[PATCH 6.6.y 1/2] ext4: Move CONFIG_UNICODE defguards into the code flow

[Sasha Levin <sashal@kernel.org>]

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

[ Upstream commit d98c822232f8642960a69caedeb7909471127939 ]

Instead of a bunch of ifdefs, make the unicode built checks part of the
code flow where possible, as requested by Torvalds.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
[eugen.hristev@collabora.com: port to 6.10-rc1]
Signed-off-by: Eugen Hristev <eugen.hristev@collabora.com>
Link: https://lore.kernel.org/r/20240606073353.47130-7-eugen.hristev@collabora.com
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Stable-dep-of: 19e16597f9ba ("ext4: fix ABBA deadlock in ext4_rmdir()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/crypto.c | 10 ++--------
 fs/ext4/ext4.h   | 33 +++++++++++++++++++++------------
 fs/ext4/namei.c  | 14 +++++---------
 fs/ext4/super.c  |  4 +---
 4 files changed, 29 insertions(+), 32 deletions(-)

diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index 8497f6125a8eb..c52971f62e525 100644
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -31,11 +31,10 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
 
 	ext4_fname_from_fscrypt_name(fname, &name);
 
-#if IS_ENABLED(CONFIG_UNICODE)
 	err = ext4_fname_setup_ci_filename(dir, iname, fname);
 	if (err)
 		ext4_fname_free_filename(fname);
-#endif
+
 	return err;
 }
 
@@ -51,11 +50,9 @@ int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,
 
 	ext4_fname_from_fscrypt_name(fname, &name);
 
-#if IS_ENABLED(CONFIG_UNICODE)
 	err = ext4_fname_setup_ci_filename(dir, &dentry->d_name, fname);
 	if (err)
 		ext4_fname_free_filename(fname);
-#endif
 	return err;
 }
 
@@ -70,10 +67,7 @@ void ext4_fname_free_filename(struct ext4_filename *fname)
 	fname->usr_fname = NULL;
 	fname->disk_name.name = NULL;
 
-#if IS_ENABLED(CONFIG_UNICODE)
-	kfree(fname->cf_name.name);
-	fname->cf_name.name = NULL;
-#endif
+	ext4_fname_free_ci_filename(fname);
 }
 
 static bool uuid_is_zero(__u8 u[16])
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 5a9a05d62f549..c3200c942d676 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2747,8 +2747,25 @@ ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
 
 #if IS_ENABLED(CONFIG_UNICODE)
 extern int ext4_fname_setup_ci_filename(struct inode *dir,
-					 const struct qstr *iname,
-					 struct ext4_filename *fname);
+					const struct qstr *iname,
+					struct ext4_filename *fname);
+
+static inline void ext4_fname_free_ci_filename(struct ext4_filename *fname)
+{
+	kfree(fname->cf_name.name);
+	fname->cf_name.name = NULL;
+}
+#else
+static inline int ext4_fname_setup_ci_filename(struct inode *dir,
+					       const struct qstr *iname,
+					       struct ext4_filename *fname)
+{
+	return 0;
+}
+
+static inline void ext4_fname_free_ci_filename(struct ext4_filename *fname)
+{
+}
 #endif
 
 /* ext4 encryption related stuff goes here crypto.c */
@@ -2771,16 +2788,11 @@ static inline int ext4_fname_setup_filename(struct inode *dir,
 					    int lookup,
 					    struct ext4_filename *fname)
 {
-	int err = 0;
 	fname->usr_fname = iname;
 	fname->disk_name.name = (unsigned char *) iname->name;
 	fname->disk_name.len = iname->len;
 
-#if IS_ENABLED(CONFIG_UNICODE)
-	err = ext4_fname_setup_ci_filename(dir, iname, fname);
-#endif
-
-	return err;
+	return ext4_fname_setup_ci_filename(dir, iname, fname);
 }
 
 static inline int ext4_fname_prepare_lookup(struct inode *dir,
@@ -2792,10 +2804,7 @@ static inline int ext4_fname_prepare_lookup(struct inode *dir,
 
 static inline void ext4_fname_free_filename(struct ext4_filename *fname)
 {
-#if IS_ENABLED(CONFIG_UNICODE)
-	kfree(fname->cf_name.name);
-	fname->cf_name.name = NULL;
-#endif
+	ext4_fname_free_ci_filename(fname);
 }
 
 static inline int ext4_ioctl_get_encryption_pwsalt(struct file *filp,
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 1e72aa6f207ed..c77a18ce76bc7 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1875,8 +1875,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
 		}
 	}
 
-#if IS_ENABLED(CONFIG_UNICODE)
-	if (!inode && IS_CASEFOLDED(dir)) {
+	if (IS_ENABLED(CONFIG_UNICODE) && !inode && IS_CASEFOLDED(dir)) {
 		/* Eventually we want to call d_add_ci(dentry, NULL)
 		 * for negative dentries in the encoding case as
 		 * well.  For now, prevent the negative dentry
@@ -1884,7 +1883,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
 		 */
 		return NULL;
 	}
-#endif
+
 	return d_splice_alias(inode, dentry);
 }
 
@@ -3260,16 +3259,14 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
 	ext4_fc_track_unlink(handle, dentry);
 	retval = ext4_mark_inode_dirty(handle, dir);
 
-#if IS_ENABLED(CONFIG_UNICODE)
 	/* VFS negative dentries are incompatible with Encoding and
 	 * Case-insensitiveness. Eventually we'll want avoid
 	 * invalidating the dentries here, alongside with returning the
 	 * negative dentries at ext4_lookup(), when it is better
 	 * supported by the VFS for the CI case.
 	 */
-	if (IS_CASEFOLDED(dir))
+	if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
 		d_invalidate(dentry);
-#endif
 
 end_rmdir:
 	brelse(bh);
@@ -3371,16 +3368,15 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
 		goto out_trace;
 
 	retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry);
-#if IS_ENABLED(CONFIG_UNICODE)
+
 	/* VFS negative dentries are incompatible with Encoding and
 	 * Case-insensitiveness. Eventually we'll want avoid
 	 * invalidating the dentries here, alongside with returning the
 	 * negative dentries at ext4_lookup(), when it is  better
 	 * supported by the VFS for the CI case.
 	 */
-	if (IS_CASEFOLDED(dir))
+	if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
 		d_invalidate(dentry);
-#endif
 
 out_trace:
 	trace_ext4_unlink_exit(dentry, retval);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9be69402c704e..f91f36c39651c 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3630,14 +3630,12 @@ int ext4_feature_set_ok(struct super_block *sb, int readonly)
 		return 0;
 	}
 
-#if !IS_ENABLED(CONFIG_UNICODE)
-	if (ext4_has_feature_casefold(sb)) {
+	if (!IS_ENABLED(CONFIG_UNICODE) && ext4_has_feature_casefold(sb)) {
 		ext4_msg(sb, KERN_ERR,
 			 "Filesystem with casefold feature cannot be "
 			 "mounted without CONFIG_UNICODE");
 		return 0;
 	}
-#endif
 
 	if (readonly)
 		return 1;
-- 
2.53.0