From bbfa57c0f2243a7c31fd248d22e9861a2802cad5 Mon Sep 17 00:00:00 2001 From: Sebastian Riemer Date: Thu, 21 Feb 2013 13:28:09 +1100 Subject: md: protect against crash upon fsync on ro array If an fsync occurs on a read-only array, we need to send a completion for the IO and may not increment the active IO count. Otherwise, we hit a bug trace and can't stop the MD array anymore. By advice of Christoph Hellwig we return success upon a flush request but we return -EROFS for other writes. We detect flush requests by checking if the bio has zero sectors. This patch is suitable to any -stable kernel to which it applies. Cc: Christoph Hellwig Cc: Ben Hutchings Cc: NeilBrown Cc: stable@vger.kernel.org Signed-off-by: Sebastian Riemer Reported-by: Ben Hutchings Acked-by: Paul Menzel Signed-off-by: NeilBrown --- drivers/md/md.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/md/md.c') diff --git a/drivers/md/md.c b/drivers/md/md.c index 3db3d1b271f7..1e634a68541e 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -307,6 +307,10 @@ static void md_make_request(struct request_queue *q, struct bio *bio) bio_io_error(bio); return; } + if (mddev->ro == 1 && unlikely(rw == WRITE)) { + bio_endio(bio, bio_sectors(bio) == 0 ? 0 : -EROFS); + return; + } smp_rmb(); /* Ensure implications of 'active' are visible */ rcu_read_lock(); if (mddev->suspended) { -- cgit v1.2.3 From a64685399181780998281fe07309a94b25dd24c3 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 21 Feb 2013 14:33:17 +1100 Subject: md: fix two bugs when attempting to resize RAID0 array. You cannot resize a RAID0 array (in terms of making the devices bigger), but the code doesn't entirely stop you. So: disable setting of the available size on each device for RAID0 and Linear devices. This must not change as doing so can change the effective layout of data. Make sure that the size that raid0_size() reports is accurate, but rounding devices sizes to chunk sizes. As the device sizes cannot change now, this isn't so important, but it is best to be safe. Without this change: mdadm --grow /dev/md0 -z max mdadm --grow /dev/md0 -Z max then read to the end of the array can cause a BUG in a RAID0 array. These bugs have been present ever since it became possible to resize any device, which is a long time. So the fix is suitable for any -stable kerenl. Cc: stable@vger.kernel.org Signed-off-by: NeilBrown --- drivers/md/md.c | 3 +++ drivers/md/raid0.c | 3 ++- 2 files changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/md/md.c') diff --git a/drivers/md/md.c b/drivers/md/md.c index 1e634a68541e..f363135144f6 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2998,6 +2998,9 @@ rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len) } else if (!sectors) sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) - rdev->data_offset; + if (!my_mddev->pers->resize) + /* Cannot change size for RAID0 or Linear etc */ + return -EINVAL; } if (sectors < my_mddev->dev_sectors) return -EINVAL; /* component must fit device */ diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index 24b359717a7e..15c8d3505450 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -411,7 +411,8 @@ static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks "%s does not support generic reshape\n", __func__); rdev_for_each(rdev, mddev) - array_sectors += rdev->sectors; + array_sectors += (rdev->sectors & + ~(sector_t)(mddev->chunk_sectors-1)); return array_sectors; } -- cgit v1.2.3 From f3378b48705154b9089affb2d2e939622aea68f1 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 28 Feb 2013 11:59:03 +1100 Subject: md: expedite metadata update when switching read-auto -> active If something has failed while the array was read-auto, then when we switch to 'active' we need to update the metadata. This will happen anyway but it is good to expedite it, and also to ensure any failed device has been released by the underlying device before we try to action the ioctl which caused us to switch to 'active' mode. Reported-by: Joe Lawrence Signed-off-by: NeilBrown --- drivers/md/md.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'drivers/md/md.c') diff --git a/drivers/md/md.c b/drivers/md/md.c index f363135144f6..fcb878f88796 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -6532,7 +6532,17 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode, mddev->ro = 0; sysfs_notify_dirent_safe(mddev->sysfs_state); set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); - md_wakeup_thread(mddev->thread); + /* mddev_unlock will wake thread */ + /* If a device failed while we were read-only, we + * need to make sure the metadata is updated now. + */ + if (test_bit(MD_CHANGE_DEVS, &mddev->flags)) { + mddev_unlock(mddev); + wait_event(mddev->sb_wait, + !test_bit(MD_CHANGE_DEVS, &mddev->flags) && + !test_bit(MD_CHANGE_PENDING, &mddev->flags)); + mddev_lock(mddev); + } } else { err = -EROFS; goto abort_unlock; -- cgit v1.2.3