btrfs-progs: check: repair inode nbytes in lowmem mode

After checking one entire inode item, we should get the actual
nbytes of the inode item.

Like original mode, repair_inode_nbytes_lowmem() sets nbytes in
struct btrfs_inode_item to the actual nbytes.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/cmds-check.c b/cmds-check.c
index 89e12c1..3c2f143 100644 (file)
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -2017,6 +2017,9 @@ static int process_one_leaf_v2(struct btrfs_root *root, struct btrfs_path *path,
 again:
        err |= check_inode_item(root, path, ext_ref);
 
+       /* modify cur since check_inode_item may change path */
+       cur = path->nodes[0];
+
        if (err & LAST_ITEM)
                goto out;
 
@@ -2364,6 +2367,7 @@ static int walk_down_tree_v2(struct btrfs_root *root, struct btrfs_path *path,
                        }
                        ret = process_one_leaf_v2(root, path, nrefs,
                                                  level, ext_ref);
+                       cur = path->nodes[*level];
                        break;
                } else {
                        ret = btrfs_check_node(root, NULL, cur);
@@ -4953,6 +4957,67 @@ static int check_file_extent(struct btrfs_root *root, struct btrfs_key *fkey,
 }
 
 /*
+ * Set inode item nbytes to @nbytes
+ *
+ * Returns  0     on success
+ * Returns  != 0  on error
+ */
+static int repair_inode_nbytes_lowmem(struct btrfs_root *root,
+                                     struct btrfs_path *path,
+                                     u64 ino, u64 nbytes)
+{
+       struct btrfs_trans_handle *trans;
+       struct btrfs_inode_item *ii;
+       struct btrfs_key key;
+       struct btrfs_key research_key;
+       int err = 0;
+       int ret;
+
+       btrfs_item_key_to_cpu(path->nodes[0], &research_key, path->slots[0]);
+
+       key.objectid = ino;
+       key.type = BTRFS_INODE_ITEM_KEY;
+       key.offset = 0;
+
+       trans = btrfs_start_transaction(root, 1);
+       if (IS_ERR(trans)) {
+               ret = PTR_ERR(trans);
+               err |= ret;
+               goto out;
+       }
+
+       btrfs_release_path(path);
+       ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+       if (ret > 0)
+               ret = -ENOENT;
+       if (ret) {
+               err |= ret;
+               goto fail;
+       }
+
+       ii = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                           struct btrfs_inode_item);
+       btrfs_set_inode_nbytes(path->nodes[0], ii, nbytes);
+       btrfs_mark_buffer_dirty(path->nodes[0]);
+fail:
+       btrfs_commit_transaction(trans, root);
+out:
+       if (ret)
+               error("failed to set nbytes in inode %llu root %llu",
+                     ino, root->root_key.objectid);
+       else
+               printf("Set nbytes in inode item %llu root %llu\n to %llu", ino,
+                      root->root_key.objectid, nbytes);
+
+       /* research path */
+       btrfs_release_path(path);
+       ret = btrfs_search_slot(NULL, root, &research_key, path, 0, 0);
+       err |= ret;
+
+       return err;
+}
+
+/*
  * Check INODE_ITEM and related ITEMs (the same inode number)
  * 1. check link count
  * 2. check inode ref/extref
@@ -5107,9 +5172,16 @@ out:
                }
 
                if (nbytes != extent_size) {
-                       err |= NBYTES_ERROR;
-                       error("root %llu INODE[%llu] nbytes(%llu) not equal to extent_size(%llu)",
-                             root->objectid, inode_id, nbytes, extent_size);
+                       if (repair)
+                               ret = repair_inode_nbytes_lowmem(root, path,
+                                                        inode_id, extent_size);
+                       if (!repair || ret) {
+                               err |= NBYTES_ERROR;
+                               error(
+       "root %llu INODE[%llu] nbytes %llu not equal to extent_size %llu",
+                                     root->objectid, inode_id, nbytes,
+                                     extent_size);
+                       }
                }
        }