2 files changed, 41 insertions, 21 deletions

diff --git a/drivers/mtd/ubi/misc.c b/drivers/mtd/ubi/misc.c
index 8bbfb444b895..d089df055484 100644
--- a/drivers/mtd/ubi/misc.c
+++ b/drivers/mtd/ubi/misc.c
@@ -121,10 +121,18 @@ void ubi_update_reserved(struct ubi_device *ubi)
  */
 void ubi_calculate_reserved(struct ubi_device *ubi)
 {
-        ubi->beb_rsvd_level = ubi->good_peb_count/100;
-        ubi->beb_rsvd_level *= CONFIG_MTD_UBI_BEB_RESERVE;
-        if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS)
-                ubi->beb_rsvd_level = MIN_RESEVED_PEBS;
+        /*
+         * Calculate the actual number of PEBs currently needed to be reserved
+         * for future bad eraseblock handling.
+         */
+        ubi->beb_rsvd_level = ubi->bad_peb_limit - ubi->bad_peb_count;
+        if (ubi->beb_rsvd_level < 0) {
+                ubi->beb_rsvd_level = 0;
+                ubi_warn("number of bad PEBs (%d) is above the expected limit "
+                         "(%d), not reserving any PEBs for bad PEB handling, "
+                         "will use available PEBs (if any)",
+                         ubi->bad_peb_count, ubi->bad_peb_limit);
+        }
 }
 
 /**
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index b6be644e7b85..bd05276252fb 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -978,9 +978,10 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
                         int cancel)
 {
         struct ubi_wl_entry *e = wl_wrk->e;
-        int pnum = e->pnum, err, need;
+        int pnum = e->pnum;
         int vol_id = wl_wrk->vol_id;
         int lnum = wl_wrk->lnum;
+        int err, available_consumed = 0;
 
         if (cancel) {
                 dbg_wl("cancel erasure of PEB %d EC %d", pnum, e->ec);
@@ -1045,20 +1046,14 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
         }
 
         spin_lock(&ubi->volumes_lock);
-        need = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs + 1;
-        if (need > 0) {
-                need = ubi->avail_pebs >= need ? need : ubi->avail_pebs;
-                ubi->avail_pebs -= need;
-                ubi->rsvd_pebs += need;
-                ubi->beb_rsvd_pebs += need;
-                if (need > 0)
-                        ubi_msg("reserve more %d PEBs", need);
-        }
-
         if (ubi->beb_rsvd_pebs == 0) {
-                spin_unlock(&ubi->volumes_lock);
-                ubi_err("no reserved physical eraseblocks");
-                goto out_ro;
+                if (ubi->avail_pebs == 0) {
+                        spin_unlock(&ubi->volumes_lock);
+                        ubi_err("no reserved/available physical eraseblocks");
+                        goto out_ro;
+                }
+                ubi->avail_pebs -= 1;
+                available_consumed = 1;
         }
         spin_unlock(&ubi->volumes_lock);
 
@@ -1068,19 +1063,36 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
                 goto out_ro;
 
         spin_lock(&ubi->volumes_lock);
-        ubi->beb_rsvd_pebs -= 1;
+        if (ubi->beb_rsvd_pebs > 0) {
+                if (available_consumed) {
+                        /*
+                         * The amount of reserved PEBs increased since we last
+                         * checked.
+                         */
+                        ubi->avail_pebs += 1;
+                        available_consumed = 0;
+                }
+                ubi->beb_rsvd_pebs -= 1;
+        }
         ubi->bad_peb_count += 1;
         ubi->good_peb_count -= 1;
         ubi_calculate_reserved(ubi);
-        if (ubi->beb_rsvd_pebs)
+        if (available_consumed)
+                ubi_warn("no PEBs in the reserved pool, used an available PEB");
+        else if (ubi->beb_rsvd_pebs)
                 ubi_msg("%d PEBs left in the reserve", ubi->beb_rsvd_pebs);
         else
-                ubi_warn("last PEB from the reserved pool was used");
+                ubi_warn("last PEB from the reserve was used");
         spin_unlock(&ubi->volumes_lock);
 
         return err;
 
 out_ro:
+        if (available_consumed) {
+                spin_lock(&ubi->volumes_lock);
+                ubi->avail_pebs += 1;
+                spin_unlock(&ubi->volumes_lock);
+        }
         ubi_ro_mode(ubi);
         return err;
 }