From 5588383ece6127909df5b9d601d562fe5b9fe38a Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Tue, 24 Jun 2014 15:39:16 +0800 Subject: Btrfs: fix crash when mounting raid5 btrfs with missing disks The reproducer is $ mkfs.btrfs D1 D2 D3 -mraid5 $ mkfs.ext4 D2 && mkfs.ext4 D3 $ mount D1 /btrfs -odegraded ------------------- [ 87.672992] ------------[ cut here ]------------ [ 87.673845] kernel BUG at fs/btrfs/raid56.c:1828! ... [ 87.673845] RIP: 0010:[] [] __raid_recover_end_io+0x4ae/0x4d0 ... [ 87.673845] Call Trace: [ 87.673845] [] ? mempool_free+0x36/0xa0 [ 87.673845] [] raid_recover_end_io+0x75/0xa0 [ 87.673845] [] bio_endio+0x5b/0xa0 [ 87.673845] [] bio_endio_nodec+0x12/0x20 [ 87.673845] [] end_workqueue_fn+0x41/0x50 [ 87.673845] [] normal_work_helper+0xca/0x2c0 [ 87.673845] [] process_one_work+0x1eb/0x530 [ 87.673845] [] ? process_one_work+0x189/0x530 [ 87.673845] [] worker_thread+0x11b/0x4f0 [ 87.673845] [] ? rescuer_thread+0x290/0x290 [ 87.673845] [] kthread+0xe4/0x100 [ 87.673845] [] ? kthread_create_on_node+0x220/0x220 [ 87.673845] [] ret_from_fork+0x7c/0xb0 [ 87.673845] [] ? kthread_create_on_node+0x220/0x220 ------------------- It's because that we miscalculate @rbio->bbio->error so that it doesn't reach maximum of tolerable errors while it should have. Signed-off-by: Liu Bo Tested-by: Satoru Takeuchi Signed-off-by: Chris Mason --- fs/btrfs/raid56.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index 4055291a523e..4a88f073fdd7 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -1956,9 +1956,10 @@ static int __raid56_parity_recover(struct btrfs_raid_bio *rbio) * pages are going to be uptodate. */ for (stripe = 0; stripe < bbio->num_stripes; stripe++) { - if (rbio->faila == stripe || - rbio->failb == stripe) + if (rbio->faila == stripe || rbio->failb == stripe) { + atomic_inc(&rbio->bbio->error); continue; + } for (pagenr = 0; pagenr < nr_pages; pagenr++) { struct page *p; -- cgit v1.2.3