imsm: FIX: Check maximum allowed degradation level in open_backup_targets()

Any degradation during opening any backup device can causes error
and array assembly failure.

Allow for degradation during opening backup devices.
This allows for degraded array assembly.

Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/super-intel.c b/super-intel.c
index 5f9842938e93f103ac079abe552c6cde574ff698..9f664c8253ec4155fb1ec60f683562d829c7b680 100644 (file)
--- a/super-intel.c
+++ b/super-intel.c
@@ -8018,6 +8018,75 @@ static void imsm_delete(struct intel_super *super, struct dl **dlp, unsigned ind
        }
 }
 #endif /* MDASSEMBLE */
+
+static void close_targets(int *targets, int new_disks)
+{
+       int i;
+
+       if (!targets)
+               return;
+
+       for (i = 0; i < new_disks; i++) {
+               if (targets[i] >= 0) {
+                       close(targets[i]);
+                       targets[i] = -1;
+               }
+       }
+}
+
+static int imsm_get_allowed_degradation(int level, int raid_disks,
+                                       struct intel_super *super,
+                                       struct imsm_dev *dev)
+{
+       switch (level) {
+       case 10:{
+               int ret_val = 0;
+               struct imsm_map *map;
+               int i;
+
+               ret_val = raid_disks/2;
+               /* check map if all disks pairs not failed
+                * in both maps
+                */
+               map = get_imsm_map(dev, 0);
+               for (i = 0; i < ret_val; i++) {
+                       int degradation = 0;
+                       if (get_imsm_disk(super, i) == NULL)
+                               degradation++;
+                       if (get_imsm_disk(super, i + 1) == NULL)
+                               degradation++;
+                       if (degradation == 2)
+                               return 0;
+               }
+               map = get_imsm_map(dev, 1);
+               /* if there is no second map
+                * result can be returned
+                */
+               if (map == NULL)
+                       return ret_val;
+               /* check degradation in second map
+                */
+               for (i = 0; i < ret_val; i++) {
+                       int degradation = 0;
+               if (get_imsm_disk(super, i) == NULL)
+                               degradation++;
+                       if (get_imsm_disk(super, i + 1) == NULL)
+                               degradation++;
+                       if (degradation == 2)
+                               return 0;
+               }
+               return ret_val;
+       }
+       case 5:
+               return 1;
+       case 6:
+               return 2;
+       default:
+               return 0;
+       }
+}
+
+
 /*******************************************************************************
  * Function:   open_backup_targets
  * Description:        Function opens file descriptors for all devices given in
@@ -8026,14 +8095,18 @@ static void imsm_delete(struct intel_super *super, struct dl **dlp, unsigned ind
  *     info            : general array info
  *     raid_disks      : number of disks
  *     raid_fds        : table of device's file descriptors
+ *     super           : intel super for raid10 degradation check
+ *     dev             : intel device for raid10 degradation check
  * Returns:
  *      0 : success
  *     -1 : fail
  ******************************************************************************/
-int open_backup_targets(struct mdinfo *info, int raid_disks, int *raid_fds)
+int open_backup_targets(struct mdinfo *info, int raid_disks, int *raid_fds,
+                       struct intel_super *super, struct imsm_dev *dev)
 {
        struct mdinfo *sd;
        int i;
+       int opened = 0;
 
        for (i = 0; i < raid_disks; i++)
                raid_fds[i] = -1;
@@ -8055,8 +8128,19 @@ int open_backup_targets(struct mdinfo *info, int raid_disks, int *raid_fds)
                raid_fds[sd->disk.raid_disk] = dev_open(dn, O_RDWR);
                if (raid_fds[sd->disk.raid_disk] < 0) {
                        fprintf(stderr, "cannot open component\n");
-                       return -1;
+                       continue;
                }
+               opened++;
+       }
+       /* check if maximum array degradation level is not exceeded
+       */
+       if ((raid_disks - opened) >
+                       imsm_get_allowed_degradation(info->new_level,
+                                                    raid_disks,
+                                                    super, dev)) {
+               fprintf(stderr, "Not enough disks can be opened.\n");
+               close_targets(raid_fds, raid_disks);
+               return -2;
        }
        return 0;
 }
@@ -8189,7 +8273,8 @@ int save_backup_imsm(struct supertype *st,
                target_offsets[i] -= start/data_disks;
        }
 
-       if (open_backup_targets(info, new_disks, targets))
+       if (open_backup_targets(info, new_disks, targets,
+                               super, dev))
                goto abort;
 
        dest_layout = imsm_level_to_layout(map_dest->raid_level);
@@ -8215,9 +8300,7 @@ int save_backup_imsm(struct supertype *st,
 
 abort:
        if (targets) {
-               for (i = 0; i < new_disks; i++)
-                       if (targets[i] >= 0)
-                               close(targets[i]);
+               close_targets(targets, new_disks);
                free(targets);
        }
        free(target_offsets);
@@ -8346,7 +8429,7 @@ int recover_backup_imsm(struct supertype *st, struct mdinfo *info)
        if (!targets)
                goto abort;
 
-       if (open_backup_targets(info, new_disks, targets)) {
+       if (open_backup_targets(info, new_disks, targets, super, id->dev)) {
                fprintf(stderr,
                        Name ": Cannot open some devices belonging to array.\n");
                goto abort;