[PATCH] yet more extras/multipath

* implement a reschedule flag in /var/run. Last thing the prog do before
exit is check if a call to multipath was done (but canceled by
/var/run/multipath.run check) during its execution. If so restart the
main loop.
* implement a blacklist of sysfs bdev to not bother with for now (hd,
md, dm, sr, scd, ram, raw). This avoid sending SG_IO to unappropiate
devices.

Compiles & survive "while true;do (./multipath -v &);done"

diff --git a/extras/multipath/main.c b/extras/multipath/main.c
index 9bceb265ba1fe4a2e1cf48b1f67868fde79e0d96..bc65899ce14376706cf3d8b86b5d15a8e9563024 100644 (file)
--- a/extras/multipath/main.c
+++ b/extras/multipath/main.c
@@ -195,6 +195,31 @@ basename(char * str1, char * str2)
        strcpy(str2, ++p);
 }
 
+static int
+blacklist (char * dev) {
+       int i;
+       static struct {
+               char * headstr;
+               int lengh;
+       } blist[] = {
+               {"cciss", 5},
+               {"hd", 2},
+               {"md", 2},
+               {"dm", 2},
+               {"sr", 2},
+               {"scd", 3},
+               {"ram", 3},
+               {"raw", 3},
+               {NULL, 0},
+       };
+
+       for (i = 0; blist[i].lengh; i++) {
+               if (strncmp(dev, blist[i].headstr, blist[i].lengh))
+                       return 1;
+       }
+       return 0;
+}
+
 static int
 get_all_paths_sysfs(struct env * conf, struct path * all_paths)
 {
@@ -211,6 +236,8 @@ get_all_paths_sysfs(struct env * conf, struct path * all_paths)
        sdir = sysfs_open_directory(block_path);
        sysfs_read_directory(sdir);
        dlist_for_each_data(sdir->subdirs, devp, struct sysfs_directory) {
+               if (blacklist(devp->name))
+                       continue;
                sysfs_read_directory(devp);
                if(devp->links == NULL)
                        continue;
@@ -661,7 +688,7 @@ usage(char * progname)
 }
 
 static int
-running(char * run) {
+filepresent(char * run) {
        struct stat buf;
 
        if(!stat(run, &buf))
@@ -673,6 +700,7 @@ int
 main(int argc, char *argv[])
 {
        char * run = "/var/run/multipath.run";
+       char * resched = "/var/run/multipath.reschedule";
        struct multipath * mp;
        struct path * all_paths;
        struct scsi_dev * all_scsi_ids;
@@ -715,18 +743,17 @@ main(int argc, char *argv[])
 
        }
 
-       if (running(run)) {
+       if (filepresent(run)) {
                if (conf.verbose) {
                        fprintf(stderr, "Already running.\n");
                        fprintf(stderr, "If you know what you do, please ");
                        fprintf(stderr, "remove %s\n", run);
                }
+               /* leave a trace that we were called while already running */
+               open(resched, O_CREAT);
                return 1;
        }
 
-       if(!open(run, O_CREAT))
-               exit(1);
-
        /* dynamic allocations */
        mp = malloc(conf.max_devs * sizeof(struct multipath));
        all_paths = malloc(conf.max_devs * sizeof(struct path));
@@ -735,6 +762,9 @@ main(int argc, char *argv[])
                unlink(run);
                exit(1);
        }
+start:
+       if(!open(run, O_CREAT))
+               exit(1);
 
        if (!conf.with_sysfs) {
                get_all_scsi_ids(&conf, all_scsi_ids);
@@ -764,5 +794,12 @@ main(int argc, char *argv[])
                }
        }
        unlink(run);
+
+       /* start again if we were ask to during this process run */
+       /* ie. do not loose an event-asked run */
+       if (filepresent(resched)) {
+               unlink(resched);
+               goto start;
+       }
        exit(0);
 }