netfs: Fix the request's work item to not require a ref

When the netfs_io_request struct's work item is queued, it must be supplied
with a ref to the work item struct to prevent it being deallocated whilst
on the queue or whilst it is being processed.  This is tricky to manage as
we have to get a ref before we try and queue it and then we may find it's
already queued and is thus already holding a ref - in which case we have to
try and get rid of the ref again.

The problem comes if we're in BH or IRQ context and need to drop the ref:
if netfs_put_request() reduces the count to 0, we have to do the cleanup -
but the cleanup may need to wait.

Fix this by adding a new work item to the request, ->cleanup_work, and
dispatching that when the refcount hits zero.  That can then synchronously
cancel any outstanding work on the main work item before doing the cleanup.

Adding a new work item also deals with another problem upstream where it's
sometimes changing the work func in the put function and requeuing it -
which has occasionally in the past caused the cleanup to happen
incorrectly.

As a bonus, this allows us to get rid of the 'was_async' parameter from a
bunch of functions.  This indicated whether the put function might not be
permitted to sleep.

Fixes: 3d3c95046742 ("netfs: Provide readahead and readpage netfs helpers")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/20250519090707.2848510-4-dhowells@redhat.com
cc: Paulo Alcantara <pc@manguebit.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Steve French <stfrench@microsoft.com>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

13 files changed, 122 insertions, 119 deletions

diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 0d1b6d35ff3b8..cb6202efc4668 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -262,9 +262,9 @@ static void netfs_read_to_pagecache(struct netfs_io_request *rreq)
 				if (ret < 0) {
 					subreq->error = ret;
 					/* Not queued - release both refs. */
-					netfs_put_subrequest(subreq, false,
+					netfs_put_subrequest(subreq,
 							     netfs_sreq_trace_put_cancel);
-					netfs_put_subrequest(subreq, false,
+					netfs_put_subrequest(subreq,
 							     netfs_sreq_trace_put_cancel);
 					break;
 				}
@@ -297,8 +297,8 @@ static void netfs_read_to_pagecache(struct netfs_io_request *rreq)
 			subreq->error = ret;
 			trace_netfs_sreq(subreq, netfs_sreq_trace_cancel);
 			/* Not queued - release both refs. */
-			netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_cancel);
-			netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_cancel);
+			netfs_put_subrequest(subreq, netfs_sreq_trace_put_cancel);
+			netfs_put_subrequest(subreq, netfs_sreq_trace_put_cancel);
 			break;
 		}
 		size -= slice;
@@ -365,12 +365,10 @@ void netfs_readahead(struct readahead_control *ractl)
 		goto cleanup_free;
 	netfs_read_to_pagecache(rreq);
 
-	netfs_put_request(rreq, true, netfs_rreq_trace_put_return);
-	return;
+	return netfs_put_request(rreq, netfs_rreq_trace_put_return);
 
 cleanup_free:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_failed);
-	return;
+	return netfs_put_request(rreq, netfs_rreq_trace_put_failed);
 }
 EXPORT_SYMBOL(netfs_readahead);
 
@@ -470,11 +468,11 @@ static int netfs_read_gaps(struct file *file, struct folio *folio)
 		folio_mark_uptodate(folio);
 	}
 	folio_unlock(folio);
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(rreq, netfs_rreq_trace_put_return);
 	return ret < 0 ? ret : 0;
 
 discard:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_discard);
+	netfs_put_request(rreq, netfs_rreq_trace_put_discard);
 alloc_error:
 	folio_unlock(folio);
 	return ret;
@@ -530,11 +528,11 @@ int netfs_read_folio(struct file *file, struct folio *folio)
 
 	netfs_read_to_pagecache(rreq);
 	ret = netfs_wait_for_read(rreq);
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(rreq, netfs_rreq_trace_put_return);
 	return ret < 0 ? ret : 0;
 
 discard:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_discard);
+	netfs_put_request(rreq, netfs_rreq_trace_put_discard);
 alloc_error:
 	folio_unlock(folio);
 	return ret;
@@ -689,7 +687,7 @@ retry:
 	ret = netfs_wait_for_read(rreq);
 	if (ret < 0)
 		goto error;
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(rreq, netfs_rreq_trace_put_return);
 
 have_folio:
 	ret = folio_wait_private_2_killable(folio);
@@ -701,7 +699,7 @@ have_folio_no_wait:
 	return 0;
 
 error_put:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_failed);
+	netfs_put_request(rreq, netfs_rreq_trace_put_failed);
 error:
 	if (folio) {
 		folio_unlock(folio);
@@ -752,11 +750,11 @@ int netfs_prefetch_for_write(struct file *file, struct folio *folio,
 
 	netfs_read_to_pagecache(rreq);
 	ret = netfs_wait_for_read(rreq);
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(rreq, netfs_rreq_trace_put_return);
 	return ret < 0 ? ret : 0;
 
 error_put:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_discard);
+	netfs_put_request(rreq, netfs_rreq_trace_put_discard);
 error:
 	_leave(" = %d", ret);
 	return ret;
diff --git a/fs/netfs/direct_read.c b/fs/netfs/direct_read.c
index 5e3f0aeb51f31..cb3c6dc0b1654 100644
--- a/fs/netfs/direct_read.c
+++ b/fs/netfs/direct_read.c
@@ -85,7 +85,7 @@ static int netfs_dispatch_unbuffered_reads(struct netfs_io_request *rreq)
 		if (rreq->netfs_ops->prepare_read) {
 			ret = rreq->netfs_ops->prepare_read(subreq);
 			if (ret < 0) {
-				netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_cancel);
+				netfs_put_subrequest(subreq, netfs_sreq_trace_put_cancel);
 				break;
 			}
 		}
@@ -144,7 +144,7 @@ static ssize_t netfs_unbuffered_read(struct netfs_io_request *rreq, bool sync)
 	ret = netfs_dispatch_unbuffered_reads(rreq);
 
 	if (!rreq->submitted) {
-		netfs_put_request(rreq, false, netfs_rreq_trace_put_no_submit);
+		netfs_put_request(rreq, netfs_rreq_trace_put_no_submit);
 		inode_dio_end(rreq->inode);
 		ret = 0;
 		goto out;
@@ -236,7 +236,7 @@ ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_iter *i
 	}
 
 out:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(rreq, netfs_rreq_trace_put_return);
 	if (ret > 0)
 		orig_count -= ret;
 	return ret;
diff --git a/fs/netfs/direct_write.c b/fs/netfs/direct_write.c
index 42ce53cc216e9..c98f1676f86df 100644
--- a/fs/netfs/direct_write.c
+++ b/fs/netfs/direct_write.c
@@ -117,7 +117,7 @@ ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *
 	}
 
 out:
-	netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(wreq, netfs_rreq_trace_put_return);
 	return ret;
 }
 EXPORT_SYMBOL(netfs_unbuffered_write_iter_locked);
diff --git a/fs/netfs/fscache_io.c b/fs/netfs/fscache_io.c
index b1722a82c03d3..e4308457633ca 100644
--- a/fs/netfs/fscache_io.c
+++ b/fs/netfs/fscache_io.c
@@ -192,8 +192,7 @@ EXPORT_SYMBOL(__fscache_clear_page_bits);
 /*
  * Deal with the completion of writing the data to the cache.
  */
-static void fscache_wreq_done(void *priv, ssize_t transferred_or_error,
-			      bool was_async)
+static void fscache_wreq_done(void *priv, ssize_t transferred_or_error)
 {
 	struct fscache_write_request *wreq = priv;
 
@@ -202,8 +201,7 @@ static void fscache_wreq_done(void *priv, ssize_t transferred_or_error,
 					wreq->set_bits);
 
 	if (wreq->term_func)
-		wreq->term_func(wreq->term_func_priv, transferred_or_error,
-				was_async);
+		wreq->term_func(wreq->term_func_priv, transferred_or_error);
 	fscache_end_operation(&wreq->cache_resources);
 	kfree(wreq);
 }
@@ -255,14 +253,14 @@ void __fscache_write_to_cache(struct fscache_cookie *cookie,
 	return;
 
 abandon_end:
-	return fscache_wreq_done(wreq, ret, false);
+	return fscache_wreq_done(wreq, ret);
 abandon_free:
 	kfree(wreq);
 abandon:
 	if (using_pgpriv2)
 		fscache_clear_page_bits(mapping, start, len, cond);
 	if (term_func)
-		term_func(term_func_priv, ret, false);
+		term_func(term_func_priv, ret);
 }
 EXPORT_SYMBOL(__fscache_write_to_cache);
 
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 1c4f953c3d683..b6500a7cda81d 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -23,7 +23,7 @@
 /*
  * buffered_read.c
  */
-void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error, bool was_async);
+void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error);
 int netfs_prefetch_for_write(struct file *file, struct folio *folio,
 			     size_t offset, size_t len);
 
@@ -71,9 +71,8 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 					     loff_t start, size_t len,
 					     enum netfs_io_origin origin);
 void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
-void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async);
-void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
-		       enum netfs_rreq_ref_trace what);
+void netfs_clear_subrequests(struct netfs_io_request *rreq);
+void netfs_put_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
 struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq);
 
 static inline void netfs_see_request(struct netfs_io_request *rreq,
@@ -94,7 +93,7 @@ static inline void netfs_see_subrequest(struct netfs_io_subrequest *subreq,
  */
 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, bool was_async);
+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);
 
@@ -177,7 +176,7 @@ static inline void netfs_stat_d(atomic_t *stat)
  */
 int netfs_folio_written_back(struct folio *folio);
 void netfs_write_collection_worker(struct work_struct *work);
-void netfs_wake_write_collector(struct netfs_io_request *wreq, bool was_async);
+void netfs_wake_write_collector(struct netfs_io_request *wreq);
 
 /*
  * write_issue.c
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index dc6b41ef18b09..d3eb9ba3013a7 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -10,6 +10,8 @@
 #include <linux/delay.h>
 #include "internal.h"
 
+static void netfs_free_request(struct work_struct *work);
+
 /*
  * Allocate an I/O request and initialise it.
  */
@@ -34,6 +36,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 	}
 
 	memset(rreq, 0, kmem_cache_size(cache));
+	INIT_WORK(&rreq->cleanup_work, netfs_free_request);
 	rreq->start	= start;
 	rreq->len	= len;
 	rreq->origin	= origin;
@@ -49,7 +52,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 	INIT_LIST_HEAD(&rreq->io_streams[0].subrequests);
 	INIT_LIST_HEAD(&rreq->io_streams[1].subrequests);
 	init_waitqueue_head(&rreq->waitq);
-	refcount_set(&rreq->ref, 1);
+	refcount_set(&rreq->ref, 2);
 
 	if (origin == NETFS_READAHEAD ||
 	    origin == NETFS_READPAGE ||
@@ -63,7 +66,9 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 		INIT_WORK(&rreq->work, netfs_write_collection_worker);
 	}
 
+	/* The IN_PROGRESS flag comes with a ref. */
 	__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
+
 	if (file && file->f_flags & O_NONBLOCK)
 		__set_bit(NETFS_RREQ_NONBLOCK, &rreq->flags);
 	if (rreq->netfs_ops->init_request) {
@@ -75,7 +80,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 	}
 
 	atomic_inc(&ctx->io_count);
-	trace_netfs_rreq_ref(rreq->debug_id, 1, netfs_rreq_trace_new);
+	trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), netfs_rreq_trace_new);
 	netfs_proc_add_rreq(rreq);
 	netfs_stat(&netfs_n_rh_rreq);
 	return rreq;
@@ -89,7 +94,7 @@ void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace
 	trace_netfs_rreq_ref(rreq->debug_id, r + 1, what);
 }
 
-void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
+void netfs_clear_subrequests(struct netfs_io_request *rreq)
 {
 	struct netfs_io_subrequest *subreq;
 	struct netfs_io_stream *stream;
@@ -101,8 +106,7 @@ void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async)
 			subreq = list_first_entry(&stream->subrequests,
 						  struct netfs_io_subrequest, rreq_link);
 			list_del(&subreq->rreq_link);
-			netfs_put_subrequest(subreq, was_async,
-					     netfs_sreq_trace_put_clear);
+			netfs_put_subrequest(subreq, netfs_sreq_trace_put_clear);
 		}
 	}
 }
@@ -118,13 +122,19 @@ static void netfs_free_request_rcu(struct rcu_head *rcu)
 static void netfs_free_request(struct work_struct *work)
 {
 	struct netfs_io_request *rreq =
-		container_of(work, struct netfs_io_request, work);
+		container_of(work, struct netfs_io_request, cleanup_work);
 	struct netfs_inode *ictx = netfs_inode(rreq->inode);
 	unsigned int i;
 
 	trace_netfs_rreq(rreq, netfs_rreq_trace_free);
+
+	/* Cancel/flush the result collection worker.  That does not carry a
+	 * ref of its own, so we must wait for it somewhere.
+	 */
+	cancel_work_sync(&rreq->work);
+
 	netfs_proc_del_rreq(rreq);
-	netfs_clear_subrequests(rreq, false);
+	netfs_clear_subrequests(rreq);
 	if (rreq->netfs_ops->free_request)
 		rreq->netfs_ops->free_request(rreq);
 	if (rreq->cache_resources.ops)
@@ -145,8 +155,7 @@ static void netfs_free_request(struct work_struct *work)
 	call_rcu(&rreq->rcu, netfs_free_request_rcu);
 }
 
-void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
-		       enum netfs_rreq_ref_trace what)
+void netfs_put_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what)
 {
 	unsigned int debug_id;
 	bool dead;
@@ -156,15 +165,8 @@ void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
 		debug_id = rreq->debug_id;
 		dead = __refcount_dec_and_test(&rreq->ref, &r);
 		trace_netfs_rreq_ref(debug_id, r - 1, what);
-		if (dead) {
-			if (was_async) {
-				rreq->work.func = netfs_free_request;
-				if (!queue_work(system_unbound_wq, &rreq->work))
-					WARN_ON(1);
-			} else {
-				netfs_free_request(&rreq->work);
-			}
-		}
+		if (dead)
+			WARN_ON(!queue_work(system_unbound_wq, &rreq->cleanup_work));
 	}
 }
 
@@ -206,8 +208,7 @@ void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
 			     what);
 }
 
-static void netfs_free_subrequest(struct netfs_io_subrequest *subreq,
-				  bool was_async)
+static void netfs_free_subrequest(struct netfs_io_subrequest *subreq)
 {
 	struct netfs_io_request *rreq = subreq->rreq;
 
@@ -216,10 +217,10 @@ static void netfs_free_subrequest(struct netfs_io_subrequest *subreq,
 		rreq->netfs_ops->free_subrequest(subreq);
 	mempool_free(subreq, rreq->netfs_ops->subrequest_pool ?: &netfs_subrequest_pool);
 	netfs_stat_d(&netfs_n_rh_sreq);
-	netfs_put_request(rreq, was_async, netfs_rreq_trace_put_subreq);
+	netfs_put_request(rreq, netfs_rreq_trace_put_subreq);
 }
 
-void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async,
+void netfs_put_subrequest(struct netfs_io_subrequest *subreq,
 			  enum netfs_sreq_ref_trace what)
 {
 	unsigned int debug_index = subreq->debug_index;
@@ -230,5 +231,5 @@ void netfs_put_subrequest(struct netfs_io_subrequest *subreq, bool was_async,
 	dead = __refcount_dec_and_test(&subreq->ref, &r);
 	trace_netfs_sreq_ref(debug_id, debug_index, r - 1, what);
 	if (dead)
-		netfs_free_subrequest(subreq, was_async);
+		netfs_free_subrequest(subreq);
 }
diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c
index d3cf27b2697c3..1197ebce56757 100644
--- a/fs/netfs/read_collect.c
+++ b/fs/netfs/read_collect.c
@@ -301,7 +301,7 @@ reassess:
 						 struct netfs_io_subrequest, rreq_link);
 		stream->front = front;
 		spin_unlock(&rreq->lock);
-		netfs_put_subrequest(remove, false,
+		netfs_put_subrequest(remove,
 				     notes & ABANDON_SREQ ?
 				     netfs_sreq_trace_put_abandon :
 				     netfs_sreq_trace_put_done);
@@ -399,7 +399,7 @@ static void netfs_rreq_assess_single(struct netfs_io_request *rreq)
  * Note that we're in normal kernel thread context at this point, possibly
  * running on a workqueue.
  */
-static void netfs_read_collection(struct netfs_io_request *rreq)
+static bool netfs_read_collection(struct netfs_io_request *rreq)
 {
 	struct netfs_io_stream *stream = &rreq->io_streams[0];
 
@@ -409,11 +409,11 @@ static void netfs_read_collection(struct netfs_io_request *rreq)
 	 * queue is empty.
 	 */
 	if (!test_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags))
-		return;
+		return false;
 	smp_rmb(); /* Read ALL_QUEUED before subreq lists. */
 
 	if (!list_empty(&stream->subrequests))
-		return;
+		return false;
 
 	/* Okay, declare that all I/O is complete. */
 	rreq->transferred = stream->transferred;
@@ -436,12 +436,14 @@ static void netfs_read_collection(struct netfs_io_request *rreq)
 
 	trace_netfs_rreq(rreq, netfs_rreq_trace_wake_ip);
 	clear_and_wake_up_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
+	/* As we cleared NETFS_RREQ_IN_PROGRESS, we acquired its ref. */
 
 	trace_netfs_rreq(rreq, netfs_rreq_trace_done);
-	netfs_clear_subrequests(rreq, false);
+	netfs_clear_subrequests(rreq);
 	netfs_unlock_abandoned_read_pages(rreq);
 	if (unlikely(rreq->copy_to_cache))
 		netfs_pgpriv2_end_copy_to_cache(rreq);
+	return true;
 }
 
 void netfs_read_collection_worker(struct work_struct *work)
@@ -449,9 +451,13 @@ void netfs_read_collection_worker(struct work_struct *work)
 	struct netfs_io_request *rreq = container_of(work, struct netfs_io_request, work);
 
 	netfs_see_request(rreq, netfs_rreq_trace_see_work);
-	if (test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags))
-		netfs_read_collection(rreq);
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_work);
+	if (test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags)) {
+		if (netfs_read_collection(rreq))
+			/* Drop the ref from the IN_PROGRESS flag. */
+			netfs_put_request(rreq, netfs_rreq_trace_put_work_ip);
+		else
+			netfs_see_request(rreq, netfs_rreq_trace_see_work_complete);
+	}
 }
 
 /*
@@ -461,11 +467,7 @@ void netfs_wake_read_collector(struct netfs_io_request *rreq)
 {
 	if (test_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags) &&
 	    !test_bit(NETFS_RREQ_RETRYING, &rreq->flags)) {
-		if (!work_pending(&rreq->work)) {
-			netfs_get_request(rreq, netfs_rreq_trace_get_work);
-			if (!queue_work(system_unbound_wq, &rreq->work))
-				netfs_put_request(rreq, true, netfs_rreq_trace_put_work_nq);
-		}
+		queue_work(system_unbound_wq, &rreq->work);
 	} else {
 		trace_netfs_rreq(rreq, netfs_rreq_trace_wake_queue);
 		wake_up(&rreq->waitq);
@@ -580,14 +582,14 @@ void netfs_read_subreq_terminated(struct netfs_io_subrequest *subreq)
 	    test_bit(NETFS_RREQ_RETRYING, &rreq->flags))
 		netfs_wake_read_collector(rreq);
 
-	netfs_put_subrequest(subreq, true, netfs_sreq_trace_put_terminated);
+	netfs_put_subrequest(subreq, netfs_sreq_trace_put_terminated);
 }
 EXPORT_SYMBOL(netfs_read_subreq_terminated);
 
 /*
  * Handle termination of a read from the cache.
  */
-void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error, bool was_async)
+void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error)
 {
 	struct netfs_io_subrequest *subreq = priv;
 
@@ -623,7 +625,11 @@ ssize_t netfs_wait_for_read(struct netfs_io_request *rreq)
 		    (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags) ||
 		     test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags))) {
 			__set_current_state(TASK_RUNNING);
-			netfs_read_collection(rreq);
+			if (netfs_read_collection(rreq)) {
+				/* Drop the ref from the NETFS_RREQ_IN_PROGRESS flag. */
+				netfs_put_request(rreq, netfs_rreq_trace_put_work_ip);
+				break;
+			}
 			continue;
 		}
 
@@ -678,7 +684,11 @@ void netfs_wait_for_pause(struct netfs_io_request *rreq)
 			    (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags) ||
 			     test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags))) {
 				__set_current_state(TASK_RUNNING);
-				netfs_read_collection(rreq);
+				if (netfs_read_collection(rreq)) {
+					/* Drop the ref from the NETFS_RREQ_IN_PROGRESS flag. */
+					netfs_put_request(rreq, netfs_rreq_trace_put_work_ip);
+					break;
+				}
 				continue;
 			}
 		}
diff --git a/fs/netfs/read_pgpriv2.c b/fs/netfs/read_pgpriv2.c
index cf7727060215a..5bbe906a551d5 100644
--- a/fs/netfs/read_pgpriv2.c
+++ b/fs/netfs/read_pgpriv2.c
@@ -116,7 +116,7 @@ static struct netfs_io_request *netfs_pgpriv2_begin_copy_to_cache(
 	return creq;
 
 cancel_put:
-	netfs_put_request(creq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(creq, netfs_rreq_trace_put_return);
 cancel:
 	rreq->copy_to_cache = ERR_PTR(-ENOBUFS);
 	clear_bit(NETFS_RREQ_FOLIO_COPY_TO_CACHE, &rreq->flags);
@@ -155,7 +155,7 @@ void netfs_pgpriv2_end_copy_to_cache(struct netfs_io_request *rreq)
 	smp_wmb(); /* Write lists before ALL_QUEUED. */
 	set_bit(NETFS_RREQ_ALL_QUEUED, &creq->flags);
 
-	netfs_put_request(creq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(creq, netfs_rreq_trace_put_return);
 	creq->copy_to_cache = NULL;
 }
 
diff --git a/fs/netfs/read_retry.c b/fs/netfs/read_retry.c
index 0f294b26e08c9..1378dc7fa2ccd 100644
--- a/fs/netfs/read_retry.c
+++ b/fs/netfs/read_retry.c
@@ -173,7 +173,7 @@ static void netfs_retry_read_subrequests(struct netfs_io_request *rreq)
 						      &stream->subrequests, rreq_link) {
 				trace_netfs_sreq(subreq, netfs_sreq_trace_superfluous);
 				list_del(&subreq->rreq_link);
-				netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_done);
+				netfs_put_subrequest(subreq, netfs_sreq_trace_put_done);
 				if (subreq == to)
 					break;
 			}
diff --git a/fs/netfs/read_single.c b/fs/netfs/read_single.c
index fea0ecdecc539..fa622a6cd56da 100644
--- a/fs/netfs/read_single.c
+++ b/fs/netfs/read_single.c
@@ -142,7 +142,7 @@ static int netfs_single_dispatch_read(struct netfs_io_request *rreq)
 	set_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags);
 	return ret;
 cancel:
-	netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_cancel);
+	netfs_put_subrequest(subreq, netfs_sreq_trace_put_cancel);
 	return ret;
 }
 
@@ -185,11 +185,11 @@ ssize_t netfs_read_single(struct inode *inode, struct file *file, struct iov_ite
 	netfs_single_dispatch_read(rreq);
 
 	ret = netfs_wait_for_read(rreq);
-	netfs_put_request(rreq, true, netfs_rreq_trace_put_return);
+	netfs_put_request(rreq, netfs_rreq_trace_put_return);
 	return ret;
 
 cleanup_free:
-	netfs_put_request(rreq, false, netfs_rreq_trace_put_failed);
+	netfs_put_request(rreq, netfs_rreq_trace_put_failed);
 	return ret;
 }
 EXPORT_SYMBOL(netfs_read_single);
diff --git a/fs/netfs/write_collect.c b/fs/netfs/write_collect.c
index 3fca59e6475d1..7241d1fd2c14a 100644
--- a/fs/netfs/write_collect.c
+++ b/fs/netfs/write_collect.c
@@ -280,7 +280,7 @@ reassess_streams:
 							 struct netfs_io_subrequest, rreq_link);
 			stream->front = front;
 			spin_unlock(&wreq->lock);
-			netfs_put_subrequest(remove, false,
+			netfs_put_subrequest(remove,
 					     notes & SAW_FAILURE ?
 					     netfs_sreq_trace_put_cancel :
 					     netfs_sreq_trace_put_done);
@@ -356,30 +356,21 @@ need_retry:
 /*
  * Perform the collection of subrequests, folios and encryption buffers.
  */
-void netfs_write_collection_worker(struct work_struct *work)
+static bool netfs_write_collection(struct netfs_io_request *wreq)
 {
-	struct netfs_io_request *wreq = container_of(work, struct netfs_io_request, work);
 	struct netfs_inode *ictx = netfs_inode(wreq->inode);
 	size_t transferred;
 	int s;
 
 	_enter("R=%x", wreq->debug_id);
 
-	netfs_see_request(wreq, netfs_rreq_trace_see_work);
-	if (!test_bit(NETFS_RREQ_IN_PROGRESS, &wreq->flags)) {
-		netfs_put_request(wreq, false, netfs_rreq_trace_put_work);
-		return;
-	}
-
 	netfs_collect_write_results(wreq);
 
 	/* We're done when the app thread has finished posting subreqs and all
 	 * the queues in all the streams are empty.
 	 */
-	if (!test_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags)) {
-		netfs_put_request(wreq, false, netfs_rreq_trace_put_work);
-		return;
-	}
+	if (!test_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags))
+		return false;
 	smp_rmb(); /* Read ALL_QUEUED before lists. */
 
 	transferred = LONG_MAX;
@@ -387,10 +378,8 @@ void netfs_write_collection_worker(struct work_struct *work)
 		struct netfs_io_stream *stream = &wreq->io_streams[s];
 		if (!stream->active)
 			continue;
-		if (!list_empty(&stream->subrequests)) {
-			netfs_put_request(wreq, false, netfs_rreq_trace_put_work);
-			return;
-		}
+		if (!list_empty(&stream->subrequests))
+			return false;
 		if (stream->transferred < transferred)
 			transferred = stream->transferred;
 	}
@@ -430,6 +419,7 @@ void netfs_write_collection_worker(struct work_struct *work)
 	_debug("finished");
 	trace_netfs_rreq(wreq, netfs_rreq_trace_wake_ip);
 	clear_and_wake_up_bit(NETFS_RREQ_IN_PROGRESS, &wreq->flags);
+	/* As we cleared NETFS_RREQ_IN_PROGRESS, we acquired its ref. */
 
 	if (wreq->iocb) {
 		size_t written = min(wreq->transferred, wreq->len);
@@ -440,27 +430,36 @@ void netfs_write_collection_worker(struct work_struct *work)
 		wreq->iocb = VFS_PTR_POISON;
 	}
 
-	netfs_clear_subrequests(wreq, false);
-	netfs_put_request(wreq, false, netfs_rreq_trace_put_work_complete);
+	netfs_clear_subrequests(wreq);
+	return true;
+}
+
+void netfs_write_collection_worker(struct work_struct *work)
+{
+	struct netfs_io_request *rreq = container_of(work, struct netfs_io_request, work);
+
+	netfs_see_request(rreq, netfs_rreq_trace_see_work);
+	if (test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags)) {
+		if (netfs_write_collection(rreq))
+			/* Drop the ref from the IN_PROGRESS flag. */
+			netfs_put_request(rreq, netfs_rreq_trace_put_work_ip);
+		else
+			netfs_see_request(rreq, netfs_rreq_trace_see_work_complete);
+	}
 }
 
 /*
  * Wake the collection work item.
  */
-void netfs_wake_write_collector(struct netfs_io_request *wreq, bool was_async)
+void netfs_wake_write_collector(struct netfs_io_request *wreq)
 {
-	if (!work_pending(&wreq->work)) {
-		netfs_get_request(wreq, netfs_rreq_trace_get_work);
-		if (!queue_work(system_unbound_wq, &wreq->work))
-			netfs_put_request(wreq, was_async, netfs_rreq_trace_put_work_nq);
-	}
+	queue_work(system_unbound_wq, &wreq->work);
 }
 
 /**
  * netfs_write_subrequest_terminated - Note the termination of a write operation.
  * @_op: The I/O request that has terminated.
  * @transferred_or_error: The amount of data transferred or an error code.
- * @was_async: The termination was asynchronous
  *
  * This tells the library that a contributory write I/O operation has
  * terminated, one way or another, and that it should collect the results.
@@ -470,17 +469,13 @@ void netfs_wake_write_collector(struct netfs_io_request *wreq, bool was_async)
  * negative error code.  The library will look after reissuing I/O operations
  * as appropriate and writing downloaded data to the cache.
  *
- * If @was_async is true, the caller might be running in softirq or interrupt
- * context and we can't sleep.
- *
  * When this is called, ownership of the subrequest is transferred back to the
  * library, along with a ref.
  *
  * Note that %_op is a void* so that the function can be passed to
  * kiocb::term_func without the need for a casting wrapper.
  */
-void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error,
-				       bool was_async)
+void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error)
 {
 	struct netfs_io_subrequest *subreq = _op;
 	struct netfs_io_request *wreq = subreq->rreq;
@@ -543,8 +538,8 @@ void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error,
 	 * transferring a ref to it if we were the ones to do so.
 	 */
 	if (list_is_first(&subreq->rreq_link, &stream->subrequests))
-		netfs_wake_write_collector(wreq, was_async);
+		netfs_wake_write_collector(wreq);
 
-	netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
+	netfs_put_subrequest(subreq, netfs_sreq_trace_put_terminated);
 }
 EXPORT_SYMBOL(netfs_write_subrequest_terminated);
diff --git a/fs/netfs/write_issue.c b/fs/netfs/write_issue.c
index 77279fc5b5a7c..8744ed3faf29b 100644
--- a/fs/netfs/write_issue.c
+++ b/fs/netfs/write_issue.c
@@ -134,7 +134,7 @@ struct netfs_io_request *netfs_create_write_req(struct address_space *mapping,
 	return wreq;
 nomem:
 	wreq->error = -ENOMEM;
-	netfs_put_request(wreq, false, netfs_rreq_trace_put_failed);
+	netfs_put_request(wreq, netfs_rreq_trace_put_failed);
 	return ERR_PTR(-ENOMEM);
 }
 
@@ -233,7 +233,7 @@ static void netfs_do_issue_write(struct netfs_io_stream *stream,
 	_enter("R=%x[%x],%zx", wreq->debug_id, subreq->debug_index, subreq->len);
 
 	if (test_bit(NETFS_SREQ_FAILED, &subreq->flags))
-		return netfs_write_subrequest_terminated(subreq, subreq->error, false);
+		return netfs_write_subrequest_terminated(subreq, subreq->error);
 
 	trace_netfs_sreq(subreq, netfs_sreq_trace_submit);
 	stream->issue_write(subreq);
@@ -542,7 +542,7 @@ static void netfs_end_issue_write(struct netfs_io_request *wreq)
 	}
 
 	if (needs_poke)
-		netfs_wake_write_collector(wreq, false);
+		netfs_wake_write_collector(wreq);
 }
 
 /*
@@ -599,8 +599,9 @@ int netfs_writepages(struct address_space *mapping,
 	netfs_end_issue_write(wreq);
 
 	mutex_unlock(&ictx->wb_lock);
+	netfs_wake_write_collector(wreq);
 
-	netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(wreq, netfs_rreq_trace_put_return);
 	_leave(" = %d", error);
 	return error;
 
@@ -694,7 +695,7 @@ int netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_contr
 		wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS, TASK_UNINTERRUPTIBLE);
 		ret = wreq->error;
 	}
-	netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(wreq, netfs_rreq_trace_put_return);
 	return ret;
 }
 
@@ -885,7 +886,7 @@ int netfs_writeback_single(struct address_space *mapping,
 		goto couldnt_start;
 	}
 
-	trace_netfs_write(wreq, netfs_write_trace_writeback);
+	trace_netfs_write(wreq, netfs_write_trace_writeback_single);
 	netfs_stat(&netfs_n_wh_writepages);
 
 	if (__test_and_set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags))
@@ -914,8 +915,9 @@ stop:
 	set_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags);
 
 	mutex_unlock(&ictx->wb_lock);
+	netfs_wake_write_collector(wreq);
 
-	netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
+	netfs_put_request(wreq, netfs_rreq_trace_put_return);
 	_leave(" = %d", ret);
 	return ret;
 
diff --git a/fs/netfs/write_retry.c b/fs/netfs/write_retry.c
index 9b1ca8b0f4dd6..7408f6bb8e42e 100644
--- a/fs/netfs/write_retry.c
+++ b/fs/netfs/write_retry.c
@@ -132,7 +132,7 @@ static void netfs_retry_write_stream(struct netfs_io_request *wreq,
 						      &stream->subrequests, rreq_link) {
 				trace_netfs_sreq(subreq, netfs_sreq_trace_discard);
 				list_del(&subreq->rreq_link);
-				netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_done);
+				netfs_put_subrequest(subreq, netfs_sreq_trace_put_done);
 				if (subreq == to)
 					break;
 			}