syzbot

loop1: detected capacity change from 0 to 512
EXT4-fs (loop1): external journal device major/minor numbers have changed
EXT4-fs (loop1): couldn't read superblock of external journal
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BUG: KCSAN: data-race in __filemap_add_folio / invalidate_bdev

read-write to 0xffff8881004c11f0 of 8 bytes by task 3291 on cpu 0:
 __filemap_add_folio+0x430/0x6f0 mm/filemap.c:929
 filemap_add_folio+0x9c/0x1b0 mm/filemap.c:981
 page_cache_ra_unbounded+0x1c1/0x350 mm/readahead.c:276
 do_page_cache_ra mm/readahead.c:328 [inline]
 force_page_cache_ra mm/readahead.c:357 [inline]
 page_cache_sync_ra+0x252/0x680 mm/readahead.c:585
 filemap_get_pages+0x2ca/0x11a0 mm/filemap.c:2580
 filemap_read+0x230/0x8c0 mm/filemap.c:2691
 blkdev_read_iter+0x228/0x2d0 block/fops.c:796
 new_sync_read fs/read_write.c:484 [inline]
 vfs_read+0x5cc/0x6f0 fs/read_write.c:565
 ksys_read+0xe8/0x1b0 fs/read_write.c:708
 __do_sys_read fs/read_write.c:717 [inline]
 __se_sys_read fs/read_write.c:715 [inline]
 __x64_sys_read+0x42/0x50 fs/read_write.c:715
 x64_sys_call+0x2874/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881004c11f0 of 8 bytes by task 3905 on cpu 1:
 invalidate_bdev+0x25/0x70 block/bdev.c:99
 __ext4_fill_super fs/ext4/super.c:5697 [inline]
 ext4_fill_super+0x14e1/0x3630 fs/ext4/super.c:5722
 get_tree_bdev_flags+0x29f/0x310 fs/super.c:1636
 get_tree_bdev+0x1f/0x30 fs/super.c:1659
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5754
 vfs_get_tree+0x56/0x1e0 fs/super.c:1814
 do_new_mount+0x227/0x690 fs/namespace.c:3560
 path_mount+0x49b/0xb30 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:4088
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4088
 x64_sys_call+0x2c84/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000007 -> 0x0000000000000008

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3905 Comm: syz.1.160 Not tainted 6.14.0-rc6-syzkaller-00145-g695caca9345a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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