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From: Chao Yu <chao@kernel.org>
To: jaegeuk@kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net,
	linux-kernel@vger.kernel.org,
	Chao Yu <chao@kernel.org>
Subject: [PATCH] f2fs: compress: fix to check zstd compress level correctly in mount option
Date: Tue, 13 Feb 2024 00:08:18 +0800
Message-Id: <20240212160818.1020903-1-chao@kernel.org>
Precedence: bulk
MIME-Version: 1.0
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f2fs only support to config zstd compress level w/ a positive number due
to layout design, but since commit e0c1b49f5b67 ("lib: zstd: Upgrade to
latest upstream zstd version 1.4.10"), zstd supports negative compress
level, so that zstd_min_clevel() may return a negative number, then w/
below mount option, .compress_level can be configed w/ a negative number,
which is not allowed to f2fs, let's add check condition to avoid it.

mount -o compress_algorithm=zstd:4294967295 /dev/sdx /mnt/f2fs

Fixes: 00e120b5e4b5 ("f2fs: assign default compression level")
Signed-off-by: Chao Yu <chao@kernel.org>
---
 fs/f2fs/super.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 1b718bebfaa1..a29b8e25a2ed 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -669,7 +669,7 @@ static int f2fs_set_lz4hc_level(struct f2fs_sb_info *sbi, const char *str)
 #ifdef CONFIG_F2FS_FS_ZSTD
 static int f2fs_set_zstd_level(struct f2fs_sb_info *sbi, const char *str)
 {
-	unsigned int level;
+	int level;
 	int len = 4;
 
 	if (strlen(str) == len) {
@@ -683,9 +683,15 @@ static int f2fs_set_zstd_level(struct f2fs_sb_info *sbi, const char *str)
 		f2fs_info(sbi, "wrong format, e.g. <alg_name>:<compr_level>");
 		return -EINVAL;
 	}
-	if (kstrtouint(str + 1, 10, &level))
+	if (kstrtoint(str + 1, 10, &level))
 		return -EINVAL;
 
+	/* f2fs does not support negative compress level now */
+	if (level < 0) {
+		f2fs_info(sbi, "do not support negative compress level: %d", level);
+		return -ERANGE;
+	}
+
 	if (!f2fs_is_compress_level_valid(COMPRESS_ZSTD, level)) {
 		f2fs_info(sbi, "invalid zstd compress level: %d", level);
 		return -EINVAL;
-- 
2.40.1