target/linux/generic/patches-3.14/047-UBI-make-UBI_IOCVOLCRBLK-take-a-parameter-for-future.patch

   1 From 463c5eedb4a13b9aa91f05498a0f2c20bd03f8c4 Mon Sep 17 00:00:00 2001
   2 From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
   3 Date: Wed, 5 Mar 2014 11:16:14 -0300
   4 Subject: [PATCH] UBI: make UBI_IOCVOLCRBLK take a parameter for future usage
   5
   6 In order to allow a future ioctl parameter, such as a creation flag,
   7 we change the UBI_IOCVOLCRBLK so it accepts a struct ubi_blkcreate_req.
   8 For the time being the structure is not in use, but fully reserved.
   9
  10 This ABI change is still possible and harmless, because the ioctl has just
  11 been introduced and there's no userspace program which uses it.
  12
  13 Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
  14 Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
  15 ---
  16  include/uapi/mtd/ubi-user.h | 19 +++++++++++++++----
  17  1 file changed, 15 insertions(+), 4 deletions(-)
  18
  19 diff --git a/include/uapi/mtd/ubi-user.h b/include/uapi/mtd/ubi-user.h
  20 index 9c885e2..1927b0d 100644
  21 --- a/include/uapi/mtd/ubi-user.h
  22 +++ b/include/uapi/mtd/ubi-user.h
  23 @@ -138,9 +138,12 @@
  24   * Block devices on UBI volumes
  25   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  26   *
  27 - * To create or remove a R/O block device on top of an UBI volume the
  28 - * %UBI_IOCVOLCRBLK and %UBI_IOCVOLRMBLK ioctl commands should be used,
  29 - * respectively. These commands take no arguments.
  30 + * To create a R/O block device on top of an UBI volume the %UBI_IOCVOLCRBLK
  31 + * should be used. A pointer to a &struct ubi_blkcreate_req object is expected
  32 + * to be passed, which is not used and reserved for future usage.
  33 + *
  34 + * Conversely, to remove a block device the %UBI_IOCVOLRMBLK should be used,
  35 + * which takes no arguments.
  36   */
  37
  38  /*
  39 @@ -199,7 +202,7 @@
  40  #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \
  41                                struct ubi_set_vol_prop_req)
  42  /* Create a R/O block device on top of an UBI volume */
  43 -#define UBI_IOCVOLCRBLK _IO(UBI_VOL_IOC_MAGIC, 7)
  44 +#define UBI_IOCVOLCRBLK _IOW(UBI_VOL_IOC_MAGIC, 7, struct ubi_blkcreate_req)
  45  /* Remove the R/O block device */
  46  #define UBI_IOCVOLRMBLK _IO(UBI_VOL_IOC_MAGIC, 8)
  47
  48 @@ -431,4 +434,12 @@ struct ubi_set_vol_prop_req {
  49         __u64 value;
  50  }  __packed;
  51
  52 +/**
  53 + * struct ubi_blkcreate_req - a data structure used in block creation requests.
  54 + * @padding: reserved for future, not used, has to be zeroed
  55 + */
  56 +struct ubi_blkcreate_req {
  57 +       __s8  padding[128];
  58 +}  __packed;
  59 +
  60  #endif /* __UBI_USER_H__ */
  61 --
  62 1.9.2
  63