[PATCH v7 02/10] fscrypt: Factor out a helper to configure the lookup dentry

Gabriel Krisman Bertazi
2024-02-21T17:14:23Z

Both fscrypt_prepare_lookup_partial and fscrypt_prepare_lookup will set
DCACHE_NOKEY_NAME for dentries when the key is not available. Extract
out a helper to set this flag in a single place, in preparation to also
add the optimization that will disable ->d_revalidate if possible.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>

---
changes since v7
- Fix function names in commit message (Eric)
- Have a stub for the CONFIG_FS_ENCRYPTION=n case (Eric)
changes since v6
- Use inline comparison for is_nokey_name (eric)
- rename fscrypt_prepare_lookup_dentry->fscrypt_prepare_dentry (eric)
---
fs/crypto/hooks.c | 15 +++++----------
include/linux/fscrypt.h | 15 +++++++++++++++
2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
index 52504dd478d3..104771c3d3f6 100644
--- a/fs/crypto/hooks.c
+++ b/fs/crypto/hooks.c
@@ -102,11 +102,8 @@ int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry,
if (err && err != -ENOENT)
return err;

- if (fname->is_nokey_name) {
- spin_lock(&dentry->d_lock);
- dentry->d_flags |= DCACHE_NOKEY_NAME;
- spin_unlock(&dentry->d_lock);
- }
+ fscrypt_prepare_dentry(dentry, fname->is_nokey_name);
+
return err;
}
EXPORT_SYMBOL_GPL(__fscrypt_prepare_lookup);
@@ -131,12 +128,10 @@ EXPORT_SYMBOL_GPL(__fscrypt_prepare_lookup);
int fscrypt_prepare_lookup_partial(struct inode *dir, struct dentry *dentry)
{
int err = fscrypt_get_encryption_info(dir, true);
+ bool is_nokey_name = (!err && !fscrypt_has_encryption_key(dir));
+
+ fscrypt_prepare_dentry(dentry, is_nokey_name);

- if (!err && !fscrypt_has_encryption_key(dir)) {
- spin_lock(&dentry->d_lock);
- dentry->d_flags |= DCACHE_NOKEY_NAME;
- spin_unlock(&dentry->d_lock);
- }
return err;
}
EXPORT_SYMBOL_GPL(fscrypt_prepare_lookup_partial);
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 12f9e455d569..c76f859cf019 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -261,6 +261,16 @@ static inline bool fscrypt_is_nokey_name(const struct dentry *dentry)
return dentry->d_flags & DCACHE_NOKEY_NAME;
}

+static inline void fscrypt_prepare_dentry(struct dentry *dentry,
+ bool is_nokey_name)
+{
+ if (is_nokey_name) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_NOKEY_NAME;
+ spin_unlock(&dentry->d_lock);
+ }
+}
+
/* crypto.c */
void fscrypt_enqueue_decrypt_work(struct work_struct *);

@@ -425,6 +435,11 @@ static inline bool fscrypt_is_nokey_name(const struct dentry *dentry)
return false;
}

+static inline void fscrypt_prepare_dentry(struct dentry *dentry,
+ bool is_nokey_name)
+{
+}
+
/* crypto.c */
static inline void fscrypt_enqueue_decrypt_work(struct work_struct *work)
{
--
2.43.0