KCSAN: data-race in delete_from_page_cache_batch / page_mapping (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 13311e74 Linux 5.13-rc7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1289f400300000
kernel config: https://syzkaller.appspot.com/x/.config?x=a702dbad4961cdfa
dashboard link: https://syzkaller.appspot.com/bug?extid=69278bb91f6152a3c417
compiler: Debian clang version 11.0.1-2
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+69278b...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in delete_from_page_cache_batch / page_mapping

write to 0xffffea00041bc798 of 8 bytes by task 30378 on cpu 0:
page_cache_delete_batch mm/filemap.c:318 [inline]
delete_from_page_cache_batch+0x2fc/0x690 mm/filemap.c:349
truncate_inode_pages_range+0x1a5/0xa70 mm/truncate.c:326
truncate_inode_pages+0x20/0x30 mm/truncate.c:424
kill_bdev fs/block_dev.c:86 [inline]
set_blocksize+0x24e/0x270 fs/block_dev.c:166
sb_set_blocksize+0x2c/0xa0 fs/block_dev.c:175
ext4_fill_super+0x227e/0x8030 fs/ext4/super.c:4472
mount_bdev+0x1e8/0x290 fs/super.c:1368
ext4_mount+0x2d/0x40 fs/ext4/super.c:6639
legacy_get_tree+0x70/0xc0 fs/fs_context.c:592
vfs_get_tree+0x4a/0x1a0 fs/super.c:1498
do_new_mount fs/namespace.c:2905 [inline]
path_mount+0x11d4/0x1ce0 fs/namespace.c:3235
do_mount fs/namespace.c:3248 [inline]
__do_sys_mount fs/namespace.c:3456 [inline]
__se_sys_mount+0x23d/0x2e0 fs/namespace.c:3433
__x64_sys_mount+0x63/0x70 fs/namespace.c:3433
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffffea00041bc798 of 8 bytes by task 30284 on cpu 1:
page_mapping+0x111/0x1c0 mm/util.c:706
page_evictable mm/internal.h:83 [inline]
__pagevec_lru_add_fn+0x82/0x490 mm/swap.c:1033
__pagevec_lru_add+0x1c0/0x2b0 mm/swap.c:1061
lru_cache_add+0x121/0x150 mm/swap.c:475
add_to_page_cache_lru+0x150/0x1b0 mm/filemap.c:983
page_cache_ra_unbounded+0x262/0x410 mm/readahead.c:221
do_page_cache_ra mm/readahead.c:267 [inline]
force_page_cache_ra+0x246/0x280 mm/readahead.c:299
page_cache_sync_ra+0xcc/0xe0 mm/readahead.c:573
page_cache_sync_readahead include/linux/pagemap.h:879 [inline]
filemap_get_pages mm/filemap.c:2467 [inline]
filemap_read+0x388/0x1230 mm/filemap.c:2550
generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2701
blkdev_read_iter+0xb9/0xf0 fs/block_dev.c:1730
call_read_iter include/linux/fs.h:2108 [inline]
new_sync_read fs/read_write.c:415 [inline]
vfs_read+0x565/0x5d0 fs/read_write.c:496
ksys_read+0xce/0x180 fs/read_write.c:634
__do_sys_read fs/read_write.c:644 [inline]
__se_sys_read fs/read_write.c:642 [inline]
__x64_sys_read+0x3e/0x50 fs/read_write.c:642
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffff888101391598 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 30284 Comm: systemd-udevd Not tainted 5.13.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.