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From: Mateusz Guzik <mjguzik@gmail.com>
To: brauner@kernel.org
Cc: viro@zeniv.linux.org.uk, jack@suse.cz,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Mateusz Guzik <mjguzik@gmail.com>,
	Jeff Layton <jlayton@kernel.org>
Subject: [PATCH v4 1/2] filelock: use a consume fence in locks_inode_context()
Date: Wed,  3 Dec 2025 10:48:36 +0100	[thread overview]
Message-ID: <20251203094837.290654-1-mjguzik@gmail.com> (raw)

Matches the idiom of storing a pointer with a release fence and safely
getting the content with a consume fence after.

Eliminates an actual fence on some archs.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
---
 include/linux/filelock.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/filelock.h b/include/linux/filelock.h
index 54b824c05299..dc15f5427680 100644
--- a/include/linux/filelock.h
+++ b/include/linux/filelock.h
@@ -241,7 +241,10 @@ bool locks_owner_has_blockers(struct file_lock_context *flctx,
 static inline struct file_lock_context *
 locks_inode_context(const struct inode *inode)
 {
-	return smp_load_acquire(&inode->i_flctx);
+	/*
+	 * Paired with the fence in locks_get_lock_context().
+	 */
+	return READ_ONCE(inode->i_flctx);
 }
 
 #else /* !CONFIG_FILE_LOCKING */
-- 
2.48.1


             reply	other threads:[~2025-12-03  9:48 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-12-03  9:48 Mateusz Guzik [this message]
2025-12-03  9:48 ` [PATCH v4 2/2] fs: track the inode having file locks with a flag in ->i_opflags Mateusz Guzik
2025-12-04  9:14 ` [PATCH v4 1/2] filelock: use a consume fence in locks_inode_context() Christian Brauner

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