Since IPC now has a tcon object, the caller can just pass it. This
allows domain-based DFS requests to work with smb2+.

Link: https://bugzilla.samba.org/show_bug.cgi?id=12917
Fixes: 9d49640a ("CIFS: implement get_dfs_refer for SMB2+")
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

* Remove ses->ipc_tid.
* Make IPC$ regular tcon.
* Add a direct pointer to it in ses->tcon_ipc.
* Distinguish PIPE tcon from IPC tcon by adding a tcon->pipe flag. All
  IPC tcons are pipes but not all pipes are IPC.
* All TreeConnect functions now cannot take a NULL tcon object.

The IPC tcon has the same lifetime as the session it belongs to. It is
created when the session is created and destroyed when the session is
destroyed.

Since no mounts directly refer to the IPC tcon, its refcount should
always be set to initialisation value (1). Thus we make sure
cifs_put_tcon() skips it.

If the mount request resulting in a new session being created requires
encryption, try to require it too for IPC.

* set SERVER_NAME_LENGTH to serverName actual size

The maximum length of an ipv6 string representation is defined in
INET6_ADDRSTRLEN as 45+1 for null but lets keep what we know works.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

Node is assigned twice to rb_first(root), first during declaration
time and second after a taking a spin lock, so we have a duplicated
assignment.  Remove the first assignment because it is redundant and
also not protected by the spin lock.

Cleans up clang warning:
fs/cifs/connect.c:4435:18: warning: Value stored to 'node' during
its initialization is never read
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

GCC versions from 4.9 to 6.3 produce a false-positive warning when
dealing with a conditional spin_lock_irqsave():

fs/cifs/smbdirect.c: In function 'smbd_recv_buf':
include/linux/spinlock.h:260:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]

This function calls some sleeping interfaces, so it is clear that it
does not get called with interrupts disabled and there is no need
to save the irq state before taking the spinlock. This lets us
remove the variable, which makes the function slightly more efficient
and avoids the warning.

A further cleanup could do the same change for other functions in this
file, but I did not want to take this too far for now.

Fixes: ac69f66e54ca ("CIFS: SMBD: Implement function to receive data via RDMA receive")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steve French <smfrench@gmail.com>

Autonegotiation gives a security settings mismatch error if the SMB
server selects an SMBv3 dialect that isn't SMB3.02. The exact error is
"protocol revalidation - security settings mismatch".
This can be tested using Samba v4.2 or by setting the global Samba
setting max protocol = SMB3_00.

The check that fails in smb3_validate_negotiate is the dialect
verification of the negotiate info response. This is because it tries
to verify against the protocol_id in the global smbdefault_values. The
protocol_id in smbdefault_values is SMB3.02.
In SMB2_negotiate the protocol_id in smbdefault_values isn't updated,
it is global so it probably shouldn't be, but server->dialect is.

This patch changes the check in smb3_validate_negotiate to use
server->dialect instead of server->vals->protocol_id. The patch works
with autonegotiate and when using a specific version in the vers mount
option.
Signed-off-by: Daniel N Pettersson <danielnp@axis.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>

Fixes: 07495ff5d9bc ("CIFS: SMBD: Establish SMB Direct connection")
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Long Li <longli@microsoft.com>

Currently the CIFS SMB Direct implementation (experimental) doesn't properly
support signing. Disable it when SMB Direct is in use for transport.

Signing will be enabled in future after it is implemented.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

For debugging and troubleshooting, export SMBDirect debug counters to
/proc/fs/cifs/DebugData.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

If I/O size is larger than rdma_readwrite_threshold, use RDMA write for
SMB read by specifying channel SMB2_CHANNEL_RDMA_V1 or
SMB2_CHANNEL_RDMA_V1_INVALIDATE in the SMB packet, depending on SMB dialect
used. Append a smbd_buffer_descriptor_v1 to the end of the SMB packet and fill
in other values to indicate this SMB read uses RDMA write.

There is no need to read from the transport for incoming payload. At the time
SMB read response comes back, the data is already transferred and placed in the
pages by RDMA hardware.

When SMB read is finished, deregister the memory regions if RDMA write is used
for this SMB read. smbd_deregister_mr may need to do local invalidation and
sleep, if server remote invalidation is not used.

There are situations where the MID may not be created on I/O failure, under
which memory region is deregistered when read data context is released.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

This patch is for preparing upper layer doing SMB read via RDMA write.

When RDMA write is used for SMB read, the returned data length is in
DataRemaining in the response packet. Reading it properly by adding a
parameter to specifiy where the returned data length is.

Add the defition for memory registration to wdata and return the correct
length based on if RDMA write is used.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

When sending I/O, if size is larger than rdma_readwrite_threshold we prepare
to send SMB write packet for a RDMA read via memory registration. The actual
I/O is done by remote peer through local RDMA hardware. Modify the relevant
fields in the packet accordingly, and append a smbd_buffer_descriptor_v1 to
the end of the SMB write packet.

On write I/O finish, deregister the memory region if this was for a RDMA read.
If remote invalidation is not used, the call to smbd_deregister_mr will do
local invalidation and possibly wait. Memory region is normally deregistered
in MID callback as soon as it's used. There are situations where the MID may
not be created on I/O failure, under which memory region is deregistered when
write data context is released.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

Memory registration is used for transferring payload via RDMA read or write.
After I/O is done, memory registrations are recovered and reused. This
process can be time consuming and is done in a work queue.
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

With SMB Direct connected, use it for sending data via RDMA send.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

The transport doesn't maintain send buffers or send queue for transferring
payload via RDMA send. There is no data copy in the transport on send.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

With SMB Direct connected, use it for receiving data via RDMA receive.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

On the receive path, the transport maintains receive buffers and a reassembly
queue for transferring payload via RDMA recv. There is data copy in the
transport on recv when it copies the payload to upper layer.

The transport recognizes the RFC1002 header length use in the SMB
upper layer payloads in CIFS. Because this length is mainly used for TCP and
not applicable to RDMA, it is handled as a out-of-band information and is
never sent over the wire, and the trasnport behaves like TCP to upper layer
by processing and exposing the length correctly on data payloads.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

When connecting over SMB Direct, the transport negotiates its maximum I/O sizes
with the server and determines how to choose to do RDMA send/recv vs
read/write. Expose these maximum I/O sizes to upper layer so we will get the
correct sized payloads.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

When upper layer wants to umount, make it call shutdown on transport when
SMB Direct is used.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

Add function to tear down a SMB Direct connection. This is used by upper layer
to free all SMB Direct connection and transport resources.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

Do a reconnect on SMB Direct when it is used as the connection. Reconnect can
happen for many reasons and it's mostly the decision of SMB2 upper layer.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

Add function to implement a reconnect to SMB Direct. This involves tearing down
the current connection and establishing/negotiating a new connection.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

When "rdma" is specified in the mount option, make CIFS connect to
SMB Direct.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

Prevent build errors when CIFS=y and INFINIBAND=m.

fs/cifs/smbdirect.o: In function `smbd_qp_async_error_upcall':
smbdirect.c:(.text+0x28c): undefined reference to `ib_event_msg'
fs/cifs/smbdirect.o: In function `smbd_destroy_rdma_work':
smbdirect.c:(.text+0xfde): undefined reference to `ib_drain_qp'
smbdirect.c:(.text+0xfea): undefined reference to `rdma_destroy_qp'
smbdirect.c:(.text+0x12a0): undefined reference to `ib_free_cq'
smbdirect.c:(.text+0x12ac): undefined reference to `ib_free_cq'
smbdirect.c:(.text+0x12b8): undefined reference to `ib_dealloc_pd'
smbdirect.c:(.text+0x12c4): undefined reference to `rdma_destroy_id'
fs/cifs/smbdirect.o: In function `_smbd_get_connection':
smbdirect.c:(.text+0x168c): undefined reference to `rdma_create_id'
smbdirect.c:(.text+0x1713): undefined reference to `rdma_resolve_addr'
smbdirect.c:(.text+0x1780): undefined reference to `rdma_resolve_route'
smbdirect.c:(.text+0x17e3): undefined reference to `rdma_destroy_id'
smbdirect.c:(.text+0x183d): undefined reference to `rdma_destroy_id'
smbdirect.c:(.text+0x199d): undefined reference to `ib_alloc_cq'
smbdirect.c:(.text+0x19d9): undefined reference to `ib_alloc_cq'
smbdirect.c:(.text+0x1a89): undefined reference to `rdma_create_qp'
smbdirect.c:(.text+0x1b3c): undefined reference to `rdma_connect'
smbdirect.c:(.text+0x2538): undefined reference to `rdma_destroy_qp'
smbdirect.c:(.text+0x2549): undefined reference to `ib_free_cq'
smbdirect.c:(.text+0x255a): undefined reference to `ib_free_cq'
smbdirect.c:(.text+0x2563): undefined reference to `ib_dealloc_pd'
smbdirect.c:(.text+0x256c): undefined reference to `rdma_destroy_id'
smbdirect.c:(.text+0x25f0): undefined reference to `__ib_alloc_pd'
smbdirect.c:(.text+0x26bb): undefined reference to `rdma_disconnect'
fs/cifs/smbdirect.o: In function `smbd_disconnect_rdma_work':
smbdirect.c:(.text+0x62): undefined reference to `rdma_disconnect'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc:	Steve French <sfrench@samba.org>
Cc:	linux-cifs@vger.kernel.org
Cc:	samba-technical@lists.samba.org (moderated for non-subscribers)
Signed-off-by: Steve French <smfrench@gmail.com>

If cifs_zap_mapping() returned an error, we would return without putting
the xid that we got earlier.  Restructure cifs_file_strict_mmap() and
cifs_file_mmap() to be more similar to each other and have a single
point of return that always puts the xid.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>

For use-configurable SMB Direct protocol values, export them to /proc/fs/cifs.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

The upper layer calls this function to connect to peer through SMB Direct.
Each SMB Direct connection is based on a RDMA RC Queue Pair.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

Add code to implement the core functions to establish a SMB Direct connection.

1. Establish an RDMA connection to SMB server.
2. Negotiate and setup SMB Direct protocol.
3. Implement idle connection timer and credit management.

SMB Direct is enabled by setting CONFIG_CIFS_SMB_DIRECT.

Add to Makefile to enable building SMB Direct.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

To prepare for protocol implementation, add constants and user-configurable
values for the SMB Direct protocol.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

Add "rdma" to CIFS mount options to connect to SMB Direct.
Add checks to validate this is used on SMB 3.X dialects.

To connect to SMBDirect, use "mount.cifs -o rdma,vers=3.x".
At the time of this patch, 3.x can be 3.0, 3.02 or 3.1.1.
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>

Build SMB Direct code when this option is set.
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>

This patch is for preparing upper layer for doing SMB read via RDMA write.

When we assemble the SMB read packet header, we need to know the I/O layout
if this request is to use a RDMA write. rdata has all the information we need
for memory registration. Add rdata to smb2_new_read_req.
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>

In both functions, use an array of 8 (arbitrary but should be big enough
for all current uses) iov and avoid having to kmalloc the array
for the common case.

If 8 is too small, then fall back to the original behaviour and use
kmalloc/kfree.

This should not change any behaviour but should save us a tiny amount of
cpu cycles.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>