Re: [f2fs-dev] [PATCH] f2fs: make get_lock_data_page to handle encrypted inode

[Chao Yu]

On 2017/9/7 12:46, Jaegeuk Kim wrote:
> This patch refactors get_lock_data_page() to handle encryption case directly.
> In order to do that, it introduces common f2fs_submit_page_read().
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>

Good cleanup job.

Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>

Thanks,

> ---
>  fs/f2fs/data.c | 109 +++++++++++++++++++++++++++------------------------------
>  1 file changed, 51 insertions(+), 58 deletions(-)
> 
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index ee6801fdbdec..95f30f0000b6 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -456,6 +456,53 @@ int f2fs_submit_page_write(struct f2fs_io_info *fio)
>  	return err;
>  }
>  
> +static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
> +							 unsigned nr_pages)
> +{
> +	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> +	struct fscrypt_ctx *ctx = NULL;
> +	struct bio *bio;
> +
> +	if (f2fs_encrypted_file(inode)) {
> +		ctx = fscrypt_get_ctx(inode, GFP_NOFS);
> +		if (IS_ERR(ctx))
> +			return ERR_CAST(ctx);
> +
> +		/* wait the page to be moved by cleaning */
> +		f2fs_wait_on_block_writeback(sbi, blkaddr);
> +	}
> +
> +	bio = bio_alloc(GFP_KERNEL, min_t(int, nr_pages, BIO_MAX_PAGES));
> +	if (!bio) {
> +		if (ctx)
> +			fscrypt_release_ctx(ctx);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +	f2fs_target_device(sbi, blkaddr, bio);
> +	bio->bi_end_io = f2fs_read_end_io;
> +	bio->bi_private = ctx;
> +	bio_set_op_attrs(bio, REQ_OP_READ, 0);
> +
> +	return bio;
> +}
> +
> +/* This can handle encryption stuffs */
> +static int f2fs_submit_page_read(struct inode *inode, struct page *page,
> +							block_t blkaddr)
> +{
> +	struct bio *bio = f2fs_grab_read_bio(inode, blkaddr, 1);
> +
> +	if (IS_ERR(bio))
> +		return PTR_ERR(bio);
> +
> +	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
> +		bio_put(bio);
> +		return -EFAULT;
> +	}
> +	__submit_bio(F2FS_I_SB(inode), bio, DATA);
> +	return 0;
> +}
> +
>  static void __set_data_blkaddr(struct dnode_of_data *dn)
>  {
>  	struct f2fs_node *rn = F2FS_NODE(dn->node_page);
> @@ -573,16 +620,6 @@ struct page *get_read_data_page(struct inode *inode, pgoff_t index,
>  	struct page *page;
>  	struct extent_info ei = {0,0,0};
>  	int err;
> -	struct f2fs_io_info fio = {
> -		.sbi = F2FS_I_SB(inode),
> -		.type = DATA,
> -		.op = REQ_OP_READ,
> -		.op_flags = op_flags,
> -		.encrypted_page = NULL,
> -	};
> -
> -	if (f2fs_encrypted_file(inode))
> -		return read_mapping_page(mapping, index, NULL);
>  
>  	page = f2fs_grab_cache_page(mapping, index, for_write);
>  	if (!page)
> @@ -623,9 +660,7 @@ struct page *get_read_data_page(struct inode *inode, pgoff_t index,
>  		return page;
>  	}
>  
> -	fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
> -	fio.page = page;
> -	err = f2fs_submit_page_bio(&fio);
> +	err = f2fs_submit_page_read(inode, page, dn.data_blkaddr);
>  	if (err)
>  		goto put_err;
>  	return page;
> @@ -1150,35 +1185,6 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
>  	return ret;
>  }
>  
> -static struct bio *f2fs_grab_bio(struct inode *inode, block_t blkaddr,
> -				 unsigned nr_pages)
> -{
> -	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> -	struct fscrypt_ctx *ctx = NULL;
> -	struct bio *bio;
> -
> -	if (f2fs_encrypted_file(inode)) {
> -		ctx = fscrypt_get_ctx(inode, GFP_NOFS);
> -		if (IS_ERR(ctx))
> -			return ERR_CAST(ctx);
> -
> -		/* wait the page to be moved by cleaning */
> -		f2fs_wait_on_block_writeback(sbi, blkaddr);
> -	}
> -
> -	bio = bio_alloc(GFP_KERNEL, min_t(int, nr_pages, BIO_MAX_PAGES));
> -	if (!bio) {
> -		if (ctx)
> -			fscrypt_release_ctx(ctx);
> -		return ERR_PTR(-ENOMEM);
> -	}
> -	f2fs_target_device(sbi, blkaddr, bio);
> -	bio->bi_end_io = f2fs_read_end_io;
> -	bio->bi_private = ctx;
> -
> -	return bio;
> -}
> -
>  /*
>   * This function was originally taken from fs/mpage.c, and customized for f2fs.
>   * Major change was from block_size == page_size in f2fs by default.
> @@ -1275,12 +1281,11 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
>  			bio = NULL;
>  		}
>  		if (bio == NULL) {
> -			bio = f2fs_grab_bio(inode, block_nr, nr_pages);
> +			bio = f2fs_grab_read_bio(inode, block_nr, nr_pages);
>  			if (IS_ERR(bio)) {
>  				bio = NULL;
>  				goto set_error_page;
>  			}
> -			bio_set_op_attrs(bio, REQ_OP_READ, 0);
>  		}
>  
>  		if (bio_add_page(bio, page, blocksize, 0) < blocksize)
> @@ -1989,21 +1994,9 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
>  		zero_user_segment(page, 0, PAGE_SIZE);
>  		SetPageUptodate(page);
>  	} else {
> -		struct bio *bio;
> -
> -		bio = f2fs_grab_bio(inode, blkaddr, 1);
> -		if (IS_ERR(bio)) {
> -			err = PTR_ERR(bio);
> -			goto fail;
> -		}
> -		bio->bi_opf = REQ_OP_READ;
> -		if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
> -			bio_put(bio);
> -			err = -EFAULT;
> +		err = f2fs_submit_page_read(inode, page, blkaddr);
> +		if (err)
>  			goto fail;
> -		}
> -
> -		__submit_bio(sbi, bio, DATA);
>  
>  		lock_page(page);
>  		if (unlikely(page->mapping != mapping)) {
>