[ammarfaizi2-block:dhowells/linux-fs/netfs-linked-list 58/59] fs/netfs/buffered_flush.c:664 netfs_find_writeback_start() error: uninitialized symbol 'ret'.
From: Dan Carpenter
Date: Mon Jun 06 2022 - 08:25:20 EST
tree: https://github.com/ammarfaizi2/linux-block dhowells/linux-fs/netfs-linked-list
head: 22ecc2fcdab4616e624408911ec1d54644e82030
commit: ff509dc49891f934a7a774e277b87729018db753 [58/59] netfs: Use flush from afs_writeback
config: x86_64-randconfig-m001 (https://download.01.org/0day-ci/archive/20220603/202206031529.CM5I3dvU-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.3.0-1) 11.3.0
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
smatch warnings:
fs/netfs/buffered_flush.c:664 netfs_find_writeback_start() error: uninitialized symbol 'ret'.
vim +/ret +664 fs/netfs/buffered_flush.c
ff509dc49891f93 David Howells 2022-04-28 553 static int netfs_find_writeback_start(struct netfs_io_request *wreq,
ff509dc49891f93 David Howells 2022-04-28 554 struct writeback_control *wbc,
ff509dc49891f93 David Howells 2022-04-28 555 struct netfs_dirty_region *region,
ff509dc49891f93 David Howells 2022-04-28 556 pgoff_t *_first, pgoff_t last)
ff509dc49891f93 David Howells 2022-04-28 557 {
ff509dc49891f93 David Howells 2022-04-28 558 struct folio *folio;
ff509dc49891f93 David Howells 2022-04-28 559 ssize_t ret;
ff509dc49891f93 David Howells 2022-04-28 560 bool dirty;
ff509dc49891f93 David Howells 2022-04-28 561 int skips = 0;
c403641768e0a37 David Howells 2021-06-29 562
ff509dc49891f93 David Howells 2022-04-28 563 _enter("%lx,%lx,", *_first, last);
c403641768e0a37 David Howells 2021-06-29 564
ff509dc49891f93 David Howells 2022-04-28 565 retry:
ff509dc49891f93 David Howells 2022-04-28 566 folio = __filemap_get_folio(wreq->mapping, *_first, 0, 0);
ff509dc49891f93 David Howells 2022-04-28 567 if (!folio) {
ff509dc49891f93 David Howells 2022-04-28 568 pr_warn("Folio %lx in dirty region D=%x not present\n",
ff509dc49891f93 David Howells 2022-04-28 569 *_first, region->debug_id);
ff509dc49891f93 David Howells 2022-04-28 570 return 0;
c403641768e0a37 David Howells 2021-06-29 571 }
c403641768e0a37 David Howells 2021-06-29 572
ff509dc49891f93 David Howells 2022-04-28 573 /* At this point we hold neither the i_pages lock nor the folio lock:
ff509dc49891f93 David Howells 2022-04-28 574 * the folio may be truncated or invalidated (changing folio->mapping to
ff509dc49891f93 David Howells 2022-04-28 575 * NULL), or even swizzled back from swapper_space to tmpfs file
ff509dc49891f93 David Howells 2022-04-28 576 * mapping
ff509dc49891f93 David Howells 2022-04-28 577 */
ff509dc49891f93 David Howells 2022-04-28 578 if (wbc->sync_mode != WB_SYNC_NONE) {
ff509dc49891f93 David Howells 2022-04-28 579 ret = folio_lock_killable(folio);
ff509dc49891f93 David Howells 2022-04-28 580 if (ret < 0) {
ff509dc49891f93 David Howells 2022-04-28 581 folio_put(folio);
ff509dc49891f93 David Howells 2022-04-28 582 _leave(" = %zd [lock]", ret);
ff509dc49891f93 David Howells 2022-04-28 583 return ret;
ff509dc49891f93 David Howells 2022-04-28 584 }
ff509dc49891f93 David Howells 2022-04-28 585 } else {
ff509dc49891f93 David Howells 2022-04-28 586 if (!folio_trylock(folio)) {
ff509dc49891f93 David Howells 2022-04-28 587 folio_put(folio);
ff509dc49891f93 David Howells 2022-04-28 588 _leave(" = 0 [trylock]");
ff509dc49891f93 David Howells 2022-04-28 589 return 0;
ff509dc49891f93 David Howells 2022-04-28 590 }
ff509dc49891f93 David Howells 2022-04-28 591 }
c403641768e0a37 David Howells 2021-06-29 592
ff509dc49891f93 David Howells 2022-04-28 593 /* A dirty region must fit exactly over a span of folios - there should
ff509dc49891f93 David Howells 2022-04-28 594 * be no partial folio coverage.
ff509dc49891f93 David Howells 2022-04-28 595 */
ff509dc49891f93 David Howells 2022-04-28 596 if (*_first < folio->index) {
ff509dc49891f93 David Howells 2022-04-28 597 pr_warn("Folio %lx extends before dirty region D=%x\n",
ff509dc49891f93 David Howells 2022-04-28 598 *_first, region->debug_id);
ff509dc49891f93 David Howells 2022-04-28 599 goto skip;
c403641768e0a37 David Howells 2021-06-29 600 }
c403641768e0a37 David Howells 2021-06-29 601
ff509dc49891f93 David Howells 2022-04-28 602 if (folio_mapping(folio) != wreq->mapping) {
ff509dc49891f93 David Howells 2022-04-28 603 pr_warn("Folio %lx in dirty region D=%x has no mapping set\n",
ff509dc49891f93 David Howells 2022-04-28 604 *_first, region->debug_id);
ff509dc49891f93 David Howells 2022-04-28 605 goto skip;
ff509dc49891f93 David Howells 2022-04-28 606 }
c403641768e0a37 David Howells 2021-06-29 607
ff509dc49891f93 David Howells 2022-04-28 608 /* Any folio we have to include must not already have writeback in
ff509dc49891f93 David Howells 2022-04-28 609 * progress otherwise we may get a race against old data being written.
c403641768e0a37 David Howells 2021-06-29 610 */
ff509dc49891f93 David Howells 2022-04-28 611 if (folio_test_writeback(folio)) {
ff509dc49891f93 David Howells 2022-04-28 612 folio_unlock(folio);
ff509dc49891f93 David Howells 2022-04-28 613 if (wbc->sync_mode != WB_SYNC_NONE)
ff509dc49891f93 David Howells 2022-04-28 614 folio_wait_writeback(folio);
ff509dc49891f93 David Howells 2022-04-28 615 else
ff509dc49891f93 David Howells 2022-04-28 616 *_first = folio_next_index(folio);
ff509dc49891f93 David Howells 2022-04-28 617 folio_put(folio);
ff509dc49891f93 David Howells 2022-04-28 618 if (wbc->sync_mode == WB_SYNC_NONE) {
ff509dc49891f93 David Howells 2022-04-28 619 if (skips >= 5 || need_resched())
ff509dc49891f93 David Howells 2022-04-28 620 return 0;
ff509dc49891f93 David Howells 2022-04-28 621 skips++;
ff509dc49891f93 David Howells 2022-04-28 622 }
ff509dc49891f93 David Howells 2022-04-28 623 goto retry;
ff509dc49891f93 David Howells 2022-04-28 624 }
ff509dc49891f93 David Howells 2022-04-28 625
ff509dc49891f93 David Howells 2022-04-28 626 /* A dirty region may include a number of folios that are clean in order
ff509dc49891f93 David Howells 2022-04-28 627 * to make up a minimum-sized unit for writing, e.g. if we need to
ff509dc49891f93 David Howells 2022-04-28 628 * compress a large block or write a bigger unit to the cache, so we
ff509dc49891f93 David Howells 2022-04-28 629 * need to keep track of that in case the write op fails.
ff509dc49891f93 David Howells 2022-04-28 630 */
ff509dc49891f93 David Howells 2022-04-28 631 dirty = folio_clear_dirty_for_io(folio);
ff509dc49891f93 David Howells 2022-04-28 632 trace_netfs_folio_dirty(wreq->mapping, folio, netfs_folio_trace_store);
ff509dc49891f93 David Howells 2022-04-28 633 trace_netfs_wb_page(wreq, folio);
ff509dc49891f93 David Howells 2022-04-28 634 if (folio_start_writeback(folio)) {
ff509dc49891f93 David Howells 2022-04-28 635 kdebug ("start wb failed");
ff509dc49891f93 David Howells 2022-04-28 636 goto out_unlock;
"ret" uninitialized on this path.
ff509dc49891f93 David Howells 2022-04-28 637 }
ff509dc49891f93 David Howells 2022-04-28 638
ff509dc49891f93 David Howells 2022-04-28 639 ret = netfs_xa_store_and_mark(&wreq->buffer, folio->index, folio,
ff509dc49891f93 David Howells 2022-04-28 640 true, true, dirty, GFP_NOFS);
ff509dc49891f93 David Howells 2022-04-28 641 if (ret < 0) {
ff509dc49891f93 David Howells 2022-04-28 642 kdebug("oom store");
ff509dc49891f93 David Howells 2022-04-28 643 goto nomem;
ff509dc49891f93 David Howells 2022-04-28 644 }
ff509dc49891f93 David Howells 2022-04-28 645
ff509dc49891f93 David Howells 2022-04-28 646 wreq->first = folio->index;
ff509dc49891f93 David Howells 2022-04-28 647 wreq->last = folio_next_index(folio) - 1;
ff509dc49891f93 David Howells 2022-04-28 648 wreq->len = folio_size(folio);
ff509dc49891f93 David Howells 2022-04-28 649 wreq->start = folio_pos(folio);
ff509dc49891f93 David Howells 2022-04-28 650 if (wreq->start >= wreq->i_size) {
ff509dc49891f93 David Howells 2022-04-28 651 pr_err("wreq->start >= wreq->i_size\n");
ff509dc49891f93 David Howells 2022-04-28 652 wreq->len = 0;
ff509dc49891f93 David Howells 2022-04-28 653 ret = -EIO;
ff509dc49891f93 David Howells 2022-04-28 654 goto out_unlock;
ff509dc49891f93 David Howells 2022-04-28 655 }
ff509dc49891f93 David Howells 2022-04-28 656 _debug("START %zx @%llx [%llx]", wreq->len, wreq->start, wreq->i_size);
ff509dc49891f93 David Howells 2022-04-28 657 if (wreq->len > wreq->i_size - wreq->start)
ff509dc49891f93 David Howells 2022-04-28 658 wreq->len = wreq->i_size - wreq->start;
ff509dc49891f93 David Howells 2022-04-28 659 *_first = wreq->last + 1;
ff509dc49891f93 David Howells 2022-04-28 660 ret = 1;
ff509dc49891f93 David Howells 2022-04-28 661 out_unlock:
ff509dc49891f93 David Howells 2022-04-28 662 folio_unlock(folio);
ff509dc49891f93 David Howells 2022-04-28 663 _leave(" = %zd [%lx]", ret, *_first);
ff509dc49891f93 David Howells 2022-04-28 @664 return ret;
ff509dc49891f93 David Howells 2022-04-28 665
ff509dc49891f93 David Howells 2022-04-28 666 nomem:
ff509dc49891f93 David Howells 2022-04-28 667 if (dirty)
ff509dc49891f93 David Howells 2022-04-28 668 folio_redirty_for_writepage(wbc, folio);
ff509dc49891f93 David Howells 2022-04-28 669 folio_end_writeback(folio);
ff509dc49891f93 David Howells 2022-04-28 670 goto out_unlock;
ff509dc49891f93 David Howells 2022-04-28 671
ff509dc49891f93 David Howells 2022-04-28 672 skip:
ff509dc49891f93 David Howells 2022-04-28 673 BUG();
ff509dc49891f93 David Howells 2022-04-28 674 }
--
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