FAILED: patch "[PATCH] cifs: Fix non-availability of dedup breaking generic/304" failed to apply to 5.4-stable tree

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 691a41d8da4b34fe72f09393505f55f28a8f34ec
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023121111-grieving-paced-f285@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

691a41d8da4b ("cifs: Fix non-availability of dedup breaking generic/304")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 691a41d8da4b34fe72f09393505f55f28a8f34ec Mon Sep 17 00:00:00 2001
From: David Howells <[email protected]>
Date: Mon, 4 Dec 2023 14:01:59 +0000
Subject: [PATCH] cifs: Fix non-availability of dedup breaking generic/304

Deduplication isn't supported on cifs, but cifs doesn't reject it, instead treating it as extent duplication/cloning. This can cause generic/304 to go silly and run for hours on end.

Fix cifs to indicate EOPNOTSUPP if REMAP_FILE_DEDUP is set in ->remap_file_range().

Note that it's unclear whether or not commit b073a08016a1 is meant to cause cifs to return an error if REMAP_FILE_DEDUP.

index c5fc0a35bb19..2131638f26d0 100644
@@ -1277,7 +1277,9 @@ static loff_t cifs_remap_file_range(struct file *src_file, loff_t off,
 	unsigned int xid;
 	int rc;
 
-	if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
+	if (remap_flags & REMAP_FILE_DEDUP)
+		return -EOPNOTSUPP;
+	if (remap_flags & ~REMAP_FILE_ADVISORY)
 		return -EINVAL;
 
 	cifs_dbg(FYI, "clone range\n");