libfs: Drop generic_set_encrypted_ci_d_ops

No filesystems depend on it anymore, and it is generally a bad idea.
Since all dentries should have the same set of dentry operations in
case-insensitive capable filesystems, it should be propagated through
->s_d_op.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240221171412.10710-11-krisman@suse.de
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>

Author: krisman

fs/libfs.c

@@ -1784,40 +1784,6 @@ static const struct dentry_operations generic_encrypted_dentry_ops = {
 };
 #endif
 
-/**
- * generic_set_encrypted_ci_d_ops - helper for setting d_ops for given dentry
- * @dentry:	dentry to set ops on
- *
- * Casefolded directories need d_hash and d_compare set, so that the dentries
- * contained in them are handled case-insensitively.  Note that these operations
- * are needed on the parent directory rather than on the dentries in it, and
- * while the casefolding flag can be toggled on and off on an empty directory,
- * dentry_operations can't be changed later.  As a result, if the filesystem has
- * casefolding support enabled at all, we have to give all dentries the
- * casefolding operations even if their inode doesn't have the casefolding flag
- * currently (and thus the casefolding ops would be no-ops for now).
- *
- * Encryption works differently in that the only dentry operation it needs is
- * d_revalidate, which it only needs on dentries that have the no-key name flag.
- * The no-key flag can't be set "later", so we don't have to worry about that.
- */
-void generic_set_encrypted_ci_d_ops(struct dentry *dentry)
-{
-#if IS_ENABLED(CONFIG_UNICODE)
-	if (dentry->d_sb->s_encoding) {
-		d_set_d_op(dentry, &generic_ci_dentry_ops);
-		return;
-	}
-#endif
-#ifdef CONFIG_FS_ENCRYPTION
-	if (dentry->d_flags & DCACHE_NOKEY_NAME) {
-		d_set_d_op(dentry, &generic_encrypted_dentry_ops);
-		return;
-	}
-#endif
-}
-EXPORT_SYMBOL(generic_set_encrypted_ci_d_ops);
-
 /**
  * generic_set_sb_d_ops - helper for choosing the set of
  * filesystem-wide dentry operations for the enabled features

include/linux/fs.h

@@ -3280,7 +3280,6 @@ extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
 
 extern int generic_check_addressable(unsigned, u64);
 
-extern void generic_set_encrypted_ci_d_ops(struct dentry *dentry);
 extern void generic_set_sb_d_ops(struct super_block *sb);
 
 static inline bool sb_has_encoding(const struct super_block *sb)