Btrfs: early reference counting

Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 3c5f4c2dd525d36667d9360b96bffce6004b6d8f..1118986d7569f07720d71b456a6a410c1e4b693d 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -34,6 +34,37 @@ void release_path(struct ctree_root *root, struct ctree_path *p)
        memset(p, 0, sizeof(*p));
 }
 
+int btrfs_cow_block(struct ctree_root *root,
+                   struct tree_buffer *buf,
+                   struct tree_buffer *parent,
+                   int parent_slot,
+                   struct tree_buffer **cow_ret)
+{
+       struct tree_buffer *cow;
+
+       if (!list_empty(&buf->dirty)) {
+               *cow_ret = buf;
+               return 0;
+       }
+       cow = alloc_free_block(root);
+       memcpy(&cow->node, &buf->node, sizeof(buf->node));
+       cow->node.header.blocknr = cow->blocknr;
+       *cow_ret = cow;
+       if (buf == root->node) {
+               root->node = cow;
+               cow->count++;
+               tree_block_release(root, buf);
+       } else {
+               parent->node.blockptrs[parent_slot] = cow->blocknr;
+               BUG_ON(list_empty(&parent->dirty));
+       }
+       if (0 && root != root->extent_root && !is_leaf(cow->node.header.flags)) {
+               btrfs_inc_ref(root, cow);
+       }
+       tree_block_release(root, buf);
+       return 0;
+}
+
 /*
  * The leaf data grows from end-to-front in the node.
  * this returns the address of the start of the last item,
@@ -263,6 +294,8 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
 
        /* first, try to make some room in the middle buffer */
        if (left_buf) {
+               btrfs_cow_block(root, left_buf, parent_buf,
+                               pslot - 1, &left_buf);
                left = &left_buf->node;
                orig_slot += left->header.nritems;
                wret = push_node_left(root, left_buf, mid_buf);
@@ -274,6 +307,8 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
         * then try to empty the right most buffer into the middle
         */
        if (right_buf) {
+               btrfs_cow_block(root, right_buf, parent_buf,
+                               pslot + 1, &right_buf);
                right = &right_buf->node;
                wret = push_node_left(root, mid_buf, right_buf);
                if (wret < 0)
@@ -293,9 +328,7 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
                } else {
                        memcpy(parent->keys + pslot + 1, right->keys,
                                sizeof(struct key));
-                       wret = dirty_tree_block(root, parent_buf);
-                       if (wret)
-                               ret = wret;
+                       BUG_ON(list_empty(&parent_buf->dirty));
                }
        }
        if (mid->header.nritems == 1) {
@@ -330,9 +363,7 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
        } else {
                /* update the parent key to reflect our changes */
                memcpy(parent->keys + pslot, mid->keys, sizeof(struct key));
-               wret = dirty_tree_block(root, parent_buf);
-               if (wret)
-                       ret = wret;
+               BUG_ON(list_empty(&parent_buf->dirty));
        }
 
        /* update the path */
@@ -375,9 +406,10 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
  * possible)
  */
 int search_slot(struct ctree_root *root, struct key *key,
-               struct ctree_path *p, int ins_len)
+               struct ctree_path *p, int ins_len, int cow)
 {
        struct tree_buffer *b;
+       struct tree_buffer *cow_buf;
        struct node *c;
        int slot;
        int ret;
@@ -387,8 +419,15 @@ again:
        b = root->node;
        b->count++;
        while (b) {
+               level = node_level(b->node.header.flags);
+               if (cow) {
+                       int wret;
+                       wret = btrfs_cow_block(root, b, p->nodes[level + 1],
+                                              p->slots[level + 1], &cow_buf);
+                       b = cow_buf;
+               }
+               BUG_ON(!cow && ins_len);
                c = &b->node;
-               level = node_level(c->header.flags);
                p->nodes[level] = b;
                ret = check_block(p, level);
                if (ret)
@@ -453,7 +492,6 @@ static int fixup_low_keys(struct ctree_root *root,
 {
        int i;
        int ret = 0;
-       int wret;
        for (i = level; i < MAX_LEVEL; i++) {
                struct node *t;
                int tslot = path->slots[i];
@@ -461,9 +499,7 @@ static int fixup_low_keys(struct ctree_root *root,
                        break;
                t = &path->nodes[i]->node;
                memcpy(t->keys + tslot, key, sizeof(*key));
-               wret = dirty_tree_block(root, path->nodes[i]);
-               if (wret)
-                       ret = wret;
+               BUG_ON(list_empty(&path->nodes[i]->dirty));
                if (tslot != 0)
                        break;
        }
@@ -486,7 +522,6 @@ static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf,
        int src_nritems;
        int dst_nritems;
        int ret = 0;
-       int wret;
 
        src_nritems = src->header.nritems;
        dst_nritems = dst->header.nritems;
@@ -511,13 +546,8 @@ static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf,
        src->header.nritems -= push_items;
        dst->header.nritems += push_items;
 
-       wret = dirty_tree_block(root, src_buf);
-       if (wret < 0)
-               ret = wret;
-
-       wret = dirty_tree_block(root, dst_buf);
-       if (wret < 0)
-               ret = wret;
+       BUG_ON(list_empty(&src_buf->dirty));
+       BUG_ON(list_empty(&dst_buf->dirty));
        return ret;
 }
 
@@ -541,7 +571,6 @@ static int balance_node_right(struct ctree_root *root,
        int src_nritems;
        int dst_nritems;
        int ret = 0;
-       int wret;
 
        src_nritems = src->header.nritems;
        dst_nritems = dst->header.nritems;
@@ -569,13 +598,8 @@ static int balance_node_right(struct ctree_root *root,
        src->header.nritems -= push_items;
        dst->header.nritems += push_items;
 
-       wret = dirty_tree_block(root, src_buf);
-       if (wret < 0)
-               ret = wret;
-
-       wret = dirty_tree_block(root, dst_buf);
-       if (wret < 0)
-               ret = wret;
+       BUG_ON(list_empty(&src_buf->dirty));
+       BUG_ON(list_empty(&dst_buf->dirty));
        return ret;
 }
 
@@ -615,7 +639,6 @@ static int insert_new_root(struct ctree_root *root,
        tree_block_release(root, root->node);
        root->node = t;
        t->count++;
-       dirty_tree_block(root, t);
        path->nodes[level] = t;
        path->slots[level] = 0;
        return 0;
@@ -655,7 +678,7 @@ static int insert_ptr(struct ctree_root *root,
        lower->header.nritems++;
        if (lower->keys[1].objectid == 0)
                        BUG();
-       dirty_tree_block(root, path->nodes[level]);
+       BUG_ON(list_empty(&path->nodes[level]->dirty));
        return 0;
 }
 
@@ -701,12 +724,7 @@ static int split_node(struct ctree_root *root, struct ctree_path *path,
        c->header.nritems = mid;
        ret = 0;
 
-       wret = dirty_tree_block(root, t);
-       if (wret)
-               ret = wret;
-       wret = dirty_tree_block(root, split_buffer);
-       if (wret)
-               ret = wret;
+       BUG_ON(list_empty(&t->dirty));
        wret = insert_ptr(root, path, split->keys, split_buffer->blocknr,
                          path->slots[level + 1] + 1, level + 1);
        if (wret)
@@ -778,6 +796,15 @@ static int push_leaf_right(struct ctree_root *root, struct ctree_path *path,
                tree_block_release(root, right_buf);
                return 1;
        }
+       /* cow and double check */
+       btrfs_cow_block(root, right_buf, upper, slot + 1, &right_buf);
+       right = &right_buf->leaf;
+       free_space = leaf_free_space(right);
+       if (free_space < data_size + sizeof(struct item)) {
+               tree_block_release(root, right_buf);
+               return 1;
+       }
+
        for (i = left->header.nritems - 1; i >= 0; i--) {
                item = left->items + i;
                if (path->slots[0] == i)
@@ -818,11 +845,12 @@ static int push_leaf_right(struct ctree_root *root, struct ctree_path *path,
        }
        left->header.nritems -= push_items;
 
-       dirty_tree_block(root, left_buf);
-       dirty_tree_block(root, right_buf);
+       BUG_ON(list_empty(&left_buf->dirty));
+       BUG_ON(list_empty(&right_buf->dirty));
        memcpy(upper->node.keys + slot + 1,
                &right->items[0].key, sizeof(struct key));
-       dirty_tree_block(root, upper);
+       BUG_ON(list_empty(&upper->dirty));
+
        /* then fixup the leaf pointer in the path */
        if (path->slots[0] >= left->header.nritems) {
                path->slots[0] -= left->header.nritems;
@@ -869,6 +897,16 @@ static int push_leaf_left(struct ctree_root *root, struct ctree_path *path,
                tree_block_release(root, t);
                return 1;
        }
+
+       /* cow and double check */
+       btrfs_cow_block(root, t, path->nodes[1], slot - 1, &t);
+       left = &t->leaf;
+       free_space = leaf_free_space(left);
+       if (free_space < data_size + sizeof(struct item)) {
+               tree_block_release(root, t);
+               return 1;
+       }
+
        for (i = 0; i < right->header.nritems; i++) {
                item = right->items + i;
                if (path->slots[0] == i)
@@ -912,12 +950,8 @@ static int push_leaf_left(struct ctree_root *root, struct ctree_path *path,
                push_space = right->items[i].offset;
        }
 
-       wret = dirty_tree_block(root, t);
-       if (wret)
-               ret = wret;
-       wret = dirty_tree_block(root, right_buf);
-       if (wret)
-               ret = wret;
+       BUG_ON(list_empty(&t->dirty));
+       BUG_ON(list_empty(&right_buf->dirty));
 
        wret = fixup_low_keys(root, path, &right->items[0].key, 1);
        if (wret)
@@ -968,6 +1002,7 @@ static int split_leaf(struct ctree_root *root, struct ctree_path *path,
                if (wret < 0)
                        return wret;
        }
+
        l_buf = path->nodes[0];
        l = &l_buf->leaf;
 
@@ -1022,13 +1057,8 @@ static int split_leaf(struct ctree_root *root, struct ctree_path *path,
                          right_buffer->blocknr, path->slots[1] + 1, 1);
        if (wret)
                ret = wret;
-       wret = dirty_tree_block(root, right_buffer);
-       if (wret)
-               ret = wret;
-       wret = dirty_tree_block(root, l_buf);
-       if (wret)
-               ret = wret;
-
+       BUG_ON(list_empty(&right_buffer->dirty));
+       BUG_ON(list_empty(&l_buf->dirty));
        BUG_ON(path->slots[0] != slot);
        if (mid <= slot) {
                tree_block_release(root, path->nodes[0]);
@@ -1049,7 +1079,6 @@ int insert_item(struct ctree_root *root, struct key *key,
                          void *data, int data_size)
 {
        int ret = 0;
-       int wret;
        int slot;
        int slot_orig;
        struct leaf *leaf;
@@ -1062,7 +1091,7 @@ int insert_item(struct ctree_root *root, struct key *key,
        if (!root->node)
                BUG();
        init_path(&path);
-       ret = search_slot(root, key, &path, data_size);
+       ret = search_slot(root, key, &path, data_size, 1);
        if (ret == 0) {
                release_path(root, &path);
                return -EEXIST;
@@ -1114,10 +1143,7 @@ int insert_item(struct ctree_root *root, struct key *key,
        if (slot == 0)
                ret = fixup_low_keys(root, &path, key, 1);
 
-       wret = dirty_tree_block(root, leaf_buf);
-       if (wret)
-               ret = wret;
-
+       BUG_ON(list_empty(&leaf_buf->dirty));
        if (leaf_free_space(leaf) < 0)
                BUG();
        check_leaf(&path, 0);
@@ -1162,9 +1188,7 @@ static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level,
                if (wret)
                        ret = wret;
        }
-       wret = dirty_tree_block(root, parent);
-       if (wret)
-               ret = wret;
+       BUG_ON(list_empty(&parent->dirty));
        return ret;
 }
 
@@ -1205,7 +1229,7 @@ int del_item(struct ctree_root *root, struct ctree_path *path)
        if (leaf->header.nritems == 0) {
                if (leaf_buf == root->node) {
                        leaf->header.flags = node_level(0);
-                       dirty_tree_block(root, leaf_buf);
+                       BUG_ON(list_empty(&leaf_buf->dirty));
                } else {
                        clean_tree_block(root, leaf_buf);
                        wret = del_ptr(root, path, 1, path->slots[1]);
@@ -1223,9 +1247,7 @@ int del_item(struct ctree_root *root, struct ctree_path *path)
                        if (wret)
                                ret = wret;
                }
-               wret = dirty_tree_block(root, leaf_buf);
-               if (wret)
-                       ret = wret;
+               BUG_ON(list_empty(&leaf_buf->dirty));
 
                /* delete the leaf if it is mostly empty */
                if (used < LEAF_DATA_SIZE / 3) {
@@ -1304,3 +1326,4 @@ int next_leaf(struct ctree_root *root, struct ctree_path *path)
        return 0;
 }
 
+

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 6b4dabd47698c0bc6842a098d79fb085d7751292..9fe8ba6e25c135758f69160764ef4e31e9fac7e3 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -142,8 +142,9 @@ struct ctree_path {
 };
 
 struct tree_buffer *alloc_free_block(struct ctree_root *root);
+int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf);
 int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks);
-int search_slot(struct ctree_root *root, struct key *key, struct ctree_path *p, int ins_len);
+int search_slot(struct ctree_root *root, struct key *key, struct ctree_path *p, int ins_len, int cow);
 void release_path(struct ctree_root *root, struct ctree_path *p);
 void init_path(struct ctree_path *p);
 int del_item(struct ctree_root *root, struct ctree_path *path);

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b1a8149bbc842f744942ab9c1ccb234f04afed6e..0e1c31e682fb444f159b7eabc262365d3a99b1d2 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -260,6 +260,8 @@ void tree_block_release(struct ctree_root *root, struct tree_buffer *buf)
        if (buf->count < 0)
                BUG();
        if (buf->count == 0) {
+               BUG_ON(!list_empty(&buf->cache));
+               BUG_ON(!list_empty(&buf->dirty));
                if (!radix_tree_lookup(&root->cache_radix, buf->blocknr))
                        BUG();
                radix_tree_delete(&root->cache_radix, buf->blocknr);

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fb21444962155ec86467b8556b0df08abd02ae6e..25d9cd169209d362b4d77ed9a07c5a53bc541344 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -15,6 +15,39 @@
  */
 #define CTREE_EXTENT_PENDING 0
 
+static int inc_block_ref(struct ctree_root *root, u64 blocknr)
+{
+       struct ctree_path path;
+       int ret;
+       struct key key;
+       struct leaf *l;
+       struct extent_item *item;
+       init_path(&path);
+       key.objectid = blocknr;
+       key.flags = 0;
+       key.offset = 1;
+       ret = search_slot(root->extent_root, &key, &path, 0, 1);
+       BUG_ON(ret != 0);
+       l = &path.nodes[0]->leaf;
+       item = (struct extent_item *)(l->data +
+                                     l->items[path.slots[0]].offset);
+       item->refs++;
+       BUG_ON(list_empty(&path.nodes[0]->dirty));
+       release_path(root->extent_root, &path);
+       return 0;
+}
+
+int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf)
+{
+       u64 blocknr;
+       int i;
+       for (i = 0; i < buf->node.header.nritems; i++) {
+               blocknr = buf->node.blockptrs[i];
+               inc_block_ref(root, blocknr);
+       }
+       return 0;
+}
+
 /*
  * find all the blocks marked as pending in the radix tree and remove
  * them from the extent map
@@ -39,7 +72,7 @@ static int del_pending_extents(struct ctree_root *extent_root)
                        key.flags = 0;
                        key.offset = 1;
                        init_path(&path);
-                       ret = search_slot(extent_root, &key, &path, -1);
+                       ret = search_slot(extent_root, &key, &path, -1, 1);
                        if (ret) {
                                print_tree(extent_root, extent_root->node);
                                printf("unable to find %Lu\n", key.objectid);
@@ -83,7 +116,7 @@ int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks)
                return 0;
        }
        init_path(&path);
-       ret = search_slot(extent_root, &key, &path, -1);
+       ret = search_slot(extent_root, &key, &path, -1, 1);
        if (ret) {
                print_tree(extent_root, extent_root->node);
                printf("failed to find %Lu\n", key.objectid);
@@ -124,7 +157,7 @@ check_failed:
        ins->offset = 0;
        ins->flags = 0;
        start_found = 0;
-       ret = search_slot(root, ins, &path, 0);
+       ret = search_slot(root, ins, &path, 0, 0);
        if (ret < 0)
                goto error;
 
@@ -221,6 +254,8 @@ static int insert_pending_extents(struct ctree_root *extent_root)
                        ret = insert_item(extent_root, &key, &item,
                                          sizeof(item));
                        if (ret) {
+                               printf("%Lu already in tree\n", key.objectid);
+                               print_tree(extent_root, extent_root->node);
                                BUG();
                                // FIXME undo it and return sane
                                return ret;
@@ -228,6 +263,7 @@ static int insert_pending_extents(struct ctree_root *extent_root)
                        radix_tree_tag_clear(&extent_root->cache_radix,
                                             gang[i]->blocknr,
                                             CTREE_EXTENT_PENDING);
+                       printf("%Lu is not pending\n", gang[i]->blocknr);
                        tree_block_release(extent_root, gang[i]);
                }
        }
@@ -266,15 +302,18 @@ int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start,
                if (pending_ret)
                        return pending_ret;
                *buf = find_tree_block(root, ins->objectid);
+               dirty_tree_block(root, *buf);
                return 0;
        }
        /* we're allocating an extent for the extent tree, don't recurse */
        BUG_ON(ins->offset != 1);
        *buf = find_tree_block(root, ins->objectid);
        BUG_ON(!*buf);
+       printf("%Lu is pending\n", ins->objectid);
        radix_tree_tag_set(&root->cache_radix, ins->objectid,
                           CTREE_EXTENT_PENDING);
        (*buf)->count++;
+       dirty_tree_block(root, *buf);
        return 0;
 
 }

diff --git a/fs/btrfs/quick-test.c b/fs/btrfs/quick-test.c
index dbd00c3b7ab4a5e7a518604278d15a8d66a47174..8255f79ceca59bdd15d4a102a752a2313bf92ad2 100644 (file)
--- a/fs/btrfs/quick-test.c
+++ b/fs/btrfs/quick-test.c
@@ -19,7 +19,7 @@ int main(int ac, char **av) {
        int i;
        int num;
        int ret;
-       int run_size = 100000;
+       int run_size = 1024;
        int max_key =  100000000;
        int tree_size = 0;
        struct ctree_path path;
@@ -57,7 +57,7 @@ int main(int ac, char **av) {
                init_path(&path);
                if (i % 10000 == 0)
                        fprintf(stderr, "search %d:%d\n", num, i);
-               ret = search_slot(root, &ins, &path, 0);
+               ret = search_slot(root, &ins, &path, 0, 0);
                if (ret) {
                        print_tree(root, root->node);
                        printf("unable to find %d\n", num);
@@ -79,7 +79,7 @@ int main(int ac, char **av) {
                num = next_key(i, max_key);
                ins.objectid = num;
                init_path(&path);
-               ret = search_slot(root, &ins, &path, -1);
+               ret = search_slot(root, &ins, &path, -1, 1);
                if (!ret) {
                        if (i % 10000 == 0)
                                fprintf(stderr, "del %d:%d\n", num, i);
@@ -117,7 +117,7 @@ int main(int ac, char **av) {
                init_path(&path);
                if (i % 10000 == 0)
                        fprintf(stderr, "search %d:%d\n", num, i);
-               ret = search_slot(root, &ins, &path, 0);
+               ret = search_slot(root, &ins, &path, 0, 0);
                if (ret) {
                        print_tree(root, root->node);
                        printf("unable to find %d\n", num);
@@ -131,7 +131,7 @@ int main(int ac, char **av) {
                int slot;
                ins.objectid = (u64)-1;
                init_path(&path);
-               ret = search_slot(root, &ins, &path, -1);
+               ret = search_slot(root, &ins, &path, -1, 1);
                if (ret == 0)
                        BUG();
 

diff --git a/fs/btrfs/random-test.c b/fs/btrfs/random-test.c
index 53245c5039dcd93316e0c846469e35ab33b0b47b..dcc852ad67373c36074e79f6e642cb0eebea3d3d 100644 (file)
--- a/fs/btrfs/random-test.c
+++ b/fs/btrfs/random-test.c
@@ -93,7 +93,7 @@ static int del_one(struct ctree_root *root, struct radix_tree_root *radix)
        ret = setup_key(radix, &key, 1);
        if (ret < 0)
                return 0;
-       ret = search_slot(root, &key, &path, -1);
+       ret = search_slot(root, &key, &path, -1, 1);
        if (ret)
                goto error;
        ret = del_item(root, &path);
@@ -118,7 +118,7 @@ static int lookup_item(struct ctree_root *root, struct radix_tree_root *radix)
        ret = setup_key(radix, &key, 1);
        if (ret < 0)
                return 0;
-       ret = search_slot(root, &key, &path, 0);
+       ret = search_slot(root, &key, &path, 0, 1);
        release_path(root, &path);
        if (ret)
                goto error;
@@ -137,7 +137,7 @@ static int lookup_enoent(struct ctree_root *root, struct radix_tree_root *radix)
        ret = setup_key(radix, &key, 0);
        if (ret < 0)
                return ret;
-       ret = search_slot(root, &key, &path, 0);
+       ret = search_slot(root, &key, &path, 0, 0);
        release_path(root, &path);
        if (ret <= 0)
                goto error;
@@ -163,7 +163,7 @@ static int empty_tree(struct ctree_root *root, struct radix_tree_root *radix,
        key.objectid = (unsigned long)-1;
        while(nr-- >= 0) {
                init_path(&path);
-               ret = search_slot(root, &key, &path, -1);
+               ret = search_slot(root, &key, &path, -1, 1);
                if (ret < 0) {
                        release_path(root, &path);
                        return ret;
@@ -216,7 +216,7 @@ static int fill_tree(struct ctree_root *root, struct radix_tree_root *radix,
                                return ret;
                        }
                }
-               if (i % 10000 == 0) {
+               if (i && i % 10000 == 0) {
                        printf("bigfill %d\n", i);
                }
                if (!keep_running)
@@ -263,7 +263,7 @@ static int fill_radix(struct ctree_root *root, struct radix_tree_root *radix)
        key.objectid = (unsigned long)-1;
        while(1) {
                init_path(&path);
-               ret = search_slot(root, &key, &path, 0);
+               ret = search_slot(root, &key, &path, 0, 0);
                if (ret < 0) {
                        release_path(root, &path);
                        return ret;