Function generic_file_direct_write() tries to invalidate pagecache after
O_DIRECT write. Unlike to similar code in dio_complete() this silently
ignores error returned from invalidate_inode_pages2_range().
According to comment this code here because not all filesystems call
dio_complete() to do proper invalidation after O_DIRECT write.
Noticeable example is a blkdev_direct_IO().
This patch calls dio_warn_stale_pagecache() if invalidation fails.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
---
mm/filemap.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index 189b8f318da2..dc3b78db079b 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3241,11 +3241,13 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
* do not end up with dio_complete() being called, so let's not break
* them by removing it completely.
*
+ * Noticeable example is a blkdev_direct_IO().
+ *
* Skip invalidation for async writes or if mapping has no pages.
*/
- if (written > 0 && mapping->nrpages)
- invalidate_inode_pages2_range(mapping,
- pos >> PAGE_SHIFT, end);
+ if (written > 0 && mapping->nrpages &&
+ invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT, end))
+ dio_warn_stale_pagecache(file);
if (written > 0) {
pos += written;
