Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux...

[pandora-kernel.git] / fs / btrfs / volumes.c

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 0b4e2af..ef41f28 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -459,12 +459,23 @@ int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
 {
        struct btrfs_device *device, *next;
 
+       struct block_device *latest_bdev = NULL;
+       u64 latest_devid = 0;
+       u64 latest_transid = 0;
+
        mutex_lock(&uuid_mutex);
 again:
        /* This is the initialized path, it is safe to release the devices. */
        list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
-               if (device->in_fs_metadata)
+               if (device->in_fs_metadata) {
+                       if (!latest_transid ||
+                           device->generation > latest_transid) {
+                               latest_devid = device->devid;
+                               latest_transid = device->generation;
+                               latest_bdev = device->bdev;
+                       }
                        continue;
+               }
 
                if (device->bdev) {
                        blkdev_put(device->bdev, device->mode);
@@ -487,6 +498,10 @@ again:
                goto again;
        }
 
+       fs_devices->latest_bdev = latest_bdev;
+       fs_devices->latest_devid = latest_devid;
+       fs_devices->latest_trans = latest_transid;
+
        mutex_unlock(&uuid_mutex);
        return 0;
 }
@@ -1953,7 +1968,7 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
        em = lookup_extent_mapping(em_tree, chunk_offset, 1);
        read_unlock(&em_tree->lock);
 
-       BUG_ON(em->start > chunk_offset ||
+       BUG_ON(!em || em->start > chunk_offset ||
               em->start + em->len < chunk_offset);
        map = (struct map_lookup *)em->bdev;
 
@@ -4356,6 +4371,20 @@ int btrfs_read_sys_array(struct btrfs_root *root)
                return -ENOMEM;
        btrfs_set_buffer_uptodate(sb);
        btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
+       /*
+        * The sb extent buffer is artifical and just used to read the system array.
+        * btrfs_set_buffer_uptodate() call does not properly mark all it's
+        * pages up-to-date when the page is larger: extent does not cover the
+        * whole page and consequently check_page_uptodate does not find all
+        * the page's extents up-to-date (the hole beyond sb),
+        * write_extent_buffer then triggers a WARN_ON.
+        *
+        * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
+        * but sb spans only this function. Add an explicit SetPageUptodate call
+        * to silence the warning eg. on PowerPC 64.
+        */
+       if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
+               SetPageUptodate(sb->first_page);
 
        write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
        array_size = btrfs_super_sys_array_size(super_copy);