diff options
| author | Amy Chiang <amychiang@qnap.com> | 2018-05-16 13:59:35 +0300 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2018-05-17 19:56:00 +0300 |
| commit | 448ec638c6bcf36923db695b6188373b933e7ddc (patch) | |
| tree | 93f2a31884891c877ea6fd7e4d4cdcd70119490a /drivers/md | |
| parent | b33d10624fdc15cdf1495f3f00481afccec76783 (diff) | |
| download | linux-448ec638c6bcf36923db695b6188373b933e7ddc.tar.xz | |
md/raid5: Assigning NULL to sh->batch_head before testing bit R5_Overlap of a stripe
In add_stripe_bio(), if the stripe_head is in batch list, the incoming
bio is regarded as overlapping, and the bit R5_Overlap on this stripe_head
is set. break_stripe_batch_list() checks bit R5_Overlap on each stripe_head
first then assigns NULL to sh->batch_head.
If break_stripe_batch_list() checks bit R5_Overlap on stripe_head A
after add_stripe_bio() finds stripe_head A is in batch list and before
add_stripe_bio() sets bit R5_Overlapt of stripe_head A,
break_stripe_batch_list() would not know there's a process in
wait_for_overlap and needs to call wake_up(). There's a huge chance a
process never returns from schedule() if add_stripe_bio() is called
from raid5_make_request().
In break_stripe_batch_list(), assigning NULL to sh->batch_head should
be done before it checks bit R5_Overlap of a stripe_head.
Signed-off-by: Amy Chiang <amychiang@qnap.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 1e1515c817ff..d034a20a12be 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4620,15 +4620,15 @@ static void break_stripe_batch_list(struct stripe_head *head_sh, sh->check_state = head_sh->check_state; sh->reconstruct_state = head_sh->reconstruct_state; + spin_lock_irq(&sh->stripe_lock); + sh->batch_head = NULL; + spin_unlock_irq(&sh->stripe_lock); for (i = 0; i < sh->disks; i++) { if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags)) do_wakeup = 1; sh->dev[i].flags = head_sh->dev[i].flags & (~((1 << R5_WriteError) | (1 << R5_Overlap))); } - spin_lock_irq(&sh->stripe_lock); - sh->batch_head = NULL; - spin_unlock_irq(&sh->stripe_lock); if (handle_flags == 0 || sh->state & handle_flags) set_bit(STRIPE_HANDLE, &sh->state); |