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>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 57f90dad8919..a151cbdec626 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1466,7 +1466,7 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struc
         jfs_info("jfs_lookup: name = %s", name);
 
         if (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2)
-                dentry->d_op = &jfs_ci_dentry_operations;
+                d_set_d_op(dentry, &jfs_ci_dentry_operations);
 
         if ((name[0] == '.') && (len == 1))
                 inum = dip->i_ino;
@@ -1495,7 +1495,7 @@ static struct dentry *jfs_lookup(struct inode *dip, struct dentry *dentry, struc
         dentry = d_splice_alias(ip, dentry);
 
         if (dentry && (JFS_SBI(dip->i_sb)->mntflag & JFS_OS2))
-                dentry->d_op = &jfs_ci_dentry_operations;
+                d_set_d_op(dentry, &jfs_ci_dentry_operations);
 
         return dentry;
 }