Merge tag 'vfs-6.10-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:

 - Fix io_uring based write-through after converting cifs to use the
   netfs library

 - Fix aio error handling when doing write-through via netfs library

 - Fix performance regression in iomap when used with non-large folio
   mappings

 - Fix signalfd error code

 - Remove obsolete comment in signalfd code

 - Fix async request indication in netfs_perform_write() by raising
   BDP_ASYNC when IOCB_NOWAIT is set

 - Yield swap device immediately to prevent spurious EBUSY errors

 - Don't cross a .backup mountpoint from backup volumes in afs to avoid
   infinite loops

 - Fix a race between umount and async request completion in 9p after 9p
   was converted to use the netfs library

* tag 'vfs-6.10-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  netfs, 9p: Fix race between umount and async request completion
  afs: Don't cross .backup mountpoint from backup volume
  swap: yield device immediately
  netfs: Fix setting of BDP_ASYNC from iocb flags
  signalfd: drop an obsolete comment
  signalfd: fix error return code
  iomap: fault in smaller chunks for non-large folio mappings
  filemap: add helper mapping_max_folio_size()
  netfs: Fix AIO error handling when doing write-through
  netfs: Fix io_uring based write-through

5 files changed, 18 insertions, 7 deletions

diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 1121601536d1..07bc1fd43530 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -181,7 +181,7 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
 	struct folio *folio, *writethrough = NULL;
 	enum netfs_how_to_modify howto;
 	enum netfs_folio_trace trace;
-	unsigned int bdp_flags = (iocb->ki_flags & IOCB_SYNC) ? 0: BDP_ASYNC;
+	unsigned int bdp_flags = (iocb->ki_flags & IOCB_NOWAIT) ? BDP_ASYNC : 0;
 	ssize_t written = 0, ret, ret2;
 	loff_t i_size, pos = iocb->ki_pos, from, to;
 	size_t max_chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER;
diff --git a/fs/netfs/direct_write.c b/fs/netfs/direct_write.c
index f516460e994e..e14cd53ac9fd 100644
--- a/fs/netfs/direct_write.c
+++ b/fs/netfs/direct_write.c
@@ -12,7 +12,7 @@
 static void netfs_cleanup_dio_write(struct netfs_io_request *wreq)
 {
 	struct inode *inode = wreq->inode;
-	unsigned long long end = wreq->start + wreq->len;
+	unsigned long long end = wreq->start + wreq->transferred;
 
 	if (!wreq->error &&
 	    i_size_read(inode) < end) {
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index c90d482b1650..f4a642727479 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -72,6 +72,7 @@ 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);
 	netfs_proc_add_rreq(rreq);
 	netfs_stat(&netfs_n_rh_rreq);
@@ -124,6 +125,7 @@ static void netfs_free_request(struct work_struct *work)
 {
 	struct netfs_io_request *rreq =
 		container_of(work, struct netfs_io_request, work);
+	struct netfs_inode *ictx = netfs_inode(rreq->inode);
 	unsigned int i;
 
 	trace_netfs_rreq(rreq, netfs_rreq_trace_free);
@@ -142,6 +144,9 @@ static void netfs_free_request(struct work_struct *work)
 		}
 		kvfree(rreq->direct_bv);
 	}
+
+	if (atomic_dec_and_test(&ictx->io_count))
+		wake_up_var(&ictx->io_count);
 	call_rcu(&rreq->rcu, netfs_free_request_rcu);
 }
 
diff --git a/fs/netfs/write_collect.c b/fs/netfs/write_collect.c
index 60112e4b2c5e..426cf87aaf2e 100644
--- a/fs/netfs/write_collect.c
+++ b/fs/netfs/write_collect.c
@@ -510,7 +510,7 @@ reassess_streams:
 	 * stream has a gap that can be jumped.
 	 */
 	if (notes & SOME_EMPTY) {
-		unsigned long long jump_to = wreq->start + wreq->len;
+		unsigned long long jump_to = wreq->start + READ_ONCE(wreq->submitted);
 
 		for (s = 0; s < NR_IO_STREAMS; s++) {
 			stream = &wreq->io_streams[s];
@@ -690,10 +690,11 @@ void netfs_write_collection_worker(struct work_struct *work)
 	wake_up_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS);
 
 	if (wreq->iocb) {
-		wreq->iocb->ki_pos += wreq->transferred;
+		size_t written = min(wreq->transferred, wreq->len);
+		wreq->iocb->ki_pos += written;
 		if (wreq->iocb->ki_complete)
 			wreq->iocb->ki_complete(
-				wreq->iocb, wreq->error ? wreq->error : wreq->transferred);
+				wreq->iocb, wreq->error ? wreq->error : written);
 		wreq->iocb = VFS_PTR_POISON;
 	}
 
diff --git a/fs/netfs/write_issue.c b/fs/netfs/write_issue.c
index e190043bc0da..3aa86e268f40 100644
--- a/fs/netfs/write_issue.c
+++ b/fs/netfs/write_issue.c
@@ -254,7 +254,7 @@ static void netfs_issue_write(struct netfs_io_request *wreq,
 	stream->construct = NULL;
 
 	if (subreq->start + subreq->len > wreq->start + wreq->submitted)
-		wreq->len = wreq->submitted = subreq->start + subreq->len - wreq->start;
+		WRITE_ONCE(wreq->submitted, subreq->start + subreq->len - wreq->start);
 	netfs_do_issue_write(stream, subreq);
 }
 
@@ -636,7 +636,12 @@ int netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_contr
 
 	mutex_unlock(&ictx->wb_lock);
 
-	ret = wreq->error;
+	if (wreq->iocb) {
+		ret = -EIOCBQUEUED;
+	} else {
+		wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS, TASK_UNINTERRUPTIBLE);
+		ret = wreq->error;
+	}
 	netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
 	return ret;
 }