diff options
| author | Ahmed S. Darwish <[email protected]> | 2020-06-03 16:49:48 +0200 |
|---|---|---|
| committer | Jens Axboe <[email protected]> | 2020-06-04 21:22:28 -0600 |
| commit | 15b81ce5abdc4b502aa31dff2d415b79d2349d2f (patch) | |
| tree | 33b5c887643b18efec05f05d65749d0e79af59ac /drivers/fpga/fpga-mgr.c | |
| parent | d24de76af836260a99ca2ba281a937bd5bc55591 (diff) | |
block: nr_sects_write(): Disable preemption on seqcount write
For optimized block readers not holding a mutex, the "number of sectors"
64-bit value is protected from tearing on 32-bit architectures by a
sequence counter.
Disable preemption before entering that sequence counter's write side
critical section. Otherwise, the read side can preempt the write side
section and spin for the entire scheduler tick. If the reader belongs to
a real-time scheduling class, it can spin forever and the kernel will
livelock.
Fixes: c83f6bf98dc1 ("block: add partition resize function to blkpg ioctl")
Cc: <[email protected]>
Signed-off-by: Ahmed S. Darwish <[email protected]>
Reviewed-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Diffstat (limited to 'drivers/fpga/fpga-mgr.c')
0 files changed, 0 insertions, 0 deletions