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| author | NeilBrown <neilb@suse.com> | 2016-06-02 16:19:52 +1000 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2016-06-13 11:54:13 -0700 |
| commit | 414e6b9a7032a6c2f5ddf018fdb199190b075170 (patch) | |
| tree | c9876ef9b5a3b111ee93d0215bb27190f5cb6505 /drivers/md/raid10.c | |
| parent | 8430e7e0af9a15063b90343e3beebc164c8e90f3 (diff) | |
| download | op-kernel-dev-414e6b9a7032a6c2f5ddf018fdb199190b075170.zip op-kernel-dev-414e6b9a7032a6c2f5ddf018fdb199190b075170.tar.gz | |
md/raid1, raid10: don't recheck "Faulty" flag in read-balance.
Re-checking the faulty flag here brings no value.
The comment about "risk" refers to the risk that the device could
be in the process of being removed by ->hot_remove_disk().
However providing that the ->nr_pending count is incremented inside
an rcu_read_locked() region, there is no risk of that happening.
This is because the rdev pointer (in the personalities array) is set
to NULL before synchronize_rcu(), and ->nr_pending is tested
afterwards. If the rcu_read_locked region happens before the
synchronize_rcu(), the test will see that nr_pending has been incremented.
If it happens afterwards, the rdev pointer will be NULL so there is nothing
to increment.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/raid10.c')
| -rw-r--r-- | drivers/md/raid10.c | 8 |
1 files changed, 0 insertions, 8 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 3578d3a..ae4dce1 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -707,7 +707,6 @@ static struct md_rdev *read_balance(struct r10conf *conf, raid10_find_phys(conf, r10_bio); rcu_read_lock(); -retry: sectors = r10_bio->sectors; best_slot = -1; best_rdev = NULL; @@ -804,13 +803,6 @@ retry: if (slot >= 0) { atomic_inc(&rdev->nr_pending); - if (test_bit(Faulty, &rdev->flags)) { - /* Cannot risk returning a device that failed - * before we inc'ed nr_pending - */ - rdev_dec_pending(rdev, conf->mddev); - goto retry; - } r10_bio->read_slot = slot; } else rdev = NULL; |
