dcache.c: new helper: __d_add()
d_add() with inode->i_lock already held; common to d_add() and
d_splice_alias(). All ->lookup() instances that end up hashing
the dentry they are given will hash it here.
This almost completes the preparations to parallel lookups
proper - the only remaining bit is taking security_d_instantiate()
past d_rehash() and doing rehashing without dropping ->d_lock.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/dcache.c b/fs/dcache.c
index 57da412..32ceae3 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2360,6 +2360,19 @@
}
EXPORT_SYMBOL(d_rehash);
+
+/* inode->i_lock held if inode is non-NULL */
+
+static inline void __d_add(struct dentry *dentry, struct inode *inode)
+{
+ if (inode) {
+ __d_instantiate(dentry, inode);
+ spin_unlock(&inode->i_lock);
+ }
+ security_d_instantiate(dentry, inode);
+ d_rehash(dentry);
+}
+
/**
* d_add - add dentry to hash queues
* @entry: dentry to add
@@ -2371,8 +2384,9 @@
void d_add(struct dentry *entry, struct inode *inode)
{
- d_instantiate(entry, inode);
- d_rehash(entry);
+ if (inode)
+ spin_lock(&inode->i_lock);
+ __d_add(entry, inode);
}
EXPORT_SYMBOL(d_add);
@@ -2798,12 +2812,8 @@
return new;
}
}
- /* already taking inode->i_lock, so d_add() by hand */
- __d_instantiate(dentry, inode);
- spin_unlock(&inode->i_lock);
out:
- security_d_instantiate(dentry, inode);
- d_rehash(dentry);
+ __d_add(dentry, inode);
return NULL;
}
EXPORT_SYMBOL(d_splice_alias);