fscrypt: Factor out a helper to configure the lookup dentry

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.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240221171412.10710-3-krisman@suse.de
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>

diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
index 52504dd478d31b4b1cd2db9780970e867435f91c..104771c3d3f6ad968ef822c464edfbc7f1b52ca2 100644 (file)
--- 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 12f9e455d569f0a43aade8a9c6bb47402d6139b6..c76f859cf019372cdd675390404f80aff35496d5 100644 (file)
--- 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)
 {