Hello Chao Yu,
The patch df634f444ee9: "f2fs: use rb_*_cached friends" from Oct 4,
2018, leads to the following static checker warning:
fs/f2fs/extent_cache.c:606 f2fs_update_extent_tree_range()
error: uninitialized symbol 'leftmost'.
fs/f2fs/extent_cache.c
497 static void f2fs_update_extent_tree_range(struct inode *inode,
498 pgoff_t fofs, block_t blkaddr, unsigned
int len)
499 {
500 struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
501 struct extent_tree *et = F2FS_I(inode)->extent_tree;
502 struct extent_node *en = NULL, *en1 = NULL;
503 struct extent_node *prev_en = NULL, *next_en = NULL;
504 struct extent_info ei, dei, prev;
505 struct rb_node **insert_p = NULL, *insert_parent = NULL;
506 unsigned int end = fofs + len;
507 unsigned int pos = (unsigned int)fofs;
508 bool updated = false;
509 bool leftmost;
510
511 if (!et)
512 return;
513
514 trace_f2fs_update_extent_tree_range(inode, fofs, blkaddr, len);
515
516 write_lock(&et->lock);
517
518 if (is_inode_flag_set(inode, FI_NO_EXTENT)) {
519 write_unlock(&et->lock);
520 return;
521 }
522
523 prev = et->largest;
524 dei.len = 0;
525
526 /*
527 * drop largest extent before lookup, in case it's already
528 * been shrunk from extent tree
529 */
530 __drop_largest_extent(et, fofs, len);
531
532 /* 1. lookup first extent node in range [fofs, fofs + len - 1]
*/
533 en = (struct extent_node *)f2fs_lookup_rb_tree_ret(&et->root,
534 (struct rb_entry
*)et->cached_en, fofs,
535 (struct rb_entry **)&prev_en,
536 (struct rb_entry **)&next_en,
537 &insert_p, &insert_parent,
false,
538 &leftmost);
^^^^^^^^
Not always initialized in there.
539 if (!en)
540 en = next_en;
541
542 /* 2. invlidate all extent nodes in range [fofs, fofs + len -
1] */
543 while (en && en->ei.fofs < end) {
544 unsigned int org_end;
545 int parts = 0; /* # of parts current extent split into
*/
546
547 next_en = en1 = NULL;
548
549 dei = en->ei;
550 org_end = dei.fofs + dei.len;
551 f2fs_bug_on(sbi, pos >= org_end);
552
553 if (pos > dei.fofs && pos - dei.fofs >=
F2FS_MIN_EXTENT_LEN) {
554 en->ei.len = pos - en->ei.fofs;
555 prev_en = en;
556 parts = 1;
557 }
558
559 if (end < org_end && org_end - end >=
F2FS_MIN_EXTENT_LEN) {
560 if (parts) {
561 set_extent_info(&ei, end,
562 end - dei.fofs +
dei.blk,
563 org_end - end);
564 en1 = __insert_extent_tree(sbi, et, &ei,
565 NULL, NULL,
true);
566 next_en = en1;
567 } else {
568 en->ei.fofs = end;
569 en->ei.blk += end - dei.fofs;
570 en->ei.len -= end - dei.fofs;
571 next_en = en;
572 }
573 parts++;
574 }
575
576 if (!next_en) {
577 struct rb_node *node = rb_next(&en->rb_node);
578
579 next_en = rb_entry_safe(node, struct
extent_node,
580 rb_node);
581 }
582
583 if (parts)
584 __try_update_largest_extent(et, en);
585 else
586 __release_extent_node(sbi, et, en);
587
588 /*
589 * if original extent is split into zero or two parts,
extent
590 * tree has been altered by deletion or insertion,
therefore
591 * invalidate pointers regard to tree.
592 */
593 if (parts != 1) {
594 insert_p = NULL;
595 insert_parent = NULL;
596 }
597 en = next_en;
598 }
599
600 /* 3. update extent in extent cache */
601 if (blkaddr) {
602
603 set_extent_info(&ei, fofs, blkaddr, len);
604 if (!__try_merge_extent_node(sbi, et, &ei, prev_en,
next_en))
605 __insert_extent_tree(sbi, et, &ei,
606 insert_p, insert_parent,
leftmost);
^^^^^^^^
Smatch complains, but I'm to stupid to know if it's valid.
607
608 /* give up extent_cache, if split and small updates
happen */
609 if (dei.len >= 1 &&
610 prev.len < F2FS_MIN_EXTENT_LEN &&
611 et->largest.len < F2FS_MIN_EXTENT_LEN) {
612 et->largest.len = 0;
613 et->largest_updated = true;
614 set_inode_flag(inode, FI_NO_EXTENT);
615 }
616 }
regards,
dan carpenter
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