[libvirt] [PATCH v4 5/6] make /proc/meminfo isolate with host through fuse

Gao feng gaofeng at cn.fujitsu.com
Tue Oct 23 08:38:35 UTC 2012


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 |  139 +++++++++++++++++++++++++++++++++
 src/lxc/lxc_cgroup.h |    1 +
 src/lxc/lxc_fuse.c   |  209 +++++++++++++++++++++++++++++++++++++++++++++++--
 src/lxc/lxc_fuse.h   |   14 ++++
 4 files changed, 354 insertions(+), 9 deletions(-)

diff --git a/src/lxc/lxc_cgroup.c b/src/lxc/lxc_cgroup.c
index bdfaa54..1e3a318 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;
diff --git a/src/lxc/lxc_cgroup.h b/src/lxc/lxc_cgroup.h
index 6fc68df..c549d6c 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 164897e..0deaf57 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 *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;
 }
 
@@ -61,23 +84,191 @@ static int lxcProcReaddir(const char *path, void *buf,
 
     filler(buf, ".", NULL, 0);
     filler(buf, "..", NULL, 0);
+    filler(buf, fuse_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, fuse_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)
+{
+    int fd;
+    int res;
+
+    fd = open(path, O_RDONLY);
+    if (fd == -1)
+        return -errno;
+
+    if ((res = pread(fd, buf, size, offset)) < 0)
+        res = -errno;
+
+    VIR_FORCE_CLOSE(fd);
+    return res;
+}
+
+static int lxcProcReadMeminfo(char *hostpath, virDomainDefPtr def,
+                              char *buf, size_t size, off_t offset)
 {
-    return -ENOENT;
+    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,
-                       char *buf ATTRIBUTE_UNUSED,
-                       size_t size ATTRIBUTE_UNUSED,
-                       off_t offset ATTRIBUTE_UNUSED,
+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 = -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;
 }
 
 static struct fuse_operations lxcProcOper = {
diff --git a/src/lxc/lxc_fuse.h b/src/lxc/lxc_fuse.h
index d188190..0a036f8 100644
--- a/src/lxc/lxc_fuse.h
+++ b/src/lxc/lxc_fuse.h
@@ -35,6 +35,20 @@
 #include "util.h"
 #include "memory.h"
 
+enum {
+    VIR_LXC_FUSE_MEMTOTAL,
+    VIR_LXC_FUSE_MEMUSAGE,
+    VIR_LXC_FUSE_CACHED,
+    VIR_LXC_FUSE_ACTIVE_ANON,
+    VIR_LXC_FUSE_INACTIVE_ANON,
+    VIR_LXC_FUSE_ACTIVE_FILE,
+    VIR_LXC_FUSE_INACTIVE_FILE,
+    VIR_LXC_FUSE_UNEVICTABLE,
+    VIR_LXC_FUSE_SWAPTOTAL,
+    VIR_LXC_FUSE_SWAPUSAGE,
+    VIR_LXC_FUSE_MEMMAX,
+};
+
 extern void lxcRegisterFuse(void *opaque);
 extern void lxcUnregisterFuse(virDomainDefPtr def);
 #endif
-- 
1.7.7.6




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