Btrfs: stop waiting on current trans if we aborted

I hit a hang when run_delayed_refs returned an error in the beginning of
btrfs_commit_transaction.  If we decide we need to commit the transaction in
btrfs_end_transaction we'll set BLOCKED and start to commit, but if we get an
error this early on we'll just exit without committing.  This is fine, except
that anybody else who tried to start a transaction will sit in
wait_current_trans() since we're set to BLOCKED and we never set it to something
else and woke people up.  To fix this we want to check for trans->aborted
everywhere we wait for the transaction state to change, and make
btrfs_abort_transaction() wake up any waiters there may be.  All the callers
will notice that the transaction has aborted and exit out properly.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 14d2be03f95a1c191b03cf017f6e8b42c0feaef1..8eb6191d86da8c3f3bb31b838c97a755f5c96853 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -265,6 +265,9 @@ void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
                return;
        }
        ACCESS_ONCE(trans->transaction->aborted) = errno;
+       /* Wake up anybody who may be waiting on this transaction */
+       wake_up(&root->fs_info->transaction_wait);
+       wake_up(&root->fs_info->transaction_blocked_wait);
        __btrfs_std_error(root->fs_info, function, line, errno, NULL);
 }
 /*

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 8c8b80085e754e242f759f242a77289c54da2972..c11b7efcc561c8150f69bf1c013b259e9e8df5ef 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -302,7 +302,8 @@ int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
 static inline int is_transaction_blocked(struct btrfs_transaction *trans)
 {
        return (trans->state >= TRANS_STATE_BLOCKED &&
-               trans->state < TRANS_STATE_UNBLOCKED);
+               trans->state < TRANS_STATE_UNBLOCKED &&
+               !trans->aborted);
 }
 
 /* wait for commit against the current transaction to become unblocked
@@ -320,7 +321,8 @@ static void wait_current_trans(struct btrfs_root *root)
                spin_unlock(&root->fs_info->trans_lock);
 
                wait_event(root->fs_info->transaction_wait,
-                          cur_trans->state >= TRANS_STATE_UNBLOCKED);
+                          cur_trans->state >= TRANS_STATE_UNBLOCKED ||
+                          cur_trans->aborted);
                put_transaction(cur_trans);
        } else {
                spin_unlock(&root->fs_info->trans_lock);
@@ -1392,7 +1394,8 @@ static void wait_current_trans_commit_start(struct btrfs_root *root,
                                            struct btrfs_transaction *trans)
 {
        wait_event(root->fs_info->transaction_blocked_wait,
-                  trans->state >= TRANS_STATE_COMMIT_START);
+                  trans->state >= TRANS_STATE_COMMIT_START ||
+                  trans->aborted);
 }
 
 /*
@@ -1403,7 +1406,8 @@ static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root,
                                         struct btrfs_transaction *trans)
 {
        wait_event(root->fs_info->transaction_wait,
-                  trans->state >= TRANS_STATE_UNBLOCKED);
+                  trans->state >= TRANS_STATE_UNBLOCKED ||
+                  trans->aborted);
 }
 
 /*