[PATCH 2/7] minixfs: Convert minix_find_entry() to take a folio

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

Remove a few hidden calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/minix/dir.c   | 25 +++++++++++--------------
 fs/minix/minix.h | 14 +++++++-------
 fs/minix/namei.c | 25 ++++++++++++-------------
 3 files changed, 30 insertions(+), 34 deletions(-)

diff --git a/fs/minix/dir.c b/fs/minix/dir.c
index 41e6c0c2e243..3bbfac32d520 100644
--- a/fs/minix/dir.c
+++ b/fs/minix/dir.c
@@ -145,12 +145,13 @@ static inline int namecompare(int len, int maxlen,
 /*
  *	minix_find_entry()
  *
- * finds an entry in the specified directory with the wanted name. It
- * returns the cache buffer in which the entry was found, and the entry
- * itself (as a parameter - res_dir). It does NOT read the inode of the
+ * finds an entry in the specified directory with the wanted name.
+ * It does NOT read the inode of the
  * entry - you'll have to do that yourself if you want to.
+ * 
+ * On Success folio_release_kmap() should be called on *foliop.
  */
-minix_dirent *minix_find_entry(struct dentry *dentry, struct page **res_page)
+minix_dirent *minix_find_entry(struct dentry *dentry, struct folio **foliop)
 {
 	const char * name = dentry->d_name.name;
 	int namelen = dentry->d_name.len;
@@ -159,17 +160,15 @@ minix_dirent *minix_find_entry(struct dentry *dentry, struct page **res_page)
 	struct minix_sb_info * sbi = minix_sb(sb);
 	unsigned long n;
 	unsigned long npages = dir_pages(dir);
-	struct folio *folio = NULL;
 	char *p;
 
 	char *namx;
 	__u32 inumber;
-	*res_page = NULL;
 
 	for (n = 0; n < npages; n++) {
 		char *kaddr, *limit;
 
-		kaddr = dir_get_folio(dir, n, &folio);
+		kaddr = dir_get_folio(dir, n, foliop);
 		if (IS_ERR(kaddr))
 			continue;
 
@@ -189,12 +188,11 @@ minix_dirent *minix_find_entry(struct dentry *dentry, struct page **res_page)
 			if (namecompare(namelen, sbi->s_namelen, name, namx))
 				goto found;
 		}
-		folio_release_kmap(folio, kaddr);
+		folio_release_kmap(*foliop, kaddr);
 	}
 	return NULL;
 
 found:
-	*res_page = &folio->page;
 	return (minix_dirent *)p;
 }
 
@@ -445,20 +443,19 @@ struct minix_dir_entry * minix_dotdot (struct inode *dir, struct page **p)
 
 ino_t minix_inode_by_name(struct dentry *dentry)
 {
-	struct page *page;
-	struct minix_dir_entry *de = minix_find_entry(dentry, &page);
+	struct folio *folio;
+	struct minix_dir_entry *de = minix_find_entry(dentry, &folio);
 	ino_t res = 0;
 
 	if (de) {
-		struct address_space *mapping = page->mapping;
-		struct inode *inode = mapping->host;
+		struct inode *inode = folio->mapping->host;
 		struct minix_sb_info *sbi = minix_sb(inode->i_sb);
 
 		if (sbi->s_version == MINIX_V3)
 			res = ((minix3_dirent *) de)->inode;
 		else
 			res = de->inode;
-		unmap_and_put_page(page, de);
+		folio_release_kmap(folio, de);
 	}
 	return res;
 }
diff --git a/fs/minix/minix.h b/fs/minix/minix.h
index d493507c064f..a290dd483e69 100644
--- a/fs/minix/minix.h
+++ b/fs/minix/minix.h
@@ -64,15 +64,15 @@ extern int V2_minix_get_block(struct inode *, long, struct buffer_head *, int);
 extern unsigned V1_minix_blocks(loff_t, struct super_block *);
 extern unsigned V2_minix_blocks(loff_t, struct super_block *);
 
-extern struct minix_dir_entry *minix_find_entry(struct dentry*, struct page**);
-extern int minix_add_link(struct dentry*, struct inode*);
-extern int minix_delete_entry(struct minix_dir_entry*, struct page*);
-extern int minix_make_empty(struct inode*, struct inode*);
-extern int minix_empty_dir(struct inode*);
+struct minix_dir_entry *minix_find_entry(struct dentry *, struct folio **);
+int minix_add_link(struct dentry*, struct inode*);
+int minix_delete_entry(struct minix_dir_entry*, struct page*);
+int minix_make_empty(struct inode*, struct inode*);
+int minix_empty_dir(struct inode*);
 int minix_set_link(struct minix_dir_entry *de, struct page *page,
 		struct inode *inode);
-extern struct minix_dir_entry *minix_dotdot(struct inode*, struct page**);
-extern ino_t minix_inode_by_name(struct dentry*);
+struct minix_dir_entry *minix_dotdot(struct inode*, struct page**);
+ino_t minix_inode_by_name(struct dentry*);
 
 extern const struct inode_operations minix_file_inode_operations;
 extern const struct inode_operations minix_dir_inode_operations;
diff --git a/fs/minix/namei.c b/fs/minix/namei.c
index d6031acc34f0..117264877bd7 100644
--- a/fs/minix/namei.c
+++ b/fs/minix/namei.c
@@ -141,15 +141,15 @@ static int minix_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 static int minix_unlink(struct inode * dir, struct dentry *dentry)
 {
 	struct inode * inode = d_inode(dentry);
-	struct page * page;
+	struct folio *folio;
 	struct minix_dir_entry * de;
 	int err;
 
-	de = minix_find_entry(dentry, &page);
+	de = minix_find_entry(dentry, &folio);
 	if (!de)
 		return -ENOENT;
-	err = minix_delete_entry(de, page);
-	unmap_and_put_page(page, de);
+	err = minix_delete_entry(de, &folio->page);
+	folio_release_kmap(folio, de);
 
 	if (err)
 		return err;
@@ -182,14 +182,14 @@ static int minix_rename(struct mnt_idmap *idmap,
 	struct inode * new_inode = d_inode(new_dentry);
 	struct page * dir_page = NULL;
 	struct minix_dir_entry * dir_de = NULL;
-	struct page * old_page;
+	struct folio *old_folio;
 	struct minix_dir_entry * old_de;
 	int err = -ENOENT;
 
 	if (flags & ~RENAME_NOREPLACE)
 		return -EINVAL;
 
-	old_de = minix_find_entry(old_dentry, &old_page);
+	old_de = minix_find_entry(old_dentry, &old_folio);
 	if (!old_de)
 		goto out;
 
@@ -201,7 +201,7 @@ static int minix_rename(struct mnt_idmap *idmap,
 	}
 
 	if (new_inode) {
-		struct page * new_page;
+		struct folio *new_folio;
 		struct minix_dir_entry * new_de;
 
 		err = -ENOTEMPTY;
@@ -209,12 +209,11 @@ static int minix_rename(struct mnt_idmap *idmap,
 			goto out_dir;
 
 		err = -ENOENT;
-		new_de = minix_find_entry(new_dentry, &new_page);
+		new_de = minix_find_entry(new_dentry, &new_folio);
 		if (!new_de)
 			goto out_dir;
-		err = minix_set_link(new_de, new_page, old_inode);
-		kunmap(new_page);
-		put_page(new_page);
+		err = minix_set_link(new_de, &new_folio->page, old_inode);
+		folio_release_kmap(new_folio, new_de);
 		if (err)
 			goto out_dir;
 		inode_set_ctime_current(new_inode);
@@ -229,7 +228,7 @@ static int minix_rename(struct mnt_idmap *idmap,
 			inode_inc_link_count(new_dir);
 	}
 
-	err = minix_delete_entry(old_de, old_page);
+	err = minix_delete_entry(old_de, &old_folio->page);
 	if (err)
 		goto out_dir;
 
@@ -244,7 +243,7 @@ static int minix_rename(struct mnt_idmap *idmap,
 	if (dir_de)
 		unmap_and_put_page(dir_page, dir_de);
 out_old:
-	unmap_and_put_page(old_page, old_de);
+	folio_release_kmap(old_folio, old_de);
 out:
 	return err;
 }
-- 
2.43.0