Btrfs: make sure reserve_metadata_bytes doesn't leak out strange errors

[pandora-kernel.git] / fs / btrfs / extent-tree.c

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index d7031e7..4d08ed7 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3474,6 +3474,8 @@ again:
        if (ret < 0)
                goto out;
 
+       ret = 0;
+
        /*
         * So if we were overcommitted it's possible that somebody else flushed
         * out enough space and we simply didn't have enough space to reclaim,
@@ -3496,10 +3498,13 @@ again:
                goto out;
 
        ret = -EAGAIN;
-       if (trans || committed)
+       if (trans)
                goto out;
 
        ret = -ENOSPC;
+       if (committed)
+               goto out;
+
        trans = btrfs_join_transaction(root);
        if (IS_ERR(trans))
                goto out;
@@ -5625,7 +5630,7 @@ struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans,
        if (!buf)
                return ERR_PTR(-ENOMEM);
        btrfs_set_header_generation(buf, trans->transid);
-       btrfs_set_buffer_lockdep_class(buf, level);
+       btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
        btrfs_tree_lock(buf);
        clean_tree_block(trans, root, buf);
 
@@ -5912,7 +5917,7 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
                        return 1;
 
                if (path->locks[level] && !wc->keep_locks) {
-                       btrfs_tree_unlock(eb);
+                       btrfs_tree_unlock_rw(eb, path->locks[level]);
                        path->locks[level] = 0;
                }
                return 0;
@@ -5936,7 +5941,7 @@ static noinline int walk_down_proc(struct btrfs_trans_handle *trans,
         * keep the tree lock
         */
        if (path->locks[level] && level > 0) {
-               btrfs_tree_unlock(eb);
+               btrfs_tree_unlock_rw(eb, path->locks[level]);
                path->locks[level] = 0;
        }
        return 0;
@@ -6049,7 +6054,7 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
        BUG_ON(level != btrfs_header_level(next));
        path->nodes[level] = next;
        path->slots[level] = 0;
-       path->locks[level] = 1;
+       path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
        wc->level = level;
        if (wc->level == 1)
                wc->reada_slot = 0;
@@ -6120,7 +6125,7 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
                        BUG_ON(level == 0);
                        btrfs_tree_lock(eb);
                        btrfs_set_lock_blocking(eb);
-                       path->locks[level] = 1;
+                       path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
 
                        ret = btrfs_lookup_extent_info(trans, root,
                                                       eb->start, eb->len,
@@ -6129,8 +6134,7 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
                        BUG_ON(ret);
                        BUG_ON(wc->refs[level] == 0);
                        if (wc->refs[level] == 1) {
-                               btrfs_tree_unlock(eb);
-                               path->locks[level] = 0;
+                               btrfs_tree_unlock_rw(eb, path->locks[level]);
                                return 1;
                        }
                }
@@ -6152,7 +6156,7 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
                    btrfs_header_generation(eb) == trans->transid) {
                        btrfs_tree_lock(eb);
                        btrfs_set_lock_blocking(eb);
-                       path->locks[level] = 1;
+                       path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
                }
                clean_tree_block(trans, root, eb);
        }
@@ -6231,7 +6235,8 @@ static noinline int walk_up_tree(struct btrfs_trans_handle *trans,
                                return 0;
 
                        if (path->locks[level]) {
-                               btrfs_tree_unlock(path->nodes[level]);
+                               btrfs_tree_unlock_rw(path->nodes[level],
+                                                    path->locks[level]);
                                path->locks[level] = 0;
                        }
                        free_extent_buffer(path->nodes[level]);
@@ -6283,7 +6288,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root,
                path->nodes[level] = btrfs_lock_root_node(root);
                btrfs_set_lock_blocking(path->nodes[level]);
                path->slots[level] = 0;
-               path->locks[level] = 1;
+               path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
                memset(&wc->update_progress, 0,
                       sizeof(wc->update_progress));
        } else {
@@ -6451,7 +6456,7 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
        level = btrfs_header_level(node);
        path->nodes[level] = node;
        path->slots[level] = 0;
-       path->locks[level] = 1;
+       path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING;
 
        wc->refs[parent_level] = 1;
        wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF;
@@ -6526,15 +6531,28 @@ static u64 update_block_group_flags(struct btrfs_root *root, u64 flags)
        return flags;
 }
 
-static int set_block_group_ro(struct btrfs_block_group_cache *cache)
+static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
 {
        struct btrfs_space_info *sinfo = cache->space_info;
        u64 num_bytes;
+       u64 min_allocable_bytes;
        int ret = -ENOSPC;
 
        if (cache->ro)
                return 0;
 
+       /*
+        * We need some metadata space and system metadata space for
+        * allocating chunks in some corner cases until we force to set
+        * it to be readonly.
+        */
+       if ((sinfo->flags &
+            (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) &&
+           !force)
+               min_allocable_bytes = 1 * 1024 * 1024;
+       else
+               min_allocable_bytes = 0;
+
        spin_lock(&sinfo->lock);
        spin_lock(&cache->lock);
        num_bytes = cache->key.offset - cache->reserved - cache->pinned -
@@ -6542,7 +6560,8 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache)
 
        if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned +
            sinfo->bytes_may_use + sinfo->bytes_readonly +
-           cache->reserved_pinned + num_bytes <= sinfo->total_bytes) {
+           cache->reserved_pinned + num_bytes + min_allocable_bytes <=
+           sinfo->total_bytes) {
                sinfo->bytes_readonly += num_bytes;
                sinfo->bytes_reserved += cache->reserved_pinned;
                cache->reserved_pinned = 0;
@@ -6573,7 +6592,7 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
                do_chunk_alloc(trans, root, 2 * 1024 * 1024, alloc_flags,
                               CHUNK_ALLOC_FORCE);
 
-       ret = set_block_group_ro(cache);
+       ret = set_block_group_ro(cache, 0);
        if (!ret)
                goto out;
        alloc_flags = get_alloc_profile(root, cache->space_info->flags);
@@ -6581,7 +6600,7 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
                             CHUNK_ALLOC_FORCE);
        if (ret < 0)
                goto out;
-       ret = set_block_group_ro(cache);
+       ret = set_block_group_ro(cache, 0);
 out:
        btrfs_end_transaction(trans, root);
        return ret;
@@ -7018,7 +7037,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
 
                set_avail_alloc_bits(root->fs_info, cache->flags);
                if (btrfs_chunk_readonly(root, cache->key.objectid))
-                       set_block_group_ro(cache);
+                       set_block_group_ro(cache, 1);
        }
 
        list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) {
@@ -7032,9 +7051,9 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                 * mirrored block groups.
                 */
                list_for_each_entry(cache, &space_info->block_groups[3], list)
-                       set_block_group_ro(cache);
+                       set_block_group_ro(cache, 1);
                list_for_each_entry(cache, &space_info->block_groups[4], list)
-                       set_block_group_ro(cache);
+                       set_block_group_ro(cache, 1);
        }
 
        init_global_block_rsv(info);