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mirror of git://projects.qi-hardware.com/openwrt-xburst.git synced 2024-12-11 11:30:37 +02:00
openwrt-xburst/target/linux/generic/patches-2.6.39/441-block2mtd_refresh.patch

292 lines
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--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -30,6 +30,8 @@ struct block2mtd_dev {
struct block_device *blkdev;
struct mtd_info mtd;
struct mutex write_mutex;
+ rwlock_t bdev_mutex;
+ char devname[0];
};
@@ -82,6 +84,12 @@ static int block2mtd_erase(struct mtd_in
size_t len = instr->len;
int err;
+ read_lock(&dev->bdev_mutex);
+ if (!dev->blkdev) {
+ err = -EINVAL;
+ goto done;
+ }
+
instr->state = MTD_ERASING;
mutex_lock(&dev->write_mutex);
err = _block2mtd_erase(dev, from, len);
@@ -93,6 +101,10 @@ static int block2mtd_erase(struct mtd_in
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
+
+done:
+ read_unlock(&dev->bdev_mutex);
+
return err;
}
@@ -104,10 +116,14 @@ static int block2mtd_read(struct mtd_inf
struct page *page;
int index = from >> PAGE_SHIFT;
int offset = from & (PAGE_SIZE-1);
- int cpylen;
+ int cpylen, err = 0;
+
+ read_lock(&dev->bdev_mutex);
+ if (!dev->blkdev || (from > mtd->size)) {
+ err = -EINVAL;
+ goto done;
+ }
- if (from > mtd->size)
- return -EINVAL;
if (from + len > mtd->size)
len = mtd->size - from;
@@ -122,10 +138,14 @@ static int block2mtd_read(struct mtd_inf
len = len - cpylen;
page = page_read(dev->blkdev->bd_inode->i_mapping, index);
- if (!page)
- return -ENOMEM;
- if (IS_ERR(page))
- return PTR_ERR(page);
+ if (!page) {
+ err = -ENOMEM;
+ goto done;
+ }
+ if (IS_ERR(page)) {
+ err = PTR_ERR(page);
+ goto done;
+ }
memcpy(buf, page_address(page) + offset, cpylen);
page_cache_release(page);
@@ -136,7 +156,10 @@ static int block2mtd_read(struct mtd_inf
offset = 0;
index++;
}
- return 0;
+
+done:
+ read_unlock(&dev->bdev_mutex);
+ return err;
}
@@ -188,12 +211,22 @@ static int block2mtd_write(struct mtd_in
size_t *retlen, const u_char *buf)
{
struct block2mtd_dev *dev = mtd->priv;
- int err;
+ int err = 0;
+
+ read_lock(&dev->bdev_mutex);
+ if (!dev->blkdev) {
+ err = -EINVAL;
+ goto done;
+ }
if (!len)
- return 0;
- if (to >= mtd->size)
- return -ENOSPC;
+ goto done;
+
+ if (to >= mtd->size) {
+ err = -ENOSPC;
+ goto done;
+ }
+
if (to + len > mtd->size)
len = mtd->size - to;
@@ -202,6 +235,9 @@ static int block2mtd_write(struct mtd_in
mutex_unlock(&dev->write_mutex);
if (err > 0)
err = 0;
+
+done:
+ read_unlock(&dev->bdev_mutex);
return err;
}
@@ -210,33 +246,110 @@ static int block2mtd_write(struct mtd_in
static void block2mtd_sync(struct mtd_info *mtd)
{
struct block2mtd_dev *dev = mtd->priv;
+ read_lock(&dev->bdev_mutex);
+ if (dev->blkdev)
sync_blockdev(dev->blkdev);
+ read_unlock(&dev->bdev_mutex);
+
return;
}
+static int _open_bdev(struct block2mtd_dev *dev)
+{
+ const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
+ struct block_device *bdev;
+
+ /* Get a handle on the device */
+ bdev = blkdev_get_by_path(dev->devname, mode, dev);
+#ifndef MODULE
+ if (IS_ERR(bdev)) {
+ dev_t devt;
+
+ /* We might not have rootfs mounted at this point. Try
+ to resolve the device name by other means. */
+
+ devt = name_to_dev_t(dev->devname);
+ if (devt)
+ bdev = blkdev_get_by_dev(devt, mode, dev);
+ }
+#endif
+
+ if (IS_ERR(bdev)) {
+ ERROR("error: cannot open device %s", dev->devname);
+ return 1;
+ }
+ dev->blkdev = bdev;
+
+ if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
+ ERROR("attempting to use an MTD device as a block device");
+ return 1;
+ }
+
+ return 0;
+}
+
+static void _close_bdev(struct block2mtd_dev *dev)
+{
+ struct block_device *bdev;
+
+ if (!dev->blkdev)
+ return;
+
+ bdev = dev->blkdev;
+ invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping, 0, -1);
+ blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
+ dev->blkdev = NULL;
+}
+
static void block2mtd_free_device(struct block2mtd_dev *dev)
{
if (!dev)
return;
kfree(dev->mtd.name);
-
- if (dev->blkdev) {
- invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
- 0, -1);
- blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
- }
-
+ _close_bdev(dev);
kfree(dev);
}
-/* FIXME: ensure that mtd->size % erase_size == 0 */
-static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
+static int block2mtd_refresh(struct mtd_info *mtd)
{
- const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
+ struct block2mtd_dev *dev = mtd->priv;
struct block_device *bdev;
+ dev_t devt;
+ int err = 0;
+
+ /* no other mtd function can run at this point */
+ write_lock(&dev->bdev_mutex);
+
+ /* get the device number for the whole disk */
+ devt = MKDEV(MAJOR(dev->blkdev->bd_dev), 0);
+
+ /* close the old block device */
+ _close_bdev(dev);
+
+ /* open the whole disk, issue a partition rescan, then */
+ bdev = blkdev_get_by_dev(devt, FMODE_WRITE | FMODE_READ, mtd);
+ if (!bdev || !bdev->bd_disk)
+ err = -EINVAL;
+#ifndef CONFIG_MTD_BLOCK2MTD_MODULE
+ else
+ err = rescan_partitions(bdev->bd_disk, bdev);
+#endif
+ if (bdev)
+ blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
+
+ /* try to open the partition block device again */
+ _open_bdev(dev);
+ write_unlock(&dev->bdev_mutex);
+
+ return err;
+}
+
+/* FIXME: ensure that mtd->size % erase_size == 0 */
+static struct block2mtd_dev *add_device(char *devname, int erase_size, char *mtdname)
+{
struct block2mtd_dev *dev;
struct mtd_partition *part;
char *name;
@@ -244,36 +357,17 @@ static struct block2mtd_dev *add_device(
if (!devname)
return NULL;
- dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
+ dev = kzalloc(sizeof(struct block2mtd_dev) + strlen(devname) + 1, GFP_KERNEL);
if (!dev)
return NULL;
- /* Get a handle on the device */
- bdev = blkdev_get_by_path(devname, mode, dev);
-#ifndef MODULE
- if (IS_ERR(bdev)) {
-
- /* We might not have rootfs mounted at this point. Try
- to resolve the device name by other means. */
+ strcpy(dev->devname, devname);
- dev_t devt = name_to_dev_t(devname);
- if (devt)
- bdev = blkdev_get_by_dev(devt, mode, dev);
- }
-#endif
-
- if (IS_ERR(bdev)) {
- ERROR("error: cannot open device %s", devname);
+ if (_open_bdev(dev))
goto devinit_err;
- }
- dev->blkdev = bdev;
-
- if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
- ERROR("attempting to use an MTD device as a block device");
- goto devinit_err;
- }
mutex_init(&dev->write_mutex);
+ rwlock_init(&dev->bdev_mutex);
/* Setup the MTD structure */
/* make the name contain the block device in */
@@ -298,6 +392,7 @@ static struct block2mtd_dev *add_device(
dev->mtd.read = block2mtd_read;
dev->mtd.priv = dev;
dev->mtd.owner = THIS_MODULE;
+ dev->mtd.refresh_device = block2mtd_refresh;
part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
part->name = name;