Line data    Source code

       1              : /*-------------------------------------------------------------------------
       2              :  *
       3              :  * aio_target.c
       4              :  *    AIO - Functionality related to executing IO for different targets
       5              :  *
       6              :  * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
       7              :  * Portions Copyright (c) 1994, Regents of the University of California
       8              :  *
       9              :  * IDENTIFICATION
      10              :  *    src/backend/storage/aio/aio_target.c
      11              :  *
      12              :  *-------------------------------------------------------------------------
      13              :  */
      14              : 
      15              : #include "postgres.h"
      16              : 
      17              : #include "storage/aio.h"
      18              : #include "storage/aio_internal.h"
      19              : #include "storage/smgr.h"
      20              : 
      21              : 
      22              : /*
      23              :  * Registry for entities that can be the target of AIO.
      24              :  */
      25              : static const PgAioTargetInfo *pgaio_target_info[] = {
      26              :     [PGAIO_TID_INVALID] = &(PgAioTargetInfo) {
      27              :         .name = "invalid",
      28              :     },
      29              :     [PGAIO_TID_SMGR] = &aio_smgr_target_info,
      30              : };
      31              : 
      32              : 
      33              : 
      34              : /* --------------------------------------------------------------------------------
      35              :  * Public target related functions operating on IO Handles
      36              :  * --------------------------------------------------------------------------------
      37              :  */
      38              : 
      39              : bool
      40            0 : pgaio_io_has_target(PgAioHandle *ioh)
      41              : {
      42            0 :     return ioh->target != PGAIO_TID_INVALID;
      43              : }
      44              : 
      45              : /*
      46              :  * Return the name for the target associated with the IO. Mostly useful for
      47              :  * debugging/logging.
      48              :  */
      49              : const char *
      50         7238 : pgaio_io_get_target_name(PgAioHandle *ioh)
      51              : {
      52              :     /* explicitly allow INVALID here, function used by debug messages */
      53              :     Assert(ioh->target >= PGAIO_TID_INVALID && ioh->target < PGAIO_TID_COUNT);
      54              : 
      55         7238 :     return pgaio_target_info[ioh->target]->name;
      56              : }
      57              : 
      58              : /*
      59              :  * Assign a target to the IO.
      60              :  *
      61              :  * This has to be called exactly once before pgaio_io_start_*() is called.
      62              :  */
      63              : void
      64      1316121 : pgaio_io_set_target(PgAioHandle *ioh, PgAioTargetID targetid)
      65              : {
      66              :     Assert(ioh->state == PGAIO_HS_HANDED_OUT);
      67              :     Assert(ioh->target == PGAIO_TID_INVALID);
      68              : 
      69      1316121 :     ioh->target = targetid;
      70      1316121 : }
      71              : 
      72              : PgAioTargetData *
      73      4217338 : pgaio_io_get_target_data(PgAioHandle *ioh)
      74              : {
      75      4217338 :     return &ioh->target_data;
      76              : }
      77              : 
      78              : /*
      79              :  * Return a stringified description of the IO's target.
      80              :  *
      81              :  * The string is localized and allocated in the current memory context.
      82              :  */
      83              : char *
      84            0 : pgaio_io_get_target_description(PgAioHandle *ioh)
      85              : {
      86              :     /* disallow INVALID, there wouldn't be a description */
      87              :     Assert(ioh->target > PGAIO_TID_INVALID && ioh->target < PGAIO_TID_COUNT);
      88              : 
      89            0 :     return pgaio_target_info[ioh->target]->describe_identity(&ioh->target_data);
      90              : }
      91              : 
      92              : 
      93              : 
      94              : /* --------------------------------------------------------------------------------
      95              :  * Internal target related functions operating on IO Handles
      96              :  * --------------------------------------------------------------------------------
      97              :  */
      98              : 
      99              : /*
     100              :  * Internal: Check if pgaio_io_reopen() is available for the IO.
     101              :  */
     102              : bool
     103       586942 : pgaio_io_can_reopen(PgAioHandle *ioh)
     104              : {
     105              :     Assert(ioh->target > PGAIO_TID_INVALID && ioh->target < PGAIO_TID_COUNT);
     106              : 
     107       586942 :     return pgaio_target_info[ioh->target]->reopen != NULL;
     108              : }
     109              : 
     110              : /*
     111              :  * Internal: Before executing an IO outside of the context of the process the
     112              :  * IO has been staged in, the file descriptor has to be reopened - any FD
     113              :  * referenced in the IO itself, won't be valid in the separate process.
     114              :  */
     115              : void
     116       480945 : pgaio_io_reopen(PgAioHandle *ioh)
     117              : {
     118              :     Assert(ioh->target > PGAIO_TID_INVALID && ioh->target < PGAIO_TID_COUNT);
     119              :     Assert(ioh->op > PGAIO_OP_INVALID && ioh->op < PGAIO_OP_COUNT);
     120              : 
     121       480945 :     pgaio_target_info[ioh->target]->reopen(ioh);
     122       480945 : }