From patchwork Mon Jan 16 23:07:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13103872 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D1E2C46467 for ; Mon, 16 Jan 2023 23:08:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233575AbjAPXIz (ORCPT ); Mon, 16 Jan 2023 18:08:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232060AbjAPXIy (ORCPT ); Mon, 16 Jan 2023 18:08:54 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 093DA1557B for ; Mon, 16 Jan 2023 15:08:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673910488; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=C0JW58nBSMHYj9bsnV2rJ7yxCnH8Mz39Aj6dzwUznZA=; b=BiTct47pgdzAG7IMAayl0oRevbF56Gm0zRP7n9/GFfOxjox1XeGMypfCSuoAKrYXuHJBcG uTlms8wzA4v77ngkkpQuLfg/gGsu7dmnVemhg+Z7AMjEEh77JrzYP93l5Q6nfD9SZbwH5t PfPJ5rRSDxa8xFn3YZLS4+zeGD7KU94= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-235-GJYj0EjBM4qvyti9d-2JNA-1; Mon, 16 Jan 2023 18:08:06 -0500 X-MC-Unique: GJYj0EjBM4qvyti9d-2JNA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B588C3815EE7; Mon, 16 Jan 2023 23:08:04 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 08299C15BA0; Mon, 16 Jan 2023 23:07:57 +0000 (UTC) Subject: [PATCH v6 00/34] iov_iter: Improve page extraction (ref, pin or just list) From: David Howells To: Al Viro Cc: "James E.J. Bottomley" , Paolo Abeni , John Hubbard , Christoph Hellwig , Paulo Alcantara , linux-scsi@vger.kernel.org, Steve French , Stefan Metzmacher , Miklos Szeredi , "Martin K. Petersen" , Logan Gunthorpe , Jeff Layton , Jakub Kicinski , netdev@vger.kernel.org, Rohith Surabattula , Eric Dumazet , Matthew Wilcox , Anna Schumaker , Jens Axboe , Shyam Prasad N , Tom Talpey , linux-rdma@vger.kernel.org, Trond Myklebust , Christian Schoenebeck , linux-mm@kvack.org, linux-crypto@vger.kernel.org, linux-nfs@vger.kernel.org, v9fs-developer@lists.sourceforge.net, Latchesar Ionkov , linux-fsdevel@vger.kernel.org, Eric Van Hensbergen , Long Li , Jan Kara , linux-cachefs@redhat.com, linux-block@vger.kernel.org, Dominique Martinet , Namjae Jeon , "David S. Miller" , linux-cifs@vger.kernel.org, Steve French , Herbert Xu , dhowells@redhat.com, Christoph Hellwig , Matthew Wilcox , Jens Axboe , Jan Kara , Jeff Layton , Logan Gunthorpe , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 16 Jan 2023 23:07:57 +0000 Message-ID: <167391047703.2311931.8115712773222260073.stgit@warthog.procyon.org.uk> User-Agent: StGit/1.5 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi Al, Christoph, Here are patches clean up some use of READ/WRITE and ITER_SOURCE/DEST, patches to provide support for extracting pages from an iov_iter and a patch to use the primary extraction function in the block layer bio code. I've also added a bunch of other conversions and had a tentative stab at the networking code. The patches make the following changes: (1) Deal with switching from using the iterator data_source to indicate the I/O direction to deriving this from other information, eg.: IOCB_WRITE, IOMAP_WRITE and the REQ_OP_* number. This allows iov_iter_rw() to be removed eventually. (2) Define FOLL_SOURCE_BUF and FOLL_DEST_BUF and pass these into iov_iter_get_pages*() to indicate the I/O direction with regards to how the buffer described by the iterator is to be used. This is included in the gup_flags passed in with Logan's patches. Calls to iov_iter_get_pages*2() are replaced with calls to iov_iter_get_pages*() and the former is removed. (3) Add a function, iov_iter_extract_pages() to replace iov_iter_get_pages*() that gets refs, pins or just lists the pages as appropriate to the iterator type and the I/O direction. Add a function, iov_iter_extract_mode() that will indicate from the iterator type and the I/O direction how the cleanup is to be performed, returning FOLL_GET, FOLL_PIN or 0. Add a function, folio_put_unpin(), and a wrapper, page_put_unpin(), that take a page and the return from iov_iter_extract_mode() and do the right thing to clean up the page. (4) Make the bio struct carry a pair of flags to indicate the cleanup mode. BIO_NO_PAGE_REF is replaced with BIO_PAGE_REFFED (equivalent to FOLL_GET) and BIO_PAGE_PINNED (equivalent to BIO_PAGE_PINNED) is added. These are forced to have the same value as the FOLL_* flags so they can be passed to the previously mentioned cleanup function. (5) Make the iter-to-bio code use iov_iter_extract_pages() to appropriately retain the pages and clean them up later. (6) Fix bio_flagged() so that it doesn't prevent a gcc optimisation. (7) Add a function in netfslib, netfs_extract_user_iter(), to extract a UBUF- or IOVEC-type iterator to a page list in a BVEC-type iterator, with all the pages suitably ref'd or pinned. (8) Add a function in netfslib, netfs_extract_iter_to_sg(), to extract a UBUF-, IOVEC-, BVEC-, XARRAY- or KVEC-type iterator to a scatterlist. The first two types appropriately ref or pin pages; the latter three don't perform any retention, leaving that to the caller. Note that I can make use of this in the SCSI and AF_ALG code and possibly the networking code, so this might merit being moved to core code. (9) Make AF_ALG use iov_iter_extract_pages() and possibly go further and make it use netfs_extract_iter_to_sg() instead. (10) Make SCSI vhost use netfs_extract_iter_to_sg(). (11) Make fs/direct-io.c use iov_iter_extract_pages(). (13) Make splice-to-pipe use iov_iter_extract_pages(), but limit the usage to a cleanup mode of FOLL_GET. (13) Make the 9P, FUSE and NFS filesystems use iov_iter_extract_pages(). (14) Make the CIFS filesystem use iterators from the top all the way down to the socket on the simple path. Make it use netfs_extract_user_iter() to use an XARRAY-type iterator or to build a BVEC-type iterator in the top layers from a UBUF- or IOVEC-type iterator and attach the iterator to the operation descriptors. netfs_extract_iter_to_sg() is used to build scatterlists for doing transport crypto and a function, smb_extract_iter_to_rdma(), is provided to build an RDMA SGE list directly from an iterator without going via a page list and then a scatter list. (15) A couple of work-in-progress patches to try and make sk_buff fragments record the information needed to clean them up in the lowest two bits of the page pointer in the fragment struct. This leaves: (*) Four calls to iov_iter_get_pages() in CEPH. That will be helped by patches to pass an iterator down to the transport layer instead of converting to a page list high up and passing that down, but the transport layer could do with some massaging so that it doesn't covert the iterator to a page list and then the pages individually back to iterators to pass to the socket. (*) One call to iov_iter_get_pages() each in the networking core, RDS and TLS, all related to zero-copy. TLS seems to do zerocopy-read (or maybe decrypt-offload) and should be doing FOLL_PIN, not FOLL_GET for user-provided buffers. Changes: ======== ver #6) - Fix write() syscall and co. not setting IOCB_WRITE. - Added iocb_is_read() and iocb_is_write() to check IOCB_WRITE. - Use op_is_write() in bio_copy_user_iov(). - Drop the iterator direction checks from smbd_recv(). - Define FOLL_SOURCE_BUF and FOLL_DEST_BUF and pass them in as part of gup_flags to iov_iter_get/extract_pages*(). - Replace iov_iter_get_pages*2() with iov_iter_get_pages*() and remove. - Add back the function to indicate the cleanup mode. - Drop the cleanup_mode return arg to iov_iter_extract_pages(). - Provide a helper to clean up a page. - Renumbered FOLL_GET and FOLL_PIN and made BIO_PAGE_REFFED/PINNED have the same numerical values, enforced with an assertion. - Converted AF_ALG, SCSI vhost, generic DIO, FUSE, splice to pipe, 9P and NFS. - Added in the patches to make CIFS do top-to-bottom iterators and use various of the added extraction functions. - Added a pair of work-in-progess patches to make sk_buff fragments store FOLL_GET and FOLL_PIN. ver #5) - Replace BIO_NO_PAGE_REF with BIO_PAGE_REFFED and split into own patch. - Transcribe FOLL_GET/PIN into BIO_PAGE_REFFED/PINNED flags. - Add patch to allow bio_flagged() to be combined by gcc. ver #4) - Drop the patch to move the FOLL_* flags to linux/mm_types.h as they're no longer referenced by linux/uio.h. - Add ITER_SOURCE/DEST cleanup patches. - Make iov_iter/netfslib iter extraction patches use ITER_SOURCE/DEST. - Allow additional gup_flags to be passed into iov_iter_extract_pages(). - Add struct bio patch. ver #3) - Switch to using EXPORT_SYMBOL_GPL to prevent indirect 3rd-party access to get/pin_user_pages_fast()[1]. ver #2) - Rolled the extraction cleanup mode query function into the extraction function, returning the indication through the argument list. - Fixed patch 4 (extract to scatterlist) to actually use the new extraction API. I've pushed the patches (excluding the two WIP networking patches) here also: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=iov-extract David Link: https://lore.kernel.org/r/Y3zFzdWnWlEJ8X8/@infradead.org/ [1] Link: https://lore.kernel.org/r/166697254399.61150.1256557652599252121.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/166722777223.2555743.162508599131141451.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/166732024173.3186319.18204305072070871546.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/166869687556.3723671.10061142538708346995.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/166920902005.1461876.2786264600108839814.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/166997419665.9475.15014699817597102032.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/167305160937.1521586.133299343565358971.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/167344725490.2425628.13771289553670112965.stgit@warthog.procyon.org.uk/ # v5 Previous versions of the CIFS patch sets can be found here: Link: https://lore.kernel.org/r/164311902471.2806745.10187041199819525677.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/164928615045.457102.10607899252434268982.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/165211416682.3154751.17287804906832979514.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/165348876794.2106726.9240233279581920208.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/165364823513.3334034.11209090728654641458.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/166126392703.708021.14465850073772688008.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/166697254399.61150.1256557652599252121.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/166732024173.3186319.18204305072070871546.stgit@warthog.procyon.org.uk/ # rfc --- David Howells (34): vfs: Unconditionally set IOCB_WRITE in call_write_iter() iov_iter: Use IOCB/IOMAP_WRITE/op_is_write rather than iterator direction iov_iter: Pass I/O direction into iov_iter_get_pages*() iov_iter: Remove iov_iter_get_pages2/pages_alloc2() iov_iter: Change the direction macros into an enum iov_iter: Use the direction in the iterator functions iov_iter: Add a function to extract a page list from an iterator mm: Provide a helper to drop a pin/ref on a page bio: Rename BIO_NO_PAGE_REF to BIO_PAGE_REFFED and invert the meaning mm, block: Make BIO_PAGE_REFFED/PINNED the same as FOLL_GET/PIN numerically iov_iter, block: Make bio structs pin pages rather than ref'ing if appropriate bio: Fix bio_flagged() so that gcc can better optimise it netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator netfs: Add a function to extract an iterator into a scatterlist af_alg: Pin pages rather than ref'ing if appropriate af_alg: [RFC] Use netfs_extract_iter_to_sg() to create scatterlists scsi: [RFC] Use netfs_extract_iter_to_sg() dio: Pin pages rather than ref'ing if appropriate fuse: Pin pages rather than ref'ing if appropriate vfs: Make splice use iov_iter_extract_pages() 9p: Pin pages rather than ref'ing if appropriate nfs: Pin pages rather than ref'ing if appropriate cifs: Implement splice_read to pass down ITER_BVEC not ITER_PIPE cifs: Add a function to build an RDMA SGE list from an iterator cifs: Add a function to Hash the contents of an iterator cifs: Add some helper functions cifs: Add a function to read into an iter from a socket cifs: Change the I/O paths to use an iterator rather than a page list cifs: Build the RDMA SGE list directly from an iterator cifs: Remove unused code cifs: Fix problem with encrypted RDMA data read cifs: DIO to/from KVEC-type iterators should now work net: [RFC][WIP] Mark each skb_frags as to how they should be cleaned up net: [RFC][WIP] Make __zerocopy_sg_from_iter() correctly pin or leave pages unref'd block/bio.c | 48 +- block/blk-map.c | 26 +- block/blk.h | 25 + block/fops.c | 8 +- crypto/af_alg.c | 57 +- crypto/algif_hash.c | 20 +- drivers/net/tun.c | 2 +- drivers/vhost/scsi.c | 75 +- fs/9p/vfs_addr.c | 2 +- fs/affs/file.c | 4 +- fs/ceph/addr.c | 2 +- fs/ceph/file.c | 16 +- fs/cifs/Kconfig | 1 + fs/cifs/cifsencrypt.c | 172 +++- fs/cifs/cifsfs.c | 12 +- fs/cifs/cifsfs.h | 6 + fs/cifs/cifsglob.h | 66 +- fs/cifs/cifsproto.h | 11 +- fs/cifs/cifssmb.c | 13 +- fs/cifs/connect.c | 16 + fs/cifs/file.c | 1851 +++++++++++++++++-------------------- fs/cifs/fscache.c | 22 +- fs/cifs/fscache.h | 10 +- fs/cifs/misc.c | 132 +-- fs/cifs/smb2ops.c | 374 ++++---- fs/cifs/smb2pdu.c | 45 +- fs/cifs/smbdirect.c | 511 ++++++---- fs/cifs/smbdirect.h | 4 +- fs/cifs/transport.c | 57 +- fs/dax.c | 6 +- fs/direct-io.c | 77 +- fs/exfat/inode.c | 6 +- fs/ext2/inode.c | 2 +- fs/f2fs/file.c | 10 +- fs/fat/inode.c | 4 +- fs/fuse/dax.c | 2 +- fs/fuse/dev.c | 24 +- fs/fuse/file.c | 34 +- fs/fuse/fuse_i.h | 1 + fs/hfs/inode.c | 2 +- fs/hfsplus/inode.c | 2 +- fs/iomap/direct-io.c | 6 +- fs/jfs/inode.c | 2 +- fs/netfs/Makefile | 1 + fs/netfs/iterator.c | 371 ++++++++ fs/nfs/direct.c | 32 +- fs/nilfs2/inode.c | 2 +- fs/ntfs3/inode.c | 2 +- fs/ocfs2/aops.c | 2 +- fs/orangefs/inode.c | 2 +- fs/reiserfs/inode.c | 2 +- fs/splice.c | 10 +- fs/udf/inode.c | 2 +- include/crypto/if_alg.h | 7 +- include/linux/bio.h | 23 +- include/linux/blk_types.h | 3 +- include/linux/fs.h | 11 + include/linux/mm.h | 32 +- include/linux/netfs.h | 6 + include/linux/skbuff.h | 124 ++- include/linux/uio.h | 83 +- io_uring/net.c | 2 +- lib/iov_iter.c | 428 ++++++++- mm/gup.c | 47 + mm/vmalloc.c | 1 + net/9p/trans_common.c | 6 +- net/9p/trans_common.h | 3 +- net/9p/trans_virtio.c | 91 +- net/bpf/test_run.c | 2 +- net/core/datagram.c | 23 +- net/core/gro.c | 2 +- net/core/skbuff.c | 16 +- net/core/skmsg.c | 4 +- net/ipv4/ip_output.c | 2 +- net/ipv4/tcp.c | 4 +- net/ipv6/esp6.c | 5 +- net/ipv6/ip6_output.c | 2 +- net/packet/af_packet.c | 2 +- net/rds/message.c | 4 +- net/tls/tls_sw.c | 5 +- net/xfrm/xfrm_ipcomp.c | 2 +- 81 files changed, 3006 insertions(+), 2126 deletions(-) create mode 100644 fs/netfs/iterator.c