vfs: Merge check_submounts_and_drop and d_invalidate

Now that d_invalidate is the only caller of check_submounts_and_drop,
expand check_submounts_and_drop inline in d_invalidate.

Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 22 insertions, 34 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 484114a4db93..5e02b9eee6b1 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -645,32 +645,6 @@ kill_it:
 }
 EXPORT_SYMBOL(dput);
 
-/**
- * d_invalidate - invalidate a dentry
- * @dentry: dentry to invalidate
- *
- * Try to invalidate the dentry if it turns out to be
- * possible. If there are reasons not to delete it
- * return -EBUSY. On success return 0.
- *
- * no dcache lock.
- */
- 
-int d_invalidate(struct dentry * dentry)
-{
-        /*
-         * If it's already been dropped, return OK.
-         */
-        spin_lock(&dentry->d_lock);
-        if (d_unhashed(dentry)) {
-                spin_unlock(&dentry->d_lock);
-                return 0;
-        }
-        spin_unlock(&dentry->d_lock);
-
-        return check_submounts_and_drop(dentry);
-}
-EXPORT_SYMBOL(d_invalidate);
 
 /* This must be called with d_lock held */
 static inline void __dget_dlock(struct dentry *dentry)
@@ -1190,7 +1164,7 @@ EXPORT_SYMBOL(have_submounts);
  * reachable (e.g. NFS can unhash a directory dentry and then the complete
  * subtree can become unreachable).
  *
- * Only one of check_submounts_and_drop() and d_set_mounted() must succeed.  For
+ * Only one of d_invalidate() and d_set_mounted() must succeed.  For
  * this reason take rename_lock and d_lock on dentry and ancestors.
  */
 int d_set_mounted(struct dentry *dentry)
@@ -1199,7 +1173,7 @@ int d_set_mounted(struct dentry *dentry)
         int ret = -ENOENT;
         write_seqlock(&rename_lock);
         for (p = dentry->d_parent; !IS_ROOT(p); p = p->d_parent) {
-                /* Need exclusion wrt. check_submounts_and_drop() */
+                /* Need exclusion wrt. d_invalidate() */
                 spin_lock(&p->d_lock);
                 if (unlikely(d_unhashed(p))) {
                         spin_unlock(&p->d_lock);
@@ -1369,18 +1343,33 @@ static void check_and_drop(void *_data)
 }
 
 /**
- * check_submounts_and_drop - detach submounts, prune dcache, and drop
+ * d_invalidate - detach submounts, prune dcache, and drop
+ * @dentry: dentry to invalidate (aka detach, prune and drop)
+ *
+ * Try to invalidate the dentry if it turns out to be
+ * possible. If there are reasons not to delete it
+ * return -EBUSY. On success return 0.
+ *
+ * no dcache lock.
  *
  * The final d_drop is done as an atomic operation relative to
  * rename_lock ensuring there are no races with d_set_mounted.  This
  * ensures there are no unhashed dentries on the path to a mountpoint.
- *
- * @dentry: dentry to detach, prune and drop
  */
-int check_submounts_and_drop(struct dentry *dentry)
+int d_invalidate(struct dentry *dentry)
 {
         int ret = 0;
 
+        /*
+         * If it's already been dropped, return OK.
+         */
+        spin_lock(&dentry->d_lock);
+        if (d_unhashed(dentry)) {
+                spin_unlock(&dentry->d_lock);
+                return 0;
+        }
+        spin_unlock(&dentry->d_lock);
+
         /* Negative dentries can be dropped without further checks */
         if (!dentry->d_inode) {
                 d_drop(dentry);
@@ -1414,7 +1403,7 @@ int check_submounts_and_drop(struct dentry *dentry)
 out:
         return ret;
 }
-EXPORT_SYMBOL(check_submounts_and_drop);
+EXPORT_SYMBOL(d_invalidate);
 
 /**
  * __d_alloc    -       allocate a dcache entry
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 75a227cc7ce2..595af29ad145 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -269,7 +269,6 @@ extern void d_prune_aliases(struct inode *);
 
 /* test whether we have any submounts in a subdir tree */
 extern int have_submounts(struct dentry *);
-extern int check_submounts_and_drop(struct dentry *);
 
 /*
  * This adds the entry to the hash queues.