[PATCH v4 2/3] reftable: adapt writer_add_record() to propagate block_writer_add() errors

[Meet Soni <meetsoni3017@gmail.com>]

    Previously, writer_add_record() would flush the current block and
    retry appending the record whenever block_writer_add() returned any
    nonzero error. This forced an assumption that every failure meant
    the block was full, even when errors such as memory allocation or I/O
    failures occurred.

    Update the writer_add_record() to inspect the error code returned by
    block_writer_add() and only flush and reinitialize the writer when the
    error is REFTABLE_ENTRY_TOO_BIG_ERROR. For any other error, immediately
    propagate it.

Signed-off-by: Meet Soni <meetsoni3017@gmail.com>
---
 reftable/writer.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/reftable/writer.c b/reftable/writer.c
index f3ab1035d6..94c97b7ac0 100644
--- a/reftable/writer.c
+++ b/reftable/writer.c
@@ -310,11 +310,12 @@ static int writer_add_record(struct reftable_writer *w,
 	 * done. Otherwise the block writer may have hit the block size limit
 	 * and needs to be flushed.
 	 */
-	if (!block_writer_add(w->block_writer, rec)) {
-		err = 0;
+	err = block_writer_add(w->block_writer, rec);
+	if (err == 0)
 		goto done;
-	}
 
+	if (err != REFTABLE_ENTRY_TOO_BIG_ERROR)
+		goto done;
 	/*
 	 * The current block is full, so we need to flush and reinitialize the
 	 * writer to start writing the next block.
@@ -329,16 +330,10 @@ static int writer_add_record(struct reftable_writer *w,
 	/*
 	 * Try to add the record to the writer again. If this still fails then
 	 * the record does not fit into the block size.
-	 *
-	 * TODO: it would be great to have `block_writer_add()` return proper
-	 *       error codes so that we don't have to second-guess the failure
-	 *       mode here.
 	 */
 	err = block_writer_add(w->block_writer, rec);
-	if (err) {
-		err = REFTABLE_ENTRY_TOO_BIG_ERROR;
+	if (err)
 		goto done;
-	}
 
 done:
 	return err;
-- 
2.34.1