RDMA/ucma: Check that device exists prior to accessing it

[pandora-kernel.git] / fs / btrfs / extent-tree.c

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 78179a3..57c4ad3 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2759,13 +2759,6 @@ again:
                goto again;
        }
 
-       /* We've already setup this transaction, go ahead and exit */
-       if (block_group->cache_generation == trans->transid &&
-           i_size_read(inode)) {
-               dcs = BTRFS_DC_SETUP;
-               goto out_put;
-       }
-
        /*
         * We want to set the generation to 0, that way if anything goes wrong
         * from here on out we know not to trust this cache when we load up next
@@ -2775,6 +2768,13 @@ again:
        ret = btrfs_update_inode(trans, root, inode);
        WARN_ON(ret);
 
+       /* We've already setup this transaction, go ahead and exit */
+       if (block_group->cache_generation == trans->transid &&
+           i_size_read(inode)) {
+               dcs = BTRFS_DC_SETUP;
+               goto out_put;
+       }
+
        if (i_size_read(inode) > 0) {
                ret = btrfs_truncate_free_space_cache(root, trans, path,
                                                      inode);
@@ -4611,7 +4611,8 @@ int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
        return 0;
 }
 
-static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
+static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end,
+                             const bool return_free_space)
 {
        struct btrfs_fs_info *fs_info = root->fs_info;
        struct btrfs_block_group_cache *cache = NULL;
@@ -4631,7 +4632,8 @@ static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
 
                if (start < cache->last_byte_to_unpin) {
                        len = min(len, cache->last_byte_to_unpin - start);
-                       btrfs_add_free_space(cache, start, len);
+                       if (return_free_space)
+                               btrfs_add_free_space(cache, start, len);
                }
 
                start += len;
@@ -4676,7 +4678,7 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
                                                   end + 1 - start, NULL);
 
                clear_extent_dirty(unpin, start, end, GFP_NOFS);
-               unpin_extent_range(root, start, end);
+               unpin_extent_range(root, start, end, true);
                cond_resched();
        }
 
@@ -5676,12 +5678,11 @@ static int __btrfs_free_reserved_extent(struct btrfs_root *root,
                return -ENOSPC;
        }
 
-       if (btrfs_test_opt(root, DISCARD))
-               ret = btrfs_discard_extent(root, start, len, NULL);
-
        if (pin)
                pin_down_extent(root, cache, start, len, 1);
        else {
+               if (btrfs_test_opt(root, DISCARD))
+                       ret = btrfs_discard_extent(root, start, len, NULL);
                btrfs_add_free_space(cache, start, len);
                btrfs_update_reserved_bytes(cache, len, RESERVE_FREE);
        }
@@ -6560,6 +6561,7 @@ void btrfs_drop_snapshot(struct btrfs_root *root,
        int err = 0;
        int ret;
        int level;
+       bool root_dropped = false;
 
        path = btrfs_alloc_path();
        if (!path) {
@@ -6709,12 +6711,22 @@ void btrfs_drop_snapshot(struct btrfs_root *root,
                free_extent_buffer(root->commit_root);
                kfree(root);
        }
+       root_dropped = true;
 out_free:
        btrfs_end_transaction_throttle(trans, tree_root);
        kfree(wc);
        btrfs_free_path(path);
 out:
-       if (err)
+       /*
+        * So if we need to stop dropping the snapshot for whatever reason we
+        * need to make sure to add it back to the dead root list so that we
+        * keep trying to do the work later.  This also cleans up roots if we
+        * don't have it in the radix (like when we recover after a power fail
+        * or unmount) so we don't leak memory.
+        */
+       if (root_dropped == false)
+               btrfs_add_dead_root(root);
+       if (err && err != -EAGAIN)
                btrfs_std_error(root->fs_info, err);
        return;
 }
@@ -7639,7 +7651,7 @@ out:
 
 int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
 {
-       return unpin_extent_range(root, start, end);
+       return unpin_extent_range(root, start, end, false);
 }
 
 int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,