[PATCH 02/13] 9p: Tell the VFS that readpage was synchronous

Matthew Wilcox (Oracle)
2020-09-17T15:12:40Z

The 9p readpage implementation was already synchronous, so use
AOP_UPDATED_PAGE to avoid cycling the page lock.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/9p/vfs_addr.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index cce9ace651a2..506ca0ba2ec7 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -65,7 +65,7 @@ static int v9fs_fid_readpage(void *data, struct page *page)
SetPageUptodate(page);

v9fs_readpage_to_fscache(inode, page);
- retval = 0;
+ return AOP_UPDATED_PAGE;

done:
unlock_page(page);
@@ -280,6 +280,10 @@ static int v9fs_write_begin(struct file *filp, struct address_space *mapping,
goto out;

retval = v9fs_fid_readpage(v9inode->writeback_fid, page);
+ if (retval == AOP_UPDATED_PAGE) {
+ retval = 0;
+ goto out;
+ }
put_page(page);
if (!retval)
goto start;