From 4e59ca7da05f0d5d3ad40365c502c8b0fd24c7e3 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sat, 12 Dec 2009 21:17:06 -0700 Subject: [PATCH] md: rcu_read_lock() walk of mddev->disks in md_do_sync() Other walks of this list are either under rcu_read_lock() or the list mutation lock (mddev_lock()). This protects against the improbable case of a disk being removed from the array at the start of md_do_sync(). Signed-off-by: Dan Williams --- drivers/md/md.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 68a8a29a901..ea64a68e9c7 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -6526,12 +6526,14 @@ void md_do_sync(mddev_t *mddev) /* recovery follows the physical size of devices */ max_sectors = mddev->dev_sectors; j = MaxSector; - list_for_each_entry(rdev, &mddev->disks, same_set) + rcu_read_lock(); + list_for_each_entry_rcu(rdev, &mddev->disks, same_set) if (rdev->raid_disk >= 0 && !test_bit(Faulty, &rdev->flags) && !test_bit(In_sync, &rdev->flags) && rdev->recovery_offset < j) j = rdev->recovery_offset; + rcu_read_unlock(); } printk(KERN_INFO "md: %s of RAID array %s\n", desc, mdname(mddev)); @@ -6701,12 +6703,14 @@ void md_do_sync(mddev_t *mddev) } else { if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) mddev->curr_resync = MaxSector; - list_for_each_entry(rdev, &mddev->disks, same_set) + rcu_read_lock(); + list_for_each_entry_rcu(rdev, &mddev->disks, same_set) if (rdev->raid_disk >= 0 && !test_bit(Faulty, &rdev->flags) && !test_bit(In_sync, &rdev->flags) && rdev->recovery_offset < mddev->curr_resync) rdev->recovery_offset = mddev->curr_resync; + rcu_read_unlock(); } } set_bit(MD_CHANGE_DEVS, &mddev->flags);