[libvirt] [RFC] [PATCH v3 5/6] make /proc/meminfo isolate with host through fuse

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(a)cn.fujitsu.com&gt; --- 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; + } + + 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, +}; + extern void lxcRegisterFuse(void *DomainDef); extern void lxcUnregisterFuse(virDomainDefPtr def); #endif -- 1.7.7.6