[PATCH 5.13 207/351] f2fs: compress: fix to disallow temp extension

Greg Kroah-Hartman
2021-07-19T17:48:35Z

From: Chao Yu <yuchao0@huawei.com>

[ Upstream commit 4a67d9b07ac8dce7f1034e0d887f2f4ee00fe118 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/namei.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index a9cd9cf97229..d4139e166b95 100644
--- 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);
--
2.30.2