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

From: Jaegeuk Kim
Date: Fri May 04 2018 - 13:52:20 EST


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 <jaegeuk@xxxxxxxxxx>
---
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