Re: [PATCH 10/16] fs/buffer: Remove fs-layer decryption code

On Tue 23-06-26 22:03:28, Eric Biggers wrote:
> Now that fscrypt's file contents en/decryption is always implemented
> using blk-crypto when the filesystem is block-based, the fs-layer
> decryption code in fs/buffer.c is unused code.  Remove it.
> 
> Signed-off-by: Eric Biggers <[email protected]>

Fine by me. Feel free to add:

Reviewed-by: Jan Kara <[email protected]>

								Honza

> ---
>  fs/buffer.c | 45 ++++++++-------------------------------------
>  1 file changed, 8 insertions(+), 37 deletions(-)
> 
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 9af5f061a1f8..21dd9596a941 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -334,82 +334,53 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
>  
>  still_busy:
>  	spin_unlock_irqrestore(&first->b_uptodate_lock, flags);
>  }
>  
> -struct postprocess_bh_ctx {
> +struct verify_bh_ctx {
>  	struct work_struct work;
>  	struct buffer_head *bh;
>  	struct fsverity_info *vi;
>  };
>  
>  static void verify_bh(struct work_struct *work)
>  {
> -	struct postprocess_bh_ctx *ctx =
> -		container_of(work, struct postprocess_bh_ctx, work);
> +	struct verify_bh_ctx *ctx =
> +		container_of(work, struct verify_bh_ctx, work);
>  	struct buffer_head *bh = ctx->bh;
>  	bool valid;
>  
>  	valid = fsverity_verify_blocks(ctx->vi, bh->b_folio, bh->b_size,
>  				       bh_offset(bh));
>  	end_buffer_async_read(bh, valid);
>  	kfree(ctx);
>  }
>  
> -static void decrypt_bh(struct work_struct *work)
> -{
> -	struct postprocess_bh_ctx *ctx =
> -		container_of(work, struct postprocess_bh_ctx, work);
> -	struct buffer_head *bh = ctx->bh;
> -	int err;
> -
> -	err = fscrypt_decrypt_pagecache_blocks(bh->b_folio, bh->b_size,
> -					       bh_offset(bh));
> -	if (err == 0 && ctx->vi) {
> -		/*
> -		 * We use different work queues for decryption and for verity
> -		 * because verity may require reading metadata pages that need
> -		 * decryption, and we shouldn't recurse to the same workqueue.
> -		 */
> -		INIT_WORK(&ctx->work, verify_bh);
> -		fsverity_enqueue_verify_work(&ctx->work);
> -		return;
> -	}
> -	end_buffer_async_read(bh, err == 0);
> -	kfree(ctx);
> -}
> -
>  /*
>   * I/O completion handler for block_read_full_folio() - folios
>   * which come unlocked at the end of I/O.
>   */
>  static void bh_end_async_read(struct bio *bio)
>  {
>  	struct buffer_head *bh;
>  	bool uptodate = bio_endio_bh(bio, &bh);
>  	struct inode *inode = bh->b_folio->mapping->host;
> -	bool decrypt = fscrypt_inode_uses_fs_layer_crypto(inode);
>  	struct fsverity_info *vi = NULL;
>  
>  	/* needed by ext4 */
>  	if (bh->b_folio->index < DIV_ROUND_UP(inode->i_size, PAGE_SIZE))
>  		vi = fsverity_get_info(inode);
>  
> -	/* Decrypt (with fscrypt) and/or verify (with fsverity) if needed. */
> -	if (uptodate && (decrypt || vi)) {
> -		struct postprocess_bh_ctx *ctx = kmalloc_obj(*ctx, GFP_ATOMIC);
> +	/* Verify (with fsverity) if needed. */
> +	if (vi && uptodate) {
> +		struct verify_bh_ctx *ctx = kmalloc_obj(*ctx, GFP_ATOMIC);
>  
>  		if (ctx) {
>  			ctx->bh = bh;
>  			ctx->vi = vi;
> -			if (decrypt) {
> -				INIT_WORK(&ctx->work, decrypt_bh);
> -				fscrypt_enqueue_decrypt_work(&ctx->work);
> -			} else {
> -				INIT_WORK(&ctx->work, verify_bh);
> -				fsverity_enqueue_verify_work(&ctx->work);
> -			}
> +			INIT_WORK(&ctx->work, verify_bh);
> +			fsverity_enqueue_verify_work(&ctx->work);
>  			return;
>  		}
>  		uptodate = false;
>  	}
>  	end_buffer_async_read(bh, uptodate);
> -- 
> 2.54.0
> 
-- 
Jan Kara <[email protected]>
SUSE Labs, CR