Check write journal in incremental

If journal device is missing, do not start the array, and shows:

./mdadm -I /dev/sdf
mdadm: journal device is missing, not safe to start yet.

The array will be started when the journal device is attached with -I

./mdadm -I /dev/sdb1
mdadm: /dev/sdb1 attached to /dev/md/0_0, which has been started.

To force start without journal device:

./mdadm -I /dev/sdf --run
mdadm: Trying to run with missing journal device
mdadm: /dev/sdf attached to /dev/md/0_0, which has been started.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>

diff --git a/Incremental.c b/Incremental.c
index 43fddfdc87b1bdbb27fbd013f7afcf46a4f33e27..5b2974c384f66eaad17a18f8f34ce9e291a4c674 100644 (file)
--- a/Incremental.c
+++ b/Incremental.c
@@ -35,7 +35,7 @@
 
 static int count_active(struct supertype *st, struct mdinfo *sra,
                        int mdfd, char **availp,
-                       struct mdinfo *info);
+                       struct mdinfo *info, int *journal_device_missing);
 static void find_reject(int mdfd, struct supertype *st, struct mdinfo *sra,
                        int number, __u64 events, int verbose,
                        char *array_name);
@@ -104,6 +104,7 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
        struct map_ent target_array;
        int have_target;
        char *devname = devlist->devname;
+       int journal_device_missing = 0;
 
        struct createinfo *ci = conf_get_create_info();
 
@@ -519,7 +520,7 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
        sysfs_free(sra);
        sra = sysfs_read(mdfd, NULL, (GET_DEVS | GET_STATE |
                                    GET_OFFSET | GET_SIZE));
-       active_disks = count_active(st, sra, mdfd, &avail, &info);
+       active_disks = count_active(st, sra, mdfd, &avail, &info, &journal_device_missing);
        if (enough(info.array.level, info.array.raid_disks,
                   info.array.layout, info.array.state & 1,
                   avail) == 0) {
@@ -549,10 +550,12 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
        }
 
        map_unlock(&map);
-       if (c->runstop > 0 || active_disks >= info.array.working_disks) {
+       if (c->runstop > 0 || (!journal_device_missing && active_disks >= info.array.working_disks)) {
                struct mdinfo *dsk;
                /* Let's try to start it */
 
+               if (journal_device_missing)
+                       pr_err("Trying to run with missing journal device\n");
                if (info.reshape_active && !(info.reshape_active & RESHAPE_NO_BACKUP)) {
                        pr_err("%s: This array is being reshaped and cannot be started\n",
                               chosen_name);
@@ -619,6 +622,8 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
        } else {
                if (c->export) {
                        printf("MD_STARTED=unsafe\n");
+               } else if (journal_device_missing) {
+                       pr_err("Journal device is missing, not safe to start yet.\n");
                } else if (c->verbose >= 0)
                        pr_err("%s attached to %s, not enough to start safely.\n",
                               devname, chosen_name);
@@ -685,7 +690,8 @@ static void find_reject(int mdfd, struct supertype *st, struct mdinfo *sra,
 
 static int count_active(struct supertype *st, struct mdinfo *sra,
                        int mdfd, char **availp,
-                       struct mdinfo *bestinfo)
+                       struct mdinfo *bestinfo,
+                       int *journal_device_missing)
 {
        /* count how many devices in sra think they are active */
        struct mdinfo *d;
@@ -699,6 +705,8 @@ static int count_active(struct supertype *st, struct mdinfo *sra,
        int devnum;
        int b, i;
        int raid_disks = 0;
+       int require_journal_dev = 0;
+       int has_journal_dev = 0;
 
        if (!sra)
                return 0;
@@ -719,8 +727,19 @@ static int count_active(struct supertype *st, struct mdinfo *sra,
                close(dfd);
                if (ok != 0)
                        continue;
+
+               if (st->ss->require_journal) {
+                       require_journal_dev = st->ss->require_journal(st);
+                       if (require_journal_dev == 2) {
+                               pr_err("BUG: Superblock not loaded in Incremental.c:count_active\n");
+                               return 0;
+                       }
+               }
+
                info.array.raid_disks = raid_disks;
                st->ss->getinfo_super(st, &info, devmap + raid_disks * devnum);
+               if (info.disk.raid_disk == MD_DISK_ROLE_JOURNAL)
+                       has_journal_dev = 1;
                if (!avail) {
                        raid_disks = info.array.raid_disks;
                        avail = xcalloc(raid_disks, 1);
@@ -770,6 +789,10 @@ static int count_active(struct supertype *st, struct mdinfo *sra,
                        replcnt++;
                st->ss->free_super(st);
        }
+
+       if (require_journal_dev && !has_journal_dev)
+               *journal_device_missing = 1;
+
        if (!avail)
                return 0;
        /* We need to reject any device that thinks the best device is