return 0;
}
+/**
+ * in_pq - check if a wear-leveling entry is present in the protection queue.
+ * @ubi: UBI device description object
+ * @e: the wear-leveling entry to check
+ *
+ * This function returns non-zero if @e is in the protection queue and zero
+ * if it is not.
+ */
+static inline int in_pq(const struct ubi_device *ubi, struct ubi_wl_entry *e)
+{
+ struct ubi_wl_entry *p;
+ int i;
+
+ for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i)
+ list_for_each_entry(p, &ubi->pq[i], u.list)
+ if (p == e)
+ return 1;
+
+ return 0;
+}
+
/**
* prot_queue_add - add physical eraseblock to the protection queue.
* @ubi: UBI device description object
return err;
}
+static bool scrub_possible(struct ubi_device *ubi, struct ubi_wl_entry *e)
+{
+ if (in_wl_tree(e, &ubi->scrub))
+ return false;
+ else if (in_wl_tree(e, &ubi->erroneous))
+ return false;
+ else if (ubi->move_from == e)
+ return false;
+ else if (ubi->move_to == e)
+ return false;
+
+ return true;
+}
+
+/**
+ * ubi_bitflip_check - Check an eraseblock for bitflips and scrub it if needed.
+ * @ubi: UBI device description object
+ * @pnum: the physical eraseblock to schedule
+ * @force: dont't read the block, assume bitflips happened and take action.
+ *
+ * This function reads the given eraseblock and checks if bitflips occured.
+ * In case of bitflips, the eraseblock is scheduled for scrubbing.
+ * If scrubbing is forced with @force, the eraseblock is not read,
+ * but scheduled for scrubbing right away.
+ *
+ * Returns:
+ * %EINVAL, PEB is out of range
+ * %ENOENT, PEB is no longer used by UBI
+ * %EBUSY, PEB cannot be checked now or a check is currently running on it
+ * %EAGAIN, bit flips happened but scrubbing is currently not possible
+ * %EUCLEAN, bit flips happened and PEB is scheduled for scrubbing
+ * %0, no bit flips detected
+ */
+int ubi_bitflip_check(struct ubi_device *ubi, int pnum, int force)
+{
+ int err;
+ struct ubi_wl_entry *e;
+
+ if (pnum < 0 || pnum >= ubi->peb_count) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ /*
+ * Pause all parallel work, otherwise it can happen that the
+ * erase worker frees a wl entry under us.
+ */
+ down_write(&ubi->work_sem);
+
+ /*
+ * Make sure that the wl entry does not change state while
+ * inspecting it.
+ */
+ spin_lock(&ubi->wl_lock);
+ e = ubi->lookuptbl[pnum];
+ if (!e) {
+ spin_unlock(&ubi->wl_lock);
+ err = -ENOENT;
+ goto out_resume;
+ }
+
+ /*
+ * Does it make sense to check this PEB?
+ */
+ if (!scrub_possible(ubi, e)) {
+ spin_unlock(&ubi->wl_lock);
+ err = -EBUSY;
+ goto out_resume;
+ }
+ spin_unlock(&ubi->wl_lock);
+
+ if (!force) {
+ mutex_lock(&ubi->buf_mutex);
+ err = ubi_io_read(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size);
+ mutex_unlock(&ubi->buf_mutex);
+ }
+
+ if (force || err == UBI_IO_BITFLIPS) {
+ /*
+ * Okay, bit flip happened, let's figure out what we can do.
+ */
+ spin_lock(&ubi->wl_lock);
+
+ /*
+ * Recheck. We released wl_lock, UBI might have killed the
+ * wl entry under us.
+ */
+ e = ubi->lookuptbl[pnum];
+ if (!e) {
+ spin_unlock(&ubi->wl_lock);
+ err = -ENOENT;
+ goto out_resume;
+ }
+
+ /*
+ * Need to re-check state
+ */
+ if (!scrub_possible(ubi, e)) {
+ spin_unlock(&ubi->wl_lock);
+ err = -EBUSY;
+ goto out_resume;
+ }
+
+ if (in_pq(ubi, e)) {
+ prot_queue_del(ubi, e->pnum);
+ wl_tree_add(e, &ubi->scrub);
+ spin_unlock(&ubi->wl_lock);
+
+ err = ensure_wear_leveling(ubi, 1);
+ } else if (in_wl_tree(e, &ubi->used)) {
+ rb_erase(&e->u.rb, &ubi->used);
+ wl_tree_add(e, &ubi->scrub);
+ spin_unlock(&ubi->wl_lock);
+
+ err = ensure_wear_leveling(ubi, 1);
+ } else if (in_wl_tree(e, &ubi->free)) {
+ rb_erase(&e->u.rb, &ubi->free);
+ ubi->free_count--;
+ spin_unlock(&ubi->wl_lock);
+
+ /*
+ * This PEB is empty we can schedule it for
+ * erasure right away. No wear leveling needed.
+ */
+ err = schedule_erase(ubi, e, UBI_UNKNOWN, UBI_UNKNOWN,
+ force ? 0 : 1, true);
+ } else {
+ spin_unlock(&ubi->wl_lock);
+ err = -EAGAIN;
+ }
+
+ if (!err && !force)
+ err = -EUCLEAN;
+ } else {
+ err = 0;
+ }
+
+out_resume:
+ up_write(&ubi->work_sem);
+out:
+
+ return err;
+}
+
/**
* tree_destroy - destroy an RB-tree.
* @ubi: UBI device description object
static int self_check_in_pq(const struct ubi_device *ubi,
struct ubi_wl_entry *e)
{
- struct ubi_wl_entry *p;
- int i;
-
if (!ubi_dbg_chk_gen(ubi))
return 0;
- for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i)
- list_for_each_entry(p, &ubi->pq[i], u.list)
- if (p == e)
- return 0;
+ if (in_pq(ubi, e))
+ return 0;
ubi_err(ubi, "self-check failed for PEB %d, EC %d, Protect queue",
e->pnum, e->ec);
projects / linux-2.6-block.git / commitdiff