This is a note to let you know that I've just added the patch titled cifs: destage dirty pages before re-reading them for cache=none to the 5.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cifs-destage-dirty-pages-before-re-reading-them-for-cache-none.patch and it can be found in the queue-5.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From bb44c31cdcac107344dd2fcc3bd0504a53575c51 Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg <lsahlber@xxxxxxxxxx> Date: Tue, 20 Sep 2022 14:32:02 +1000 Subject: cifs: destage dirty pages before re-reading them for cache=none From: Ronnie Sahlberg <lsahlber@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx Reviewed-by: Paulo Alcantara (SUSE) <pc@xxxxxx> Reviewed-by: Enzo Matsumiya <ematsumiya@xxxxxxx> Signed-off-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/cifs/file.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -4024,6 +4024,15 @@ 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); Patches currently in stable-queue which might be from lsahlber@xxxxxxxxxx are queue-5.19/cifs-destage-dirty-pages-before-re-reading-them-for-cache-none.patch