[RFC PATCH v3 05/16] fscrypt: make fscrypt_fname_disk_to_usr return whether result is nokey name

Jeff Layton
2020-09-14T19:17:39Z

Ceph will sometimes need to know whether the resulting name from this
function is a nokey name, in order to set the dentry flags without
racy checks on the parent inode.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/crypto/fname.c | 5 ++++-
fs/crypto/hooks.c | 4 ++--
fs/ext4/dir.c | 3 ++-
fs/ext4/namei.c | 6 ++++--
fs/f2fs/dir.c | 3 ++-
fs/ubifs/dir.c | 4 +++-
include/linux/fscrypt.h | 4 ++--
7 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 0d41eb4a5493..b97a81ccd838 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -353,6 +353,7 @@ EXPORT_SYMBOL(fscrypt_encode_nokey_name);
* @oname: output buffer for the user-presentable filename. The caller must
* have allocated enough space for this, e.g. using
* fscrypt_fname_alloc_buffer().
+ * @is_nokey: set to true if oname is a no-key name
*
* If the key is available, we'll decrypt the disk name. Otherwise, we'll
* encode it for presentation in fscrypt_nokey_name format.
@@ -363,7 +364,8 @@ EXPORT_SYMBOL(fscrypt_encode_nokey_name);
int fscrypt_fname_disk_to_usr(const struct inode *inode,
u32 hash, u32 minor_hash,
const struct fscrypt_str *iname,
- struct fscrypt_str *oname)
+ struct fscrypt_str *oname,
+ bool *is_nokey)
{
const struct qstr qname = FSTR_TO_QSTR(iname);
struct fscrypt_nokey_name nokey_name;
@@ -411,6 +413,7 @@ int fscrypt_fname_disk_to_usr(const struct inode *inode,
size = FSCRYPT_NOKEY_NAME_MAX;
}
oname->len = fscrypt_base64_encode((const u8 *)&nokey_name, size, oname->name);
+ *is_nokey = true;
return 0;
}
EXPORT_SYMBOL(fscrypt_fname_disk_to_usr);
diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
index 42f5ee9f592d..cdad06b4e521 100644
--- a/fs/crypto/hooks.c
+++ b/fs/crypto/hooks.c
@@ -310,7 +310,7 @@ const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
{
const struct fscrypt_symlink_data *sd;
struct fscrypt_str cstr, pstr;
- bool has_key;
+ bool has_key, is_nokey = false;
int err;

/* This is for encrypted symlinks only */
@@ -352,7 +352,7 @@ const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
if (err)
return ERR_PTR(err);

- err = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
+ err = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr, &is_nokey);
if (err)
goto err_kfree;

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index efe77cffc322..ac6b04bebcf6 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -260,6 +260,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
get_dtype(sb, de->file_type)))
goto done;
} else {
+ bool is_nokey = false;
int save_len = fstr.len;
struct fscrypt_str de_name =
FSTR_INIT(de->name,
@@ -267,7 +268,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)

/* Directory is encrypted */
err = fscrypt_fname_disk_to_usr(inode,
- 0, 0, &de_name, &fstr);
+ 0, 0, &de_name, &fstr, &is_nokey);
de_name = fstr;
fstr.len = save_len;
if (err)
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 0d74615fcce3..3ba407833be5 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -658,6 +658,7 @@ static struct stats dx_show_leaf(struct inode *dir,
(unsigned) ((char *) de
- base));
} else {
+ bool is_nokey = false;
struct fscrypt_str de_name =
FSTR_INIT(name, len);

@@ -671,7 +672,7 @@ static struct stats dx_show_leaf(struct inode *dir,
"crypto\n");
res = fscrypt_fname_disk_to_usr(dir,
0, 0, &de_name,
- &fname_crypto_str);
+ &fname_crypto_str, &is_nokey);
if (res) {
printk(KERN_WARNING "Error "
"converting filename "
@@ -1045,6 +1046,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
hinfo->hash, hinfo->minor_hash, de,
&tmp_str);
} else {
+ bool is_nokey = false;
int save_len = fname_crypto_str.len;
struct fscrypt_str de_name = FSTR_INIT(de->name,
de->name_len);
@@ -1052,7 +1054,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
/* Directory is encrypted */
err = fscrypt_fname_disk_to_usr(dir, hinfo->hash,
hinfo->minor_hash, &de_name,
- &fname_crypto_str);
+ &fname_crypto_str, &is_nokey);
if (err) {
count = err;
goto errout;
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 414bc94fbd54..d235e40210cf 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -985,11 +985,12 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
}

if (IS_ENCRYPTED(d->inode)) {
+ bool is_nokey = false;
int save_len = fstr->len;

err = fscrypt_fname_disk_to_usr(d->inode,
(u32)le32_to_cpu(de->hash_code),
- 0, &de_name, fstr);
+ 0, &de_name, fstr, &is_nokey);
if (err)
goto out;

diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 155521e51ac5..da1a4bc861d5 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -584,12 +584,14 @@ static int ubifs_readdir(struct file *file, struct dir_context *ctx)
fname_name(&nm) = dent->name;

if (encrypted) {
+ bool is_nokey = false;
+
fstr.len = fstr_real_len;

err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c,
&dent->key),
le32_to_cpu(dent->cookie),
- &nm.disk_name, &fstr);
+ &nm.disk_name, &fstr, &is_nokey);
if (err)
goto out;
} else {
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index a57d2a9869eb..bae18aa4173a 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -201,7 +201,7 @@ void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str);
int fscrypt_fname_disk_to_usr(const struct inode *inode,
u32 hash, u32 minor_hash,
const struct fscrypt_str *iname,
- struct fscrypt_str *oname);
+ struct fscrypt_str *oname, bool *is_nokey);
bool fscrypt_match_name(const struct fscrypt_name *fname,
const u8 *de_name, u32 de_name_len);
u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name);
@@ -442,7 +442,7 @@ static inline void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str)
static inline int fscrypt_fname_disk_to_usr(const struct inode *inode,
u32 hash, u32 minor_hash,
const struct fscrypt_str *iname,
- struct fscrypt_str *oname)
+ struct fscrypt_str *oname, bool *is_nokey)
{
return -EOPNOTSUPP;
}
--
2.26.2