syzbot

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BUG: KCSAN: data-race in __lru_add_drain_all / lru_cache_add

write to 0xffff888237d22528 of 1 bytes by task 7124 on cpu 1:
 pagevec_add include/linux/pagevec.h:74 [inline]
 pagevec_add_and_need_flush mm/swap.c:222 [inline]
 lru_cache_add+0x75/0x150 mm/swap.c:452
 add_to_page_cache_lru+0x150/0x1b0 mm/filemap.c:1000
 pagecache_get_page+0x6ad/0x910 mm/filemap.c:1951
 grab_cache_page_write_begin+0x3f/0x70 mm/filemap.c:3724
 ext4_da_write_begin+0x323/0x570 fs/ext4/inode.c:2961
 generic_perform_write+0x1b8/0x3e0 mm/filemap.c:3770
 ext4_buffered_write_iter+0x305/0x400 fs/ext4/file.c:269
 ext4_file_write_iter+0x2e7/0x11f0
 call_write_iter include/linux/fs.h:2163 [inline]
 aio_write+0x2b4/0x390 fs/aio.c:1578
 io_submit_one+0x86f/0x13b0 fs/aio.c:1880
 __do_sys_io_submit fs/aio.c:1939 [inline]
 __se_sys_io_submit+0x105/0x270 fs/aio.c:1909
 __x64_sys_io_submit+0x3f/0x50 fs/aio.c:1909
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888237d22528 of 1 bytes by task 7121 on cpu 0:
 pagevec_count include/linux/pagevec.h:61 [inline]
 __lru_add_drain_all+0x12c/0x3e0 mm/swap.c:819
 lru_add_drain_all+0xc/0x10 mm/swap.c:841
 invalidate_bdev+0x56/0x80 block/bdev.c:87
 __loop_clr_fd+0x521/0x850 drivers/block/loop.c:1399
 loop_clr_fd drivers/block/loop.c:1494 [inline]
 lo_ioctl+0xac5/0x13e0 drivers/block/loop.c:1850
 blkdev_ioctl+0x1d0/0x3f0 block/ioctl.c:589
 block_ioctl+0x6e/0x80 block/fops.c:478
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:860
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x02 -> 0x04

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7121 Comm: syz-executor.3 Not tainted 5.15.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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loop3: detected capacity change from 0 to 1054
EXT4-fs (loop3): blocks per group (149504) and clusters per group (8192) inconsistent