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libvirt/src/xen/block_stats.c
Stefan Berger 7b7cb1ecc9 deprecate fclose() and introduce VIR_{FORCE_}FCLOSE() 
Similarly to deprecating close(), I am now deprecating fclose() and
introduce VIR_FORCE_FCLOSE() and VIR_FCLOSE(). Also, fdopen() is replaced with
VIR_FDOPEN().

Most of the files are opened in read-only mode, so usage of
VIR_FORCE_CLOSE() seemed appropriate. Others that are opened in write
mode already had the fclose()<  0 check and I converted those to
VIR_FCLOSE()<  0.

I did not find occurrences of possible double-closed files on the way.
2010-11-16 21:13:29 -05:00

384 lines
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/*
* Linux block and network stats.
*
* Copyright (C) 2007-2009 Red Hat, Inc.
*
* See COPYING.LIB for the License of this software
*
* Richard W.M. Jones <rjones@redhat.com>
*/
#include <config.h>
/* This file only applies on Linux. */
#ifdef __linux__
# include <stdio.h>
# include <stdlib.h>
# include <fcntl.h>
# include <string.h>
# include <unistd.h>
# include <regex.h>
# include <xs.h>
# include "virterror_internal.h"
# include "datatypes.h"
# include "util.h"
# include "block_stats.h"
# include "memory.h"
# include "files.h"
# define VIR_FROM_THIS VIR_FROM_STATS_LINUX
/**
* statsErrorFunc:
* @conn: the connection
* @error: the error number
* @func: the function failing
* @info: extra information string
* @value: extra information number
*
* Handle a stats error.
*/
static void
statsErrorFunc (virConnectPtr conn,
virErrorNumber error, const char *func, const char *info,
int value)
{
char fullinfo[1000];
const char *errmsg;
errmsg = virErrorMsg(error, info);
if (func != NULL) {
snprintf(fullinfo, sizeof (fullinfo) - 1, "%s: %s", func, info);
fullinfo[sizeof (fullinfo) - 1] = 0;
info = fullinfo;
}
virRaiseError(conn, NULL, NULL, VIR_FROM_STATS_LINUX, error,
VIR_ERR_ERROR,
errmsg, info, NULL, value, 0, errmsg, info,
value);
}
/*-------------------- Xen: block stats --------------------*/
# include <linux/major.h>
/* This is normally defined in <linux/major.h> but previously we
* hard-coded it. So if it's not defined, hard-code again.
*/
# ifndef XENVBD_MAJOR
# define XENVBD_MAJOR 202
# endif
static int
xstrtoint64 (char const *s, int base, int64_t *result)
{
long long int lli;
char *p;
errno = 0;
lli = strtoll (s, &p, base);
if (errno || !(*p == 0 || *p == '\n') || p == s || (int64_t) lli != lli)
return -1;
*result = lli;
return 0;
}
static int64_t
read_stat (const char *path)
{
char str[64];
int64_t r;
int i;
FILE *fp;
fp = fopen (path, "r");
if (!fp)
return -1;
/* read, but don't bail out before closing */
i = fread (str, 1, sizeof str - 1, fp);
if (VIR_FCLOSE(fp) != 0 /* disk error */
|| i < 1) /* ensure we read at least one byte */
return -1;
str[i] = '\0'; /* make sure the string is nul-terminated */
if (xstrtoint64 (str, 10, &r) == -1)
return -1;
return r;
}
static int64_t
read_bd_stat (int device, int domid, const char *str)
{
char path[PATH_MAX];
int64_t r;
snprintf (path, sizeof path,
"/sys/bus/xen-backend/devices/vbd-%d-%d/statistics/%s",
domid, device, str);
r = read_stat (path);
if (r >= 0) return r;
snprintf (path, sizeof path,
"/sys/bus/xen-backend/devices/tap-%d-%d/statistics/%s",
domid, device, str);
r = read_stat (path);
if (r >= 0) return r;
snprintf (path, sizeof path,
"/sys/devices/xen-backend/vbd-%d-%d/statistics/%s",
domid, device, str);
r = read_stat (path);
if (r >= 0) return r;
snprintf (path, sizeof path,
"/sys/devices/xen-backend/tap-%d-%d/statistics/%s",
domid, device, str);
r = read_stat (path);
return r;
}
/* In Xenstore, /local/domain/0/backend/vbd/<domid>/<device>/state,
* if available, must be XenbusStateConnected (= 4), otherwise there
* is no connected device.
*/
static int
check_bd_connected (xenUnifiedPrivatePtr priv, int device, int domid)
{
char s[256], *rs;
int r;
unsigned len = 0;
/* This code assumes we're connected if we can't get to
* xenstore, etc.
*/
if (!priv->xshandle) return 1;
snprintf (s, sizeof s, "/local/domain/0/backend/vbd/%d/%d/state",
domid, device);
s[sizeof s - 1] = '\0';
rs = xs_read (priv->xshandle, 0, s, &len);
if (!rs) return 1;
if (len == 0) {
/* Hmmm ... we can get to xenstore but it returns an empty
* string instead of an error. Assume it's not connected
* in this case.
*/
VIR_FREE(rs);
return 0;
}
r = STREQ (rs, "4");
VIR_FREE(rs);
return r;
}
static int
read_bd_stats (virConnectPtr conn, xenUnifiedPrivatePtr priv,
int device, int domid, struct _virDomainBlockStats *stats)
{
stats->rd_req = read_bd_stat (device, domid, "rd_req");
stats->rd_bytes = read_bd_stat (device, domid, "rd_sect");
stats->wr_req = read_bd_stat (device, domid, "wr_req");
stats->wr_bytes = read_bd_stat (device, domid, "wr_sect");
stats->errs = read_bd_stat (device, domid, "oo_req");
/* None of the files were found - it's likely that this version
* of Xen is an old one which just doesn't support stats collection.
*/
if (stats->rd_req == -1 && stats->rd_bytes == -1 &&
stats->wr_req == -1 && stats->wr_bytes == -1 &&
stats->errs == -1) {
statsErrorFunc (conn, VIR_ERR_INTERNAL_ERROR, __FUNCTION__,
"Failed to read any block statistics", domid);
return -1;
}
/* If stats are all zero then either there really isn't any block
* device activity, or there is no connected front end device
* in which case there are no stats.
*/
if (stats->rd_req == 0 && stats->rd_bytes == 0 &&
stats->wr_req == 0 && stats->wr_bytes == 0 &&
stats->errs == 0 &&
!check_bd_connected (priv, device, domid)) {
statsErrorFunc (conn, VIR_ERR_INTERNAL_ERROR, __FUNCTION__,
"Frontend block device not connected", domid);
return -1;
}
/* 'Bytes' was really sectors when we read it. Scale up by
* an assumed sector size.
*/
if (stats->rd_bytes > 0) {
if (stats->rd_bytes >= ((unsigned long long)1)<<(63-9)) {
statsErrorFunc (conn, VIR_ERR_INTERNAL_ERROR, __FUNCTION__,
"stats->rd_bytes would overflow 64 bit counter",
domid);
return -1;
}
stats->rd_bytes *= 512;
}
if (stats->wr_bytes > 0) {
if (stats->wr_bytes >= ((unsigned long long)1)<<(63-9)) {
statsErrorFunc (conn, VIR_ERR_INTERNAL_ERROR, __FUNCTION__,
"stats->wr_bytes would overflow 64 bit counter",
domid);
return -1;
}
stats->wr_bytes *= 512;
}
return 0;
}
static int
disk_re_match(const char *regex, const char *path, int *part)
{
regex_t myreg;
int err;
int retval;
regmatch_t pmatch[3];
retval = 0;
err = regcomp(&myreg, regex, REG_EXTENDED);
if (err != 0)
return 0;
err = regexec(&myreg, path, 3, pmatch, 0);
if (err == 0) {
/* OK, we have a match; see if we have a partition */
*part = 0;
retval = 1;
if (pmatch[1].rm_so != -1) {
if (virStrToLong_i(path + pmatch[1].rm_so, NULL, 10, part) < 0)
retval = 0;
}
}
regfree(&myreg);
return retval;
}
int
xenLinuxDomainDeviceID(virConnectPtr conn, int domid, const char *path)
{
int major, minor;
int part;
int retval;
char *mod_path;
int const scsi_majors[] = { SCSI_DISK0_MAJOR, SCSI_DISK1_MAJOR,
SCSI_DISK2_MAJOR, SCSI_DISK3_MAJOR,
SCSI_DISK4_MAJOR, SCSI_DISK5_MAJOR,
SCSI_DISK6_MAJOR, SCSI_DISK7_MAJOR,
SCSI_DISK8_MAJOR, SCSI_DISK9_MAJOR,
SCSI_DISK10_MAJOR, SCSI_DISK11_MAJOR,
SCSI_DISK12_MAJOR, SCSI_DISK13_MAJOR,
SCSI_DISK14_MAJOR, SCSI_DISK15_MAJOR };
int const ide_majors[] = { IDE0_MAJOR, IDE1_MAJOR, IDE2_MAJOR, IDE3_MAJOR,
IDE4_MAJOR, IDE5_MAJOR, IDE6_MAJOR, IDE7_MAJOR,
IDE8_MAJOR, IDE9_MAJOR };
/*
* Possible block device majors & partition ranges. This
* matches the ranges supported in Xend xen/util/blkif.py
*
* hdNM: N=a-t, M=1-63, major={IDE0_MAJOR -> IDE9_MAJOR}
* sdNM: N=a-z,aa-iv, M=1-15, major={SCSI_DISK0_MAJOR -> SCSI_DISK15_MAJOR}
* xvdNM: N=a-p M=1-15, major=XENVBD_MAJOR
* xvdNM: N=q-z,aa-iz M=1-15, major=(1<<28)
*
* The path for statistics will be
*
* /sys/devices/xen-backend/(vbd|tap)-{domid}-{devid}/statistics/{...}
*/
if (strlen(path) >= 5 && STRPREFIX(path, "/dev/"))
retval = virAsprintf(&mod_path, "%s", path);
else
retval = virAsprintf(&mod_path, "/dev/%s", path);
if (retval < 0) {
virReportOOMError();
return -1;
}
retval = -1;
if (disk_re_match("/dev/sd[a-z]([1-9]|1[0-5])?$", mod_path, &part)) {
major = scsi_majors[(mod_path[7] - 'a') / 16];
minor = ((mod_path[7] - 'a') % 16) * 16 + part;
retval = major * 256 + minor;
}
else if (disk_re_match("/dev/sd[a-h][a-z]([1-9]|1[0-5])?$",
mod_path, &part) ||
disk_re_match("/dev/sdi[a-v]([1-9]|1[0-5])?$",
mod_path, &part)) {
major = scsi_majors[((mod_path[7] - 'a' + 1) * 26 + (mod_path[8] - 'a')) / 16];
minor = (((mod_path[7] - 'a' + 1) * 26 + (mod_path[8] - 'a')) % 16)
* 16 + part;
retval = major * 256 + minor;
}
else if (disk_re_match("/dev/hd[a-t]([1-9]|[1-5][0-9]|6[0-3])?$",
mod_path, &part)) {
major = ide_majors[(mod_path[7] - 'a') / 2];
minor = ((mod_path[7] - 'a') % 2) * 64 + part;
retval = major * 256 + minor;
}
else if (disk_re_match("/dev/xvd[a-p]([1-9]|1[0-5])?$", mod_path, &part))
retval = (202 << 8) + ((mod_path[8] - 'a') << 4) + part;
else if (disk_re_match("/dev/xvd[q-z]([1-9]|1[0-5])?$", mod_path, &part))
retval = (1 << 28) + ((mod_path[8] - 'a') << 8) + part;
else if (disk_re_match("/dev/xvd[a-i][a-z]([1-9]|1[0-5])?$",
mod_path, &part))
retval = (1 << 28) + (((mod_path[8] - 'a' + 1) * 26 + (mod_path[9] - 'a')) << 8) + part;
/*
* OK, we've now checked the common case (things that work); check the
* beginning of the strings for better error messages
*/
else if (strlen(mod_path) >= 7 && STRPREFIX(mod_path, "/dev/sd"))
statsErrorFunc (conn, VIR_ERR_INVALID_ARG, __FUNCTION__,
"invalid path, device names must be in the range sda[1-15] - sdiv[1-15]",
domid);
else if (strlen(mod_path) >= 7 && STRPREFIX(mod_path, "/dev/hd"))
statsErrorFunc (conn, VIR_ERR_INVALID_ARG, __FUNCTION__,
"invalid path, device names must be in the range hda[1-63] - hdt[1-63]",
domid);
else if (strlen(mod_path) >= 8 && STRPREFIX(mod_path, "/dev/xvd"))
statsErrorFunc (conn, VIR_ERR_INVALID_ARG, __FUNCTION__,
"invalid path, device names must be in the range xvda[1-15] - xvdiz[1-15]",
domid);
else
statsErrorFunc (conn, VIR_ERR_INVALID_ARG, __FUNCTION__,
"unsupported path, use xvdN, hdN, or sdN", domid);
VIR_FREE(mod_path);
return retval;
}
int
xenLinuxDomainBlockStats (xenUnifiedPrivatePtr priv,
virDomainPtr dom,
const char *path,
struct _virDomainBlockStats *stats)
{
int device = xenLinuxDomainDeviceID(dom->conn, dom->id, path);
if (device < 0)
return -1;
return read_bd_stats (dom->conn, priv, device, dom->id, stats);
}
#endif /* __linux__ */
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