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

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

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0b0c947..72e6b27 100644 (file)
--- 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 7ef3397..e241699 100644 (file)
--- 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);