mm/filemap: don't relock the page after calling readpage

We don't need to get the page lock again; we just need to wait for the I/O
to finish, so use wait_on_page_locked_killable() like the other callers of
->readpage.

Link: https://lkml.kernel.org/r/20210122160140.223228-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/filemap.c b/mm/filemap.c
index 3311b2a..1358cb0 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2214,23 +2214,16 @@ static int filemap_read_page(struct file *file, struct address_space *mapping,
        error = mapping->a_ops->readpage(file, page);
        if (error)
                return error;
-       if (PageUptodate(page))
-               return 0;
 
-       error = lock_page_killable(page);
+       error = wait_on_page_locked_killable(page);
        if (error)
                return error;
-       if (!PageUptodate(page)) {
-               if (page->mapping == NULL) {
-                       /* page truncated */
-                       error = AOP_TRUNCATED_PAGE;
-               } else {
-                       shrink_readahead_size_eio(&file->f_ra);
-                       error = -EIO;
-               }
-       }
-       unlock_page(page);
-       return error;
+       if (PageUptodate(page))
+               return 0;
+       if (!page->mapping)     /* page truncated */
+               return AOP_TRUNCATED_PAGE;
+       shrink_readahead_size_eio(&file->f_ra);
+       return -EIO;
 }
 
 static bool filemap_range_uptodate(struct address_space *mapping,