Clarify comments for create contexts which we do send,
and fix typo in one create context definition and add
newer SMB3 create contexts to the list.
Signed-off-by: Steve French <smfrench@gmail.com>
Problem reported in Red Hat bz 1040329 for strict writes where we cache
only when we hold oplock and write direct to the server when we don't.
When we receive an oplock break, we first change the oplock value for
the inode in cifsInodeInfo->oplock to indicate that we no longer hold
the oplock before we enqueue a task to flush changes to the backing
device. Once we have completed flushing the changes, we return the
oplock to the server.
There are 2 ways here where we can have data corruption
1) While we flush changes to the backing device as part of the oplock
break, we can have processes write to the file. These writes check for
the oplock, find none and attempt to write directly to the server.
These direct writes made while we are flushing from cache could be
overwritten by data being flushed from the cache causing data
corruption.
2) While a thread runs in cifs_strict_writev, the machine could receive
and process an oplock break after the thread has checked the oplock and
found that it allows us to cache and before we have made changes to the
cache. In that case, we end up with a dirty page in cache when we
shouldn't have any. This will be flushed later and will overwrite all
subsequent writes to the part of the file represented by this page.
Before making any writes to the server, we need to confirm that we are
not in the process of flushing data to the server and if we are, we
should wait until the process is complete before we attempt the write.
We should also wait for existing writes to complete before we process
an oplock break request which changes oplock values.
We add a version specific downgrade_oplock() operation to allow for
differences in the oplock values set for the different smb versions.
Cc: stable@vger.kernel.org
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
SMB3 servers can respond with MaxTransactSize of more than 4M
that can cause a memory allocation error returned from kmalloc
in a lock codepath. Also the client doesn't support multicredit
requests now and allows buffer sizes of 65536 bytes only. Set
MaxTransactSize to this maximum supported value.
Cc: stable@vger.kernel.org # 3.7+
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
When we are running SMB3 or SMB3.02 connections which are signed
we need to validate the protocol negotiation information,
to ensure that the negotiate protocol response was not tampered with.
Add the missing FSCTL which is sent at mount time (immediately after
the SMB3 Tree Connect) to validate that the capabilities match
what we think the server sent.
"Secure dialect negotiation is introduced in SMB3 to protect against
man-in-the-middle attempt to downgrade dialect negotiation.
The idea is to prevent an eavesdropper from downgrading the initially
negotiated dialect and capabilities between the client and the server."
For more explanation see 2.2.31.4 of MS-SMB2 or
http://blogs.msdn.com/b/openspecification/archive/2012/06/28/smb3-secure-dialect-negotiation.aspx
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
This third version of the patch, incorparating feedback from David Disseldorp
extends the ability of copychunk (refcopy) over smb2/smb3 mounts to
handle servers with smaller than usual maximum chunk sizes
and also fixes it to handle files bigger than the maximum chunk sizes
In the future this can be extended further to handle sending
multiple chunk requests in on SMB2 ioctl request which will
further improve performance, but even with one 1MB chunk per
request the speedup on cp is quite large.
Reviewed-by: David Disseldorp <ddiss@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
This first patch adds the ability for us to do a server side copy
(ie fast copy offloaded to the server to perform, aka refcopy)
"cp --reflink"
of one file to another located on the same server. This
is much faster than traditional copy (which requires
reading and writing over the network and extra
memcpys).
This first version is not going to be copy
files larger than about 1MB (to Samba) until I add
support for multiple chunks and for autoconfiguring
the chunksize.
It includes:
1) processing of the ioctl
2) marshalling and sending the SMB2/SMB3 fsctl over the network
3) simple parsing of the response
It does not include yet (these will be in followon patches to come soon):
1) support for multiple chunks
2) support for autoconfiguring and remembering the chunksize
3) Support for the older style copychunk which Samba 4.1 server supports
(because this requires write permission on the target file, which
cp does not give you, apparently per-posix). This may require
a distinct tool (other than cp) and other ioctl to implement.
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
When CONFIG_CIFS_STATS2 enabled query adapter info for debugging
It is easy now in SMB3 to query the information about the server's
network interfaces (and at least Windows 8 and above do this, if not
other clients) there are some useful pieces of information you can get
including:
- all of the network interfaces that the server advertises (not just
the one you are mounting over), and with SMB3 supporting multichannel
this helps with more than just failover (also aggregating multiple
sockets under one mount)
- whether the adapter supports RSS (useful to know if you want to
estimate whether setting up two or more socket connections to the same
address is going to be faster due to RSS offload in the adapter)
- whether the server supports RDMA
- whether the server has IPv6 interfaces (if you connected over IPv4
but prefer IPv6 e.g.)
- what the link speed is (you might want to reconnect over a higher
speed interface if available)
(Of course we could also rerequest this on every mount cheaplly to the
same server, as Windows apparently does, so we can update the adapter
info on new mounts, and also on every reconnect if the network
interface drops temporarily - so we don't have to rely on info from
the first mount to this server)
It is trivial to request this information - and certainly will be useful
when we get to the point of doing multichannel (and eventually RDMA),
but some of this (linkspeed etc.) info may help for debugging in
the meantime. Enable this request when CONFIG_CIFS_STATS2 is on
(only for smb3 mounts since it is an SMB3 or later ioctl).
Signed-off-by: Steve French <smfrench@gmail.com>
In SMB3 it is now possible to query the file system
alignment info, and the preferred (for performance)
sector size and whether the underlying disk
has no seek penalty (like SSD).
Query this information at mount time for SMB3,
and make it visible in /proc/fs/cifs/DebugData
for debugging purposes.
This alignment information and preferred sector
size info will be helpful for the copy offload
patches to setup the right chunks in the CopyChunk
requests. Presumably the knowledge that the
underlying disk is SSD could also help us
make better readahead and writebehind
decisions (something to look at in the future).
Signed-off-by: Steve French <smfrench@gmail.com>
Currently SMB2 and SMB3 mounts do not query the device information at mount time
from the server as is done for cifs. These can be useful for debugging.
This is a minor patch, that extends the previous one (which added ability to
query file system attributes at mount time - this returns the device
characteristics - also via in /proc/fs/cifs/DebugData)
Signed-off-by: Steve French <smfrench@gmail.com>
Currently SMB2 and SMB3 mounts do not query the file system attributes
from the server at mount time as is done for cifs. These can be useful for debugging.
Signed-off-by: Steve French <smfrench@gmail.com>
Allow cifs/smb2/smb3 to return whether or not a file is compressed
via lsattr, and allow SMB2/SMB3 to set the per-file compression
flag ("chattr +c filename" on an smb3 mount).
Windows users often set the compressed flag (it can be
done from the desktop and file manager). David Disseldorp
has patches to Samba server to support this (at least on btrfs)
which are complementary to this
Signed-off-by: Steve French <smfrench@gmail.com>
that force a client to purge cache pages when a server requests it.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
to make adding new types of lease buffers easier.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
that prepare the code to handle different types of SMB2 leases.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
that allows to access files through symlink created on a server.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
On reconnects, we need to reopen file and then obtain all byte-range
locks held by the client. SMB2 protocol provides feature to make
this process atomic by reconnecting to the same file handle
with all it's byte-range locks. This patch adds this capability
for SMB2 shares.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steven French <steven@steven-GA-970A-DS3.(none)>
to prepare it for further durable handle reconnect processing.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steven French <steven@steven-GA-970A-DS3.(none)>
and eliminated unused file_attribute parms of SMB2_open.
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steven French <steven@steven-GA-970A-DS3.(none)>
Commit 9ddec56131 (cifs: move handling of signed connections into
separate function) broke signing on SMB2/3 connections. While the code
to enable signing on the connections was very similar between the two,
the bits that get set in the sec_mode are different.
Declare a couple of new smb_version_values fields and set them
appropriately for SMB1 and SMB2/3. Then change cifs_enable_signing to
use those instead.
Reported-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Fix build warning in Shirish's recent SMB3 signing patch
which occurs when SMB2 support is disabled in Kconfig.
fs/built-in.o: In function `cifs_setup_session':
>> (.text+0xa1767): undefined reference to `generate_smb3signingkey'
Pointed out by: automated 0-DAY kernel build testing backend
Intel Open Source Technology Center
CC: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Cut and paste likely introduced accidentally inserted spurious #define
in d60622eb5a causes no harm but looks weird
Signed-off-by: Steve French <smfrench@gmail.com>
SMB3 protocol adds various optional per-share capabilities (and
SMB3.02 adds one more beyond that). Add ability to dump
(/proc/fs/cifs/DebugData) the share capabilities and share flags to
improve debugging.
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
The new Windows update supports SMB3.02 dialect, a minor update to SMB3.
This patch adds support for mounting with vers=3.02
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
It's not obvious from reading the macro names that these macros
are for debugging. Convert the names to a single more typical
kernel style cifs_dbg macro.
cERROR(1, ...) -> cifs_dbg(VFS, ...)
cFYI(1, ...) -> cifs_dbg(FYI, ...)
cFYI(DBG2, ...) -> cifs_dbg(NOISY, ...)
Move the terminating format newline from the macro to the call site.
Add CONFIG_CIFS_DEBUG function cifs_vfs_err to emit the
"CIFS VFS: " prefix for VFS messages.
Size is reduced ~ 1% when CONFIG_CIFS_DEBUG is set (default y)
$ size fs/cifs/cifs.ko*
text data bss dec hex filename
265245 2525 132 267902 4167e fs/cifs/cifs.ko.new
268359 2525 132 271016 422a8 fs/cifs/cifs.ko.old
Other miscellaneous changes around these conversions:
o Miscellaneous typo fixes
o Add terminating \n's to almost all formats and remove them
from the macros to be more kernel style like. A few formats
previously had defective \n's
o Remove unnecessary OOM messages as kmalloc() calls dump_stack
o Coalesce formats to make grep easier,
added missing spaces when coalescing formats
o Use %s, __func__ instead of embedded function name
o Removed unnecessary "cifs: " prefixes
o Convert kzalloc with multiply to kcalloc
o Remove unused cifswarn macro
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
If we have mandatory byte-range locks on a file we can't cache reads
because pagereading may have conflicts with these locks on the server.
That's why we should allow level2 oplocks for files without mandatory
locks only.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Restructure code to make SMB2 vs. SMB3 signing a protocol
specific op. SMB3 signing (AES_CMAC) is not enabled yet,
but this restructuring at least makes sure we don't send
an smb2 signature on an smb3 signed connection. A followon
patch will add AES_CMAC and enable smb3 signing.
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Jeff Layton <jlayton@samba.org>
This patch enables optional for original SMB2 (SMB2.02) dialect
by specifying vers=2.0 on mount.
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
because the is no difference here. This also adds support of prefixpath
mount option for SMB2.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Based on whether the user (on mount command) chooses:
vers=3.0 (for smb3.0 support)
vers=2.1 (for smb2.1 support)
or (with subsequent patch, which will allow SMB2 support)
vers=2.0 (for original smb2.02 dialect support)
send only one dialect at a time during negotiate (we
had been sending a list).
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Some trivial endian fixes for the SMB2 code. One
warning remains which I asked Pavel to look at.
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
Now that we aren't abusing the kmap address space, there's no need for
this lock or to impose a limit on the rsize.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Now that we're not kmapping so much at once, there's no need to cap
the wsize at the amount that can be simultaneously kmapped.
Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Steve French