chmem: add a new --sysroot command line option

This new option allows an administrator to configure memory
on a Linux instance other than the one on which chmem(1) is
executed. Additionally, it facilitates regression testing
with sysfs dumps.

Signed-off-by: Christian Goeschel Ndjomouo <cgoesc2@wgu.edu>

diff --git a/bash-completion/chmem b/bash-completion/chmem
index f10646677e12f9b5253fd24231a31892e3a6e620..f33f8ab163dbcbb834853c6876d63d2a760f2b2d 100644 (file)
--- a/bash-completion/chmem
+++ b/bash-completion/chmem
@@ -5,6 +5,10 @@ _chmem_module()
        cur="${COMP_WORDS[COMP_CWORD]}"
        prev="${COMP_WORDS[COMP_CWORD-1]}"
        case $prev in
+               '-s'|'--sysroot')
+                       COMPREPLY=( $(compgen -d -- $cur) )
+                       return 0
+                       ;;
                '-h'|'--help'|'-V'|'--version')
                        return 0
                        ;;
@@ -20,6 +24,7 @@ _chmem_module()
                                --blocks
                                --verbose
                                --zone
+                               --sysroot
                                --help
                                --version
                        "

diff --git a/sys-utils/chmem.8.adoc b/sys-utils/chmem.8.adoc
index f695bb96e8ed5eff334c4112505078b5f293c491..a08227a244cc977a1fc5db099d83f128b62ac347 100644 (file)
--- a/sys-utils/chmem.8.adoc
+++ b/sys-utils/chmem.8.adoc
@@ -68,6 +68,9 @@ Set the specified _RANGE_, _SIZE_, or _BLOCKRANGE_ of memory to be deconfigured.
 *-m*, *--memmap-on-memory*::
 Select memmap-on-memory for the specified _RANGE_, _SIZE_, or _BLOCKRANGE_ of memory. This option is valid only with *--configure*.
 
+*-s*, *--sysroot* _directory_::
+Configure memory blocks for a Linux instance other than the instance from which the *chmem* command is issued. The specified _directory_ is the system root of the Linux instance to be configured.
+
 *-z*, *--zone*::
 Select the memory _ZONE_ where to set the specified _RANGE_, _SIZE_, or _BLOCKRANGE_ of memory online or offline. By default, memory will be set online to the zone Movable, if possible.
 

diff --git a/sys-utils/chmem.c b/sys-utils/chmem.c
index 925a7fb9590ac8235f9b33ec5add71fc2bdc7b0c..00a5f863b87d48a77130acf5047b714bd40bae80 100644 (file)
--- a/sys-utils/chmem.c
+++ b/sys-utils/chmem.c
@@ -419,10 +419,9 @@ static int chmem_onoff_range(struct chmem_desc *desc, int enable, int zone_id)
                idxtostr(desc, index, str, sizeof(str));
                if (ul_path_readf_buffer(desc->sysmem, line, sizeof(line), "%s/state", name) > 0) {
                        if (strncmp(onoff, line, 6) == 0) {
-                               if (desc->verbose && enable)
-                                       fprintf(stdout, _("%s already enabled\n"), str);
-                               else if (desc->verbose && !enable)
-                                       fprintf(stdout, _("%s already disabled\n"), str);
+                               if (desc->verbose)
+                                       printf(enable ? _("%s already enabled\n") :
+                                                       _("%s already disabled\n"), str);
                                todo--;
                                continue;
                        }
@@ -463,15 +462,11 @@ static int chmem_onoff_range(struct chmem_desc *desc, int enable, int zone_id)
 
                rc = ul_path_writef_string(desc->sysmem, onoff, "%s/state", name);
                if (rc != 0) {
-                       if (enable)
-                               warn(_("%s enable failed"), str);
-                       else
-                               warn(_("%s disable failed"), str);
+                       warn(enable ? _("%s enable failed") :
+                                       _("%s disable failed"), str);
                } else if (desc->verbose) {
-                       if (enable)
-                               fprintf(stdout, _("%s enabled\n"), str);
-                       else
-                               fprintf(stdout, _("%s disabled\n"), str);
+                       printf(enable ? _("%s enabled\n") :
+                                       _("%s disabled\n"), str);
                }
                if (!rc && !enable && desc->have_memconfig) {
                        /* Deconfigure memory block */
@@ -494,9 +489,13 @@ static int filter(const struct dirent *de)
 
 static void read_conf(struct chmem_desc *desc)
 {
+       char absdir[PATH_MAX];
+
        if (!desc->have_memconfig)
                return;
-       desc->memconfig_ndirs = scandir(_PATH_SYS_MEMCONFIG, &desc->memconfig_dirs,
+
+       ul_path_get_abspath(desc->sysmemconfig, absdir, sizeof(absdir), NULL);
+       desc->memconfig_ndirs = scandir(absdir, &desc->memconfig_dirs,
                                        filter, versionsort);
        if (desc->memconfig_ndirs <= 0)
                err(EXIT_FAILURE, _("Failed to read %s"), _PATH_SYS_MEMCONFIG);
@@ -505,8 +504,11 @@ static void read_conf(struct chmem_desc *desc)
 static void read_info(struct chmem_desc *desc)
 {
        char line[128];
+       char absdir[PATH_MAX];
 
-       desc->ndirs = scandir(_PATH_SYS_MEMORY, &desc->dirs, filter, versionsort);
+       ul_path_get_abspath(desc->sysmem, absdir, sizeof(absdir), NULL);
+
+       desc->ndirs = scandir(absdir, &desc->dirs, filter, versionsort);
        if (desc->ndirs <= 0)
                goto fail;
        if (ul_path_read_buffer(desc->sysmem, line, sizeof(line), "block_size_bytes") < 0)
@@ -593,15 +595,16 @@ static void __attribute__((__noreturn__)) usage(void)
        fputs(_("Set a particular size or range of memory online or offline.\n"), out);
 
        fputs(USAGE_OPTIONS, out);
-       fputs(_(" -e, --enable       enable memory\n"), out);
-       fputs(_(" -d, --disable      disable memory\n"), out);
-       fputs(_(" -b, --blocks       use memory blocks\n"), out);
-       fputs(_(" -z, --zone <name>  select memory zone (see below)\n"), out);
-       fputs(_(" -c, --configure    configure range\n"), out);
-       fputs(_(" -g, --deconfigure  deconfigure range\n"), out);
-       fputs(_(" -m, --memmap-on-memory select memmap-on-memory\n"), out);
-       fputs(_(" -v, --verbose      verbose output\n"), out);
-       fprintf(out, USAGE_HELP_OPTIONS(20));
+       fputs(_(" -e, --enable             enable memory\n"), out);
+       fputs(_(" -d, --disable            disable memory\n"), out);
+       fputs(_(" -b, --blocks             use memory blocks\n"), out);
+       fputs(_(" -z, --zone <name>        select memory zone (see below)\n"), out);
+       fputs(_(" -c, --configure          configure range\n"), out);
+       fputs(_(" -g, --deconfigure        deconfigure range\n"), out);
+       fputs(_(" -m, --memmap-on-memory   select memmap-on-memory\n"), out);
+       fputs(_(" -s, --sysroot <dir>      use the specified directory as system root\n"), out);
+       fputs(_(" -v, --verbose            verbose output\n"), out);
+       fprintf(out, USAGE_HELP_OPTIONS(26));
 
        fputs(_("\nSupported zones:\n"), out);
        for (i = 0; i < ARRAY_SIZE(zone_names); i++)
@@ -660,9 +663,11 @@ static int chmem_size(struct chmem_desc *desc, int cmd, int zone_id)
 
 int main(int argc, char **argv)
 {
-       struct chmem_desc _desc = { 0 }, *desc = &_desc;
+       struct chmem_desc _desc = {
+               .memmap_on_memory = -1,
+       }, *desc = &_desc;
        int cmd = CMD_NONE, zone_id = -1;
-       char *zone = NULL;
+       char *zone = NULL, *sysroot = NULL;
        int c, rc;
 
        static const struct option longopts[] = {
@@ -676,6 +681,7 @@ int main(int argc, char **argv)
                {"configure",   no_argument,            NULL, 'c'},
                {"deconfigure", no_argument,            NULL, 'g'},
                {"memmap-on-memory", required_argument, NULL, 'm'},
+               {"sysroot", required_argument,  NULL, 's'},
                {NULL,          0,                      NULL, 0}
        };
 
@@ -691,19 +697,7 @@ int main(int argc, char **argv)
        textdomain(PACKAGE);
        close_stdout_atexit();
 
-       ul_path_init_debug();
-       desc->memmap_on_memory = -1;
-       desc->sysmem = ul_new_path(_PATH_SYS_MEMORY);
-       if (!desc->sysmem)
-               err(EXIT_FAILURE, _("failed to initialize %s handler"), _PATH_SYS_MEMORY);
-       desc->sysmemconfig = ul_new_path(_PATH_SYS_MEMCONFIG);
-       if (!desc->sysmemconfig)
-               err(EXIT_FAILURE, _("failed to initialize %s handler"), _PATH_SYS_MEMCONFIG);
-       if (ul_path_access(desc->sysmemconfig, F_OK, "memory0") == 0)
-               desc->have_memconfig = 1;
-       read_info(desc);
-
-       while ((c = getopt_long(argc, argv, "bcdeghm:vVz:", longopts, NULL)) != -1) {
+       while ((c = getopt_long(argc, argv, "bcdeghm:s:vVz:", longopts, NULL)) != -1) {
 
                err_exclusive_options(c, longopts, excl, excl_st);
 
@@ -732,6 +726,9 @@ int main(int argc, char **argv)
                case 'm':
                        desc->memmap_on_memory = atoi(optarg);
                        break;
+               case 's':
+                       sysroot = optarg;
+                       break;
                case 'h':
                        usage();
                case 'V':
@@ -746,8 +743,26 @@ int main(int argc, char **argv)
                errtryhelp(EXIT_FAILURE);
        }
 
-       parse_parameter(desc, argv[optind]);
+       ul_path_init_debug();
+
+       desc->sysmem = ul_new_path(_PATH_SYS_MEMORY);
+       if (!desc->sysmem)
+               err(EXIT_FAILURE, _("failed to initialize %s handler"), _PATH_SYS_MEMORY);
+       if (sysroot && ul_path_set_prefix(desc->sysmem, sysroot) != 0)
+               err(EXIT_FAILURE, _("invalid argument to --sysroot"));
+       if (!ul_path_is_accessible(desc->sysmem))
+               err(EXIT_FAILURE, _("cannot open %s"), _PATH_SYS_MEMORY);
 
+       desc->sysmemconfig = ul_new_path(_PATH_SYS_MEMCONFIG);
+       if (!desc->sysmemconfig)
+               err(EXIT_FAILURE, _("failed to initialize %s handler"), _PATH_SYS_MEMCONFIG);
+       if (sysroot && ul_path_set_prefix(desc->sysmemconfig, sysroot) != 0)
+               err(EXIT_FAILURE, _("invalid argument to --sysroot"));
+       if (ul_path_access(desc->sysmemconfig, F_OK, "memory0") == 0)
+               desc->have_memconfig = 1;
+
+       read_info(desc);
+       parse_parameter(desc, argv[optind]);
 
        /* The valid_zones sysfs attribute was introduced with kernel 3.18 */
        if (ul_path_access(desc->sysmem, F_OK, "memory0/valid_zones") == 0)