ovl: allocate an ovl_inode struct
We need some more space to store overlay inode data in memory,
so allocate overlay inodes from a slab of struct ovl_inode.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 34bc4a9..553727d 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -58,3 +58,12 @@
{
return lockless_dereference(oe->__upperdentry);
}
+
+struct ovl_inode {
+ struct inode vfs_inode;
+};
+
+static inline struct ovl_inode *OVL_I(struct inode *inode)
+{
+ return container_of(inode, struct ovl_inode, vfs_inode);
+}
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 4882ffb..ed91601 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -165,6 +165,27 @@
.d_weak_revalidate = ovl_dentry_weak_revalidate,
};
+static struct kmem_cache *ovl_inode_cachep;
+
+static struct inode *ovl_alloc_inode(struct super_block *sb)
+{
+ struct ovl_inode *oi = kmem_cache_alloc(ovl_inode_cachep, GFP_KERNEL);
+
+ return &oi->vfs_inode;
+}
+
+static void ovl_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+
+ kmem_cache_free(ovl_inode_cachep, OVL_I(inode));
+}
+
+static void ovl_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, ovl_i_callback);
+}
+
static void ovl_put_super(struct super_block *sb)
{
struct ovl_fs *ufs = sb->s_fs_info;
@@ -263,12 +284,14 @@
}
static const struct super_operations ovl_super_operations = {
+ .alloc_inode = ovl_alloc_inode,
+ .destroy_inode = ovl_destroy_inode,
+ .drop_inode = generic_delete_inode,
.put_super = ovl_put_super,
.sync_fs = ovl_sync_fs,
.statfs = ovl_statfs,
.show_options = ovl_show_options,
.remount_fs = ovl_remount,
- .drop_inode = generic_delete_inode,
};
enum {
@@ -1038,14 +1061,43 @@
};
MODULE_ALIAS_FS("overlay");
+static void ovl_inode_init_once(void *foo)
+{
+ struct ovl_inode *oi = foo;
+
+ inode_init_once(&oi->vfs_inode);
+}
+
static int __init ovl_init(void)
{
- return register_filesystem(&ovl_fs_type);
+ int err;
+
+ ovl_inode_cachep = kmem_cache_create("ovl_inode",
+ sizeof(struct ovl_inode), 0,
+ (SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD|SLAB_ACCOUNT),
+ ovl_inode_init_once);
+ if (ovl_inode_cachep == NULL)
+ return -ENOMEM;
+
+ err = register_filesystem(&ovl_fs_type);
+ if (err)
+ kmem_cache_destroy(ovl_inode_cachep);
+
+ return err;
}
static void __exit ovl_exit(void)
{
unregister_filesystem(&ovl_fs_type);
+
+ /*
+ * Make sure all delayed rcu free inodes are flushed before we
+ * destroy cache.
+ */
+ rcu_barrier();
+ kmem_cache_destroy(ovl_inode_cachep);
+
}
module_init(ovl_init);