fs: avoid inode RCU freeing for pseudo fs
Pseudo filesystems that don't put inode on RCU list or reachable by
rcu-walk dentries do not need to RCU free their inodes.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
diff --git a/fs/inode.c b/fs/inode.c
index 6751dfe..da85e56 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -257,6 +257,12 @@
return inode;
}
+void free_inode_nonrcu(struct inode *inode)
+{
+ kmem_cache_free(inode_cachep, inode);
+}
+EXPORT_SYMBOL(free_inode_nonrcu);
+
void __destroy_inode(struct inode *inode)
{
BUG_ON(inode_has_buffers(inode));
diff --git a/fs/pipe.c b/fs/pipe.c
index 04629f3..ae3592d 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1253,6 +1253,10 @@
return ret;
}
+static const struct super_operations pipefs_ops = {
+ .destroy_inode = free_inode_nonrcu,
+};
+
/*
* pipefs should _never_ be mounted by userland - too much of security hassle,
* no real gain from having the whole whorehouse mounted. So we don't need
@@ -1262,7 +1266,7 @@
static struct dentry *pipefs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
- return mount_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC);
+ return mount_pseudo(fs_type, "pipe:", &pipefs_ops, PIPEFS_MAGIC);
}
static struct file_system_type pipe_fs_type = {