fix swap values with nested cgroups

the memory limit was already correctly set by looking at the
whole cgroup hierarchy and using the minimum value, refactor
that code to support arbitrary files in the memory cgroup
and reuse it for the memsw limit as well.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

diff --git a/bindings.c b/bindings.c
index 93c5aaabe6282babcc0b7f206fc10bd82e145e7c..3516be613ed012d7745035138756ef168cf92e68 100644 (file)
--- a/bindings.c
+++ b/bindings.c
@@ -3046,12 +3046,12 @@ static int read_file(const char *path, char *buf, size_t size,
  * FUSE ops for /proc
  */
 
-static unsigned long get_memlimit(const char *cgroup)
+static unsigned long get_memlimit(const char *cgroup, const char *file)
 {
        char *memlimit_str = NULL;
        unsigned long memlimit = -1;
 
-       if (cgfs_get_value("memory", cgroup, "memory.limit_in_bytes", &memlimit_str))
+       if (cgfs_get_value("memory", cgroup, file, &memlimit_str))
                memlimit = strtoul(memlimit_str, NULL, 10);
 
        free(memlimit_str);
@@ -3059,16 +3059,16 @@ static unsigned long get_memlimit(const char *cgroup)
        return memlimit;
 }
 
-static unsigned long get_min_memlimit(const char *cgroup)
+static unsigned long get_min_memlimit(const char *cgroup, const char *file)
 {
        char *copy = strdupa(cgroup);
        unsigned long memlimit = 0, retlimit;
 
-       retlimit = get_memlimit(copy);
+       retlimit = get_memlimit(copy, file);
 
        while (strcmp(copy, "/") != 0) {
                copy = dirname(copy);
-               memlimit = get_memlimit(copy);
+               memlimit = get_memlimit(copy, file);
                if (memlimit != -1 && memlimit < retlimit)
                        retlimit = memlimit;
        };
@@ -3083,8 +3083,7 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
        struct file_info *d = (struct file_info *)fi->fh;
        char *cg;
        char *memusage_str = NULL, *memstat_str = NULL,
-               *memswlimit_str = NULL, *memswusage_str = NULL,
-               *memswlimit_default_str = NULL, *memswusage_default_str = NULL;
+               *memswlimit_str = NULL, *memswusage_str = NULL;
        unsigned long memlimit = 0, memusage = 0, memswlimit = 0, memswusage = 0,
                cached = 0, hosttotal = 0, active_anon = 0, inactive_anon = 0,
                active_file = 0, inactive_file = 0, unevictable = 0;
@@ -3113,7 +3112,7 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
                return read_file("/proc/meminfo", buf, size, d);
        prune_init_slice(cg);
 
-       memlimit = get_min_memlimit(cg);
+       memlimit = get_min_memlimit(cg, "memory.limit_in_bytes");
        if (!cgfs_get_value("memory", cg, "memory.usage_in_bytes", &memusage_str))
                goto err;
        if (!cgfs_get_value("memory", cg, "memory.stat", &memstat_str))
@@ -3124,20 +3123,9 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
        if(cgfs_get_value("memory", cg, "memory.memsw.limit_in_bytes", &memswlimit_str) &&
                cgfs_get_value("memory", cg, "memory.memsw.usage_in_bytes", &memswusage_str))
        {
-               /* If swapaccounting is turned on, then default value is assumed to be that of cgroup / */
-               if (!cgfs_get_value("memory", "/", "memory.memsw.limit_in_bytes", &memswlimit_default_str))
-                       goto err;
-               if (!cgfs_get_value("memory", "/", "memory.memsw.usage_in_bytes", &memswusage_default_str))
-                       goto err;
-
-               memswlimit = strtoul(memswlimit_str, NULL, 10);
+               memswlimit = get_min_memlimit(cg, "memory.memsw.limit_in_bytes");
                memswusage = strtoul(memswusage_str, NULL, 10);
 
-               if (!strcmp(memswlimit_str, memswlimit_default_str))
-                       memswlimit = 0;
-               if (!strcmp(memswusage_str, memswusage_default_str))
-                       memswusage = 0;
-
                memswlimit = memswlimit / 1024;
                memswusage = memswusage / 1024;
        }
@@ -3257,8 +3245,6 @@ err:
        free(memswlimit_str);
        free(memswusage_str);
        free(memstat_str);
-       free(memswlimit_default_str);
-       free(memswusage_default_str);
        return rv;
 }
 
@@ -3859,8 +3845,7 @@ static int proc_swaps_read(char *buf, size_t size, off_t offset,
        struct fuse_context *fc = fuse_get_context();
        struct file_info *d = (struct file_info *)fi->fh;
        char *cg = NULL;
-       char *memswlimit_str = NULL, *memlimit_str = NULL, *memusage_str = NULL, *memswusage_str = NULL,
-             *memswlimit_default_str = NULL, *memswusage_default_str = NULL;
+       char *memswlimit_str = NULL, *memlimit_str = NULL, *memusage_str = NULL, *memswusage_str = NULL;
        unsigned long memswlimit = 0, memlimit = 0, memusage = 0, memswusage = 0, swap_total = 0, swap_free = 0;
        ssize_t total_len = 0, rv = 0;
        ssize_t l = 0;
@@ -3885,32 +3870,19 @@ static int proc_swaps_read(char *buf, size_t size, off_t offset,
                return read_file("/proc/swaps", buf, size, d);
        prune_init_slice(cg);
 
-       if (!cgfs_get_value("memory", cg, "memory.limit_in_bytes", &memlimit_str))
-               goto err;
+       memlimit = get_min_memlimit(cg, "memory.limit_in_bytes");
 
        if (!cgfs_get_value("memory", cg, "memory.usage_in_bytes", &memusage_str))
                goto err;
 
-       memlimit = strtoul(memlimit_str, NULL, 10);
        memusage = strtoul(memusage_str, NULL, 10);
 
        if (cgfs_get_value("memory", cg, "memory.memsw.usage_in_bytes", &memswusage_str) &&
            cgfs_get_value("memory", cg, "memory.memsw.limit_in_bytes", &memswlimit_str)) {
 
-                /* If swap accounting is turned on, then default value is assumed to be that of cgroup / */
-                if (!cgfs_get_value("memory", "/", "memory.memsw.limit_in_bytes", &memswlimit_default_str))
-                    goto err;
-                if (!cgfs_get_value("memory", "/", "memory.memsw.usage_in_bytes", &memswusage_default_str))
-                    goto err;
-
-               memswlimit = strtoul(memswlimit_str, NULL, 10);
+               memswlimit = get_min_memlimit(cg, "memory.memsw.limit_in_bytes");
                memswusage = strtoul(memswusage_str, NULL, 10);
 
-                if (!strcmp(memswlimit_str, memswlimit_default_str))
-                    memswlimit = 0;
-                if (!strcmp(memswusage_str, memswusage_default_str))
-                    memswusage = 0;
-
                swap_total = (memswlimit - memlimit) / 1024;
                swap_free = (memswusage - memusage) / 1024;
        }
@@ -3964,8 +3936,6 @@ err:
        free(memlimit_str);
        free(memusage_str);
        free(memswusage_str);
-       free(memswusage_default_str);
-       free(memswlimit_default_str);
        return rv;
 }