[lxc-devel] [lxcfs/master] proc_fuse: improve /proc/meminfo
brauner on Github
lxc-bot at linuxcontainers.org
Fri Mar 20 09:48:26 UTC 2020
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From 6d025f61da2045ee65c56ff13ee27cb515f39381 Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brauner at ubuntu.com>
Date: Fri, 20 Mar 2020 10:46:40 +0100
Subject: [PATCH] proc_fuse: improve /proc/meminfo
Signed-off-by: Christian Brauner <christian.brauner at ubuntu.com>
---
src/proc_fuse.c | 32 ++++++++++++++++++--------------
src/utils.c | 25 ++++++++++++++++++++++++-
src/utils.h | 1 +
3 files changed, 43 insertions(+), 15 deletions(-)
diff --git a/src/proc_fuse.c b/src/proc_fuse.c
index c3870fb..233d5e0 100644
--- a/src/proc_fuse.c
+++ b/src/proc_fuse.c
@@ -1075,10 +1075,10 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
ret = cgroup_ops->get_memory_current(cgroup_ops, cgroup, &memusage_str);
if (ret < 0)
- return 0;
+ return read_file_fuse("/proc/meminfo", buf, size, d);
if (!cgroup_parse_memory_stat(cgroup, &mstat))
- return 0;
+ return read_file_fuse("/proc/meminfo", buf, size, d);
/*
* Following values are allowed to fail, because swapaccount might be
@@ -1087,20 +1087,23 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
ret = cgroup_ops->get_memory_swap_max(cgroup_ops, cgroup, &memswlimit_str);
if (ret >= 0)
ret = cgroup_ops->get_memory_swap_current(cgroup_ops, cgroup, &memswusage_str);
- if (ret >= 0) {
- memswlimit = get_min_memlimit(cgroup, true);
- memswusage = strtoull(memswusage_str, NULL, 10);
- memswlimit = memswlimit / 1024;
- memswusage = memswusage / 1024;
- }
+ if (ret < 0)
+ return read_file_fuse("/proc/meminfo", buf, size, d);
- memusage = strtoull(memusage_str, NULL, 10);
+ memswlimit = get_min_memlimit(cgroup, true);
+ memswlimit = memswlimit / 1024;
+ if (safe_uint64(memswusage_str, &memswusage, 10) < 0)
+ memswusage = 0;
+ memswusage = memswusage / 1024;
+
+ if (safe_uint64(memusage_str, &memusage, 10) < 0)
+ memusage = 0;
memlimit /= 1024;
memusage /= 1024;
f = fopen_cached("/proc/meminfo", "re", &fopen_cache);
if (!f)
- return 0;
+ return read_file_fuse("/proc/meminfo", buf, size, d);
while (getline(&line, &linelen, f) != -1) {
ssize_t l;
@@ -1119,10 +1122,11 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
} else if (startswith(line, "MemAvailable:")) {
snprintf(lbuf, 100, "MemAvailable: %8" PRIu64 " kB\n", memlimit - memusage + mstat.total_cache / 1024);
printme = lbuf;
- } else if (startswith(line, "SwapTotal:") && memswlimit > 0 &&
- opts && opts->swap_off == false) {
- memswlimit -= memlimit;
- snprintf(lbuf, 100, "SwapTotal: %8" PRIu64 " kB\n", memswlimit);
+ } else if (startswith(line, "SwapTotal:") && memswlimit > 0 && opts && opts->swap_off == false) {
+ snprintf(lbuf, 100, "SwapTotal: %8" PRIu64 " kB\n",
+ (memswlimit >= memlimit)
+ ? (memswlimit - memlimit)
+ : 0);
printme = lbuf;
} else if (startswith(line, "SwapTotal:") && opts && opts->swap_off == true) {
snprintf(lbuf, 100, "SwapTotal: %8" PRIu64 " kB\n", (uint64_t)0);
diff --git a/src/utils.c b/src/utils.c
index fe83aef..0be997c 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -10,13 +10,13 @@
#define _FILE_OFFSET_BITS 64
+#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <fuse.h>
#include <inttypes.h>
#include <sched.h>
#include <stdarg.h>
-#include <stdio.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
@@ -520,3 +520,26 @@ ssize_t write_nointr(int fd, const void *buf, size_t count)
return ret;
}
+
+int safe_uint64(const char *numstr, uint64_t *converted, int base)
+{
+ char *err = NULL;
+ uint64_t u;
+
+ while (isspace(*numstr))
+ numstr++;
+
+ if (*numstr == '-')
+ return -EINVAL;
+
+ errno = 0;
+ u = strtoull(numstr, &err, base);
+ if (errno == ERANGE && u == UINT64_MAX)
+ return -ERANGE;
+
+ if (err == numstr || *err != '\0')
+ return -EINVAL;
+
+ *converted = u;
+ return 0;
+}
diff --git a/src/utils.h b/src/utils.h
index 39a2943..29c87dc 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -75,5 +75,6 @@ extern FILE *fopen_cached(const char *path, const char *mode,
void **caller_freed_buffer);
extern FILE *fdopen_cached(int fd, const char *mode, void **caller_freed_buffer);
extern ssize_t write_nointr(int fd, const void *buf, size_t count);
+extern int safe_uint64(const char *numstr, uint64_t *converted, int base);
#endif /* __LXCFS_UTILS_H */
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