f2fs: compress: fix to disallow temp extension

This patch restricts to configure compress extension as format of:

 [filename + '.' + extension]

rather than:

 [filename + '.' + extension + (optional: '.' + temp extension)]

in order to avoid to enable compression incorrectly:

1. compress_extension=so
2. touch file.soa
3. touch file.so.tmp

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index a9cd9cf97229686e48861bcd8007671c2cf3d6b8..d4139e166b958ff161b16d30cd1a558f7d240d7d 100644 (file)
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -153,7 +153,8 @@ fail_drop:
        return ERR_PTR(err);
 }
 
-static inline int is_extension_exist(const unsigned char *s, const char *sub)
+static inline int is_extension_exist(const unsigned char *s, const char *sub,
+                                               bool tmp_ext)
 {
        size_t slen = strlen(s);
        size_t sublen = strlen(sub);
@@ -169,6 +170,13 @@ static inline int is_extension_exist(const unsigned char *s, const char *sub)
        if (slen < sublen + 2)
                return 0;
 
+       if (!tmp_ext) {
+               /* file has no temp extension */
+               if (s[slen - sublen - 1] != '.')
+                       return 0;
+               return !strncasecmp(s + slen - sublen, sub, sublen);
+       }
+
        for (i = 1; i < slen - sublen; i++) {
                if (s[i] != '.')
                        continue;
@@ -194,7 +202,7 @@ static inline void set_file_temperature(struct f2fs_sb_info *sbi, struct inode *
        hot_count = sbi->raw_super->hot_ext_count;
 
        for (i = 0; i < cold_count + hot_count; i++) {
-               if (is_extension_exist(name, extlist[i]))
+               if (is_extension_exist(name, extlist[i], true))
                        break;
        }
 
@@ -295,7 +303,7 @@ static void set_compress_inode(struct f2fs_sb_info *sbi, struct inode *inode,
        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])) {
+               if (is_extension_exist(name, extlist[i], false)) {
                        up_read(&sbi->sb_lock);
                        return;
                }
@@ -306,7 +314,7 @@ static void set_compress_inode(struct f2fs_sb_info *sbi, struct inode *inode,
        ext = F2FS_OPTION(sbi).extensions;
 
        for (i = 0; i < ext_cnt; i++) {
-               if (!is_extension_exist(name, ext[i]))
+               if (!is_extension_exist(name, ext[i], false))
                        continue;
 
                set_compress_context(inode);