cifs->master_tlink is NULL against Win Server 2016 (which is
strange.. not sure why) and is dereferenced in cifs_sb_master_tcon().

move master_tlink getter to cifsglob.h so it can be used from
smb2misc.c
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
Acked-by: NPavel Shilovsky <pshilov@microsoft.com>

Add a function to allocate wdata without allocating pages for data
transfer. This gives the caller an option to pass a number of pages that
point to the data buffer to write to.

wdata is reponsible for free those pages after it's done.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Add a function to allocate rdata without allocating pages for data
transfer. This gives the caller an option to pass a number of pages
that point to the data buffer.

rdata is still reponsible for free those pages after it's done.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

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

Signed-off-by: NSteve French <smfrench@gmail.com>

If "posix" (or synonym "unix" for backward compatibility) specified on mount,
and server advertises support for SMB3.11 POSIX negotiate context, then
enable the new posix extensions on the tcon.  This can be viewed by
looking for "posix" in the mount options displayed by /proc/mounts
for that mount (ie if posix extensions allowed by server and the
experimental POSIX extensions also requested on the mount by specifying
"posix" at mount time).

Also add check to warn user if conflicting unix/nounix or posix/noposix specified
on mount.
Signed-off-by: NSteve French <smfrench@gmail.com>

Unlike CIFS where UNIX/POSIX extensions had been negotiatable,
SMB3 did not have POSIX extensions yet.  Add the new SMB3.11
POSIX negotiate context to ask the server whether it can
support POSIX (and thus whether we can send the new POSIX open
context).
Signed-off-by: NSteve French <smfrench@gmail.com>

To improve security it may be helpful to have additional ways to restrict the
ability to override the default dialects (SMB2.1, SMB3 and SMB3.02) on mount
with old dialects (CIFS/SMB1 and SMB2) since vers=1.0 (CIFS/SMB1) and vers=2.0
are weaker and less secure.

Add a module parameter "disable_legacy_dialects"
(/sys/module/cifs/parameters/disable_legacy_dialects) which can be set to
1 (or equivalently Y) to forbid use of vers=1.0 or vers=2.0 on mount.

Also cleans up a few build warnings about globals for various module parms.
Signed-off-by: NSteve French <smfrench@gmail.com>

Note which ones of the module params are cifs dialect only
(N/A for default dialect now that has moved to SMB2.1 or later)
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

When direct I/O is used, the data buffer may not always align to page
boundaries. Introduce a page offset in transport data structures to
describe the location of the buffer within the page.

Also change the function to pass the page offset when sending data to
transport.
Signed-off-by: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

In SMB2_open(), if we got a lease we need to store this in the fid structure
or else we will never be able to map a lease break back to which file/fid
it applies to.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

and change the smb2 version to take heder_preamble_size into account
instead of hardcoding it as 4 bytes.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

We need a struct TCP_Server_Info *server to this method as it calls
calc_size. The calc_size method will soon be changed to also
take a server argument.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

In SMB2/SMB3 unlike in cifs we unnecessarily open the root of the share
over and over again in various places during mount and path revalidation
and also in statfs.  This patch cuts redundant traffic (opens and closes)
by simply keeping the directory handle for the root around (and reopening
it as needed on reconnect), so query calls don't require three round
trips to copmlete - just one, and eases load on network, client and
server (on mount alone, cuts network traffic by more than a third).

Also add a new cifs mount parm "nohandlecache" to allow users whose
servers might have resource constraints (eg in case they have a server
with so many users connecting to it that this extra handle per mount
could possibly be a resource concern).
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

and get rid of some more calls to get_rfc1002_length()
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

and get rid of some get_rfc1002_length() in smb2
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

SMB3.11 crypto and hash contexts were not being checked strictly enough.
Add parsing and validity checking for the security contexts in the SMB3.11
negotiate response.
Signed-off-by: NSteve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

Some servers return inode number zero for the root directory, which
causes ls to display incorrect data (missing "." and "..").

If the server returns zero for the inode number of the root directory,
fake an inode number for it.
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>

This variable is set to 4 for all protocol versions and replaces
the hardcoded constant 4 throughought the code.
This will later be updated to reflect whether a response packet
has a 4 byte length preamble or not once we start removing this
field from the SMB2+ dialects.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

SMB3.11 clients must implement pre-authentification integrity.

* new mechanism to certify requests/responses happening before Tree
  Connect.
* supersedes VALIDATE_NEGOTIATE
* fixes signing for SMB3.11
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

* prepare for SMB3.11 pre-auth integrity
* enable sha512 when SMB311 is enabled in Kconfig
* add sha512 as a soft dependency
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.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: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.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: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NRonnie 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: NLong Li <longli@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.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: NLong Li <longli@microsoft.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>

This is a pure automated search-and-replace of the internal kernel
superblock flags.

The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.

Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.

The script to do this was:

    # places to look in; re security/*: it generally should *not* be
    # touched (that stuff parses mount(2) arguments directly), but
    # there are two places where we really deal with superblock flags.
    FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
            include/linux/fs.h include/uapi/linux/bfs_fs.h \
            security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
    # the list of MS_... constants
    SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
          DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
          POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
          I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
          ACTIVE NOUSER"

    SED_PROG=
    for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done

    # we want files that contain at least one of MS_...,
    # with fs/namespace.c and fs/pnode.c excluded.
    L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')

    for f in $L; do sed -i $f $SED_PROG; done
Requested-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

SMB3.1.1 is most secure and recent dialect. Fixup labels and lengths
for sMB3.1.1 signing and encryption.
Signed-off-by: NSteve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>

With the need to discourage use of less secure dialect, SMB1 (CIFS),
we temporarily upgraded the dialect to SMB3 in 4.13, but since there
are various servers which only support SMB2.1 (2.1 is more secure
than CIFS/SMB1) but not optimal for a default dialect - add support
for multidialect negotiation.  cifs.ko will now request SMB2.1
or later (ie SMB2.1 or SMB3.0, SMB3.02) and the server will
pick the latest most secure one it can support.

In addition since we are sending multidialect negotiate, add
support for secure negotiate to validate that a man in the
middle didn't downgrade us.
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org> # 4.13+

This adds support for writing extended attributes on SMB2+ shares.
Attributes can be written using the setfattr command.

RH-bz: 1110709
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

Remove the CONFIG_CIFS_SMB2 ifdef and Kconfig option since they
must always be on now.

For various security reasons, SMB3 and later are STRONGLY preferred
over CIFS and older dialects, and SMB3 (and later) will now be
the default dialects so we do not want to allow them to be
ifdeffed out.

In the longer term, we may be able to make older CIFS support
disableable in Kconfig with a new set of #ifdef, but we always
want SMB3 and later support enabled.
Signed-off-by: NSteven French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

According to the MS-SMB2 spec (3.2.5.1.6) once the client receives
STATUS_NETWORK_SESSION_EXPIRED error code from a server it should
reconnect the current SMB session. Currently the client doesn't do
that. This can result in subsequent client requests failing by
the server. The patch adds an additional logic to the demultiplex
thread to identify expired sessions and reconnect them.

Cc: <stable@vger.kernel.org>
Signed-off-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Some minor cleanup of cifs query xattr functions (will also make
SMB3 xattr implementation cleaner as well).
Signed-off-by: NSteve French <steve.french@primarydata.com>

When the final cifsFileInfo_put() is called from cifsiod and an oplock
break work is queued, lockdep complains loudly:

 =============================================
 [ INFO: possible recursive locking detected ]
 4.11.0+ #21 Not tainted
 ---------------------------------------------
 kworker/0:2/78 is trying to acquire lock:
  ("cifsiod"){++++.+}, at: flush_work+0x215/0x350

 but task is already holding lock:
  ("cifsiod"){++++.+}, at: process_one_work+0x255/0x8e0

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock("cifsiod");
   lock("cifsiod");

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 2 locks held by kworker/0:2/78:
  #0:  ("cifsiod"){++++.+}, at: process_one_work+0x255/0x8e0
  #1:  ((&wdata->work)){+.+...}, at: process_one_work+0x255/0x8e0

 stack backtrace:
 CPU: 0 PID: 78 Comm: kworker/0:2 Not tainted 4.11.0+ #21
 Workqueue: cifsiod cifs_writev_complete
 Call Trace:
  dump_stack+0x85/0xc2
  __lock_acquire+0x17dd/0x2260
  ? match_held_lock+0x20/0x2b0
  ? trace_hardirqs_off_caller+0x86/0x130
  ? mark_lock+0xa6/0x920
  lock_acquire+0xcc/0x260
  ? lock_acquire+0xcc/0x260
  ? flush_work+0x215/0x350
  flush_work+0x236/0x350
  ? flush_work+0x215/0x350
  ? destroy_worker+0x170/0x170
  __cancel_work_timer+0x17d/0x210
  ? ___preempt_schedule+0x16/0x18
  cancel_work_sync+0x10/0x20
  cifsFileInfo_put+0x338/0x7f0
  cifs_writedata_release+0x2a/0x40
  ? cifs_writedata_release+0x2a/0x40
  cifs_writev_complete+0x29d/0x850
  ? preempt_count_sub+0x18/0xd0
  process_one_work+0x304/0x8e0
  worker_thread+0x9b/0x6a0
  kthread+0x1b2/0x200
  ? process_one_work+0x8e0/0x8e0
  ? kthread_create_on_node+0x40/0x40
  ret_from_fork+0x31/0x40

This is a real warning.  Since the oplock is queued on the same
workqueue this can deadlock if there is only one worker thread active
for the workqueue (which will be the case during memory pressure when
the rescuer thread is handling it).

Furthermore, there is at least one other kind of hang possible due to
the oplock break handling if there is only worker.  (This can be
reproduced without introducing memory pressure by having passing 1 for
the max_active parameter of cifsiod.) cifs_oplock_break() can wait
indefintely in the filemap_fdatawait() while the cifs_writev_complete()
work is blocked:

 sysrq: SysRq : Show Blocked State
   task                        PC stack   pid father
 kworker/0:1     D    0    16      2 0x00000000
 Workqueue: cifsiod cifs_oplock_break
 Call Trace:
  __schedule+0x562/0xf40
  ? mark_held_locks+0x4a/0xb0
  schedule+0x57/0xe0
  io_schedule+0x21/0x50
  wait_on_page_bit+0x143/0x190
  ? add_to_page_cache_lru+0x150/0x150
  __filemap_fdatawait_range+0x134/0x190
  ? do_writepages+0x51/0x70
  filemap_fdatawait_range+0x14/0x30
  filemap_fdatawait+0x3b/0x40
  cifs_oplock_break+0x651/0x710
  ? preempt_count_sub+0x18/0xd0
  process_one_work+0x304/0x8e0
  worker_thread+0x9b/0x6a0
  kthread+0x1b2/0x200
  ? process_one_work+0x8e0/0x8e0
  ? kthread_create_on_node+0x40/0x40
  ret_from_fork+0x31/0x40
 dd              D    0   683    171 0x00000000
 Call Trace:
  __schedule+0x562/0xf40
  ? mark_held_locks+0x29/0xb0
  schedule+0x57/0xe0
  io_schedule+0x21/0x50
  wait_on_page_bit+0x143/0x190
  ? add_to_page_cache_lru+0x150/0x150
  __filemap_fdatawait_range+0x134/0x190
  ? do_writepages+0x51/0x70
  filemap_fdatawait_range+0x14/0x30
  filemap_fdatawait+0x3b/0x40
  filemap_write_and_wait+0x4e/0x70
  cifs_flush+0x6a/0xb0
  filp_close+0x52/0xa0
  __close_fd+0xdc/0x150
  SyS_close+0x33/0x60
  entry_SYSCALL_64_fastpath+0x1f/0xbe

 Showing all locks held in the system:
 2 locks held by kworker/0:1/16:
  #0:  ("cifsiod"){.+.+.+}, at: process_one_work+0x255/0x8e0
  #1:  ((&cfile->oplock_break)){+.+.+.}, at: process_one_work+0x255/0x8e0

 Showing busy workqueues and worker pools:
 workqueue cifsiod: flags=0xc
   pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1
     in-flight: 16:cifs_oplock_break
     delayed: cifs_writev_complete, cifs_echo_request
 pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=0s workers=3 idle: 750 3

Fix these problems by creating a a new workqueue (with a rescuer) for
the oplock break work.
Signed-off-by: NRabin Vincent <rabinv@axis.com>
Signed-off-by: NSteve French <smfrench@gmail.com>
CC: Stable <stable@vger.kernel.org>

This patch adds support to process write calls passed by io_submit()
asynchronously. It based on the previously introduced async context
that allows to process i/o responses in a separate thread and
return the caller immediately for asynchronous calls.

This improves writing performance of single threaded applications
with increasing of i/o queue depth size.
Signed-off-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

This patch adds support to process read calls passed by io_submit()
asynchronously. It based on the previously introduced async context
that allows to process i/o responses in a separate thread and
return the caller immediately for asynchronous calls.

This improves reading performance of single threaded applications
with increasing of i/o queue depth size.
Signed-off-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Currently the code doesn't recognize asynchronous calls passed
by io_submit() and processes all calls synchronously. This is not
what kernel AIO expects. This patch introduces a new async context
that keeps track of all issued i/o requests and moves a response
collecting procedure to a separate thread. This allows to return
to a caller immediately for async calls and call iocb->ki_complete()
once all requests are completed. For sync calls the current thread
simply waits until all requests are completed.
Signed-off-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

STATUS_BAD_NETWORK_NAME can be received during node failover,
causing the flag to be set and making the reconnect thread
always unsuccessful, thereafter.

Once the only place where it is set is removed, the remaining
bits are rendered moot.

Removing it does not prevent "mount" from failing when a non
existent share is passed.

What happens when the share really ceases to exist while the
share is mounted is undefined now as much as it was before.
Signed-off-by: NGermano Percossi <germano.percossi@citrix.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

The earlier changes to copy range for cifs unintentionally disabled the more
common form of server side copy.

The patch introduces the file_operations helper cifs_copy_file_range()
which is used by the syscall copy_file_range. The new file operations
helper allows us to perform server side copies for SMB2.0 and 2.1
servers as well as SMB 3.0+ servers which do not support the ioctl
FSCTL_DUPLICATE_EXTENTS_TO_FILE.

The new helper uses the ioctl FSCTL_SRV_COPYCHUNK_WRITE to perform
server side copies. The helper is called by vfs_copy_file_range() only
once an attempt to clone the file using the ioctl
FSCTL_DUPLICATE_EXTENTS_TO_FILE has failed.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
CC: Stable  <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

Server side copy is one of the most important mechanisms smb2/smb3
supports and it was unintentionally disabled for most use cases.

Renaming calls to reflect the underlying smb2 ioctl called. This is
similar to the name duplicate_extents used for a similar ioctl which is
also used to duplicate files by reusing fs blocks. The name change is to
avoid confusion.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

A signal can interrupt a SendReceive call which result in incoming
responses to the call being ignored. This is a problem for calls such as
open which results in the successful response being ignored. This
results in an open file resource on the server.

The patch looks into responses which were cancelled after being sent and
in case of successful open closes the open fids.

For this patch, the check is only done in SendReceive2()

RH-bz: 1403319
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Cc: Stable <stable@vger.kernel.org>