From dba034eef2456d2a9f9a76806846c97acf6c3ad1 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 5 Aug 2008 15:54:13 +1000 Subject: Fail safely when trying to grow an array with a write-intent bitmap. We cannot currently change the size of a write-intent bitmap. So if we change the size of an array which has such a bitmap, it tries to set bits beyond the end of the bitmap. For now, simply reject any request to change the size of an array which has a bitmap. mdadm can remove the bitmap and add a new one after the array has changed size. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/md/raid5.c') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 40e939675657..17e0953c3c06 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4446,6 +4446,9 @@ static int raid5_check_reshape(mddev_t *mddev) return -EINVAL; /* Cannot shrink array or change level yet */ if (mddev->delta_disks == 0) return 0; /* nothing to do */ + if (mddev->bitmap) + /* Cannot grow a bitmap yet */ + return -EBUSY; /* Can only proceed if there are plenty of stripe_heads. * We need a minimum of one full stripe,, and for sensible progress -- cgit From ac4090d24c6a26211bc4523d920376e054d4f3f8 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 5 Aug 2008 15:54:13 +1000 Subject: Don't let a blocked_rdev interfere with read request in raid5/6 When we have externally managed metadata, we need to mark a failed device as 'Blocked' and not allow any writes until that device have been marked as faulty in the metadata and the Blocked flag has been removed. However it is perfectly OK to allow read requests when there is a Blocked device, and with a readonly array, there may not be any metadata-handler watching for blocked devices. So in raid5/raid6 only allow a Blocked device to interfere with Write request or resync. Read requests go through untouched. raid1 and raid10 already differentiate between read and write properly. Signed-off-by: NeilBrown --- drivers/md/raid5.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) (limited to 'drivers/md/raid5.c') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 17e0953c3c06..224de022e7c5 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2568,10 +2568,10 @@ static bool handle_stripe5(struct stripe_head *sh) if (dev->written) s.written++; rdev = rcu_dereference(conf->disks[i].rdev); - if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { + if (blocked_rdev == NULL && + rdev && unlikely(test_bit(Blocked, &rdev->flags))) { blocked_rdev = rdev; atomic_inc(&rdev->nr_pending); - break; } if (!rdev || !test_bit(In_sync, &rdev->flags)) { /* The ReadError flag will just be confusing now */ @@ -2588,8 +2588,14 @@ static bool handle_stripe5(struct stripe_head *sh) rcu_read_unlock(); if (unlikely(blocked_rdev)) { - set_bit(STRIPE_HANDLE, &sh->state); - goto unlock; + if (s.syncing || s.expanding || s.expanded || + s.to_write || s.written) { + set_bit(STRIPE_HANDLE, &sh->state); + goto unlock; + } + /* There is nothing for the blocked_rdev to block */ + rdev_dec_pending(blocked_rdev, conf->mddev); + blocked_rdev = NULL; } if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) { @@ -2832,10 +2838,10 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page) if (dev->written) s.written++; rdev = rcu_dereference(conf->disks[i].rdev); - if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { + if (blocked_rdev == NULL && + rdev && unlikely(test_bit(Blocked, &rdev->flags))) { blocked_rdev = rdev; atomic_inc(&rdev->nr_pending); - break; } if (!rdev || !test_bit(In_sync, &rdev->flags)) { /* The ReadError flag will just be confusing now */ @@ -2853,9 +2859,16 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page) rcu_read_unlock(); if (unlikely(blocked_rdev)) { - set_bit(STRIPE_HANDLE, &sh->state); - goto unlock; + if (s.syncing || s.expanding || s.expanded || + s.to_write || s.written) { + set_bit(STRIPE_HANDLE, &sh->state); + goto unlock; + } + /* There is nothing for the blocked_rdev to block */ + rdev_dec_pending(blocked_rdev, conf->mddev); + blocked_rdev = NULL; } + pr_debug("locked=%d uptodate=%d to_read=%d" " to_write=%d failed=%d failed_num=%d,%d\n", s.locked, s.uptodate, s.to_read, s.to_write, s.failed, -- cgit