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Mon, 29 Jul 2024 16:22:00 +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 15/24] netfs: Provide an iterator-reset function Date: Mon, 29 Jul 2024 17:19:44 +0100 Message-ID: <20240729162002.3436763-16-dhowells@redhat.com> In-Reply-To: <20240729162002.3436763-1-dhowells@redhat.com> References: <20240729162002.3436763-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 --- 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 1700849491a0..a9baa46a17ff 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 d581fd8a568b..520be44d132e 100644 --- a/fs/netfs/write_issue.c +++ b/fs/netfs/write_issue.c @@ -259,9 +259,9 @@ 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;