Hi,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on v5.12-rc2]
[also build test WARNING on next-20210311]
[cannot apply to kdave/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/fdmanana-kernel-org/btrfs-bug-fixes-for-the-tree-mod-log-and-small-refactorings/20210311-223429
base:    a38fd8748464831584a19438cbb3082b5a2dab15
config: x86_64-randconfig-m001-20210311 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

smatch warnings:
fs/btrfs/tree-mod-log.c:286 btrfs_tree_mod_log_insert_move() warn: missing error code 'ret'
fs/btrfs/tree-mod-log.c:519 btrfs_tree_mod_log_eb_copy() warn: missing error code 'ret'
fs/btrfs/tree-mod-log.c:577 btrfs_tree_mod_log_free_eb() warn: missing error code 'ret'

vim +/ret +286 fs/btrfs/tree-mod-log.c

   246	
   247	int btrfs_tree_mod_log_insert_move(struct extent_buffer *eb,
   248					   int dst_slot, int src_slot,
   249					   int nr_items)
   250	{
   251		struct tree_mod_elem *tm = NULL;
   252		struct tree_mod_elem **tm_list = NULL;
   253		int ret = 0;
   254		int i;
   255		int locked = 0;
   256	
   257		if (!tree_mod_need_log(eb->fs_info, eb))
   258			return 0;
   259	
   260		tm_list = kcalloc(nr_items, sizeof(struct tree_mod_elem *), GFP_NOFS);
   261		if (!tm_list)
   262			return -ENOMEM;
   263	
   264		tm = kzalloc(sizeof(*tm), GFP_NOFS);
   265		if (!tm) {
   266			ret = -ENOMEM;
   267			goto free_tms;
   268		}
   269	
   270		tm->logical = eb->start;
   271		tm->slot = src_slot;
   272		tm->move.dst_slot = dst_slot;
   273		tm->move.nr_items = nr_items;
   274		tm->op = BTRFS_MOD_LOG_MOVE_KEYS;
   275	
   276		for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) {
   277			tm_list[i] = alloc_tree_mod_elem(eb, i + dst_slot,
   278			    BTRFS_MOD_LOG_KEY_REMOVE_WHILE_MOVING, GFP_NOFS);
   279			if (!tm_list[i]) {
   280				ret = -ENOMEM;
   281				goto free_tms;
   282			}
   283		}
   284	
   285		if (tree_mod_dont_log(eb->fs_info, eb))
 > 286			goto free_tms;
   287		locked = 1;
   288	
   289		/*
   290		 * When we override something during the move, we log these removals.
   291		 * This can only happen when we move towards the beginning of the
   292		 * buffer, i.e. dst_slot < src_slot.
   293		 */
   294		for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) {
   295			ret = tree_mod_log_insert(eb->fs_info, tm_list[i]);
   296			if (ret)
   297				goto free_tms;
   298		}
   299	
   300		ret = tree_mod_log_insert(eb->fs_info, tm);
   301		if (ret)
   302			goto free_tms;
   303		write_unlock(&eb->fs_info->tree_mod_log_lock);
   304		kfree(tm_list);
   305	
   306		return 0;
   307	free_tms:
   308		for (i = 0; i < nr_items; i++) {
   309			if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node))
   310				rb_erase(&tm_list[i]->node, &eb->fs_info->tree_mod_log);
   311			kfree(tm_list[i]);
   312		}
   313		if (locked)
   314			write_unlock(&eb->fs_info->tree_mod_log_lock);
   315		kfree(tm_list);
   316		kfree(tm);
   317	
   318		return ret;
   319	}
   320	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org