1 files changed, 155 insertions, 35 deletions

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index fb5cd5a4adba..5a4999aa8fef 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -31,7 +31,7 @@
 
 #define BTRFS_ROOT_TRANS_TAG 0
 
-static noinline void put_transaction(struct btrfs_transaction *transaction)
+void put_transaction(struct btrfs_transaction *transaction)
 {
         WARN_ON(atomic_read(&transaction->use_count) == 0);
         if (atomic_dec_and_test(&transaction->use_count)) {
@@ -58,6 +58,12 @@ static noinline int join_transaction(struct btrfs_root *root, int nofail)
 
         spin_lock(&root->fs_info->trans_lock);
 loop:
+        /* The file system has been taken offline. No new transactions. */
+        if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+                spin_unlock(&root->fs_info->trans_lock);
+                return -EROFS;
+        }
+
         if (root->fs_info->trans_no_join) {
                 if (!nofail) {
                         spin_unlock(&root->fs_info->trans_lock);
@@ -67,6 +73,8 @@ loop:
 
         cur_trans = root->fs_info->running_transaction;
         if (cur_trans) {
+                if (cur_trans->aborted)
+                        return cur_trans->aborted;
                 atomic_inc(&cur_trans->use_count);
                 atomic_inc(&cur_trans->num_writers);
                 cur_trans->num_joined++;
@@ -123,6 +131,7 @@ loop:
         root->fs_info->generation++;
         cur_trans->transid = root->fs_info->generation;
         root->fs_info->running_transaction = cur_trans;
+        cur_trans->aborted = 0;
         spin_unlock(&root->fs_info->trans_lock);
 
         return 0;
@@ -318,6 +327,7 @@ again:
         h->use_count = 1;
         h->block_rsv = NULL;
         h->orig_rsv = NULL;
+        h->aborted = 0;
 
         smp_mb();
         if (cur_trans->blocked && may_wait_transaction(root, type)) {
@@ -440,6 +450,7 @@ int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
         struct btrfs_transaction *cur_trans = trans->transaction;
         struct btrfs_block_rsv *rsv = trans->block_rsv;
         int updates;
+        int err;
 
         smp_mb();
         if (cur_trans->blocked || cur_trans->delayed_refs.flushing)
@@ -453,8 +464,11 @@ int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
 
         updates = trans->delayed_ref_updates;
         trans->delayed_ref_updates = 0;
-        if (updates)
-                btrfs_run_delayed_refs(trans, root, updates);
+        if (updates) {
+                err = btrfs_run_delayed_refs(trans, root, updates);
+                if (err) /* Error code will also eval true */
+                        return err;
+        }
 
         trans->block_rsv = rsv;
 
@@ -525,6 +539,11 @@ static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
         if (throttle)
                 btrfs_run_delayed_iputs(root);
 
+        if (trans->aborted ||
+            root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+                return -EIO;
+        }
+
         return 0;
 }
 
@@ -690,11 +709,13 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
                 ret = btrfs_update_root(trans, tree_root,
                                         &root->root_key,
                                         &root->root_item);
-                BUG_ON(ret);
+                if (ret)
+                        return ret;
 
                 old_root_used = btrfs_root_used(&root->root_item);
                 ret = btrfs_write_dirty_block_groups(trans, root);
-                BUG_ON(ret);
+                if (ret)
+                        return ret;
         }
 
         if (root != root->fs_info->extent_root)
@@ -705,6 +726,10 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
 
 /*
  * update all the cowonly tree roots on disk
+ *
+ * The error handling in this function may not be obvious. Any of the
+ * failures will cause the file system to go offline. We still need
+ * to clean up the delayed refs.
  */
 static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
                                          struct btrfs_root *root)
@@ -715,22 +740,30 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
         int ret;
 
         ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
-        BUG_ON(ret);
+        if (ret)
+                return ret;
 
         eb = btrfs_lock_root_node(fs_info->tree_root);
-        btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
+        ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
+                              0, &eb);
         btrfs_tree_unlock(eb);
         free_extent_buffer(eb);
 
+        if (ret)
+                return ret;
+
         ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
-        BUG_ON(ret);
+        if (ret)
+                return ret;
 
         while (!list_empty(&fs_info->dirty_cowonly_roots)) {
                 next = fs_info->dirty_cowonly_roots.next;
                 list_del_init(next);
                 root = list_entry(next, struct btrfs_root, dirty_list);
 
-                update_cowonly_root(trans, root);
+                ret = update_cowonly_root(trans, root);
+                if (ret)
+                        return ret;
         }
 
         down_write(&fs_info->extent_commit_sem);
@@ -874,7 +907,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 
         new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
         if (!new_root_item) {
-                pending->error = -ENOMEM;
+                ret = pending->error = -ENOMEM;
                 goto fail;
         }
 
@@ -911,7 +944,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
          * insert the directory item
          */
         ret = btrfs_set_inode_index(parent_inode, &index);
-        BUG_ON(ret);
+        BUG_ON(ret); /* -ENOMEM */
         ret = btrfs_insert_dir_item(trans, parent_root,
                                 dentry->d_name.name, dentry->d_name.len,
                                 parent_inode, &key,
@@ -920,12 +953,14 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
                 pending->error = -EEXIST;
                 dput(parent);
                 goto fail;
-        }
+        } else if (ret)
+                goto abort_trans;
 
         btrfs_i_size_write(parent_inode, parent_inode->i_size +
                                          dentry->d_name.len * 2);
         ret = btrfs_update_inode(trans, parent_root, parent_inode);
-        BUG_ON(ret);
+        if (ret)
+                goto abort_trans;
 
         /*
          * pull in the delayed directory update
@@ -934,7 +969,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
          * snapshot
          */
         ret = btrfs_run_delayed_items(trans, root);
-        BUG_ON(ret);
+        if (ret) /* Transaction aborted */
+                goto fail;
 
         record_root_in_trans(trans, root);
         btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
@@ -949,10 +985,16 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         btrfs_set_root_flags(new_root_item, root_flags);
 
         old = btrfs_lock_root_node(root);
-        btrfs_cow_block(trans, root, old, NULL, 0, &old);
+        ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
+        if (ret)
+                goto abort_trans;
+
         btrfs_set_lock_blocking(old);
 
-        btrfs_copy_root(trans, root, old, &tmp, objectid);
+        ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
+        if (ret)
+                goto abort_trans;
+
         btrfs_tree_unlock(old);
         free_extent_buffer(old);
 
@@ -966,7 +1008,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
         ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
         btrfs_tree_unlock(tmp);
         free_extent_buffer(tmp);
-        BUG_ON(ret);
+        if (ret)
+                goto abort_trans;
 
         /*
          * insert root back/forward references
@@ -975,19 +1018,28 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
                                  parent_root->root_key.objectid,
                                  btrfs_ino(parent_inode), index,
                                  dentry->d_name.name, dentry->d_name.len);
-        BUG_ON(ret);
+        if (ret)
+                goto fail;
         dput(parent);
 
         key.offset = (u64)-1;
         pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
-        BUG_ON(IS_ERR(pending->snap));
+        if (IS_ERR(pending->snap))
+                goto abort_trans;
 
-        btrfs_reloc_post_snapshot(trans, pending);
+        ret = btrfs_reloc_post_snapshot(trans, pending);
+        if (ret)
+                goto abort_trans;
+        ret = 0;
 fail:
         kfree(new_root_item);
         trans->block_rsv = rsv;
         btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1);
-        return 0;
+        return ret;
+
+abort_trans:
+        btrfs_abort_transaction(trans, root, ret);
+        goto fail;
 }
 
 /*
@@ -1124,6 +1176,33 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
         return 0;
 }
 
+
+static void cleanup_transaction(struct btrfs_trans_handle *trans,
+                                struct btrfs_root *root)
+{
+        struct btrfs_transaction *cur_trans = trans->transaction;
+
+        WARN_ON(trans->use_count > 1);
+
+        spin_lock(&root->fs_info->trans_lock);
+        list_del_init(&cur_trans->list);
+        spin_unlock(&root->fs_info->trans_lock);
+
+        btrfs_cleanup_one_transaction(trans->transaction, root);
+
+        put_transaction(cur_trans);
+        put_transaction(cur_trans);
+
+        trace_btrfs_transaction_commit(root);
+
+        btrfs_scrub_continue(root);
+
+        if (current->journal_info == trans)
+                current->journal_info = NULL;
+
+        kmem_cache_free(btrfs_trans_handle_cachep, trans);
+}
+
 /*
  * btrfs_transaction state sequence:
  *    in_commit = 0, blocked = 0  (initial)
@@ -1135,10 +1214,10 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root)
 {
         unsigned long joined = 0;
-        struct btrfs_transaction *cur_trans;
+        struct btrfs_transaction *cur_trans = trans->transaction;
         struct btrfs_transaction *prev_trans = NULL;
         DEFINE_WAIT(wait);
-        int ret;
+        int ret = -EIO;
         int should_grow = 0;
         unsigned long now = get_seconds();
         int flush_on_commit = btrfs_test_opt(root, FLUSHONCOMMIT);
@@ -1148,13 +1227,18 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         btrfs_trans_release_metadata(trans, root);
         trans->block_rsv = NULL;
 
+        if (cur_trans->aborted)
+                goto cleanup_transaction;
+
         /* make a pass through all the delayed refs we have so far
          * any runnings procs may add more while we are here
          */
         ret = btrfs_run_delayed_refs(trans, root, 0);
-        BUG_ON(ret);
+        if (ret)
+                goto cleanup_transaction;
 
         cur_trans = trans->transaction;
+
         /*
          * set the flushing flag so procs in this transaction have to
          * start sending their work down.
@@ -1162,19 +1246,20 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         cur_trans->delayed_refs.flushing = 1;
 
         ret = btrfs_run_delayed_refs(trans, root, 0);
-        BUG_ON(ret);
+        if (ret)
+                goto cleanup_transaction;
 
         spin_lock(&cur_trans->commit_lock);
         if (cur_trans->in_commit) {
                 spin_unlock(&cur_trans->commit_lock);
                 atomic_inc(&cur_trans->use_count);
-                btrfs_end_transaction(trans, root);
+                ret = btrfs_end_transaction(trans, root);
 
                 wait_for_commit(root, cur_trans);
 
                 put_transaction(cur_trans);
 
-                return 0;
+                return ret;
         }
 
         trans->transaction->in_commit = 1;
@@ -1218,7 +1303,8 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                 }
 
                 ret = btrfs_run_delayed_items(trans, root);
-                BUG_ON(ret);
+                if (ret)
+                        goto cleanup_transaction;
 
                 /*
                  * rename don't use btrfs_join_transaction, so, once we
@@ -1260,13 +1346,22 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         mutex_lock(&root->fs_info->reloc_mutex);
 
         ret = btrfs_run_delayed_items(trans, root);
-        BUG_ON(ret);
+        if (ret) {
+                mutex_unlock(&root->fs_info->reloc_mutex);
+                goto cleanup_transaction;
+        }
 
         ret = create_pending_snapshots(trans, root->fs_info);
-        BUG_ON(ret);
+        if (ret) {
+                mutex_unlock(&root->fs_info->reloc_mutex);
+                goto cleanup_transaction;
+        }
 
         ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
-        BUG_ON(ret);
+        if (ret) {
+                mutex_unlock(&root->fs_info->reloc_mutex);
+                goto cleanup_transaction;
+        }
 
         /*
          * make sure none of the code above managed to slip in a
@@ -1293,7 +1388,10 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         mutex_lock(&root->fs_info->tree_log_mutex);
 
         ret = commit_fs_roots(trans, root);
-        BUG_ON(ret);
+        if (ret) {
+                mutex_unlock(&root->fs_info->tree_log_mutex);
+                goto cleanup_transaction;
+        }
 
         /* commit_fs_roots gets rid of all the tree log roots, it is now
          * safe to free the root of tree log roots
@@ -1301,7 +1399,10 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         btrfs_free_log_root_tree(trans, root->fs_info);
 
         ret = commit_cowonly_roots(trans, root);
-        BUG_ON(ret);
+        if (ret) {
+                mutex_unlock(&root->fs_info->tree_log_mutex);
+                goto cleanup_transaction;
+        }
 
         btrfs_prepare_extent_commit(trans, root);
 
@@ -1335,8 +1436,18 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         wake_up(&root->fs_info->transaction_wait);
 
         ret = btrfs_write_and_wait_transaction(trans, root);
-        BUG_ON(ret);
-        write_ctree_super(trans, root, 0);
+        if (ret) {
+                btrfs_error(root->fs_info, ret,
+                            "Error while writing out transaction.");
+                mutex_unlock(&root->fs_info->tree_log_mutex);
+                goto cleanup_transaction;
+        }
+
+        ret = write_ctree_super(trans, root, 0);
+        if (ret) {
+                mutex_unlock(&root->fs_info->tree_log_mutex);
+                goto cleanup_transaction;
+        }
 
         /*
          * the super is written, we can safely allow the tree-loggers
@@ -1372,6 +1483,15 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
                 btrfs_run_delayed_iputs(root);
 
         return ret;
+
+cleanup_transaction:
+        btrfs_printk(root->fs_info, "Skipping commit of aborted transaction.\n");
+//      WARN_ON(1);
+        if (current->journal_info == trans)
+                current->journal_info = NULL;
+        cleanup_transaction(trans, root);
+
+        return ret;
 }
 
 /*