Update some copyright notices to become more legal compliant.
[dragonfly.git] / lib / libkvm / kvm_getswapinfo.c
1 /*
2  * Copyright (c) 1999 Matthew Dillon.  All Rights Reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided under the terms of the BSD
6  * Copyright as found in /usr/src/COPYRIGHT in the FreeBSD source tree.
7  *
8  * @(#) Copyright (c) 1999
9  * $FreeBSD: src/lib/libkvm/kvm_getswapinfo.c,v 1.10.2.4 2003/01/12 09:23:13 dillon Exp $
10  * $DragonFly: src/lib/libkvm/kvm_getswapinfo.c,v 1.4 2004/06/28 02:57:10 drhodus Exp $
11  */
12
13 #define _KERNEL_STRUCTURES
14
15 #include <sys/param.h>
16 #include <sys/time.h>
17 #include <sys/ucred.h>
18 #include <sys/stat.h>
19 #include <sys/conf.h>
20 #include <sys/blist.h>
21
22 #include <err.h>
23 #include <fcntl.h>
24 #include <kvm.h>
25 #include <nlist.h>
26 #include <paths.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <string.h>
30 #include <unistd.h>
31
32 static struct nlist kvm_swap_nl[] = {
33         { "_swapblist" },       /* new radix swap list          */
34         { "_swdevt" },          /* list of swap devices and sizes */
35         { "_nswdev" },          /* number of swap devices */
36         { "_dmmax" },           /* maximum size of a swap block */
37         { "" }
38 };
39
40 #define NL_SWAPBLIST    0
41 #define NL_SWDEVT       1
42 #define NL_NSWDEV       2
43 #define NL_DMMAX        3
44
45 static int kvm_swap_nl_cached = 0;
46 static int nswdev;
47 static int unswdev;
48 static int dmmax;
49
50 static void getswapinfo_radix(kvm_t *kd, struct kvm_swap *swap_ary,
51                               int swap_max, int flags);
52
53 #define SVAR(var) __STRING(var) /* to force expansion */
54 #define KGET(idx, var)                                                  \
55         KGET1(idx, &var, sizeof(var), SVAR(var))
56 #define KGET1(idx, p, s, msg)                                           \
57         KGET2(kvm_swap_nl[idx].n_value, p, s, msg)
58 #define KGET2(addr, p, s, msg)                                          \
59         if (kvm_read(kd, (u_long)(addr), p, s) != s)                    \
60                 warnx("cannot read %s: %s", msg, kvm_geterr(kd))
61 #define KGETN(idx, var)                                                 \
62         KGET1N(idx, &var, sizeof(var), SVAR(var))
63 #define KGET1N(idx, p, s, msg)                                          \
64         KGET2N(kvm_swap_nl[idx].n_value, p, s, msg)
65 #define KGET2N(addr, p, s, msg)                                         \
66         ((kvm_read(kd, (u_long)(addr), p, s) == s) ? 1 : 0)
67 #define KGETRET(addr, p, s, msg)                                        \
68         if (kvm_read(kd, (u_long)(addr), p, s) != s) {                  \
69                 warnx("cannot read %s: %s", msg, kvm_geterr(kd));       \
70                 return (0);                                             \
71         }
72
73 int
74 kvm_getswapinfo(
75         kvm_t *kd, 
76         struct kvm_swap *swap_ary,
77         int swap_max, 
78         int flags
79 ) {
80         int ti = 0;
81
82         /*
83          * clear cache
84          */
85         if (kd == NULL) {
86                 kvm_swap_nl_cached = 0;
87                 return(0);
88         }
89
90         /*
91          * namelist
92          */
93         if (kvm_swap_nl_cached == 0) {
94                 struct swdevt *sw;
95
96                 if (kvm_nlist(kd, kvm_swap_nl) < 0)
97                         return(-1);
98
99                 /*
100                  * required entries
101                  */
102
103                 if (
104                     kvm_swap_nl[NL_SWDEVT].n_value == 0 ||
105                     kvm_swap_nl[NL_NSWDEV].n_value == 0 ||
106                     kvm_swap_nl[NL_DMMAX].n_value == 0 ||
107                     kvm_swap_nl[NL_SWAPBLIST].n_type == 0
108                 ) {
109                         return(-1);
110                 }
111
112                 /*
113                  * get globals, type of swap
114                  */
115
116                 KGET(NL_NSWDEV, nswdev);
117                 KGET(NL_DMMAX, dmmax);
118
119                 /*
120                  * figure out how many actual swap devices are enabled
121                  */
122
123                 KGET(NL_SWDEVT, sw);
124                 for (unswdev = nswdev - 1; unswdev >= 0; --unswdev) {
125                         struct swdevt swinfo;
126
127                         KGET2(&sw[unswdev], &swinfo, sizeof(swinfo), "swinfo");
128                         if (swinfo.sw_nblks)
129                                 break;
130                 }
131                 ++unswdev;
132
133                 kvm_swap_nl_cached = 1;
134         }
135
136
137         {
138                 struct swdevt *sw;
139                 int i;
140
141                 ti = unswdev;
142                 if (ti >= swap_max)
143                         ti = swap_max - 1;
144
145                 if (ti >= 0)
146                         bzero(swap_ary, sizeof(struct kvm_swap) * (ti + 1));
147
148                 KGET(NL_SWDEVT, sw);
149                 for (i = 0; i < unswdev; ++i) {
150                         struct swdevt swinfo;
151                         int ttl;
152
153                         KGET2(&sw[i], &swinfo, sizeof(swinfo), "swinfo");
154
155                         /*
156                          * old style: everything in DEV_BSIZE'd chunks,
157                          * convert to pages.
158                          *
159                          * new style: swinfo in DEV_BSIZE'd chunks but dmmax
160                          * in pages.
161                          *
162                          * The first dmmax is never allocating to avoid 
163                          * trashing the disklabels
164                          */
165
166                         ttl = swinfo.sw_nblks - dmmax;
167
168                         if (ttl == 0)
169                                 continue;
170
171                         if (i < ti) {
172                                 swap_ary[i].ksw_total = ttl;
173                                 swap_ary[i].ksw_used = ttl;
174                                 swap_ary[i].ksw_flags = swinfo.sw_flags;
175                                 if (swinfo.sw_dev == NODEV) {
176                                         snprintf(
177                                             swap_ary[i].ksw_devname,
178                                             sizeof(swap_ary[i].ksw_devname),
179                                             "%s",
180                                             "[NFS swap]"
181                                         );
182                                 } else {
183                                         snprintf(
184                                             swap_ary[i].ksw_devname,
185                                             sizeof(swap_ary[i].ksw_devname),
186                                             "%s%s",
187                                             ((flags & SWIF_DEV_PREFIX) ? _PATH_DEV : ""),
188                                             devname(swinfo.sw_dev, S_IFCHR)
189                                         );
190                                 }
191                         }
192                         if (ti >= 0) {
193                                 swap_ary[ti].ksw_total += ttl;
194                                 swap_ary[ti].ksw_used += ttl;
195                         }
196                 }
197         }
198
199         getswapinfo_radix(kd, swap_ary, swap_max, flags);
200         return(ti);
201 }
202
203 /*
204  * scanradix() - support routine for radix scanner
205  */
206
207 #define TABME   tab, tab, ""
208
209 static int
210 scanradix(
211         blmeta_t *scan, 
212         daddr_t blk,
213         daddr_t radix,
214         daddr_t skip, 
215         daddr_t count,
216         kvm_t *kd,
217         int dmmax, 
218         int nswdev,
219         struct kvm_swap *swap_ary,
220         int swap_max,
221         int tab,
222         int flags
223 ) {
224         blmeta_t meta;
225         int ti = (unswdev >= swap_max) ? swap_max - 1 : unswdev;
226
227         KGET2(scan, &meta, sizeof(meta), "blmeta_t");
228
229         /*
230          * Terminator
231          */
232         if (meta.bm_bighint == (daddr_t)-1) {
233                 if (flags & SWIF_DUMP_TREE) {
234                         printf("%*.*s(0x%06x,%d) Terminator\n", 
235                             TABME,
236                             blk, 
237                             radix
238                         );
239                 }
240                 return(-1);
241         }
242
243         if (radix == BLIST_BMAP_RADIX) {
244                 /*
245                  * Leaf bitmap
246                  */
247                 int i;
248
249                 if (flags & SWIF_DUMP_TREE) {
250                         printf("%*.*s(0x%06x,%d) Bitmap %08x big=%d\n", 
251                             TABME,
252                             blk, 
253                             radix,
254                             (int)meta.u.bmu_bitmap,
255                             meta.bm_bighint
256                         );
257                 }
258
259                 /*
260                  * If not all allocated, count.
261                  */
262                 if (meta.u.bmu_bitmap != 0) {
263                         for (i = 0; i < BLIST_BMAP_RADIX && i < count; ++i) {
264                                 /*
265                                  * A 0 bit means allocated
266                                  */
267                                 if ((meta.u.bmu_bitmap & (1 << i))) {
268                                         int t = 0;
269
270                                         if (nswdev)
271                                                 t = (blk + i) / dmmax % nswdev;
272                                         if (t < ti)
273                                                 --swap_ary[t].ksw_used;
274                                         if (ti >= 0)
275                                                 --swap_ary[ti].ksw_used;
276                                 }
277                         }
278                 }
279         } else if (meta.u.bmu_avail == radix) {
280                 /*
281                  * Meta node if all free
282                  */
283                 if (flags & SWIF_DUMP_TREE) {
284                         printf("%*.*s(0x%06x,%d) Submap ALL-FREE {\n", 
285                             TABME,
286                             blk, 
287                             radix
288                         );
289                 }
290                 /*
291                  * Note: both dmmax and radix are powers of 2.  However, dmmax
292                  * may be larger then radix so use a smaller increment if
293                  * necessary.
294                  */
295                 {
296                         int t;
297                         int tinc = dmmax;
298
299                         while (tinc > radix)
300                                 tinc >>= 1;
301
302                         for (t = blk; t < blk + radix; t += tinc) {
303                                 int u = (nswdev) ? (t / dmmax % nswdev) : 0;
304
305                                 if (u < ti)
306                                         swap_ary[u].ksw_used -= tinc;
307                                 if (ti >= 0)
308                                         swap_ary[ti].ksw_used -= tinc;
309                         }
310                 }
311         } else if (meta.u.bmu_avail == 0) {
312                 /*
313                  * Meta node if all used
314                  */
315                 if (flags & SWIF_DUMP_TREE) {
316                         printf("%*.*s(0x%06x,%d) Submap ALL-ALLOCATED\n", 
317                             TABME,
318                             blk, 
319                             radix
320                         );
321                 }
322         } else {
323                 /*
324                  * Meta node if not all free
325                  */
326                 int i;
327                 int next_skip;
328
329                 if (flags & SWIF_DUMP_TREE) {
330                         printf("%*.*s(0x%06x,%d) Submap avail=%d big=%d {\n", 
331                             TABME,
332                             blk, 
333                             radix,
334                             (int)meta.u.bmu_avail,
335                             meta.bm_bighint
336                         );
337                 }
338
339                 radix /= BLIST_META_RADIX;
340                 next_skip = skip / BLIST_META_RADIX;
341
342                 for (i = 1; i <= skip; i += next_skip) {
343                         int r;
344                         daddr_t vcount = (count > radix) ? radix : count;
345
346                         r = scanradix(
347                             &scan[i],
348                             blk,
349                             radix,
350                             next_skip - 1,
351                             vcount,
352                             kd,
353                             dmmax,
354                             nswdev,
355                             swap_ary,
356                             swap_max,
357                             tab + 4,
358                             flags
359                         );
360                         if (r < 0)
361                                 break;
362                         blk += radix;
363                 }
364                 if (flags & SWIF_DUMP_TREE) {
365                         printf("%*.*s}\n", TABME);
366                 }
367         }
368         return(0);
369 }
370
371 static void
372 getswapinfo_radix(kvm_t *kd, struct kvm_swap *swap_ary, int swap_max, int flags)
373 {
374         struct blist *swapblist = NULL;
375         struct blist blcopy = { 0 };
376
377         KGET(NL_SWAPBLIST, swapblist);
378
379         if (swapblist == NULL) {
380                 if (flags & SWIF_DUMP_TREE)
381                         printf("radix tree: NULL - no swap in system\n");
382                 return;
383         }
384
385         KGET2(swapblist, &blcopy, sizeof(blcopy), "*swapblist");
386
387         if (flags & SWIF_DUMP_TREE) {
388                 printf("radix tree: %d/%d/%d blocks, %dK wired\n",
389                         blcopy.bl_free,
390                         blcopy.bl_blocks,
391                         blcopy.bl_radix,
392                         (int)((blcopy.bl_rootblks * sizeof(blmeta_t) + 1023)/
393                             1024)
394                 );
395         }
396         scanradix(
397             blcopy.bl_root, 
398             0, 
399             blcopy.bl_radix, 
400             blcopy.bl_skip, 
401             blcopy.bl_rootblks, 
402             kd,
403             dmmax,
404             nswdev, 
405             swap_ary,
406             swap_max,
407             0,
408             flags
409         );
410 }