[PATCH] f2fs: avoid fsync() failure caused by EAGAIN in writepage()

[Jaegeuk Kim]

pageout() in MM traslates EAGAIN, so calls handle_write_error()
 -> mapping_set_error() -> set_bit(AS_EIO, ...).
 file_write_and_wait_range() will see EIO error, which is critical
 to return value of fsync() followed by atomic_write failure to user.

Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
---
 fs/f2fs/data.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 5477fc09c3cd..ac8720fa5868 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1904,7 +1904,13 @@ static int __write_data_page(struct page *page, bool 
*submitted,
 
 redirty_out:
        redirty_page_for_writepage(wbc, page);
-       if (!err)
+       /*
+        * pageout() in MM traslates EAGAIN, so calls handle_write_error()
+        * -> mapping_set_error() -> set_bit(AS_EIO, ...).
+        * file_write_and_wait_range() will see EIO error, which is critical
+        * to return value of fsync() followed by atomic_write failure to user.
+        */
+       if (!err || wbc->for_reclaim)
                return AOP_WRITEPAGE_ACTIVATE;
        unlock_page(page);
        return err;
-- 
2.17.0.484.g0c8726318c-goog