target/linux/generic/backport-4.9/068-v4.18-0001-mtd-move-code-adding-registering-partitions-to-the-p.patch

   1 From 5ac67ce36cfe38b4c104a42ce52c5c8d526f1c95 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   3 Date: Tue, 27 Mar 2018 22:35:41 +0200
   4 Subject: [PATCH] mtd: move code adding (registering) partitions to the
   5  parse_mtd_partitions()
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 This commit slightly simplifies the code. Every parse_mtd_partitions()
  11 caller (out of two existing ones) had to add partitions & cleanup parser
  12 on its own. This moves that responsibility into the function.
  13
  14 That change also allows dropping struct mtd_partitions argument.
  15
  16 There is one minor behavior change caused by this cleanup. If
  17 parse_mtd_partitions() fails to add partitions (add_mtd_partitions()
  18 return an error) then mtd_device_parse_register() will still try to
  19 add (register) fallback partitions. It's a real corner case affecting
  20 one of uncommon error paths and shouldn't cause any harm.
  21
  22 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  23 Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
  24 ---
  25  drivers/mtd/mtdcore.c | 14 ++++----------
  26  drivers/mtd/mtdcore.h |  1 -
  27  drivers/mtd/mtdpart.c | 44 ++++++++++++++++----------------------------
  28  3 files changed, 20 insertions(+), 39 deletions(-)
  29
  30 --- a/drivers/mtd/mtdcore.c
  31 +++ b/drivers/mtd/mtdcore.c
  32 @@ -676,7 +676,6 @@ int mtd_device_parse_register(struct mtd
  33                               const struct mtd_partition *parts,
  34                               int nr_parts)
  35  {
  36 -       struct mtd_partitions parsed = { };
  37         int ret;
  38
  39         mtd_set_dev_defaults(mtd);
  40 @@ -688,13 +687,10 @@ int mtd_device_parse_register(struct mtd
  41         }
  42
  43         /* Prefer parsed partitions over driver-provided fallback */
  44 -       ret = parse_mtd_partitions(mtd, types, &parsed, parser_data);
  45 -       if (!ret && parsed.nr_parts) {
  46 -               parts = parsed.parts;
  47 -               nr_parts = parsed.nr_parts;
  48 -       }
  49 -
  50 -       if (nr_parts)
  51 +       ret = parse_mtd_partitions(mtd, types, parser_data);
  52 +       if (ret > 0)
  53 +               ret = 0;
  54 +       else if (nr_parts)
  55                 ret = add_mtd_partitions(mtd, parts, nr_parts);
  56         else if (!device_is_registered(&mtd->dev))
  57                 ret = add_mtd_device(mtd);
  58 @@ -720,8 +716,6 @@ int mtd_device_parse_register(struct mtd
  59         }
  60
  61  out:
  62 -       /* Cleanup any parsed partitions */
  63 -       mtd_part_parser_cleanup(&parsed);
  64         if (ret && device_is_registered(&mtd->dev))
  65                 del_mtd_device(mtd);
  66
  67 --- a/drivers/mtd/mtdcore.h
  68 +++ b/drivers/mtd/mtdcore.h
  69 @@ -14,7 +14,6 @@ int del_mtd_partitions(struct mtd_info *
  70  struct mtd_partitions;
  71
  72  int parse_mtd_partitions(struct mtd_info *master, const char * const *types,
  73 -                        struct mtd_partitions *pparts,
  74                          struct mtd_part_parser_data *data);
  75
  76  void mtd_part_parser_cleanup(struct mtd_partitions *parts);
  77 --- a/drivers/mtd/mtdpart.c
  78 +++ b/drivers/mtd/mtdpart.c
  79 @@ -383,20 +383,7 @@ static inline void free_partition(struct
  80   */
  81  static int mtd_parse_part(struct mtd_part *slave, const char *const *types)
  82  {
  83 -       struct mtd_partitions parsed;
  84 -       int err;
  85 -
  86 -       err = parse_mtd_partitions(&slave->mtd, types, &parsed, NULL);
  87 -       if (err)
  88 -               return err;
  89 -       else if (!parsed.nr_parts)
  90 -               return -ENOENT;
  91 -
  92 -       err = add_mtd_partitions(&slave->mtd, parsed.parts, parsed.nr_parts);
  93 -
  94 -       mtd_part_parser_cleanup(&parsed);
  95 -
  96 -       return err;
  97 +       return parse_mtd_partitions(&slave->mtd, types, NULL);
  98  }
  99
 100  static struct mtd_part *allocate_partition(struct mtd_info *parent,
 101 @@ -973,30 +960,27 @@ static int mtd_part_of_parse(struct mtd_
 102  }
 103
 104  /**
 105 - * parse_mtd_partitions - parse MTD partitions
 106 + * parse_mtd_partitions - parse and register MTD partitions
 107 + *
 108   * @master: the master partition (describes whole MTD device)
 109   * @types: names of partition parsers to try or %NULL
 110 - * @pparts: info about partitions found is returned here
 111   * @data: MTD partition parser-specific data
 112   *
 113 - * This function tries to find partition on MTD device @master. It uses MTD
 114 - * partition parsers, specified in @types. However, if @types is %NULL, then
 115 - * the default list of parsers is used. The default list contains only the
 116 + * This function tries to find & register partitions on MTD device @master. It
 117 + * uses MTD partition parsers, specified in @types. However, if @types is %NULL,
 118 + * then the default list of parsers is used. The default list contains only the
 119   * "cmdlinepart" and "ofpart" parsers ATM.
 120   * Note: If there are more then one parser in @types, the kernel only takes the
 121   * partitions parsed out by the first parser.
 122   *
 123   * This function may return:
 124   * o a negative error code in case of failure
 125 - * o zero otherwise, and @pparts will describe the partitions, number of
 126 - *   partitions, and the parser which parsed them. Caller must release
 127 - *   resources with mtd_part_parser_cleanup() when finished with the returned
 128 - *   data.
 129 + * o number of found partitions otherwise
 130   */
 131  int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
 132 -                        struct mtd_partitions *pparts,
 133                          struct mtd_part_parser_data *data)
 134  {
 135 +       struct mtd_partitions pparts = { };
 136         struct mtd_part_parser *parser;
 137         int ret, err = 0;
 138
 139 @@ -1010,7 +994,7 @@ int parse_mtd_partitions(struct mtd_info
 140                  * handled in a separated function.
 141                  */
 142                 if (!strcmp(*types, "ofpart")) {
 143 -                       ret = mtd_part_of_parse(master, pparts);
 144 +                       ret = mtd_part_of_parse(master, &pparts);
 145                 } else {
 146                         pr_debug("%s: parsing partitions %s\n", master->name,
 147                                  *types);
 148 @@ -1021,13 +1005,17 @@ int parse_mtd_partitions(struct mtd_info
 149                                 parser ? parser->name : NULL);
 150                         if (!parser)
 151                                 continue;
 152 -                       ret = mtd_part_do_parse(parser, master, pparts, data);
 153 +                       ret = mtd_part_do_parse(parser, master, &pparts, data);
 154                         if (ret <= 0)
 155                                 mtd_part_parser_put(parser);
 156                 }
 157                 /* Found partitions! */
 158 -               if (ret > 0)
 159 -                       return 0;
 160 +               if (ret > 0) {
 161 +                       err = add_mtd_partitions(master, pparts.parts,
 162 +                                                pparts.nr_parts);
 163 +                       mtd_part_parser_cleanup(&pparts);
 164 +                       return err ? err : pparts.nr_parts;
 165 +               }
 166                 /*
 167                  * Stash the first error we see; only report it if no parser
 168                  * succeeds