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

From: Eugen Hristev
Date: Wed May 29 2024 - 04:34:10 EST


From: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>

Keeping it as qstr avoids the unnecessary conversion in ext4_match

Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
[eugen.hristev@xxxxxxxxxxxxx: port to 6.10-rc1]
Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
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