Btrfs: Allocator fix variety pack

* Force chunk allocation when find_free_extent has to do a full scan
* Record the max key at the start of defrag so it doesn't run forever
* Block groups might not be contiguous, make a forward search for the
  next block group in extent-tree.c
* Get rid of extra checks for total fs size
* Fix relocate_one_reference to avoid relocating the same file data block
  twice when referenced by an older transaction
* Use the open device count when allocating chunks so that we don't
  try to allocate from devices that don't exist

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 4 insertions, 8 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 333e5269577a..722eb4550154 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -750,10 +750,6 @@ static int btrfs_rm_dev_item(struct btrfs_root *root,
         if (bdev == fs_devices->latest_bdev)
                 fs_devices->latest_bdev = next_dev->bdev;
 
-        total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
-        btrfs_set_super_total_bytes(&root->fs_info->super_copy,
-                                    total_bytes - device->total_bytes);
-
         total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
         btrfs_set_super_num_devices(&root->fs_info->super_copy,
                                     total_bytes - 1);
@@ -849,6 +845,7 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
 
         }
         root->fs_info->fs_devices->num_devices--;
+        root->fs_info->fs_devices->open_devices--;
 
         ret = btrfs_shrink_device(device, 0);
         if (ret)
@@ -873,7 +870,6 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
         if (device->bdev) {
                 /* one close for the device struct or super_block */
                 close_bdev_excl(device->bdev);
-                root->fs_info->fs_devices->open_devices--;
         }
         if (bdev) {
                 /* one close for us */
@@ -1450,7 +1446,7 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                 return -ENOSPC;
 
         if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
-                num_stripes = btrfs_super_num_devices(&info->super_copy);
+                num_stripes = extent_root->fs_info->fs_devices->open_devices;
                 min_stripes = 2;
         }
         if (type & (BTRFS_BLOCK_GROUP_DUP)) {
@@ -1459,13 +1455,13 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
         }
         if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
                 num_stripes = min_t(u64, 2,
-                                  btrfs_super_num_devices(&info->super_copy));
+                            extent_root->fs_info->fs_devices->open_devices);
                 if (num_stripes < 2)
                         return -ENOSPC;
                 min_stripes = 2;
         }
         if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
-                num_stripes = btrfs_super_num_devices(&info->super_copy);
+                num_stripes = extent_root->fs_info->fs_devices->open_devices;
                 if (num_stripes < 4)
                         return -ENOSPC;
                 num_stripes &= ~(u32)1;