btrfs: replace many BUG_ONs with proper error handling

 btrfs currently handles most errors with BUG_ON. This patch is a work-in-
 progress but aims to handle most errors other than internal logic
 errors and ENOMEM more gracefully.

 This iteration prevents most crashes but can run into lockups with
 the page lock on occasion when the timing "works out."

Signed-off-by: Jeff Mahoney <jeffm@suse.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 794cbb52f308..0209d8a9ae39 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1505,6 +1505,9 @@ static noinline_for_stack int scrub_supers(struct scrub_dev *sdev)
         struct btrfs_device *device = sdev->dev;
         struct btrfs_root *root = device->dev_root;
 
+        if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
+                return -EIO;
+
         gen = root->fs_info->last_trans_committed;
 
         for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {