fs/ext2: Use ext2_put_page

There are 3 places in namei.c where the equivalent of ext2_put_page() is
open coded on a page which was returned from the ext2_get_page() call
[through the use of ext2_find_entry() and ext2_dotdot()].

Move ext2_put_page() to ext2.h and use it in namei.c

Also add a comment regarding the proper way to release the page returned
from ext2_find_entry() and ext2_dotdot().

Link: https://lore.kernel.org/r/20201112174244.701325-1-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 8 insertions, 6 deletions

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 70355ab6740e..14aa45316ad2 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -66,12 +66,6 @@ static inline unsigned ext2_chunk_size(struct inode *inode)
 	return inode->i_sb->s_blocksize;
 }
 
-static inline void ext2_put_page(struct page *page)
-{
-	kunmap(page);
-	put_page(page);
-}
-
 /*
  * Return the offset into page `page_nr' of the last valid
  * byte in that page, plus one.
@@ -336,6 +330,8 @@ ext2_readdir(struct file *file, struct dir_context *ctx)
  * returns the page in which the entry was found (as a parameter - res_page),
  * and the entry itself. Page is returned mapped and unlocked.
  * Entry is guaranteed to be valid.
+ *
+ * On Success ext2_put_page() should be called on *res_page.
  */
 struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
 			const struct qstr *child, struct page **res_page)
@@ -401,6 +397,12 @@ found:
 	return de;
 }
 
+/**
+ * Return the '..' directory entry and the page in which the entry was found
+ * (as a parameter - p).
+ *
+ * On Success ext2_put_page() should be called on *p.
+ */
 struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
 {
 	struct page *page = ext2_get_page(dir, 0, 0);