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From:   Gabriel Krisman Bertazi <krisman@collabora.com>
To:     tytso@mit.edu, adilger.kernel@dilger.ca, jaegeuk@kernel.org,
        ebiggers@kernel.org
Cc:     linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net,
        Gabriel Krisman Bertazi <krisman@collabora.com>,
        kernel@collabora.com, Eric Biggers <ebiggers@google.com>
Subject: [PATCH v9 2/8] f2fs: Simplify the handling of cached insensitive names
Date:   Tue, 13 Sep 2022 19:41:44 -0400
Message-Id: <20220913234150.513075-3-krisman@collabora.com>
In-Reply-To: <20220913234150.513075-1-krisman@collabora.com>
References: <20220913234150.513075-1-krisman@collabora.com>
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Keeping it as qstr avoids the unnecessary conversion in f2fs_match

Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

---
Changes since v4:
  - Fix inconsistent return on error (eric)
---
 fs/f2fs/dir.c      | 53 ++++++++++++++++++++++++++--------------------
 fs/f2fs/f2fs.h     | 15 ++++++++++++-
 fs/f2fs/recovery.c |  5 +----
 3 files changed, 45 insertions(+), 28 deletions(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index d5bd7932fb64..98db333a1338 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -75,35 +75,49 @@ unsigned char f2fs_get_de_type(struct f2fs_dir_entry *de)
 	return DT_UNKNOWN;
 }
 
+#if IS_ENABLED(CONFIG_UNICODE)
 /* If @dir is casefolded, initialize @fname->cf_name from @fname->usr_fname. */
 int f2fs_init_casefolded_name(const struct inode *dir,
 			      struct f2fs_filename *fname)
 {
-#if IS_ENABLED(CONFIG_UNICODE)
 	struct super_block *sb = dir->i_sb;
+	unsigned char *buf;
+	int len;
 
 	if (IS_CASEFOLDED(dir) &&
 	    !is_dot_dotdot(fname->usr_fname->name, fname->usr_fname->len)) {
-		fname->cf_name.name = f2fs_kmem_cache_alloc(f2fs_cf_name_slab,
-					GFP_NOFS, false, F2FS_SB(sb));
-		if (!fname->cf_name.name)
+		buf = f2fs_kmem_cache_alloc(f2fs_cf_name_slab,
+					    GFP_NOFS, false, F2FS_SB(sb));
+		if (!buf)
 			return -ENOMEM;
-		fname->cf_name.len = utf8_casefold(sb->s_encoding,
-						   fname->usr_fname,
-						   fname->cf_name.name,
-						   F2FS_NAME_LEN);
-		if ((int)fname->cf_name.len <= 0) {
-			kmem_cache_free(f2fs_cf_name_slab, fname->cf_name.name);
-			fname->cf_name.name = NULL;
+
+		len = utf8_casefold(sb->s_encoding, fname->usr_fname,
+				    buf, F2FS_NAME_LEN);
+		if (len <= 0) {
+			kmem_cache_free(f2fs_cf_name_slab, buf);
 			if (sb_has_strict_encoding(sb))
 				return -EINVAL;
 			/* fall back to treating name as opaque byte sequence */
+			return 0;
 		}
+		fname->cf_name.name = buf;
+		fname->cf_name.len = len;
 	}
-#endif
+
 	return 0;
 }
 
+void f2fs_free_casefolded_name(struct f2fs_filename *fname)
+{
+	unsigned char *buf = (unsigned char *)fname->cf_name.name;
+
+	if (buf) {
+		kmem_cache_free(f2fs_cf_name_slab, buf);
+		fname->cf_name.name = NULL;
+	}
+}
+#endif /* CONFIG_UNICODE */
+
 static int __f2fs_setup_filename(const struct inode *dir,
 				 const struct fscrypt_name *crypt_name,
 				 struct f2fs_filename *fname)
@@ -175,12 +189,7 @@ void f2fs_free_filename(struct f2fs_filename *fname)
 	kfree(fname->crypto_buf.name);
 	fname->crypto_buf.name = NULL;
 #endif
-#if IS_ENABLED(CONFIG_UNICODE)
-	if (fname->cf_name.name) {
-		kmem_cache_free(f2fs_cf_name_slab, fname->cf_name.name);
-		fname->cf_name.name = NULL;
-	}
-#endif
+	f2fs_free_casefolded_name(fname);
 }
 
 static unsigned long dir_block_index(unsigned int level,
@@ -268,11 +277,9 @@ static inline int f2fs_match_name(const struct inode *dir,
 	struct fscrypt_name f;
 
 #if IS_ENABLED(CONFIG_UNICODE)
-	if (fname->cf_name.name) {
-		struct qstr cf = FSTR_TO_QSTR(&fname->cf_name);
-
-		return f2fs_match_ci_name(dir, &cf, de_name, de_name_len);
-	}
+	if (fname->cf_name.name)
+		return f2fs_match_ci_name(dir, &fname->cf_name,
+					  de_name, de_name_len);
 #endif
 	f.usr_fname = fname->usr_fname;
 	f.disk_name = fname->disk_name;
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 3c7cdb70fe2e..2a0cc75665d6 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -515,7 +515,7 @@ struct f2fs_filename {
 	 * internal operation where usr_fname is also NULL.  In all these cases
 	 * we fall back to treating the name as an opaque byte sequence.
 	 */
-	struct fscrypt_str cf_name;
+	struct qstr cf_name;
 #endif
 };
 
@@ -3484,8 +3484,21 @@ int f2fs_get_tmpfile(struct user_namespace *mnt_userns, struct inode *dir,
  * dir.c
  */
 unsigned char f2fs_get_de_type(struct f2fs_dir_entry *de);
+#if IS_ENABLED(CONFIG_UNICODE)
 int f2fs_init_casefolded_name(const struct inode *dir,
 			      struct f2fs_filename *fname);
+void f2fs_free_casefolded_name(struct f2fs_filename *fname);
+#else
+static inline int f2fs_init_casefolded_name(const struct inode *dir,
+					    struct f2fs_filename *fname)
+{
+	return 0;
+}
+static inline void f2fs_free_casefolded_name(struct f2fs_filename *fname)
+{
+}
+#endif /* CONFIG_UNICODE */
+
 int f2fs_setup_filename(struct inode *dir, const struct qstr *iname,
 			int lookup, struct f2fs_filename *fname);
 int f2fs_prepare_lookup(struct inode *dir, struct dentry *dentry,
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index dcd0a1e35095..ead49ea25ae8 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -153,11 +153,8 @@ static int init_recovered_filename(const struct inode *dir,
 		if (err)
 			return err;
 		f2fs_hash_filename(dir, fname);
-#if IS_ENABLED(CONFIG_UNICODE)
 		/* Case-sensitive match is fine for recovery */
-		kmem_cache_free(f2fs_cf_name_slab, fname->cf_name.name);
-		fname->cf_name.name = NULL;
-#endif
+		f2fs_free_casefolded_name(fname);
 	} else {
 		f2fs_hash_filename(dir, fname);
 	}
-- 
2.37.3