[PATCH 08/11] ext4: consolidate fsverity_info lookup

[Christoph Hellwig <hch@lst.de>]

Look up the fsverity_info once in ext4_mpage_readpages, and then use it
for the readahead, local verification of holes and pass it along to the
I/O completion workqueue in struct bio_post_read_ctx.

This amortizes the lookup better once it becomes less efficient.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
---
 fs/ext4/readpage.c | 46 ++++++++++++++++++++++------------------------
 1 file changed, 22 insertions(+), 24 deletions(-)

diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
index 823d67e98c70..09acca898c25 100644
--- a/fs/ext4/readpage.c
+++ b/fs/ext4/readpage.c
@@ -62,6 +62,7 @@ enum bio_post_read_step {
 
 struct bio_post_read_ctx {
 	struct bio *bio;
+	struct fsverity_info *vi;
 	struct work_struct work;
 	unsigned int cur_step;
 	unsigned int enabled_steps;
@@ -97,7 +98,7 @@ static void verity_work(struct work_struct *work)
 	struct bio_post_read_ctx *ctx =
 		container_of(work, struct bio_post_read_ctx, work);
 	struct bio *bio = ctx->bio;
-	struct inode *inode = bio_first_folio_all(bio)->mapping->host;
+	struct fsverity_info *vi = ctx->vi;
 
 	/*
 	 * fsverity_verify_bio() may call readahead() again, and although verity
@@ -110,7 +111,7 @@ static void verity_work(struct work_struct *work)
 	mempool_free(ctx, bio_post_read_ctx_pool);
 	bio->bi_private = NULL;
 
-	fsverity_verify_bio(*fsverity_info_addr(inode), bio);
+	fsverity_verify_bio(vi, bio);
 
 	__read_end_io(bio);
 }
@@ -174,22 +175,16 @@ static void mpage_end_io(struct bio *bio)
 	__read_end_io(bio);
 }
 
-static inline bool ext4_need_verity(const struct inode *inode, pgoff_t idx)
-{
-	return fsverity_active(inode) &&
-	       idx < DIV_ROUND_UP(inode->i_size, PAGE_SIZE);
-}
-
 static void ext4_set_bio_post_read_ctx(struct bio *bio,
 				       const struct inode *inode,
-				       pgoff_t first_idx)
+				       struct fsverity_info *vi)
 {
 	unsigned int post_read_steps = 0;
 
 	if (fscrypt_inode_uses_fs_layer_crypto(inode))
 		post_read_steps |= 1 << STEP_DECRYPT;
 
-	if (ext4_need_verity(inode, first_idx))
+	if (vi)
 		post_read_steps |= 1 << STEP_VERITY;
 
 	if (post_read_steps) {
@@ -198,6 +193,7 @@ static void ext4_set_bio_post_read_ctx(struct bio *bio,
 			mempool_alloc(bio_post_read_ctx_pool, GFP_NOFS);
 
 		ctx->bio = bio;
+		ctx->vi = vi;
 		ctx->enabled_steps = post_read_steps;
 		bio->bi_private = ctx;
 	}
@@ -211,7 +207,7 @@ static inline loff_t ext4_readpage_limit(struct inode *inode)
 	return i_size_read(inode);
 }
 
-static int ext4_mpage_readpages(struct inode *inode,
+static int ext4_mpage_readpages(struct inode *inode, struct fsverity_info *vi,
 		struct readahead_control *rac, struct folio *folio)
 {
 	struct bio *bio = NULL;
@@ -331,10 +327,7 @@ static int ext4_mpage_readpages(struct inode *inode,
 			folio_zero_segment(folio, first_hole << blkbits,
 					  folio_size(folio));
 			if (first_hole == 0) {
-				if (ext4_need_verity(inode, folio->index) &&
-				    !fsverity_verify_folio(
-						*fsverity_info_addr(inode),
-						folio))
+				if (vi && !fsverity_verify_folio(vi, folio))
 					goto set_error_page;
 				folio_end_read(folio, true);
 				continue;
@@ -362,7 +355,7 @@ static int ext4_mpage_readpages(struct inode *inode,
 					REQ_OP_READ, GFP_KERNEL);
 			fscrypt_set_bio_crypt_ctx(bio, inode, next_block,
 						  GFP_KERNEL);
-			ext4_set_bio_post_read_ctx(bio, inode, folio->index);
+			ext4_set_bio_post_read_ctx(bio, inode, vi);
 			bio->bi_iter.bi_sector = first_block << (blkbits - 9);
 			bio->bi_end_io = mpage_end_io;
 			if (rac)
@@ -401,6 +394,7 @@ static int ext4_mpage_readpages(struct inode *inode,
 int ext4_read_folio(struct file *file, struct folio *folio)
 {
 	struct inode *inode = folio->mapping->host;
+	struct fsverity_info *vi = NULL;
 	int ret;
 
 	trace_ext4_read_folio(inode, folio);
@@ -411,24 +405,28 @@ int ext4_read_folio(struct file *file, struct folio *folio)
 			return ret;
 	}
 
-	if (ext4_need_verity(inode, folio->index))
-		fsverity_readahead(*fsverity_info_addr(inode), folio->index,
-				   folio_nr_pages(folio));
-	return ext4_mpage_readpages(inode, NULL, folio);
+	if (folio->index < DIV_ROUND_UP(inode->i_size, PAGE_SIZE))
+		vi = fsverity_get_info(inode);
+	if (vi)
+		fsverity_readahead(vi, folio->index, folio_nr_pages(folio));
+	return ext4_mpage_readpages(inode, vi, NULL, folio);
 }
 
 void ext4_readahead(struct readahead_control *rac)
 {
 	struct inode *inode = rac->mapping->host;
+	struct fsverity_info *vi = NULL;
 
 	/* If the file has inline data, no need to do readahead. */
 	if (ext4_has_inline_data(inode))
 		return;
 
-	if (ext4_need_verity(inode, readahead_index(rac)))
-		fsverity_readahead(*fsverity_info_addr(inode),
-				   readahead_index(rac), readahead_count(rac));
-	ext4_mpage_readpages(inode, rac, NULL);
+	if (readahead_index(rac) < DIV_ROUND_UP(inode->i_size, PAGE_SIZE))
+		vi = fsverity_get_info(inode);
+	if (vi)
+		fsverity_readahead(vi, readahead_index(rac),
+				   readahead_count(rac));
+	ext4_mpage_readpages(inode, vi, rac, NULL);
 }
 
 
-- 
2.47.3