syzbot

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BUG: KCSAN: data-race in delete_from_page_cache_batch / page_mapping

write to 0xffffea00053fdf18 of 8 bytes by task 25770 on cpu 1:
 page_cache_delete_batch mm/filemap.c:327 [inline]
 delete_from_page_cache_batch+0x37b/0x810 mm/filemap.c:358
 truncate_inode_pages_range+0x482/0x10c0 mm/truncate.c:366
 truncate_inode_pages+0x20/0x30 mm/truncate.c:476
 kill_bdev fs/block_dev.c:86 [inline]
 set_blocksize+0x286/0x2a0 fs/block_dev.c:150
 sb_set_blocksize+0x2c/0xa0 fs/block_dev.c:159
 isofs_fill_super+0x1043/0x18b0 fs/isofs/inode.c:860
 mount_bdev+0x1e2/0x280 fs/super.c:1366
 isofs_mount+0x2d/0x40 fs/isofs/inode.c:1565
 legacy_get_tree+0x70/0xc0 fs/fs_context.c:592
 vfs_get_tree+0x4a/0x190 fs/super.c:1496
 do_new_mount fs/namespace.c:2878 [inline]
 path_mount+0x119d/0x1c10 fs/namespace.c:3208
 do_mount fs/namespace.c:3221 [inline]
 __do_sys_mount fs/namespace.c:3429 [inline]
 __se_sys_mount+0x23d/0x2e0 fs/namespace.c:3406
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3406
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffea00053fdf18 of 8 bytes by task 25773 on cpu 0:
 page_mapping+0x13b/0x200 mm/util.c:706
 page_evictable mm/internal.h:84 [inline]
 __pagevec_lru_add_fn+0xb1/0x550 mm/swap.c:996
 __pagevec_lru_add+0x19a/0x280 mm/swap.c:1026
 lru_cache_add+0x102/0x160 mm/swap.c:465
 shmem_getpage_gfp+0x8b3/0x1960 mm/shmem.c:1932
 shmem_getpage mm/shmem.c:155 [inline]
 shmem_file_read_iter+0x1b5/0x760 mm/shmem.c:2605
 call_read_iter include/linux/fs.h:1895 [inline]
 do_iter_readv_writev+0x2e8/0x360 fs/read_write.c:738
 do_iter_read+0x109/0x4b0 fs/read_write.c:801
 vfs_iter_read+0x4c/0x70 fs/read_write.c:843
 lo_read_simple drivers/block/loop.c:360 [inline]
 do_req_filebacked drivers/block/loop.c:636 [inline]
 loop_handle_cmd drivers/block/loop.c:2037 [inline]
 loop_queue_work+0xdfb/0x1320 drivers/block/loop.c:2055
 kthread_worker_fn+0x28f/0x530 kernel/kthread.c:710
 loop_kthread_worker_fn+0x31/0x40 drivers/block/loop.c:932
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 25773 Comm: loop4 Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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