Re: [PATCH v2] blkdev: Replace blksize_bits() with ilog2()

From: Christoph Hellwig
Date: Fri May 29 2020 - 10:16:03 EST


> ns->size = i_size_read(ns->bdev->bd_inode);
> - ns->blksize_shift = blksize_bits(bdev_logical_block_size(ns->bdev));
> + ns->blksize_shift = ilog2(bdev_logical_block_size(ns->bdev));

This should just be:

ns->blksize_shift = ns->bdev->bd_inode->i_blkbits;

> diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
> index 777734d1b4e5..55adb134451b 100644
> --- a/drivers/s390/block/dasd_ioctl.c
> +++ b/drivers/s390/block/dasd_ioctl.c
> @@ -228,7 +228,7 @@ dasd_format(struct dasd_block *block, struct format_data_t *fdata)
> */
> if (fdata->start_unit == 0) {
> struct block_device *bdev = bdget_disk(block->gdp, 0);
> - bdev->bd_inode->i_blkbits = blksize_bits(fdata->blksize);
> + bdev->bd_inode->i_blkbits = ilog2(fdata->blksize);

This also needs to set bdev->bd_block_size, so this probably warrants
a separate fix that be backported. It might be nice to split out
a helper that sets bd_block_size and bd_inode->i_blkbits together
so that such a use is more obvious.

> } else if (inode->i_bdev) {
> blksize = bdev_logical_block_size(inode->i_bdev);
> - blkbits = blksize_bits(blksize);
> + blkbits = ilog2(blksize);

This can just use inode->i_bdev->bd_inode->i_blkbits.

> diff --git a/fs/buffer.c b/fs/buffer.c
> index fc8831c392d7..fa92e0afe349 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -907,7 +907,7 @@ static sector_t blkdev_max_block(struct block_device *bdev, unsigned int size)
> loff_t sz = i_size_read(bdev->bd_inode);
>
> if (sz) {
> - unsigned int sizebits = blksize_bits(size);
> + unsigned int sizebits = ilog2(size);

bdev->bd_inode->i_blkbits.

> diff --git a/fs/direct-io.c b/fs/direct-io.c
> index 1543b5af400e..7ea2cd3effcc 100644
> --- a/fs/direct-io.c
> +++ b/fs/direct-io.c
> @@ -1148,7 +1148,7 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
>
> if (align & blocksize_mask) {
> if (bdev)
> - blkbits = blksize_bits(bdev_logical_block_size(bdev));
> + blkbits = ilog2(bdev_logical_block_size(bdev));

bdev->bd_inode->i_blkbits.

> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index cb05f71cf850..b896da27942a 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -3458,7 +3458,7 @@ static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
>
> if (align & blocksize_mask) {
> if (bdev)
> - blkbits = blksize_bits(bdev_logical_block_size(bdev));
> + blkbits = ilog2(bdev_logical_block_size(bdev));

bdev->bd_inode->i_blkbits.

> blocksize_mask = (1 << blkbits) - 1;
> if (align & blocksize_mask)
> return -EINVAL;
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index ec7b78e6feca..2a807657d544 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -203,7 +203,7 @@ static loff_t
> iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
> struct iomap_dio *dio, struct iomap *iomap)
> {
> - unsigned int blkbits = blksize_bits(bdev_logical_block_size(iomap->bdev));
> + unsigned int blkbits = ilog2(bdev_logical_block_size(iomap->bdev));

iomap->bdev->bd_inode->i_blkbits.