[goldwynr:iomap 27/33] fs/btrfs/file.c:1517:19-21: ERROR: reference preceded by free on line 1516 (fwd)

From: Julia Lawall
Date: Thu Dec 30 2021 - 07:54:56 EST



---------- Forwarded message ----------
Date: Thu, 30 Dec 2021 19:59:25 +0800
From: kernel test robot <lkp@xxxxxxxxx>
To: kbuild@xxxxxxxxxxxx
Cc: lkp@xxxxxxxxx, Julia Lawall <julia.lawall@xxxxxxx>
Subject: [goldwynr:iomap 27/33] fs/btrfs/file.c:1517:19-21: ERROR: reference
preceded by free on line 1516

CC: kbuild-all@xxxxxxxxxxxx
CC: linux-kernel@xxxxxxxxxxxxxxx
TO: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>

tree: https://github.com/goldwynr/linux iomap
head: 30c74a8c201365178cae26d0d7aefa120c3245ab
commit: f3623890897fee87c24f37ae01a2f1a5c35a39d9 [27/33] btrfs: use srcmap for read-before-write cases
:::::: branch date: 13 hours ago
:::::: commit date: 18 hours ago
config: i386-randconfig-c001-20211228 (https://download.01.org/0day-ci/archive/20211230/202112301901.eLLE2zEp-lkp@xxxxxxxxx/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 <lkp@xxxxxxxxx>
Reported-by: Julia Lawall <julia.lawall@xxxxxxx>


cocci warnings: (new ones prefixed by >>)
>> fs/btrfs/file.c:1517:19-21: ERROR: reference preceded by free on line 1516

vim +1517 fs/btrfs/file.c

e95dc238df949a Goldwyn Rodrigues 2021-05-11 1489
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1490 static int btrfs_buffered_iomap_begin(struct inode *inode, loff_t pos,
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1491 loff_t length, unsigned flags, struct iomap *iomap,
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1492 struct iomap *srcmap)
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1493 {
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1494 int ret;
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1495 size_t write_bytes = length;
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1496 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1497 size_t sector_offset = pos & (fs_info->sectorsize - 1);
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1498 struct btrfs_iomap *bi;
f3623890897fee Goldwyn Rodrigues 2021-04-21 1499 loff_t end = pos + length;
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1500
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1501 bi = kzalloc(sizeof(struct btrfs_iomap), GFP_NOFS);
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1502 if (!bi)
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1503 return -ENOMEM;
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1504
f3623890897fee Goldwyn Rodrigues 2021-04-21 1505 if ((pos & (PAGE_SIZE - 1) || end & (PAGE_SIZE - 1))) {
f3623890897fee Goldwyn Rodrigues 2021-04-21 1506 loff_t isize = i_size_read(inode);
f3623890897fee Goldwyn Rodrigues 2021-04-21 1507 if (pos >= isize) {
f3623890897fee Goldwyn Rodrigues 2021-04-21 1508 srcmap->addr = IOMAP_NULL_ADDR;
f3623890897fee Goldwyn Rodrigues 2021-04-21 1509 srcmap->type = IOMAP_HOLE;
f3623890897fee Goldwyn Rodrigues 2021-04-21 1510 srcmap->offset = isize;
f3623890897fee Goldwyn Rodrigues 2021-04-21 1511 srcmap->length = end - isize;
f3623890897fee Goldwyn Rodrigues 2021-04-21 1512 } else {
f3623890897fee Goldwyn Rodrigues 2021-04-21 1513 bi->em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
f3623890897fee Goldwyn Rodrigues 2021-04-21 1514 pos - sector_offset, length);
f3623890897fee Goldwyn Rodrigues 2021-04-21 1515 if (IS_ERR(bi->em)) {
f3623890897fee Goldwyn Rodrigues 2021-04-21 @1516 kfree(bi);
f3623890897fee Goldwyn Rodrigues 2021-04-21 @1517 return PTR_ERR(bi->em);
f3623890897fee Goldwyn Rodrigues 2021-04-21 1518 }
f3623890897fee Goldwyn Rodrigues 2021-04-21 1519 btrfs_em_to_iomap(inode, bi->em, srcmap,
f3623890897fee Goldwyn Rodrigues 2021-04-21 1520 pos - sector_offset);
f3623890897fee Goldwyn Rodrigues 2021-04-21 1521 }
f3623890897fee Goldwyn Rodrigues 2021-04-21 1522 }
f3623890897fee Goldwyn Rodrigues 2021-04-21 1523
f3623890897fee Goldwyn Rodrigues 2021-04-21 1524 if ((srcmap->type != IOMAP_HOLE) &&
f3623890897fee Goldwyn Rodrigues 2021-04-21 1525 (end > srcmap->offset + srcmap->length))
f3623890897fee Goldwyn Rodrigues 2021-04-21 1526 write_bytes = srcmap->offset + srcmap->length - pos;
f3623890897fee Goldwyn Rodrigues 2021-04-21 1527
f3623890897fee Goldwyn Rodrigues 2021-04-21 1528
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1529 ret = btrfs_check_data_free_space(BTRFS_I(inode),
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1530 &bi->data_reserved, pos, write_bytes);
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1531 if (ret < 0) {
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1532 /*
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1533 * If we don't have to COW at the offset, reserve
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1534 * metadata only. write_bytes may get smaller than
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1535 * requested here.
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1536 */
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1537 if (btrfs_check_nocow_lock(BTRFS_I(inode), pos,
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1538 &write_bytes) > 0)
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1539 bi->metadata_only = true;
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1540 else
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1541 return ret;
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1542 }
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1543
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1544 bi->reserved_bytes = round_up(write_bytes + sector_offset,
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1545 fs_info->sectorsize);
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1546 WARN_ON(bi->reserved_bytes == 0);
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1547 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1548 bi->reserved_bytes);
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1549 if (ret) {
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1550 if (!bi->metadata_only)
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1551 btrfs_free_reserved_data_space(BTRFS_I(inode),
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1552 bi->data_reserved, pos,
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1553 write_bytes);
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1554 else
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1555 btrfs_check_nocow_unlock(BTRFS_I(inode));
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1556 return ret;
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1557 }
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1558
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1559 if (pos < inode->i_size) {
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1560 bi->lockstart = round_down(pos, fs_info->sectorsize);
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1561 bi->lockend = round_up(pos + write_bytes, fs_info->sectorsize) - 1;
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1562 btrfs_lock_and_flush_ordered_range(BTRFS_I(inode),
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1563 bi->lockstart, bi->lockend,
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1564 &bi->cached_state);
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1565 bi->extents_locked = true;
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1566 }
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1567
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1568 iomap->private = bi;
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1569 iomap->length = round_up(write_bytes + sector_offset,
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1570 fs_info->sectorsize);
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1571 iomap->offset = round_down(pos, fs_info->sectorsize);
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1572 iomap->addr = IOMAP_NULL_ADDR;
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1573 iomap->type = IOMAP_DELALLOC;
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1574 iomap->bdev = fs_info->fs_devices->latest_dev->bdev;
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1575 iomap->page_ops = &btrfs_iomap_page_ops;
f4ecee4435f363 Goldwyn Rodrigues 2021-04-21 1576
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1577 return 0;
b192ee8d4db510 Goldwyn Rodrigues 2021-04-21 1578

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