target/linux/generic/pending-4.9/494-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 diff --git a/drivers/mtd/ubi/attach.c b/drivers/mtd/ubi/attach.c
  11 index 93ceea4f27d5..a4f849d69104 100644
  12 --- a/drivers/mtd/ubi/attach.c
  13 +++ b/drivers/mtd/ubi/attach.c
  14 @@ -939,6 +939,13 @@ static bool vol_ignored(int vol_id)
  15  #endif
  16  }
  17
  18 +static bool ec_hdr_has_eof(struct ubi_ec_hdr *ech)
  19 +{
  20 +       return ech->padding1[0] == 'E' &&
  21 +              ech->padding1[1] == 'O' &&
  22 +              ech->padding1[2] == 'F';
  23 +}
  24 +
  25  /**
  26   * scan_peb - scan and process UBI headers of a PEB.
  27   * @ubi: UBI device description object
  28 @@ -971,9 +978,21 @@ static int scan_peb(struct ubi_device *ubi, struct ubi_attach_info *ai,
  29                 return 0;
  30         }
  31
  32 -       err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
  33 -       if (err < 0)
  34 -               return err;
  35 +       if (!ai->eof_found) {
  36 +               err = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
  37 +               if (err < 0)
  38 +                       return err;
  39 +
  40 +               if (ec_hdr_has_eof(ech)) {
  41 +                       pr_notice("UBI: EOF marker found, PEBs from %d will be erased",
  42 +                               pnum);
  43 +                       ai->eof_found = true;
  44 +               }
  45 +       }
  46 +
  47 +       if (ai->eof_found)
  48 +               err = UBI_IO_FF_BITFLIPS;
  49 +
  50         switch (err) {
  51         case 0:
  52                 break;
  53 diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
  54 index 697dbcba7371..92d207ff2458 100644
  55 --- a/drivers/mtd/ubi/ubi.h
  56 +++ b/drivers/mtd/ubi/ubi.h
  57 @@ -779,6 +779,7 @@ struct ubi_attach_info {
  58         int mean_ec;
  59         uint64_t ec_sum;
  60         int ec_count;
  61 +       bool eof_found;
  62         struct kmem_cache *aeb_slab_cache;
  63         struct ubi_ec_hdr *ech;
  64         struct ubi_vid_io_buf *vidb;
  65 --
  66 2.11.0
  67