Btrfs: Block sized tree extents and extent deletion

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

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 1b4e82d..f0abcf1 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -8,9 +8,12 @@
 #define SEARCH_READ 0
 #define SEARCH_WRITE 1
 
-static int refill_alloc_extent(struct ctree_root *root);
+#define CTREE_EXTENT_PENDING 0
+
 int split_node(struct ctree_root *root, struct ctree_path *path, int level);
 int split_leaf(struct ctree_root *root, struct ctree_path *path, int data_size);
+struct tree_buffer *alloc_free_block(struct ctree_root *root);
+int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks);
 
 static inline void init_path(struct ctree_path *p)
 {
@@ -682,8 +685,6 @@ int insert_item(struct ctree_root *root, struct key *key,
        unsigned int data_end;
        struct ctree_path path;
 
-       refill_alloc_extent(root);
-
        /* create a root if there isn't one */
        if (!root->node)
                BUG();
@@ -756,6 +757,7 @@ int del_ptr(struct ctree_root *root, struct ctree_path *path, int level)
        struct tree_buffer *t;
        struct node *node;
        int nritems;
+       u64 blocknr;
 
        while(1) {
                t = path->nodes[level];
@@ -774,6 +776,7 @@ int del_ptr(struct ctree_root *root, struct ctree_path *path, int level)
                }
                node->header.nritems--;
                write_tree_block(root, t);
+               blocknr = t->blocknr;
                if (node->header.nritems != 0) {
                        int tslot;
                        if (slot == 0)
@@ -799,6 +802,7 @@ int del_ptr(struct ctree_root *root, struct ctree_path *path, int level)
                        break;
                }
                level++;
+               free_extent(root, blocknr, 1);
                if (!path->nodes[level])
                        BUG();
        }
@@ -841,8 +845,10 @@ int del_item(struct ctree_root *root, struct ctree_path *path)
                if (leaf_buf == root->node) {
                        leaf->header.flags = node_level(0);
                        write_tree_block(root, leaf_buf);
-               } else
+               } else {
                        del_ptr(root, path, 1);
+                       free_extent(root, leaf_buf->blocknr, 1);
+               }
        } else {
                if (slot == 0)
                        fixup_low_keys(root, path, &leaf->items[0].key, 1);
@@ -867,6 +873,72 @@ int del_item(struct ctree_root *root, struct ctree_path *path)
        return 0;
 }
 
+static int del_pending_extents(struct ctree_root *extent_root)
+{
+       int ret;
+       struct key key;
+       struct tree_buffer *gang[4];
+       int i;
+       struct ctree_path path;
+
+       while(1) {
+               ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix,
+                                                (void **)gang, 0, ARRAY_SIZE(gang),
+                                                CTREE_EXTENT_PENDING);
+               if (!ret)
+                       break;
+               for (i = 0; i < ret; i++) {
+                       key.objectid = gang[i]->blocknr;
+                       key.flags = 0;
+                       key.offset = 1;
+                       init_path(&path);
+                       ret = search_slot(extent_root, &key, &path, 0);
+                       if (ret) {
+                               BUG();
+                               // FIXME undo it and return sane
+                               return ret;
+                       }
+                       ret = del_item(extent_root, &path);
+                       if (ret) {
+                               BUG();
+                               return ret;
+                       }
+                       release_path(extent_root, &path);
+                       radix_tree_tag_clear(&extent_root->cache_radix, gang[i]->blocknr,
+                                               CTREE_EXTENT_PENDING);
+                       tree_block_release(extent_root, gang[i]);
+               }
+       }
+       return 0;
+}
+
+int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks)
+{
+       struct ctree_path path;
+       struct key key;
+       struct ctree_root *extent_root = root->extent_root;
+       struct tree_buffer *t;
+       int pending_ret;
+       int ret;
+
+       key.objectid = blocknr;
+       key.flags = 0;
+       key.offset = num_blocks;
+       if (root == extent_root) {
+               t = read_tree_block(root, key.objectid);
+               radix_tree_tag_set(&root->cache_radix, key.objectid, CTREE_EXTENT_PENDING);
+               return 0;
+       }
+       init_path(&path);
+       ret = search_slot(extent_root, &key, &path, 0);
+       if (ret)
+               BUG();
+       ret = del_item(extent_root, &path);
+       release_path(extent_root, &path);
+       pending_ret = del_pending_extents(root->extent_root);
+       return ret ? ret : pending_ret;
+}
+
 int next_leaf(struct ctree_root *root, struct ctree_path *path)
 {
        int slot;
@@ -904,8 +976,8 @@ int next_leaf(struct ctree_root *root, struct ctree_path *path)
        return 0;
 }
 
-int alloc_extent(struct ctree_root *orig_root, u64 num_blocks, u64 search_start,
-                u64 search_end, u64 owner, struct key *ins)
+int find_free_extent(struct ctree_root *orig_root, u64 num_blocks, u64 search_start,
+                        u64 search_end, struct key *ins)
 {
        struct ctree_path path;
        struct key *key;
@@ -915,15 +987,13 @@ int alloc_extent(struct ctree_root *orig_root, u64 num_blocks, u64 search_start,
        u64 last_block;
        int start_found = 0;
        struct leaf *l;
-       struct extent_item extent_item;
        struct ctree_root * root = orig_root->extent_root;
 
        init_path(&path);
        ins->objectid = search_start;
        ins->offset = 0;
        ins->flags = 0;
-
-       ret = search_slot(root, ins, &path, sizeof(struct extent_item));
+       ret = search_slot(root, ins, &path, 0);
        while (1) {
                l = &path.nodes[0]->leaf;
                slot = path.slots[0];
@@ -938,6 +1008,7 @@ int alloc_extent(struct ctree_root *orig_root, u64 num_blocks, u64 search_start,
                                ins->objectid = search_start;
                                ins->offset = num_blocks;
                                hole_size = search_end - search_start;
+                               start_found = 1;
                                goto insert;
                        }
                        ins->objectid = last_block;
@@ -956,51 +1027,119 @@ int alloc_extent(struct ctree_root *orig_root, u64 num_blocks, u64 search_start,
                } else
                        start_found = 1;
                last_block = key->objectid + key->offset;
+insert_failed:
                path.slots[0]++;
        }
        // FIXME -ENOSPC
 insert:
+       if (orig_root->extent_root == orig_root) {
+               BUG_ON(num_blocks != 1);
+               if ((root->current_insert.objectid <= ins->objectid &&
+                   root->current_insert.objectid + root->current_insert.offset >
+                   ins->objectid) ||
+                  (root->current_insert.objectid > ins->objectid &&
+                   root->current_insert.objectid <= ins->objectid + ins->offset) ||
+                  radix_tree_tag_get(&root->cache_radix, ins->objectid,
+                                     CTREE_EXTENT_PENDING)) {
+                       last_block = ins->objectid + 1;
+                       search_start = last_block;
+                       goto insert_failed;
+               }
+       }
        release_path(root, &path);
+       if (ins->offset != 1)
+               BUG();
+       return 0;
+}
+
+static int insert_pending_extents(struct ctree_root *extent_root)
+{
+       int ret;
+       struct key key;
+       struct extent_item item;
+       struct tree_buffer *gang[4];
+       int i;
+
+       // FIXME -ENOSPC
+       item.refs = 1;
+       item.owner = extent_root->node->node.header.parentid;
+       while(1) {
+               ret = radix_tree_gang_lookup_tag(&extent_root->cache_radix,
+                                                (void **)gang, 0, ARRAY_SIZE(gang),
+                                                CTREE_EXTENT_PENDING);
+               if (!ret)
+                       break;
+               for (i = 0; i < ret; i++) {
+                       key.objectid = gang[i]->blocknr;
+                       key.flags = 0;
+                       key.offset = 1;
+                       ret = insert_item(extent_root, &key, &item, sizeof(item));
+                       if (ret) {
+                               BUG();
+                               // FIXME undo it and return sane
+                               return ret;
+                       }
+                       radix_tree_tag_clear(&extent_root->cache_radix, gang[i]->blocknr,
+                                               CTREE_EXTENT_PENDING);
+                       tree_block_release(extent_root, gang[i]);
+               }
+       }
+       return 0;
+}
+
+int alloc_extent(struct ctree_root *root, u64 num_blocks, u64 search_start,
+                        u64 search_end, u64 owner, struct key *ins, struct tree_buffer **buf)
+{
+       int ret;
+       int pending_ret;
+       struct extent_item extent_item;
+
        extent_item.refs = 1;
        extent_item.owner = owner;
-       if (root == orig_root && root->reserve_extent->num_blocks == 0) {
-               root->reserve_extent->blocknr = ins->objectid;
-               root->reserve_extent->num_blocks = ins->offset;
-               root->reserve_extent->num_used = 0;
+
+       ret = find_free_extent(root, num_blocks, search_start, search_end, ins);
+       if (ret)
+               return ret;
+
+       if (root != root->extent_root) {
+               memcpy(&root->extent_root->current_insert, ins, sizeof(*ins));
+               ret = insert_item(root->extent_root, ins, &extent_item, sizeof(extent_item));
+               memset(&root->extent_root->current_insert, 0, sizeof(struct key));
+               pending_ret = insert_pending_extents(root->extent_root);
+               if (ret)
+                       return ret;
+               if (pending_ret)
+                       return pending_ret;
+               *buf = find_tree_block(root, ins->objectid);
+               return 0;
        }
-       ret = insert_item(root->extent_root, ins, &extent_item, sizeof(extent_item));
-       return ret;
+       /* 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);
+       radix_tree_tag_set(&root->cache_radix, ins->objectid, CTREE_EXTENT_PENDING);
+       (*buf)->count++;
+       return 0;
+
 }
 
-static int refill_alloc_extent(struct ctree_root *root)
+struct tree_buffer *alloc_free_block(struct ctree_root *root)
 {
-       struct alloc_extent *ae = root->alloc_extent;
-       struct key key;
+       struct key ins;
        int ret;
-       int min_blocks = MAX_LEVEL * 2;
+       struct tree_buffer *buf = NULL;
 
-       if (ae->num_blocks > ae->num_used && ae->num_blocks - ae->num_used >
-           min_blocks)
-               return 0;
-       ae = root->reserve_extent;
-       if (ae->num_blocks > ae->num_used) {
-               if (root->alloc_extent->num_blocks == 0) {
-                       /* we should swap reserve/alloc_extent when alloc
-                        * fills up
-                        */
-                       BUG();
-               }
-               if (ae->num_blocks - ae->num_used < min_blocks)
-                       BUG();
-               return 0;
+       ret = alloc_extent(root, 1, 0, (unsigned long)-1, root->node->node.header.parentid,
+                          &ins, &buf);
+
+       if (ret) {
+               BUG();
+               return NULL;
        }
-       ret = alloc_extent(root,
-                          min_blocks * 2, 0, (unsigned long)-1,
-                          root->node->node.header.parentid, &key);
-       ae->blocknr = key.objectid;
-       ae->num_blocks = key.offset;
-       ae->num_used = 0;
-       return ret;
+       if (root != root->extent_root)
+               BUG_ON(radix_tree_tag_get(&root->extent_root->cache_radix, buf->blocknr,
+                                         CTREE_EXTENT_PENDING));
+       return buf;
 }
 
 void print_leaf(struct leaf *l)
@@ -1096,6 +1235,7 @@ int main() {
        print_tree(root, root->node);
        printf("map tree\n");
        print_tree(root->extent_root, root->extent_root->node);
+       fflush(stdout);
 
        srand(55);
        for (i = 0; i < run_size; i++) {
@@ -1111,12 +1251,6 @@ int main() {
                if (!ret)
                        tree_size++;
        }
-       printf("root used: %lu\n", root->alloc_extent->num_used);
-       printf("root tree\n");
-       // print_tree(root, root->node);
-       printf("map tree\n");
-       printf("map used: %lu\n", root->extent_root->alloc_extent->num_used);
-       // print_tree(root->extent_root, root->extent_root->node);
        write_ctree_super(root, &super);
        close_ctree(root);
 
@@ -1167,12 +1301,27 @@ int main() {
                ret = insert_item(root, &ins, buf, strlen(buf));
                if (!ret)
                        tree_size++;
+               if (i >= 5) {
+                       struct key ugh;
+                       ugh.objectid = 5;
+                       ugh.flags = 0;
+                       ugh.offset = 0;
+                       init_path(&path);
+                       ret = search_slot(root, &ugh, &path, 0);
+                       if (ret) {
+                               print_tree(root, root->node);
+                               printf("unable to find 5 %d\n", num);
+                               exit(1);
+                       }
+                       release_path(root, &path);
+
+               }
        }
        write_ctree_super(root, &super);
        close_ctree(root);
        root = open_ctree("dbfile", &super);
-       printf("starting search2\n");
        srand(128);
+       printf("starting search2\n");
        for (i = 0; i < run_size; i++) {
                num = next_key(i, max_key);
                ins.objectid = num;
@@ -1219,5 +1368,7 @@ int main() {
        write_ctree_super(root, &super);
        close_ctree(root);
        printf("tree size is now %d\n", tree_size);
+       printf("map tree\n");
+       print_tree(root->extent_root, root->extent_root->node);
        return 0;
 }

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 78407d3..8c32c0e 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -28,21 +28,12 @@ struct header {
 
 struct tree_buffer;
 
-struct alloc_extent {
-       u64 blocknr;
-       u64 num_blocks;
-       u64 num_used;
-} __attribute__ ((__packed__));
-
 struct ctree_root {
        struct tree_buffer *node;
        struct ctree_root *extent_root;
-       struct alloc_extent *alloc_extent;
-       struct alloc_extent *reserve_extent;
+       struct key current_insert;
        int fp;
        struct radix_tree_root cache_radix;
-       struct alloc_extent ai1;
-       struct alloc_extent ai2;
 };
 
 struct ctree_root_info {
@@ -52,8 +43,6 @@ struct ctree_root_info {
        u64 tree_root; /* the tree root */
        u32 csum;
        u32 ham;
-       struct alloc_extent alloc_extent;
-       struct alloc_extent reserve_extent;
        u64 snapuuid[2]; /* root specific uuid */
 } __attribute__ ((__packed__));
 

diff --cc fs/btrfs/disk-io.c
Simple merge

diff --cc fs/btrfs/disk-io.h
Simple merge

diff --cc fs/btrfs/mkfs.c
Simple merge