target/linux/generic/pending-4.14/494-mtd-ubi-add-EOF-marker-support.patch

   1 From: Gabor Juhos <juhosg@openwrt.org>
   2 Subject: mtd: add EOF marker support to the UBI layer
   3
   4 Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
   5 ---
   6  drivers/mtd/ubi/attach.c | 25 ++++++++++++++++++++++---
   7  drivers/mtd/ubi/ubi.h    |  1 +
   8  2 files changed, 23 insertions(+), 3 deletions(-)
   9
  10 --- a/drivers/mtd/ubi/attach.c
  11 +++ b/drivers/mtd/ubi/attach.c
  12 @@ -939,6 +939,13 @@ static bool vol_ignored(int vol_id)
  13  #endif
  14  }
  15
  16 +static bool ec_hdr_has_eof(struct ubi_ec_hdr *ech)
  17 +{
  18 +       return ech->padding1[0] == 'E' &&
  19 +              ech->padding1[1] == 'O' &&
  20 +              ech->padding1[2] == 'F';
  21 +}
  22 +
  23  /**
  24   * scan_peb - scan and process UBI headers of a PEB.
  25   * @ubi: UBI device description object
  26 @@ -971,9 +978,21 @@ static int scan_peb(struct ubi_device *u
  27                 return 0;
  28         }
  29
  30 -       err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
  31 -       if (err < 0)
  32 -               return err;
  33 +       if (!ai->eof_found) {
  34 +               err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
  35 +               if (err < 0)
  36 +                       return err;
  37 +
  38 +               if (ec_hdr_has_eof(ech)) {
  39 +                       pr_notice("UBI: EOF marker found, PEBs from %d will be erased\n",
  40 +                               pnum);
  41 +                       ai->eof_found = true;
  42 +               }
  43 +       }
  44 +
  45 +       if (ai->eof_found)
  46 +               err = UBI_IO_FF_BITFLIPS;
  47 +
  48         switch (err) {
  49         case 0:
  50                 break;
  51 --- a/drivers/mtd/ubi/ubi.h
  52 +++ b/drivers/mtd/ubi/ubi.h
  53 @@ -778,6 +778,7 @@ struct ubi_attach_info {
  54         int mean_ec;
  55         uint64_t ec_sum;
  56         int ec_count;
  57 +       bool eof_found;
  58         struct kmem_cache *aeb_slab_cache;
  59         struct ubi_ec_hdr *ech;
  60         struct ubi_vid_io_buf *vidb;