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From:   "Guilherme G. Piccoli" <gpiccoli@igalia.com>
To:     linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc:     kernel-dev@igalia.com, kernel@gpiccoli.net, keescook@chromium.org,
        anton@enomsg.org, ccross@android.com, tony.luck@intel.com,
        "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Subject: [PATCH 1/8] pstore: Improve error reporting in case of backend overlap
Date:   Thu,  6 Oct 2022 19:42:05 -0300
Message-Id: <20221006224212.569555-2-gpiccoli@igalia.com>
In-Reply-To: <20221006224212.569555-1-gpiccoli@igalia.com>
References: <20221006224212.569555-1-gpiccoli@igalia.com>
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The pstore infrastructure supports one single backend at a time;
trying to load a another backend causes an error and displays a
message, introduced on commit 0d7cd09a3dbb ("pstore: Improve
register_pstore() error reporting").

Happens that this message is not really clear about the situation,
also the current error returned (-EPERM) isn't accurate, whereas
-EBUSY makes more sense. We have another place in the code that
relies in the -EBUSY return for a similar check.

So, make it consistent here by returning -EBUSY and using a
similar message in both scenarios.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
---
 fs/pstore/platform.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 0c034ea39954..c32957e4b256 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -562,8 +562,9 @@ static int pstore_write_user_compat(struct pstore_record *record,
 int pstore_register(struct pstore_info *psi)
 {
 	if (backend && strcmp(backend, psi->name)) {
-		pr_warn("ignoring unexpected backend '%s'\n", psi->name);
-		return -EPERM;
+		pr_warn("backend '%s' already in use: ignoring '%s'\n",
+			backend, psi->name);
+		return -EBUSY;
 	}
 
 	/* Sanity check flags. */
-- 
2.38.0