[PATCH 4/7] libfs: Support revalidation of encrypted case-insensitive dentries

From: Gabriel Krisman Bertazi <krisman@collabora.com>
To: viro@zeniv.linux.org.uk, tytso@mit.edu, jaegeuk@kernel.org
Cc: ebiggers@kernel.org, linux-fsdevel@vger.kernel.org,
	linux-ext4@vger.kernel.org,
	linux-f2fs-devel@lists.sourceforge.net,
	Gabriel Krisman Bertazi <krisman@collabora.com>,
	kernel@collabora.com
Subject: [PATCH 4/7] libfs: Support revalidation of encrypted case-insensitive dentries
Date: Wed, 22 Jun 2022 15:46:00 -0400	[thread overview]
Message-ID: <20220622194603.102655-5-krisman@collabora.com> (raw)
In-Reply-To: <20220622194603.102655-1-krisman@collabora.com>

Preserve the existing behavior for encrypted directories, by rejecting
negative dentries of encrypted+casefolded directories.  This allows
generic_ci_d_revalidate to be used by filesystems with both features
enabled, as long as the directory is either casefolded or encrypted, but
not both at the same time.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
---
 fs/libfs.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/libfs.c b/fs/libfs.c
index de43f3f585f1..e4da68ebd618 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -1461,6 +1461,9 @@ static inline int generic_ci_d_revalidate(struct dentry *dentry,
 		const struct inode *dir = READ_ONCE(parent->d_inode);
 
 		if (dir && needs_casefold(dir)) {
+			if (IS_ENCRYPTED(dir))
+				return 0;
+
 			if (!d_is_casefold_lookup(dentry))
 				return 0;
 
@@ -1470,7 +1473,8 @@ static inline int generic_ci_d_revalidate(struct dentry *dentry,
 				return 0;
 		}
 	}
-	return 1;
+
+	return fscrypt_d_revalidate(dentry, flags);
 }
 
 static const struct dentry_operations generic_ci_dentry_ops = {
@@ -1490,7 +1494,7 @@ static const struct dentry_operations generic_encrypted_dentry_ops = {
 static const struct dentry_operations generic_encrypted_ci_dentry_ops = {
 	.d_hash = generic_ci_d_hash,
 	.d_compare = generic_ci_d_compare,
-	.d_revalidate = fscrypt_d_revalidate,
+	.d_revalidate_name = generic_ci_d_revalidate,
 };
 #endif
 
-- 
2.36.1

