usr/src/cmd/sendmail/db/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     10.24 (Sleepycat) 9/27/98";
  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         MP_PANIC_CHECK(dbmp);
  44
  45         /* Validate arguments. */
  46         if (flags) {
  47                 if ((ret = __db_fchk(dbmp->dbenv, "memp_fput", flags,
  48                     DB_MPOOL_CLEAN | DB_MPOOL_DIRTY | DB_MPOOL_DISCARD)) != 0)
  49                         return (ret);
  50                 if ((ret = __db_fcchk(dbmp->dbenv, "memp_fput",
  51                     flags, DB_MPOOL_CLEAN, DB_MPOOL_DIRTY)) != 0)
  52                         return (ret);
  53
  54                 if (LF_ISSET(DB_MPOOL_DIRTY) && F_ISSET(dbmfp, MP_READONLY)) {
  55                         __db_err(dbmp->dbenv,
  56                             "%s: dirty flag set for readonly file page",
  57                             __memp_fn(dbmfp));
  58                         return (EACCES);
  59                 }
  60         }
  61
  62         LOCKREGION(dbmp);
  63
  64         /* Decrement the pinned reference count. */
  65         if (dbmfp->pinref == 0)
  66                 __db_err(dbmp->dbenv,
  67                     "%s: put: more blocks returned than retrieved",
  68                     __memp_fn(dbmfp));
  69         else
  70                 --dbmfp->pinref;
  71
  72         /*
  73          * If we're mapping the file, there's nothing to do.  Because we can
  74          * stop mapping the file at any time, we have to check on each buffer
  75          * to see if the address we gave the application was part of the map
  76          * region.
  77          */
  78         if (dbmfp->addr != NULL && pgaddr >= dbmfp->addr &&
  79             (u_int8_t *)pgaddr <= (u_int8_t *)dbmfp->addr + dbmfp->len) {
  80                 UNLOCKREGION(dbmp);
  81                 return (0);
  82         }
  83
  84         /* Convert the page address to a buffer header. */
  85         bhp = (BH *)((u_int8_t *)pgaddr - SSZA(BH, buf));
  86
  87         /* Set/clear the page bits. */
  88         if (LF_ISSET(DB_MPOOL_CLEAN) && F_ISSET(bhp, BH_DIRTY)) {
  89                 ++mp->stat.st_page_clean;
  90                 --mp->stat.st_page_dirty;
  91                 F_CLR(bhp, BH_DIRTY);
  92         }
  93         if (LF_ISSET(DB_MPOOL_DIRTY) && !F_ISSET(bhp, BH_DIRTY)) {
  94                 --mp->stat.st_page_clean;
  95                 ++mp->stat.st_page_dirty;
  96                 F_SET(bhp, BH_DIRTY);
  97         }
  98         if (LF_ISSET(DB_MPOOL_DISCARD))
  99                 F_SET(bhp, BH_DISCARD);
 100
 101         /*
 102          * Check for a reference count going to zero.  This can happen if the
 103          * application returns a page twice.
 104          */
 105         if (bhp->ref == 0) {
 106                 __db_err(dbmp->dbenv, "%s: page %lu: unpinned page returned",
 107                     __memp_fn(dbmfp), (u_long)bhp->pgno);
 108                 UNLOCKREGION(dbmp);
 109                 return (EINVAL);
 110         }
 111
 112         /*
 113          * If more than one reference to the page, we're done.  Ignore the
 114          * discard flags (for now) and leave it at its position in the LRU
 115          * chain.  The rest gets done at last reference close.
 116          */
 117         if (--bhp->ref > 0) {
 118                 UNLOCKREGION(dbmp);
 119                 return (0);
 120         }
 121
 122         /* Move the buffer to the head/tail of the LRU chain. */
 123         SH_TAILQ_REMOVE(&mp->bhq, bhp, q, __bh);
 124         if (F_ISSET(bhp, BH_DISCARD))
 125                 SH_TAILQ_INSERT_HEAD(&mp->bhq, bhp, q, __bh);
 126         else
 127                 SH_TAILQ_INSERT_TAIL(&mp->bhq, bhp, q);
 128
 129         /*
 130          * If this buffer is scheduled for writing because of a checkpoint, we
 131          * need to write it (if we marked it dirty), or update the checkpoint
 132          * counters (if we didn't mark it dirty).  If we try to write it and
 133          * can't, that's not necessarily an error, but set a flag so that the
 134          * next time the memp_sync function runs we try writing it there, as
 135          * the checkpoint application better be able to write all of the files.
 136          */
 137         if (F_ISSET(bhp, BH_WRITE))
 138                 if (F_ISSET(bhp, BH_DIRTY)) {
 139                         if (__memp_bhwrite(dbmp,
 140                             dbmfp->mfp, bhp, NULL, &wrote) != 0 || !wrote)
 141                                 F_SET(mp, MP_LSN_RETRY);
 142                 } else {
 143                         F_CLR(bhp, BH_WRITE);
 144
 145                         --dbmfp->mfp->lsn_cnt;
 146                         --mp->lsn_cnt;
 147                 }
 148
 149         UNLOCKREGION(dbmp);
 150         return (0);
 151 }