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From: David Howells <dhowells@redhat.com>
To: Christian Brauner <christian@brauner.io>,
	Jeff Layton <jlayton@kernel.org>,
	Gao Xiang <hsiangkao@linux.alibaba.com>,
	Dominique Martinet <asmadeus@codewreck.org>
Cc: David Howells <dhowells@redhat.com>,
	Matthew Wilcox <willy@infradead.org>,
	Steve French <smfrench@gmail.com>,
	Marc Dionne <marc.dionne@auristor.com>,
	Paulo Alcantara <pc@manguebit.com>,
	Shyam Prasad N <sprasad@microsoft.com>,
	Tom Talpey <tom@talpey.com>,
	Eric Van Hensbergen <ericvh@kernel.org>,
	Ilya Dryomov <idryomov@gmail.com>,
	netfs@lists.linux.dev,
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Subject: [PATCH v2 05/22] netfs: Make netfs_io_request::subreq_counter an atomic_t
Date: Tue, 30 Apr 2024 15:00:36 +0100
Message-ID: <20240430140056.261997-6-dhowells@redhat.com>
In-Reply-To: <20240430140056.261997-1-dhowells@redhat.com>
References: <20240430140056.261997-1-dhowells@redhat.com>
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Make the netfs_io_request::subreq_counter, used to generate values for
netfs_io_subrequest::debug_index, into an atomic_t so that it can be called
from the retry thread at the same time as the app thread issuing writes.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
---
 fs/netfs/output.c     | 2 +-
 include/linux/netfs.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/netfs/output.c b/fs/netfs/output.c
index 625eb68f3e5a..fbdbb4f78234 100644
--- a/fs/netfs/output.c
+++ b/fs/netfs/output.c
@@ -37,7 +37,7 @@ struct netfs_io_subrequest *netfs_create_write_request(struct netfs_io_request *
 		subreq->source	= dest;
 		subreq->start	= start;
 		subreq->len	= len;
-		subreq->debug_index = wreq->subreq_counter++;
+		subreq->debug_index = atomic_inc_return(&wreq->subreq_counter);
 
 		switch (subreq->source) {
 		case NETFS_UPLOAD_TO_SERVER:
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index f36a6d8163d1..ddafc6ebff42 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -202,7 +202,7 @@ struct netfs_io_request {
 	unsigned int		debug_id;
 	unsigned int		rsize;		/* Maximum read size (0 for none) */
 	unsigned int		wsize;		/* Maximum write size (0 for none) */
-	unsigned int		subreq_counter;	/* Next subreq->debug_index */
+	atomic_t		subreq_counter;	/* Next subreq->debug_index */
 	atomic_t		nr_outstanding;	/* Number of ops in progress */
 	atomic_t		nr_copy_ops;	/* Number of copy-to-cache ops in progress */
 	size_t			submitted;	/* Amount submitted for I/O so far */