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From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Andrew Morton <akpm@linux-foundation.org>,
	Minchan Kim <minchan@kernel.org>
Cc: linux-kernel@vger.kernel.org,
	linux-block@vger.kernel.org,
	Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: [PATCHv4 11/21] zram: extend comp_algorithm attr write handling
Date: Wed, 15 May 2024 16:12:48 +0900
Message-ID: <20240515071645.1788128-12-senozhatsky@chromium.org>
In-Reply-To: <20240515071645.1788128-1-senozhatsky@chromium.org>
References: <20240515071645.1788128-1-senozhatsky@chromium.org>
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Previously comp_algorithm device attr would accept only
algorithm name param, however in order to enabled comp
configuration we need to extend comp_algorithm_store()
with param=value support.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
 drivers/block/zram/zram_drv.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 75ecdb885d91..7eb500c8fdaa 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1013,9 +1013,33 @@ static ssize_t comp_algorithm_store(struct device *dev,
 				    size_t len)
 {
 	struct zram *zram = dev_to_zram(dev);
+	char *args, *param, *val;
+	char *alg = NULL;
 	int ret;
 
-	ret = __comp_algorithm_store(zram, ZRAM_PRIMARY_COMP, buf);
+	args = skip_spaces(buf);
+	while (*args) {
+		args = next_arg(args, &param, &val);
+
+		/*
+		 * We need to support 'param' without value, which is an
+		 * old format for this attr (algorithm name only).
+		 */
+		if (!val || !*val) {
+			alg = param;
+			continue;
+		}
+
+		if (!strcmp(param, "algo")) {
+			alg = val;
+			continue;
+		}
+	}
+
+	if (!alg)
+		return -EINVAL;
+
+	ret = __comp_algorithm_store(zram, ZRAM_PRIMARY_COMP, alg);
 	return ret ? ret : len;
 }
 
-- 
2.45.0.rc1.225.g2a3ae87e7f-goog