Unverified Commit 2b1424cd authored by David Howells's avatar David Howells Committed by Christian Brauner
Browse files

netfs: Fix wait/wake to be consistent about the waitqueue used 



Fix further inconsistencies in the use of waitqueues
(clear_and_wake_up_bit() vs private waitqueue).

Move some of this stuff from the read and write sides into common code so
that it can be done in fewer places.

To make this work, async I/O needs to set NETFS_RREQ_OFFLOAD_COLLECTION to
indicate that a workqueue will do the collecting and places that call the
wait function need to deal with it returning the amount transferred.

Fixes: e2d46f2e ("netfs: Change the read result collector to only use one work item")
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/20250519090707.2848510-5-dhowells@redhat.com


cc: Marc Dionne <marc.dionne@auristor.com>
cc: Steve French <stfrench@microsoft.com>
cc: Ihor Solodrai <ihor.solodrai@pm.me>
cc: Eric Van Hensbergen <ericvh@kernel.org>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: v9fs@lists.linux.dev
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 20d72b00

fs/netfs/buffered_read.c

+1 −1
Original line number Diff line number Diff line
@@ -312,7 +312,7 @@ static void netfs_read_to_pagecache(struct netfs_io_request *rreq) 
	if (unlikely(size > 0)) {

		smp_wmb(); /* Write lists before ALL_QUEUED. */

		set_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags);

		netfs_wake_read_collector(rreq);

		netfs_wake_collector(rreq);

	}



	/* Defer error return as we may need to wait for outstanding I/O. */

fs/netfs/buffered_write.c

+1 −1
Original line number Diff line number Diff line
@@ -386,7 +386,7 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter, 
		wbc_detach_inode(&wbc);

		if (ret2 == -EIOCBQUEUED)

			return ret2;

		if (ret == 0)

		if (ret == 0 && ret2 < 0)

			ret = ret2;

	}

fs/netfs/direct_read.c

+2 −2
Original line number Diff line number Diff line
@@ -103,7 +103,7 @@ static int netfs_dispatch_unbuffered_reads(struct netfs_io_request *rreq) 
		rreq->netfs_ops->issue_read(subreq);



		if (test_bit(NETFS_RREQ_PAUSE, &rreq->flags))

			netfs_wait_for_pause(rreq);

			netfs_wait_for_paused_read(rreq);

		if (test_bit(NETFS_RREQ_FAILED, &rreq->flags))

			break;

		if (test_bit(NETFS_RREQ_BLOCKED, &rreq->flags) &&
@@ -115,7 +115,7 @@ static int netfs_dispatch_unbuffered_reads(struct netfs_io_request *rreq) 
	if (unlikely(size > 0)) {

		smp_wmb(); /* Write lists before ALL_QUEUED. */

		set_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags);

		netfs_wake_read_collector(rreq);

		netfs_wake_collector(rreq);

	}



	return ret;

fs/netfs/direct_write.c

+4 −6
Original line number Diff line number Diff line
@@ -87,6 +87,8 @@ ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter * 
	}



	__set_bit(NETFS_RREQ_USE_IO_ITER, &wreq->flags);

	if (async)

		__set_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &wreq->flags);



	/* Copy the data into the bounce buffer and encrypt it. */

	// TODO
@@ -105,13 +107,9 @@ ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter * 


	if (!async) {

		trace_netfs_rreq(wreq, netfs_rreq_trace_wait_ip);

		wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,

			    TASK_UNINTERRUPTIBLE);

		ret = wreq->error;

		if (ret == 0) {

			ret = wreq->transferred;

		ret = netfs_wait_for_write(wreq);

		if (ret > 0)

			iocb->ki_pos += ret;

		}

	} else {

		ret = -EIOCBQUEUED;

	}

fs/netfs/internal.h

+27 −6
Original line number Diff line number Diff line
@@ -62,6 +62,14 @@ static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {} 
struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq,

					    enum netfs_folioq_trace trace);

void netfs_reset_iter(struct netfs_io_subrequest *subreq);

void netfs_wake_collector(struct netfs_io_request *rreq);

void netfs_subreq_clear_in_progress(struct netfs_io_subrequest *subreq);

void netfs_wait_for_in_progress_stream(struct netfs_io_request *rreq,

				       struct netfs_io_stream *stream);

ssize_t netfs_wait_for_read(struct netfs_io_request *rreq);

ssize_t netfs_wait_for_write(struct netfs_io_request *rreq);

void netfs_wait_for_paused_read(struct netfs_io_request *rreq);

void netfs_wait_for_paused_write(struct netfs_io_request *rreq);



/*

 * objects.c
@@ -91,11 +99,9 @@ static inline void netfs_see_subrequest(struct netfs_io_subrequest *subreq, 
/*

 * read_collect.c

 */

bool netfs_read_collection(struct netfs_io_request *rreq);

void netfs_read_collection_worker(struct work_struct *work);

void netfs_wake_read_collector(struct netfs_io_request *rreq);

void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error);

ssize_t netfs_wait_for_read(struct netfs_io_request *rreq);

void netfs_wait_for_pause(struct netfs_io_request *rreq);



/*

 * read_pgpriv2.c
@@ -175,8 +181,8 @@ static inline void netfs_stat_d(atomic_t *stat) 
 * write_collect.c

 */

int netfs_folio_written_back(struct folio *folio);

bool netfs_write_collection(struct netfs_io_request *wreq);

void netfs_write_collection_worker(struct work_struct *work);

void netfs_wake_write_collector(struct netfs_io_request *wreq);



/*

 * write_issue.c
@@ -197,7 +203,7 @@ 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,

			       struct folio **writethrough_cache);

int netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,

ssize_t netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,

			       struct folio *writethrough_cache);

int netfs_unbuffered_write(struct netfs_io_request *wreq, bool may_wait, size_t len);
@@ -253,6 +259,21 @@ static inline void netfs_put_group_many(struct netfs_group *netfs_group, int nr) 
		netfs_group->free(netfs_group);

}



/*

 * Clear and wake up a NETFS_RREQ_* flag bit on a request.

 */

static inline void netfs_wake_rreq_flag(struct netfs_io_request *rreq,

					unsigned int rreq_flag,

					enum netfs_rreq_trace trace)

{

	if (test_bit(rreq_flag, &rreq->flags)) {

		trace_netfs_rreq(rreq, trace);

		clear_bit_unlock(rreq_flag, &rreq->flags);

		smp_mb__after_atomic(); /* Set flag before task state */

		wake_up(&rreq->waitq);

	}

}



/*

 * fscache-cache.c

 */