minix: fix error handling in minix_set_link

If minix_prepare_chunk fails, updating c/mtime and marking the
dir inode dirty is wrong, as the inode hasn't been modified.  Also
propagate the error to the caller.

Note that this moves the dir_put_page call later, but that matches
other uses of this helper in the directory code.

Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Al Viro <[email protected]>

Author: Christoph Hellwig

fs/minix/dir.c

@@ -410,8 +410,8 @@ int minix_empty_dir(struct inode * inode)
 }
 
 /* Releases the page */
-void minix_set_link(struct minix_dir_entry *de, struct page *page,
-	struct inode *inode)
+int minix_set_link(struct minix_dir_entry *de, struct page *page,
+		struct inode *inode)
 {
 	struct inode *dir = page->mapping->host;
 	struct minix_sb_info *sbi = minix_sb(dir->i_sb);
@@ -420,19 +420,21 @@ void minix_set_link(struct minix_dir_entry *de, struct page *page,
 	int err;
 
 	lock_page(page);
-
 	err = minix_prepare_chunk(page, pos, sbi->s_dirsize);
-	if (err == 0) {
-		if (sbi->s_version == MINIX_V3)
-			((minix3_dirent *) de)->inode = inode->i_ino;
-		else
-			de->inode = inode->i_ino;
-		err = dir_commit_chunk(page, pos, sbi->s_dirsize);
-	} else {
+	if (err) {
 		unlock_page(page);
+		return err;
 	}
+	if (sbi->s_version == MINIX_V3)
+		((minix3_dirent *)de)->inode = inode->i_ino;
+	else
+		de->inode = inode->i_ino;
+	err = dir_commit_chunk(page, pos, sbi->s_dirsize);
+	if (err)
+		return err;
 	dir->i_mtime = dir->i_ctime = current_time(dir);
 	mark_inode_dirty(dir);
+	return 0;
 }
 
 struct minix_dir_entry * minix_dotdot (struct inode *dir, struct page **p)

fs/minix/minix.h

@@ -69,7 +69,8 @@ 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*);
-extern void minix_set_link(struct minix_dir_entry*, struct page*, 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*);
 

fs/minix/namei.c

@@ -213,10 +213,11 @@ static int minix_rename(struct user_namespace *mnt_userns,
 		new_de = minix_find_entry(new_dentry, &new_page);
 		if (!new_de)
 			goto out_dir;
-		err = 0;
-		minix_set_link(new_de, new_page, old_inode);
+		err = minix_set_link(new_de, new_page, old_inode);
 		kunmap(new_page);
 		put_page(new_page);
+		if (err)
+			goto out_dir;
 		new_inode->i_ctime = current_time(new_inode);
 		if (dir_de)
 			drop_nlink(new_inode);
@@ -233,8 +234,9 @@ static int minix_rename(struct user_namespace *mnt_userns,
 	mark_inode_dirty(old_inode);
 
 	if (dir_de) {
-		minix_set_link(dir_de, dir_page, new_dir);
-		inode_dec_link_count(old_dir);
+		err = minix_set_link(dir_de, dir_page, new_dir);
+		if (!err)
+			inode_dec_link_count(old_dir);
 	}
 out_dir:
 	if (dir_de) {