From patchwork Wed Aug 14 20:38:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13764080 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C2E191DD38B for ; Wed, 14 Aug 2024 20:41:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723668071; cv=none; b=pEZnjHBRiAtodjDXQFPrBNGi9QTspdkbm5pR5kdnH5CxVNqT1cifibgmkf38vJsh0bKFBNvRMxJNhMuzPvngXeTHYIFaW6UxySG4PWK8My3cQjZEGZCMmEOqMXHYeetzt9PhtpLc36terioSUDGAhTKUWqrUW9wT3DkMYcD4/fc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723668071; c=relaxed/simple; bh=rA7Q3ScE2LCp3jy3wxNYV6fI8svKOnzxOnvE2IAegRQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ghyh3cvCf/Pn0wm7u6o4XuexJzNsvyM1fZYzhNwZu95YjsbCUT3PHcDXE4GasqtuVC16C2C6R1RBXVsAF7sQoyYmhBvtUg63pGadMML0v9hY7/Q8zSv4pwQGDGhku+siH1FHXW4+Rd9OdV8enVNWmlJeMrqCxfgT8JKVLXTh8vw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=eV7bEnim; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eV7bEnim" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1723668069; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/5GudhtF+T887yYtTq2ccnSMC605t1SyQsaR8Y8Wa80=; b=eV7bEnimPr44DR3huxoGX9iPjZ9FH3FSeyxavizzGgFzrFC1rMYQYk8FSvQkzPOPW5yCF3 SBWk0N4R8P98qaJUAwhfk6gAi7/a5/z5u6usS6G9aPIUMD9u343A6PGzA0zQ5HqAyz09UX Fhb+/DFLBCX7cEjBlJ0msjAe9HGIjqw= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-378-cuSPPapgNmmADvVkpaXVwA-1; Wed, 14 Aug 2024 16:41:05 -0400 X-MC-Unique: cuSPPapgNmmADvVkpaXVwA-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 837281954B0E; Wed, 14 Aug 2024 20:41:02 +0000 (UTC) Received: from warthog.procyon.org.uk.com (unknown [10.42.28.30]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id E3421300019A; Wed, 14 Aug 2024 20:40:56 +0000 (UTC) From: David Howells To: Christian Brauner , Steve French , Matthew Wilcox Cc: David Howells , Jeff Layton , Gao Xiang , Dominique Martinet , Marc Dionne , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Eric Van Hensbergen , Ilya Dryomov , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 16/25] netfs: Provide an iterator-reset function Date: Wed, 14 Aug 2024 21:38:36 +0100 Message-ID: <20240814203850.2240469-17-dhowells@redhat.com> In-Reply-To: <20240814203850.2240469-1-dhowells@redhat.com> References: <20240814203850.2240469-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: v9fs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Provide a function to reset the iterator on a subrequest. Signed-off-by: David Howells cc: Jeff Layton cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org --- fs/netfs/internal.h | 4 +--- fs/netfs/misc.c | 18 ++++++++++++++++++ fs/netfs/write_collect.c | 3 +-- fs/netfs/write_issue.c | 6 +++--- 4 files changed, 23 insertions(+), 8 deletions(-) diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index e1149e05a5c8..21a3c7d13585 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -69,6 +69,7 @@ int netfs_buffer_append_folio(struct netfs_io_request *rreq, struct folio *folio bool needs_put); struct folio_queue *netfs_delete_buffer_head(struct netfs_io_request *wreq); void netfs_clear_buffer(struct netfs_io_request *rreq); +void netfs_reset_iter(struct netfs_io_subrequest *subreq); /* * objects.c @@ -161,9 +162,6 @@ struct netfs_io_request *netfs_create_write_req(struct address_space *mapping, void netfs_reissue_write(struct netfs_io_stream *stream, struct netfs_io_subrequest *subreq, struct iov_iter *source); -int netfs_advance_write(struct netfs_io_request *wreq, - struct netfs_io_stream *stream, - loff_t start, size_t len, bool to_eof); struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len); int netfs_advance_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc, struct folio *folio, size_t copied, bool to_page_end, diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c index e642e5cacb8d..08987765306f 100644 --- a/fs/netfs/misc.c +++ b/fs/netfs/misc.c @@ -84,6 +84,24 @@ void netfs_clear_buffer(struct netfs_io_request *rreq) } } +/* + * Reset the subrequest iterator to refer just to the region remaining to be + * read. The iterator may or may not have been advanced by socket ops or + * extraction ops to an extent that may or may not match the amount actually + * read. + */ +void netfs_reset_iter(struct netfs_io_subrequest *subreq) +{ + struct iov_iter *io_iter = &subreq->io_iter; + size_t remain = subreq->len - subreq->transferred; + + if (io_iter->count > remain) + iov_iter_advance(io_iter, io_iter->count - remain); + else if (io_iter->count < remain) + iov_iter_revert(io_iter, remain - io_iter->count); + iov_iter_truncate(&subreq->io_iter, remain); +} + /** * netfs_dirty_folio - Mark folio dirty and pin a cache object for writeback * @mapping: The mapping the folio belongs to. diff --git a/fs/netfs/write_collect.c b/fs/netfs/write_collect.c index 1521a23077c3..801a130a0ce1 100644 --- a/fs/netfs/write_collect.c +++ b/fs/netfs/write_collect.c @@ -219,9 +219,8 @@ static void netfs_retry_write_stream(struct netfs_io_request *wreq, /* Determine the set of buffers we're going to use. Each * subreq gets a subset of a single overall contiguous buffer. */ + netfs_reset_iter(from); source = from->io_iter; - iov_iter_revert(&source, subreq->len - source.count); - iov_iter_advance(&source, from->transferred); source.count = len; /* Work through the sublist. */ diff --git a/fs/netfs/write_issue.c b/fs/netfs/write_issue.c index a75b62b202c5..9ead075962f0 100644 --- a/fs/netfs/write_issue.c +++ b/fs/netfs/write_issue.c @@ -261,9 +261,9 @@ static void netfs_issue_write(struct netfs_io_request *wreq, * we can avoid overrunning the credits obtained (cifs) and try to parallelise * content-crypto preparation with network writes. */ -int netfs_advance_write(struct netfs_io_request *wreq, - struct netfs_io_stream *stream, - loff_t start, size_t len, bool to_eof) +static int netfs_advance_write(struct netfs_io_request *wreq, + struct netfs_io_stream *stream, + loff_t start, size_t len, bool to_eof) { struct netfs_io_subrequest *subreq = stream->construct; size_t part;