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 5.10-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-5.10 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
@@ -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);
Patches currently in stable-queue which might be from lsahlber@xxxxxxxxxx are
queue-5.10/cifs-destage-dirty-pages-before-re-reading-them-for-cache-none.patch
