From: Randall P. Embry <rpembry@gmail.com>
Date: Fri, 26 Sep 2025 09:27:30 +0000 (+0900)
Subject: 9p: fix /sys/fs/9p/caches overwriting itself
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=86db0c32f16c5538ddb740f54669ace8f3a1f3d7;p=users%2Fhch%2Fmisc.git

9p: fix /sys/fs/9p/caches overwriting itself

caches_show() overwrote its buffer on each iteration,
so only the last cache tag was visible in sysfs output.

Properly append with snprintf(buf + count, …).

Signed-off-by: Randall P. Embry <rpembry@gmail.com>
Message-ID: <20250926-v9fs_misc-v1-2-a8b3907fc04d@codewreck.org>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
---

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 01e70a464b60..4d289c56578f 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -560,7 +560,7 @@ static ssize_t caches_show(struct kobject *kobj,
 	spin_lock(&v9fs_sessionlist_lock);
 	list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
 		if (v9ses->cachetag) {
-			n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
+			n = snprintf(buf + count, limit, "%s\n", v9ses->cachetag);
 			if (n < 0) {
 				count = n;
 				break;