proc_fuse: improve swap calculation a little

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/proc_fuse.c b/src/proc_fuse.c
index 44bed243c010d5de27f025059598946ff772edde..3653aa3b77dcb5feed4cd5e544afd181f8515db6 100644 (file)
--- a/src/proc_fuse.c
+++ b/src/proc_fuse.c
@@ -247,6 +247,8 @@ static int proc_swaps_read(char *buf, size_t size, off_t offset,
        __do_free char *cg = NULL, *memswlimit_str = NULL, *memusage_str = NULL,
                       *memswusage_str = NULL;
        struct fuse_context *fc = fuse_get_context();
+       struct lxcfs_opts *opts = (struct lxcfs_opts *)fuse_get_context()->private_data;
+       bool wants_swap = opts && !opts->swap_off;
        struct file_info *d = INTTYPE_TO_PTR(fi->fh);
        uint64_t memswlimit = 0, memlimit = 0, memusage = 0, memswusage = 0,
                 swap_total = 0, swap_free = 0;
@@ -289,17 +291,19 @@ static int proc_swaps_read(char *buf, size_t size, off_t offset,
        if (safe_uint64(memusage_str, &memusage, 10) < 0)
                lxcfs_error("Failed to convert memusage %s", memusage_str);
 
-       ret = cgroup_ops->get_memory_swap_max(cgroup_ops, cg, &memswlimit_str);
-       if (ret >= 0)
-               ret = cgroup_ops->get_memory_swap_current(cgroup_ops, cg, &memswusage_str);
-       if (ret >= 0) {
-               memswlimit = get_min_memlimit(cg, true);
+       if (wants_swap) {
+               ret = cgroup_ops->get_memory_swap_max(cgroup_ops, cg, &memswlimit_str);
+               if (ret >= 0)
+                       ret = cgroup_ops->get_memory_swap_current(cgroup_ops, cg, &memswusage_str);
+               if (ret >= 0) {
+                       memswlimit = get_min_memlimit(cg, true);
 
-               if (safe_uint64(memswusage_str, &memswusage, 10) < 0)
-                       lxcfs_error("Failed to convert memswusage %s", memswusage_str);
+                       if (safe_uint64(memswusage_str, &memswusage, 10) < 0)
+                               lxcfs_error("Failed to convert memswusage %s", memswusage_str);
 
-               swap_total = (memswlimit - memlimit) / 1024;
-               swap_free = (memswusage - memusage) / 1024;
+                       swap_total = (memswlimit - memlimit) / 1024;
+                       swap_free = (memswusage - memusage) / 1024;
+               }
        }
 
        total_len = snprintf(d->buf, d->size, "Filename\t\t\t\tType\t\tSize\tUsed\tPriority\n");
@@ -1013,6 +1017,7 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
        __do_fclose FILE *f = NULL;
        struct fuse_context *fc = fuse_get_context();
        struct lxcfs_opts *opts = (struct lxcfs_opts *)fuse_get_context()->private_data;
+       bool wants_swap = opts && !opts->swap_off;
        struct file_info *d = INTTYPE_TO_PTR(fi->fh);
        uint64_t memlimit = 0, memusage = 0, memswlimit = 0, memswusage = 0,
                 hosttotal = 0, swtotal = 0;
@@ -1061,17 +1066,19 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
         * Following values are allowed to fail, because swapaccount might be
         * turned off for current kernel.
         */
-       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);
-               memswlimit = memswlimit / 1024;
-
-               if (safe_uint64(memswusage_str, &memswusage, 10) < 0)
-                       lxcfs_error("Failed to convert memswusage %s", memswusage_str);
-               memswusage = memswusage / 1024;
-               swtotal = memswlimit;
+       if (wants_swap) {
+               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);
+                       memswlimit = memswlimit / 1024;
+
+                       if (safe_uint64(memswusage_str, &memswusage, 10) < 0)
+                               lxcfs_error("Failed to convert memswusage %s", memswusage_str);
+                       memswusage = memswusage / 1024;
+                       swtotal = memswlimit;
+               }
        }
 
        if (safe_uint64(memusage_str, &memusage, 10) < 0)
@@ -1103,7 +1110,7 @@ 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) {
+               } else if (startswith(line, "SwapTotal:") && memswlimit > 0 && wants_swap) {
                        uint64_t hostswtotal = 0;
 
                        sscanf(line + STRLITERALLEN("SwapTotal:"), "%" PRIu64, &hostswtotal);
@@ -1114,11 +1121,10 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
 
                        snprintf(lbuf, 100, "SwapTotal:      %8" PRIu64 " kB\n", swtotal);
                        printme = lbuf;
-               } else if (startswith(line, "SwapTotal:") && opts && opts->swap_off == true) {
+               } else if (startswith(line, "SwapTotal:") && !wants_swap) {
                        snprintf(lbuf, 100, "SwapTotal:      %8" PRIu64 " kB\n", (uint64_t)0);
                        printme = lbuf;
-               } else if (startswith(line, "SwapFree:") && memswlimit > 0 &&
-                          opts && opts->swap_off == false) {
+               } else if (startswith(line, "SwapFree:") && memswlimit > 0 && wants_swap) {
                        uint64_t swfree = 0;
                        uint64_t swusage = 0;
 
@@ -1127,7 +1133,7 @@ static int proc_meminfo_read(char *buf, size_t size, off_t offset,
 
                        snprintf(lbuf, 100, "SwapFree:       %8" PRIu64 " kB\n", swfree);
                        printme = lbuf;
-               } else if (startswith(line, "SwapFree:") && opts && opts->swap_off == true) {
+               } else if (startswith(line, "SwapFree:") && !wants_swap) {
                        snprintf(lbuf, 100, "SwapFree:       %8" PRIu64 " kB\n", (uint64_t)0);
                        printme = lbuf;
                } else if (startswith(line, "Slab:")) {