ext4 crypto: simplify interfaces to directory entry insert functions

A number of functions include ext4_add_dx_entry, make_indexed_dir,
etc. are being passed a dentry even though the only thing they use is
the containing parent.  We can shrink the code size slightly by making
this replacement.  This will also be useful in cases where we don't
have a dentry as the argument to the directory entry insert functions.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a969ab3..06c3afc 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -273,7 +273,7 @@
 		struct ext4_filename *fname,
 		struct ext4_dir_entry_2 **res_dir);
 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
-			     struct dentry *dentry, struct inode *inode);
+			     struct inode *dir, struct inode *inode);
 
 /* checksumming functions */
 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
@@ -1928,10 +1928,9 @@
  * directory, and adds the dentry to the indexed directory.
  */
 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
-			    struct dentry *dentry,
+			    struct inode *dir,
 			    struct inode *inode, struct buffer_head *bh)
 {
-	struct inode	*dir = d_inode(dentry->d_parent);
 	struct buffer_head *bh2;
 	struct dx_root	*root;
 	struct dx_frame	frames[2], *frame;
@@ -2086,8 +2085,7 @@
 		return retval;
 
 	if (ext4_has_inline_data(dir)) {
-		retval = ext4_try_add_inline_entry(handle, &fname,
-						   dentry, inode);
+		retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
 		if (retval < 0)
 			goto out;
 		if (retval == 1) {
@@ -2097,7 +2095,7 @@
 	}
 
 	if (is_dx(dir)) {
-		retval = ext4_dx_add_entry(handle, &fname, dentry, inode);
+		retval = ext4_dx_add_entry(handle, &fname, dir, inode);
 		if (!retval || (retval != ERR_BAD_DX_DIR))
 			goto out;
 		ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
@@ -2119,7 +2117,7 @@
 
 		if (blocks == 1 && !dx_fallback &&
 		    ext4_has_feature_dir_index(sb)) {
-			retval = make_indexed_dir(handle, &fname, dentry,
+			retval = make_indexed_dir(handle, &fname, dir,
 						  inode, bh);
 			bh = NULL; /* make_indexed_dir releases bh */
 			goto out;
@@ -2154,12 +2152,11 @@
  * Returns 0 for success, or a negative error value
  */
 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
-			     struct dentry *dentry, struct inode *inode)
+			     struct inode *dir, struct inode *inode)
 {
 	struct dx_frame frames[2], *frame;
 	struct dx_entry *entries, *at;
 	struct buffer_head *bh;
-	struct inode *dir = d_inode(dentry->d_parent);
 	struct super_block *sb = dir->i_sb;
 	struct ext4_dir_entry_2 *de;
 	int err;