UBI: handle write errors in WL worker
When a PEB is moved and a write error happens, UBI switches
to R/O mode, which is wrong, because we just copy the data
and may select a different PEB and re-try this. This patch
fixes WL worker's behavior.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 2e4d6bf..048a606 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -949,10 +949,14 @@
* This function copies logical eraseblock from physical eraseblock @from to
* physical eraseblock @to. The @vid_hdr buffer may be changed by this
* function. Returns:
- * o %0 in case of success;
- * o %1 if the operation was canceled and should be tried later (e.g.,
- * because a bit-flip was detected at the target PEB);
- * o %2 if the volume is being deleted and this LEB should not be moved.
+ * o %0 in case of success;
+ * o %1 if the operation was canceled because the volume is being deleted
+ * or because the PEB was put meanwhile;
+ * o %2 if the operation was canceled because there was a write error to the
+ * target PEB;
+ * o %-EAGAIN if the operation was canceled because a bit-flip was detected
+ * in the target PEB;
+ * o a negative error code in case of failure.
*/
int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
struct ubi_vid_hdr *vid_hdr)
@@ -978,7 +982,7 @@
/*
* Note, we may race with volume deletion, which means that the volume
* this logical eraseblock belongs to might be being deleted. Since the
- * volume deletion unmaps all the volume's logical eraseblocks, it will
+ * volume deletion un-maps all the volume's logical eraseblocks, it will
* be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
*/
vol = ubi->volumes[idx];
@@ -986,7 +990,7 @@
/* No need to do further work, cancel */
dbg_eba("volume %d is being removed, cancel", vol_id);
spin_unlock(&ubi->volumes_lock);
- return 2;
+ return 1;
}
spin_unlock(&ubi->volumes_lock);
@@ -1023,7 +1027,7 @@
/*
* OK, now the LEB is locked and we can safely start moving it. Since
- * this function utilizes thie @ubi->peb1_buf buffer which is shared
+ * this function utilizes the @ubi->peb1_buf buffer which is shared
* with some other functions, so lock the buffer by taking the
* @ubi->buf_mutex.
*/
@@ -1068,8 +1072,11 @@
vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
err = ubi_io_write_vid_hdr(ubi, to, vid_hdr);
- if (err)
+ if (err) {
+ if (err == -EIO)
+ err = 2;
goto out_unlock_buf;
+ }
cond_resched();
@@ -1079,14 +1086,17 @@
if (err != UBI_IO_BITFLIPS)
ubi_warn("cannot read VID header back from PEB %d", to);
else
- err = 1;
+ err = -EAGAIN;
goto out_unlock_buf;
}
if (data_size > 0) {
err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size);
- if (err)
+ if (err) {
+ if (err == -EIO)
+ err = 2;
goto out_unlock_buf;
+ }
cond_resched();
@@ -1101,15 +1111,16 @@
ubi_warn("cannot read data back from PEB %d",
to);
else
- err = 1;
+ err = -EAGAIN;
goto out_unlock_buf;
}
cond_resched();
if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) {
- ubi_warn("read data back from PEB %d - it is different",
- to);
+ ubi_warn("read data back from PEB %d and it is "
+ "different", to);
+ err = -EINVAL;
goto out_unlock_buf;
}
}
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 442099d..abf65ea 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -738,7 +738,7 @@
static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
int cancel)
{
- int err, scrubbing = 0;
+ int err, scrubbing = 0, torture = 0;
struct ubi_wl_prot_entry *uninitialized_var(pe);
struct ubi_wl_entry *e1, *e2;
struct ubi_vid_hdr *vid_hdr;
@@ -842,20 +842,26 @@
err = ubi_eba_copy_leb(ubi, e1->pnum, e2->pnum, vid_hdr);
if (err) {
-
+ if (err == -EAGAIN)
+ goto out_not_moved;
if (err < 0)
goto out_error;
- if (err == 1)
+ if (err == 2) {
+ /* Target PEB write error, torture it */
+ torture = 1;
goto out_not_moved;
+ }
/*
- * For some reason the LEB was not moved - it might be because
- * the volume is being deleted. We should prevent this PEB from
- * being selected for wear-levelling movement for some "time",
- * so put it to the protection tree.
+ * The LEB has not been moved because the volume is being
+ * deleted or the PEB has been put meanwhile. We should prevent
+ * this PEB from being selected for wear-leveling movement
+ * again, so put it to the protection tree.
*/
- dbg_wl("cancelled moving PEB %d", e1->pnum);
+ dbg_wl("canceled moving PEB %d", e1->pnum);
+ ubi_assert(err == 1);
+
pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_NOFS);
if (!pe) {
err = -ENOMEM;
@@ -920,9 +926,10 @@
/*
* For some reasons the LEB was not moved, might be an error, might be
* something else. @e1 was not changed, so return it back. @e2 might
- * be changed, schedule it for erasure.
+ * have been changed, schedule it for erasure.
*/
out_not_moved:
+ dbg_wl("canceled moving PEB %d", e1->pnum);
ubi_free_vid_hdr(ubi, vid_hdr);
vid_hdr = NULL;
spin_lock(&ubi->wl_lock);
@@ -930,12 +937,13 @@
wl_tree_add(e1, &ubi->scrub);
else
wl_tree_add(e1, &ubi->used);
+ ubi_assert(!ubi->move_to_put);
ubi->move_from = ubi->move_to = NULL;
- ubi->move_to_put = ubi->wl_scheduled = 0;
+ ubi->wl_scheduled = 0;
spin_unlock(&ubi->wl_lock);
e1 = NULL;
- err = schedule_erase(ubi, e2, 0);
+ err = schedule_erase(ubi, e2, torture);
if (err)
goto out_error;
@@ -1324,7 +1332,7 @@
up_write(&ubi->work_sem);
/*
- * And in case last was the WL worker and it cancelled the LEB
+ * And in case last was the WL worker and it canceled the LEB
* movement, flush again.
*/
while (ubi->works_count) {