Now that sparse has been fixed, it spotted a couple recent minor
endian errors (and removed one additional sparse warning).

Thanks to Luc Van Oostenryck for his help fixing sparse.
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

There may be situations when a server negotiates SMB 2.1
protocol version or higher but responds to a CREATE request
with an oplock rather than a lease.

Currently the client doesn't handle such a case correctly:
when another CREATE comes in the server sends an oplock
break to the initial CREATE and the client doesn't send
an ack back due to a wrong caching level being set (READ
instead of RWH). Missing an oplock break ack makes the
server wait until the break times out which dramatically
increases the latency of the second CREATE.

Fix this by properly detecting oplocks when using SMB 2.1
protocol version and higher.

Cc: <stable@vger.kernel.org>
Signed-off-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

Various SMB3 ACL related flags (for security descriptor and
ACEs for example) were missing and some fields are different
in SMB3 and CIFS. Update cifsacl.h definitions based on
current MS-DTYP specification.
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

We need to populate an ACL (security descriptor open context)
on file and directory correct.  This patch passes in the
mode.  Followon patch will build the open context and the
security descriptor (from the mode) that goes in the open
context.
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

Additional reparse tags were described for WSL and file sync.
Add missing defines for these tags. Some will be useful for
POSIX extensions (as discussed at Storage Developer Conference).
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>

It should not be larger then the slab max buf size. If user
specifies a larger size, it passes this check and goes
straightly to SMB2_set_info_init performing an insecure memcpy.
Signed-off-by: NMurphy Zhou <jencce.kernel@gmail.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Fixes gcc '-Wunused-but-set-variable' warning:

fs/cifs/sess.c: In function sess_auth_lanman:
fs/cifs/sess.c:910:8: warning: variable capabilities set but not used [-Wunused-but-set-variable]
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: Nzhengbin <zhengbin13@huawei.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Fix sparse warnings:

fs/cifs/smb2pdu.c:3200:1: warning: symbol 'SMB2_notify_init' was not declared. Should it be static?
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: Nzhengbin <zhengbin13@huawei.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

We were not bumping up the "open on server" (num_remote_opens)
counter (in some cases) on opens of the share root so
could end up showing as a negative value.

CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

In order to debug certain problems it is important to be able
to decrypt network traces (e.g. wireshark) but to do this we
need to be able to dump out the encryption/decryption keys.
Dumping them to an ioctl is safer than dumping then to dmesg,
(and better than showing all keys in a pseudofile).

Restrict this to root (CAP_SYS_ADMIN), and only for a mount
that this admin has access to.

Sample smbinfo output:
SMB3.0 encryption
Session Id:   0x82d2ec52
Session Key:  a5 6d 81 d0 e c1 ca e1 d8 13 aa 20 e8 f2 cc 71
Server Encryption Key:  1a c3 be ba 3d fc dc 3c e bc 93 9e 50 9e 19 c1
Server Decryption Key:  e0 d4 d9 43 1b a2 1b e3 d8 76 77 49 56 f7 20 88
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

To 2.23
Signed-off-by: NSteve French <stfrench@microsoft.com>

DACL should start with mode ACE first but we are putting it at the
end. reorder them to put it first.
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

make cifs more verbose about buffer size errors
and add some comments
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

SMB3 change notify is important to allow applications to wait
on directory change events of different types (e.g. adding
and deleting files from others systems). Add worker functions
for this.
Acked-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Introduce a new CONFIG_CIFS_ROOT option to handle root file systems
over a SMB share.

In order to mount the root file system during the init process, make
cifs.ko perform non-blocking socket operations while mounting and
accessing it.

Cc: Steve French <smfrench@gmail.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NPaulo Alcantara (SUSE) <paulo@paulo.ac>
Signed-off-by: NSteve French <stfrench@microsoft.com>

when mounting with modefromsid, we end up writing 4 ACE in a security
descriptor that only has room for 3, thus triggering an out-of-bounds
write. fix this by changing the min size of a security descriptor.
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

commit a091c5f67c99 ("smb3: allow parallelizing decryption of reads")
had a potential null dereference
Reported-by: Nkbuild test robot <lkp@intel.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Suggested-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

An earlier patch "CIFS: fix deadlock in cached root handling"
did not completely address the deadlock in open_shroot. This
patch addresses the deadlock.

In testing the recent patch:
  smb3: improve handling of share deleted (and share recreated)
we were able to reproduce the open_shroot deadlock to one
of the target servers in unmount in a delete share scenario.

Fixes: 7e5a70ad ("CIFS: fix deadlock in cached root handling")

This is version 2 of this patch. An earlier version of this
patch "smb3: fix unmount hang in open_shroot" had a problem
found by Dan.
Reported-by: Nkbuild test robot <lkp@intel.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Suggested-by: NPavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
CC: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>

In some cases to work around server bugs or performance
problems it can be helpful to be able to disable requesting
SMB2.1/SMB3 leases on a particular mount (not to all servers
and all shares we are mounted to). Add new mount parm
"nolease" which turns off requesting leases on directory
or file opens.  Currently the only way to disable leases is
globally through a module load parameter. This is more
granular.
Suggested-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>

When a share is deleted, returning EIO is confusing and no useful
information is logged.  Improve the handling of this case by
at least logging a better error for this (and also mapping the error
differently to EREMCHG).  See e.g. the new messages that would be logged:

[55243.639530] server share \\192.168.1.219\scratch deleted
[55243.642568] CIFS VFS: \\192.168.1.219\scratch BAD_NETWORK_NAME: \\192.168.1.219\scratch

In addition for the case where a share is deleted and then recreated
with the same name, have now fixed that so it works. This is sometimes
done for example, because the admin had to move a share to a different,
bigger local drive when a share is running low on space.
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

Displayed in /proc/fs/cifs/Stats once for each
socket we are connected to.

This allows us to find out what the maximum number of
requests that had been in flight (at any one time). Note that
/proc/fs/cifs/Stats can be reset if you want to look for
maximum over a small period of time.

Sample output (immediately after mount):

Resources in use
CIFS Session: 1
Share (unique mount targets): 2
SMB Request/Response Buffer: 1 Pool size: 5
SMB Small Req/Resp Buffer: 1 Pool size: 30
Operations (MIDs): 0

0 session 0 share reconnects
Total vfs operations: 5 maximum at one time: 2

Max requests in flight: 2
1) \\localhost\scratch
SMBs: 18
Bytes read: 0  Bytes written: 0
...
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

No point in offloading read decryption if no other requests on the
wire
Signed-off-by: NSteve French <stfrench@microsoft.com>
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>

and convert smb2_query_path_info() to use it.
This will eliminate the need for a SMB2_Create when we already have an
open handle that can be used. This will also prevent a oplock break
in case the other handle holds a lease.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Disable offload of the decryption of encrypted read responses
by default (equivalent to setting this new mount option "esize=0").

Allow setting the minimum encrypted read response size that we
will choose to offload to a worker thread - it is now configurable
via on a new mount option "esize="

Depending on which encryption mechanism (GCM vs. CCM) and
the number of reads that will be issued in parallel and the
performance of the network and CPU on the client, it may make
sense to enable this since it can provide substantial benefit when
multiple large reads are in flight at the same time.
Signed-off-by: NSteve French <stfrench@microsoft.com>
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>

decrypting large reads on encrypted shares can be slow (e.g. adding
multiple milliseconds per-read on non-GCM capable servers or
when mounting with dialects prior to SMB3.1.1) - allow parallelizing
of read decryption by launching worker threads.

Testing to Samba on localhost showed 25% improvement.
Testing to remote server showed very large improvement when
doing more than one 'cp' command was called at one time.
Signed-off-by: NSteve French <stfrench@microsoft.com>
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>

Where we have a tcon available we can log \\server\share as part
of the message. Only do this for the VFS log level.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Code cleanup in the 5.1 kernel changed the array
passed into signing verification on large reads leading
to warning messages being logged when copying files to local
systems from remote.

   SMB signature verification returned error = -5

This changeset fixes verification of SMB3 signatures of large
reads.
Suggested-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

Add new mount option "signloosely" which enables signing but skips the
sometimes expensive signing checks in the responses (signatures are
calculated and sent correctly in the SMB2/SMB3 requests even with this
mount option but skipped in the responses).  Although weaker for security
(and also data integrity in case a packet were corrupted), this can provide
enough of a performance benefit (calculating the signature to verify a
packet can be expensive especially for large packets) to be useful in
some cases.
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

We only had dynamic tracepoints on errors in flush
and close, but may be helpful to trace enter
and non-error exits for those.  Sample trace examples
(excerpts) from "cp" and "dd" show two of the new
tracepoints.

  cp-22823 [002] .... 123439.179701: smb3_enter: _cifsFileInfo_put: xid=10
  cp-22823 [002] .... 123439.179705: smb3_close_enter: xid=10 sid=0x98871327 tid=0xfcd585ff fid=0xc7f84682
  cp-22823 [002] .... 123439.179711: smb3_cmd_enter: sid=0x98871327 tid=0xfcd585ff cmd=6 mid=43
  cp-22823 [002] .... 123439.180175: smb3_cmd_done: sid=0x98871327 tid=0xfcd585ff cmd=6 mid=43
  cp-22823 [002] .... 123439.180179: smb3_close_done: xid=10 sid=0x98871327 tid=0xfcd585ff fid=0xc7f84682

  dd-22981 [003] .... 123696.946011: smb3_flush_enter: xid=24 sid=0x98871327 tid=0xfcd585ff fid=0x1917736f
  dd-22981 [003] .... 123696.946013: smb3_cmd_enter: sid=0x98871327 tid=0xfcd585ff cmd=7 mid=123
  dd-22981 [003] .... 123696.956639: smb3_cmd_done: sid=0x98871327 tid=0x0 cmd=7 mid=123
  dd-22981 [003] .... 123696.956644: smb3_flush_done: xid=24 sid=0x98871327 tid=0xfcd585ff fid=0x1917736f
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

If the server config (e.g. Samba smb.conf "csc policy = disable)
for the share indicates that the share should not be cached, log
a warning message if forced client side caching ("cache=ro" or
"cache=singleclient") is requested on mount.
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

If a share is known to be only to be accessed by one client, we
can aggressively cache writes not just reads to it.

Add "cache=" option (cache=singleclient) for mounting read write shares
(that will not be read or written to from other clients while we have
it mounted) in order to improve performance.
Signed-off-by: NSteve French <stfrench@microsoft.com>

Add some additional logging so the user can see if the share they
mounted with cache=ro is considered read only by the server

CIFS: Attempting to mount //localhost/test
CIFS VFS: mounting share with read only caching. Ensure that the share will not be modified while in use.
CIFS VFS: read only mount of RW share

CIFS: Attempting to mount //localhost/test-ro
CIFS VFS: mounting share with read only caching. Ensure that the share will not be modified while in use.
CIFS VFS: mounted to read only share
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

If a share is immutable (at least for the period that it will
be mounted) it would be helpful to not have to revalidate
dentries repeatedly that we know can not be changed remotely.

Add "cache=" option (cache=ro) for mounting read only shares
in order to improve performance in cases in which we know that
the share will not be changing while it is in use.
Signed-off-by: NSteve French <stfrench@microsoft.com>

The assignment of pointer server dereferences pointer ses, however,
this dereference occurs before ses is null checked and hence we
have a potential null pointer dereference.  Fix this by only
dereferencing ses after it has been null checked.

Addresses-Coverity: ("Dereference before null check")
Fixes: 2808c6639104 ("cifs: add new debugging macro cifs_server_dbg")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

which can be used from contexts where we have a TCP_Server_Info *server.
This new macro will prepend the debugging string with "Server:<servername> "
which will help when debugging issues on hosts with many cifs connections
to several different servers.

Convert a bunch of cifs_dbg(VFS) calls to cifs_server_dbg(VFS)
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

If we already have a writable handle for a path we want to set the
attributes for then use that instead of a create/set-info/close compound.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

rename() takes a path for old_file and in SMB2 we used to just create
a compound for create(old_path)/rename/close().
If we already have a writable handle we can avoid the create() and close()
altogether and just use the existing handle.

For this situation, as we avoid doing the create()
we also avoid triggering an oplock break for the existing handle.
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Fixes gcc '-Wunused-but-set-variable' warning:

fs/cifs/file.c: In function cifs_lock:
fs/cifs/file.c:1696:24: warning: variable cinode set but not used [-Wunused-but-set-variable]
fs/cifs/file.c: In function cifs_write:
fs/cifs/file.c:1765:23: warning: variable cifs_sb set but not used [-Wunused-but-set-variable]
fs/cifs/file.c: In function collect_uncached_read_data:
fs/cifs/file.c:3578:20: warning: variable tcon set but not used [-Wunused-but-set-variable]

'cinode' is never used since introduced by
commit 03776f45 ("CIFS: Simplify byte range locking code")
'cifs_sb' is not used since commit cb7e9eab ("CIFS: Use
multicredits for SMB 2.1/3 writes").
'tcon' is not used since commit d26e2903 ("smb3: fix bytes_read statistics")
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

It is not null terminated (length was off by two).

Also see similar change to Samba:

https://gitlab.com/samba-team/samba/merge_requests/666Reported-by: NStefan Metzmacher <metze@samba.org>
Signed-off-by: NSteve French <stfrench@microsoft.com>

In smb3_punch_hole, variable cifsi set but not used, remove it.
In cifs_lock, variable netfid set but not used, remove it.
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: Nzhengbin <zhengbin13@huawei.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>