From 7f9eda5908a8f893dc0ccd1d56001cccf4562325 Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Thu, 31 Oct 2019 14:18:57 -0700 Subject: [PATCH] CIFS: Fix SMB2 oplock break processing commit fa9c2362497fbd64788063288dc4e74daf977ebb upstream. 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 Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- 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 9994d15a32fc..7b7b47e26dbd 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -617,10 +617,10 @@ 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, @@ -632,6 +632,8 @@ 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) && @@ -664,9 +666,6 @@ 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); -- 2.20.1