btrfs: copy devid in btrfs_partially_delete_raid_extent()

When btrfs_partially_delete_raid_extent() rebuilds a truncated/shifted
stripe extent into newitem, the loop copies the physical address for
each stride but forgets to copy the devid. The resulting item written
back to the stripe tree has zeroed-out devids, corrupting the stripe
mapping.

Fix this by reading the devid with btrfs_raid_stride_devid() and
writing it into the new item with btrfs_set_stack_raid_stride_devid()
before copying the physical address.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: robbieko <robbieko@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/raid-stripe-tree.c b/fs/btrfs/raid-stripe-tree.c
index 638c4ad572c9963d588b88c4bbe0b27ea53e0c1e..ac8cec3ce6d34f5895ea27648bc36aeb3a22e5c2 100644 (file)
--- a/fs/btrfs/raid-stripe-tree.c
+++ b/fs/btrfs/raid-stripe-tree.c
@@ -45,8 +45,11 @@ static int btrfs_partially_delete_raid_extent(struct btrfs_trans_handle *trans,
 
        for (int i = 0; i < btrfs_num_raid_stripes(item_size); i++) {
                struct btrfs_raid_stride *stride = &extent->strides[i];
+               u64 devid;
                u64 phys;
 
+               devid = btrfs_raid_stride_devid(leaf, stride);
+               btrfs_set_stack_raid_stride_devid(&newitem->strides[i], devid);
                phys = btrfs_raid_stride_physical(leaf, stride) + frontpad;
                btrfs_set_stack_raid_stride_physical(&newitem->strides[i], phys);
        }