tentatively merged into cifs-2.6.git for-next pending review and
buildbot regression test runs
On Thu, Oct 31, 2019 at 5:50 PM Pavel Shilovsky <piastryyy@xxxxxxxxx> wrote:
>
> Even when mounting modern protocol version the server may be
> configured without supporting SMB2.1 leases and the client
> uses SMB2 oplock to optimize IO performance through local caching.
>
> However there is a problem in oplock break handling that leads
> to missing a break notification on the client who has a file
> opened. It latter causes big latencies to other clients that
> are trying to open the same file.
>
> The problem reproduces when there are multiple shares from the
> same server mounted on the client. The processing code tries to
> match persistent and volatile file ids from the break notification
> with an open file but it skips all share besides the first one.
> Fix this by looking up in all shares belonging to the server that
> issued the oplock break.
>
> Cc: Stable <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
> ---
> fs/cifs/smb2misc.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
> index 8db6201b18ba..527c9efd3de0 100644
> --- a/fs/cifs/smb2misc.c
> +++ b/fs/cifs/smb2misc.c
> @@ -664,10 +664,10 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
> spin_lock(&cifs_tcp_ses_lock);
> list_for_each(tmp, &server->smb_ses_list) {
> ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
> +
> list_for_each(tmp1, &ses->tcon_list) {
> tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
>
> - cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
> spin_lock(&tcon->open_file_lock);
> list_for_each(tmp2, &tcon->openFileList) {
> cfile = list_entry(tmp2, struct cifsFileInfo,
> @@ -679,6 +679,8 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
> continue;
>
> cifs_dbg(FYI, "file id match, oplock break\n");
> + cifs_stats_inc(
> + &tcon->stats.cifs_stats.num_oplock_brks);
> cinode = CIFS_I(d_inode(cfile->dentry));
> spin_lock(&cfile->file_info_lock);
> if (!CIFS_CACHE_WRITE(cinode) &&
> @@ -702,9 +704,6 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
> return true;
> }
> spin_unlock(&tcon->open_file_lock);
> - spin_unlock(&cifs_tcp_ses_lock);
> - cifs_dbg(FYI, "No matching file for oplock break\n");
> - return true;
> }
> }
> spin_unlock(&cifs_tcp_ses_lock);
> --
> 2.17.1
>
--
Thanks,
Steve
