Monitor: minor optimisation to spare migration.

Only try spare migration if we know that at least one array is
degraded.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/Monitor.c b/Monitor.c
index be8d5904d6addf7f51a3b554c640750ea7fdbb1a..5c86c194ff08c6c1669545bb4bbb5e5288f19acd 100644 (file)
--- a/Monitor.c
+++ b/Monitor.c
@@ -62,10 +62,10 @@ static int make_daemon(char *pidfile);
 static int check_one_sharer(int scan);
 static void alert(char *event, char *dev, char *disc, char *mailaddr, char *mailfrom,
                  char *cmd, int dosyslog);
-static void check_array(struct state *st, struct mdstat_ent *mdstat,
-                       int test, char *mailaddr,
-                       char *mailfrom, char *alert_cmd, int dosyslog,
-                       int increments);
+static int check_array(struct state *st, struct mdstat_ent *mdstat,
+                      int test, char *mailaddr,
+                      char *mailfrom, char *alert_cmd, int dosyslog,
+                      int increments);
 static int add_new_arrays(struct mdstat_ent *mdstat, struct state *statelist,
                          int test, char *mailaddr, char *mailfrom,
                          char *alert_cmd, int dosyslog);
@@ -212,14 +212,16 @@ int Monitor(struct mddev_dev *devlist,
        while (! finished) {
                int new_found = 0;
                struct state *st;
+               int anydegraded = 0;
 
                if (mdstat)
                        free_mdstat(mdstat);
                mdstat = mdstat_read(oneshot?0:1, 0);
 
                for (st=statelist; st; st=st->next)
-                       check_array(st, mdstat, test, mailaddr, mailfrom,
-                                   alert_cmd, dosyslog, increments);
+                       if (check_array(st, mdstat, test, mailaddr, mailfrom,
+                                       alert_cmd, dosyslog, increments))
+                               anydegraded = 1;
                
                /* now check if there are any new devices found in mdstat */
                if (scan)
@@ -231,7 +233,7 @@ int Monitor(struct mddev_dev *devlist,
                 * Look for another array with spare > 0 and active == raid and same spare_group
                 *  if found, choose a device and hotremove/hotadd
                 */
-               if (share)
+               if (share && anydegraded)
                        try_spare_migration(statelist, mailaddr, mailfrom,
                                            alert_cmd, dosyslog);
                if (!new_found) {
@@ -410,10 +412,10 @@ static void alert(char *event, char *dev, char *disc, char *mailaddr, char *mail
        }
 }
 
-static void check_array(struct state *st, struct mdstat_ent *mdstat,
-                       int test, char *mailaddr,
-                       char *mailfrom, char *alert_cmd, int dosyslog,
-                       int increments)
+static int check_array(struct state *st, struct mdstat_ent *mdstat,
+                      int test, char *mailaddr,
+                      char *mailfrom, char *alert_cmd, int dosyslog,
+                      int increments)
 {
        struct { int state, major, minor; } info[MaxDisks];
        mdu_array_info_t array;
@@ -432,7 +434,7 @@ static void check_array(struct state *st, struct mdstat_ent *mdstat,
 /*                                     fprintf(stderr, Name ": cannot open %s: %s\n",
                                        dev, strerror(errno));
 */                             st->err=1;
-               return;
+               return 0;
        }
        fcntl(fd, F_SETFD, FD_CLOEXEC);
        if (ioctl(fd, GET_ARRAY_INFO, &array)<0) {
@@ -443,7 +445,7 @@ static void check_array(struct state *st, struct mdstat_ent *mdstat,
                                        dev, strerror(errno));
 */                             st->err=1;
                close(fd);
-               return;
+               return 0;
        }
        /* It's much easier to list what array levels can't
         * have a device disappear than all of them that can
@@ -454,7 +456,7 @@ static void check_array(struct state *st, struct mdstat_ent *mdstat,
                              mailaddr, mailfrom, alert_cmd, dosyslog);
                st->err = 1;
                close(fd);
-               return;
+               return 0;
        }
        if (st->devnum == INT_MAX) {
                struct stat stb;
@@ -478,7 +480,7 @@ static void check_array(struct state *st, struct mdstat_ent *mdstat,
                 * or re-created after reading mdstat*/
                st->err = 1;
                close(fd);
-               return;
+               return 0;
        }
        /* this array is in /proc/mdstat */
        if (array.utime == 0)
@@ -495,7 +497,7 @@ static void check_array(struct state *st, struct mdstat_ent *mdstat,
                    ))) {
                close(fd);
                st->err = 0;
-               return;
+               return 0;
        }
        if (st->utime == 0 && /* new array */
            mse->pattern && strchr(mse->pattern, '_') /* degraded */
@@ -623,6 +625,9 @@ static void check_array(struct state *st, struct mdstat_ent *mdstat,
        st->utime = array.utime;
        st->raid = array.raid_disks;
        st->err = 0;
+       if ((st->active < st->raid) && st->spare == 0)
+               return 1;
+       return 0;
 }
 
 static int add_new_arrays(struct mdstat_ent *mdstat, struct state *statelist,