f2fs: compress: fix to avoid redundant compress extension

[ Upstream commit 7e1b150 ] With below script, redundant compress extension will be parsed and added by parse_options(), because parse_options() doesn't check whether the extension is existed or not, fix it. 1. mount -t f2fs -o compress_extension=so /dev/vdb /mnt/f2fs 2. mount -t f2fs -o remount,compress_extension=so /mnt/f2fs 3. mount|grep f2fs /dev/vdb on /mnt/f2fs type f2fs (...,compress_extension=so,compress_extension=so,...) Fixes: 4c8ff70 ("f2fs: support data compression") Fixes: 151b198 ("f2fs: compress: add nocompress extensions support") Signed-off-by: Chao Yu <[email protected]> Signed-off-by: Jaegeuk Kim <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
tobetter · Nov 20, 2023 · e9f598a · e9f598a
1 parent 8c4504c
commit e9f598a
Showing 1 changed file with 33 additions and 0 deletions.
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
@@ -540,6 +540,29 @@ static int f2fs_set_test_dummy_encryption(struct super_block *sb,
 }
 
 #ifdef CONFIG_F2FS_FS_COMPRESSION
+static bool is_compress_extension_exist(struct f2fs_sb_info *sbi,
+					const char *new_ext, bool is_ext)
+{
+	unsigned char (*ext)[F2FS_EXTENSION_LEN];
+	int ext_cnt;
+	int i;
+
+	if (is_ext) {
+		ext = F2FS_OPTION(sbi).extensions;
+		ext_cnt = F2FS_OPTION(sbi).compress_ext_cnt;
+	} else {
+		ext = F2FS_OPTION(sbi).noextensions;
+		ext_cnt = F2FS_OPTION(sbi).nocompress_ext_cnt;
+	}
+
+	for (i = 0; i < ext_cnt; i++) {
+		if (!strcasecmp(new_ext, ext[i]))
+			return true;
+	}
+
+	return false;
+}
+
 /*
  * 1. The same extension name cannot not appear in both compress and non-compress extension
  * at the same time.
@@ -1154,6 +1177,11 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 				return -EINVAL;
 			}
 
+			if (is_compress_extension_exist(sbi, name, true)) {
+				kfree(name);
+				break;
+			}
+
 			strcpy(ext[ext_cnt], name);
 			F2FS_OPTION(sbi).compress_ext_cnt++;
 			kfree(name);
@@ -1178,6 +1206,11 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 				return -EINVAL;
 			}
 
+			if (is_compress_extension_exist(sbi, name, false)) {
+				kfree(name);
+				break;
+			}
+
 			strcpy(noext[noext_cnt], name);
 			F2FS_OPTION(sbi).nocompress_ext_cnt++;
 			kfree(name);