From 9266a14033a81b3096feccd10542c20b3f47fe8e Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Sat, 30 Nov 2019 17:49:47 -0800 Subject: [PATCH] mm/filemap.c: warn if stale pagecache is left after direct write 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. Link: http://lkml.kernel.org/r/157270038294.4812.2238891109785106069.stgit@buzz Signed-off-by: Konstantin Khlebnikov Reviewed-by: Andrew Morton Reviewed-by: Jan Kara Cc: Jens Axboe Cc: Alexander Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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;