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>

2 files changed, 6 insertions, 6 deletions

diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index ac87e49fa706..a7bdb9dcac84 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -309,7 +309,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
                 goto fail_iput;
         pipe = NULL;
 
-        root->d_op = &autofs4_sb_dentry_operations;
+        d_set_d_op(root, &autofs4_sb_dentry_operations);
         root->d_fsdata = ino;
 
         /* Can this call block? */
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 10ca68a96dc7..bfe3f2eb684d 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -571,7 +571,7 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
                  * we check for the hashed dentry and return the newly
                  * hashed dentry.
                  */
-                dentry->d_op = &autofs4_root_dentry_operations;
+                d_set_d_op(dentry, &autofs4_root_dentry_operations);
 
                 /*
                  * And we need to ensure that the same dentry is used for
@@ -710,9 +710,9 @@ static int autofs4_dir_symlink(struct inode *dir,
         d_add(dentry, inode);
 
         if (dir == dir->i_sb->s_root->d_inode)
-                dentry->d_op = &autofs4_root_dentry_operations;
+                d_set_d_op(dentry, &autofs4_root_dentry_operations);
         else
-                dentry->d_op = &autofs4_dentry_operations;
+                d_set_d_op(dentry, &autofs4_dentry_operations);
 
         dentry->d_fsdata = ino;
         ino->dentry = dget(dentry);
@@ -845,9 +845,9 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
         d_add(dentry, inode);
 
         if (dir == dir->i_sb->s_root->d_inode)
-                dentry->d_op = &autofs4_root_dentry_operations;
+                d_set_d_op(dentry, &autofs4_root_dentry_operations);
         else
-                dentry->d_op = &autofs4_dentry_operations;
+                d_set_d_op(dentry, &autofs4_dentry_operations);
 
         dentry->d_fsdata = ino;
         ino->dentry = dget(dentry);