[PATCH v9 4/4] ext4: Use generic casefolding support

Daniel Rosenberg
2020-06-24T04:34:18Z

This switches ext4 over to the generic support provided in
commit 5f829feca774 ("fs: Add standard casefolding support")

Signed-off-by: Daniel Rosenberg <drosen@google.com>
---
fs/ext4/dir.c | 64 ++-----------------------------------------------
fs/ext4/ext4.h | 12 ----------
fs/ext4/hash.c | 2 +-
fs/ext4/namei.c | 20 +++++++---------
fs/ext4/super.c | 12 +++++-----
5 files changed, 17 insertions(+), 93 deletions(-)

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 1d82336b1cd45..b437120f0b3f5 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -669,68 +669,8 @@ const struct file_operations ext4_dir_operations = {
};

#ifdef CONFIG_UNICODE
-static int ext4_d_compare(const struct dentry *dentry, unsigned int len,
- const char *str, const struct qstr *name)
-{
- struct qstr qstr = {.name = str, .len = len };
- const struct dentry *parent = READ_ONCE(dentry->d_parent);
- const struct inode *inode = READ_ONCE(parent->d_inode);
- char strbuf[DNAME_INLINE_LEN];
-
- if (!inode || !IS_CASEFOLDED(inode) ||
- !EXT4_SB(inode->i_sb)->s_encoding) {
- if (len != name->len)
- return -1;
- return memcmp(str, name->name, len);
- }
-
- /*
- * If the dentry name is stored in-line, then it may be concurrently
- * modified by a rename. If this happens, the VFS will eventually retry
- * the lookup, so it doesn't matter what ->d_compare() returns.
- * However, it's unsafe to call utf8_strncasecmp() with an unstable
- * string. Therefore, we have to copy the name into a temporary buffer.
- */
- if (len <= DNAME_INLINE_LEN - 1) {
- memcpy(strbuf, str, len);
- strbuf[len] = 0;
- qstr.name = strbuf;
- /* prevent compiler from optimizing out the temporary buffer */
- barrier();
- }
-
- return ext4_ci_compare(inode, name, &qstr, false);
-}
-
-static int ext4_d_hash(const struct dentry *dentry, struct qstr *str)
-{
- const struct ext4_sb_info *sbi = EXT4_SB(dentry->d_sb);
- const struct unicode_map *um = sbi->s_encoding;
- const struct inode *inode = READ_ONCE(dentry->d_inode);
- unsigned char *norm;
- int len, ret = 0;
-
- if (!inode || !IS_CASEFOLDED(inode) || !um)
- return 0;
-
- norm = kmalloc(PATH_MAX, GFP_ATOMIC);
- if (!norm)
- return -ENOMEM;
-
- len = utf8_casefold(um, str, norm, PATH_MAX);
- if (len < 0) {
- if (ext4_has_strict_mode(sbi))
- ret = -EINVAL;
- goto out;
- }
- str->hash = full_name_hash(dentry, norm, len);
-out:
- kfree(norm);
- return ret;
-}
-
const struct dentry_operations ext4_dentry_ops = {
- .d_hash = ext4_d_hash,
- .d_compare = ext4_d_compare,
+ .d_hash = generic_ci_d_hash,
+ .d_compare = generic_ci_d_compare,
};
#endif
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 42f5060f3cdf1..5cd8be24a4fd9 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1393,14 +1393,6 @@ struct ext4_super_block {

#define EXT4_ENC_UTF8_12_1 1

-/*
- * Flags for ext4_sb_info.s_encoding_flags.
- */
-#define EXT4_ENC_STRICT_MODE_FL (1 << 0)
-
-#define ext4_has_strict_mode(sbi) \
- (sbi->s_encoding_flags & EXT4_ENC_STRICT_MODE_FL)
-
/*
* fourth extended-fs super-block data in memory
*/
@@ -1450,10 +1442,6 @@ struct ext4_sb_info {
struct kobject s_kobj;
struct completion s_kobj_unregister;
struct super_block *s_sb;
-#ifdef CONFIG_UNICODE
- struct unicode_map *s_encoding;
- __u16 s_encoding_flags;
-#endif

/* Journaling */
struct journal_s *s_journal;
diff --git a/fs/ext4/hash.c b/fs/ext4/hash.c
index 3e133793a5a34..143b0073b3f46 100644
--- a/fs/ext4/hash.c
+++ b/fs/ext4/hash.c
@@ -275,7 +275,7 @@ int ext4fs_dirhash(const struct inode *dir, const char *name, int len,
struct dx_hash_info *hinfo)
{
#ifdef CONFIG_UNICODE
- const struct unicode_map *um = EXT4_SB(dir->i_sb)->s_encoding;
+ const struct unicode_map *um = dir->i_sb->s_encoding;
int r, dlen;
unsigned char *buff;
struct qstr qstr = {.name = name, .len = len };
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 56738b538ddf4..7e9fb77fd2cc7 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1286,8 +1286,8 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
const struct qstr *entry, bool quick)
{
- const struct ext4_sb_info *sbi = EXT4_SB(parent->i_sb);
- const struct unicode_map *um = sbi->s_encoding;
+ const struct super_block *sb = parent->i_sb;
+ const struct unicode_map *um = sb->s_encoding;
int ret;

if (quick)
@@ -1299,7 +1299,7 @@ int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
/* Handle invalid character sequence as either an error
* or as an opaque byte sequence.
*/
- if (ext4_has_strict_mode(sbi))
+ if (sb_has_enc_strict_mode(sb))
return -EINVAL;

if (name->len != entry->len)
@@ -1316,7 +1316,7 @@ void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
{
int len;

- if (!IS_CASEFOLDED(dir) || !EXT4_SB(dir->i_sb)->s_encoding) {
+ if (!needs_casefold(dir)) {
cf_name->name = NULL;
return;
}
@@ -1325,7 +1325,7 @@ void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
if (!cf_name->name)
return;

- len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding,
+ len = utf8_casefold(dir->i_sb->s_encoding,
iname, cf_name->name,
EXT4_NAME_LEN);
if (len <= 0) {
@@ -1362,7 +1362,7 @@ static inline bool ext4_match(const struct inode *parent,
#endif

#ifdef CONFIG_UNICODE
- if (EXT4_SB(parent->i_sb)->s_encoding && IS_CASEFOLDED(parent)) {
+ if (needs_casefold(parent)) {
if (fname->cf_name.name) {
struct qstr cf = {.name = fname->cf_name.name,
.len = fname->cf_name.len};
@@ -2171,9 +2171,6 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
struct buffer_head *bh = NULL;
struct ext4_dir_entry_2 *de;
struct super_block *sb;
-#ifdef CONFIG_UNICODE
- struct ext4_sb_info *sbi;
-#endif
struct ext4_filename fname;
int retval;
int dx_fallback=0;
@@ -2190,9 +2187,8 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
return -EINVAL;

#ifdef CONFIG_UNICODE
- sbi = EXT4_SB(sb);
- if (ext4_has_strict_mode(sbi) && IS_CASEFOLDED(dir) &&
- sbi->s_encoding && utf8_validate(sbi->s_encoding, &dentry->d_name))
+ if (sb_has_enc_strict_mode(sb) && IS_CASEFOLDED(dir) &&
+ sb->s_encoding && utf8_validate(sb->s_encoding, &dentry->d_name))
return -EINVAL;
#endif

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 330957ed1f05c..d097771a374f8 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1102,7 +1102,7 @@ static void ext4_put_super(struct super_block *sb)
fs_put_dax(sbi->s_daxdev);
fscrypt_free_dummy_context(&sbi->s_dummy_enc_ctx);
#ifdef CONFIG_UNICODE
- utf8_unload(sbi->s_encoding);
+ utf8_unload(sb->s_encoding);
#endif
kfree(sbi);
}
@@ -4035,7 +4035,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
goto failed_mount;

#ifdef CONFIG_UNICODE
- if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
+ if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {
const struct ext4_sb_encodings *encoding_info;
struct unicode_map *encoding;
__u16 encoding_flags;
@@ -4066,8 +4066,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
"%s-%s with flags 0x%hx", encoding_info->name,
encoding_info->version?:"\b", encoding_flags);

- sbi->s_encoding = encoding;
- sbi->s_encoding_flags = encoding_flags;
+ sb->s_encoding = encoding;
+ sb->s_encoding_flags = encoding_flags;
}
#endif

@@ -4678,7 +4678,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
}

#ifdef CONFIG_UNICODE
- if (sbi->s_encoding)
+ if (sb->s_encoding)
sb->s_d_op = &ext4_dentry_ops;
#endif

@@ -4873,7 +4873,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
crypto_free_shash(sbi->s_chksum_driver);

#ifdef CONFIG_UNICODE
- utf8_unload(sbi->s_encoding);
+ utf8_unload(sb->s_encoding);
#endif

#ifdef CONFIG_QUOTA
--
2.27.0.111.gc72c7da667-goog