[PATCH 6.10 2/9] cifs: Fix missing error code set

[PATCH 6.10 2/9] cifs: Fix missing error code set

[Greg Kroah-Hartman]

6.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <dhowells@redhat.com>

commit d2c5eb57b6da10f335c30356f9696bd667601e6a upstream.

In cifs_strict_readv(), the default rc (-EACCES) is accidentally cleared by
a successful return from netfs_start_io_direct(), such that if
cifs_find_lock_conflict() fails, we don't return an error.

Fix this by resetting the default error code.

Fixes: 14b1cd25346b ("cifs: Fix locking in cifs_strict_readv()")
Cc: stable@vger.kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/client/file.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index 1374635e89fa..6178c6d8097d 100644
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -2877,6 +2877,7 @@ cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
 		rc = netfs_start_io_direct(inode);
 		if (rc < 0)
 			goto out;
+		rc = -EACCES;
 		down_read(&cinode->lock_sem);
 		if (!cifs_find_lock_conflict(
 			    cfile, iocb->ki_pos, iov_iter_count(to),
@@ -2889,6 +2890,7 @@ cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
 		rc = netfs_start_io_read(inode);
 		if (rc < 0)
 			goto out;
+		rc = -EACCES;
 		down_read(&cinode->lock_sem);
 		if (!cifs_find_lock_conflict(
 			    cfile, iocb->ki_pos, iov_iter_count(to),
-- 
2.45.2

[PATCH 6.10 3/9] cifs: Fix missing fscache invalidation

[Greg Kroah-Hartman]

6.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <dhowells@redhat.com>

commit a07d38afd15281c42613943a9a715c3ba07c21e6 upstream.

A network filesystem needs to implement a netfslib hook to invalidate
fscache if it's to be able to use the cache.

Fix cifs to implement the cache invalidation hook.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 3ee1a1fc3981 ("cifs: Cut over to using netfslib")
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/client/file.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -123,6 +123,11 @@ fail:
 	goto out;
 }
 
+static void cifs_netfs_invalidate_cache(struct netfs_io_request *wreq)
+{
+	cifs_invalidate_cache(wreq->inode, 0);
+}
+
 /*
  * Split the read up according to how many credits we can get for each piece.
  * It's okay to sleep here if we need to wait for more credit to become
@@ -307,6 +312,7 @@ const struct netfs_request_ops cifs_req_
 	.begin_writeback	= cifs_begin_writeback,
 	.prepare_write		= cifs_prepare_write,
 	.issue_write		= cifs_issue_write,
+	.invalidate_cache	= cifs_netfs_invalidate_cache,
 };
 
 /*

[PATCH 6.10 5/9] cifs: Fix server re-repick on subrequest retry

[Greg Kroah-Hartman]

6.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <dhowells@redhat.com>

commit de40579b903883274fe203865f29d66b168b7236 upstream.

When a subrequest is marked for needing retry, netfs will call
cifs_prepare_write() which will make cifs repick the server for the op
before renegotiating credits; it then calls cifs_issue_write() which
invokes smb2_async_writev() - which re-repicks the server.

If a different server is then selected, this causes the increment of
server->in_flight to happen against one record and the decrement to happen
against another, leading to misaccounting.

Fix this by just removing the repick code in smb2_async_writev().  As this
is only called from netfslib-driven code, cifs_prepare_write() should
always have been called first, and so server should never be NULL and the
preparatory step is repeated in the event that we do a retry.

The problem manifests as a warning looking something like:

 WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs]
 ...
 RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs]
 ...
  smb2_writev_callback+0x334/0x560 [cifs]
  cifs_demultiplex_thread+0x77a/0x11b0 [cifs]
  kthread+0x187/0x1d0
  ret_from_fork+0x34/0x60
  ret_from_fork_asm+0x1a/0x30

Which may be triggered by a number of different xfstests running against an
Azure server in multichannel mode.  generic/249 seems the most repeatable,
but generic/215, generic/249 and generic/308 may also show it.

Fixes: 3ee1a1fc3981 ("cifs: Cut over to using netfslib")
Cc: stable@vger.kernel.org
Reported-by: Steve French <smfrench@gmail.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Aurelien Aptel <aaptel@suse.com>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/client/smb2pdu.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index 2ae2dbb6202b..bb84a89e5905 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -4859,9 +4859,6 @@ smb2_async_writev(struct cifs_io_subrequest *wdata)
 	struct cifs_io_parms *io_parms = NULL;
 	int credit_request;
 
-	if (!wdata->server || test_bit(NETFS_SREQ_RETRYING, &wdata->subreq.flags))
-		server = wdata->server = cifs_pick_channel(tcon->ses);
-
 	/*
 	 * in future we may get cifs_io_parms passed in from the caller,
 	 * but for now we construct it here...
-- 
2.45.2

[PATCH 6.10 6/9] cifs: Fix setting of zero_point after DIO write

[Greg Kroah-Hartman]

6.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <dhowells@redhat.com>

commit 61ea6b3a3104fcd66364282391dd2152bc4c129a upstream.

At the moment, at the end of a DIO write, cifs calls netfs_resize_file() to
adjust the size of the file if it needs it.  This will reduce the
zero_point (the point above which we assume a read will just return zeros)
if it's more than the new i_size, but won't increase it.

With DIO writes, however, we definitely want to increase it as we have
clobbered the local pagecache and then written some data that's not
available locally.

Fix cifs to make the zero_point above the end of a DIO or unbuffered write.

This fixes corruption seen occasionally with the generic/708 xfs-test.  In
that case, the read-back of some of the written data is being
short-circuited and replaced with zeroes.

Fixes: 3ee1a1fc3981 ("cifs: Cut over to using netfslib")
Cc: stable@vger.kernel.org
Reported-by: Steve French <sfrench@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/client/file.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -2364,13 +2364,18 @@ void cifs_write_subrequest_terminated(st
 				      bool was_async)
 {
 	struct netfs_io_request *wreq = wdata->rreq;
-	loff_t new_server_eof;
+	struct netfs_inode *ictx = netfs_inode(wreq->inode);
+	loff_t wrend;
 
 	if (result > 0) {
-		new_server_eof = wdata->subreq.start + wdata->subreq.transferred + result;
+		wrend = wdata->subreq.start + wdata->subreq.transferred + result;
 
-		if (new_server_eof > netfs_inode(wreq->inode)->remote_i_size)
-			netfs_resize_file(netfs_inode(wreq->inode), new_server_eof, true);
+		if (wrend > ictx->zero_point &&
+		    (wdata->rreq->origin == NETFS_UNBUFFERED_WRITE ||
+		     wdata->rreq->origin == NETFS_DIO_WRITE))
+			ictx->zero_point = wrend;
+		if (wrend > ictx->remote_i_size)
+			netfs_resize_file(ictx, wrend, true);
 	}
 
 	netfs_write_subrequest_terminated(&wdata->subreq, result, was_async);