[PATCH RFC v3 for-6.8/block 04/17] mtd: block2mtd: use bdev apis

Yu Kuai
2023-12-21T08:59:22Z

From: Yu Kuai <yukuai3@huawei.com>

On the one hand covert to use folio while reading bdev inode, on the
other hand prevent to access bd_inode directly.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
drivers/mtd/devices/block2mtd.c | 81 +++++++++++++++------------------
1 file changed, 36 insertions(+), 45 deletions(-)

diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index aa44a23ec045..cf201bf73184 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -46,40 +46,34 @@ struct block2mtd_dev {
/* Static info about the MTD, used in cleanup_module */
static LIST_HEAD(blkmtd_device_list);

-
-static struct page *page_read(struct address_space *mapping, pgoff_t index)
-{
- return read_mapping_page(mapping, index, NULL);
-}
-
/* erase a specified part of the device */
static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
{
- struct address_space *mapping =
- dev->bdev_handle->bdev->bd_inode->i_mapping;
- struct page *page;
+ struct block_device *bdev = dev->bdev_handle->bdev;
+ struct folio *folio;
pgoff_t index = to >> PAGE_SHIFT; // page index
int pages = len >> PAGE_SHIFT;
u_long *p;
u_long *max;

while (pages) {
- page = page_read(mapping, index);
- if (IS_ERR(page))
- return PTR_ERR(page);
+ folio = bdev_read_folio(bdev, index << PAGE_SHIFT);
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);

- max = page_address(page) + PAGE_SIZE;
- for (p=page_address(page); p<max; p++)
+ max = folio_address(folio) + folio_size(folio);
+ for (p = folio_address(folio); p < max; p++)
if (*p != -1UL) {
- lock_page(page);
- memset(page_address(page), 0xff, PAGE_SIZE);
- set_page_dirty(page);
- unlock_page(page);
- balance_dirty_pages_ratelimited(mapping);
+ folio_lock(folio);
+ memset(folio_address(folio), 0xff,
+ folio_size(folio));
+ folio_mark_dirty(folio);
+ folio_unlock(folio);
+ bdev_balance_dirty_pages_ratelimited(bdev);
break;
}

- put_page(page);
+ folio_put(folio);
pages--;
index++;
}
@@ -106,9 +100,7 @@ static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
struct block2mtd_dev *dev = mtd->priv;
- struct address_space *mapping =
- dev->bdev_handle->bdev->bd_inode->i_mapping;
- struct page *page;
+ struct folio *folio;
pgoff_t index = from >> PAGE_SHIFT;
int offset = from & (PAGE_SIZE-1);
int cpylen;
@@ -120,12 +112,13 @@ static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
cpylen = len; // this page
len = len - cpylen;

- page = page_read(mapping, index);
- if (IS_ERR(page))
- return PTR_ERR(page);
+ folio = bdev_read_folio(dev->bdev_handle->bdev,
+ index << PAGE_SHIFT);
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);

- memcpy(buf, page_address(page) + offset, cpylen);
- put_page(page);
+ memcpy(buf, folio_address(folio) + offset, cpylen);
+ folio_put(folio);

if (retlen)
*retlen += cpylen;
@@ -141,9 +134,8 @@ static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
loff_t to, size_t len, size_t *retlen)
{
- struct page *page;
- struct address_space *mapping =
- dev->bdev_handle->bdev->bd_inode->i_mapping;
+ struct block_device *bdev = dev->bdev_handle->bdev;
+ struct folio *folio;
pgoff_t index = to >> PAGE_SHIFT; // page index
int offset = to & ~PAGE_MASK; // page offset
int cpylen;
@@ -155,18 +147,18 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
cpylen = len; // this page
len = len - cpylen;

- page = page_read(mapping, index);
- if (IS_ERR(page))
- return PTR_ERR(page);
+ folio = bdev_read_folio(bdev, index << PAGE_SHIFT);
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);

- if (memcmp(page_address(page)+offset, buf, cpylen)) {
- lock_page(page);
- memcpy(page_address(page) + offset, buf, cpylen);
- set_page_dirty(page);
- unlock_page(page);
- balance_dirty_pages_ratelimited(mapping);
+ if (memcmp(folio_address(folio) + offset, buf, cpylen)) {
+ folio_lock(folio);
+ memcpy(folio_address(folio) + offset, buf, cpylen);
+ folio_mark_dirty(folio);
+ folio_unlock(folio);
+ bdev_balance_dirty_pages_ratelimited(bdev);
}
- put_page(page);
+ folio_put(folio);

if (retlen)
*retlen += cpylen;
@@ -211,8 +203,7 @@ static void block2mtd_free_device(struct block2mtd_dev *dev)
kfree(dev->mtd.name);

if (dev->bdev_handle) {
- invalidate_mapping_pages(
- dev->bdev_handle->bdev->bd_inode->i_mapping, 0, -1);
+ invalidate_bdev(dev->bdev_handle->bdev);
bdev_release(dev->bdev_handle);
}

@@ -295,7 +286,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size,
goto err_free_block2mtd;
}

- if ((long)bdev->bd_inode->i_size % erase_size) {
+ if (bdev_nr_bytes(bdev) % erase_size) {
pr_err("erasesize must be a divisor of device size\n");
goto err_free_block2mtd;
}
@@ -313,7 +304,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size,

dev->mtd.name = name;

- dev->mtd.size = bdev->bd_inode->i_size & PAGE_MASK;
+ dev->mtd.size = bdev_nr_bytes(bdev) & PAGE_MASK;
dev->mtd.erasesize = erase_size;
dev->mtd.writesize = 1;
dev->mtd.writebufsize = PAGE_SIZE;
--
2.39.2