[PATCH v5 16/18] mm/filemap: Don't relock the page after calling readpage

[Matthew Wilcox (Oracle)]

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.

Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstr...@gmail.com>
Reviewed-by: Christoph Hellwig <h...@lst.de>
---
 mm/filemap.c | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 1fba96dab4b8e..542d9c93732c2 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2227,23 +2227,16 @@ 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,
-- 
2.29.2