[PATCH v2 0/4] iov_iter: Adjust styling/location of new splice functions

From: David Howells
Date: Mon Feb 13 2023 - 10:34:11 EST


Hi Jens, Al, Christoph,

Here are patches to make some changes that Christoph requested[1] to the
new generic file splice functions that I implemented[2]. Apart from one
functional change, they just altering the styling and move one of the
functions to a different file:

(1) Rename the main functions:

generic_file_buffered_splice_read() -> filemap_splice_read()
generic_file_direct_splice_read() -> direct_splice_read()

(2) Abstract out the calculation of the location of the head pipe buffer
into a helper function in linux/pipe_fs_i.h.

(3) Use init_sync_kiocb() in filemap_splice_read().

This is where the functional change is. Some kiocb fields are then
filled in where they were set to 0 before, including setting ki_flags
from f_iocb_flags. I've filtered out IOCB_NOWAIT as the function is
supposed to be synchronous.

(4) Move filemap_splice_read() to mm/filemap.c. filemap_get_pages() can
then be made static again.

I've pushed the patches here also:

https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=iov-extract-3

I've also updated worked the changes into the commits on my iov-extract
branch if that would be preferable, though that means Jens would need to
update his for-6.3/iov-extract again.

David

Link: https://lore.kernel.org/r/Y+n0n2UE8BQa/OwW@xxxxxxxxxxxxx/ [1]
Link: https://lore.kernel.org/r/20230207171305.3716974-1-dhowells@xxxxxxxxxx/ [2]

Changes
=======
ver #2)
- Don't attempt to filter IOCB_* flags in filemap_splice_read().

Link: https://lore.kernel.org/r/20230213134619.2198965-1-dhowells@xxxxxxxxxx/ # v1

David Howells (4):
splice: Rename new splice functions
splice: Provide pipe_head_buf() helper
splice: Use init_sync_kiocb() in filemap_splice_read()
splice: Move filemap_read_splice() to mm/filemap.c

fs/splice.c | 146 ++------------------------------------
include/linux/pagemap.h | 2 -
include/linux/pipe_fs_i.h | 20 ++++++
include/linux/splice.h | 4 ++
mm/filemap.c | 137 +++++++++++++++++++++++++++++++++--
5 files changed, 162 insertions(+), 147 deletions(-)