btrfs: add wrapper for transaction abort predicate
The status of aborted transaction can change between calls and it needs
to be accessed by READ_ONCE. Add a helper that also wraps the unlikely
hint.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 49f7196..453cea7 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -115,6 +115,10 @@ struct btrfs_trans_handle {
struct btrfs_block_rsv *orig_rsv;
refcount_t use_count;
unsigned int type;
+ /*
+ * Error code of transaction abort, set outside of locks and must use
+ * the READ_ONCE/WRITE_ONCE access
+ */
short aborted;
bool adding_csums;
bool allocating_chunk;
@@ -126,6 +130,14 @@ struct btrfs_trans_handle {
struct list_head new_bgs;
};
+/*
+ * The abort status can be changed between calls and is not protected by locks.
+ * This accepts btrfs_transaction and btrfs_trans_handle as types. Once it's
+ * set to a non-zero value it does not change, so the macro should be in checks
+ * but is not necessary for further reads of the value.
+ */
+#define TRANS_ABORTED(trans) (unlikely(READ_ONCE((trans)->aborted)))
+
struct btrfs_pending_snapshot {
struct dentry *dentry;
struct inode *dir;