target/linux/generic/patches-3.9/441-block2mtd_refresh.patch

   1 --- a/drivers/mtd/devices/block2mtd.c
   2 +++ b/drivers/mtd/devices/block2mtd.c
   3 @@ -29,6 +29,8 @@ struct block2mtd_dev {
   4         struct block_device *blkdev;
   5         struct mtd_info mtd;
   6         struct mutex write_mutex;
   7 +       rwlock_t bdev_mutex;
   8 +       char devname[0];
   9  };
  10
  11
  12 @@ -80,6 +82,12 @@ static int block2mtd_erase(struct mtd_in
  13         size_t len = instr->len;
  14         int err;
  15
  16 +       read_lock(&dev->bdev_mutex);
  17 +       if (!dev->blkdev) {
  18 +               err = -EINVAL;
  19 +               goto done;
  20 +       }
  21 +
  22         instr->state = MTD_ERASING;
  23         mutex_lock(&dev->write_mutex);
  24         err = _block2mtd_erase(dev, from, len);
  25 @@ -91,6 +99,10 @@ static int block2mtd_erase(struct mtd_in
  26                 instr->state = MTD_ERASE_DONE;
  27
  28         mtd_erase_callback(instr);
  29 +
  30 +done:
  31 +       read_unlock(&dev->bdev_mutex);
  32 +
  33         return err;
  34  }
  35
  36 @@ -102,7 +114,13 @@ static int block2mtd_read(struct mtd_inf
  37         struct page *page;
  38         int index = from >> PAGE_SHIFT;
  39         int offset = from & (PAGE_SIZE-1);
  40 -       int cpylen;
  41 +       int cpylen, err = 0;
  42 +
  43 +       read_lock(&dev->bdev_mutex);
  44 +       if (!dev->blkdev || (from > mtd->size)) {
  45 +               err = -EINVAL;
  46 +               goto done;
  47 +       }
  48
  49         while (len) {
  50                 if ((offset + len) > PAGE_SIZE)
  51 @@ -112,8 +130,10 @@ static int block2mtd_read(struct mtd_inf
  52                 len = len - cpylen;
  53
  54                 page = page_read(dev->blkdev->bd_inode->i_mapping, index);
  55 -               if (IS_ERR(page))
  56 -                       return PTR_ERR(page);
  57 +               if (IS_ERR(page)) {
  58 +                       err = PTR_ERR(page);
  59 +                       goto done;
  60 +               }
  61
  62                 memcpy(buf, page_address(page) + offset, cpylen);
  63                 page_cache_release(page);
  64 @@ -124,7 +144,10 @@ static int block2mtd_read(struct mtd_inf
  65                 offset = 0;
  66                 index++;
  67         }
  68 -       return 0;
  69 +
  70 +done:
  71 +       read_unlock(&dev->bdev_mutex);
  72 +       return err;
  73  }
  74
  75
  76 @@ -173,13 +196,22 @@ static int block2mtd_write(struct mtd_in
  77                 size_t *retlen, const u_char *buf)
  78  {
  79         struct block2mtd_dev *dev = mtd->priv;
  80 -       int err;
  81 +       int err = 0;
  82 +
  83 +       read_lock(&dev->bdev_mutex);
  84 +       if (!dev->blkdev) {
  85 +               err = -EINVAL;
  86 +               goto done;
  87 +       }
  88
  89         mutex_lock(&dev->write_mutex);
  90         err = _block2mtd_write(dev, buf, to, len, retlen);
  91         mutex_unlock(&dev->write_mutex);
  92         if (err > 0)
  93                 err = 0;
  94 +
  95 +done:
  96 +       read_unlock(&dev->bdev_mutex);
  97         return err;
  98  }
  99
 100 @@ -188,33 +220,110 @@ static int block2mtd_write(struct mtd_in
 101  static void block2mtd_sync(struct mtd_info *mtd)
 102  {
 103         struct block2mtd_dev *dev = mtd->priv;
 104 +       read_lock(&dev->bdev_mutex);
 105 +       if (dev->blkdev)
 106         sync_blockdev(dev->blkdev);
 107 +       read_unlock(&dev->bdev_mutex);
 108 +
 109         return;
 110  }
 111
 112
 113 +static int _open_bdev(struct block2mtd_dev *dev)
 114 +{
 115 +       const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
 116 +       struct block_device *bdev;
 117 +
 118 +       /* Get a handle on the device */
 119 +       bdev = blkdev_get_by_path(dev->devname, mode, dev);
 120 +#ifndef MODULE
 121 +       if (IS_ERR(bdev)) {
 122 +               dev_t devt;
 123 +
 124 +               /* We might not have rootfs mounted at this point. Try
 125 +                  to resolve the device name by other means. */
 126 +
 127 +               devt = name_to_dev_t(dev->devname);
 128 +               if (devt)
 129 +                       bdev = blkdev_get_by_dev(devt, mode, dev);
 130 +       }
 131 +#endif
 132 +
 133 +       if (IS_ERR(bdev)) {
 134 +               ERROR("error: cannot open device %s", dev->devname);
 135 +               return 1;
 136 +       }
 137 +       dev->blkdev = bdev;
 138 +
 139 +       if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
 140 +               ERROR("attempting to use an MTD device as a block device");
 141 +               return 1;
 142 +       }
 143 +
 144 +       return 0;
 145 +}
 146 +
 147 +static void _close_bdev(struct block2mtd_dev *dev)
 148 +{
 149 +       struct block_device *bdev;
 150 +
 151 +       if (!dev->blkdev)
 152 +               return;
 153 +
 154 +       bdev = dev->blkdev;
 155 +       invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
 156 +       blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 157 +       dev->blkdev = NULL;
 158 +}
 159 +
 160  static void block2mtd_free_device(struct block2mtd_dev *dev)
 161  {
 162         if (!dev)
 163                 return;
 164
 165         kfree(dev->mtd.name);
 166 -
 167 -       if (dev->blkdev) {
 168 -               invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
 169 -                                       0, -1);
 170 -               blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 171 -       }
 172 -
 173 +       _close_bdev(dev);
 174         kfree(dev);
 175  }
 176
 177
 178 -/* FIXME: ensure that mtd->size % erase_size == 0 */
 179 -static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
 180 +static int block2mtd_refresh(struct mtd_info *mtd)
 181  {
 182 -       const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
 183 +       struct block2mtd_dev *dev = mtd->priv;
 184         struct block_device *bdev;
 185 +       dev_t devt;
 186 +       int err = 0;
 187 +
 188 +       /* no other mtd function can run at this point */
 189 +       write_lock(&dev->bdev_mutex);
 190 +
 191 +       /* get the device number for the whole disk */
 192 +       devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
 193 +
 194 +       /* close the old block device */
 195 +       _close_bdev(dev);
 196 +
 197 +       /* open the whole disk, issue a partition rescan, then */
 198 +       bdev = blkdev_get_by_dev(devt, FMODE_WRITE | FMODE_READ, mtd);
 199 +       if (!bdev || !bdev->bd_disk)
 200 +               err = -EINVAL;
 201 +#ifndef CONFIG_MTD_BLOCK2MTD_MODULE
 202 +       else
 203 +               err = rescan_partitions(bdev->bd_disk, bdev);
 204 +#endif
 205 +       if (bdev)
 206 +               blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 207 +
 208 +       /* try to open the partition block device again */
 209 +       _open_bdev(dev);
 210 +       write_unlock(&dev->bdev_mutex);
 211 +
 212 +       return err;
 213 +}
 214 +
 215 +/* FIXME: ensure that mtd->size % erase_size == 0 */
 216 +static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
 217 +{
 218         struct block2mtd_dev *dev;
 219         struct mtd_partition *part;
 220         char *name;
 221 @@ -222,36 +331,17 @@ static struct block2mtd_dev *add_device(
 222         if (!devname)
 223                 return NULL;
 224
 225 -       dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
 226 +       dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
 227         if (!dev)
 228                 return NULL;
 229
 230 -       /* Get a handle on the device */
 231 -       bdev = blkdev_get_by_path(devname, mode, dev);
 232 -#ifndef MODULE
 233 -       if (IS_ERR(bdev)) {
 234 -
 235 -               /* We might not have rootfs mounted at this point. Try
 236 -                  to resolve the device name by other means. */
 237 -
 238 -               dev_t devt = name_to_dev_t(devname);
 239 -               if (devt)
 240 -                       bdev = blkdev_get_by_dev(devt, mode, dev);
 241 -       }
 242 -#endif
 243 -
 244 -       if (IS_ERR(bdev)) {
 245 -               ERROR("error: cannot open device %s", devname);
 246 -               goto devinit_err;
 247 -       }
 248 -       dev->blkdev = bdev;
 249 +       strcpy(dev->devname, devname);
 250
 251 -       if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
 252 -               ERROR("attempting to use an MTD device as a block device");
 253 +       if (_open_bdev(dev))
 254                 goto devinit_err;
 255 -       }
 256
 257         mutex_init(&dev->write_mutex);
 258 +       rwlock_init(&dev->bdev_mutex);
 259
 260         /* Setup the MTD structure */
 261         /* make the name contain the block device in */
 262 @@ -276,6 +366,7 @@ static struct block2mtd_dev *add_device(
 263         dev->mtd._read = block2mtd_read;
 264         dev->mtd.priv = dev;
 265         dev->mtd.owner = THIS_MODULE;
 266 +       dev->mtd.refresh_device = block2mtd_refresh;
 267
 268         part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
 269         part->name = name;