Btrfs: Fix extent code to use merge during delete

[deliverable/linux.git] / fs / btrfs / disk-io.c

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f4c6ff202ba913a28c20f8d76a7a90b89259b75c..f7ca5362291ee4c50319f24bcfccd6dc4c3d8cc5 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -11,6 +11,8 @@
 #include "disk-io.h"
 
 static int allocated_blocks = 0;
+int cache_size = 0;
+int cache_max = 10000;
 
 static int check_tree_block(struct ctree_root *root, struct tree_buffer *buf)
 {
@@ -21,6 +23,25 @@ static int check_tree_block(struct ctree_root *root, struct tree_buffer *buf)
        return 0;
 }
 
+static int free_some_buffers(struct ctree_root *root)
+{
+       struct list_head *node, *next;
+       struct tree_buffer *b;
+       if (root->cache_size < cache_max)
+               return 0;
+       list_for_each_safe(node, next, &root->cache) {
+               b = list_entry(node, struct tree_buffer, cache);
+               if (b->count == 1) {
+                       BUG_ON(!list_empty(&b->dirty));
+                       list_del_init(&b->cache);
+                       tree_block_release(root, b);
+                       if (root->cache_size < cache_max)
+                               return 0;
+               }
+       }
+       return 0;
+}
+
 struct tree_buffer *alloc_tree_block(struct ctree_root *root, u64 blocknr)
 {
        struct tree_buffer *buf;
@@ -30,10 +51,14 @@ struct tree_buffer *alloc_tree_block(struct ctree_root *root, u64 blocknr)
                return buf;
        allocated_blocks++;
        buf->blocknr = blocknr;
-       buf->count = 1;
+       buf->count = 2;
+       INIT_LIST_HEAD(&buf->dirty);
+       free_some_buffers(root);
        radix_tree_preload(GFP_KERNEL);
        ret = radix_tree_insert(&root->cache_radix, blocknr, buf);
        radix_tree_preload_end();
+       list_add_tail(&buf->cache, &root->cache);
+       root->cache_size++;
        if (ret) {
                free(buf);
                return NULL;
@@ -57,7 +82,6 @@ struct tree_buffer *find_tree_block(struct ctree_root *root, u64 blocknr)
        return buf;
 }
 
-
 struct tree_buffer *read_tree_block(struct ctree_root *root, u64 blocknr)
 {
        loff_t offset = blocknr * CTREE_BLOCKSIZE;
@@ -82,6 +106,24 @@ struct tree_buffer *read_tree_block(struct ctree_root *root, u64 blocknr)
        return buf;
 }
 
+int dirty_tree_block(struct ctree_root *root, struct tree_buffer *buf)
+{
+       if (!list_empty(&buf->dirty))
+               return 0;
+       list_add_tail(&buf->dirty, &root->trans);
+       buf->count++;
+       return 0;
+}
+
+int clean_tree_block(struct ctree_root *root, struct tree_buffer *buf)
+{
+       if (!list_empty(&buf->dirty)) {
+               list_del_init(&buf->dirty);
+               tree_block_release(root, buf);
+       }
+       return 0;
+}
+
 int write_tree_block(struct ctree_root *root, struct tree_buffer *buf)
 {
        u64 blocknr = buf->blocknr;
@@ -96,9 +138,37 @@ int write_tree_block(struct ctree_root *root, struct tree_buffer *buf)
        return 0;
 }
 
+static int __commit_transaction(struct ctree_root *root)
+{
+       struct tree_buffer *b;
+       int ret = 0;
+       int wret;
+       while(!list_empty(&root->trans)) {
+               b = list_entry(root->trans.next, struct tree_buffer, dirty);
+               list_del_init(&b->dirty);
+               wret = write_tree_block(root, b);
+               if (wret)
+                       ret = wret;
+               tree_block_release(root, b);
+       }
+       return ret;
+}
+
+int commit_transaction(struct ctree_root *root)
+{
+       int ret;
+       ret = __commit_transaction(root);
+       if (!ret && root != root->extent_root)
+               ret = __commit_transaction(root->extent_root);
+       BUG_ON(ret);
+       return ret;
+}
+
 static int __setup_root(struct ctree_root *root, struct ctree_root *extent_root,
                        struct ctree_root_info *info, int fp)
 {
+       INIT_LIST_HEAD(&root->trans);
+       INIT_LIST_HEAD(&root->cache);
        root->fp = fp;
        root->node = NULL;
        root->node = read_tree_block(root, info->tree_root);
@@ -113,7 +183,7 @@ struct ctree_root *open_ctree(char *filename, struct ctree_super_block *super)
        int fp;
        int ret;
 
-       fp = open(filename, O_CREAT | O_RDWR);
+       fp = open(filename, O_CREAT | O_RDWR, 0600);
        if (fp < 0) {
                free(root);
                return NULL;
@@ -157,8 +227,24 @@ int write_ctree_super(struct ctree_root *root, struct ctree_super_block *s)
        return 0;
 }
 
+static int drop_cache(struct ctree_root *root)
+{
+       while(!list_empty(&root->cache)) {
+               struct tree_buffer *b = list_entry(root->cache.next,
+                                                  struct tree_buffer, cache);
+               list_del_init(&b->cache);
+               tree_block_release(root, b);
+       }
+       return 0;
+}
 int close_ctree(struct ctree_root *root)
 {
+       commit_transaction(root);
+       drop_cache(root->extent_root);
+       drop_cache(root);
+       BUG_ON(!list_empty(&root->trans));
+       BUG_ON(!list_empty(&root->extent_root->trans));
+
        close(root->fp);
        if (root->node)
                tree_block_release(root, root->node);
@@ -182,6 +268,8 @@ void tree_block_release(struct ctree_root *root, struct tree_buffer *buf)
                free(buf);
                BUG_ON(allocated_blocks == 0);
                allocated_blocks--;
+               BUG_ON(root->cache_size == 0);
+               root->cache_size--;
        }
 }