Btrfs: Metadata ENOSPC handling for tree log

Previous patches make the allocater return -ENOSPC if there is no
unreserved free metadata space. This patch updates tree log code
and various other places to propagate/handle the ENOSPC error.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 151 insertions, 90 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index af57dd2b43d4..fb102a9aee9c 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -135,6 +135,7 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root)
 {
         int ret;
+        int err = 0;
 
         mutex_lock(&root->log_mutex);
         if (root->log_root) {
@@ -155,17 +156,19 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
         mutex_lock(&root->fs_info->tree_log_mutex);
         if (!root->fs_info->log_root_tree) {
                 ret = btrfs_init_log_root_tree(trans, root->fs_info);
-                BUG_ON(ret);
+                if (ret)
+                        err = ret;
         }
-        if (!root->log_root) {
+        if (err == 0 && !root->log_root) {
                 ret = btrfs_add_log_tree(trans, root);
-                BUG_ON(ret);
+                if (ret)
+                        err = ret;
         }
         mutex_unlock(&root->fs_info->tree_log_mutex);
         root->log_batch++;
         atomic_inc(&root->log_writers);
         mutex_unlock(&root->log_mutex);
-        return 0;
+        return err;
 }
 
 /*
@@ -376,7 +379,7 @@ insert:
                         BUG_ON(ret);
                 }
         } else if (ret) {
-                BUG();
+                return ret;
         }
         dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
                                         path->slots[0]);
@@ -1699,9 +1702,9 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 
                 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
 
-                wc->process_func(root, next, wc, ptr_gen);
-
                 if (*level == 1) {
+                        wc->process_func(root, next, wc, ptr_gen);
+
                         path->slots[*level]++;
                         if (wc->free) {
                                 btrfs_read_buffer(next, ptr_gen);
@@ -1734,35 +1737,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
         WARN_ON(*level < 0);
         WARN_ON(*level >= BTRFS_MAX_LEVEL);
 
-        if (path->nodes[*level] == root->node)
-                parent = path->nodes[*level];
-        else
-                parent = path->nodes[*level + 1];
-
-        bytenr = path->nodes[*level]->start;
-
-        blocksize = btrfs_level_size(root, *level);
-        root_owner = btrfs_header_owner(parent);
-        root_gen = btrfs_header_generation(parent);
-
-        wc->process_func(root, path->nodes[*level], wc,
-                         btrfs_header_generation(path->nodes[*level]));
-
-        if (wc->free) {
-                next = path->nodes[*level];
-                btrfs_tree_lock(next);
-                clean_tree_block(trans, root, next);
-                btrfs_set_lock_blocking(next);
-                btrfs_wait_tree_block_writeback(next);
-                btrfs_tree_unlock(next);
-
-                WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
-                ret = btrfs_free_reserved_extent(root, bytenr, blocksize);
-                BUG_ON(ret);
-        }
-        free_extent_buffer(path->nodes[*level]);
-        path->nodes[*level] = NULL;
-        *level += 1;
+        path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
 
         cond_resched();
         return 0;
@@ -1781,7 +1756,7 @@ static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
 
         for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
                 slot = path->slots[i];
-                if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
+                if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
                         struct extent_buffer *node;
                         node = path->nodes[i];
                         path->slots[i]++;
@@ -2047,7 +2022,6 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
         mutex_unlock(&log_root_tree->log_mutex);
 
         ret = update_log_root(trans, log);
-        BUG_ON(ret);
 
         mutex_lock(&log_root_tree->log_mutex);
         if (atomic_dec_and_test(&log_root_tree->log_writers)) {
@@ -2056,6 +2030,15 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
                         wake_up(&log_root_tree->log_writer_wait);
         }
 
+        if (ret) {
+                BUG_ON(ret != -ENOSPC);
+                root->fs_info->last_trans_log_full_commit = trans->transid;
+                btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
+                mutex_unlock(&log_root_tree->log_mutex);
+                ret = -EAGAIN;
+                goto out;
+        }
+
         index2 = log_root_tree->log_transid % 2;
         if (atomic_read(&log_root_tree->log_commit[index2])) {
                 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
@@ -2129,15 +2112,10 @@ out:
         return 0;
 }
 
-/*
- * free all the extents used by the tree log.  This should be called
- * at commit time of the full transaction
- */
-int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
+static void free_log_tree(struct btrfs_trans_handle *trans,
+                          struct btrfs_root *log)
 {
         int ret;
-        struct btrfs_root *log;
-        struct key;
         u64 start;
         u64 end;
         struct walk_control wc = {
@@ -2145,10 +2123,6 @@ int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
                 .process_func = process_one_buffer
         };
 
-        if (!root->log_root || root->fs_info->log_root_recovering)
-                return 0;
-
-        log = root->log_root;
         ret = walk_log_tree(trans, log, &wc);
         BUG_ON(ret);
 
@@ -2162,14 +2136,30 @@ int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
                                   EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
         }
 
-        if (log->log_transid > 0) {
-                ret = btrfs_del_root(trans, root->fs_info->log_root_tree,
-                                     &log->root_key);
-                BUG_ON(ret);
-        }
-        root->log_root = NULL;
         free_extent_buffer(log->node);
         kfree(log);
+}
+
+/*
+ * free all the extents used by the tree log.  This should be called
+ * at commit time of the full transaction
+ */
+int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
+{
+        if (root->log_root) {
+                free_log_tree(trans, root->log_root);
+                root->log_root = NULL;
+        }
+        return 0;
+}
+
+int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
+                             struct btrfs_fs_info *fs_info)
+{
+        if (fs_info->log_root_tree) {
+                free_log_tree(trans, fs_info->log_root_tree);
+                fs_info->log_root_tree = NULL;
+        }
         return 0;
 }
 
@@ -2203,6 +2193,7 @@ int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
         struct btrfs_dir_item *di;
         struct btrfs_path *path;
         int ret;
+        int err = 0;
         int bytes_del = 0;
 
         if (BTRFS_I(dir)->logged_trans < trans->transid)
@@ -2218,7 +2209,11 @@ int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
         path = btrfs_alloc_path();
         di = btrfs_lookup_dir_item(trans, log, path, dir->i_ino,
                                    name, name_len, -1);
-        if (di && !IS_ERR(di)) {
+        if (IS_ERR(di)) {
+                err = PTR_ERR(di);
+                goto fail;
+        }
+        if (di) {
                 ret = btrfs_delete_one_dir_name(trans, log, path, di);
                 bytes_del += name_len;
                 BUG_ON(ret);
@@ -2226,7 +2221,11 @@ int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
         btrfs_release_path(log, path);
         di = btrfs_lookup_dir_index_item(trans, log, path, dir->i_ino,
                                          index, name, name_len, -1);
-        if (di && !IS_ERR(di)) {
+        if (IS_ERR(di)) {
+                err = PTR_ERR(di);
+                goto fail;
+        }
+        if (di) {
                 ret = btrfs_delete_one_dir_name(trans, log, path, di);
                 bytes_del += name_len;
                 BUG_ON(ret);
@@ -2244,6 +2243,10 @@ int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
                 btrfs_release_path(log, path);
 
                 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
+                if (ret < 0) {
+                        err = ret;
+                        goto fail;
+                }
                 if (ret == 0) {
                         struct btrfs_inode_item *item;
                         u64 i_size;
@@ -2261,9 +2264,13 @@ int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
                         ret = 0;
                 btrfs_release_path(log, path);
         }
-
+fail:
         btrfs_free_path(path);
         mutex_unlock(&BTRFS_I(dir)->log_mutex);
+        if (ret == -ENOSPC) {
+                root->fs_info->last_trans_log_full_commit = trans->transid;
+                ret = 0;
+        }
         btrfs_end_log_trans(root);
 
         return 0;
@@ -2291,6 +2298,10 @@ int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
         ret = btrfs_del_inode_ref(trans, log, name, name_len, inode->i_ino,
                                   dirid, &index);
         mutex_unlock(&BTRFS_I(inode)->log_mutex);
+        if (ret == -ENOSPC) {
+                root->fs_info->last_trans_log_full_commit = trans->transid;
+                ret = 0;
+        }
         btrfs_end_log_trans(root);
 
         return ret;
@@ -2318,7 +2329,8 @@ static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
         else
                 key.type = BTRFS_DIR_LOG_INDEX_KEY;
         ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
-        BUG_ON(ret);
+        if (ret)
+                return ret;
 
         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
                               struct btrfs_dir_log_item);
@@ -2343,6 +2355,7 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans,
         struct btrfs_key max_key;
         struct btrfs_root *log = root->log_root;
         struct extent_buffer *src;
+        int err = 0;
         int ret;
         int i;
         int nritems;
@@ -2405,6 +2418,10 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans,
                         ret = overwrite_item(trans, log, dst_path,
                                              path->nodes[0], path->slots[0],
                                              &tmp);
+                        if (ret) {
+                                err = ret;
+                                goto done;
+                        }
                 }
         }
         btrfs_release_path(root, path);
@@ -2432,7 +2449,10 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans,
                                 goto done;
                         ret = overwrite_item(trans, log, dst_path, src, i,
                                              &min_key);
-                        BUG_ON(ret);
+                        if (ret) {
+                                err = ret;
+                                goto done;
+                        }
                 }
                 path->slots[0] = nritems;
 
@@ -2454,22 +2474,30 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans,
                         ret = overwrite_item(trans, log, dst_path,
                                              path->nodes[0], path->slots[0],
                                              &tmp);
-
-                        BUG_ON(ret);
-                        last_offset = tmp.offset;
+                        if (ret)
+                                err = ret;
+                        else
+                                last_offset = tmp.offset;
                         goto done;
                 }
         }
 done:
-        *last_offset_ret = last_offset;
         btrfs_release_path(root, path);
         btrfs_release_path(log, dst_path);
 
-        /* insert the log range keys to indicate where the log is valid */
-        ret = insert_dir_log_key(trans, log, path, key_type, inode->i_ino,
-                                 first_offset, last_offset);
-        BUG_ON(ret);
-        return 0;
+        if (err == 0) {
+                *last_offset_ret = last_offset;
+                /*
+                 * insert the log range keys to indicate where the log
+                 * is valid
+                 */
+                ret = insert_dir_log_key(trans, log, path, key_type,
+                                         inode->i_ino, first_offset,
+                                         last_offset);
+                if (ret)
+                        err = ret;
+        }
+        return err;
 }
 
 /*
@@ -2501,7 +2529,8 @@ again:
                 ret = log_dir_items(trans, root, inode, path,
                                     dst_path, key_type, min_key,
                                     &max_key);
-                BUG_ON(ret);
+                if (ret)
+                        return ret;
                 if (max_key == (u64)-1)
                         break;
                 min_key = max_key + 1;
@@ -2535,8 +2564,8 @@ static int drop_objectid_items(struct btrfs_trans_handle *trans,
 
         while (1) {
                 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
-
-                if (ret != 1)
+                BUG_ON(ret == 0);
+                if (ret < 0)
                         break;
 
                 if (path->slots[0] == 0)
@@ -2554,7 +2583,7 @@ static int drop_objectid_items(struct btrfs_trans_handle *trans,
                 btrfs_release_path(log, path);
         }
         btrfs_release_path(log, path);
-        return 0;
+        return ret;
 }
 
 static noinline int copy_items(struct btrfs_trans_handle *trans,
@@ -2587,7 +2616,10 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
         }
         ret = btrfs_insert_empty_items(trans, log, dst_path,
                                        ins_keys, ins_sizes, nr);
-        BUG_ON(ret);
+        if (ret) {
+                kfree(ins_data);
+                return ret;
+        }
 
         for (i = 0; i < nr; i++, dst_path->slots[0]++) {
                 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
@@ -2660,16 +2692,17 @@ static noinline int copy_items(struct btrfs_trans_handle *trans,
          * we have to do this after the loop above to avoid changing the
          * log tree while trying to change the log tree.
          */
+        ret = 0;
         while (!list_empty(&ordered_sums)) {
                 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
                                                    struct btrfs_ordered_sum,
                                                    list);
-                ret = btrfs_csum_file_blocks(trans, log, sums);
-                BUG_ON(ret);
+                if (!ret)
+                        ret = btrfs_csum_file_blocks(trans, log, sums);
                 list_del(&sums->list);
                 kfree(sums);
         }
-        return 0;
+        return ret;
 }
 
 /* log a single inode in the tree log.
@@ -2697,6 +2730,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
         struct btrfs_root *log = root->log_root;
         struct extent_buffer *src = NULL;
         u32 size;
+        int err = 0;
         int ret;
         int nritems;
         int ins_start_slot = 0;
@@ -2739,7 +2773,10 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans,
         } else {
                 ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0);
         }
-        BUG_ON(ret);
+        if (ret) {
+                err = ret;
+                goto out_unlock;
+        }
         path->keep_locks = 1;
 
         while (1) {
@@ -2768,7 +2805,10 @@ again:
 
                 ret = copy_items(trans, log, dst_path, src, ins_start_slot,
                                  ins_nr, inode_only);
-                BUG_ON(ret);
+                if (ret) {
+                        err = ret;
+                        goto out_unlock;
+                }
                 ins_nr = 1;
                 ins_start_slot = path->slots[0];
 next_slot:
@@ -2784,7 +2824,10 @@ next_slot:
                         ret = copy_items(trans, log, dst_path, src,
                                          ins_start_slot,
                                          ins_nr, inode_only);
-                        BUG_ON(ret);
+                        if (ret) {
+                                err = ret;
+                                goto out_unlock;
+                        }
                         ins_nr = 0;
                 }
                 btrfs_release_path(root, path);
@@ -2802,7 +2845,10 @@ next_slot:
                 ret = copy_items(trans, log, dst_path, src,
                                  ins_start_slot,
                                  ins_nr, inode_only);
-                BUG_ON(ret);
+                if (ret) {
+                        err = ret;
+                        goto out_unlock;
+                }
                 ins_nr = 0;
         }
         WARN_ON(ins_nr);
@@ -2810,14 +2856,18 @@ next_slot:
                 btrfs_release_path(root, path);
                 btrfs_release_path(log, dst_path);
                 ret = log_directory_changes(trans, root, inode, path, dst_path);
-                BUG_ON(ret);
+                if (ret) {
+                        err = ret;
+                        goto out_unlock;
+                }
         }
         BTRFS_I(inode)->logged_trans = trans->transid;
+out_unlock:
         mutex_unlock(&BTRFS_I(inode)->log_mutex);
 
         btrfs_free_path(path);
         btrfs_free_path(dst_path);
-        return 0;
+        return err;
 }
 
 /*
@@ -2942,10 +2992,13 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
                 goto end_no_trans;
         }
 
-        start_log_trans(trans, root);
+        ret = start_log_trans(trans, root);
+        if (ret)
+                goto end_trans;
 
         ret = btrfs_log_inode(trans, root, inode, inode_only);
-        BUG_ON(ret);
+        if (ret)
+                goto end_trans;
 
         /*
          * for regular files, if its inode is already on disk, we don't
@@ -2955,8 +3008,10 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
          */
         if (S_ISREG(inode->i_mode) &&
             BTRFS_I(inode)->generation <= last_committed &&
-            BTRFS_I(inode)->last_unlink_trans <= last_committed)
-                        goto no_parent;
+            BTRFS_I(inode)->last_unlink_trans <= last_committed) {
+                ret = 0;
+                goto end_trans;
+        }
 
         inode_only = LOG_INODE_EXISTS;
         while (1) {
@@ -2970,15 +3025,21 @@ int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
                 if (BTRFS_I(inode)->generation >
                     root->fs_info->last_trans_committed) {
                         ret = btrfs_log_inode(trans, root, inode, inode_only);
-                        BUG_ON(ret);
+                        if (ret)
+                                goto end_trans;
                 }
                 if (IS_ROOT(parent))
                         break;
 
                 parent = parent->d_parent;
         }
-no_parent:
         ret = 0;
+end_trans:
+        if (ret < 0) {
+                BUG_ON(ret != -ENOSPC);
+                root->fs_info->last_trans_log_full_commit = trans->transid;
+                ret = 1;
+        }
         btrfs_end_log_trans(root);
 end_no_trans:
         return ret;
@@ -3020,7 +3081,7 @@ int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
         path = btrfs_alloc_path();
         BUG_ON(!path);
 
-        trans = btrfs_start_transaction(fs_info->tree_root, 1);
+        trans = btrfs_start_transaction(fs_info->tree_root, 0);
 
         wc.trans = trans;
         wc.pin = 1;