[PATCH 5/9] ext4/jbd2: convert jbd2_journal_blocks_per_page() to support large folio

[Zhang Yi <yi.zhang@xxxxxxxxxxxxxxx>]

From: Zhang Yi <yi.zhang@xxxxxxxxxx>

jbd2_journal_blocks_per_page() returns the number of blocks in a single
page. Rename it to jbd2_journal_blocks_per_folio() and make it returns
the number of blocks in the largest folio, preparing for the calculation
of journal credits blocks when allocating blocks within a large folio in
the writeback path.

Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
 fs/ext4/ext4_jbd2.h  | 4 ++--
 fs/ext4/inode.c      | 6 +++---
 fs/jbd2/journal.c    | 7 ++++---
 include/linux/jbd2.h | 2 +-
 4 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index 0c77697d5e90..59df14547d26 100644
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -403,10 +403,10 @@ static inline int ext4_journal_ensure_credits(handle_t *handle, int credits,
 				revoke_creds, 0);
 }
 
-static inline int ext4_journal_blocks_per_page(struct inode *inode)
+static inline int ext4_journal_blocks_per_folio(struct inode *inode)
 {
 	if (EXT4_JOURNAL(inode) != NULL)
-		return jbd2_journal_blocks_per_page(inode);
+		return jbd2_journal_blocks_per_folio(inode);
 	return 0;
 }
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 38d33569c26e..e7b485b0f81b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2346,7 +2346,7 @@ static int mpage_map_and_submit_extent(handle_t *handle,
  */
 static int ext4_da_writepages_trans_blocks(struct inode *inode)
 {
-	int bpp = ext4_journal_blocks_per_page(inode);
+	int bpp = ext4_journal_blocks_per_folio(inode);
 
 	return ext4_meta_trans_blocks(inode,
 				MAX_WRITEPAGES_EXTENT_LEN + bpp - 1, bpp);
@@ -2424,7 +2424,7 @@ static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
 	ext4_lblk_t lblk;
 	struct buffer_head *head;
 	handle_t *handle = NULL;
-	int bpp = ext4_journal_blocks_per_page(mpd->inode);
+	int bpp = ext4_journal_blocks_per_folio(mpd->inode);
 
 	if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages)
 		tag = PAGECACHE_TAG_TOWRITE;
@@ -5715,7 +5715,7 @@ static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
  */
 int ext4_writepage_trans_blocks(struct inode *inode)
 {
-	int bpp = ext4_journal_blocks_per_page(inode);
+	int bpp = ext4_journal_blocks_per_folio(inode);
 	int ret;
 
 	ret = ext4_meta_trans_blocks(inode, bpp, bpp);
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 97f487c3d8fc..a0b8662bc5d7 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -83,7 +83,7 @@ EXPORT_SYMBOL(jbd2_log_wait_commit);
 EXPORT_SYMBOL(jbd2_journal_start_commit);
 EXPORT_SYMBOL(jbd2_journal_force_commit_nested);
 EXPORT_SYMBOL(jbd2_journal_wipe);
-EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
+EXPORT_SYMBOL(jbd2_journal_blocks_per_folio);
 EXPORT_SYMBOL(jbd2_journal_invalidate_folio);
 EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
 EXPORT_SYMBOL(jbd2_journal_force_commit);
@@ -2680,9 +2680,10 @@ void jbd2_journal_ack_err(journal_t *journal)
 	write_unlock(&journal->j_state_lock);
 }
 
-int jbd2_journal_blocks_per_page(struct inode *inode)
+int jbd2_journal_blocks_per_folio(struct inode *inode)
 {
-	return 1 << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
+	return 1 << (PAGE_SHIFT + mapping_max_folio_order(inode->i_mapping) -
+		     inode->i_sb->s_blocksize_bits);
 }
 
 /*
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 8aef9bb6ad57..591f93ef7851 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1740,7 +1740,7 @@ static inline int tid_geq(tid_t x, tid_t y)
 	return (difference >= 0);
 }
 
-extern int jbd2_journal_blocks_per_page(struct inode *inode);
+extern int jbd2_journal_blocks_per_folio(struct inode *inode);
 extern size_t journal_tag_bytes(journal_t *journal);
 
 static inline bool jbd2_journal_has_csum_v2or3_feature(journal_t *j)
-- 
2.46.1