Re: [libvirt] [PATCH v5 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 | 139 +++++++++++++++++++++++++++++++++++ src/lxc/lxc_cgroup.h | 2 +- src/lxc/lxc_fuse.c | 198 +++++++++++++++++++++++++++++++++++++++++++++++++- src/lxc/lxc_fuse.h | 14 ++++ 4 files changed, 349 insertions(+), 4 deletions(-) diff --git a/src/lxc/lxc_cgroup.c b/src/lxc/lxc_cgroup.c index 9a5ba1a..543a7fe 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" @@ -137,6 +139,143 @@ cleanup: return ret; } +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 = -errno; + 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 (virStrToLong_ull(value + 1, NULL, 10, &stat_value) < 0) { + ret = -EINVAL; + goto out; + } + if (STREQ(line, "cache")) + meminfo[VIR_LXC_FUSE_CACHED] = stat_value >> 10; + else if (STREQ(line, "inactive_anon")) + meminfo[VIR_LXC_FUSE_INACTIVE_ANON] = stat_value >> 10; + else if (STREQ(line, "active_anon")) + meminfo[VIR_LXC_FUSE_ACTIVE_ANON] = stat_value >> 10; + else if (STREQ(line, "inactive_file")) + meminfo[VIR_LXC_FUSE_INACTIVE_FILE] = stat_value >> 10; + else if (STREQ(line, "active_file")) + meminfo[VIR_LXC_FUSE_ACTIVE_FILE] = stat_value >> 10; + else if (STREQ(line, "unevictable")) + meminfo[VIR_LXC_FUSE_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[VIR_LXC_FUSE_MEMTOTAL]); + if (ret < 0) { + virReportSystemError(-ret, "%s", + _("Unable to get memory cgroup total")); + goto out; + } + + ret = virLXCCgroupGetMemUsage(cgroup, &meminfo[VIR_LXC_FUSE_MEMUSAGE]); + if (ret < 0) { + virReportSystemError(-ret, "%s", + _("Unable to get memory cgroup stat usage")); + goto out; + } + + virLXCCgroupGetMemSwapTotal(cgroup, &meminfo[VIR_LXC_FUSE_SWAPTOTAL]); + virLXCCgroupGetMemSwapUsage(cgroup, &meminfo[VIR_LXC_FUSE_SWAPUSAGE]); + + ret = 0; +out:

+ virCgroupFree(&cgroup); + + return ret; +} typedef struct _virLXCCgroupDevicePolicy virLXCCgroupDevicePolicy; typedef virLXCCgroupDevicePolicy *virLXCCgroupDevicePolicyPtr; +static const char *fuse_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 (virAsprintf(&mempath, "/proc/%s", path) < 0) { + virReportOOMError(); + return -errno; + } + + res = 0; if (STREQ(path, "/")) { stbuf->st_mode = S_IFDIR | 0755; stbuf->st_nlink = 2; + } else if (STREQ(path, fuse_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; }

@@ -70,7 +94,153 @@ static int lxcProcReaddir(const char *path, void *buf, static int lxcProcOpen(const char *path ATTRIBUTE_UNUSED, struct fuse_file_info *fi ATTRIBUTE_UNUSED)

{ - return -ENOENT; + if (!STREQ(path, fuse_meminfo_path)) + return -ENOENT; + + if ((fi->flags & 3) != O_RDONLY) + return -EACCES; + + return 0; +}

+static int lxcProcReadMeminfo(char *hostpath, virDomainDefPtr def, + char *buf, size_t size, off_t offset) +{ + int copied = 0; + int res; + FILE *fd = NULL; + char line[1024]; + unsigned long long meminfo[VIR_LXC_FUSE_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 (virAsprintf(&new_line, "MemTotal: %8llu KB\n", + meminfo[VIR_LXC_FUSE_MEMTOTAL]) < 0) { + goto out_oom; + } + } else if (STREQ(line, "MemFree") && + (def->mem.hard_limit || def->mem.max_balloon)) { + if (virAsprintf(&new_line, "MemFree: %8llu KB\n", + (meminfo[VIR_LXC_FUSE_MEMTOTAL] - meminfo[VIR_LXC_FUSE_MEMUSAGE])) < 0) { + goto out_oom; + } + } else if (STREQ(line, "Buffers")) { + if (virAsprintf(&new_line, "Buffers: %8d KB\n", 0) < 0) { + goto out_oom; + } + } else if (STREQ(line, "Cached")) { + if (virAsprintf(&new_line, "Cached: %8llu KB\n", + meminfo[VIR_LXC_FUSE_CACHED]) < 0) { + goto out_oom; + } + } else if (STREQ(line, "Active")) { + if (virAsprintf(&new_line, "Active: %8llu KB\n", + (meminfo[VIR_LXC_FUSE_ACTIVE_ANON] + meminfo[VIR_LXC_FUSE_ACTIVE_FILE])) < 0) { + goto out_oom; + } + } else if (STREQ(line, "Inactive")) { + if (virAsprintf(&new_line, "Inactive: %8llu KB\n", + (meminfo[VIR_LXC_FUSE_INACTIVE_ANON] + meminfo[VIR_LXC_FUSE_INACTIVE_FILE])) < 0) { + goto out_oom; + } + } else if (STREQ(line, "Active(anon)")) { + if (virAsprintf(&new_line, "Active(anon): %8llu KB\n", + meminfo[VIR_LXC_FUSE_ACTIVE_ANON]) < 0) { + goto out_oom; + } + } else if (STREQ(line, "Inactive(anon)")) { + if (virAsprintf(&new_line, "Inactive(anon): %8llu KB\n", + meminfo[VIR_LXC_FUSE_INACTIVE_ANON]) < 0) { + goto out_oom; + } + } else if (STREQ(line, "Active(file)")) { + if (virAsprintf(&new_line, "Active(file): %8llu KB\n", + meminfo[VIR_LXC_FUSE_ACTIVE_FILE]) < 0) { + goto out_oom; + } + } else if (STREQ(line, "Inactive(file)")) { + if (virAsprintf(&new_line, "Inactive(file): %8llu KB\n", + meminfo[VIR_LXC_FUSE_INACTIVE_FILE]) < 0) { + goto out_oom; + } + } else if (STREQ(line, "Unevictable")) { + if (virAsprintf(&new_line, "Unevictable: %8llu KB\n", + meminfo[VIR_LXC_FUSE_UNEVICTABLE]) < 0) { + goto out_oom; + } + } else if (STREQ(line, "SwapTotal") && def->mem.swap_hard_limit) { + if (virAsprintf(&new_line, "SwapTotal: %8llu KB\n", + (meminfo[VIR_LXC_FUSE_SWAPTOTAL] - meminfo[VIR_LXC_FUSE_MEMTOTAL])) < 0) { + goto out_oom; + } + } else if (STREQ(line, "SwapFree") && def->mem.swap_hard_limit) { + if (virAsprintf(&new_line, "SwapFree: %8llu KB\n", + (meminfo[VIR_LXC_FUSE_SWAPTOTAL] - meminfo[VIR_LXC_FUSE_MEMTOTAL] - + meminfo[VIR_LXC_FUSE_SWAPUSAGE] + meminfo[VIR_LXC_FUSE_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(); + res = -errno; + goto out; }

static int lxcProcRead(const char *path ATTRIBUTE_UNUSED, @@ -79,7 +249,29 @@ static int lxcProcRead(const char *path ATTRIBUTE_UNUSED, off_t offset ATTRIBUTE_UNUSED, struct fuse_file_info *fi ATTRIBUTE_UNUSED) { - return -ENOENT; + int res = -ENOENT; + char *hostpath = NULL; + struct fuse_context *context = NULL; + virDomainDefPtr def = NULL; + + if (virAsprintf(&hostpath, "/proc/%s", path) < 0) { + virReportOOMError(); + return -errno; + } + + context = fuse_get_context(); + def = (virDomainDefPtr)context->private_data; + + if (STREQ(path, fuse_meminfo_path)) { + if (((res = lxcProcReadMeminfo(hostpath, def, buf, size, offset)) < 0) && + ((res = lxcProcHostRead(hostpath, buf, size, offset)) < 0)) + goto out; + } + +out:

+ VIR_FREE(hostpath); + return res; + }