FIX: use md position to reshape restart

[thirdparty/mdadm.git] / Grow.c

diff --git a/Grow.c b/Grow.c
index 70bdee113f0b688c975003ad31aa0b720dd76e65..6b1380a2fbdc00381fe9590ebf48f21f80c5f01d 100644 (file)
--- a/Grow.c
+++ b/Grow.c
@@ -1862,6 +1862,55 @@ release:
        return rv;
 }
 
+/* verify_reshape_position()
+ *     Function checks if reshape position in metadata is not farther
+ *     than position in md.
+ * Return value:
+ *      0 : not valid sysfs entry
+ *             it can be caused by not started reshape, it should be started
+ *             by reshape array or raid0 array is before takeover
+ *     -1 :    error, reshape position is obviously wrong
+ *      1 :    success, reshape progress correct or updated
+*/
+static int verify_reshape_position(struct mdinfo *info, int level)
+{
+       int ret_val = 0;
+       char buf[40];
+
+       /* read sync_max, failure can mean raid0 array */
+       if (sysfs_get_str(info, NULL, "sync_max", buf, 40) > 0) {
+               char *ep;
+               unsigned long long position = strtoull(buf, &ep, 0);
+
+               dprintf(Name": Read sync_max sysfs entry is: %s\n", buf);
+               if (!(ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))) {
+                       position *= get_data_disks(level,
+                                                  info->new_layout,
+                                                  info->array.raid_disks);
+                       if (info->reshape_progress < position) {
+                               dprintf("Corrected reshape progress (%llu) to "
+                                       "md position (%llu)\n",
+                                       info->reshape_progress, position);
+                               info->reshape_progress = position;
+                               ret_val = 1;
+                       } else if (info->reshape_progress > position) {
+                               fprintf(stderr, Name ": Fatal error: array "
+                                       "reshape was not properly frozen "
+                                       "(expected reshape position is %llu, "
+                                       "but reshape progress is %llu.\n",
+                                       position, info->reshape_progress);
+                               ret_val = -1;
+                       } else {
+                               dprintf("Reshape position in md and metadata "
+                                       "are the same;");
+                               ret_val = 1;
+                       }
+               }
+       }
+
+       return ret_val;
+}
+
 static int reshape_array(char *container, int fd, char *devname,
                         struct supertype *st, struct mdinfo *info,
                         int force, struct mddev_dev *devlist,
@@ -2251,9 +2300,16 @@ started:
 
        sra->new_chunk = info->new_chunk;
 
-       if (restart)
+       if (restart) {
+               /* for external metadata checkpoint saved by mdmon can be lost
+                * or missed /due to e.g. crash/. Check if md is not during
+                * restart farther than metadata points to.
+                * If so, this means metadata information is obsolete.
+                */
+               if (st->ss->external)
+                       verify_reshape_position(info, reshape.level);
                sra->reshape_progress = info->reshape_progress;
-       else {
+       } else {
                sra->reshape_progress = 0;
                if (reshape.after.data_disks < reshape.before.data_disks)
                        /* start from the end of the new array */
@@ -3765,8 +3821,6 @@ int Grow_continue_command(char *devname, int fd,
        char buf[40];
        int cfd = -1;
        int fd2 = -1;
-       char *ep;
-       unsigned long long position;
 
        dprintf("Grow continue from command line called for %s\n",
                devname);
@@ -3894,28 +3948,8 @@ int Grow_continue_command(char *devname, int fd,
        /* verify that array under reshape is started from
         * correct position
         */
-       ret_val = sysfs_get_str(content, NULL, "sync_max", buf, 40);
-       if (ret_val <= 0) {
-               fprintf(stderr, Name
-                       ": cannot open verify reshape progress for %s (%i)\n",
-                       content->sys_name, ret_val);
-               ret_val = 1;
-               goto Grow_continue_command_exit;
-       }
-       dprintf(Name ": Read sync_max sysfs entry is: %s\n", buf);
-       position = strtoull(buf, &ep, 0);
-       if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' ')) {
-               fprintf(stderr, Name ": Fatal error: array reshape was"
-                       " not properly frozen\n");
-               ret_val = 1;
-               goto Grow_continue_command_exit;
-       }
-       position *= get_data_disks(map_name(pers, mdstat->level),
-                                  content->new_layout,
-                                  content->array.raid_disks);
-       if (position != content->reshape_progress) {
-               fprintf(stderr, Name ": Fatal error: array reshape was"
-                       " not properly frozen.\n");
+       if (verify_reshape_position(content,
+                                   map_name(pers, mdstat->level)) <= 0) {
                ret_val = 1;
                goto Grow_continue_command_exit;
        }