Here's the fourth tranche of patches towards providing a MSG_SPLICE_PAGES
internal sendmsg flag that is intended to replace the ->sendpage() op with
calls to sendmsg(). MSG_SPLICE_PAGES is a hint that tells the protocol
that it should splice the pages supplied if it can.
This set consists of the following parts:
(1) Move netfs_extract_iter_to_sg() to somewhere more general and rename
it to drop the "netfs" prefix. We use this to extract directly from
an iterator into a scatterlist.
(2) Make AF_ALG use iov_iter_extract_pages(). This has the additional
effect of pinning pages obtained from userspace rather than taking
refs on them. Pages from kernel-backed iterators would not be pinned,
but AF_ALG isn't really meant for use by kernel services.
(3) Change AF_ALG still further to use extract_iter_to_sg().
(4) Make af_alg_sendmsg() support MSG_SPLICE_PAGES support and make
af_alg_sendpage() just a wrapper around sendmsg(). This has to take
refs on the pages pinned for the moment.
(5) Make hash_sendmsg() support MSG_SPLICE_PAGES by simply ignoring it.
hash_sendpage() is left untouched to be removed later, after the
splice core has been changed to call sendmsg().
I've pushed the patches here also:
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=sendpage-4
David
Link: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=51c78a4d532efe9543a4df019ff405f05c6157f6 # part 1
David Howells (8):
Move netfs_extract_iter_to_sg() to lib/scatterlist.c
Drop the netfs_ prefix from netfs_extract_iter_to_sg()
crypto: af_alg: Pin pages rather than ref'ing if appropriate
crypto: af_alg: Use extract_iter_to_sg() to create scatterlists
crypto: af_alg: Indent the loop in af_alg_sendmsg()
crypto: af_alg: Support MSG_SPLICE_PAGES
crypto: af_alg: Convert af_alg_sendpage() to use MSG_SPLICE_PAGES
crypto: af_alg/hash: Support MSG_SPLICE_PAGES
crypto/af_alg.c | 183 +++++++++++-------------
crypto/algif_aead.c | 34 ++---
crypto/algif_hash.c | 110 +++++++++------
crypto/algif_skcipher.c | 10 +-
fs/cifs/smb2ops.c | 4 +-
fs/cifs/smbdirect.c | 2 +-
fs/netfs/iterator.c | 266 -----------------------------------
include/crypto/if_alg.h | 7 +-
include/linux/netfs.h | 4 -
include/linux/scatterlist.h | 1 +
include/linux/uio.h | 5 +
lib/scatterlist.c | 267 ++++++++++++++++++++++++++++++++++++
12 files changed, 449 insertions(+), 444 deletions(-)
