mdmon: add debug print statements for profiling mdmon

for development only as console output can block leading to monitor deadlocks
in low mem situations

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

diff --git a/managemon.c b/managemon.c
index 43db56692a4f61ad006767f542f280dee9752077..9f3520e8ea8e475e7a535071550fd01943a69aca 100644 (file)
--- a/managemon.c
+++ b/managemon.c
@@ -105,6 +105,7 @@ static void free_aa(struct active_array *aa)
        /* Note that this doesn't close fds if they are being used
         * by a clone.  ->container will be set for a clone
         */
+       dprintf("%s: devnum: %d\n", __func__, aa->devnum);
        if (!aa->container)
                close_aa(aa);
        while (aa->info.devs) {
@@ -380,6 +381,8 @@ static void manage_new(struct mdstat_ent *mdstat,
        new->info.state_fd = sysfs_open(new->devnum, NULL, "array_state");
        new->resync_start_fd = sysfs_open(new->devnum, NULL, "resync_start");
        new->resync_start = 0;
+       dprintf("%s: inst: %d action: %d state: %d\n", __func__, atoi(inst),
+               new->action_fd, new->info.state_fd);
 
        sysfs_free(mdi);
        // finds and compares.

diff --git a/mdmon.h b/mdmon.h
index 11320ef6994dc65bcd7cb701a77b939d719f23b4..f1b6d76ea367a2ec55cb06df41bb173e4f0c0930 100644 (file)
--- a/mdmon.h
+++ b/mdmon.h
@@ -1,3 +1,10 @@
+#ifdef DEBUG
+#define dprintf(fmt, arg...) \
+       fprintf(stderr, fmt, ##arg)
+#else
+#define dprintf(fmt, arg...) \
+        ({ if (0) fprintf(stderr, fmt, ##arg); 0; })
+#endif
 
 enum array_state { clear, inactive, suspended, readonly, read_auto,
                   clean, active, write_pending, active_idle, bad_word};

diff --git a/monitor.c b/monitor.c
index 5a95149027da2f28244a5d8ff5b8728f7e39f7ef..6377cc4a01551018bf77b76e7eabd6497ecfea40 100644 (file)
--- a/monitor.c
+++ b/monitor.c
@@ -281,12 +281,17 @@ static int read_and_act(struct active_array *a)
        }
 
        a->container->ss->sync_metadata(a->container);
+       dprintf("%s: update[%d]: (", __func__, a->info.container_member);
 
        /* Effect state changes in the array */
-       if (a->next_state != bad_word)
+       if (a->next_state != bad_word) {
+               dprintf(" state:%s", array_states[a->next_state]);
                write_attr(array_states[a->next_state], a->info.state_fd);
-       if (a->next_action != bad_action)
+       }
+       if (a->next_action != bad_action) {
                write_attr(sync_actions[a->next_action], a->action_fd);
+               dprintf(" action:%s", array_states[a->next_state]);
+       }
        for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
                if (mdi->next_state == DS_REMOVE && mdi->state_fd >= 0) {
                        int remove_result;
@@ -296,15 +301,20 @@ static int read_and_act(struct active_array *a)
                         * disk, we can simply wait until the next event to try
                         * again.
                         */
+                       dprintf(" %d:-blocked", mdi->disk.raid_disk);
                        remove_result = write_attr("remove", mdi->state_fd);
                        if (remove_result > 0) {
+                               dprintf(" %d:removed", mdi->disk.raid_disk);
                                close(mdi->state_fd);
                                mdi->state_fd = -1;
                        }
                }
-               if (mdi->next_state & DS_INSYNC)
+               if (mdi->next_state & DS_INSYNC) {
                        write_attr("+in_sync", mdi->state_fd);
+                       dprintf(" %d:+in_sync", mdi->disk.raid_disk);
+               }
        }
+       dprintf(" )\n");
 
        /* move curr_ to prev_ */
        a->prev_state = a->curr_state;
@@ -410,6 +420,36 @@ static int handle_pipe(struct md_generic_cmd *cmd, struct active_array *aa)
        return -1;
 }
 
+#ifdef DEBUG
+static void dprint_wake_reasons(fd_set *fds)
+{
+       int i;
+       char proc_path[256];
+       char link[256];
+       char *basename;
+       int rv;
+
+       fprintf(stderr, "monitor: wake ( ");
+       for (i = 0; i < FD_SETSIZE; i++) {
+               if (FD_ISSET(i, fds)) {
+                       sprintf(proc_path, "/proc/%d/fd/%d",
+                               (int) getpid(), i);
+
+                       rv = readlink(proc_path, link, sizeof(link) - 1);
+                       if (rv < 0) {
+                               fprintf(stderr, "%d:unknown ", i);
+                               continue;
+                       }
+                       link[rv] = '\0';
+                       basename = strrchr(link, '/');
+                       fprintf(stderr, "%d:%s ",
+                               i, basename ? ++basename : link);
+               }
+       }
+       fprintf(stderr, ")\n");
+}
+#endif
+
 static int wait_and_act(struct supertype *container, int pfd,
                        int monfd, int nowait)
 {
@@ -457,6 +497,7 @@ static int wait_and_act(struct supertype *container, int pfd,
                int fd = open(container->device_name, O_RDONLY|O_EXCL);
                if (fd >= 0 || errno != EBUSY) {
                        /* OK, we are safe to leave */
+                       dprintf("no arrays to monitor... exiting\n");
                        exit_now = 1;
                        signal_manager();
                        remove_pidfile(container->devname);
@@ -467,6 +508,10 @@ static int wait_and_act(struct supertype *container, int pfd,
        if (!nowait) {
                rv = select(maxfd+1, &rfds, NULL, NULL, NULL);
 
+               #ifdef DEBUG
+               dprint_wake_reasons(&rfds);
+               #endif
+
                if (rv <= 0)
                        return rv;
 

diff --git a/super-intel.c b/super-intel.c
index 0efc49c238c7c64e3d4e54b575e53d224fc4de4a..8ca491bd035e104ef52321745bc97fd5f345dca7 100644 (file)
--- a/super-intel.c
+++ b/super-intel.c
@@ -1644,7 +1644,7 @@ static struct mdinfo *container_content_imsm(struct supertype *st)
 static int imsm_open_new(struct supertype *c, struct active_array *a,
                         char *inst)
 {
-       fprintf(stderr, "imsm: open_new %s\n", inst);
+       dprintf("imsm: open_new %s\n", inst);
        a->info.container_member = atoi(inst);
        return 0;
 }
@@ -1742,7 +1742,7 @@ static void imsm_set_array_state(struct active_array *a, int consistent)
                if (!failed)
                        map_state = IMSM_T_STATE_NORMAL;
                if (map->map_state != map_state) {
-                       fprintf(stderr, "imsm: map_state %d: %d\n",
+                       dprintf("imsm: map_state %d: %d\n",
                                inst, map_state);
                        map->map_state = map_state;
                        super->updates_pending++;
@@ -1750,7 +1750,7 @@ static void imsm_set_array_state(struct active_array *a, int consistent)
        }
 
        if (dev->vol.dirty != dirty) {
-               fprintf(stderr, "imsm: mark '%s' (%llu)\n",
+               dprintf("imsm: mark '%s' (%llu)\n",
                        dirty?"dirty":"clean", a->resync_start);
 
                dev->vol.dirty = dirty;
@@ -1776,7 +1776,7 @@ static void imsm_set_disk(struct active_array *a, int n, int state)
        if (n < 0)
                return;
 
-       fprintf(stderr, "imsm: set_disk %d:%x\n", n, state);
+       dprintf("imsm: set_disk %d:%x\n", n, state);
 
        disk = get_imsm_disk(super->mpb, get_imsm_disk_idx(map, n));