ubi: fastmap: Fix missed ec updating after erasing old fastmap data block

After running fsstress on ubifs for a long time, UBI(16384 blocks,
fastmap takes 2 blocks) has an erase block with different erase
counters displayed from two views:

From ubiscan view: PEB 8031 has erase counter 31581
=========================================================
from              to     count      min      avg      max
---------------------------------------------------------
0        ..        9:        0        0        0        0
10       ..       99:        0        0        0        0
100      ..      999:    16383      290      315      781
1000     ..     9999:        0        0        0        0
10000    ..    99999:        1    31581    31581    31581
100000   ..      inf:        0        0        0        0
---------------------------------------------------------
Total               :    16384      290      317    31581

From detailed_erase_block_info view: PEB 8031 has erase counter 7
physical_block_number   erase_count
8030                    421
8031                    7   # mem info is different from disk info
8032                    434
8033                    425
8034                    431

Following process missed updating erase counter in wl_entry(in memory):
ubi_update_fastmap
 for (i = 1; i < new_fm->used_blocks; i++) // update fastmap data
  if (!tmp_e)
   if (old_fm && old_fm->e[i])
    erase_block(ubi, old_fm->e[i]->pnum)
     ret = ubi_io_sync_erase(ubi, pnum, 0)
     ec = be64_to_cpu(ec_hdr->ec)
     ec += ret
     ec_hdr->ec = cpu_to_be64(ec)
     ubi_io_write_ec_hdr(ubi, pnum, ec_hdr)  // ec is updated on flash
   // ec is not updated in old_fm->e[i] (in memory)

Fix it by passing wl_enter into erase_block() and updating erase
counter in erase_block().

Fixes: dbb7d2a88d2a ("UBI: Add fastmap core")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
1 file changed