linux-kernel - [PATCH v17 1/7] ext4: Simplify the handling of cached casefolded names

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Message-Id: <20240529082634.141286-2-eugen.hristev@collabora.com>
Date: Wed, 29 May 2024 11:26:28 +0300
From: Eugen Hristev <eugen.hristev@...labora.com>
To: linux-ext4@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-f2fs-devel@...ts.sourceforge.net,
	linux-fsdevel@...r.kernel.org,
	jaegeuk@...nel.org,
	adilger.kernel@...ger.ca,
	tytso@....edu
Cc: chao@...nel.org,
	viro@...iv.linux.org.uk,
	brauner@...nel.org,
	jack@...e.cz,
	ebiggers@...gle.com,
	krisman@...e.de,
	kernel@...labora.com,
	Gabriel Krisman Bertazi <krisman@...labora.com>,
	Eugen Hristev <eugen.hristev@...labora.com>
Subject: [PATCH v17 1/7] ext4: Simplify the handling of cached casefolded names

From: Gabriel Krisman Bertazi <krisman@...labora.com>

Keeping it as qstr avoids the unnecessary conversion in ext4_match

Signed-off-by: Gabriel Krisman Bertazi <krisman@...labora.com>
[eugen.hristev@...labora.com: port to 6.10-rc1]
Signed-off-by: Eugen Hristev <eugen.hristev@...labora.com>
Reviewed-by: Eric Biggers <ebiggers@...gle.com>
---
 fs/ext4/ext4.h  |  2 +-
 fs/ext4/namei.c | 23 +++++++++++------------
 2 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 983dad8c07ec..deffd7431c8b 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2511,7 +2511,7 @@ struct ext4_filename {
 	struct fscrypt_str crypto_buf;
 #endif
 #if IS_ENABLED(CONFIG_UNICODE)
-	struct fscrypt_str cf_name;
+	struct qstr cf_name;
 #endif
 };
 
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a630b27a4cc6..ec4c9bfc1057 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1445,7 +1445,8 @@ static int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
 int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
 				  struct ext4_filename *name)
 {
-	struct fscrypt_str *cf_name = &name->cf_name;
+	struct qstr *cf_name = &name->cf_name;
+	unsigned char *buf;
 	struct dx_hash_info *hinfo = &name->hinfo;
 	int len;
 
@@ -1455,18 +1456,18 @@ int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
 		return 0;
 	}
 
-	cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
-	if (!cf_name->name)
+	buf = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
+	if (!buf)
 		return -ENOMEM;
 
-	len = utf8_casefold(dir->i_sb->s_encoding,
-			    iname, cf_name->name,
-			    EXT4_NAME_LEN);
+	len = utf8_casefold(dir->i_sb->s_encoding, iname, buf, EXT4_NAME_LEN);
 	if (len <= 0) {
-		kfree(cf_name->name);
-		cf_name->name = NULL;
+		kfree(buf);
+		buf = NULL;
 	}
+	cf_name->name = buf;
 	cf_name->len = (unsigned) len;
+
 	if (!IS_ENCRYPTED(dir))
 		return 0;
 
@@ -1503,8 +1504,6 @@ static bool ext4_match(struct inode *parent,
 	if (IS_CASEFOLDED(parent) &&
 	    (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) {
 		if (fname->cf_name.name) {
-			struct qstr cf = {.name = fname->cf_name.name,
-					  .len = fname->cf_name.len};
 			if (IS_ENCRYPTED(parent)) {
 				if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
 					fname->hinfo.minor_hash !=
@@ -1513,8 +1512,8 @@ static bool ext4_match(struct inode *parent,
 					return false;
 				}
 			}
-			return !ext4_ci_compare(parent, &cf, de->name,
-							de->name_len, true);
+			return !ext4_ci_compare(parent, &fname->cf_name,
+						de->name, de->name_len, true);
 		}
 		return !ext4_ci_compare(parent, fname->usr_fname, de->name,
 						de->name_len, false);
-- 
2.34.1