock in
> both functions, so a mutator also waits out any writeback that was
> already in progress when it acquired the lock.
>
> Christoph Hellwig suggested to introduce a generalized version
> of iomap_dio_end_io() that was placed into include/linux/iomap.h.
>
> The hfsplus_btree_aops uses hfsplus_btree_read_folio() and
> hfsplus_btree_writepages() methods. The hfsplus_symlink_aops
> uses hfsplus_symlink_read_folio() and hfsplus_symlink_writepages()
> methods. Also, hfsplus_setattr() doesn't distinguish the regular
> and not regular file cases anymore.
>
> v3
> Matthew Wilcox recommended to use folio_wait_writeback()
> instead of folio_wait_stable().
>
> Fix failures in generic/091, generic/521, and generic/551.
FWIW the iomap port itself looks correct to me, so for patches 4, 6,
and 7:
Acked-by: "Darrick J. Wong" <djwong@kernel.org>
but my knowledge of HFS+ is pretty fragmented now, so I couldn't say for
sure about 1-3 or 5.
--D
> Viacheslav Dubeyko (7):
> hfs/hfsplus: exchange hardcoded number of extents on named constants
> hfsplus: rework hfsplus_get_block() logic
> hfsplus: take the bitmap page lock for allocate/free
> hfsplus: add iomap operations for regular file data
> hfsplus: move file related operations to file.c
> hfsplus: introduce iomap-based file_operations
> hfsplus: switch address_space_operations on iomap-based support
>
> fs/hfsplus/Kconfig | 2 +-
> fs/hfsplus/Makefile | 5 +-
> fs/hfsplus/bitmap.c | 18 +++
> fs/hfsplus/extents.c | 164 ++++++++++++++------
> fs/hfsplus/file.c | 304 +++++++++++++++++++++++++++++++++++++
> fs/hfsplus/hfsplus_fs.h | 26 +++-
> fs/hfsplus/inode.c | 281 ++++++++++------------------------
> fs/hfsplus/iomap.c | 192 +++++++++++++++++++++++
> fs/hfsplus/iomap.h | 18 +++
> include/linux/hfs_common.h | 8 +-
> include/linux/iomap.h | 20 +++
> 11 files changed, 787 insertions(+), 251 deletions(-)
> create mode 100644 fs/hfsplus/file.c
> create mode 100644 fs/hfsplus/iomap.c
> create mode 100644 fs/hfsplus/iomap.h
>
> --
> 2.43.0
>