Btrfs: Fix allocation routines to avoid intermixing data and metadata allocations

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

2 files changed, 25 insertions, 19 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0b0c947194ae..72e6b274a450 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -165,7 +165,7 @@ static u64 find_search_start(struct btrfs_root *root,
 {
         int ret;
         struct btrfs_block_group_cache *cache = *cache_ret;
-        u64 last = max(search_start, cache->key.objectid);
+        u64 last;
         u64 start = 0;
         u64 end = 0;
 
@@ -173,11 +173,14 @@ again:
         ret = cache_block_group(root, cache);
         if (ret)
                 goto out;
+        last = max(search_start, cache->key.objectid);
+
         while(1) {
                 ret = find_first_extent_bit(&root->fs_info->free_space_cache,
                                             last, &start, &end, EXTENT_DIRTY);
-                if (ret)
-                        goto out;
+                if (ret) {
+                        goto new_group;
+                }
 
                 start = max(last, start);
                 last = end + 1;
@@ -191,15 +194,13 @@ out:
         return search_start;
 
 new_group:
-        cache = btrfs_lookup_block_group(root->fs_info,
-                                         last + cache->key.offset - 1);
+        last = cache->key.objectid + cache->key.offset;
+        cache = btrfs_lookup_block_group(root->fs_info, last);
         if (!cache) {
                 return search_start;
         }
-        cache = btrfs_find_block_group(root, cache,
-                                       last + cache->key.offset - 1, data, 0);
+        cache = btrfs_find_block_group(root, cache, last, data, 0);
         *cache_ret = cache;
-        last = min(cache->key.objectid, last);
         goto again;
 }
 
@@ -257,12 +258,7 @@ struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
                 if (used < div_factor(hint->key.offset, factor)) {
                         return hint;
                 }
-                last = hint->key.offset * 3;
-                if (hint->key.objectid >= last)
-                        last = max(search_start + hint->key.offset - 1,
-                                   hint->key.objectid - last);
-                else
-                        last = hint->key.objectid + hint->key.offset;
+                last = hint->key.objectid + hint->key.offset;
                 hint_last = last;
         } else {
                 if (hint)
@@ -913,7 +909,6 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
 check_failed:
         search_start = find_search_start(root, &block_group,
                                          search_start, total_needed, data);
-
         btrfs_init_path(path);
         ins->objectid = search_start;
         ins->offset = 0;
@@ -958,6 +953,9 @@ check_failed:
                                 continue;
                         if (ret < 0)
                                 goto error;
+
+                        search_start = max(search_start,
+                                           block_group->key.objectid);
                         if (!start_found) {
                                 ins->objectid = search_start;
                                 ins->offset = search_end - search_start;
@@ -967,6 +965,7 @@ check_failed:
                         ins->objectid = last_byte > search_start ?
                                         last_byte : search_start;
                         ins->offset = search_end - ins->objectid;
+                        BUG_ON(ins->objectid >= search_end);
                         goto check_pending;
                 }
                 btrfs_item_key_to_cpu(l, &key, slot);
@@ -998,7 +997,7 @@ check_failed:
                     block_group->key.offset) {
                         btrfs_release_path(root, path);
                         search_start = block_group->key.objectid +
-                                block_group->key.offset * 2;
+                                block_group->key.offset;
                         goto new_group;
                 }
 next:
@@ -1015,6 +1014,12 @@ check_pending:
         if (ins->objectid + num_bytes >= search_end)
                 goto enospc;
 
+        if (!full_scan && ins->objectid + num_bytes >= block_group->
+            key.objectid + block_group->key.offset) {
+                search_start = block_group->key.objectid +
+                        block_group->key.offset;
+                goto new_group;
+        }
         if (test_range_bit(&info->extent_ins, ins->objectid,
                            ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) {
                 search_start = ins->objectid + num_bytes;
@@ -1114,6 +1119,7 @@ int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                 set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
                                 ins->objectid + ins->offset - 1,
                                 EXTENT_LOCKED, GFP_NOFS);
+                WARN_ON(data == 1);
                 goto update_block;
         }
 
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 7ef3397a266d..e241699024da 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -981,7 +981,7 @@ int find_first_extent_bit(struct extent_map_tree *tree, u64 start,
         struct extent_state *state;
         int ret = 1;
 
-        write_lock_irq(&tree->lock);
+        read_lock_irq(&tree->lock);
         /*
          * this search will find all the extents that end after
          * our range starts.
@@ -993,7 +993,7 @@ int find_first_extent_bit(struct extent_map_tree *tree, u64 start,
 
         while(1) {
                 state = rb_entry(node, struct extent_state, rb_node);
-                if (state->state & bits) {
+                if (state->end >= start && (state->state & bits)) {
                         *start_ret = state->start;
                         *end_ret = state->end;
                         ret = 0;
@@ -1004,7 +1004,7 @@ int find_first_extent_bit(struct extent_map_tree *tree, u64 start,
                         break;
         }
 out:
-        write_unlock_irq(&tree->lock);
+        read_unlock_irq(&tree->lock);
         return ret;
 }
 EXPORT_SYMBOL(find_first_extent_bit);