[RFC v2 14/83] Add range node kmem cache.

Andiry Xu
2018-03-10T18:42:31Z

Range node specifies a range of [start, end]. and is managed by a red-black tree.
NOVA uses range node to manage NVM allocator and inodes being used.

Signed-off-by: Andiry Xu <jix024@cs.ucsd.edu>
---
fs/nova/nova.h | 8 ++++++++
fs/nova/super.c | 45 ++++++++++++++++++++++++++++++++++++++++++---
fs/nova/super.h | 2 ++
3 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/fs/nova/nova.h b/fs/nova/nova.h
index ba7ffca..e0e85fb 100644
--- a/fs/nova/nova.h
+++ b/fs/nova/nova.h
@@ -301,6 +301,14 @@ static inline u64 nova_get_epoch_id(struct super_block *sb)
}

#include "inode.h"
+
+/* A node in the RB tree representing a range of pages */
+struct nova_range_node {
+ struct rb_node node;
+ unsigned long range_low;
+ unsigned long range_high;
+};
+
#include "bbuild.h"

/* ====================================================== */
diff --git a/fs/nova/super.c b/fs/nova/super.c
index f41cc04..aec1cd3 100644
--- a/fs/nova/super.c
+++ b/fs/nova/super.c
@@ -52,6 +52,7 @@ MODULE_PARM_DESC(nova_dbgmask, "Control debugging output");
static struct super_operations nova_sops;

static struct kmem_cache *nova_inode_cachep;
+static struct kmem_cache *nova_range_node_cachep;

/* FIXME: should the following variable be one per NOVA instance? */
@@ -686,6 +687,20 @@ static void nova_put_super(struct super_block *sb)
sb->s_fs_info = NULL;
}

+inline void nova_free_range_node(struct nova_range_node *node)
+{
+ kmem_cache_free(nova_range_node_cachep, node);
+}
+
+inline struct nova_range_node *nova_alloc_range_node(struct super_block *sb)
+{
+ struct nova_range_node *p;
+
+ p = (struct nova_range_node *)
+ kmem_cache_zalloc(nova_range_node_cachep, GFP_NOFS);
+ return p;
+}
+
static struct inode *nova_alloc_inode(struct super_block *sb)
{
struct nova_inode_info *vi;
@@ -719,6 +734,17 @@ static void init_once(void *foo)
inode_init_once(&vi->vfs_inode);
}

+static int __init init_rangenode_cache(void)
+{
+ nova_range_node_cachep = kmem_cache_create("nova_range_node_cache",
+ sizeof(struct nova_range_node),
+ 0, (SLAB_RECLAIM_ACCOUNT |
+ SLAB_MEM_SPREAD), NULL);
+ if (nova_range_node_cachep == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
static int __init init_inodecache(void)
{
nova_inode_cachep = kmem_cache_create("nova_inode_cache",
@@ -740,6 +766,11 @@ static void destroy_inodecache(void)
kmem_cache_destroy(nova_inode_cachep);
}

+static void destroy_rangenode_cache(void)
+{
+ kmem_cache_destroy(nova_range_node_cachep);
+}
+

/*
* the super block writes are all done "on the fly", so the
@@ -781,20 +812,27 @@ static int __init init_nova_fs(void)
nova_info("Arch new instructions support: CLWB %s\n",
support_clwb ? "YES" : "NO");

- rc = init_inodecache();
+ rc = init_rangenode_cache();
if (rc)
goto out;

- rc = register_filesystem(&nova_fs_type);
+ rc = init_inodecache();
if (rc)
goto out1;

+ rc = register_filesystem(&nova_fs_type);
+ if (rc)
+ goto out2;
+
out:
NOVA_END_TIMING(init_t, init_time);
return rc;

-out1:
+out2:
destroy_inodecache();
+
+out1:
+ destroy_rangenode_cache();
goto out;
}

@@ -802,6 +840,7 @@ static void __exit exit_nova_fs(void)
{
unregister_filesystem(&nova_fs_type);
destroy_inodecache();
+ destroy_rangenode_cache();
}

MODULE_AUTHOR("Andiry Xu <jix024@cs.ucsd.edu>");
diff --git a/fs/nova/super.h b/fs/nova/super.h
index cb53908..b478080 100644
--- a/fs/nova/super.h
+++ b/fs/nova/super.h
@@ -145,5 +145,7 @@ static inline struct nova_super_block *nova_get_super(struct super_block *sb)
}

extern void nova_error_mng(struct super_block *sb, const char *fmt, ...);
+extern struct nova_range_node *nova_alloc_range_node(struct super_block *sb);
+extern void nova_free_range_node(struct nova_range_node *node);

#endif
--
2.7.4