[PATCH 4.14 169/246] f2fs: avoid fsync() failure caused by EAGAIN in writepage()

From: Greg Kroah-Hartman
Date: Wed Aug 01 2018 - 13:20:18 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>

[ Upstream commit 5b19d284f5195a925dd015a6397bfce184097378 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/f2fs/data.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1601,7 +1601,13 @@ out:

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;