[PATCH resend v2] bcachefs: reject unknown mount options

[David Disseldorp <ddiss@suse.de>]

This is effectively a revert of commit 03ef80b469d5 ("bcachefs: Ignore
unknown mount options"), rebased atop commit 929d954330142 ("bcachefs:
use new mount API").

Contrary to the 03ef80b469d5 commit message, unknown mount options do
result in failure on other filesystems such as xfs, btrfs, ext4, etc.

Ignoring unknown options may result in unexpected behaviour: e.g. if
an application requires future-workload-specific-mount-option to work
and is run on a system without future-workload-specific-mount-option
kernel support, then it may fail without indication of the missing
kernel functionality.

This reversion may cause failures for existing users reliant on the
ignore-unknown behaviour, but it should be bearable given bcachefs is
still flagged experimental.

Fixes: 03ef80b469d5 ("bcachefs: Ignore unknown mount options")
Reported-by: Martin Doucha <martin.doucha@suse.com>
Closes: https://bugzilla.opensuse.org/show_bug.cgi?id=1230065
Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
---
 fs/bcachefs/opts.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/bcachefs/opts.c b/fs/bcachefs/opts.c
index e10fc1da71b19..bc5c180878212 100644
--- a/fs/bcachefs/opts.c
+++ b/fs/bcachefs/opts.c
@@ -482,9 +482,8 @@ int bch2_parse_one_mount_opt(struct bch_fs *c, struct bch_opts *opts,
 		val = "0";
 	}
 
-	/* Unknown options are ignored: */
 	if (id < 0)
-		return 0;
+		goto bad_opt;
 
 	if (!(bch2_opt_table[id].flags & OPT_MOUNT))
 		goto bad_opt;
-- 
2.43.0