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>

3 files changed, 9 insertions, 9 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index d932fdb6a245..85f0a80912aa 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1969,7 +1969,7 @@ static struct dentry *proc_fd_instantiate(struct inode *dir,
         inode->i_op = &proc_pid_link_inode_operations;
         inode->i_size = 64;
         ei->op.proc_get_link = proc_fd_link;
-        dentry->d_op = &tid_fd_dentry_operations;
+        d_set_d_op(dentry, &tid_fd_dentry_operations);
         d_add(dentry, inode);
         /* Close the race of the process dying before we return the dentry */
         if (tid_fd_revalidate(dentry, NULL))
@@ -2137,7 +2137,7 @@ static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
         ei->fd = fd;
         inode->i_mode = S_IFREG | S_IRUSR;
         inode->i_fop = &proc_fdinfo_file_operations;
-        dentry->d_op = &tid_fd_dentry_operations;
+        d_set_d_op(dentry, &tid_fd_dentry_operations);
         d_add(dentry, inode);
         /* Close the race of the process dying before we return the dentry */
         if (tid_fd_revalidate(dentry, NULL))
@@ -2196,7 +2196,7 @@ static struct dentry *proc_pident_instantiate(struct inode *dir,
         if (p->fop)
                 inode->i_fop = p->fop;
         ei->op = p->op;
-        dentry->d_op = &pid_dentry_operations;
+        d_set_d_op(dentry, &pid_dentry_operations);
         d_add(dentry, inode);
         /* Close the race of the process dying before we return the dentry */
         if (pid_revalidate(dentry, NULL))
@@ -2615,7 +2615,7 @@ static struct dentry *proc_base_instantiate(struct inode *dir,
         if (p->fop)
                 inode->i_fop = p->fop;
         ei->op = p->op;
-        dentry->d_op = &proc_base_dentry_operations;
+        d_set_d_op(dentry, &proc_base_dentry_operations);
         d_add(dentry, inode);
         error = NULL;
 out:
@@ -2926,7 +2926,7 @@ static struct dentry *proc_pid_instantiate(struct inode *dir,
         inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
                 ARRAY_SIZE(tgid_base_stuff));
 
-        dentry->d_op = &pid_dentry_operations;
+        d_set_d_op(dentry, &pid_dentry_operations);
 
         d_add(dentry, inode);
         /* Close the race of the process dying before we return the dentry */
@@ -3169,7 +3169,7 @@ static struct dentry *proc_task_instantiate(struct inode *dir,
         inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
                 ARRAY_SIZE(tid_base_stuff));
 
-        dentry->d_op = &pid_dentry_operations;
+        d_set_d_op(dentry, &pid_dentry_operations);
 
         d_add(dentry, inode);
         /* Close the race of the process dying before we return the dentry */
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 1d607be36d95..f766be29d2c7 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -439,7 +439,7 @@ struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
 out_unlock:
 
         if (inode) {
-                dentry->d_op = &proc_dentry_operations;
+                d_set_d_op(dentry, &proc_dentry_operations);
                 d_add(dentry, inode);
                 return NULL;
         }
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 998e3a715bcc..35efd85a4d32 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -120,7 +120,7 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
                 goto out;
 
         err = NULL;
-        dentry->d_op = &proc_sys_dentry_operations;
+        d_set_d_op(dentry, &proc_sys_dentry_operations);
         d_add(dentry, inode);
 
 out:
@@ -201,7 +201,7 @@ static int proc_sys_fill_cache(struct file *filp, void *dirent,
                                 dput(child);
                                 return -ENOMEM;
                         } else {
-                                child->d_op = &proc_sys_dentry_operations;
+                                d_set_d_op(child, &proc_sys_dentry_operations);
                                 d_add(child, inode);
                         }
                 } else {