Matching names with casefolded encrypting directories requires
decrypting entries to confirm case since we are case preserving. We can
avoid needing to decrypt if our hash values don't match.
Signed-off-by: Daniel Rosenberg
---
fs/ext4/ext4.h | 17 ---
fs/ext4/namei.c | 55 ++---
2 files changed, 38 insertions(+), 34 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index dafa528c4d9f..181d07791efb 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2637,9 +2637,9 @@ extern unsigned ext4_free_clusters_after_init(struct
super_block *sb,
ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
#ifdef CONFIG_UNICODE
-extern void ext4_fname_setup_ci_filename(struct inode *dir,
+extern int ext4_fname_setup_ci_filename(struct inode *dir,
const struct qstr *iname,
-struct fscrypt_str *fname);
+struct ext4_filename *fname);
#endif
#ifdef CONFIG_FS_ENCRYPTION
@@ -2670,9 +2670,9 @@ static inline int ext4_fname_setup_filename(struct inode
*dir,
ext4_fname_from_fscrypt_name(fname, );
#ifdef CONFIG_UNICODE
- ext4_fname_setup_ci_filename(dir, iname, >cf_name);
+ err = ext4_fname_setup_ci_filename(dir, iname, fname);
#endif
- return 0;
+ return err;
}
static inline int ext4_fname_prepare_lookup(struct inode *dir,
@@ -2689,9 +2689,9 @@ static inline int ext4_fname_prepare_lookup(struct inode
*dir,
ext4_fname_from_fscrypt_name(fname, );
#ifdef CONFIG_UNICODE
- ext4_fname_setup_ci_filename(dir, >d_name, >cf_name);
+ err = ext4_fname_setup_ci_filename(dir, >d_name, fname);
#endif
- return 0;
+ return err;
}
static inline void ext4_fname_free_filename(struct ext4_filename *fname)
@@ -2716,15 +2716,16 @@ static inline int ext4_fname_setup_filename(struct
inode *dir,
int lookup,
struct ext4_filename *fname)
{
+ int err = 0;
fname->usr_fname = iname;
fname->disk_name.name = (unsigned char *) iname->name;
fname->disk_name.len = iname->len;
#ifdef CONFIG_UNICODE
- ext4_fname_setup_ci_filename(dir, iname, >cf_name);
+ err = ext4_fname_setup_ci_filename(dir, iname, fname);
#endif
- return 0;
+ return err;
}
static inline int ext4_fname_prepare_lookup(struct inode *dir,
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 97d2755b9775..1fb7128220ce 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -816,7 +816,9 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
if (hinfo->hash_version <= DX_HASH_TEA)
hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
- if (fname && fname_name(fname))
+ /* hash is already computed for encrypted casefolded directory */
+ if (fname && fname_name(fname) &&
+ !(IS_ENCRYPTED(dir) && IS_CASEFOLDED(dir)))
ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo);
hash = hinfo->hash;
@@ -1367,19 +1369,21 @@ static int ext4_ci_compare(const struct inode *parent,
const struct qstr *name,
return ret;
}
-void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
- struct fscrypt_str *cf_name)
+int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
+ struct ext4_filename *name)
{
+ struct fscrypt_str *cf_name = >cf_name;
+ struct dx_hash_info *hinfo = >hinfo;
int len;
if (!IS_CASEFOLDED(dir) || !dir->i_sb->s_encoding) {
cf_name->name = NULL;
- return;
+ return 0;
}
cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
if (!cf_name->name)
- return;
+ return -ENOMEM;
len = utf8_casefold(dir->i_sb->s_encoding,
iname, cf_name->name,
@@ -1387,10 +1391,18 @@ void ext4_fname_setup_ci_filename(struct inode *dir,
const struct qstr *iname,
if (len <= 0) {
kfree(cf_name->name);
cf_name->name = NULL;
- return;
}
cf_name->len = (unsigned) len;
+ if (!IS_ENCRYPTED(dir))
+ return 0;
+ hinfo->hash_version = DX_HASH_SIPHASH;
+ hinfo->seed = NULL;
+ if (cf_name->name)
+ ext4fs_dirhash(dir, cf_name->name, cf_name->len, hinfo);
+ else
+ ext4fs_dirhash(dir, iname->name, iname->len, hinfo);
+ return 0;
}
#endif
@@ -1420,16 +1432,12 @@ static bool ext4_match(struct inode *parent,
struct qstr cf = {.name = fname->cf_name.name,
.len =
