In the current implementation, CIFS close sends a close to the
server and does not check for the success of the server close.
This patch adds functionality to check for server close return
status and retries in case of an EBUSY or EAGAIN error.
This can help avoid handle leaks
Cc: stable@vger.kernel.org
Signed-off-by: Ritvik Budhiraja <rbudhiraja@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Some code paths for querying server interfaces make a false
assumption that it will only get called for SMB3+. Since this
function now can get called from a generic code paths, the correct
thing to do is to have specific handler for this functionality
per SMB dialect, and call this handler.
This change adds such a handler and implements this handler only
for SMB 3.0 and 3.1.1.
Cc: stable@vger.kernel.org
Cc: Jan Čermák <sairon@sairon.cz>
Reported-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Change "compress=" mount option to a boolean flag, that, if set,
will enable negotiating compression algorithms with the server.
Do not de/compress anything for now.
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Add support for creating special files via WSL reparse points when
using 'reparse=wsl' mount option. They're faster than NFS reparse
points because they don't require extra roundtrips to figure out what
->d_type a specific dirent is as such information is already stored in
query dir responses and then making getdents() calls faster.
Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
There are cases where a session is disconnected and password has changed
on the server (or expired) for this user and this currently can not
be fixed without unmount and mounting again. This patch allows
remount to change the password (for the non Kerberos case, Kerberos
ticket refresh is handled differently) when the session is disconnected
and the user can not reconnect due to still using old password.
Future patches should also allow us to setup the keyring (cifscreds)
to have an "alternate password" so we would be able to change
the password before the session drops (without the risk of races
between when the password changes and the disconnect occurs -
ie cases where the old password is still needed because the new
password has not fully rolled out to all servers yet).
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
File open requests made to the server contain a
CreateGuid, which is used by the server to identify
the open request. If the same request needs to be
replayed, it needs to be sent with the same CreateGuid
in the durable handle v2 context.
Without doing so, we could end up leaking handles on
the server when:
1. multichannel is used AND
2. connection goes down, but not for all channels
This is because the replayed open request would have a
new CreateGuid and the server will treat this as a new
request and open a new handle.
This change fixes this by reusing the existing create_guid
stored in the cached fid struct.
REF: MS-SMB2 4.9 Replay Create Request on an Alternate Channel
Fixes: 4f1fffa237 ("cifs: commands that are retried should have replay flag set")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Send query dir requests with an info level of
SMB_FIND_FILE_FULL_DIRECTORY_INFO rather than
SMB_FIND_FILE_DIRECTORY_INFO when the client is generating its own
inode numbers (e.g. noserverino) so that reparse tags still
can be parsed directly from the responses, but server won't
send UniqueId (server inode number)
Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
In order to scale down the channels, the following sequence
of operations happen:
1. server struct is marked for terminate
2. the channel is deallocated in the ses->chans array
3. at a later point the cifsd thread actually terminates the server
Between 2 and 3, there can be calls to find the channel for
a server struct. When that happens, there can be an ugly warning
that's logged. But this is expected.
So this change does two things:
1. in cifs_ses_get_chan_index, if server->terminate is set, return
2. always make sure server->terminate is set with chan_lock held
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When the server reports query network interface info call
as unsupported following a tree connect, it means that
multichannel is unsupported, even if the server capabilities
report otherwise.
When this happens, cifs_chan_skip_or_disable is called to
disable multichannel on the client. However, we only need
to call this when multichannel is currently setup.
Fixes: f591062bdb ("cifs: handle servers that still advertise multichannel after disabling")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Following a successful cifs_tree_connect, we have the code
to scale up/down the number of channels in the session.
However, it is not protected by a lock today.
As a result, this code can be executed by several processes
that select the same channel. The core functions handle this
well, as they pick chan_lock. However, we've seen cases where
smb2_reconnect throws some warnings.
To fix that, this change introduces a flags bitmap inside the
cifs_ses structure. A new flag type is used to ensure that
only one process enters this section at any time.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
A recent change moved the code that decides to skip
a channel or disable multichannel entirely, into a
helper function.
During this, a mutex_unlock of the session_mutex
should have been removed. Doing that here.
Fixes: f591062bdb ("cifs: handle servers that still advertise multichannel after disabling")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Similar to the rest of the commands, this is a change
to add replay flags on retry. This one does not add a
back-off, considering that we may want to flush a write
ASAP to the server. Considering that this will be a
flush of cached pages, the retrans value is also not
honoured.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
MS-SMB2 states that the header flag SMB2_FLAGS_REPLAY_OPERATION
needs to be set when a command needs to be retried, so that
the server is aware that this is a replay for an operation that
appeared before.
This can be very important, for example, for state changing
operations and opens which get retried following a reconnect;
since the client maybe unaware of the status of the previous
open.
This is particularly important for multichannel scenario, since
disconnection of one connection does not mean that the session
is lost. The requests can be replayed on another channel.
This change also makes use of exponential back-off before replays
and also limits the number of retries to "retrans" mount option
value.
Also, this change does not modify the read/write codepath.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Some servers like Azure SMB servers always advertise multichannel
capability in server capabilities list. Such servers return error
STATUS_NOT_IMPLEMENTED for ioctl calls to query server interfaces,
and expect clients to consider that as a sign that they do not support
multichannel.
We already handled this at mount time. Soon after the tree connect,
we query server interfaces. And when server returned STATUS_NOT_IMPLEMENTED,
we kept interface list as empty. When cifs_try_adding_channels gets
called, it would not find any interfaces, so will not add channels.
For the case where an active multichannel mount exists, and multichannel
is disabled by such a server, this change will now allow the client
to disable secondary channels on the mount. It will check the return
status of query server interfaces call soon after a tree reconnect.
If the return status is EOPNOTSUPP, then instead of the check to add
more channels, we'll disable the secondary channels instead.
For better code reuse, this change also moves the common code for
disabling multichannel to a helper function.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Today, we schedule periodic query for server interfaces
once every 10 minutes once a tree connection has been
established. Recent change to handle disabling of
multichannel disabled this delayed work.
This change reenables it following a reconnect, and
the server advertises multichannel.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The data offset for the SMB3.1.1 POSIX create context will always be
8-byte aligned so having the check 'noff + nlen >= doff' in
smb2_parse_contexts() is wrong as it will lead to -EINVAL because noff
+ nlen == doff.
Fix the sanity check to correctly handle aligned create context data.
Fixes: af1689a9b7 ("smb: client: fix potential OOBs in smb2_parse_contexts()")
Signed-off-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Today, the tree connect and disconnect requests are
sent on the primary channel only. However, the new
multichannel logic allows the session to remain active
even if one of the channels are alive. So a tree connect
can now be triggered during a reconnect on any of
its channels.
This change changes tcon and tdis calls to pick an
active channel instead of the first one.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The variable tcon_exist is being assigned however it is never read, the
variable is redundant and can be removed.
Cleans up clang scan build warning:
warning: Although the value stored to 'tcon_exist' is used in
the enclosing expression, the value is never actually readfrom
'tcon_exist' [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Change SMB2_set_eof() to take eof as CPU order rather than __le64 and pass
it directly rather than by pointer. This moves the conversion down into
SMB_set_eof() rather than all of its callers and means we don't need to
undo it for the traceline.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Reconnect worker currently assumes that the server struct
is alive and only takes reference on the server if it needs
to call smb2_reconnect.
With the new ability to disable channels based on whether the
server has multichannel disabled, this becomes a problem when
we need to disable established channels. While disabling the
channels and deallocating the server, there could be reconnect
work that could not be cancelled (because it started).
This change forces the reconnect worker to unconditionally
take a reference on the server when it runs.
Also, this change now allows smb2_reconnect to know if it was
called by the reconnect worker. Based on this, the cifs_put_tcp_session
can decide whether it can cancel the reconnect work synchronously or not.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This reverts commit 19a4b9d6c3.
This earlier commit was making an assumption that each mod_delayed_work
called for the reconnect work would result in smb2_reconnect_server
being called twice. This assumption turns out to be untrue. So reverting
this change for now.
I will submit a follow-up patch to fix the actual problem in a different
way.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When compiling with gcc version 14.0.0 20231126 (experimental)
and CONFIG_FORTIFY_SOURCE=y, I've noticed the following:
In file included from ./include/linux/string.h:295,
from ./include/linux/bitmap.h:12,
from ./include/linux/cpumask.h:12,
from ./arch/x86/include/asm/paravirt.h:17,
from ./arch/x86/include/asm/cpuid.h:62,
from ./arch/x86/include/asm/processor.h:19,
from ./arch/x86/include/asm/cpufeature.h:5,
from ./arch/x86/include/asm/thread_info.h:53,
from ./include/linux/thread_info.h:60,
from ./arch/x86/include/asm/preempt.h:9,
from ./include/linux/preempt.h:79,
from ./include/linux/spinlock.h:56,
from ./include/linux/wait.h:9,
from ./include/linux/wait_bit.h:8,
from ./include/linux/fs.h:6,
from fs/smb/client/smb2pdu.c:18:
In function 'fortify_memcpy_chk',
inlined from '__SMB2_close' at fs/smb/client/smb2pdu.c:3480:4:
./include/linux/fortify-string.h:588:25: warning: call to '__read_overflow2_field'
declared with attribute warning: detected read beyond size of field (2nd parameter);
maybe use struct_group()? [-Wattribute-warning]
588 | __read_overflow2_field(q_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
and:
In file included from ./include/linux/string.h:295,
from ./include/linux/bitmap.h:12,
from ./include/linux/cpumask.h:12,
from ./arch/x86/include/asm/paravirt.h:17,
from ./arch/x86/include/asm/cpuid.h:62,
from ./arch/x86/include/asm/processor.h:19,
from ./arch/x86/include/asm/cpufeature.h:5,
from ./arch/x86/include/asm/thread_info.h:53,
from ./include/linux/thread_info.h:60,
from ./arch/x86/include/asm/preempt.h:9,
from ./include/linux/preempt.h:79,
from ./include/linux/spinlock.h:56,
from ./include/linux/wait.h:9,
from ./include/linux/wait_bit.h:8,
from ./include/linux/fs.h:6,
from fs/smb/client/cifssmb.c:17:
In function 'fortify_memcpy_chk',
inlined from 'CIFS_open' at fs/smb/client/cifssmb.c:1248:3:
./include/linux/fortify-string.h:588:25: warning: call to '__read_overflow2_field'
declared with attribute warning: detected read beyond size of field (2nd parameter);
maybe use struct_group()? [-Wattribute-warning]
588 | __read_overflow2_field(q_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In both cases, the fortification logic inteprets calls to 'memcpy()' as an
attempts to copy an amount of data which exceeds the size of the specified
field (i.e. more than 8 bytes from __le64 value) and thus issues an overread
warning. Both of these warnings may be silenced by using the convenient
'struct_group()' quirk.
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
When a server stops supporting multichannel, we will
keep attempting reconnects to the secondary channels today.
Avoid this by freeing extra channels when negotiate
returns no multichannel support.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When the user mounts with multichannel option, but the
server does not support it, there can be a time in future
where it can be supported.
With this change, such a case is handled.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
The delayed work for reconnect takes server struct
as a parameter. But it does so without holding a ref
to it. Normally, this may not show a problem as
the reconnect work is only cancelled on umount.
However, since we now plan to support scaling down of
channels, and the scale down can happen from reconnect
work itself, we need to fix it.
This change takes a reference on the server struct
before it is passed to the delayed work. And drops
the reference in the delayed work itself. Or if
the delayed work is successfully cancelled, by the
process that cancels it.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The message said it was an invalid mode, when it was intentionally
not set. Fix confusing message logged to dmesg.
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
disabled
When no directory lease support, or for IPC shares where directories
can not be opened, do not start an unneeded laundromat thread for
that mount (it wastes resources).
Fixes: d14de8067e ("cifs: Add a laundromat thread for cached directories")
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Minor cleanup pointed out by checkpatch (repeated words, missing blank
lines) in smb2pdu.c and old header location referred to in transport.c
Signed-off-by: Steve French <stfrench@microsoft.com>
Smatch warning pointed out by Dan Carpenter:
fs/smb/client/smb2pdu.c:105 smb2_hdr_assemble()
warn: variable dereferenced before check 'server' (see line 95)
Fixes: 09ee7a3bf8 ("[SMB3] send channel sequence number in SMB3 requests after reconnects")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Now we've got the common code, use it for the client as well.
Note there's a change here where we're using the server version of
UniStrcat now which had different types (__le16 vs wchar_t) but
it's not interpreting the value other than checking for 0, however
we do need casts to keep sparse happy.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Since older dialects such as CIFS do not support multichannel
the macro CIFS_SERVER_IS_CHAN can be confusing (it requires SMB 3
or later) so shorten its name to "SERVER_IS_CHAN"
Suggested-by: Tom Talpey <tom@talpey.com>
Acked-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The ChannelSequence field in the SMB3 header is supposed to be
increased after reconnect to allow the server to distinguish
requests from before and after the reconnect. We had always
been setting it to zero. There are cases where incrementing
ChannelSequence on requests after network reconnects can reduce
the chance of data corruptions.
See MS-SMB2 3.2.4.1 and 3.2.7.1
Signed-off-by: Steve French <stfrench@microsoft.com>
Cc: stable@vger.kernel.org # 5.16+
We need to specify charset, like "iocharset=utf-8", in mount options for
Chinese path if the nls_default don't support it, such as iso8859-1, the
default value for CONFIG_NLS_DEFAULT.
But now in reconnection the nls_default is used, instead of the one we
specified and used in mount, and this can lead to mount failure.
Signed-off-by: Winston Wen <wentao@uniontech.com>
Reviewed-by: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Don't collect exiting session in smb2_reconnect_server(), because it
will be released soon.
Note that the exiting session will stay in server->smb_ses_list until
it complete the cifs_free_ipc() and logoff() and then delete itself
from the list.
Signed-off-by: Winston Wen <wentao@uniontech.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The current implementation of max_credits on the client does
not work because the CreditRequest logic for several commands
does not take max_credits into account.
Still, we can end up asking the server for more credits, depending
on the number of credits in flight. For this, we need to
limit the credits while parsing the responses too.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
If plen is null when passed in, we only checked for null
in one of the two places where it could be used. Although
plen is always valid (not null) for current callers of the
SMB2_change_notify function, this change makes it more consistent.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/all/202305251831.3V1gbbFs-lkp@intel.com/
Signed-off-by: Steve French <stfrench@microsoft.com>
Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko
and helper modules) to new fs/smb subdirectory:
fs/cifs --> fs/smb/client
fs/ksmbd --> fs/smb/server
fs/smbfs_common --> fs/smb/common
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
