fs: dcache reduce branches in lookup path

Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 88bfe68..e3b10ca 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -135,9 +135,9 @@
 			      struct inode *newinode)
 {
 	if (tcon->nocase)
-		direntry->d_op = &cifs_ci_dentry_ops;
+		d_set_d_op(direntry, &cifs_ci_dentry_ops);
 	else
-		direntry->d_op = &cifs_dentry_ops;
+		d_set_d_op(direntry, &cifs_dentry_ops);
 	d_instantiate(direntry, newinode);
 }
 
@@ -421,9 +421,9 @@
 		rc = cifs_get_inode_info_unix(&newinode, full_path,
 						inode->i_sb, xid);
 		if (pTcon->nocase)
-			direntry->d_op = &cifs_ci_dentry_ops;
+			d_set_d_op(direntry, &cifs_ci_dentry_ops);
 		else
-			direntry->d_op = &cifs_dentry_ops;
+			d_set_d_op(direntry, &cifs_dentry_ops);
 
 		if (rc == 0)
 			d_instantiate(direntry, newinode);
@@ -604,9 +604,9 @@
 
 	if ((rc == 0) && (newInode != NULL)) {
 		if (pTcon->nocase)
-			direntry->d_op = &cifs_ci_dentry_ops;
+			d_set_d_op(direntry, &cifs_ci_dentry_ops);
 		else
-			direntry->d_op = &cifs_dentry_ops;
+			d_set_d_op(direntry, &cifs_dentry_ops);
 		d_add(direntry, newInode);
 		if (posix_open) {
 			filp = lookup_instantiate_filp(nd, direntry,
@@ -634,9 +634,9 @@
 		rc = 0;
 		direntry->d_time = jiffies;
 		if (pTcon->nocase)
-			direntry->d_op = &cifs_ci_dentry_ops;
+			d_set_d_op(direntry, &cifs_ci_dentry_ops);
 		else
-			direntry->d_op = &cifs_dentry_ops;
+			d_set_d_op(direntry, &cifs_dentry_ops);
 		d_add(direntry, NULL);
 	/*	if it was once a directory (but how can we tell?) we could do
 		shrink_dcache_parent(direntry); */
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 99b9a2c..2a239d8 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1319,9 +1319,9 @@
 	to set uid/gid */
 			inc_nlink(inode);
 			if (pTcon->nocase)
-				direntry->d_op = &cifs_ci_dentry_ops;
+				d_set_d_op(direntry, &cifs_ci_dentry_ops);
 			else
-				direntry->d_op = &cifs_dentry_ops;
+				d_set_d_op(direntry, &cifs_dentry_ops);
 
 			cifs_unix_basic_to_fattr(&fattr, pInfo, cifs_sb);
 			cifs_fill_uniqueid(inode->i_sb, &fattr);
@@ -1363,9 +1363,9 @@
 						 inode->i_sb, xid, NULL);
 
 		if (pTcon->nocase)
-			direntry->d_op = &cifs_ci_dentry_ops;
+			d_set_d_op(direntry, &cifs_ci_dentry_ops);
 		else
-			direntry->d_op = &cifs_dentry_ops;
+			d_set_d_op(direntry, &cifs_dentry_ops);
 		d_instantiate(direntry, newinode);
 		 /* setting nlink not necessary except in cases where we
 		  * failed to get it from the server or was set bogus */
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 85cdbf8..fe2f6a9 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -525,9 +525,9 @@
 			      rc);
 		} else {
 			if (pTcon->nocase)
-				direntry->d_op = &cifs_ci_dentry_ops;
+				d_set_d_op(direntry, &cifs_ci_dentry_ops);
 			else
-				direntry->d_op = &cifs_dentry_ops;
+				d_set_d_op(direntry, &cifs_dentry_ops);
 			d_instantiate(direntry, newinode);
 		}
 	}
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index ee463ae..ec5b68e 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -103,9 +103,9 @@
 	}
 
 	if (cifs_sb_master_tcon(CIFS_SB(sb))->nocase)
-		dentry->d_op = &cifs_ci_dentry_ops;
+		d_set_d_op(dentry, &cifs_ci_dentry_ops);
 	else
-		dentry->d_op = &cifs_dentry_ops;
+		d_set_d_op(dentry, &cifs_dentry_ops);
 
 	alias = d_materialise_unique(dentry, inode);
 	if (alias != NULL) {