[5.15 Backport] cifs: Check the lease context if we actually got a lease

[5.15 Backport] cifs: Check the lease context if we actually got a lease

[meetakshisetiyaoss]

This patch fixes a directory lease bug on the smb client and
prevents it from incorrectly caching the directories if the
server returns an invalid lease state. The patch is in
6.3 kernel, requesting backport to stable 5.15.
I have cherry-picked the patch for 5.15 kernel below

From 2bb51b129ceb884145c3527f8c04817cc00d0e6e Mon Sep 17 00:00:00 2001
From: Ronnie Sahlberg <lsahlber@redhat.com>
Date: Fri, 17 Feb 2023 13:35:00 +1000
Subject: [PATCH] cifs: Check the lease context if we actually got a lease

Some servers may return that we got a lease in rsp->OplockLevel
but then in the lease context contradict this and say we got no lease
at all.  Thus we need to check the context if we have a lease.
Additionally, If we do not get a lease we need to make sure we close
the handle before we return an error to the caller.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Meetakshi Setiya <msetiya@microsoft.com>
---
 fs/cifs/smb2ops.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index b725bd3144fb..6c30fff8a029 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -886,8 +886,6 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 		goto oshr_exit;
 	}
 
-	atomic_inc(&tcon->num_remote_opens);
-
 	o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
 	oparms.fid->persistent_fid = o_rsp->PersistentFileId;
 	oparms.fid->volatile_fid = o_rsp->VolatileFileId;
@@ -897,8 +895,6 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 
 	tcon->crfid.tcon = tcon;
 	tcon->crfid.is_valid = true;
-	tcon->crfid.dentry = dentry;
-	dget(dentry);
 	kref_init(&tcon->crfid.refcount);
 
 	/* BB TBD check to see if oplock level check can be removed below */
@@ -907,14 +903,16 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 		 * See commit 2f94a3125b87. Increment the refcount when we
 		 * get a lease for root, release it if lease break occurs
 		 */
-		kref_get(&tcon->crfid.refcount);
-		tcon->crfid.has_lease = true;
 		rc = smb2_parse_contexts(server, rsp_iov,
 				&oparms.fid->epoch,
 				    oparms.fid->lease_key, &oplock,
 				    NULL, NULL);
 		if (rc)
 			goto oshr_exit;
+
+		if (!(oplock & SMB2_LEASE_READ_CACHING_HE))
+			goto oshr_exit;
+
 	} else
 		goto oshr_exit;
 
@@ -928,7 +926,10 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 				(char *)&tcon->crfid.file_all_info))
 		tcon->crfid.file_all_info_is_valid = true;
 	tcon->crfid.time = jiffies;
-
+	tcon->crfid.dentry = dentry;
+	dget(dentry);
+	kref_get(&tcon->crfid.refcount);
+	tcon->crfid.has_lease = true;
 
 oshr_exit:
 	mutex_unlock(&tcon->crfid.fid_mutex);
@@ -937,8 +938,15 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 	SMB2_query_info_free(&rqst[1]);
 	free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
 	free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
-	if (rc == 0)
+	if (rc) {
+		if (tcon->crfid.is_valid)
+			SMB2_close(0, tcon, oparms.fid->persistent_fid,
+				   oparms.fid->volatile_fid);
+	}
+	if (rc == 0) {
 		*cfid = &tcon->crfid;
+		atomic_inc(&tcon->num_remote_opens);
+	}
 	return rc;
 }
 
-- 
2.46.0.46.g406f326d27

Re: [5.15 Backport] cifs: Check the lease context if we actually got a lease

[Greg KH]

On Fri, Sep 06, 2024 at 06:20:18AM -0400, meetakshisetiyaoss@gmail.com wrote:
> This patch fixes a directory lease bug on the smb client and
> prevents it from incorrectly caching the directories if the
> server returns an invalid lease state. The patch is in
> 6.3 kernel, requesting backport to stable 5.15.
> I have cherry-picked the patch for 5.15 kernel below
> 
> >From 2bb51b129ceb884145c3527f8c04817cc00d0e6e Mon Sep 17 00:00:00 2001

What is the real git commit id of this change?

And what about 6.1.y?  You can't skip that or you would have a
regression when you upgrade as you shouldn't be using 5.15.y for much
longer, right?  :)

thanks,

greg k-h

Re: [5.15 Backport] cifs: Check the lease context if we actually got a lease

[Greg KH]

On Fri, Sep 06, 2024 at 04:07:59PM +0530, Meetakshi Setiya wrote:
> Upstream commit 66d45ca1350a3bb8d5f4db8879ccad3ed492337a
> 
> Yes, you are right, it would be good to backport to 6.1 as well.
> Please let me know if you need anything from me.

I need a working backport for 6.1.y before we can take this one.  Oh
wait, it's already in 6.1.16, a long time ago.

This will be fine, thanks.

greg k-h