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authorNeilBrown <neilb@suse.com>2016-06-02 16:19:52 +1000
committerShaohua Li <shli@fb.com>2016-06-13 11:54:14 -0700
commitd44b0a928fa9925fb453d7acc42a48c79de2c6f7 (patch)
tree24351c0d633aeec643c7f39ef6642096d4255dc3 /drivers/md
parent83f1261f5e5516d7cf58a04b97e4e63e747a9157 (diff)
downloadop-kernel-dev-d44b0a928fa9925fb453d7acc42a48c79de2c6f7.zip
op-kernel-dev-d44b0a928fa9925fb453d7acc42a48c79de2c6f7.tar.gz
md/raid10: add rcu protection in raid10_status.
mirrors[].rdev can become NULL at any point unless: - a counted reference is held - ->reconfig_mutex is held, or - rcu_read_lock() is held raid10_status holds none of these. So add rcu_read_lock() protection. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/raid10.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 6044864..334a701 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1495,10 +1495,12 @@ static void raid10_status(struct seq_file *seq, struct mddev *mddev)
}
seq_printf(seq, " [%d/%d] [", conf->geo.raid_disks,
conf->geo.raid_disks - mddev->degraded);
- for (i = 0; i < conf->geo.raid_disks; i++)
- seq_printf(seq, "%s",
- conf->mirrors[i].rdev &&
- test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
+ rcu_read_lock();
+ for (i = 0; i < conf->geo.raid_disks; i++) {
+ struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ seq_printf(seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
+ }
+ rcu_read_unlock();
seq_printf(seq, "]");
}
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