]>
git.ipfire.org Git - thirdparty/mdadm.git/blob - sysfs.c
f8a9f0b7701e1f7fe61690caf977021c3f421642
2 * sysfs - extract md related information from sysfs. Part of:
3 * mdadm - manage Linux "md" devices aka RAID arrays.
5 * Copyright (C) 2006-2009 Neil Brown <neilb@suse.de>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 * Email: <neilb@suse.de>
30 #define MAX_SYSFS_PATH_LEN 120
32 int load_sys(char *path
, char *buf
, int len
)
34 int fd
= open(path
, O_RDONLY
);
38 n
= read(fd
, buf
, len
);
43 if (n
&& buf
[n
-1] == '\n')
48 void sysfs_free(struct mdinfo
*sra
)
51 struct mdinfo
*sra2
= sra
->next
;
53 struct mdinfo
*d
= sra
->devs
;
62 int sysfs_open(char *devnm
, char *devname
, char *attr
)
64 char fname
[MAX_SYSFS_PATH_LEN
];
67 snprintf(fname
, MAX_SYSFS_PATH_LEN
, "/sys/block/%s/md/", devnm
);
69 strncat(fname
, devname
, MAX_SYSFS_PATH_LEN
- strlen(fname
));
70 strncat(fname
, "/", MAX_SYSFS_PATH_LEN
- strlen(fname
));
72 strncat(fname
, attr
, MAX_SYSFS_PATH_LEN
- strlen(fname
));
73 fd
= open(fname
, O_RDWR
);
74 if (fd
< 0 && errno
== EACCES
)
75 fd
= open(fname
, O_RDONLY
);
79 void sysfs_init_dev(struct mdinfo
*mdi
, unsigned long devid
)
81 snprintf(mdi
->sys_name
,
82 sizeof(mdi
->sys_name
), "dev-%s", devid2kname(devid
));
85 void sysfs_init(struct mdinfo
*mdi
, int fd
, char *devnm
)
90 if (ioctl(fd
, RAID_VERSION
, &vers
) != 0)
96 strcpy(mdi
->sys_name
, devnm
);
99 struct mdinfo
*sysfs_read(int fd
, char *devnm
, unsigned long options
)
101 char fname
[PATH_MAX
];
106 struct mdinfo
*dev
, **devp
;
110 sra
= xcalloc(1, sizeof(*sra
));
111 sysfs_init(sra
, fd
, devnm
);
112 if (sra
->sys_name
[0] == 0) {
117 sprintf(fname
, "/sys/block/%s/md/", sra
->sys_name
);
118 base
= fname
+ strlen(fname
);
121 if (options
& GET_VERSION
) {
122 strcpy(base
, "metadata_version");
123 if (load_sys(fname
, buf
, sizeof(buf
)))
125 if (strncmp(buf
, "none", 4) == 0) {
126 sra
->array
.major_version
=
127 sra
->array
.minor_version
= -1;
128 strcpy(sra
->text_version
, "");
129 } else if (strncmp(buf
, "external:", 9) == 0) {
130 sra
->array
.major_version
= -1;
131 sra
->array
.minor_version
= -2;
132 strcpy(sra
->text_version
, buf
+9);
135 &sra
->array
.major_version
,
136 &sra
->array
.minor_version
);
137 strcpy(sra
->text_version
, buf
);
140 if (options
& GET_LEVEL
) {
141 strcpy(base
, "level");
142 if (load_sys(fname
, buf
, sizeof(buf
)))
144 sra
->array
.level
= map_name(pers
, buf
);
146 if (options
& GET_LAYOUT
) {
147 strcpy(base
, "layout");
148 if (load_sys(fname
, buf
, sizeof(buf
)))
150 sra
->array
.layout
= strtoul(buf
, NULL
, 0);
152 if (options
& GET_DISKS
) {
153 strcpy(base
, "raid_disks");
154 if (load_sys(fname
, buf
, sizeof(buf
)))
156 sra
->array
.raid_disks
= strtoul(buf
, NULL
, 0);
158 if (options
& GET_DEGRADED
) {
159 strcpy(base
, "degraded");
160 if (load_sys(fname
, buf
, sizeof(buf
)))
162 sra
->array
.failed_disks
= strtoul(buf
, NULL
, 0);
164 if (options
& GET_COMPONENT
) {
165 strcpy(base
, "component_size");
166 if (load_sys(fname
, buf
, sizeof(buf
)))
168 sra
->component_size
= strtoull(buf
, NULL
, 0);
169 /* sysfs reports "K", but we want sectors */
170 sra
->component_size
*= 2;
172 if (options
& GET_CHUNK
) {
173 strcpy(base
, "chunk_size");
174 if (load_sys(fname
, buf
, sizeof(buf
)))
176 sra
->array
.chunk_size
= strtoul(buf
, NULL
, 0);
178 if (options
& GET_CACHE
) {
179 strcpy(base
, "stripe_cache_size");
180 if (load_sys(fname
, buf
, sizeof(buf
)))
181 /* Probably level doesn't support it */
184 sra
->cache_size
= strtoul(buf
, NULL
, 0);
186 if (options
& GET_MISMATCH
) {
187 strcpy(base
, "mismatch_cnt");
188 if (load_sys(fname
, buf
, sizeof(buf
)))
190 sra
->mismatch_cnt
= strtoul(buf
, NULL
, 0);
192 if (options
& GET_SAFEMODE
) {
199 strcpy(base
, "safe_mode_delay");
200 if (load_sys(fname
, buf
, sizeof(buf
)))
203 /* remove a period, and count digits after it */
205 for (i
= 0; i
< len
; i
++) {
207 if (isdigit(buf
[i
])) {
212 } else if (buf
[i
] == '.') {
217 msec
= strtoul(buf
, NULL
, 10);
218 msec
= (msec
* 1000) / scale
;
219 sra
->safe_mode_delay
= msec
;
221 if (options
& GET_BITMAP_LOCATION
) {
222 strcpy(base
, "bitmap/location");
223 if (load_sys(fname
, buf
, sizeof(buf
)))
225 if (strncmp(buf
, "file", 4) == 0)
226 sra
->bitmap_offset
= 1;
227 else if (strncmp(buf
, "none", 4) == 0)
228 sra
->bitmap_offset
= 0;
229 else if (buf
[0] == '+')
230 sra
->bitmap_offset
= strtol(buf
+1, NULL
, 10);
235 if (options
& GET_ARRAY_STATE
) {
236 strcpy(base
, "array_state");
237 if (load_sys(fname
, sra
->sysfs_array_state
,
238 sizeof(sra
->sysfs_array_state
)))
241 sra
->sysfs_array_state
[0] = 0;
243 if (! (options
& GET_DEVS
))
246 /* Get all the devices as well */
248 dir
= opendir(fname
);
251 sra
->array
.spare_disks
= 0;
255 while ((de
= readdir(dir
)) != NULL
) {
257 if (de
->d_ino
== 0 ||
258 strncmp(de
->d_name
, "dev-", 4) != 0)
260 strcpy(base
, de
->d_name
);
261 dbase
= base
+ strlen(base
);
264 dev
= xmalloc(sizeof(*dev
));
266 /* Always get slot, major, minor */
267 strcpy(dbase
, "slot");
268 if (load_sys(fname
, buf
, sizeof(buf
))) {
269 /* hmm... unable to read 'slot' maybe the device
272 strcpy(dbase
, "block");
273 if (readlink(fname
, buf
, sizeof(buf
)) < 0 &&
274 errno
!= ENAMETOOLONG
) {
275 /* ...yup device is gone */
279 /* slot is unreadable but 'block' link
280 * still intact... something bad is happening
288 strcpy(dev
->sys_name
, de
->d_name
);
289 dev
->disk
.raid_disk
= strtoul(buf
, &ep
, 10);
290 if (*ep
) dev
->disk
.raid_disk
= -1;
292 strcpy(dbase
, "block/dev");
293 if (load_sys(fname
, buf
, sizeof(buf
))) {
294 /* assume this is a stale reference to a hot
300 sra
->array
.nr_disks
++;
301 sscanf(buf
, "%d:%d", &dev
->disk
.major
, &dev
->disk
.minor
);
303 /* special case check for block devices that can go 'offline' */
304 strcpy(dbase
, "block/device/state");
305 if (load_sys(fname
, buf
, sizeof(buf
)) == 0 &&
306 strncmp(buf
, "offline", 7) == 0) {
311 /* finally add this disk to the array */
316 if (options
& GET_OFFSET
) {
317 strcpy(dbase
, "offset");
318 if (load_sys(fname
, buf
, sizeof(buf
)))
320 dev
->data_offset
= strtoull(buf
, NULL
, 0);
321 strcpy(dbase
, "new_offset");
322 if (load_sys(fname
, buf
, sizeof(buf
)) == 0)
323 dev
->new_data_offset
= strtoull(buf
, NULL
, 0);
325 dev
->new_data_offset
= dev
->data_offset
;
327 if (options
& GET_SIZE
) {
328 strcpy(dbase
, "size");
329 if (load_sys(fname
, buf
, sizeof(buf
)))
331 dev
->component_size
= strtoull(buf
, NULL
, 0) * 2;
333 if (options
& GET_STATE
) {
335 strcpy(dbase
, "state");
336 if (load_sys(fname
, buf
, sizeof(buf
)))
338 if (strstr(buf
, "in_sync"))
339 dev
->disk
.state
|= (1<<MD_DISK_SYNC
);
340 if (strstr(buf
, "faulty"))
341 dev
->disk
.state
|= (1<<MD_DISK_FAULTY
);
342 if (dev
->disk
.state
== 0)
343 sra
->array
.spare_disks
++;
345 if (options
& GET_ERROR
) {
346 strcpy(buf
, "errors");
347 if (load_sys(fname
, buf
, sizeof(buf
)))
349 dev
->errors
= strtoul(buf
, NULL
, 0);
362 int sysfs_attr_match(const char *attr
, const char *str
)
364 /* See if attr, read from a sysfs file, matches
365 * str. They must either be the same, or attr can
366 * have a trailing newline or comma
368 while (*attr
&& *str
&& *attr
== *str
) {
373 if (*str
|| (*attr
&& *attr
!= ',' && *attr
!= '\n'))
378 int sysfs_match_word(const char *word
, char **list
)
381 for (n
=0; list
[n
]; n
++)
382 if (sysfs_attr_match(word
, list
[n
]))
387 unsigned long long get_component_size(int fd
)
389 /* Find out the component size of the array.
390 * We cannot trust GET_ARRAY_INFO ioctl as it's
391 * size field is only 32bits.
392 * So look in /sys/block/mdXXX/md/component_size
394 * This returns in units of sectors.
397 char fname
[MAX_SYSFS_PATH_LEN
];
401 if (major(stb
.st_rdev
) != (unsigned)get_mdp_major())
402 snprintf(fname
, MAX_SYSFS_PATH_LEN
,
403 "/sys/block/md%d/md/component_size",
404 (int)minor(stb
.st_rdev
));
406 snprintf(fname
, MAX_SYSFS_PATH_LEN
,
407 "/sys/block/md_d%d/md/component_size",
408 (int)minor(stb
.st_rdev
)>>MdpMinorShift
);
409 fd
= open(fname
, O_RDONLY
);
412 n
= read(fd
, fname
, sizeof(fname
));
414 if (n
< 0 || n
== sizeof(fname
))
417 return strtoull(fname
, NULL
, 10) * 2;
420 int sysfs_set_str(struct mdinfo
*sra
, struct mdinfo
*dev
,
421 char *name
, char *val
)
423 char fname
[MAX_SYSFS_PATH_LEN
];
427 snprintf(fname
, MAX_SYSFS_PATH_LEN
, "/sys/block/%s/md/%s/%s",
428 sra
->sys_name
, dev
?dev
->sys_name
:"", name
);
429 fd
= open(fname
, O_WRONLY
);
432 n
= write(fd
, val
, strlen(val
));
434 if (n
!= strlen(val
)) {
435 dprintf("failed to write '%s' to '%s' (%s)\n",
436 val
, fname
, strerror(errno
));
442 int sysfs_set_num(struct mdinfo
*sra
, struct mdinfo
*dev
,
443 char *name
, unsigned long long val
)
446 sprintf(valstr
, "%llu", val
);
447 return sysfs_set_str(sra
, dev
, name
, valstr
);
450 int sysfs_set_num_signed(struct mdinfo
*sra
, struct mdinfo
*dev
,
451 char *name
, long long val
)
454 sprintf(valstr
, "%lli", val
);
455 return sysfs_set_str(sra
, dev
, name
, valstr
);
458 int sysfs_uevent(struct mdinfo
*sra
, char *event
)
460 char fname
[MAX_SYSFS_PATH_LEN
];
464 snprintf(fname
, MAX_SYSFS_PATH_LEN
, "/sys/block/%s/uevent",
466 fd
= open(fname
, O_WRONLY
);
469 n
= write(fd
, event
, strlen(event
));
471 if (n
!= (int)strlen(event
)) {
472 dprintf("failed to write '%s' to '%s' (%s)\n",
473 event
, fname
, strerror(errno
));
479 int sysfs_attribute_available(struct mdinfo
*sra
, struct mdinfo
*dev
, char *name
)
481 char fname
[MAX_SYSFS_PATH_LEN
];
484 snprintf(fname
, MAX_SYSFS_PATH_LEN
, "/sys/block/%s/md/%s/%s",
485 sra
->sys_name
, dev
?dev
->sys_name
:"", name
);
487 return stat(fname
, &st
) == 0;
490 int sysfs_get_fd(struct mdinfo
*sra
, struct mdinfo
*dev
,
493 char fname
[MAX_SYSFS_PATH_LEN
];
496 snprintf(fname
, MAX_SYSFS_PATH_LEN
, "/sys/block/%s/md/%s/%s",
497 sra
->sys_name
, dev
?dev
->sys_name
:"", name
);
498 fd
= open(fname
, O_RDWR
);
500 fd
= open(fname
, O_RDONLY
);
504 int sysfs_fd_get_ll(int fd
, unsigned long long *val
)
511 n
= read(fd
, buf
, sizeof(buf
));
512 if (n
<= 0 || n
== sizeof(buf
))
515 *val
= strtoull(buf
, &ep
, 0);
516 if (ep
== buf
|| (*ep
!= 0 && *ep
!= '\n' && *ep
!= ' '))
521 int sysfs_get_ll(struct mdinfo
*sra
, struct mdinfo
*dev
,
522 char *name
, unsigned long long *val
)
527 fd
= sysfs_get_fd(sra
, dev
, name
);
530 n
= sysfs_fd_get_ll(fd
, val
);
535 int sysfs_fd_get_two(int fd
, unsigned long long *v1
, unsigned long long *v2
)
537 /* two numbers in this sysfs file, either
547 n
= read(fd
, buf
, sizeof(buf
));
548 if (n
<= 0 || n
== sizeof(buf
))
551 *v1
= strtoull(buf
, &ep
, 0);
552 if (ep
== buf
|| (*ep
!= 0 && *ep
!= '\n' && *ep
!= ' '))
554 while (*ep
== ' ' || *ep
== '/' || *ep
== '(')
556 *v2
= strtoull(ep
, &ep2
, 0);
557 if (ep2
== ep
|| (*ep2
!= 0 && *ep2
!= '\n' && *ep2
!= ' ' && *ep2
!= ')')) {
564 int sysfs_get_two(struct mdinfo
*sra
, struct mdinfo
*dev
,
565 char *name
, unsigned long long *v1
, unsigned long long *v2
)
570 fd
= sysfs_get_fd(sra
, dev
, name
);
573 n
= sysfs_fd_get_two(fd
, v1
, v2
);
578 int sysfs_fd_get_str(int fd
, char *val
, int size
)
583 n
= read(fd
, val
, size
);
584 if (n
<= 0 || n
== size
)
590 int sysfs_get_str(struct mdinfo
*sra
, struct mdinfo
*dev
,
591 char *name
, char *val
, int size
)
596 fd
= sysfs_get_fd(sra
, dev
, name
);
599 n
= sysfs_fd_get_str(fd
, val
, size
);
604 int sysfs_set_safemode(struct mdinfo
*sra
, unsigned long ms
)
613 sprintf(delay
, "%ld.%03ld\n", sec
, msec
);
614 /* this '\n' ^ needed for kernels older than 2.6.28 */
615 return sysfs_set_str(sra
, NULL
, "safe_mode_delay", delay
);
618 int sysfs_set_array(struct mdinfo
*info
, int vers
)
622 int raid_disks
= info
->array
.raid_disks
;
625 if (info
->array
.major_version
== -1 &&
626 info
->array
.minor_version
== -2) {
629 strcat(strcpy(ver
, "external:"), info
->text_version
);
631 /* meta version might already be set if we are setting
632 * new geometry for a reshape. In that case we don't
633 * want to over-write the 'readonly' flag that is
634 * stored in the metadata version. So read the current
635 * version first, and preserve the flag
637 if (sysfs_get_str(info
, NULL
, "metadata_version",
639 if (strlen(buf
) >= 9 && buf
[9] == '-')
642 if ((vers
% 100) < 2 ||
643 sysfs_set_str(info
, NULL
, "metadata_version",
645 pr_err("This kernel does not support external metadata.\n");
649 if (info
->array
.level
< 0)
650 return 0; /* FIXME */
651 rv
|= sysfs_set_str(info
, NULL
, "level",
652 map_num(pers
, info
->array
.level
));
653 if (info
->reshape_active
&& info
->delta_disks
!= UnSet
)
654 raid_disks
-= info
->delta_disks
;
655 rv
|= sysfs_set_num(info
, NULL
, "raid_disks", raid_disks
);
656 rv
|= sysfs_set_num(info
, NULL
, "chunk_size", info
->array
.chunk_size
);
657 rv
|= sysfs_set_num(info
, NULL
, "layout", info
->array
.layout
);
658 rv
|= sysfs_set_num(info
, NULL
, "component_size", info
->component_size
/2);
659 if (info
->custom_array_size
) {
662 rc
= sysfs_set_num(info
, NULL
, "array_size",
663 info
->custom_array_size
/2);
664 if (rc
&& errno
== ENOENT
) {
665 pr_err("This kernel does not have the md/array_size attribute, the array may be larger than expected\n");
671 if (info
->array
.level
> 0)
672 rv
|= sysfs_set_num(info
, NULL
, "resync_start", info
->resync_start
);
674 if (info
->reshape_active
) {
675 rv
|= sysfs_set_num(info
, NULL
, "reshape_position",
676 info
->reshape_progress
);
677 rv
|= sysfs_set_num(info
, NULL
, "chunk_size", info
->new_chunk
);
678 rv
|= sysfs_set_num(info
, NULL
, "layout", info
->new_layout
);
679 rv
|= sysfs_set_num(info
, NULL
, "raid_disks",
680 info
->array
.raid_disks
);
681 /* We don't set 'new_level' here. That can only happen
682 * once the reshape completes.
688 int sysfs_add_disk(struct mdinfo
*sra
, struct mdinfo
*sd
, int resume
)
695 sprintf(dv
, "%d:%d", sd
->disk
.major
, sd
->disk
.minor
);
696 rv
= sysfs_set_str(sra
, NULL
, "new_dev", dv
);
700 memset(nm
, 0, sizeof(nm
));
701 dname
= devid2kname(makedev(sd
->disk
.major
, sd
->disk
.minor
));
702 strcpy(sd
->sys_name
, "dev-");
703 strcpy(sd
->sys_name
+4, dname
);
705 /* test write to see if 'recovery_start' is available */
706 if (resume
&& sd
->recovery_start
< MaxSector
&&
707 sysfs_set_num(sra
, sd
, "recovery_start", 0)) {
708 sysfs_set_str(sra
, sd
, "state", "remove");
712 rv
= sysfs_set_num(sra
, sd
, "offset", sd
->data_offset
);
713 rv
|= sysfs_set_num(sra
, sd
, "size", (sd
->component_size
+1) / 2);
714 if (sra
->array
.level
!= LEVEL_CONTAINER
) {
715 if (sd
->recovery_start
== MaxSector
)
716 /* This can correctly fail if array isn't started,
717 * yet, so just ignore status for now.
719 sysfs_set_str(sra
, sd
, "state", "insync");
720 if (sd
->disk
.raid_disk
>= 0)
721 rv
|= sysfs_set_num(sra
, sd
, "slot", sd
->disk
.raid_disk
);
723 sysfs_set_num(sra
, sd
, "recovery_start", sd
->recovery_start
);
729 int sysfs_disk_to_sg(int fd
)
731 /* from an open block device, try find and open its corresponding
732 * scsi_generic interface
737 char sg_major_minor
[10];
741 int major
, minor
, rv
;
746 snprintf(path
, sizeof(path
), "/sys/dev/block/%d:%d/device",
747 major(st
.st_rdev
), minor(st
.st_rdev
));
755 if (strncmp("scsi_generic:", de
->d_name
,
756 strlen("scsi_generic:")) == 0)
765 snprintf(sg_path
, sizeof(sg_path
), "%s/%s/dev", path
, de
->d_name
);
766 fd
= open(sg_path
, O_RDONLY
);
770 rv
= read(fd
, sg_major_minor
, sizeof(sg_major_minor
));
772 if (rv
< 0 || rv
== sizeof(sg_major_minor
))
775 sg_major_minor
[rv
- 1] = '\0';
777 c
= strchr(sg_major_minor
, ':');
780 major
= strtol(sg_major_minor
, NULL
, 10);
781 minor
= strtol(c
, NULL
, 10);
782 snprintf(path
, sizeof(path
), "/dev/.tmp.md.%d:%d:%d",
783 (int) getpid(), major
, minor
);
784 if (mknod(path
, S_IFCHR
|0600, makedev(major
, minor
))==0) {
785 fd
= open(path
, O_RDONLY
);
794 int sysfs_disk_to_scsi_id(int fd
, __u32
*id
)
796 /* from an open block device, try to retrieve it scsi_id */
801 int host
, bus
, target
, lun
;
806 snprintf(path
, sizeof(path
), "/sys/dev/block/%d:%d/device/scsi_device",
807 major(st
.st_rdev
), minor(st
.st_rdev
));
813 for (de
= readdir(dir
); de
; de
= readdir(dir
)) {
816 if (de
->d_type
!= DT_DIR
)
819 count
= sscanf(de
->d_name
, "%d:%d:%d:%d", &host
, &bus
, &target
, &lun
);
828 *id
= (host
<< 24) | (bus
<< 16) | (target
<< 8) | (lun
<< 0);
832 int sysfs_unique_holder(char *devnm
, long rdev
)
834 /* Check that devnm is a holder of rdev,
835 * and is the only holder.
836 * we should be locked against races by
839 * 0 - not unique, not even a holder
840 * 1 - unique, this is the only holder.
841 * 2/3 - not unique, there is another holder
842 * -1 - error, cannot find the holders
849 sprintf(dirname
, "/sys/dev/block/%d:%d/holders",
850 major(rdev
), minor(rdev
));
851 dir
= opendir(dirname
);
855 while ((de
= readdir(dir
)) != NULL
) {
862 if (de
->d_name
[0] == '.')
864 strcpy(dirname
+l
, "/");
865 strcat(dirname
+l
, de
->d_name
);
866 n
= readlink(dirname
, buf
, sizeof(buf
)-1);
870 sl
= strrchr(buf
, '/');
875 if (strcmp(devnm
, sl
) == 0)
884 int sysfs_freeze_array(struct mdinfo
*sra
)
886 /* Try to freeze resync/rebuild on this array/container.
887 * Return -1 if the array is busy,
888 * return 0 if this kernel doesn't support 'frozen'
889 * return 1 if it worked.
893 if (!sysfs_attribute_available(sra
, NULL
, "sync_action"))
894 return 1; /* no sync_action == frozen */
895 if (sysfs_get_str(sra
, NULL
, "sync_action", buf
, 20) <= 0)
897 if (strcmp(buf
, "frozen\n") == 0)
900 if (strcmp(buf
, "idle\n") != 0 && strcmp(buf
, "recover\n") != 0)
902 if (sysfs_set_str(sra
, NULL
, "sync_action", "frozen") < 0)
907 int sysfs_wait(int fd
, int *msec
)
909 /* Wait up to '*msec' for fd to have an exception condition.
910 * if msec == NULL, wait indefinitely.
917 n
= select(fd
+1, NULL
, NULL
, &fds
, NULL
);
921 struct timeval start
, end
, tv
;
922 gettimeofday(&start
, NULL
);
925 tv
.tv_usec
= (*msec
)*1000;
927 tv
.tv_sec
= (*msec
)/1000;
930 n
= select(fd
+1, NULL
, NULL
, &fds
, &tv
);
931 gettimeofday(&end
, NULL
);
932 end
.tv_sec
-= start
.tv_sec
;
933 *msec
-= (end
.tv_sec
* 1000 + end
.tv_usec
/1000
934 - start
.tv_usec
/1000) + 1;