While fixing the failing ASSERT in device replace finishing procedure I also found several oddities/bugs. Here is the resultant pile.
First 3 patches are a couple simple cleanups. Patch 4 fixes a real bug since btrfs_init_dev_replace_tgtdev accesses values which might be updated by transaction commit, so naturally it should be called after the transaction is actually committed. I think this should go to stable. Patch 5 cleanups unlocking code in btrfs_dev_replace_start removing a goto label and a local variable. Patch 6 also fixes a bug, since persisting the dev-replace item relied on global reserve being able to satisfy the condition. While this is not wrong per-se I find it somewhat subtle, so just be explicit and start a transaction with reservation for at least 1 item. Patch 7 fixes the race condition which caused the newly added ASSERT to trigger. I've added the Fixes: tag to point to the first commit which introduced taking chunk_mutex. This is also stable material. Patch 8 is also a minor cleanup, just removing what I believe to be a redundant assignment. This series went under multiple xfstest runs and no regressions were observed. Nikolay Borisov (8): btrfs: Don't opencode sync_blockdev in btrfs_init_dev_replace_tgtdev btrfs: Reduce critical section in btrfs_init_dev_replace_tgtdev btrfs: Remove impossible WARN_ON btrfs: Ensure btrfs_init_dev_replace_tgtdev sees up to date values btrfs: Streamline replace sem unlock in btrfs_dev_replace_start btrfs: Explicitly reserve space for devreplace item btrfs: Ensure replaced device doesn't have pending chunk allocation btrfs: Remove redundant assignment of tgt_device->commit_total_bytes fs/btrfs/dev-replace.c | 59 +++++++++++++++++++++++------------------- 1 file changed, 32 insertions(+), 27 deletions(-) -- 2.17.1
