xref: /titanic_41/usr/src/cmd/sendmail/db/mp/mp_fput.c (revision c037192b037119c9fd354732fc29b38ce097d356)
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 }
152