[PATCH 10/11] btrfs: consolidate fsverity_info lookup

[Christoph Hellwig <hch@lst.de>]

Look up the fsverity_info once in btrfs_do_readpage, and then use it
for all operations performed there, and do the same in end_folio_read
for all folios processed there.  The latter is also changed to derive
the inode from the btrfs_bio - while bbio->inode is optional, it is
always set for buffered reads.

This amortizes the lookup better once it becomes less efficient.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/extent_io.c | 54 +++++++++++++++++++++++++++-----------------
 1 file changed, 33 insertions(+), 21 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 21430b7d8f27..24988520521c 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -476,26 +476,25 @@ void extent_clear_unlock_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
 				end, page_ops);
 }
 
-static bool btrfs_verify_folio(struct folio *folio, u64 start, u32 len)
+static bool btrfs_verify_folio(struct fsverity_info *vi, struct folio *folio,
+			       u64 start, u32 len)
 {
 	struct btrfs_fs_info *fs_info = folio_to_fs_info(folio);
 
-	if (!fsverity_active(folio->mapping->host) ||
-	    btrfs_folio_test_uptodate(fs_info, folio, start, len) ||
-	    start >= i_size_read(folio->mapping->host))
+	if (!vi || btrfs_folio_test_uptodate(fs_info, folio, start, len))
 		return true;
-	return fsverity_verify_folio(*fsverity_info_addr(folio->mapping->host),
-			folio);
+	return fsverity_verify_folio(vi, folio);
 }
 
-static void end_folio_read(struct folio *folio, bool uptodate, u64 start, u32 len)
+static void end_folio_read(struct fsverity_info *vi, struct folio *folio,
+			   bool uptodate, u64 start, u32 len)
 {
 	struct btrfs_fs_info *fs_info = folio_to_fs_info(folio);
 
 	ASSERT(folio_pos(folio) <= start &&
 	       start + len <= folio_next_pos(folio));
 
-	if (uptodate && btrfs_verify_folio(folio, start, len))
+	if (uptodate && btrfs_verify_folio(vi, folio, start, len))
 		btrfs_folio_set_uptodate(fs_info, folio, start, len);
 	else
 		btrfs_folio_clear_uptodate(fs_info, folio, start, len);
@@ -575,14 +574,19 @@ static void begin_folio_read(struct btrfs_fs_info *fs_info, struct folio *folio)
 static void end_bbio_data_read(struct btrfs_bio *bbio)
 {
 	struct btrfs_fs_info *fs_info = bbio->inode->root->fs_info;
+	struct inode *inode = &bbio->inode->vfs_inode;
 	struct bio *bio = &bbio->bio;
+	struct fsverity_info *vi = NULL;
 	struct folio_iter fi;
 
 	ASSERT(!bio_flagged(bio, BIO_CLONED));
+
+	if (bbio->file_offset < i_size_read(inode))
+		vi = fsverity_get_info(inode);
+
 	bio_for_each_folio_all(fi, &bbio->bio) {
 		bool uptodate = !bio->bi_status;
 		struct folio *folio = fi.folio;
-		struct inode *inode = folio->mapping->host;
 		u64 start = folio_pos(folio) + fi.offset;
 
 		btrfs_debug(fs_info,
@@ -617,7 +621,7 @@ static void end_bbio_data_read(struct btrfs_bio *bbio)
 		}
 
 		/* Update page status and unlock. */
-		end_folio_read(folio, uptodate, start, fi.length);
+		end_folio_read(vi, folio, uptodate, start, fi.length);
 	}
 	bio_put(bio);
 }
@@ -992,7 +996,8 @@ static void btrfs_readahead_expand(struct readahead_control *ractl,
  * return 0 on success, otherwise return error
  */
 static int btrfs_do_readpage(struct folio *folio, struct extent_map **em_cached,
-			     struct btrfs_bio_ctrl *bio_ctrl)
+			     struct btrfs_bio_ctrl *bio_ctrl,
+			     struct fsverity_info *vi)
 {
 	struct inode *inode = folio->mapping->host;
 	struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
@@ -1030,16 +1035,16 @@ static int btrfs_do_readpage(struct folio *folio, struct extent_map **em_cached,
 		ASSERT(IS_ALIGNED(cur, fs_info->sectorsize));
 		if (cur >= last_byte) {
 			folio_zero_range(folio, pg_offset, end - cur + 1);
-			end_folio_read(folio, true, cur, end - cur + 1);
+			end_folio_read(vi, folio, true, cur, end - cur + 1);
 			break;
 		}
 		if (btrfs_folio_test_uptodate(fs_info, folio, cur, blocksize)) {
-			end_folio_read(folio, true, cur, blocksize);
+			end_folio_read(vi, folio, true, cur, blocksize);
 			continue;
 		}
 		em = get_extent_map(BTRFS_I(inode), folio, cur, end - cur + 1, em_cached);
 		if (IS_ERR(em)) {
-			end_folio_read(folio, false, cur, end + 1 - cur);
+			end_folio_read(vi, folio, false, cur, end + 1 - cur);
 			return PTR_ERR(em);
 		}
 		extent_offset = cur - em->start;
@@ -1116,12 +1121,12 @@ static int btrfs_do_readpage(struct folio *folio, struct extent_map **em_cached,
 		/* we've found a hole, just zero and go on */
 		if (block_start == EXTENT_MAP_HOLE) {
 			folio_zero_range(folio, pg_offset, blocksize);
-			end_folio_read(folio, true, cur, blocksize);
+			end_folio_read(vi, folio, true, cur, blocksize);
 			continue;
 		}
 		/* the get_extent function already copied into the folio */
 		if (block_start == EXTENT_MAP_INLINE) {
-			end_folio_read(folio, true, cur, blocksize);
+			end_folio_read(vi, folio, true, cur, blocksize);
 			continue;
 		}
 
@@ -1318,7 +1323,8 @@ static void lock_extents_for_read(struct btrfs_inode *inode, u64 start, u64 end,
 
 int btrfs_read_folio(struct file *file, struct folio *folio)
 {
-	struct btrfs_inode *inode = folio_to_inode(folio);
+	struct inode *vfs_inode = folio->mapping->host;
+	struct btrfs_inode *inode = BTRFS_I(vfs_inode);
 	const u64 start = folio_pos(folio);
 	const u64 end = start + folio_size(folio) - 1;
 	struct extent_state *cached_state = NULL;
@@ -1327,10 +1333,13 @@ int btrfs_read_folio(struct file *file, struct folio *folio)
 		.last_em_start = U64_MAX,
 	};
 	struct extent_map *em_cached = NULL;
+	struct fsverity_info *vi = NULL;
 	int ret;
 
 	lock_extents_for_read(inode, start, end, &cached_state);
-	ret = btrfs_do_readpage(folio, &em_cached, &bio_ctrl);
+	if (folio_pos(folio) < i_size_read(vfs_inode))
+		vi = fsverity_get_info(vfs_inode);
+	ret = btrfs_do_readpage(folio, &em_cached, &bio_ctrl, vi);
 	btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state);
 
 	btrfs_free_extent_map(em_cached);
@@ -2697,16 +2706,19 @@ void btrfs_readahead(struct readahead_control *rac)
 		.last_em_start = U64_MAX,
 	};
 	struct folio *folio;
-	struct btrfs_inode *inode = BTRFS_I(rac->mapping->host);
+	struct inode *vfs_inode = rac->mapping->host;
+	struct btrfs_inode *inode = BTRFS_I(vfs_inode);
 	const u64 start = readahead_pos(rac);
 	const u64 end = start + readahead_length(rac) - 1;
 	struct extent_state *cached_state = NULL;
 	struct extent_map *em_cached = NULL;
+	struct fsverity_info *vi = NULL;
 
 	lock_extents_for_read(inode, start, end, &cached_state);
-
+	if (start < i_size_read(vfs_inode))
+		vi = fsverity_get_info(vfs_inode);
 	while ((folio = readahead_folio(rac)) != NULL)
-		btrfs_do_readpage(folio, &em_cached, &bio_ctrl);
+		btrfs_do_readpage(folio, &em_cached, &bio_ctrl, vi);
 
 	btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state);
 
-- 
2.47.3