[RFC v1 06/11] vfs: add init and exit support

zwu.kernel
2012-09-17T07:19:35Z

Add initialization function to create some
key data structures when hot tracking is enabled;
Clean up them when hot tracking is disabled.

Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
---
fs/hot_rb.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
fs/hot_rb.h | 1 +
fs/hot_track.c | 15 +++++++++++++++
fs/hot_track.h | 2 ++
fs/namespace.c | 4 ++++
fs/super.c | 6 ++++++
6 files changed, 73 insertions(+), 0 deletions(-)

diff --git a/fs/hot_rb.c b/fs/hot_rb.c
index 6622104..b496053 100644
--- a/fs/hot_rb.c
+++ b/fs/hot_rb.c
@@ -133,6 +133,51 @@ static void hot_rb_free_hot_range_item(struct hot_range_item *hr)
}
}

+static int hot_rb_remove_hot_inode_item(struct hot_inode_tree *tree,
+ struct hot_inode_item *he)
+{
+ int ret = 0;
+ rb_erase(&he->rb_node, &tree->map);
+ he->in_tree = 0;
+ return ret;
+}
+
+static int hot_rb_remove_hot_range_item(struct hot_range_tree *tree,
+ struct hot_range_item *hr)
+{
+ int ret = 0;
+ rb_erase(&hr->rb_node, &tree->map);
+ hr->in_tree = 0;
+ return ret;
+}
+
+/* Frees the entire hot_inode_tree. */
+void hot_rb_inode_tree_free(struct hot_info *root)
+{
+ struct rb_node *node, *node2;
+ struct hot_inode_item *he;
+ struct hot_range_item *hr;
+
+ /* Free hot inode and range trees on fs root */
+ node = rb_first(&root->hot_inode_tree.map);
+
+ while (node) {
+ he = rb_entry(node, struct hot_inode_item, rb_node);
+
+ node2 = rb_first(&he->hot_range_tree.map);
+ while (node2) {
+ hr = rb_entry(node2, struct hot_range_item, rb_node);
+ hot_rb_remove_hot_range_item(&he->hot_range_tree, hr);
+ hot_rb_free_hot_range_item(hr);
+ node2 = rb_first(&he->hot_range_tree.map);
+ }
+
+ hot_rb_remove_hot_inode_item(&root->hot_inode_tree, he);
+ hot_rb_free_hot_inode_item(he);
+ node = rb_first(&root->hot_inode_tree.map);
+ }
+}
+
static struct rb_node *hot_rb_insert_hot_inode_item(struct rb_root *root,
unsigned long inode_num,
struct rb_node *node)
diff --git a/fs/hot_rb.h b/fs/hot_rb.h
index 126160e..e1d74fd 100644
--- a/fs/hot_rb.h
+++ b/fs/hot_rb.h
@@ -42,6 +42,7 @@ struct hot_inode_item
unsigned long inode_num);

void hot_rb_free_hot_inode_item(struct hot_inode_item *he);
+void hot_rb_inode_tree_free(struct hot_info *root);

int __init hot_rb_item_cache_init(void);

diff --git a/fs/hot_track.c b/fs/hot_track.c
index b3f01a1..ea4e436 100644
--- a/fs/hot_track.c
+++ b/fs/hot_track.c
@@ -58,3 +58,18 @@ void __init hot_track_kmem_cache_init(void)
if (hot_rb_item_cache_init())
return;
}
+
+/*
+ * Initialize the data structures for hot data tracking.
+ */
+void hot_track_init(struct super_block *sb, const char *name)
+{
+ sb->s_hotinfo.mount_opt |= HOT_MOUNT_HOT_TRACK;
+ hot_rb_inode_tree_init(&sb->s_hotinfo.hot_inode_tree);
+}
+
+void hot_track_exit(struct super_block *sb)
+{
+ sb->s_hotinfo.mount_opt &= ~HOT_MOUNT_HOT_TRACK;
+ hot_rb_inode_tree_free(&sb->s_hotinfo);
+}
diff --git a/fs/hot_track.h b/fs/hot_track.h
index a099b43..719ed65 100644
--- a/fs/hot_track.h
+++ b/fs/hot_track.h
@@ -17,5 +17,7 @@

bool hot_track_parse_options(char *options);
void __init hot_track_kmem_cache_init(void);
+void hot_track_init(struct super_block *sb, const char *name);
+void hot_track_exit(struct super_block *sb);

#endif /* __HOT_TRACK__ */
diff --git a/fs/namespace.c b/fs/namespace.c
index 4d31f73..90c958a 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -22,6 +22,7 @@
#include <linux/uaccess.h>
#include "pnode.h"
#include "internal.h"
+#include "hot_track.h"

#define HASH_SHIFT ilog2(PAGE_SIZE / sizeof(struct list_head))
#define HASH_SIZE (1UL << HASH_SHIFT)
@@ -1215,6 +1216,9 @@ static int do_umount(struct mount *mnt, int flags)
return retval;
}

+ if (sb->s_hotinfo.mount_opt & HOT_MOUNT_HOT_TRACK)
+ hot_track_exit(sb);
+
down_write(&namespace_sem);
br_write_lock(&vfsmount_lock);
event++;
diff --git a/fs/super.c b/fs/super.c
index d5bc781..eaf95fe 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1153,6 +1153,9 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
WARN_ON(sb->s_bdi == &default_backing_dev_info);
sb->s_flags |= MS_BORN;

+ if (hottrack)
+ hot_track_init(sb, name);
+
error = security_sb_kern_mount(sb, flags, secdata);
if (error)
goto out_sb;
@@ -1170,6 +1173,9 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
free_secdata(secdata);
return root;
out_sb:
+ if (hottrack)
+ hot_track_exit(sb);
+
dput(root);
deactivate_locked_super(sb);
out_free_secdata:
--
1.7.6.5