fix unlock bug in shmem logio when no spill available

TEST_CHECKPATCH_SKIP_FILES="common/src/unifyfs_configurator.h"

common/src/unifyfs_logio.c

@@ -586,24 +586,32 @@ int unifyfs_logio_alloc(logio_context* ctx,
  return UNIFYFS_SUCCESS;
  }
 
- /* could not get full allocation in shmem, reserve any available
- * chunks at the end of the shmem log */
- size_t log_end_chunks = chunkmap->total_slots -
- (chunkmap->last_used_slot + 1);
- if (log_end_chunks > 0) {
- res_chunks = log_end_chunks;
- res_slot = slotmap_reserve(chunkmap, res_chunks);
- if (-1 != res_slot) {
- /* reserved all chunks at end of shmem log */
- allocated_bytes = res_chunks * chunk_sz;
- needed_bytes -= allocated_bytes;
- res_off = (off_t)(res_slot * chunk_sz);
- mem_allocation = allocated_bytes;
- mem_res_slot = res_slot;
- mem_res_nchk = res_chunks;
- mem_res_at_end = 1;
+ if (NULL != ctx->spill_hdr) {
+ /* could not get full allocation in shmem, try to reserve any
+ * available chunks at the end of the shmem log before asking
+ * for chunks at the beginning of the spill log */
+ size_t log_end_chunks = chunkmap->total_slots -
+ (chunkmap->last_used_slot + 1);
+ if (log_end_chunks > 0) {
+ res_chunks = log_end_chunks;
+ res_slot = slotmap_reserve(chunkmap, res_chunks);
+ if (-1 != res_slot) {
+ /* reserved all chunks at end of shmem log */
+ allocated_bytes = res_chunks * chunk_sz;
+ needed_bytes -= allocated_bytes;
+ res_off = (off_t)(res_slot * chunk_sz);
+ mem_allocation = allocated_bytes;
+ mem_res_slot = res_slot;
+ mem_res_nchk = res_chunks;
+ mem_res_at_end = 1;
+ }
  }
- } else {
+ }
+
+ /* NOTE: when we have a reservation of chunks at the end of the shmem
+ * log we don't unlock the shmem_hdr here because we need to
+ * keep it locked through the spill alloc attempt */
+ if (!mem_res_at_end) {
  UNLOCK_LOG_HEADER(shmem_hdr);
  }
  }