From: Pavel Shilovsky <piastryyy@gmail.com>
To: linux-cifs@vger.kernel.org
Cc: stable@vger.kernel.org
Subject: [PATCH] CIFS: Fix SMB2 oplock break processing
Date: Thu, 31 Oct 2019 14:18:57 -0700 [thread overview]
Message-ID: <20191031211857.18989-1-pshilov@microsoft.com> (raw)
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@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
---
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
next reply other threads:[~2019-10-31 21:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-31 21:18 Pavel Shilovsky [this message]
2019-11-03 2:06 ` [PATCH] CIFS: Fix SMB2 oplock break processing Steve French
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191031211857.18989-1-pshilov@microsoft.com \
--to=piastryyy@gmail.com \
--cc=linux-cifs@vger.kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.