Unverified Commit bfaa33b8 authored by David Howells's avatar David Howells Committed by Christian Brauner
Browse files

netfs: Provide an iterator-reset function 



Provide a function to reset the iterator on a subrequest.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20240814203850.2240469-17-dhowells@redhat.com/

 # v2
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent cd0277ed

fs/netfs/internal.h

+1 −3
Original line number Diff line number Diff line
@@ -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,

fs/netfs/misc.c

+18 −0
Original line number Diff line number Diff line
@@ -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.

fs/netfs/write_collect.c

+1 −2
Original line number Diff line number Diff line
@@ -226,9 +226,8 @@ 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. */

fs/netfs/write_issue.c

+3 −3
Original line number Diff line number Diff line
@@ -261,7 +261,7 @@ 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,

static int netfs_advance_write(struct netfs_io_request *wreq,

			       struct netfs_io_stream *stream,

			       loff_t start, size_t len, bool to_eof)

{