Btrfs: Fixup last found extent caching

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

4 files changed, 24 insertions, 19 deletions

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index d92d08dde0ff..ae7f4c00c39c 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -1,6 +1,6 @@
 
 CC=gcc
-CFLAGS = -Wall
+CFLAGS = -g -Wall
 headers = radix-tree.h ctree.h disk-io.h kerncompat.h print-tree.h list.h
 objects = ctree.o disk-io.o radix-tree.o mkfs.o extent-tree.o print-tree.o
 
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 4a7bc4e6e747..518326fa3694 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -54,6 +54,7 @@ struct ctree_root {
         struct tree_buffer *commit_root;
         struct ctree_root *extent_root;
         struct key current_insert;
+        struct key last_insert;
         int fp;
         struct radix_tree_root cache_radix;
         struct radix_tree_root pinned_radix;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 2fe31c3508c1..997cc578a185 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -186,6 +186,7 @@ static int __setup_root(struct ctree_root *root, struct ctree_root *extent_root,
         root->commit_root = NULL;
         root->node = read_tree_block(root, info->tree_root);
         memset(&root->current_insert, 0, sizeof(root->current_insert));
+        memset(&root->last_insert, 0, sizeof(root->last_insert));
         return 0;
 }
 
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 8a2b8aaf9b86..dd11532cb2f6 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -102,9 +102,12 @@ int btrfs_finish_extent_commit(struct ctree_root *root)
                                                  ARRAY_SIZE(gang));
                 if (!ret)
                         break;
-                for (i = 0; i < ret; i++)
+                for (i = 0; i < ret; i++) {
                         radix_tree_delete(&extent_root->pinned_radix, gang[i]);
+                }
         }
+        extent_root->last_insert.objectid = 0;
+        extent_root->last_insert.offset = 0;
         return 0;
 }
 
@@ -170,6 +173,9 @@ int __free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks)
                         radix_tree_preload_end();
                 }
                 ret = del_item(extent_root, &path);
+                if (root != extent_root &&
+                    extent_root->last_insert.objectid < blocknr)
+                        extent_root->last_insert.objectid = blocknr;
                 if (ret)
                         BUG();
         }
@@ -261,8 +267,11 @@ static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
         int start_found;
         struct leaf *l;
         struct ctree_root * root = orig_root->extent_root;
-        int total_needed = num_blocks + MAX_LEVEL * 3;
+        int total_needed = num_blocks;
 
+        total_needed += (node_level(root->node->node.header.flags) + 1) * 3;
+        if (root->last_insert.objectid > search_start)
+                search_start = root->last_insert.objectid;
 check_failed:
         init_path(&path);
         ins->objectid = search_start;
@@ -273,6 +282,9 @@ check_failed:
         if (ret < 0)
                 goto error;
 
+        if (path.slots[0] > 0)
+                path.slots[0]--;
+
         while (1) {
                 l = &path.nodes[0]->leaf;
                 slot = path.slots[0];
@@ -293,31 +305,21 @@ check_failed:
                         ins->offset = (u64)-1;
                         goto check_pending;
                 }
-                if (slot == 0) {
-                        int last_slot = l->header.nritems - 1;
-                        u64 span = l->items[last_slot].key.objectid;
-                        span -= l->items[slot].key.objectid;
-                        if (span + total_needed > last_slot - slot) {
-                                path.slots[0] = last_slot + 1;
-                                key = &l->items[last_slot].key;
-                                last_block = key->objectid + key->offset;
-                                start_found = 1;
-                                continue;
-                        }
-                }
                 key = &l->items[slot].key;
                 if (key->objectid >= search_start) {
                         if (start_found) {
+                                if (last_block < search_start)
+                                        last_block = search_start;
                                 hole_size = key->objectid - last_block;
                                 if (hole_size > total_needed) {
                                         ins->objectid = last_block;
                                         ins->offset = hole_size;
                                         goto check_pending;
                                 }
-                        } else
-                                start_found = 1;
-                        last_block = key->objectid + key->offset;
+                        }
                 }
+                start_found = 1;
+                last_block = key->objectid + key->offset;
                 path.slots[0]++;
         }
         // FIXME -ENOSPC
@@ -335,9 +337,10 @@ check_pending:
                 }
         }
         BUG_ON(root->current_insert.offset);
-        root->current_insert.offset = total_needed;
+        root->current_insert.offset = total_needed - num_blocks;
         root->current_insert.objectid = ins->objectid + num_blocks;
         root->current_insert.flags = 0;
+        root->last_insert.objectid = ins->objectid;
         ins->offset = num_blocks;
         return 0;
 error: