UBI: fix error handling in erase worker

Do not switch to read-only mode in case of -EINTR and some
other obvious cases. Switch to RO mode only when we do not
know what is the error.

Reported-by: Vinit Agnihotri <vinit.agnihotri@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 48 insertions, 41 deletions

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index d512cf16350d..9de953762097 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -1060,9 +1060,8 @@ out_unlock:
 static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
                         int cancel)
 {
-        int err;
         struct ubi_wl_entry *e = wl_wrk->e;
-        int pnum = e->pnum;
+        int pnum = e->pnum, err, need;
 
         if (cancel) {
                 dbg_wl("cancel erasure of PEB %d EC %d", pnum, e->ec);
@@ -1097,62 +1096,70 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
         kfree(wl_wrk);
         kmem_cache_free(wl_entries_slab, e);
 
-        if (err != -EIO) {
+        if (err == -EINTR || err == -ENOMEM || err == -EAGAIN ||
+            err == -EBUSY) {
+                int err1;
+
+                /* Re-schedule the LEB for erasure */
+                err1 = schedule_erase(ubi, e, 0);
+                if (err1) {
+                        err = err1;
+                        goto out_ro;
+                }
+                return err;
+        } else if (err != -EIO) {
                 /*
                  * If this is not %-EIO, we have no idea what to do. Scheduling
                  * this physical eraseblock for erasure again would cause
                  * errors again and again. Well, lets switch to RO mode.
                  */
-                ubi_ro_mode(ubi);
-                return err;
+                goto out_ro;
         }
 
         /* It is %-EIO, the PEB went bad */
 
         if (!ubi->bad_allowed) {
                 ubi_err("bad physical eraseblock %d detected", pnum);
-                ubi_ro_mode(ubi);
-                err = -EIO;
-        } else {
-                int need;
-
-                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);
-                }
+                goto out_ro;
+        }
 
-                if (ubi->beb_rsvd_pebs == 0) {
-                        spin_unlock(&ubi->volumes_lock);
-                        ubi_err("no reserved physical eraseblocks");
-                        ubi_ro_mode(ubi);
-                        return -EIO;
-                }
+        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_msg("mark PEB %d as bad", pnum);
+                ubi_err("no reserved physical eraseblocks");
+                goto out_ro;
+        }
 
-                err = ubi_io_mark_bad(ubi, pnum);
-                if (err) {
-                        ubi_ro_mode(ubi);
-                        return err;
-                }
+        spin_unlock(&ubi->volumes_lock);
+        ubi_msg("mark PEB %d as bad", pnum);
 
-                spin_lock(&ubi->volumes_lock);
-                ubi->beb_rsvd_pebs -= 1;
-                ubi->bad_peb_count += 1;
-                ubi->good_peb_count -= 1;
-                ubi_calculate_reserved(ubi);
-                if (ubi->beb_rsvd_pebs == 0)
-                        ubi_warn("last PEB from the reserved pool was used");
-                spin_unlock(&ubi->volumes_lock);
-        }
+        err = ubi_io_mark_bad(ubi, pnum);
+        if (err)
+                goto out_ro;
+
+        spin_lock(&ubi->volumes_lock);
+        ubi->beb_rsvd_pebs -= 1;
+        ubi->bad_peb_count += 1;
+        ubi->good_peb_count -= 1;
+        ubi_calculate_reserved(ubi);
+        if (ubi->beb_rsvd_pebs == 0)
+                ubi_warn("last PEB from the reserved pool was used");
+        spin_unlock(&ubi->volumes_lock);
+
+        return err;
 
+out_ro:
+        ubi_ro_mode(ubi);
         return err;
 }