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 --- a/include/uapi/mtd/ubi-user.h
  20 +++ b/include/uapi/mtd/ubi-user.h
  21 @@ -138,9 +138,12 @@
  22   * Block devices on UBI volumes
  23   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24   *
  25 - * To create or remove a R/O block device on top of an UBI volume the
  26 - * %UBI_IOCVOLCRBLK and %UBI_IOCVOLRMBLK ioctl commands should be used,
  27 - * respectively. These commands take no arguments.
  28 + * To create a R/O block device on top of an UBI volume the %UBI_IOCVOLCRBLK
  29 + * should be used. A pointer to a &struct ubi_blkcreate_req object is expected
  30 + * to be passed, which is not used and reserved for future usage.
  31 + *
  32 + * Conversely, to remove a block device the %UBI_IOCVOLRMBLK should be used,
  33 + * which takes no arguments.
  34   */
  35
  36  /*
  37 @@ -199,7 +202,7 @@
  38  #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \
  39                                struct ubi_set_vol_prop_req)
  40  /* Create a R/O block device on top of an UBI volume */
  41 -#define UBI_IOCVOLCRBLK _IO(UBI_VOL_IOC_MAGIC, 7)
  42 +#define UBI_IOCVOLCRBLK _IOW(UBI_VOL_IOC_MAGIC, 7, struct ubi_blkcreate_req)
  43  /* Remove the R/O block device */
  44  #define UBI_IOCVOLRMBLK _IO(UBI_VOL_IOC_MAGIC, 8)
  45
  46 @@ -431,4 +434,12 @@ struct ubi_set_vol_prop_req {
  47         __u64 value;
  48  }  __packed;
  49
  50 +/**
  51 + * struct ubi_blkcreate_req - a data structure used in block creation requests.
  52 + * @padding: reserved for future, not used, has to be zeroed
  53 + */
  54 +struct ubi_blkcreate_req {
  55 +       __s8  padding[128];
  56 +}  __packed;
  57 +
  58  #endif /* __UBI_USER_H__ */