Currently we set reconnect instance to zero on the first
connection but this is not convenient because we need to
reserve some special value for credit handling on reconnects
which is coming in subsequent patches. Fix this by starting
with one when initiating a new TCP connection.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
There are a couple places where we still account for 4 bytes
in the beginning of SMB2 packet which is not true in the current
code. Fix this to use a header preamble size where possible.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Even if a response is malformed, we should count credits
granted by the server to avoid miscalculations and unnecessary
reconnects due to client or server bugs. If the response has
been received partially, the session will be reconnected anyway
on the next iteration of the demultiplex thread, so counting
credits for such cases shouldn't break things.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently we only skip credits logging on reconnects. When
unmounting a share the number of credits on the client doesn't
matter, so skip logging in such cases too.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently we skip setting a read error to -EIO if a stored
result is -ENODATA and a response hasn't been received. With
the recent changes in read error processing there shouldn't be
cases when -ENODATA is set without a response from the server,
so reset the error to -EIO unconditionally.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When we hit failures during constructing MIDs or sending PDUs
through the network, we end up not using message IDs assigned
to the packet. The next SMB packet will skip those message IDs
and continue with the next one. This behavior may lead to a server
not granting us credits until we use the skipped IDs. Fix this by
reverting the current ID to the original value if any errors occur
before we push the packet through the network stack.
This patch fixes the generic/310 test from the xfs-tests.
Cc: <stable@vger.kernel.org> # 4.19.x
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
If we try large I/O (read or write) immediately after mount
we won't typically have enough credits because we only request
large amounts of credits on the first session setup. So if
large I/O is attempted soon after mount we will typically only
have about 43 credits rather than 105 credits (with this patch)
available for the large i/o (which needs 64 credits minimum).
This patch requests more credits during tree connect, which
helps ensure that we have enough credits when mount completes
(between these requests and the first session setup) in order
to start large I/O immediately after mount if needed.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
We negotiate rsize mounts (and it can be overridden by user) to
typically 4MB, so using larger default I/O sizes from userspace
(changing to 1MB default i/o size returned by stat) the
performance is much better (and not just for long latency
network connections) in most use cases for SMB3 than the default I/O
size (which ends up being 128K for cp and can be even smaller for cp).
This can be 4x slower or worse depending on network latency.
By changing inode->blocksize from 32K (which was perhaps ok
for very old SMB1/CIFS) to a larger value, 1MB (but still less than
max size negotiated with the server which is 4MB, in order to minimize
risk) it significantly increases performance for the
noncached case, and slightly increases it for the cached case.
This can be changed by the user on mount (specifying bsize=
values from 16K to 16MB) to tune better for performance
for applications that depend on blocksize.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Currently on lease break the client sets a caching level twice:
when oplock is detected and when oplock is processed. While the
1st attempt sets the level to the value provided by the server,
the 2nd one resets the level to None unconditionally.
This happens because the oplock/lease processing code was changed
to avoid races between page cache flushes and oplock breaks.
The commit c11f1df500 ("cifs: Wait for writebacks to complete
before attempting write.") fixed the races for oplocks but didn't
apply the same changes for leases resulting in overwriting the
server granted value to None. Fix this by properly processing
lease breaks.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
/proc/fs/cifs/Stats bytes_read was double counting reads when
uncached (ie mounted with cache=none)
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
BUGZILLA: https://bugzilla.kernel.org/show_bug.cgi?id=202007
When deleting an xattr/EA:
SMB2/3 servers will return SUCCESS when clients delete non-existing EAs.
This means that we need to first QUERY the server and check if the EA
exists or not so that we can return -ENODATA correctly when this happens.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We should add any credits granted to us from unmatched server responses.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
a trivial patch that replaces all use of snprintf with scnprintf.
scnprintf() is generally seen as a safer function to use than
snprintf for many use cases.
In our case, there is no actual difference between the two since we never
look at the return value. Thus we did not have any of the bugs that
scnprintf protects against and the patch does nothing.
However, for people reading our code it will be a receipt that we
have done our due dilligence and checked our code for this type of bugs.
See the presentation "Making C Less Dangerous In The Linux Kernel"
at this years LCA
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
There is a NULL pointer dereference of devname in strspn()
The oops looks something like:
CIFS: Attempting to mount (null)
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
...
RIP: 0010:strspn+0x0/0x50
...
Call Trace:
? cifs_parse_mount_options+0x222/0x1710 [cifs]
? cifs_get_volume_info+0x2f/0x80 [cifs]
cifs_setup_volume_info+0x20/0x190 [cifs]
cifs_get_volume_info+0x50/0x80 [cifs]
cifs_smb3_do_mount+0x59/0x630 [cifs]
? ida_alloc_range+0x34b/0x3d0
cifs_do_mount+0x11/0x20 [cifs]
mount_fs+0x52/0x170
vfs_kern_mount+0x6b/0x170
do_mount+0x216/0xdc0
ksys_mount+0x83/0xd0
__x64_sys_mount+0x25/0x30
do_syscall_64+0x65/0x220
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Fix this by adding a NULL check on devname in cifs_parse_devname()
Signed-off-by: Yao Liu <yotta.liu@ucloud.cn>
Signed-off-by: Steve French <stfrench@microsoft.com>
If we don't find a writable file handle when retrying writepages
we break of the loop and do not unlock and put pages neither from
wdata2 nor from the original wdata. Fix this by walking through
all the remaining pages and cleanup them properly.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The request buffers are freed right before copying the pointers.
Use the func args instead which are identical and still valid.
Simple reproducer (requires KASAN enabled) on a cifs mount:
echo foo > foo ; tail -f foo & rm foo
Cc: <stable@vger.kernel.org> # 4.20
Fixes: 179e44d49c ("smb3: add tracepoint for sending lease break responses to server")
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
When doing reads beyound the end of a file the server returns
error STATUS_END_OF_FILE error which is mapped to -ENODATA.
Currently we report it as a failure which confuses read stats.
Change it to not consider -ENODATA as failure for stat purposes.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Currently we log success once we send an async IO request to
the server. Instead we need to analyse a response and then log
success or failure for a particular command. Also fix argument
list for read logging.
Cc: <stable@vger.kernel.org> # 4.18
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Allocation of a page array for non-cached IO was separated from
allocation of rdata and wdata structures and this introduced memory
leaks and a possible null pointer dereference. This patch fixes
these problems.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
minus the various headers and blobs that will be part of the reply.
or else we might trigger a session reconnect.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
The size of the fixed part of the create response is 88 bytes not 56.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Was helpful in debug for some recent problems.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Otherwise we gradually leak credits leading to potential
hung session.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
If the server doesn't grant us at least 3 credits during the mount
we won't be able to complete it because query path info operation
requires 3 credits. Use the cached file handle if possible to allow
the mount to succeed.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
If we don't receive a response we can't assume that the server
granted one credit. Assume zero credits in such cases.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The current code doesn't do proper accounting for credits
in SMB1 case: it adds one credit per response only if we get
a complete response while it needs to return it unconditionally.
Fix this and also include malformed responses for SMB2+ into
accounting for credits because such responses have Credit
Granted field, thus nothing prevents to get a proper credit
value from them.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We do need to account for credits received in error responses
to read requests on encrypted sessions.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently we mark MID as malformed if we get an error from server
in a read response. This leads to not properly processing credits
in the readv callback. Fix this by marking such a response as
normal received response and process it appropriately.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When executing add_credits() we currently call cifs_reconnect()
if the number of credits is zero and there are no requests in
flight. In this case we may call cifs_reconnect() recursively
twice and cause memory corruption given the following sequence
of functions:
mid1.callback() -> add_credits() -> cifs_reconnect() ->
-> mid2.callback() -> add_credits() -> cifs_reconnect().
Fix this by avoiding to call cifs_reconnect() in add_credits()
and checking for zero credits in the demultiplex thread.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Precise and non-ambiguous license information is important. The recently
added aegis header file has a SPDX license identifier, which is nice, but
at the same time it has a contradictionary license boiler plate text.
SPDX-License-Identifier: GPL-2.0
versus
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
Oh well.
Assuming that the SPDX identifier is correct and according to x86/hyper-v
contributions from Microsoft GPL V2 only is the usual license.
Remove the boiler plate as it is wrong and even if correct it is redundant.
Fixes: eccb4422cf ("smb3: Add ftrace tracepoints for improved SMB3 debugging")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
When doing MTU i/o we need to leave some credits for
possible reopen requests and other operations happening
in parallel. Currently we leave 1 credit which is not
enough even for reopen only: we need at least 2 credits
if durable handle reconnect fails. Also there may be
other operations at the same time including compounding
ones which require 3 credits at a time each. Fix this
by leaving 8 credits which is big enough to cover most
scenarios.
Was able to reproduce this when server was configured
to give out fewer credits than usual.
The proper fix would be to reconnect a file handle first
and then obtain credits for an MTU request but this leads
to bigger code changes and should happen in other patches.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The call to SMB2_queary_acl can allocate memory to pntsd and also
return a failure via a call to SMB2_query_acl (and then query_info).
This occurs when query_info allocates the structure and then in
query_info the call to smb2_validate_and_copy_iov fails. Currently the
failure just returns without kfree'ing pntsd hence causing a memory
leak.
Currently, *data is allocated if it's not already pointing to a buffer,
so it needs to be kfree'd only if was allocated in query_info, so the
fix adds an allocated flag to track this. Also set *dlen to zero on
an error just to be safe since *data is kfree'd.
Also set errno to -ENOMEM if the allocation of *data fails.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Dan Carpener <dan.carpenter@oracle.com>
This patch aims to address writeback code problems related to error
paths. In particular it respects EINTR and related error codes and
stores and returns the first error occurred during writeback.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently we account for credits in the thread initiating a request
and waiting for a response. The demultiplex thread receives the response,
wakes up the thread and the latter collects credits from the response
buffer and add them to the server structure on the client. This approach
is not accurate, because it may race with reconnect events in the
demultiplex thread which resets the number of credits.
Fix this by moving credit processing to new mid callbacks that collect
credits granted by the server from the response in the demultiplex thread.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
If a request is cancelled, we can't assume that the server returns
1 credit back. Instead we need to wait for a response and process
the number of credits granted by the server.
Create a separate mid callback for cancelled request, parse the number
of credits in a response buffer and add them to the client's credits.
If the didn't get a response (no response buffer available) assume
0 credits granted. The latter most probably happens together with
session reconnect, so the client's credits are adjusted anyway.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
If maxBuf is small but non-zero, it could result in a zero sized lock
element array which we would then try and access OOB.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
The code tries to allocate a contiguous buffer with a size supplied by
the server (maxBuf). This could fail if memory is fragmented since it
results in high order allocations for commonly used server
implementations. It is also wasteful since there are probably
few locks in the usual case. Limit the buffer to be no larger than a
page to avoid memory allocation failures due to fragmentation.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This addresses some compile warnings that you can
see depending on configuration settings.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently we hide EINTR code returned from sock_sendmsg()
and return 0 instead. This makes a caller think that we
successfully completed the network operation which is not
true. Fix this by properly returning EINTR to callers.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
In SMB3 protocol every part of the compound chain consumes credits
individually, so we need to call wait_for_free_credits() for each
of the PDUs in the chain. If an operation is interrupted, we must
ensure we return all credits taken from the server structure back.
Without this patch server can sometimes disconnect the session
due to credit mismatches, especially when first operation(s)
are large writes.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Currently we reset the number of total credits granted by the server
to 1 if the server didn't grant us anything int the response. This
violates the SMB3 protocol - we need to trust the server and use
the credit values from the response. Fix this by removing the
corresponding code.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Currently for MTU requests we allocate maximum possible credits
in advance and then adjust them according to the request size.
While we were adjusting the number of credits belonging to the
server, we were skipping adjustment of credits belonging to the
request. This patch fixes it by setting request credits to
CreditCharge field value of SMB2 packet header.
Also ask 1 credit more for async read and write operations to
increase parallelism and match the behavior of other operations.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
The most recent "it" allocation is leaked on this error path. I
believe that small allocations always succeed in current kernels so
this doesn't really affect run time.
Fixes: 54be1f6c1c ("cifs: Add DFS cache routines")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This debug message was never shown because it was checking for NULL
returns but extract_hostname() returns error pointers.
Fixes: 93d5cb517d ("cifs: Add support for failover in cifs_reconnect()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
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Merge tag '4.21-smb3-small-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull smb3 fixes from Steve French:
"Three fixes, one for stable, one adds the (most secure) SMB3.1.1
dialect to default list requested"
* tag '4.21-smb3-small-fixes' of git://git.samba.org/sfrench/cifs-2.6:
smb3: add smb3.1.1 to default dialect list
cifs: fix confusing warning message on reconnect
smb3: fix large reads on encrypted connections
Multiple filesystems open code lru_to_page(). Rectify this by moving
the macro from mm_inline (which is specific to lru stuff) to the more
generic mm.h header and start using the macro where appropriate.
No functional changes.
Link: http://lkml.kernel.org/r/20181129104810.23361-1-nborisov@suse.com
Link: https://lkml.kernel.org/r/20181129075301.29087-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Pankaj gupta <pagupta@redhat.com>
Acked-by: "Yan, Zheng" <zyan@redhat.com> [ceph]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Shilovsky
Namjae Jeon
Pavel Shilovsky
Steve French
Ronnie Sahlberg
Yao Liu
Aurelien Aptel
Thomas Gleixner
Colin Ian King
Ross Lagerwall
Dan Carpenter
Linus Torvalds
Nikolay Borisov