From: Ronnie Sahlberg lsahlber@redhat.com
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 --- 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);