There exists many similar and duplicate codes to check "." and "..",
so introduce is_dot_or_dotdot helper to make the code more clean.
Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
v4:
- rename is_dot_dotdot() to is_dot_or_dotdot()
v3:
- use "name" and "len" as arguments instead of qstr
- move is_dot_dotdot() to include/linux/namei.h
v2:
- use the better performance implementation of is_dot_dotdot
- make it static inline and move it to include/linux/fs.h
fs/crypto/fname.c | 16 +++-------------
fs/ecryptfs/crypto.c | 10 ----------
fs/f2fs/f2fs.h | 11 -----------
fs/f2fs/hash.c | 3 ++-
fs/namei.c | 6 ++----
include/linux/namei.h | 10 ++++++++++
6 files changed, 17 insertions(+), 39 deletions(-)
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 3da3707..ef7eba8 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -11,21 +11,11 @@
* This has not yet undergone a rigorous security audit.
*/
+#include <linux/namei.h>
#include <linux/scatterlist.h>
#include <crypto/skcipher.h>
#include "fscrypt_private.h"
-static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
-{
- if (str->len == 1 && str->name[0] == '.')
- return true;
-
- if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
- return true;
-
- return false;
-}
-
/**
* fname_encrypt() - encrypt a filename
*
@@ -255,7 +245,7 @@ int fscrypt_fname_disk_to_usr(struct inode *inode,
const struct qstr qname = FSTR_TO_QSTR(iname);
struct fscrypt_digested_name digested_name;
- if (fscrypt_is_dot_dotdot(&qname)) {
+ if (is_dot_or_dotdot(qname.name, qname.len)) {
oname->name[0] = '.';
oname->name[iname->len - 1] = '.';
oname->len = iname->len;
@@ -323,7 +313,7 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
memset(fname, 0, sizeof(struct fscrypt_name));
fname->usr_fname = iname;
- if (!IS_ENCRYPTED(dir) || fscrypt_is_dot_dotdot(iname)) {
+ if (!IS_ENCRYPTED(dir) || is_dot_or_dotdot(iname->name, iname->len)) {
fname->disk_name.name = (unsigned char *)iname->name;
fname->disk_name.len = iname->len;
return 0;
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index f91db24..2014f8f 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1991,16 +1991,6 @@ int ecryptfs_encrypt_and_encode_filename(
return rc;
}
-static bool is_dot_dotdot(const char *name, size_t name_size)
-{
- if (name_size == 1 && name[0] == '.')
- return true;
- else if (name_size == 2 && name[0] == '.' && name[1] == '.')
- return true;
-
- return false;
-}
-
/**
* ecryptfs_decode_and_decrypt_filename - converts the encoded cipher text name to decoded plaintext
* @plaintext_name: The plaintext name
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 5a888a0..3d5e684 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2767,17 +2767,6 @@ static inline bool f2fs_cp_error(struct f2fs_sb_info *sbi)
return is_set_ckpt_flags(sbi, CP_ERROR_FLAG);
}
-static inline bool is_dot_dotdot(const struct qstr *str)
-{
- if (str->len == 1 && str->name[0] == '.')
- return true;
-
- if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
- return true;
-
- return false;
-}
-
static inline bool f2fs_may_extent_tree(struct inode *inode)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
diff --git a/fs/f2fs/hash.c b/fs/f2fs/hash.c
index 5bc4dcd..ef155c2 100644
--- a/fs/f2fs/hash.c
+++ b/fs/f2fs/hash.c
@@ -15,6 +15,7 @@
#include <linux/cryptohash.h>
#include <linux/pagemap.h>
#include <linux/unicode.h>
+#include <linux/namei.h>
#include "f2fs.h"
@@ -82,7 +83,7 @@ static f2fs_hash_t __f2fs_dentry_hash(const struct qstr *name_info,
if (fname && !fname->disk_name.name)
return cpu_to_le32(fname->hash);
- if (is_dot_dotdot(name_info))
+ if (is_dot_or_dotdot(name, len))
return 0;
/* Initialize the default seed for the hash checksum functions */
diff --git a/fs/namei.c b/fs/namei.c
index d6c91d1..f3a4439 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2451,10 +2451,8 @@ static int lookup_one_len_common(const char *name, struct dentry *base,
if (!len)
return -EACCES;
- if (unlikely(name[0] == '.')) {
- if (len < 2 || (len == 2 && name[1] == '.'))
- return -EACCES;
- }
+ if (is_dot_or_dotdot(name, len))
+ return -EACCES;
while (len--) {
unsigned int c = *(const unsigned char *)name++;
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 7fe7b87..aba114a 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -92,4 +92,14 @@ retry_estale(const long error, const unsigned int flags)
return error == -ESTALE && !(flags & LOOKUP_REVAL);
}
+static inline bool is_dot_or_dotdot(const unsigned char *name, size_t len)
+{
+ if (unlikely(name[0] == '.')) {
+ if (len < 2 || (len == 2 && name[1] == '.'))
+ return true;
+ }
+
+ return false;
+}
+
#endif /* _LINUX_NAMEI_H */
--
2.1.0
