f2fs: compress tmp files given extension

Let's compress tmp files for the given extension list.

This patch does not change the previous behavior, but allow the cases as below.

Extention example: "ext"

- abc.ext : allow
- abc.ext.abc : allow
- abc.extm : not allow

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/namei.c

@@ -23,7 +23,7 @@
 #include <trace/events/f2fs.h>
 
 static inline bool is_extension_exist(const unsigned char *s, const char *sub,
-						bool tmp_ext)
+						bool tmp_ext, bool tmp_dot)
 {
 	size_t slen = strlen(s);
 	size_t sublen = strlen(sub);
@@ -49,13 +49,27 @@ static inline bool is_extension_exist(const unsigned char *s, const char *sub,
 	for (i = 1; i < slen - sublen; i++) {
 		if (s[i] != '.')
 			continue;
-		if (!strncasecmp(s + i + 1, sub, sublen))
-			return true;
+		if (!strncasecmp(s + i + 1, sub, sublen)) {
+			if (!tmp_dot)
+				return true;
+			if (i == slen - sublen - 1 || s[i + 1 + sublen] == '.')
+				return true;
+		}
 	}
 
 	return false;
 }
 
+static inline bool is_temperature_extension(const unsigned char *s, const char *sub)
+{
+	return is_extension_exist(s, sub, true, false);
+}
+
+static inline bool is_compress_extension(const unsigned char *s, const char *sub)
+{
+	return is_extension_exist(s, sub, true, true);
+}
+
 int f2fs_update_extension_list(struct f2fs_sb_info *sbi, const char *name,
 							bool hot, bool set)
 {
@@ -148,20 +162,20 @@ static void set_compress_new_inode(struct f2fs_sb_info *sbi, struct inode *dir,
 	cold_count = le32_to_cpu(sbi->raw_super->extension_count);
 	hot_count = sbi->raw_super->hot_ext_count;
 	for (i = cold_count; i < cold_count + hot_count; i++)
-		if (is_extension_exist(name, extlist[i], false))
+		if (is_temperature_extension(name, extlist[i]))
 			break;
 	f2fs_up_read(&sbi->sb_lock);
 	if (i < (cold_count + hot_count))
 		return;
 
 	/* Don't compress unallowed extension. */
 	for (i = 0; i < noext_cnt; i++)
-		if (is_extension_exist(name, noext[i], false))
+		if (is_compress_extension(name, noext[i]))
 			return;
 
 	/* Compress wanting extension. */
 	for (i = 0; i < ext_cnt; i++) {
-		if (is_extension_exist(name, ext[i], false)) {
+		if (is_compress_extension(name, ext[i])) {
 			set_compress_context(inode);
 			return;
 		}
@@ -189,7 +203,7 @@ static void set_file_temperature(struct f2fs_sb_info *sbi, struct inode *inode,
 	cold_count = le32_to_cpu(sbi->raw_super->extension_count);
 	hot_count = sbi->raw_super->hot_ext_count;
 	for (i = 0; i < cold_count + hot_count; i++)
-		if (is_extension_exist(name, extlist[i], true))
+		if (is_temperature_extension(name, extlist[i]))
 			break;
 	f2fs_up_read(&sbi->sb_lock);