From: Ronnie Sahlberg <lsahlber@redhat.com> stable inclusion from stable-v5.10.150 commit 64f23e5430d35e5ab81bfd7067eca078bbd20425 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0XA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit bb44c31cdcac107344dd2fcc3bd0504a53575c51 upstream. This is the opposite case of kernel bugzilla 216301. If we mmap a file using cache=none and then proceed to update the mmapped area these updates are not reflected in a later pread() of that part of the file. To fix this we must first destage any dirty pages in the range before we allow the pread() to proceed. Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com> --- fs/cifs/file.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index f6a1218366d1..0b840555a175 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -3936,6 +3936,15 @@ static ssize_t __cifs_readv( len = ctx->len; } + if (direct) { + rc = filemap_write_and_wait_range(file->f_inode->i_mapping, + offset, offset + len - 1); + if (rc) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return -EAGAIN; + } + } + /* grab a lock here due to read response handlers can access ctx */ mutex_lock(&ctx->aio_mutex); -- 2.25.1