mdmon: support scanning for containers

When the given container is '/proc/mdstat' then launch an mdmon instance
per container found in /proc/mdstat.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/mdmon.c b/mdmon.c
index 5aad763892d0fce60de8e46ca5768f3ecd884406..7c5fae5fa8e367054f2ae261226098e54cec8519 100644 (file)
--- a/mdmon.c
+++ b/mdmon.c
@@ -275,20 +275,16 @@ void usage(void)
        exit(2);
 }
 
+int mdmon(char *devname, int devnum, int scan, char *switchroot);
+
 int main(int argc, char *argv[])
 {
-       int mdfd;
-       struct mdinfo *mdi, *di;
-       struct supertype *container;
-       sigset_t set;
-       struct sigaction act;
-       int pfd[2];
-       int status;
-       int ignore;
        char *container_name = NULL;
        char *switchroot = NULL;
        int devnum;
        char *devname;
+       int scan = 0;
+       int status = 0;
 
        switch (argc) {
        case 2:
@@ -306,7 +302,24 @@ int main(int argc, char *argv[])
                usage();
        }
 
-       if (strncmp(container_name, "md", 2) == 0) {
+       if (strcmp(container_name, "/proc/mdstat") == 0) {
+               struct mdstat_ent *mdstat, *e;
+
+               /* launch an mdmon instance for each container found */
+               scan = 1;
+               mdstat = mdstat_read(0, 0);
+               for (e = mdstat; e; e = e->next) {
+                       if (strncmp(e->metadata_version, "external:", 9) == 0 &&
+                           !is_subarray(&e->metadata_version[9])) {
+                               devname = devnum2devname(e->devnum);
+                               status |= mdmon(devname, e->devnum, scan,
+                                               switchroot);
+                       }
+               }
+               free_mdstat(mdstat);
+
+               return status;
+       } else if (strncmp(container_name, "md", 2) == 0) {
                devnum = devname2devnum(container_name);
                devname = devnum2devname(devnum);
                if (strcmp(container_name, devname) != 0)
@@ -328,29 +341,43 @@ int main(int argc, char *argv[])
                        container_name);
                exit(1);
        }
+       return mdmon(devname, devnum, scan, switchroot);
+}
+
+int mdmon(char *devname, int devnum, int scan, char *switchroot)
+{
+       int mdfd;
+       struct mdinfo *mdi, *di;
+       struct supertype *container;
+       sigset_t set;
+       struct sigaction act;
+       int pfd[2];
+       int status;
+       int ignore;
+
        mdfd = open_dev(devnum);
        if (mdfd < 0) {
-               fprintf(stderr, "mdmon: %s: %s\n", container_name,
+               fprintf(stderr, "mdmon: %s: %s\n", devname,
                        strerror(errno));
-               exit(1);
+               return 1;
        }
        if (md_get_version(mdfd) < 0) {
                fprintf(stderr, "mdmon: %s: Not an md device\n",
-                       container_name);
-               exit(1);
+                       devname);
+               return 1;
        }
 
        /* Fork, and have the child tell us when they are ready */
-       if (do_fork()) {
+       if (do_fork() || scan) {
                if (pipe(pfd) != 0) {
                        fprintf(stderr, "mdmon: failed to create pipe\n");
-                       exit(1);
+                       return 1;
                }
                switch(fork()) {
                case -1:
                        fprintf(stderr, "mdmon: failed to fork: %s\n",
                                strerror(errno));
-                       exit(1);
+                       return 1;
                case 0: /* child */
                        close(pfd[0]);
                        break;
@@ -360,7 +387,7 @@ int main(int argc, char *argv[])
                                wait(&status);
                                status = WEXITSTATUS(status);
                        }
-                       exit(status);
+                       return status;
                }
        } else
                pfd[0] = pfd[1] = -1;
@@ -386,20 +413,20 @@ int main(int argc, char *argv[])
        }
        if (mdi->array.level != UnSet) {
                fprintf(stderr, "mdmon: %s is not a container - cannot monitor\n",
-                       container_name);
+                       devname);
                exit(3);
        }
        if (mdi->array.major_version != -1 ||
            mdi->array.minor_version != -2) {
                fprintf(stderr, "mdmon: %s does not use external metadata - cannot monitor\n",
-                       container_name);
+                       devname);
                exit(3);
        }
 
        container->ss = find_metadata_methods(mdi->text_version);
        if (container->ss == NULL) {
                fprintf(stderr, "mdmon: %s uses unknown metadata: %s\n",
-                       container_name, mdi->text_version);
+                       devname, mdi->text_version);
                exit(3);
        }
 
@@ -481,9 +508,9 @@ int main(int argc, char *argv[])
        }
        container->sock = make_control_sock(container->devname);
 
-       if (container->ss->load_super(container, mdfd, container_name)) {
+       if (container->ss->load_super(container, mdfd, devname)) {
                fprintf(stderr, "mdmon: Cannot load metadata for %s\n",
-                       container_name);
+                       devname);
                exit(3);
        }
        close(mdfd);