Bug Summary

File:kern/subr_extent.c
Warning:line 742, column 6
Value stored to 'newend' is never read

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name subr_extent.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -ffreestanding -mcmodel=kernel -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -target-feature -sse2 -target-feature -sse -target-feature -3dnow -target-feature -mmx -target-feature +save-args -disable-red-zone -no-implicit-float -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -nostdsysteminc -nobuiltininc -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/sys -I /usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -I /usr/src/sys/arch -I /usr/src/sys/dev/pci/drm/include -I /usr/src/sys/dev/pci/drm/include/uapi -I /usr/src/sys/dev/pci/drm/amd/include/asic_reg -I /usr/src/sys/dev/pci/drm/amd/include -I /usr/src/sys/dev/pci/drm/amd/amdgpu -I /usr/src/sys/dev/pci/drm/amd/display -I /usr/src/sys/dev/pci/drm/amd/display/include -I /usr/src/sys/dev/pci/drm/amd/display/dc -I /usr/src/sys/dev/pci/drm/amd/display/amdgpu_dm -I /usr/src/sys/dev/pci/drm/amd/pm/inc -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu11 -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu12 -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/hwmgr -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/smumgr -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc/hw -I /usr/src/sys/dev/pci/drm/amd/display/dc/clk_mgr -I /usr/src/sys/dev/pci/drm/amd/display/modules/inc -I /usr/src/sys/dev/pci/drm/amd/display/modules/hdcp -I /usr/src/sys/dev/pci/drm/amd/display/dmub/inc -I /usr/src/sys/dev/pci/drm/i915 -D DDB -D DIAGNOSTIC -D KTRACE -D ACCOUNTING -D KMEMSTATS -D PTRACE -D POOL_DEBUG -D CRYPTO -D SYSVMSG -D SYSVSEM -D SYSVSHM -D UVM_SWAP_ENCRYPT -D FFS -D FFS2 -D FFS_SOFTUPDATES -D UFS_DIRHASH -D QUOTA -D EXT2FS -D MFS -D NFSCLIENT -D NFSSERVER -D CD9660 -D UDF -D MSDOSFS -D FIFO -D FUSE -D SOCKET_SPLICE -D TCP_ECN -D TCP_SIGNATURE -D INET6 -D IPSEC -D PPP_BSDCOMP -D PPP_DEFLATE -D PIPEX -D MROUTING -D MPLS -D BOOT_CONFIG -D USER_PCICONF -D APERTURE -D MTRR -D NTFS -D HIBERNATE -D PCIVERBOSE -D USBVERBOSE -D WSDISPLAY_COMPAT_USL -D WSDISPLAY_COMPAT_RAWKBD -D WSDISPLAY_DEFAULTSCREENS=6 -D X86EMU -D ONEWIREVERBOSE -D MULTIPROCESSOR -D MAXUSERS=80 -D _KERNEL -D CONFIG_DRM_AMD_DC_DCN3_0 -O2 -Wno-pointer-sign -Wno-address-of-packed-member -Wno-constant-conversion -Wno-unused-but-set-variable -Wno-gnu-folding-constant -fdebug-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -o /usr/obj/sys/arch/amd64/compile/GENERIC.MP/scan-build/2022-01-12-131800-47421-1 -x c /usr/src/sys/kern/subr_extent.c
1/* $OpenBSD: subr_extent.c,v 1.63 2020/01/11 14:30:24 mpi Exp $ */
2/* $NetBSD: subr_extent.c,v 1.7 1996/11/21 18:46:34 cgd Exp $ */
3
4/*-
5 * Copyright (c) 1996, 1998 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Jason R. Thorpe and Matthias Drochner.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33/*
34 * General purpose extent manager.
35 */
36
37#ifdef _KERNEL1
38#include <sys/param.h>
39#include <sys/extent.h>
40#include <sys/malloc.h>
41#include <sys/systm.h>
42#include <sys/queue.h>
43#include <sys/pool.h>
44#include <ddb/db_output.h>
45#else
46/*
47 * user-land definitions, so it can fit into a testing harness.
48 */
49#include <sys/param.h>
50#include <sys/extent.h>
51#include <sys/queue.h>
52#include <errno.h>
53#include <err.h>
54#include <stdlib.h>
55#include <stdio.h>
56#include <string.h>
57
58#define malloc(s, t, flags) malloc(s)
59#define free(p, t, s) free(p)
60
61#define tsleep_nsec(c, p, s, t) (EWOULDBLOCK35)
62#define wakeup(chan) ((void)0)
63
64struct pool {
65 size_t pr_size;
66};
67
68#define pool_init(a, b, c, d, e, f, g) do { (a)->pr_size = (b); } while (0)
69#define pool_get(pp, flags) malloc((pp)->pr_size, 0, 0)
70#define pool_put(pp, rp) free((rp), 0, 0)
71
72#define panic(...) do { warnx(__VA_ARGS__); abort(); } while (0)
73#endif
74
75#if defined(DIAGNOSTIC1) || defined(DDB1)
76void extent_print1(struct extent *, int (*)(const char *, ...)
77 __attribute__((__format__(__kprintf__,1,2))));
78#endif
79
80static void extent_insert_and_optimize(struct extent *, u_long, u_long,
81 struct extent_region *, struct extent_region *);
82static struct extent_region *extent_alloc_region_descriptor(struct extent *, int);
83static void extent_free_region_descriptor(struct extent *,
84 struct extent_region *);
85int extent_do_alloc(struct extent *, u_long, u_long, u_long, u_long,
86 u_long, u_long, int, struct extent_region *, u_long *);
87
88/*
89 * Shortcut to align to an arbitrary power-of-two boundary.
90 */
91static __inline__ u_long
92extent_align(u_long start, u_long align, u_long skew)
93{
94 return ((((start - skew) + (align - 1)) & (-align)) + skew);
95}
96
97
98#if defined(DIAGNOSTIC1) || defined(DDB1)
99/*
100 * Register the extent on a doubly linked list.
101 * Should work, no?
102 */
103static LIST_HEAD(listhead, extent)struct listhead { struct extent *lh_first; } ext_list;
104static void extent_register(struct extent *);
105
106static void
107extent_register(struct extent *ex)
108{
109#ifdef DIAGNOSTIC1
110 struct extent *ep;
111#endif
112 static int initialized;
113
114 if (!initialized){
115 LIST_INIT(&ext_list)do { ((&ext_list)->lh_first) = ((void *)0); } while (0
)
;
116 initialized = 1;
117 }
118
119#ifdef DIAGNOSTIC1
120 LIST_FOREACH(ep, &ext_list, ex_link)for((ep) = ((&ext_list)->lh_first); (ep)!= ((void *)0)
; (ep) = ((ep)->ex_link.le_next))
{
121 if (ep == ex)
122 panic("%s: already registered", __func__);
123 }
124#endif
125
126 /* Insert into list */
127 LIST_INSERT_HEAD(&ext_list, ex, ex_link)do { if (((ex)->ex_link.le_next = (&ext_list)->lh_first
) != ((void *)0)) (&ext_list)->lh_first->ex_link.le_prev
= &(ex)->ex_link.le_next; (&ext_list)->lh_first
= (ex); (ex)->ex_link.le_prev = &(&ext_list)->
lh_first; } while (0)
;
128}
129#endif /* DIAGNOSTIC || DDB */
130
131struct pool ex_region_pl;
132
133static void
134extent_pool_init(void)
135{
136 static int inited;
137
138 if (!inited) {
139 pool_init(&ex_region_pl, sizeof(struct extent_region), 0,
140 IPL_VM0xa, 0, "extentpl", NULL((void *)0));
141 inited = 1;
142 }
143}
144
145#ifdef DDB1
146/*
147 * Print out all extents registered. This is used in
148 * DDB show extents
149 */
150void
151extent_print_all(void)
152{
153 struct extent *ep;
154
155 LIST_FOREACH(ep, &ext_list, ex_link)for((ep) = ((&ext_list)->lh_first); (ep)!= ((void *)0)
; (ep) = ((ep)->ex_link.le_next))
{
156 extent_print1(ep, db_printf);
157 }
158}
159#endif
160
161/*
162 * Allocate and initialize an extent map.
163 */
164struct extent *
165extent_create(char *name, u_long start, u_long end, int mtype, caddr_t storage,
166 size_t storagesize, int flags)
167{
168 struct extent *ex;
169 caddr_t cp = storage;
170 size_t sz = storagesize;
171 struct extent_region *rp;
172 int fixed_extent = (storage != NULL((void *)0));
173
174#ifdef DIAGNOSTIC1
175 /* Check arguments. */
176 if (name == NULL((void *)0))
177 panic("%s: name == NULL", __func__);
178 if (end < start) {
179 printf("%s: extent `%s', start 0x%lx, end 0x%lx\n",
180 __func__, name, start, end);
181 panic("%s: end < start", __func__);
182 }
183 if (fixed_extent && (storagesize < sizeof(struct extent_fixed)))
184 panic("%s: fixed extent, bad storagesize 0x%lx",
185 __func__, (u_long)storagesize);
186 if (fixed_extent == 0 && (storagesize != 0 || storage != NULL((void *)0)))
187 panic("%s: storage provided for non-fixed", __func__);
188#endif
189
190 extent_pool_init();
191
192 /* Allocate extent descriptor. */
193 if (fixed_extent) {
194 struct extent_fixed *fex;
195
196 memset(storage, 0, storagesize)__builtin_memset((storage), (0), (storagesize));
197
198 /*
199 * Align all descriptors on "long" boundaries.
200 */
201 fex = (struct extent_fixed *)cp;
202 ex = (struct extent *)fex;
203 cp += ALIGN(sizeof(struct extent_fixed))(((unsigned long)(sizeof(struct extent_fixed)) + (sizeof(long
) - 1)) &~(sizeof(long) - 1))
;
204 sz -= ALIGN(sizeof(struct extent_fixed))(((unsigned long)(sizeof(struct extent_fixed)) + (sizeof(long
) - 1)) &~(sizeof(long) - 1))
;
205 fex->fex_storage = storage;
206 fex->fex_storagesize = storagesize;
207
208 /*
209 * In a fixed extent, we have to pre-allocate region
210 * descriptors and place them in the extent's freelist.
211 */
212 LIST_INIT(&fex->fex_freelist)do { ((&fex->fex_freelist)->lh_first) = ((void *)0)
; } while (0)
;
213 while (sz >= ALIGN(sizeof(struct extent_region))(((unsigned long)(sizeof(struct extent_region)) + (sizeof(long
) - 1)) &~(sizeof(long) - 1))
) {
214 rp = (struct extent_region *)cp;
215 cp += ALIGN(sizeof(struct extent_region))(((unsigned long)(sizeof(struct extent_region)) + (sizeof(long
) - 1)) &~(sizeof(long) - 1))
;
216 sz -= ALIGN(sizeof(struct extent_region))(((unsigned long)(sizeof(struct extent_region)) + (sizeof(long
) - 1)) &~(sizeof(long) - 1))
;
217 LIST_INSERT_HEAD(&fex->fex_freelist, rp, er_link)do { if (((rp)->er_link.le_next = (&fex->fex_freelist
)->lh_first) != ((void *)0)) (&fex->fex_freelist)->
lh_first->er_link.le_prev = &(rp)->er_link.le_next;
(&fex->fex_freelist)->lh_first = (rp); (rp)->er_link
.le_prev = &(&fex->fex_freelist)->lh_first; } while
(0)
;
218 }
219 } else {
220 ex = (struct extent *)malloc(sizeof(struct extent),
221 mtype, (flags & EX_WAITOK0x0001) ? M_WAITOK0x0001 : M_NOWAIT0x0002);
222 if (ex == NULL((void *)0))
223 return (NULL((void *)0));
224 }
225
226 /* Fill in the extent descriptor and return it to the caller. */
227 LIST_INIT(&ex->ex_regions)do { ((&ex->ex_regions)->lh_first) = ((void *)0); }
while (0)
;
228 ex->ex_name = name;
229 ex->ex_start = start;
230 ex->ex_end = end;
231 ex->ex_mtype = mtype;
232 ex->ex_flags = 0;
233 if (fixed_extent)
234 ex->ex_flags |= EXF_FIXED0x01;
235 if (flags & EX_NOCOALESCE0x0008)
236 ex->ex_flags |= EXF_NOCOALESCE0x02;
237
238 if (flags & EX_FILLED0x0100) {
239 rp = extent_alloc_region_descriptor(ex, flags);
240 if (rp == NULL((void *)0)) {
241 if (!fixed_extent)
242 free(ex, mtype, sizeof(struct extent));
243 return (NULL((void *)0));
244 }
245 rp->er_start = start;
246 rp->er_end = end;
247 LIST_INSERT_HEAD(&ex->ex_regions, rp, er_link)do { if (((rp)->er_link.le_next = (&ex->ex_regions)
->lh_first) != ((void *)0)) (&ex->ex_regions)->lh_first
->er_link.le_prev = &(rp)->er_link.le_next; (&ex
->ex_regions)->lh_first = (rp); (rp)->er_link.le_prev
= &(&ex->ex_regions)->lh_first; } while (0)
;
248 }
249
250#if defined(DIAGNOSTIC1) || defined(DDB1)
251 extent_register(ex);
252#endif
253 return (ex);
254}
255
256/*
257 * Destroy an extent map.
258 */
259void
260extent_destroy(struct extent *ex)
261{
262 struct extent_region *rp, *orp;
263
264#ifdef DIAGNOSTIC1
265 /* Check arguments. */
266 if (ex == NULL((void *)0))
267 panic("%s: NULL extent", __func__);
268#endif
269
270 /* Free all region descriptors in extent. */
271 for (rp = LIST_FIRST(&ex->ex_regions)((&ex->ex_regions)->lh_first); rp != NULL((void *)0); ) {
272 orp = rp;
273 rp = LIST_NEXT(rp, er_link)((rp)->er_link.le_next);
274 LIST_REMOVE(orp, er_link)do { if ((orp)->er_link.le_next != ((void *)0)) (orp)->
er_link.le_next->er_link.le_prev = (orp)->er_link.le_prev
; *(orp)->er_link.le_prev = (orp)->er_link.le_next; ((orp
)->er_link.le_prev) = ((void *)-1); ((orp)->er_link.le_next
) = ((void *)-1); } while (0)
;
275 extent_free_region_descriptor(ex, orp);
276 }
277
278#if defined(DIAGNOSTIC1) || defined(DDB1)
279 /* Remove from the list of all extents. */
280 LIST_REMOVE(ex, ex_link)do { if ((ex)->ex_link.le_next != ((void *)0)) (ex)->ex_link
.le_next->ex_link.le_prev = (ex)->ex_link.le_prev; *(ex
)->ex_link.le_prev = (ex)->ex_link.le_next; ((ex)->ex_link
.le_prev) = ((void *)-1); ((ex)->ex_link.le_next) = ((void
*)-1); } while (0)
;
281#endif
282
283 /* If we're not a fixed extent, free the extent descriptor itself. */
284 if ((ex->ex_flags & EXF_FIXED0x01) == 0)
285 free(ex, ex->ex_mtype, sizeof(*ex));
286}
287
288/*
289 * Insert a region descriptor into the sorted region list after the
290 * entry "after" or at the head of the list (if "after" is NULL).
291 * The region descriptor we insert is passed in "rp". We must
292 * allocate the region descriptor before calling this function!
293 * If we don't need the region descriptor, it will be freed here.
294 */
295static void
296extent_insert_and_optimize(struct extent *ex, u_long start, u_long size,
297 struct extent_region *after, struct extent_region *rp)
298{
299 struct extent_region *nextr;
300 int appended = 0;
301
302 if (after == NULL((void *)0)) {
303 /*
304 * We're the first in the region list. If there's
305 * a region after us, attempt to coalesce to save
306 * descriptor overhead.
307 */
308 if (((ex->ex_flags & EXF_NOCOALESCE0x02) == 0) &&
309 !LIST_EMPTY(&ex->ex_regions)(((&ex->ex_regions)->lh_first) == ((void *)0)) &&
310 ((start + size) == LIST_FIRST(&ex->ex_regions)((&ex->ex_regions)->lh_first)->er_start)) {
311 /*
312 * We can coalesce. Prepend us to the first region.
313 */
314 LIST_FIRST(&ex->ex_regions)((&ex->ex_regions)->lh_first)->er_start = start;
315 extent_free_region_descriptor(ex, rp);
316 return;
317 }
318
319 /*
320 * Can't coalesce. Fill in the region descriptor
321 * in, and insert us at the head of the region list.
322 */
323 rp->er_start = start;
324 rp->er_end = start + (size - 1);
325 LIST_INSERT_HEAD(&ex->ex_regions, rp, er_link)do { if (((rp)->er_link.le_next = (&ex->ex_regions)
->lh_first) != ((void *)0)) (&ex->ex_regions)->lh_first
->er_link.le_prev = &(rp)->er_link.le_next; (&ex
->ex_regions)->lh_first = (rp); (rp)->er_link.le_prev
= &(&ex->ex_regions)->lh_first; } while (0)
;
326 return;
327 }
328
329 /*
330 * If EXF_NOCOALESCE is set, coalescing is disallowed.
331 */
332 if (ex->ex_flags & EXF_NOCOALESCE0x02)
333 goto cant_coalesce;
334
335 /*
336 * Attempt to coalesce with the region before us.
337 */
338 if ((after->er_end + 1) == start) {
339 /*
340 * We can coalesce. Append ourselves and make
341 * note of it.
342 */
343 after->er_end = start + (size - 1);
344 appended = 1;
345 }
346
347 /*
348 * Attempt to coalesce with the region after us.
349 */
350 if (LIST_NEXT(after, er_link)((after)->er_link.le_next) != NULL((void *)0) &&
351 ((start + size) == LIST_NEXT(after, er_link)((after)->er_link.le_next)->er_start)) {
352 /*
353 * We can coalesce. Note that if we appended ourselves
354 * to the previous region, we exactly fit the gap, and
355 * can free the "next" region descriptor.
356 */
357 if (appended) {
358 /*
359 * Yup, we can free it up.
360 */
361 after->er_end = LIST_NEXT(after, er_link)((after)->er_link.le_next)->er_end;
362 nextr = LIST_NEXT(after, er_link)((after)->er_link.le_next);
363 LIST_REMOVE(nextr, er_link)do { if ((nextr)->er_link.le_next != ((void *)0)) (nextr)->
er_link.le_next->er_link.le_prev = (nextr)->er_link.le_prev
; *(nextr)->er_link.le_prev = (nextr)->er_link.le_next;
((nextr)->er_link.le_prev) = ((void *)-1); ((nextr)->er_link
.le_next) = ((void *)-1); } while (0)
;
364 extent_free_region_descriptor(ex, nextr);
365 } else {
366 /*
367 * Nope, just prepend us to the next region.
368 */
369 LIST_NEXT(after, er_link)((after)->er_link.le_next)->er_start = start;
370 }
371
372 extent_free_region_descriptor(ex, rp);
373 return;
374 }
375
376 /*
377 * We weren't able to coalesce with the next region, but
378 * we don't need to allocate a region descriptor if we
379 * appended ourselves to the previous region.
380 */
381 if (appended) {
382 extent_free_region_descriptor(ex, rp);
383 return;
384 }
385
386 cant_coalesce:
387
388 /*
389 * Fill in the region descriptor and insert ourselves
390 * into the region list.
391 */
392 rp->er_start = start;
393 rp->er_end = start + (size - 1);
394 LIST_INSERT_AFTER(after, rp, er_link)do { if (((rp)->er_link.le_next = (after)->er_link.le_next
) != ((void *)0)) (after)->er_link.le_next->er_link.le_prev
= &(rp)->er_link.le_next; (after)->er_link.le_next
= (rp); (rp)->er_link.le_prev = &(after)->er_link.
le_next; } while (0)
;
395}
396
397/*
398 * Allocate a specific region in an extent map.
399 */
400int
401extent_alloc_region(struct extent *ex, u_long start, u_long size, int flags)
402{
403 struct extent_region *rp, *last, *myrp;
404 u_long end = start + (size - 1);
405 int error;
406
407#ifdef DIAGNOSTIC1
408 /* Check arguments. */
409 if (ex == NULL((void *)0))
410 panic("%s: NULL extent", __func__);
411 if (size < 1) {
412 printf("%s: extent `%s', size 0x%lx\n",
413 __func__, ex->ex_name, size);
414 panic("%s: bad size", __func__);
415 }
416 if (end < start) {
417 printf("%s: extent `%s', start 0x%lx, size 0x%lx\n",
418 __func__, ex->ex_name, start, size);
419 panic("%s: overflow", __func__);
420 }
421 if ((flags & EX_CONFLICTOK0x0080) && (flags & EX_WAITSPACE0x0020))
422 panic("%s: EX_CONFLICTOK and EX_WAITSPACE "
423 "are mutually exclusive", __func__);
424#endif
425
426 /*
427 * Make sure the requested region lies within the
428 * extent.
429 */
430 if ((start < ex->ex_start) || (end > ex->ex_end)) {
431#ifdef DIAGNOSTIC1
432 printf("%s: extent `%s' (0x%lx - 0x%lx)\n",
433 __func__, ex->ex_name, ex->ex_start, ex->ex_end);
434 printf("%s: start 0x%lx, end 0x%lx\n",
435 __func__, start, end);
436 panic("%s: region lies outside extent", __func__);
437#else
438 return (EINVAL22);
439#endif
440 }
441
442 /*
443 * Allocate the region descriptor. It will be freed later
444 * if we can coalesce with another region.
445 */
446 myrp = extent_alloc_region_descriptor(ex, flags);
447 if (myrp == NULL((void *)0)) {
448#ifdef DIAGNOSTIC1
449 printf(
450 "%s: can't allocate region descriptor\n", __func__);
451#endif
452 return (ENOMEM12);
453 }
454
455 alloc_start:
456 /*
457 * Attempt to place ourselves in the desired area of the
458 * extent. We save ourselves some work by keeping the list sorted.
459 * In other words, if the start of the current region is greater
460 * than the end of our region, we don't have to search any further.
461 */
462
463 /*
464 * Keep a pointer to the last region we looked at so
465 * that we don't have to traverse the list again when
466 * we insert ourselves. If "last" is NULL when we
467 * finally insert ourselves, we go at the head of the
468 * list. See extent_insert_and_optimize() for details.
469 */
470 last = NULL((void *)0);
471
472 LIST_FOREACH(rp, &ex->ex_regions, er_link)for((rp) = ((&ex->ex_regions)->lh_first); (rp)!= ((
void *)0); (rp) = ((rp)->er_link.le_next))
{
473 if (rp->er_start > end) {
474 /*
475 * We lie before this region and don't
476 * conflict.
477 */
478 break;
479 }
480
481 /*
482 * The current region begins before we end.
483 * Check for a conflict.
484 */
485 if (rp->er_end >= start) {
486 /*
487 * We conflict. If we can (and want to) wait,
488 * do so.
489 */
490 if (flags & EX_WAITSPACE0x0020) {
491 ex->ex_flags |= EXF_WANTED0x04;
492 error = tsleep_nsec(ex,
493 PRIBIO16 | ((flags & EX_CATCH0x0004) ? PCATCH0x100 : 0),
494 "extnt", INFSLP0xffffffffffffffffULL);
495 if (error)
496 return (error);
497 goto alloc_start;
498 }
499
500 /*
501 * If we tolerate conflicts adjust things such
502 * that all space in the requested region is
503 * allocated.
504 */
505 if (flags & EX_CONFLICTOK0x0080) {
506 /*
507 * There are four possibilities:
508 *
509 * 1. The current region overlaps with
510 * the start of the requested region.
511 * Adjust the requested region to
512 * start at the end of the current
513 * region and try again.
514 *
515 * 2. The current region falls
516 * completely within the requested
517 * region. Free the current region
518 * and try again.
519 *
520 * 3. The current region overlaps with
521 * the end of the requested region.
522 * Adjust the requested region to
523 * end at the start of the current
524 * region and try again.
525 *
526 * 4. The requested region falls
527 * completely within the current
528 * region. We're done.
529 */
530 if (rp->er_start <= start) {
531 if (rp->er_end < ex->ex_end) {
532 start = rp->er_end + 1;
533 size = end - start + 1;
534 goto alloc_start;
535 }
536 } else if (rp->er_end < end) {
537 LIST_REMOVE(rp, er_link)do { if ((rp)->er_link.le_next != ((void *)0)) (rp)->er_link
.le_next->er_link.le_prev = (rp)->er_link.le_prev; *(rp
)->er_link.le_prev = (rp)->er_link.le_next; ((rp)->er_link
.le_prev) = ((void *)-1); ((rp)->er_link.le_next) = ((void
*)-1); } while (0)
;
538 extent_free_region_descriptor(ex, rp);
539 goto alloc_start;
540 } else if (rp->er_start < end) {
541 if (rp->er_start > ex->ex_start) {
542 end = rp->er_start - 1;
543 size = end - start + 1;
544 goto alloc_start;
545 }
546 }
547 return (0);
548 }
549
550 extent_free_region_descriptor(ex, myrp);
551 return (EAGAIN35);
552 }
553 /*
554 * We don't conflict, but this region lies before
555 * us. Keep a pointer to this region, and keep
556 * trying.
557 */
558 last = rp;
559 }
560
561 /*
562 * We don't conflict with any regions. "last" points
563 * to the region we fall after, or is NULL if we belong
564 * at the beginning of the region list. Insert ourselves.
565 */
566 extent_insert_and_optimize(ex, start, size, last, myrp);
567 return (0);
568}
569
570/*
571 * Macro to check (x + y) <= z. This check is designed to fail
572 * if an overflow occurs.
573 */
574#define LE_OV(x, y, z)((((x) + (y)) >= (x)) && (((x) + (y)) <= (z))) ((((x) + (y)) >= (x)) && (((x) + (y)) <= (z)))
575
576/*
577 * Allocate a region in an extent map subregion.
578 *
579 * If EX_FAST is specified, we return the first fit in the map.
580 * Otherwise, we try to minimize fragmentation by finding the
581 * smallest gap that will hold the request.
582 *
583 * The allocated region is aligned to "alignment", which must be
584 * a power of 2.
585 */
586int
587extent_do_alloc(struct extent *ex, u_long substart, u_long subend,
588 u_long size, u_long alignment, u_long skew, u_long boundary, int flags,
589 struct extent_region *myrp, u_long *result)
590{
591 struct extent_region *rp, *last, *bestlast;
592 u_long newstart, newend, exend, beststart, bestovh, ovh;
593 u_long dontcross;
594 int error;
595
596#ifdef DIAGNOSTIC1
597 /* Check arguments. */
598 if (ex == NULL((void *)0))
599 panic("%s: NULL extent", __func__);
600 if (myrp == NULL((void *)0))
601 panic("%s: NULL region descriptor", __func__);
602 if (result == NULL((void *)0))
603 panic("%s: NULL result pointer", __func__);
604 if ((substart < ex->ex_start) || (substart > ex->ex_end) ||
605 (subend > ex->ex_end) || (subend < ex->ex_start)) {
606 printf("%s: extent `%s', ex_start 0x%lx, ex_end 0x%lx\n",
607 __func__, ex->ex_name, ex->ex_start, ex->ex_end);
608 printf("%s: substart 0x%lx, subend 0x%lx\n",
609 __func__, substart, subend);
610 panic("%s: bad subregion", __func__);
611 }
612 if ((size < 1) || ((size - 1) > (subend - substart))) {
613 printf("%s: extent `%s', size 0x%lx\n",
614 __func__, ex->ex_name, size);
615 panic("%s: bad size", __func__);
616 }
617 if (alignment == 0)
618 panic("%s: bad alignment", __func__);
619 if (boundary && (boundary < size)) {
620 printf("%s: extent `%s', size 0x%lx, boundary 0x%lx\n",
621 __func__, ex->ex_name, size, boundary);
622 panic("%s: bad boundary", __func__);
623 }
624#endif
625
626 alloc_start:
627 /*
628 * Keep a pointer to the last region we looked at so
629 * that we don't have to traverse the list again when
630 * we insert ourselves. If "last" is NULL when we
631 * finally insert ourselves, we go at the head of the
632 * list. See extent_insert_and_optimize() for details.
633 */
634 last = NULL((void *)0);
635
636 /*
637 * Keep track of size and location of the smallest
638 * chunk we fit in.
639 *
640 * Since the extent can be as large as the numeric range
641 * of the CPU (0 - 0xffffffff for 32-bit systems), the
642 * best overhead value can be the maximum unsigned integer.
643 * Thus, we initialize "bestovh" to 0, since we insert ourselves
644 * into the region list immediately on an exact match (which
645 * is the only case where "bestovh" would be set to 0).
646 */
647 bestovh = 0;
648 beststart = 0;
649 bestlast = NULL((void *)0);
650
651 /*
652 * Keep track of end of free region. This is either the end of extent
653 * or the start of a region past the subend.
654 */
655 exend = ex->ex_end;
656
657 /*
658 * For N allocated regions, we must make (N + 1)
659 * checks for unallocated space. The first chunk we
660 * check is the area from the beginning of the subregion
661 * to the first allocated region after that point.
662 */
663 newstart = extent_align(substart, alignment, skew);
664 if (newstart < ex->ex_start) {
665#ifdef DIAGNOSTIC1
666 printf("%s: extent `%s' (0x%lx - 0x%lx), alignment 0x%lx\n",
667 __func__, ex->ex_name, ex->ex_start, ex->ex_end,
668 alignment);
669 panic("%s: overflow after alignment", __func__);
670#else
671 extent_free_region_descriptor(ex, myrp);
672 return (EINVAL22);
673#endif
674 }
675
676 /*
677 * Find the first allocated region that begins on or after
678 * the subregion start, advancing the "last" pointer along
679 * the way.
680 */
681 LIST_FOREACH(rp, &ex->ex_regions, er_link)for((rp) = ((&ex->ex_regions)->lh_first); (rp)!= ((
void *)0); (rp) = ((rp)->er_link.le_next))
{
682 if (rp->er_start >= newstart)
683 break;
684 last = rp;
685 }
686
687 /*
688 * Relocate the start of our candidate region to the end of
689 * the last allocated region (if there was one overlapping
690 * our subrange).
691 */
692 if (last != NULL((void *)0) && last->er_end >= newstart)
693 newstart = extent_align((last->er_end + 1), alignment, skew);
694
695 for (; rp != NULL((void *)0); rp = LIST_NEXT(rp, er_link)((rp)->er_link.le_next)) {
696 /*
697 * If the region pasts the subend, bail out and see
698 * if we fit against the subend.
699 */
700 if (rp->er_start > subend) {
701 exend = rp->er_start;
702 break;
703 }
704
705 /*
706 * Check the chunk before "rp". Note that our
707 * comparison is safe from overflow conditions.
708 */
709 if (LE_OV(newstart, size, rp->er_start)((((newstart) + (size)) >= (newstart)) && (((newstart
) + (size)) <= (rp->er_start)))
) {
710 /*
711 * Do a boundary check, if necessary. Note
712 * that a region may *begin* on the boundary,
713 * but it must end before the boundary.
714 */
715 if (boundary) {
716 newend = newstart + (size - 1);
717
718 /*
719 * Calculate the next boundary after the start
720 * of this region.
721 */
722 dontcross = extent_align(newstart+1, boundary,
723 (flags & EX_BOUNDZERO0x0040) ? 0 : ex->ex_start)
724 - 1;
725
726#if 0
727 printf("newstart=%lx newend=%lx ex_start=%lx ex_end=%lx boundary=%lx dontcross=%lx\n",
728 newstart, newend, ex->ex_start, ex->ex_end,
729 boundary, dontcross);
730#endif
731
732 /* Check for overflow */
733 if (dontcross < ex->ex_start)
734 dontcross = ex->ex_end;
735 else if (newend > dontcross) {
736 /*
737 * Candidate region crosses boundary.
738 * Throw away the leading part and see
739 * if we still fit.
740 */
741 newstart = dontcross + 1;
742 newend = newstart + (size - 1);
Value stored to 'newend' is never read
743 dontcross += boundary;
744 if (!LE_OV(newstart, size, rp->er_start)((((newstart) + (size)) >= (newstart)) && (((newstart
) + (size)) <= (rp->er_start)))
)
745 goto skip;
746 }
747
748 /*
749 * If we run past the end of
750 * the extent or the boundary
751 * overflows, then the request
752 * can't fit.
753 */
754 if (newstart + size - 1 > ex->ex_end ||
755 dontcross < newstart)
756 goto fail;
757 }
758
759 /*
760 * We would fit into this space. Calculate
761 * the overhead (wasted space). If we exactly
762 * fit, or we're taking the first fit, insert
763 * ourselves into the region list.
764 */
765 ovh = rp->er_start - newstart - size;
766 if ((flags & EX_FAST0x0002) || (ovh == 0))
767 goto found;
768
769 /*
770 * Don't exactly fit, but check to see
771 * if we're better than any current choice.
772 */
773 if ((bestovh == 0) || (ovh < bestovh)) {
774 bestovh = ovh;
775 beststart = newstart;
776 bestlast = last;
777 }
778 }
779
780skip:
781 /*
782 * Skip past the current region and check again.
783 */
784 newstart = extent_align((rp->er_end + 1), alignment, skew);
785 if (newstart < rp->er_end) {
786 /*
787 * Overflow condition. Don't error out, since
788 * we might have a chunk of space that we can
789 * use.
790 */
791 goto fail;
792 }
793
794 last = rp;
795 }
796
797 /*
798 * The final check is from the current starting point to the
799 * end of the subregion. If there were no allocated regions,
800 * "newstart" is set to the beginning of the subregion, or
801 * just past the end of the last allocated region, adjusted
802 * for alignment in either case.
803 */
804 if (LE_OV(newstart, (size - 1), subend)((((newstart) + ((size - 1))) >= (newstart)) && ((
(newstart) + ((size - 1))) <= (subend)))
) {
805 /*
806 * Do a boundary check, if necessary. Note
807 * that a region may *begin* on the boundary,
808 * but it must end before the boundary.
809 */
810 if (boundary) {
811 newend = newstart + (size - 1);
812
813 /*
814 * Calculate the next boundary after the start
815 * of this region.
816 */
817 dontcross = extent_align(newstart+1, boundary,
818 (flags & EX_BOUNDZERO0x0040) ? 0 : ex->ex_start)
819 - 1;
820
821#if 0
822 printf("newstart=%lx newend=%lx ex_start=%lx ex_end=%lx boundary=%lx dontcross=%lx\n",
823 newstart, newend, ex->ex_start, ex->ex_end,
824 boundary, dontcross);
825#endif
826
827 /* Check for overflow */
828 if (dontcross < ex->ex_start)
829 dontcross = ex->ex_end;
830 else if (newend > dontcross) {
831 /*
832 * Candidate region crosses boundary.
833 * Throw away the leading part and see
834 * if we still fit.
835 */
836 newstart = dontcross + 1;
837 newend = newstart + (size - 1);
838 dontcross += boundary;
839 if (!LE_OV(newstart, (size - 1), subend)((((newstart) + ((size - 1))) >= (newstart)) && ((
(newstart) + ((size - 1))) <= (subend)))
)
840 goto fail;
841 }
842
843 /*
844 * If we run past the end of
845 * the extent or the boundary
846 * overflows, then the request
847 * can't fit.
848 */
849 if (newstart + size - 1 > ex->ex_end ||
850 dontcross < newstart)
851 goto fail;
852 }
853
854 /*
855 * We would fit into this space. Calculate
856 * the overhead (wasted space). If we exactly
857 * fit, or we're taking the first fit, insert
858 * ourselves into the region list.
859 */
860 ovh = exend - newstart - (size - 1);
861 if ((flags & EX_FAST0x0002) || (ovh == 0))
862 goto found;
863
864 /*
865 * Don't exactly fit, but check to see
866 * if we're better than any current choice.
867 */
868 if ((bestovh == 0) || (ovh < bestovh)) {
869 bestovh = ovh;
870 beststart = newstart;
871 bestlast = last;
872 }
873 }
874
875 fail:
876 /*
877 * One of the following two conditions have
878 * occurred:
879 *
880 * There is no chunk large enough to hold the request.
881 *
882 * If EX_FAST was not specified, there is not an
883 * exact match for the request.
884 *
885 * Note that if we reach this point and EX_FAST is
886 * set, then we know there is no space in the extent for
887 * the request.
888 */
889 if (((flags & EX_FAST0x0002) == 0) && (bestovh != 0)) {
890 /*
891 * We have a match that's "good enough".
892 */
893 newstart = beststart;
894 last = bestlast;
895 goto found;
896 }
897
898 /*
899 * No space currently available. Wait for it to free up,
900 * if possible.
901 */
902 if (flags & EX_WAITSPACE0x0020) {
903 ex->ex_flags |= EXF_WANTED0x04;
904 error = tsleep_nsec(ex,
905 PRIBIO16 | ((flags & EX_CATCH0x0004) ? PCATCH0x100 : 0),
906 "extnt", INFSLP0xffffffffffffffffULL);
907 if (error)
908 return (error);
909 goto alloc_start;
910 }
911
912 extent_free_region_descriptor(ex, myrp);
913 return (EAGAIN35);
914
915 found:
916 /*
917 * Insert ourselves into the region list.
918 */
919 extent_insert_and_optimize(ex, newstart, size, last, myrp);
920 *result = newstart;
921 return (0);
922}
923
924int
925extent_alloc_subregion(struct extent *ex, u_long substart, u_long subend,
926 u_long size, u_long alignment, u_long skew, u_long boundary, int flags,
927 u_long *result)
928{
929 struct extent_region *rp;
930
931 /*
932 * Allocate the region descriptor. It will be freed later
933 * if we can coalesce with another region.
934 */
935 rp = extent_alloc_region_descriptor(ex, flags);
936 if (rp == NULL((void *)0)) {
937#ifdef DIAGNOSTIC1
938 printf("%s: can't allocate region descriptor\n", __func__);
939#endif
940 return (ENOMEM12);
941 }
942
943 return extent_do_alloc(ex, substart, subend, size, alignment, skew,
944 boundary, flags, rp, result);
945}
946
947int
948extent_alloc_subregion_with_descr(struct extent *ex, u_long substart,
949 u_long subend, u_long size, u_long alignment, u_long skew,
950 u_long boundary, int flags, struct extent_region *rp, u_long *result)
951{
952#ifdef DIAGNOSTIC1
953 if ((ex->ex_flags & EXF_NOCOALESCE0x02) == 0)
954 panic("%s: EX_NOCOALESCE not set", __func__);
955#endif
956
957 rp->er_flags = ER_DISCARD0x02;
958 return extent_do_alloc(ex, substart, subend, size, alignment, skew,
959 boundary, flags, rp, result);
960}
961
962int
963extent_free(struct extent *ex, u_long start, u_long size, int flags)
964{
965 struct extent_region *rp, *nrp = NULL((void *)0);
966 struct extent_region *tmp;
967 u_long end = start + (size - 1);
968 int exflags;
969 int error = 0;
970
971#ifdef DIAGNOSTIC1
972 /* Check arguments. */
973 if (ex == NULL((void *)0))
974 panic("%s: NULL extent", __func__);
975 if ((start < ex->ex_start) || (end > ex->ex_end)) {
976 extent_print(ex);
977 printf("%s: extent `%s', start 0x%lx, size 0x%lx\n",
978 __func__, ex->ex_name, start, size);
979 panic("%s: extent `%s', region not within extent",
980 __func__, ex->ex_name);
981 }
982 /* Check for an overflow. */
983 if (end < start) {
984 extent_print(ex);
985 printf("%s: extent `%s', start 0x%lx, size 0x%lx\n",
986 __func__, ex->ex_name, start, size);
987 panic("%s: overflow", __func__);
988 }
989#endif
990
991 /*
992 * If we're allowing coalescing, we must allocate a region
993 * descriptor now, since it might block.
994 *
995 * XXX Make a static, create-time flags word, so we don't
996 * XXX have to lock to read it!
997 */
998 exflags = ex->ex_flags;
999
1000 if ((exflags & EXF_NOCOALESCE0x02) == 0) {
1001 /* Allocate a region descriptor. */
1002 nrp = extent_alloc_region_descriptor(ex, flags);
1003 if (nrp == NULL((void *)0))
1004 return (ENOMEM12);
1005 }
1006
1007 /*
1008 * Find region and deallocate. Several possibilities:
1009 *
1010 * 1. (start == er_start) && (end == er_end):
1011 * Free descriptor.
1012 *
1013 * 2. (start == er_start) && (end < er_end):
1014 * Adjust er_start.
1015 *
1016 * 3. (start > er_start) && (end == er_end):
1017 * Adjust er_end.
1018 *
1019 * 4. (start > er_start) && (end < er_end):
1020 * Fragment region. Requires descriptor alloc.
1021 *
1022 * Cases 2, 3, and 4 require that the EXF_NOCOALESCE flag
1023 * is not set.
1024 *
1025 * If the EX_CONFLICTOK flag is set, partially overlapping
1026 * regions are allowed. This is handled in cases 1a, 2a and
1027 * 3a below.
1028 */
1029 LIST_FOREACH_SAFE(rp, &ex->ex_regions, er_link, tmp)for ((rp) = ((&ex->ex_regions)->lh_first); (rp) &&
((tmp) = ((rp)->er_link.le_next), 1); (rp) = (tmp))
{
1030 /*
1031 * Save ourselves some comparisons; does the current
1032 * region end before chunk to be freed begins? If so,
1033 * then we haven't found the appropriate region descriptor.
1034 */
1035 if (rp->er_end < start)
1036 continue;
1037
1038 /*
1039 * Save ourselves some traversal; does the current
1040 * region begin after the chunk to be freed ends? If so,
1041 * then we've already passed any possible region descriptors
1042 * that might have contained the chunk to be freed.
1043 */
1044 if (rp->er_start > end)
1045 break;
1046
1047 /* Case 1. */
1048 if ((start == rp->er_start) && (end == rp->er_end)) {
1049 LIST_REMOVE(rp, er_link)do { if ((rp)->er_link.le_next != ((void *)0)) (rp)->er_link
.le_next->er_link.le_prev = (rp)->er_link.le_prev; *(rp
)->er_link.le_prev = (rp)->er_link.le_next; ((rp)->er_link
.le_prev) = ((void *)-1); ((rp)->er_link.le_next) = ((void
*)-1); } while (0)
;
1050 extent_free_region_descriptor(ex, rp);
1051 goto done;
1052 }
1053
1054 /*
1055 * The following cases all require that EXF_NOCOALESCE
1056 * is not set.
1057 */
1058 if (ex->ex_flags & EXF_NOCOALESCE0x02)
1059 continue;
1060
1061 /* Case 2. */
1062 if ((start == rp->er_start) && (end < rp->er_end)) {
1063 rp->er_start = (end + 1);
1064 goto done;
1065 }
1066
1067 /* Case 3. */
1068 if ((start > rp->er_start) && (end == rp->er_end)) {
1069 rp->er_end = (start - 1);
1070 goto done;
1071 }
1072
1073 /* Case 4. */
1074 if ((start > rp->er_start) && (end < rp->er_end)) {
1075 /* Fill in new descriptor. */
1076 nrp->er_start = end + 1;
1077 nrp->er_end = rp->er_end;
1078
1079 /* Adjust current descriptor. */
1080 rp->er_end = start - 1;
1081
1082 /* Insert new descriptor after current. */
1083 LIST_INSERT_AFTER(rp, nrp, er_link)do { if (((nrp)->er_link.le_next = (rp)->er_link.le_next
) != ((void *)0)) (rp)->er_link.le_next->er_link.le_prev
= &(nrp)->er_link.le_next; (rp)->er_link.le_next =
(nrp); (nrp)->er_link.le_prev = &(rp)->er_link.le_next
; } while (0)
;
1084
1085 /* We used the new descriptor, so don't free it below */
1086 nrp = NULL((void *)0);
1087 goto done;
1088 }
1089
1090 if ((flags & EX_CONFLICTOK0x0080) == 0)
1091 continue;
1092
1093 /* Case 1a. */
1094 if ((start <= rp->er_start && end >= rp->er_end)) {
1095 LIST_REMOVE(rp, er_link)do { if ((rp)->er_link.le_next != ((void *)0)) (rp)->er_link
.le_next->er_link.le_prev = (rp)->er_link.le_prev; *(rp
)->er_link.le_prev = (rp)->er_link.le_next; ((rp)->er_link
.le_prev) = ((void *)-1); ((rp)->er_link.le_next) = ((void
*)-1); } while (0)
;
1096 extent_free_region_descriptor(ex, rp);
1097 continue;
1098 }
1099
1100 /* Case 2a. */
1101 if ((start <= rp->er_start) && (end >= rp->er_start))
1102 rp->er_start = (end + 1);
1103
1104 /* Case 3a. */
1105 if ((start <= rp->er_end) && (end >= rp->er_end))
1106 rp->er_end = (start - 1);
1107 }
1108
1109 if (flags & EX_CONFLICTOK0x0080)
1110 goto done;
1111
1112 /* Region not found, or request otherwise invalid. */
1113#if defined(DIAGNOSTIC1) || defined(DDB1)
1114 extent_print(ex);
1115#endif
1116 printf("%s: start 0x%lx, end 0x%lx\n", __func__, start, end);
1117 panic("%s: region not found", __func__);
1118
1119 done:
1120 if (nrp != NULL((void *)0))
1121 extent_free_region_descriptor(ex, nrp);
1122 if (ex->ex_flags & EXF_WANTED0x04) {
1123 ex->ex_flags &= ~EXF_WANTED0x04;
1124 wakeup(ex);
1125 }
1126 return (error);
1127}
1128
1129static struct extent_region *
1130extent_alloc_region_descriptor(struct extent *ex, int flags)
1131{
1132 struct extent_region *rp;
1133
1134 if (ex->ex_flags & EXF_FIXED0x01) {
1135 struct extent_fixed *fex = (struct extent_fixed *)ex;
1136
1137 while (LIST_EMPTY(&fex->fex_freelist)(((&fex->fex_freelist)->lh_first) == ((void *)0))) {
1138 if (flags & EX_MALLOCOK0x0010)
1139 goto alloc;
1140
1141 if ((flags & EX_WAITOK0x0001) == 0)
1142 return (NULL((void *)0));
1143 ex->ex_flags |= EXF_FLWANTED0x08;
1144 if (tsleep_nsec(&fex->fex_freelist,
1145 PRIBIO16 | ((flags & EX_CATCH0x0004) ? PCATCH0x100 : 0),
1146 "extnt", INFSLP0xffffffffffffffffULL))
1147 return (NULL((void *)0));
1148 }
1149 rp = LIST_FIRST(&fex->fex_freelist)((&fex->fex_freelist)->lh_first);
1150 LIST_REMOVE(rp, er_link)do { if ((rp)->er_link.le_next != ((void *)0)) (rp)->er_link
.le_next->er_link.le_prev = (rp)->er_link.le_prev; *(rp
)->er_link.le_prev = (rp)->er_link.le_next; ((rp)->er_link
.le_prev) = ((void *)-1); ((rp)->er_link.le_next) = ((void
*)-1); } while (0)
;
1151
1152 /*
1153 * Don't muck with flags after pulling it off the
1154 * freelist; it may be a dynamically allocated
1155 * region pointer that was kindly given to us,
1156 * and we need to preserve that information.
1157 */
1158
1159 return (rp);
1160 }
1161
1162 alloc:
1163 rp = pool_get(&ex_region_pl, (flags & EX_WAITOK0x0001) ? PR_WAITOK0x0001 :
1164 PR_NOWAIT0x0002);
1165 if (rp != NULL((void *)0))
1166 rp->er_flags = ER_ALLOC0x01;
1167
1168 return (rp);
1169}
1170
1171static void
1172extent_free_region_descriptor(struct extent *ex, struct extent_region *rp)
1173{
1174 if (rp->er_flags & ER_DISCARD0x02)
1175 return;
1176
1177 if (ex->ex_flags & EXF_FIXED0x01) {
1178 struct extent_fixed *fex = (struct extent_fixed *)ex;
1179
1180 /*
1181 * If someone's waiting for a region descriptor,
1182 * be nice and give them this one, rather than
1183 * just free'ing it back to the system.
1184 */
1185 if (rp->er_flags & ER_ALLOC0x01) {
1186 if (ex->ex_flags & EXF_FLWANTED0x08) {
1187 /* Clear all but ER_ALLOC flag. */
1188 rp->er_flags = ER_ALLOC0x01;
1189 LIST_INSERT_HEAD(&fex->fex_freelist, rp,do { if (((rp)->er_link.le_next = (&fex->fex_freelist
)->lh_first) != ((void *)0)) (&fex->fex_freelist)->
lh_first->er_link.le_prev = &(rp)->er_link.le_next;
(&fex->fex_freelist)->lh_first = (rp); (rp)->er_link
.le_prev = &(&fex->fex_freelist)->lh_first; } while
(0)
1190 er_link)do { if (((rp)->er_link.le_next = (&fex->fex_freelist
)->lh_first) != ((void *)0)) (&fex->fex_freelist)->
lh_first->er_link.le_prev = &(rp)->er_link.le_next;
(&fex->fex_freelist)->lh_first = (rp); (rp)->er_link
.le_prev = &(&fex->fex_freelist)->lh_first; } while
(0)
;
1191 goto wake_em_up;
1192 } else {
1193 pool_put(&ex_region_pl, rp);
1194 }
1195 } else {
1196 /* Clear all flags. */
1197 rp->er_flags = 0;
1198 LIST_INSERT_HEAD(&fex->fex_freelist, rp, er_link)do { if (((rp)->er_link.le_next = (&fex->fex_freelist
)->lh_first) != ((void *)0)) (&fex->fex_freelist)->
lh_first->er_link.le_prev = &(rp)->er_link.le_next;
(&fex->fex_freelist)->lh_first = (rp); (rp)->er_link
.le_prev = &(&fex->fex_freelist)->lh_first; } while
(0)
;
1199 }
1200
1201 if (ex->ex_flags & EXF_FLWANTED0x08) {
1202 wake_em_up:
1203 ex->ex_flags &= ~EXF_FLWANTED0x08;
1204 wakeup(&fex->fex_freelist);
1205 }
1206 return;
1207 }
1208
1209 /*
1210 * We know it's dynamically allocated if we get here.
1211 */
1212 pool_put(&ex_region_pl, rp);
1213}
1214
1215
1216#if defined(DIAGNOSTIC1) || defined(DDB1) || !defined(_KERNEL1)
1217
1218void
1219extent_print(struct extent *ex)
1220{
1221 extent_print1(ex, printf);
1222}
1223
1224void
1225extent_print1(struct extent *ex,
1226 int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
1227{
1228 struct extent_region *rp;
1229
1230 if (ex == NULL((void *)0))
1231 panic("%s: NULL extent", __func__);
1232
1233#ifdef _KERNEL1
1234 (*pr)("extent `%s' (0x%lx - 0x%lx), flags=%b\n", ex->ex_name,
1235 ex->ex_start, ex->ex_end, ex->ex_flags, EXF_BITS"\20\4FLWANTED\3WANTED\2NOCOALESCE\1FIXED");
1236#else
1237 (*pr)("extent `%s' (0x%lx - 0x%lx), flags = 0x%x\n", ex->ex_name,
1238 ex->ex_start, ex->ex_end, ex->ex_flags);
1239#endif
1240
1241 LIST_FOREACH(rp, &ex->ex_regions, er_link)for((rp) = ((&ex->ex_regions)->lh_first); (rp)!= ((
void *)0); (rp) = ((rp)->er_link.le_next))
1242 (*pr)(" 0x%lx - 0x%lx\n", rp->er_start, rp->er_end);
1243}
1244#endif