syzbot

loop4: detected capacity change from 0 to 4096
==================================================================
BUG: KCSAN: data-race in __add_to_page_cache_locked / truncate_inode_pages_range

write to 0xffff8881013b0630 of 8 bytes by task 8800 on cpu 1:
 __add_to_page_cache_locked+0x298/0x520 mm/filemap.c:930
 add_to_page_cache_lru+0xa0/0x1b0 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:874 [inline]
 filemap_get_pages mm/filemap.c:2483 [inline]
 filemap_read+0x388/0x1230 mm/filemap.c:2566
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2717
 blkdev_read_iter+0xb3/0xc0 fs/block_dev.c:1720
 call_read_iter include/linux/fs.h:2110 [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

read to 0xffff8881013b0630 of 8 bytes by task 8807 on cpu 0:
 truncate_inode_pages_range+0x40/0xac0 mm/truncate.c:298
 truncate_inode_pages+0x20/0x30 mm/truncate.c:428
 kill_bdev fs/block_dev.c:86 [inline]
 set_blocksize+0x286/0x2a0 fs/block_dev.c:166
 sb_set_blocksize fs/block_dev.c:175 [inline]
 sb_min_blocksize+0x9d/0x120 fs/block_dev.c:191
 ext4_fill_super+0x395/0x8010 fs/ext4/super.c:4072
 mount_bdev+0x1e8/0x290 fs/super.c:1368
 ext4_mount+0x2d/0x40 fs/ext4/super.c:6632
 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

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8807 Comm: syz-executor.4 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
EXT4-fs warning (device loop4): ext4_multi_mount_protect:324: MMP startup interrupted, failing mount