f2fs: compress: add nocompress extensions support

When we create a directory with enable compression, all file write into
directory will try to compress.But sometimes we may know, new file
cannot meet compression ratio requirements.
We need a nocompress extension to skip those files to avoid unnecessary
compress page test.

After add nocompress_extension, the priority should be:
dir_flag < comp_extention,nocompress_extension < comp_file_flag,
no_comp_file_flag.

Priority in between FS_COMPR_FL, FS_NOCOMP_FS, extensions:
   * compress_extension=so; nocompress_extension=zip; chattr +c dir;
     touch dir/foo.so; touch dir/bar.zip; touch dir/baz.txt; then foo.so
     and baz.txt should be compresse, bar.zip should be non-compressed.
     chattr +c dir/bar.zip can enable compress on bar.zip.
   * compress_extension=so; nocompress_extension=zip; chattr -c dir;
     touch dir/foo.so; touch dir/bar.zip; touch dir/baz.txt; then foo.so
     should be compresse, bar.zip and baz.txt should be non-compressed.
     chattr+c dir/bar.zip; chattr+c dir/baz.txt; can enable compress on
     bar.zip and baz.txt.

Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 78 insertions, 1 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 289cdda3d17b..8fecd3050ccd 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -148,6 +148,7 @@ enum {
 	Opt_compress_algorithm,
 	Opt_compress_log_size,
 	Opt_compress_extension,
+	Opt_nocompress_extension,
 	Opt_compress_chksum,
 	Opt_compress_mode,
 	Opt_compress_cache,
@@ -223,6 +224,7 @@ static match_table_t f2fs_tokens = {
 	{Opt_compress_algorithm, "compress_algorithm=%s"},
 	{Opt_compress_log_size, "compress_log_size=%u"},
 	{Opt_compress_extension, "compress_extension=%s"},
+	{Opt_nocompress_extension, "nocompress_extension=%s"},
 	{Opt_compress_chksum, "compress_chksum"},
 	{Opt_compress_mode, "compress_mode=%s"},
 	{Opt_compress_cache, "compress_cache"},
@@ -493,6 +495,43 @@ static int f2fs_set_test_dummy_encryption(struct super_block *sb,
 }
 
 #ifdef CONFIG_F2FS_FS_COMPRESSION
+/*
+ * 1. The same extension name cannot not appear in both compress and non-compress extension
+ * at the same time.
+ * 2. If the compress extension specifies all files, the types specified by the non-compress
+ * extension will be treated as special cases and will not be compressed.
+ * 3. Don't allow the non-compress extension specifies all files.
+ */
+static int f2fs_test_compress_extension(struct f2fs_sb_info *sbi)
+{
+	unsigned char (*ext)[F2FS_EXTENSION_LEN];
+	unsigned char (*noext)[F2FS_EXTENSION_LEN];
+	int ext_cnt, noext_cnt, index = 0, no_index = 0;
+
+	ext = F2FS_OPTION(sbi).extensions;
+	ext_cnt = F2FS_OPTION(sbi).compress_ext_cnt;
+	noext = F2FS_OPTION(sbi).noextensions;
+	noext_cnt = F2FS_OPTION(sbi).nocompress_ext_cnt;
+
+	if (!noext_cnt)
+		return 0;
+
+	for (no_index = 0; no_index < noext_cnt; no_index++) {
+		if (!strcasecmp("*", noext[no_index])) {
+			f2fs_info(sbi, "Don't allow the nocompress extension specifies all files");
+			return -EINVAL;
+		}
+		for (index = 0; index < ext_cnt; index++) {
+			if (!strcasecmp(ext[index], noext[no_index])) {
+				f2fs_info(sbi, "Don't allow the same extension %s appear in both compress and nocompress extension",
+						ext[index]);
+				return -EINVAL;
+			}
+		}
+	}
+	return 0;
+}
+
 #ifdef CONFIG_F2FS_FS_LZ4
 static int f2fs_set_lz4hc_level(struct f2fs_sb_info *sbi, const char *str)
 {
@@ -566,7 +605,8 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 	substring_t args[MAX_OPT_ARGS];
 #ifdef CONFIG_F2FS_FS_COMPRESSION
 	unsigned char (*ext)[F2FS_EXTENSION_LEN];
-	int ext_cnt;
+	unsigned char (*noext)[F2FS_EXTENSION_LEN];
+	int ext_cnt, noext_cnt;
 #endif
 	char *p, *name;
 	int arg = 0;
@@ -1069,6 +1109,30 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 			F2FS_OPTION(sbi).compress_ext_cnt++;
 			kfree(name);
 			break;
+		case Opt_nocompress_extension:
+			if (!f2fs_sb_has_compression(sbi)) {
+				f2fs_info(sbi, "Image doesn't support compression");
+				break;
+			}
+			name = match_strdup(&args[0]);
+			if (!name)
+				return -ENOMEM;
+
+			noext = F2FS_OPTION(sbi).noextensions;
+			noext_cnt = F2FS_OPTION(sbi).nocompress_ext_cnt;
+
+			if (strlen(name) >= F2FS_EXTENSION_LEN ||
+				noext_cnt >= COMPRESS_EXT_NUM) {
+				f2fs_err(sbi,
+					"invalid extension length/number");
+				kfree(name);
+				return -EINVAL;
+			}
+
+			strcpy(noext[noext_cnt], name);
+			F2FS_OPTION(sbi).nocompress_ext_cnt++;
+			kfree(name);
+			break;
 		case Opt_compress_chksum:
 			F2FS_OPTION(sbi).compress_chksum = true;
 			break;
@@ -1093,6 +1157,7 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
 		case Opt_compress_algorithm:
 		case Opt_compress_log_size:
 		case Opt_compress_extension:
+		case Opt_nocompress_extension:
 		case Opt_compress_chksum:
 		case Opt_compress_mode:
 		case Opt_compress_cache:
@@ -1147,6 +1212,13 @@ default_check:
 	}
 #endif
 
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+	if (f2fs_test_compress_extension(sbi)) {
+		f2fs_err(sbi, "invalid compress or nocompress extension");
+		return -EINVAL;
+	}
+#endif
+
 	if (F2FS_IO_SIZE_BITS(sbi) && !f2fs_lfs_mode(sbi)) {
 		f2fs_err(sbi, "Should set mode=lfs with %uKB-sized IO",
 			 F2FS_IO_SIZE_KB(sbi));
@@ -1697,6 +1769,11 @@ static inline void f2fs_show_compress_options(struct seq_file *seq,
 			F2FS_OPTION(sbi).extensions[i]);
 	}
 
+	for (i = 0; i < F2FS_OPTION(sbi).nocompress_ext_cnt; i++) {
+		seq_printf(seq, ",nocompress_extension=%s",
+			F2FS_OPTION(sbi).noextensions[i]);
+	}
+
 	if (F2FS_OPTION(sbi).compress_chksum)
 		seq_puts(seq, ",compress_chksum");