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/gfs2/export.c b/fs/gfs2/export.c
index 5ab3839dfcb9..97012ecff560 100644
--- a/fs/gfs2/export.c
+++ b/fs/gfs2/export.c
@@ -130,7 +130,7 @@ static struct dentry *gfs2_get_parent(struct dentry *child)
 
         dentry = d_obtain_alias(gfs2_lookupi(child->d_inode, &gfs2_qdotdot, 1));
         if (!IS_ERR(dentry))
-                dentry->d_op = &gfs2_dops;
+                d_set_d_op(dentry, &gfs2_dops);
         return dentry;
 }
 
@@ -158,7 +158,7 @@ static struct dentry *gfs2_get_dentry(struct super_block *sb,
 out_inode:
         dentry = d_obtain_alias(inode);
         if (!IS_ERR(dentry))
-                dentry->d_op = &gfs2_dops;
+                d_set_d_op(dentry, &gfs2_dops);
         return dentry;
 }