tree: https://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux.git misc-next head: e19a1a28c0327556bc78e4c5081dab9d5e557f1a commit: 6105869e2ac5f5e4eeb3a7e2db001ce72a49df9a [3/4] btrfs: make fast fsyncs wait only for writeback compiler: or1k-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; cppcheck warnings: (new ones prefixed by >>) return ret; ^ fs/btrfs/tree-log.c:4476:6: note: first condition if (ret) ^ fs/btrfs/tree-log.c:4501:9: note: second condition return ret; ^ fs/btrfs/tree-log.c:2184:6: warning: Variable 'ret' is reassigned a value before the old one has been used. [redundantAssignment] ret = 0; ^ fs/btrfs/tree-log.c:2162:6: note: Variable 'ret' is reassigned a value before the old one has been used. ret = 1; ^ fs/btrfs/tree-log.c:2184:6: note: Variable 'ret' is reassigned a value before the old one has been used. ret = 0; ^ fs/btrfs/tree-log.c:3547:6: warning: Variable 'log' is reassigned a value before the old one has been used. [redundantAssignment] log = root->log_root; ^ fs/btrfs/tree-log.c:3537:0: note: Variable 'log' is reassigned a value before the old one has been used. struct btrfs_root *log = root->log_root; ^ fs/btrfs/tree-log.c:3547:6: note: Variable 'log' is reassigned a value before the old one has been used. log = root->log_root; ^ fs/btrfs/tree-log.c:5855:8: warning: Variable 'leaf' is reassigned a value before the old one has been used. [redundantAssignment] leaf = path->nodes[0]; ^ fs/btrfs/tree-log.c:5822:0: note: Variable 'leaf' is reassigned a value before the old one has been used. struct extent_buffer *leaf = path->nodes[0]; ^ fs/btrfs/tree-log.c:5855:8: note: Variable 'leaf' is reassigned a value before the old one has been used. leaf = path->nodes[0]; ^ fs/btrfs/tree-log.c:5856:8: warning: Variable 'slot' is reassigned a value before the old one has been used. [redundantAssignment] slot = path->slots[0]; ^ fs/btrfs/tree-log.c:5823:0: note: Variable 'slot' is reassigned a value before the old one has been used. int slot = path->slots[0]; ^ fs/btrfs/tree-log.c:5856:8: note: Variable 'slot' is reassigned a value before the old one has been used. slot = path->slots[0]; ^ # https://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux.git/commit... git remote add fdmanana https://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux.git git fetch --no-tags fdmanana misc-next git checkout 6105869e2ac5f5e4eeb3a7e2db001ce72a49df9a vim +/ret +4501 fs/btrfs/tree-log.c 31d11b83b96faa Filipe Manana 2018-05-09 4396 5dc562c541e102 Josef Bacik 2012-08-17 4397 static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, 5dc562c541e102 Josef Bacik 2012-08-17 4398 struct btrfs_root *root, 9d122629f1f65a Nikolay Borisov 2017-01-18 4399 struct btrfs_inode *inode, 827463c49f2911 Miao Xie 2014-01-14 4400 struct btrfs_path *path, 6105869e2ac5f5 Filipe Manana 2020-08-11 4401 struct btrfs_log_ctx *ctx) 5dc562c541e102 Josef Bacik 2012-08-17 4402 { 6105869e2ac5f5 Filipe Manana 2020-08-11 4403 struct btrfs_ordered_extent *ordered; 6105869e2ac5f5 Filipe Manana 2020-08-11 4404 struct btrfs_ordered_extent *tmp; 5dc562c541e102 Josef Bacik 2012-08-17 4405 struct extent_map *em, *n; 5dc562c541e102 Josef Bacik 2012-08-17 4406 struct list_head extents; 9d122629f1f65a Nikolay Borisov 2017-01-18 4407 struct extent_map_tree *tree = &inode->extent_tree; 5dc562c541e102 Josef Bacik 2012-08-17 4408 u64 test_gen; 5dc562c541e102 Josef Bacik 2012-08-17 4409 int ret = 0; 2ab28f322f9896 Josef Bacik 2012-10-12 4410 int num = 0; 5dc562c541e102 Josef Bacik 2012-08-17 4411 5dc562c541e102 Josef Bacik 2012-08-17 4412 INIT_LIST_HEAD(&extents); 5dc562c541e102 Josef Bacik 2012-08-17 4413 5dc562c541e102 Josef Bacik 2012-08-17 4414 write_lock(&tree->lock); 5dc562c541e102 Josef Bacik 2012-08-17 4415 test_gen = root->fs_info->last_trans_committed; 5dc562c541e102 Josef Bacik 2012-08-17 4416 5dc562c541e102 Josef Bacik 2012-08-17 4417 list_for_each_entry_safe(em, n, &tree->modified_extents, list) { 5dc562c541e102 Josef Bacik 2012-08-17 4418 list_del_init(&em->list); 2ab28f322f9896 Josef Bacik 2012-10-12 4419 /* 2ab28f322f9896 Josef Bacik 2012-10-12 4420 * Just an arbitrary number, this can be really CPU intensive 2ab28f322f9896 Josef Bacik 2012-10-12 4421 * once we start getting a lot of extents, and really once we 2ab28f322f9896 Josef Bacik 2012-10-12 4422 * have a bunch of extents we just want to commit since it will 2ab28f322f9896 Josef Bacik 2012-10-12 4423 * be faster. 2ab28f322f9896 Josef Bacik 2012-10-12 4424 */ 2ab28f322f9896 Josef Bacik 2012-10-12 4425 if (++num > 32768) { 2ab28f322f9896 Josef Bacik 2012-10-12 4426 list_del_init(&tree->modified_extents); 2ab28f322f9896 Josef Bacik 2012-10-12 4427 ret = -EFBIG; 2ab28f322f9896 Josef Bacik 2012-10-12 4428 goto process; 2ab28f322f9896 Josef Bacik 2012-10-12 4429 } 2ab28f322f9896 Josef Bacik 2012-10-12 4430 5dc562c541e102 Josef Bacik 2012-08-17 4431 if (em->generation <= test_gen) 5dc562c541e102 Josef Bacik 2012-08-17 4432 continue; 8c6c592831a09a Josef Bacik 2017-08-29 4433 31d11b83b96faa Filipe Manana 2018-05-09 4434 /* We log prealloc extents beyond eof later. */ 31d11b83b96faa Filipe Manana 2018-05-09 4435 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && 31d11b83b96faa Filipe Manana 2018-05-09 4436 em->start >= i_size_read(&inode->vfs_inode)) 31d11b83b96faa Filipe Manana 2018-05-09 4437 continue; 31d11b83b96faa Filipe Manana 2018-05-09 4438 ff44c6e36dc9dc Josef Bacik 2012-09-14 4439 /* Need a ref to keep it from getting evicted from cache */ 490b54d6fb75f6 Elena Reshetova 2017-03-03 4440 refcount_inc(&em->refs); ff44c6e36dc9dc Josef Bacik 2012-09-14 4441 set_bit(EXTENT_FLAG_LOGGING, &em->flags); 5dc562c541e102 Josef Bacik 2012-08-17 4442 list_add_tail(&em->list, &extents); 2ab28f322f9896 Josef Bacik 2012-10-12 4443 num++; 5dc562c541e102 Josef Bacik 2012-08-17 4444 } 5dc562c541e102 Josef Bacik 2012-08-17 4445 5dc562c541e102 Josef Bacik 2012-08-17 4446 list_sort(NULL, &extents, extent_cmp); 2ab28f322f9896 Josef Bacik 2012-10-12 4447 process: 5dc562c541e102 Josef Bacik 2012-08-17 4448 while (!list_empty(&extents)) { 5dc562c541e102 Josef Bacik 2012-08-17 4449 em = list_entry(extents.next, struct extent_map, list); 5dc562c541e102 Josef Bacik 2012-08-17 4450 5dc562c541e102 Josef Bacik 2012-08-17 4451 list_del_init(&em->list); 5dc562c541e102 Josef Bacik 2012-08-17 4452 5dc562c541e102 Josef Bacik 2012-08-17 4453 /* 5dc562c541e102 Josef Bacik 2012-08-17 4454 * If we had an error we just need to delete everybody from our 5dc562c541e102 Josef Bacik 2012-08-17 4455 * private list. 5dc562c541e102 Josef Bacik 2012-08-17 4456 */ ff44c6e36dc9dc Josef Bacik 2012-09-14 4457 if (ret) { 201a90389424d6 Josef Bacik 2013-01-24 4458 clear_em_logging(tree, em); ff44c6e36dc9dc Josef Bacik 2012-09-14 4459 free_extent_map(em); 5dc562c541e102 Josef Bacik 2012-08-17 4460 continue; ff44c6e36dc9dc Josef Bacik 2012-09-14 4461 } ff44c6e36dc9dc Josef Bacik 2012-09-14 4462 ff44c6e36dc9dc Josef Bacik 2012-09-14 4463 write_unlock(&tree->lock); 5dc562c541e102 Josef Bacik 2012-08-17 4464 a2120a473a8090 Josef Bacik 2018-05-23 4465 ret = log_one_extent(trans, inode, root, em, path, ctx); ff44c6e36dc9dc Josef Bacik 2012-09-14 4466 write_lock(&tree->lock); 201a90389424d6 Josef Bacik 2013-01-24 4467 clear_em_logging(tree, em); 201a90389424d6 Josef Bacik 2013-01-24 4468 free_extent_map(em); 5dc562c541e102 Josef Bacik 2012-08-17 4469 } ff44c6e36dc9dc Josef Bacik 2012-09-14 4470 WARN_ON(!list_empty(&extents)); ff44c6e36dc9dc Josef Bacik 2012-09-14 4471 write_unlock(&tree->lock); 5dc562c541e102 Josef Bacik 2012-08-17 4472 5dc562c541e102 Josef Bacik 2012-08-17 4473 btrfs_release_path(path); 31d11b83b96faa Filipe Manana 2018-05-09 4474 if (!ret) 31d11b83b96faa Filipe Manana 2018-05-09 4475 ret = btrfs_log_prealloc_extents(trans, inode, path); 6105869e2ac5f5 Filipe Manana 2020-08-11 4476 if (ret) 6105869e2ac5f5 Filipe Manana 2020-08-11 4477 return ret; 6105869e2ac5f5 Filipe Manana 2020-08-11 4478 6105869e2ac5f5 Filipe Manana 2020-08-11 4479 /* 6105869e2ac5f5 Filipe Manana 2020-08-11 4480 * We have logged all extents successfully, now make sure the commit of 6105869e2ac5f5 Filipe Manana 2020-08-11 4481 * the current transaction waits for the ordered extents to complete 6105869e2ac5f5 Filipe Manana 2020-08-11 4482 * before it commits and wipes out the log trees, otherwise we would 6105869e2ac5f5 Filipe Manana 2020-08-11 4483 * lose data if an ordered extents completes after the transaction 6105869e2ac5f5 Filipe Manana 2020-08-11 4484 * commits and a power failure happens after the transaction commit. 6105869e2ac5f5 Filipe Manana 2020-08-11 4485 */ 6105869e2ac5f5 Filipe Manana 2020-08-11 4486 list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) { 6105869e2ac5f5 Filipe Manana 2020-08-11 4487 list_del_init(&ordered->log_list); 6105869e2ac5f5 Filipe Manana 2020-08-11 4488 set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags); 6105869e2ac5f5 Filipe Manana 2020-08-11 4489 6105869e2ac5f5 Filipe Manana 2020-08-11 4490 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) { 6105869e2ac5f5 Filipe Manana 2020-08-11 4491 spin_lock_irq(&inode->ordered_tree.lock); 6105869e2ac5f5 Filipe Manana 2020-08-11 4492 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) { 6105869e2ac5f5 Filipe Manana 2020-08-11 4493 set_bit(BTRFS_ORDERED_PENDING, &ordered->flags); 6105869e2ac5f5 Filipe Manana 2020-08-11 4494 atomic_inc(&trans->transaction->pending_ordered); 6105869e2ac5f5 Filipe Manana 2020-08-11 4495 } 6105869e2ac5f5 Filipe Manana 2020-08-11 4496 spin_unlock_irq(&inode->ordered_tree.lock); 6105869e2ac5f5 Filipe Manana 2020-08-11 4497 } 6105869e2ac5f5 Filipe Manana 2020-08-11 4498 btrfs_put_ordered_extent(ordered); 6105869e2ac5f5 Filipe Manana 2020-08-11 4499 } 31d11b83b96faa Filipe Manana 2018-05-09 4500 5dc562c541e102 Josef Bacik 2012-08-17 @4501 return ret; 5dc562c541e102 Josef Bacik 2012-08-17 4502 } 5dc562c541e102 Josef Bacik 2012-08-17 4503 :::::: The code at line 4501 was first introduced by commit :::::: 5dc562c541e1026df9d43913c2f6b91156e22d32 Btrfs: turbo charge fsync :::::: TO: Josef Bacik <jbacik(a)fusionio.com&gt; :::::: CC: Chris Mason <chris.mason(a)fusionio.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org