db2/mp/mp_fput.c

   1 /*-
   2  * See the file LICENSE for redistribution information.
   3  *
   4  * Copyright (c) 1996, 1997, 1998
   5  *      Sleepycat Software.  All rights reserved.
   6  */
   7 #include "config.h"
   8
   9 #ifndef lint
  10 static const char sccsid[] = "@(#)mp_fput.c     10.22 (Sleepycat) 4/26/98";
  11 #endif /* not lint */
  12
  13 #ifndef NO_SYSTEM_INCLUDES
  14 #include <sys/types.h>
  15
  16 #include <errno.h>
  17 #endif
  18
  19 #include "db_int.h"
  20 #include "shqueue.h"
  21 #include "db_shash.h"
  22 #include "mp.h"
  23 #include "common_ext.h"
  24
  25 /*
  26  * memp_fput --
  27  *      Mpool file put function.
  28  */
  29 int
  30 memp_fput(dbmfp, pgaddr, flags)
  31         DB_MPOOLFILE *dbmfp;
  32         void *pgaddr;
  33         u_int32_t flags;
  34 {
  35         BH *bhp;
  36         DB_MPOOL *dbmp;
  37         MPOOL *mp;
  38         int wrote, ret;
  39
  40         dbmp = dbmfp->dbmp;
  41         mp = dbmp->mp;
  42
  43         /* Validate arguments. */
  44         if (flags) {
  45                 if ((ret = __db_fchk(dbmp->dbenv, "memp_fput", flags,
  46                     DB_MPOOL_CLEAN | DB_MPOOL_DIRTY | DB_MPOOL_DISCARD)) != 0)
  47                         return (ret);
  48                 if ((ret = __db_fcchk(dbmp->dbenv, "memp_fput",
  49                     flags, DB_MPOOL_CLEAN, DB_MPOOL_DIRTY)) != 0)
  50                         return (ret);
  51
  52                 if (LF_ISSET(DB_MPOOL_DIRTY) && F_ISSET(dbmfp, MP_READONLY)) {
  53                         __db_err(dbmp->dbenv,
  54                             "%s: dirty flag set for readonly file page",
  55                             __memp_fn(dbmfp));
  56                         return (EACCES);
  57                 }
  58         }
  59
  60         /* Decrement the pinned reference count. */
  61         LOCKHANDLE(dbmp, dbmfp->mutexp);
  62         if (dbmfp->pinref == 0)
  63                 __db_err(dbmp->dbenv,
  64                     "%s: put: more blocks returned than retrieved",
  65                     __memp_fn(dbmfp));
  66         else
  67                 --dbmfp->pinref;
  68         UNLOCKHANDLE(dbmp, dbmfp->mutexp);
  69
  70         /*
  71          * If we're mapping the file, there's nothing to do.  Because we can
  72          * stop mapping the file at any time, we have to check on each buffer
  73          * to see if the address we gave the application was part of the map
  74          * region.
  75          */
  76         if (dbmfp->addr != NULL && pgaddr >= dbmfp->addr &&
  77             (u_int8_t *)pgaddr <= (u_int8_t *)dbmfp->addr + dbmfp->len)
  78                 return (0);
  79
  80         /* Convert the page address to a buffer header. */
  81         bhp = (BH *)((u_int8_t *)pgaddr - SSZA(BH, buf));
  82
  83         LOCKREGION(dbmp);
  84
  85         /* Set/clear the page bits. */
  86         if (LF_ISSET(DB_MPOOL_CLEAN) && F_ISSET(bhp, BH_DIRTY)) {
  87                 ++mp->stat.st_page_clean;
  88                 --mp->stat.st_page_dirty;
  89                 F_CLR(bhp, BH_DIRTY);
  90         }
  91         if (LF_ISSET(DB_MPOOL_DIRTY) && !F_ISSET(bhp, BH_DIRTY)) {
  92                 --mp->stat.st_page_clean;
  93                 ++mp->stat.st_page_dirty;
  94                 F_SET(bhp, BH_DIRTY);
  95         }
  96         if (LF_ISSET(DB_MPOOL_DISCARD))
  97                 F_SET(bhp, BH_DISCARD);
  98
  99         /*
 100          * Check for a reference count going to zero.  This can happen if the
 101          * application returns a page twice.
 102          */
 103         if (bhp->ref == 0) {
 104                 __db_err(dbmp->dbenv, "%s: page %lu: unpinned page returned",
 105                     __memp_fn(dbmfp), (u_long)bhp->pgno);
 106                 UNLOCKREGION(dbmp);
 107                 return (EINVAL);
 108         }
 109
 110         /*
 111          * If more than one reference to the page, we're done.  Ignore the
 112          * discard flags (for now) and leave it at its position in the LRU
 113          * chain.  The rest gets done at last reference close.
 114          */
 115         if (--bhp->ref > 0) {
 116                 UNLOCKREGION(dbmp);
 117                 return (0);
 118         }
 119
 120         /*
 121          * If this buffer is scheduled for writing because of a checkpoint, we
 122          * need to write it (if we marked it dirty), or update the checkpoint
 123          * counters (if we didn't mark it dirty).  If we try to write it and
 124          * can't, that's not necessarily an error, but set a flag so that the
 125          * next time the memp_sync function runs we try writing it there, as
 126          * the checkpoint application better be able to write all of the files.
 127          */
 128         if (F_ISSET(bhp, BH_WRITE)) {
 129                 if (F_ISSET(bhp, BH_DIRTY)) {
 130                         if (__memp_bhwrite(dbmp,
 131                             dbmfp->mfp, bhp, NULL, &wrote) != 0 || !wrote)
 132                                 F_SET(mp, MP_LSN_RETRY);
 133                 } else {
 134                         F_CLR(bhp, BH_WRITE);
 135
 136                         --dbmfp->mfp->lsn_cnt;
 137                         --mp->lsn_cnt;
 138                 }
 139         }
 140
 141         /* Move the buffer to the head/tail of the LRU chain. */
 142         SH_TAILQ_REMOVE(&mp->bhq, bhp, q, __bh);
 143         if (F_ISSET(bhp, BH_DISCARD))
 144                 SH_TAILQ_INSERT_HEAD(&mp->bhq, bhp, q, __bh);
 145         else
 146                 SH_TAILQ_INSERT_TAIL(&mp->bhq, bhp, q);
 147
 148
 149         UNLOCKREGION(dbmp);
 150         return (0);
 151 }