From 42984af09afc414d540fcc8247f42894b0378a91 Mon Sep 17 00:00:00 2001 From: Joel Stanley Date: Wed, 31 Mar 2021 00:15:37 +1030 Subject: jffs2: Hook up splice_write callback overlayfs using jffs2 as the upper filesystem would fail in some cases since moving to v5.10. The test case used was to run 'touch' on a file that exists in the lower fs, causing the modification time to be updated. It returns EINVAL when the bug is triggered. A bisection showed this was introduced in v5.9-rc1, with commit 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops"). Reverting that commit restores the expected behaviour. Some digging showed that this was due to jffs2 lacking an implementation of splice_write. (For unknown reasons the warn_unsupported that should trigger was not displaying any output). Adding this patch resolved the issue and the test now passes. Cc: stable@vger.kernel.org Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops") Signed-off-by: Joel Stanley Reviewed-by: Christoph Hellwig Tested-by: Lei YU Signed-off-by: Richard Weinberger --- fs/jffs2/file.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c index f8fb89b10227..4fc8cd698d1a 100644 --- a/fs/jffs2/file.c +++ b/fs/jffs2/file.c @@ -57,6 +57,7 @@ const struct file_operations jffs2_file_operations = .mmap = generic_file_readonly_mmap, .fsync = jffs2_fsync, .splice_read = generic_file_splice_read, + .splice_write = iter_file_splice_write, }; /* jffs2_file_inode_operations */ -- cgit v1.2.3