Commit f6ae956d authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Eric Biggers
Browse files

fs: consolidate fsverity_info lookup in buffer.c 



Look up the fsverity_info once in end_buffer_async_read_io, and then
pass it along to the I/O completion workqueue in
struct postprocess_bh_ctx.

This amortizes the lookup better once it becomes less efficient.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatar"Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20260202060754.270269-8-hch@lst.de


Signed-off-by: default avatarEric Biggers <ebiggers@kernel.org>
parent 47bc2ac9

fs/buffer.c

+11 −16
Original line number Diff line number Diff line
@@ -302,6 +302,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate) 
struct postprocess_bh_ctx {

	struct work_struct work;

	struct buffer_head *bh;

	struct fsverity_info *vi;

};



static void verify_bh(struct work_struct *work)
@@ -309,25 +310,14 @@ static void verify_bh(struct work_struct *work) 
	struct postprocess_bh_ctx *ctx =

		container_of(work, struct postprocess_bh_ctx, work);

	struct buffer_head *bh = ctx->bh;

	struct inode *inode = bh->b_folio->mapping->host;

	bool valid;



	valid = fsverity_verify_blocks(*fsverity_info_addr(inode), bh->b_folio,

				       bh->b_size, bh_offset(bh));

	valid = fsverity_verify_blocks(ctx->vi, bh->b_folio, bh->b_size,

				       bh_offset(bh));

	end_buffer_async_read(bh, valid);

	kfree(ctx);

}



static bool need_fsverity(struct buffer_head *bh)

{

	struct folio *folio = bh->b_folio;

	struct inode *inode = folio->mapping->host;



	return fsverity_active(inode) &&

		/* needed by ext4 */

		folio->index < DIV_ROUND_UP(inode->i_size, PAGE_SIZE);

}



static void decrypt_bh(struct work_struct *work)

{

	struct postprocess_bh_ctx *ctx =
@@ -337,7 +327,7 @@ static void decrypt_bh(struct work_struct *work) 


	err = fscrypt_decrypt_pagecache_blocks(bh->b_folio, bh->b_size,

					       bh_offset(bh));

	if (err == 0 && need_fsverity(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
@@ -359,15 +349,20 @@ static void end_buffer_async_read_io(struct buffer_head *bh, int uptodate) 
{

	struct inode *inode = bh->b_folio->mapping->host;

	bool decrypt = fscrypt_inode_uses_fs_layer_crypto(inode);

	bool verify = need_fsverity(bh);

	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 || verify)) {

	if (uptodate && (decrypt || vi)) {

		struct postprocess_bh_ctx *ctx =

			kmalloc(sizeof(*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);