imsm: manage a list of missing disks

If a drive is removed while mdmon is not running we need a way to
identify what is missing and mark that disk as failed in the metadata.
At ->load_super() time create a list of missing disks defined as a disk
that is marked in-sync yet does not appear in super->disks.

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

diff --git a/super-intel.c b/super-intel.c
index 19c964f8843c5257e51e1ac2a701c57326c6a9d0..7f8dd3483271796a3dd5a53381f33a6c7fbf870e 100644 (file)
--- a/super-intel.c
+++ b/super-intel.c
@@ -180,6 +180,7 @@ struct intel_super {
                int fd;
        } *disks;
        struct dl *add; /* list of disks to add while mdmon active */
+       struct dl *missing; /* disks removed while we weren't looking */
        struct bbm_log *bbm_log;
 };
 
@@ -1321,12 +1322,19 @@ static void __free_imsm_disk(struct dl *d)
 }
 static void free_imsm_disks(struct intel_super *super)
 {
-       while (super->disks) {
-               struct dl *d = super->disks;
+       struct dl *d;
 
+       while (super->disks) {
+               d = super->disks;
                super->disks = d->next;
                __free_imsm_disk(d);
        }
+       while (super->missing) {
+               d = super->missing;
+               super->missing = d->next;
+               __free_imsm_disk(d);
+       }
+
 }
 
 /* free all the pieces hanging off of a super pointer */
@@ -1378,6 +1386,49 @@ static struct intel_super *alloc_super(int creating_imsm)
 }
 
 #ifndef MDASSEMBLE
+/* find_missing - helper routine for load_super_imsm_all that identifies
+ * disks that have disappeared from the system.  This routine relies on
+ * the mpb being uptodate, which it is at load time.
+ */
+static int find_missing(struct intel_super *super)
+{
+       int i;
+       struct imsm_super *mpb = super->anchor;
+       struct dl *dl;
+       struct imsm_disk *disk;
+       __u32 status;
+
+       for (i = 0; i < mpb->num_disks; i++) {
+               disk = __get_imsm_disk(mpb, i);
+               for (dl = super->disks; dl; dl = dl->next)
+                       if (serialcmp(dl->disk.serial, disk->serial) == 0)
+                               break;
+               if (dl)
+                       continue;
+               /* ok we have a 'disk' without a live entry in
+                * super->disks
+                */
+               status = __le32_to_cpu(disk->status);
+               if (status & FAILED_DISK || !(status & USABLE_DISK))
+                       continue; /* never mind, already marked */
+
+               dl = malloc(sizeof(*dl));
+               if (!dl)
+                       return 1;
+               dl->major = 0;
+               dl->minor = 0;
+               dl->fd = -1;
+               dl->devname = strdup("missing");
+               dl->index = i;
+               serialcpy(dl->serial, disk->serial);
+               dl->disk = *disk;
+               dl->next = super->missing;
+               super->missing = dl;
+       }
+
+       return 0;
+}
+
 static int load_super_imsm_all(struct supertype *st, int fd, void **sbp,
                               char *devname, int keep_fd)
 {
@@ -1462,6 +1513,12 @@ static int load_super_imsm_all(struct supertype *st, int fd, void **sbp,
                        close(dfd);
        }
 
+
+       if (find_missing(super) != 0) {
+               free_imsm(super);
+               return 2;
+       }
+
        if (st->subarray[0]) {
                if (atoi(st->subarray) <= super->anchor->num_raid_devs)
                        super->current_vol = atoi(st->subarray);
@@ -1861,6 +1918,8 @@ static int write_super_imsm(struct intel_super *super, int doclose)
                else
                        mpb->disk[d->index] = d->disk;
        }
+       for (d = super->missing; d; d = d->next)
+               mpb->disk[d->index] = d->disk;
 
        for (i = 0; i < mpb->num_raid_devs; i++) {
                struct imsm_dev *dev = __get_imsm_dev(mpb, i);
@@ -2471,6 +2530,18 @@ static int is_rebuilding(struct imsm_dev *dev)
                return 0;
 }
 
+static void mark_failure(struct imsm_disk *disk)
+{
+       __u32 status = __le32_to_cpu(disk->status);
+
+       if (status & FAILED_DISK)
+               return;
+       status |= FAILED_DISK;
+       disk->status = __cpu_to_le32(status);
+       disk->scsi_id = __cpu_to_le32(~(__u32)0);
+       memmove(&disk->serial[0], &disk->serial[1], MAX_RAID_SERIAL_LEN - 1);
+}
+
 /* Handle dirty -> clean transititions and resync.  Degraded and rebuild
  * states are handled in imsm_set_disk() with one exception, when a
  * resync is stopped due to a new failure this routine will set the
@@ -2485,6 +2556,17 @@ static int imsm_set_array_state(struct active_array *a, int consistent)
        int failed = imsm_count_failed(super, dev);
        __u8 map_state = imsm_check_degraded(super, dev, failed);
 
+       /* before we activate this array handle any missing disks */
+       if (consistent == 2 && super->missing) {
+               struct dl *dl;
+
+               dprintf("imsm: mark missing\n");
+               end_migration(dev, map_state);
+               for (dl = super->missing; dl; dl = dl->next)
+                       mark_failure(&dl->disk);
+               super->updates_pending++;
+       }
+               
        if (consistent == 2 &&
            (!is_resync_complete(a) ||
             map_state != IMSM_T_STATE_NORMAL ||
@@ -2557,12 +2639,10 @@ static void imsm_set_disk(struct active_array *a, int n, int state)
        /* check for new failures */
        status = __le32_to_cpu(disk->status);
        if ((state & DS_FAULTY) && !(status & FAILED_DISK)) {
-               status |= FAILED_DISK;
-               disk->status = __cpu_to_le32(status);
-               disk->scsi_id = __cpu_to_le32(~(__u32)0);
-               memmove(&disk->serial[0], &disk->serial[1], MAX_RAID_SERIAL_LEN - 1);
+               mark_failure(disk);
                super->updates_pending++;
        }
+
        /* check if in_sync */
        if (state & DS_INSYNC && ord & IMSM_ORD_REBUILD) {
                struct imsm_map *migr_map = get_imsm_map(dev, 1);
@@ -2986,12 +3066,18 @@ static void imsm_process_update(struct supertype *st,
                if (!found) {
                        struct dl **dlp;
 
+                       /* We know that 'manager' isn't touching anything,
+                        * so it is safe to delete
+                        */
                        for (dlp = &super->disks; *dlp; dlp = &(*dlp)->next)
                                if ((*dlp)->index == victim)
                                        break;
-                       /* We know that 'manager' isn't touching anything,
-                        * so it is safe to:
-                        */
+
+                       /* victim may be on the missing list */
+                       if (!*dlp)
+                               for (dlp = &super->missing; *dlp; dlp = &(*dlp)->next)
+                                       if ((*dlp)->index == victim)
+                                               break;
                        imsm_delete(super, dlp, victim);
                }
                break;
@@ -3174,6 +3260,9 @@ static void imsm_delete(struct intel_super *super, struct dl **dlp, int index)
        for (iter = super->disks; iter; iter = iter->next)
                if (iter->index > index)
                        iter->index--;
+       for (iter = super->missing; iter; iter = iter->next)
+               if (iter->index > index)
+                       iter->index--;
 
        for (i = 0; i < mpb->num_raid_devs; i++) {
                dev = get_imsm_dev(super, i);