==================================================================
BUG: KCSAN: data-race in blkdev_llseek / set_capacity_and_notify

write to 0xffff8881004314e8 of 8 bytes by task 3933 on cpu 1:
 i_size_write include/linux/fs.h:914 [inline]
 set_capacity block/genhd.c:62 [inline]
 set_capacity_and_notify+0x9d/0x1d0 block/genhd.c:77
 loop_set_size drivers/block/loop.c:231 [inline]
 loop_configure+0xd53/0xf50 drivers/block/loop.c:1054
 lo_ioctl+0x633/0x1280
 blkdev_ioctl+0x20e/0x440 block/ioctl.c:588
 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+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881004314e8 of 8 bytes by task 11787 on cpu 0:
 i_size_read include/linux/fs.h:892 [inline]
 blkdev_llseek+0x4c/0x80 block/fops.c:454
 vfs_llseek fs/read_write.c:300 [inline]
 ksys_lseek fs/read_write.c:313 [inline]
 __do_sys_lseek fs/read_write.c:324 [inline]
 __se_sys_lseek fs/read_write.c:322 [inline]
 __x64_sys_lseek+0xf0/0x150 fs/read_write.c:322
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000000 -> 0x0000000008100000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11787 Comm: udevd Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Buffer I/O error on dev loop3, logical block 0, async page read
Buffer I/O error on dev loop3, logical block 2, async page read
blk_print_req_error: 37 callbacks suppressed
I/O error, dev loop3, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
Buffer I/O error on dev loop3, logical block 3, async page read
I/O error, dev loop3, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop1, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop1, sector 264064 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
Buffer I/O error on dev loop1, logical block 33008, async page read
I/O error, dev loop1, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop1, sector 264064 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
Buffer I/O error on dev loop1, logical block 33008, async page read
Buffer I/O error on dev loop1, logical block 33008, async page read
blk_print_req_error: 42 callbacks suppressed
I/O error, dev loop3, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop3, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop3, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop3, sector 264064 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0