[libvirt] [RFC] [PATCH v3 5/6] make /proc/meminfo isolate with host through fuse
Daniel P. Berrange
berrange at redhat.com
Tue Sep 25 18:45:02 UTC 2012
On Tue, Sep 11, 2012 at 10:54:51AM +0800, Gao feng wrote:
> with this patch,container's meminfo will be shown based on
> containers' mem cgroup.
>
> Right now,it's impossible to virtualize all values in meminfo,
> I collect some values such as MemTotal,MemFree,Cached,Active,
> Inactive,Active(anon),Inactive(anon),Active(file),Inactive(anon),
> Active(file),Inactive(file),Unevictable,SwapTotal,SwapFree.
>
> if I miss something, please let me know.
>
> Signed-off-by: Gao feng <gaofeng at cn.fujitsu.com>
> ---
> src/lxc/lxc_cgroup.c | 151 +++++++++++++++++++++++++++++++++++
> src/lxc/lxc_cgroup.h | 1 +
> src/lxc/lxc_fuse.c | 216 +++++++++++++++++++++++++++++++++++++++++++++++--
> src/lxc/lxc_fuse.h | 14 +++
> 4 files changed, 373 insertions(+), 9 deletions(-)
>
> diff --git a/src/lxc/lxc_cgroup.c b/src/lxc/lxc_cgroup.c
> index aca6309..2fd1b10 100644
> --- a/src/lxc/lxc_cgroup.c
> +++ b/src/lxc/lxc_cgroup.c
> @@ -23,6 +23,8 @@
>
> #include "lxc_cgroup.h"
> #include "lxc_container.h"
> +#include "lxc_fuse.h"
> +#include "virfile.h"
> #include "virterror_internal.h"
> #include "logging.h"
> #include "memory.h"
> @@ -138,6 +140,155 @@ cleanup:
> }
>
>
> +static int virLXCCgroupGetMemSwapUsage(virCgroupPtr cgroup,
> + unsigned long long *usage)
> +{
> + return virCgroupGetMemSwapUsage(cgroup, usage);
> +}
> +
> +
> +static int virLXCCgroupGetMemSwapTotal(virCgroupPtr cgroup,
> + unsigned long long *total)
> +{
> + return virCgroupGetMemSwapHardLimit(cgroup, total);
> +}
> +
> +
> +static int virLXCCgroupGetMemUsage(virCgroupPtr cgroup,
> + unsigned long long *usage)
> +{
> + int ret;
> + unsigned long memUsage;
> +
> + ret = virCgroupGetMemoryUsage(cgroup, &memUsage);
> + *usage = (unsigned long long) memUsage;
> +
> + return ret;
> +}
> +
> +
> +static int virLXCCgroupGetMemTotal(virCgroupPtr cgroup,
> + unsigned long long *total)
> +{
> + return virCgroupGetMemoryHardLimit(cgroup, total);
> +}
> +
> +
> +static int virLXCCgroupGetMemStat(virCgroupPtr cgroup,
> + unsigned long long *meminfo)
> +{
> + int ret = 0;
> + FILE *statfd = NULL;
> + char *statFile = NULL;
> + char line[1024];
> +
> + ret = virCgroupPathOfController(cgroup, VIR_CGROUP_CONTROLLER_MEMORY,
> + "memory.stat", &statFile);
> + if (ret < 0) {
> + virReportSystemError(-ret, "%s",
> + _("cannot get the path of MEMORY cgroup controller"));
> + return ret;
> + }
> +
> + statfd = fopen(statFile, "r");
> + if (statfd == NULL) {
> + ret = -ENOENT;
> + goto out_free;
> + }
> +
> + while (fgets(line, sizeof(line), statfd) != NULL) {
> + char *value = strchr(line, ' ');
> + char *nl = value ? strchr(line, '\n') : NULL;
> + unsigned long long stat_value;
> +
> + if (!value)
> + continue;
> +
> + if (nl)
> + *nl = '\0';
> +
> + *value = '\0';
> +
> + if ((ret = virStrToLong_ull(value + 1, NULL, 10, &stat_value)) < 0)
> + goto out;
> +
> + if (STREQ(line, "cache"))
> + meminfo[CACHED] = stat_value >> 10;
> + else if (STREQ(line, "inactive_anon"))
> + meminfo[INACTIVE_ANON] = stat_value >> 10;
> + else if (STREQ(line, "active_anon"))
> + meminfo[ACTIVE_ANON] = stat_value >> 10;
> + else if (STREQ(line, "inactive_file"))
> + meminfo[INACTIVE_FILE] = stat_value >> 10;
> + else if (STREQ(line, "active_file"))
> + meminfo[ACTIVE_FILE] = stat_value >> 10;
> + else if (STREQ(line, "unevictable"))
> + meminfo[UNEVICTABLE] = stat_value >> 10;
> + }
> + ret = 0;
> +out:
> + VIR_FORCE_FCLOSE(statfd);
> +out_free:
> + VIR_FREE(statFile);
> + return ret;
> +}
> +
> +
> +int virLXCCgroupGetMeminfo(unsigned long long *meminfo)
> +{
> + int ret;
> + virCgroupPtr cgroup;
> +
> + ret = virCgroupGetAppRoot(&cgroup);
> + if (ret < 0) {
> + virReportSystemError(-ret, "%s",
> + _("Unable to get cgroup for container"));
> + return ret;
> + }
> +
> + ret = virLXCCgroupGetMemStat(cgroup, meminfo);
> + if (ret < 0) {
> + virReportSystemError(-ret, "%s",
> + _("Unable to get memory cgroup stat info"));
> + goto out;
> + }
> +
> + ret = virLXCCgroupGetMemTotal(cgroup, &meminfo[MEMTOTAL]);
> + if (ret < 0) {
> + virReportSystemError(-ret, "%s",
> + _("Unable to get memory cgroup total"));
> + goto out;
> + }
> +
> + ret = virLXCCgroupGetMemUsage(cgroup, &meminfo[MEMUSAGE]);
> + if (ret < 0) {
> + virReportSystemError(-ret, "%s",
> + _("Unable to get memory cgroup stat usage"));
> + goto out;
> + }
> +
> + ret = virLXCCgroupGetMemSwapTotal(cgroup, &meminfo[SWAPTOTAL]);
> + if (ret < 0) {
> + virReportSystemError(-ret, "%s",
> + _("Unable to get memory cgroup stat swaptotal"));
> + goto out;
> + }
> +
> + ret = virLXCCgroupGetMemSwapUsage(cgroup, &meminfo[SWAPUSAGE]);
> + if (ret < 0) {
> + virReportSystemError(-ret, "%s",
> + _("Unable to get memory cgroup stat swapusage"));
> + goto out;
> + }
> +
> + ret = 0;
> +out:
> + virCgroupFree(&cgroup);
> +
> + return ret;
> +}
> +
> +
> typedef struct _virLXCCgroupDevicePolicy virLXCCgroupDevicePolicy;
> typedef virLXCCgroupDevicePolicy *virLXCCgroupDevicePolicyPtr;
>
> diff --git a/src/lxc/lxc_cgroup.h b/src/lxc/lxc_cgroup.h
> index 8ff1015..eccdcba 100644
> --- a/src/lxc/lxc_cgroup.h
> +++ b/src/lxc/lxc_cgroup.h
> @@ -25,5 +25,6 @@
> # include "domain_conf.h"
>
> int virLXCCgroupSetup(virDomainDefPtr def);
> +int virLXCCgroupGetMeminfo(unsigned long long *meminfo);
>
> #endif /* __VIR_LXC_CGROUP_H__ */
> diff --git a/src/lxc/lxc_fuse.c b/src/lxc/lxc_fuse.c
> index 868a698..a073e30 100644
> --- a/src/lxc/lxc_fuse.c
> +++ b/src/lxc/lxc_fuse.c
> @@ -29,25 +29,48 @@
> #include <sys/mount.h>
>
> #include "lxc_fuse.h"
> +#include "lxc_cgroup.h"
> #include "virterror_internal.h"
> +#include "virfile.h"
>
> #define VIR_FROM_THIS VIR_FROM_LXC
>
> #if HAVE_FUSE
>
> +static const char *meminfo_path = "/meminfo";
> +
> static int lxcProcGetattr(const char *path, struct stat *stbuf)
> {
> - int res = 0;
> + int res;
> + char *mempath = NULL;
> + struct stat sb;
>
> memset(stbuf, 0, sizeof(struct stat));
> + if ((res = virAsprintf(&mempath, "/proc/%s", path)) < 0) {
> + virReportOOMError();
> + return res;
> + }
> +
> + res = 0;
>
> if (STREQ(path, "/")) {
> stbuf->st_mode = S_IFDIR | 0755;
> stbuf->st_nlink = 2;
> + } else if (STREQ(path, meminfo_path)) {
> + stat(mempath, &sb);
> + stbuf->st_mode = sb.st_mode;
> + stbuf->st_nlink = 1;
> + stbuf->st_blksize = sb.st_blksize;
> + stbuf->st_blocks = sb.st_blocks;
> + stbuf->st_size = sb.st_size;
> + stbuf->st_atime = sb.st_atime;
> + stbuf->st_ctime = sb.st_ctime;
> + stbuf->st_mtime = sb.st_mtime;
> } else {
> res = -ENOENT;
> }
>
> + VIR_FREE(mempath);
> return res;
> }
>
> @@ -61,23 +84,198 @@ static int lxcProcReaddir(const char *path, void *buf,
>
> filler(buf, ".", NULL, 0);
> filler(buf, "..", NULL, 0);
> + filler(buf, meminfo_path + 1, NULL, 0);
>
> return 0;
> }
>
> -static int lxcProcOpen(const char *path ATTRIBUTE_UNUSED,
> - struct fuse_file_info *fi ATTRIBUTE_UNUSED)
> +static int lxcProcOpen(const char *path,
> + struct fuse_file_info *fi)
> +{
> + if (!STREQ(path, meminfo_path))
> + return -ENOENT;
> +
> + if ((fi->flags & 3) != O_RDONLY)
> + return -EACCES;
> +
> + return 0;
> +}
> +
> +static int lxcProcHostRead(char *path, char *buf, size_t size, off_t offset)
> {
> - return -ENOENT;
> + int fd;
> + int res;
> +
> + fd = open(path, O_RDONLY);
> + if (fd == -1)
> + return -errno;
> +
> + res = pread(fd, buf, size, offset);
> + if (res == -1)
> + res = -errno;
> +
> + VIR_FORCE_CLOSE(fd);
> + return res;
> }
>
> -static int lxcProcRead(const char *path ATTRIBUTE_UNUSED,
> - char *buf ATTRIBUTE_UNUSED,
> - size_t size ATTRIBUTE_UNUSED,
> - off_t offset ATTRIBUTE_UNUSED,
> +static int lxcProcReadMeminfo(char *hostpath, virDomainDefPtr def,
> + char *buf, size_t size, off_t offset)
> +{
> + int copied = 0;
> + int res = 0;
> + FILE *fd = NULL;
> + char line[1024];
> + unsigned long long meminfo[MEMMAX];
> + memset(meminfo, 0, sizeof(meminfo));
> +
> + if ((res = virLXCCgroupGetMeminfo(meminfo)) < 0)
> + return res;
> +
> + fd = fopen(hostpath, "r");
> + if (fd == NULL) {
> + virReportSystemError(errno, _("Cannot open %s"), hostpath);
> + res = -errno;
> + goto out;
> + }
> +
> + fseek(fd, offset, SEEK_SET);
> +
> + while (copied < size && fgets(line, sizeof(line), fd) != NULL) {
> + int len = 0;
> + char *new_line = NULL;
> + char *ptr = strchr(line, ':');
> + if (ptr) {
> + *ptr = '\0';
> + new_line = line;
> +
> + if (STREQ(line, "MemTotal") &&
> + (def->mem.hard_limit || def->mem.max_balloon)) {
> + if ((res = virAsprintf(&new_line, "MemTotal: %8llu KB\n",
> + meminfo[MEMTOTAL])) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "MemFree") &&
> + (def->mem.hard_limit || def->mem.max_balloon)) {
> + if ((res = virAsprintf(&new_line, "MemFree: %8llu KB\n",
> + (meminfo[MEMTOTAL] - meminfo[MEMUSAGE]))) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "Buffers")) {
> + if ((res = virAsprintf(&new_line, "Buffers: %8d KB\n", 0)) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "Cached")) {
> + if ((res = virAsprintf(&new_line, "Cached: %8llu KB\n",
> + meminfo[CACHED])) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "Active")) {
> + if ((res = virAsprintf(&new_line, "Active: %8llu KB\n",
> + (meminfo[ACTIVE_ANON] + meminfo[ACTIVE_FILE]))) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "Inactive")) {
> + if ((res = virAsprintf(&new_line, "Inactive: %8llu KB\n",
> + (meminfo[INACTIVE_ANON] + meminfo[INACTIVE_FILE]))) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "Active(anon)")) {
> + if ((res = virAsprintf(&new_line, "Active(anon): %8llu KB\n",
> + meminfo[ACTIVE_ANON])) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "Inactive(anon)")) {
> + if ((res = virAsprintf(&new_line, "Inactive(anon): %8llu KB\n",
> + meminfo[INACTIVE_ANON])) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "Active(file)")) {
> + if ((res = virAsprintf(&new_line, "Active(file): %8llu KB\n",
> + meminfo[ACTIVE_FILE])) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "Inactive(file)")) {
> + if ((res = virAsprintf(&new_line, "Inactive(file): %8llu KB\n",
> + meminfo[INACTIVE_FILE])) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "Unevictable")) {
> + if ((res = virAsprintf(&new_line, "Unevictable: %8llu KB\n",
> + meminfo[UNEVICTABLE])) < 0) {
> + goto out_oom;
> + }
> + } else if (STREQ(line, "SwapTotal") && def->mem.swap_hard_limit) {
> + if ((res = virAsprintf(&new_line, "SwapTotal: %8llu KB\n",
> + (meminfo[SWAPTOTAL] - meminfo[MEMTOTAL]))) < 0){
> + goto out_oom;
> + }
> + } else if (STREQ(line, "SwapFree") && def->mem.swap_hard_limit) {
> + if ((res = virAsprintf(&new_line, "SwapFree: %8llu KB\n",
> + (meminfo[SWAPTOTAL] - meminfo[MEMTOTAL] -
> + meminfo[SWAPUSAGE] + meminfo[MEMUSAGE]))) < 0) {
> + goto out_oom;
> + }
> + }
> + *ptr=':';
> + }
> +
> + len = strlen(new_line);
> +
> + if (copied + len > size)
> + len = size - copied;
> +
> + memcpy(buf + copied, new_line, len);
> + copied += len;
> + memset(line, 0, sizeof(line));
> + if (new_line != line)
> + VIR_FREE(new_line);
> + }
> + res = copied;
> +
> +out:
> + VIR_FORCE_FCLOSE(fd);
> + return res;
> +
> +out_oom:
> + virReportOOMError();
> + goto out;
> +}
> +
> +static int lxcProcRead(const char *path,
> + char *buf,
> + size_t size,
> + off_t offset,
> struct fuse_file_info *fi ATTRIBUTE_UNUSED)
> {
> - return -ENOENT;
> + int res = 0;
> + char *hostpath = NULL;
> + struct fuse_context *context = NULL;
> + virDomainDefPtr def = NULL;
> +
> + if ((res = virAsprintf(&hostpath, "/proc/%s", path)) < 0) {
> + virReportOOMError();
> + return res;
> + }
> +
> + context = fuse_get_context();
> + def = (virDomainDefPtr)context->private_data;
> +
> + if (STREQ(path, meminfo_path)) {
> + res = lxcProcReadMeminfo(hostpath, def, buf, size, offset);
> + } else {
> + res = -ENOENT;
> + goto out;
> + }
The second branch suggests that we should be returning errno values
upon failure. At least one code path in lxcProcReadMeminfo instead
returns simply -1. This code should all use normal libvirt error
reporting APIs and return -1 on error. Then right at the end of this
method, if res == -1, then use virGetLastError() to fetch any
virErrorPtr object. If the code == VIR_ERR_SYSTEM_ERROR then you
can get the errno value from the 'int1' field in virErrorPtr.
Otherwise you can just use EIO
> +
> + if (res < 0) {
> + if((res = lxcProcHostRead(hostpath, buf, size, offset)) < 0)
> + virReportSystemError(errno, "%s",
> + _("failed to show host's meminfo"));
> + }
> +
> +out:
> + VIR_FREE(hostpath);
> + return res;
> }
>
> static struct fuse_operations lxcProcOper = {
> diff --git a/src/lxc/lxc_fuse.h b/src/lxc/lxc_fuse.h
> index d60c238..7db534b 100644
> --- a/src/lxc/lxc_fuse.h
> +++ b/src/lxc/lxc_fuse.h
> @@ -35,6 +35,20 @@
> #include "util.h"
> #include "memory.h"
>
> +enum {
> + MEMTOTAL,
> + MEMUSAGE,
> + CACHED,
> + ACTIVE_ANON,
> + INACTIVE_ANON,
> + ACTIVE_FILE,
> + INACTIVE_FILE,
> + UNEVICTABLE,
> + SWAPTOTAL,
> + SWAPUSAGE,
> + MEMMAX,
> +};
Please use a prefix on any constants, ie VIR_LXC_FUSE_MEMTOTAL
Daniel
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