From: Joel Stanley Date: Tue, 30 Mar 2021 13:45:37 +0000 (+1030) Subject: jffs2: Hook up splice_write callback X-Git-Tag: v5.11.20~73 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=39597530546a99c855c0fd4c1d6be30b20d839eb;p=thirdparty%2Fkernel%2Fstable.git jffs2: Hook up splice_write callback commit 42984af09afc414d540fcc8247f42894b0378a91 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c index f8fb89b10227c..4fc8cd698d1a4 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 */