This will allow us to do protocol specific tranformations of packets
before sending to the server. For SMB3 it can be used to support
encryption.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Allocate and initialize SMB2 read request without RFC1001 length
field to directly call cifs_send_recv() rather than SendReceive2()
in a read codepath.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Do not process RFC1001 length in smb2_hdr_assemble() because
it is not a part of SMB2 header. This allows to cleanup the code
and adds a possibility combine several SMB2 packets into one
for compounding.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
In order to simplify further encryption support we need to separate
RFC1001 length and SMB2 header when sending a request. Put the length
field in iov[0] and the rest of the packet into following iovs.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Now SendReceive2 frees the first iov and returns a response buffer
in it that increases a code complexity. Simplify this by making
a caller responsible for freeing request buffer itself and returning
a response buffer in a separate iov.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
In order to support compounding and encryption we need to separate
RFC1001 length field and SMB2 header structure because the protocol
treats them differently. This change will allow to simplify parsing
of such complex SMB2 packets further.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Currently we call copy_page_to_iter() for uncached reading into a pipe.
This is wrong because it treats pages as VFS cache pages and copies references
rather than actual data. When we are trying to read from the pipe we end up
calling page_cache_pipe_buf_confirm() which returns -ENODATA. This error
is translated into 0 which is returned to a user.
This issue is reproduced by running xfs-tests suite (generic test #249)
against mount points with "cache=none". Fix it by mapping pages manually
and calling copy_to_iter() that copies data into the pipe.
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
List soft dependencies of cifs so that mkinitrd and dracut can include
the required helper modules.
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Steve French <sfrench@samba.org>
The sha256 and cmac crypto modules are only needed for SMB2+, so move
the select statements to config CIFS_SMB2. Also select CRYPTO_AES
there as SMB2+ needs it.
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Steve French <sfrench@samba.org>
* CIFS_SMB2 depends on CIFS, which depends on INET and selects NLS. So
these dependencies do not need to be repeated for CIFS_SMB2.
* CIFS_SMB311 depends on CIFS_SMB2, which depends on INET. So this
dependency doesn't need to be repeated for CIFS_SMB311.
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Steve French <sfrench@samba.org>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
CC: Stable <stable@vger.kernel.org>
file_info_lock is not initalized in initiate_cifs_search(), leading to the
following splat after a simple "mount.cifs ... dir && ls dir/":
BUG: spinlock bad magic on CPU#0, ls/486
lock: 0xffff880009301110, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
CPU: 0 PID: 486 Comm: ls Not tainted 4.9.0 #27
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
ffffc900042f3db0 ffffffff81327533 0000000000000000 ffff880009301110
ffffc900042f3dd0 ffffffff810baf75 ffff880009301110 ffffffff817ae077
ffffc900042f3df0 ffffffff810baff6 ffff880009301110 ffff880008d69900
Call Trace:
[<ffffffff81327533>] dump_stack+0x65/0x92
[<ffffffff810baf75>] spin_dump+0x85/0xe0
[<ffffffff810baff6>] spin_bug+0x26/0x30
[<ffffffff810bb159>] do_raw_spin_lock+0xe9/0x130
[<ffffffff8159ad2f>] _raw_spin_lock+0x1f/0x30
[<ffffffff8127e50d>] cifs_closedir+0x4d/0x100
[<ffffffff81181cfd>] __fput+0x5d/0x160
[<ffffffff81181e3e>] ____fput+0xe/0x10
[<ffffffff8109410e>] task_work_run+0x7e/0xa0
[<ffffffff81002512>] exit_to_usermode_loop+0x92/0xa0
[<ffffffff810026f9>] syscall_return_slowpath+0x49/0x50
[<ffffffff8159b484>] entry_SYSCALL_64_fastpath+0xa7/0xa9
Fixes: 3afca265b5 ("Clarify locking of cifs file and tcon structures and make more granular")
Signed-off-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Steve French <smfrench@gmail.com>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull cifs fixes from Steve French:
"This ncludes various cifs/smb3 bug fixes, mostly for stable as well.
In the next week I expect that Germano will have some reconnection
fixes, and also I expect to have the remaining pieces of the snapshot
enablement and SMB3 ACLs, but wanted to get this set of bug fixes in"
* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
cifs_get_root shouldn't use path with tree name
Fix default behaviour for empty domains and add domainauto option
cifs: use %16phN for formatting md5 sum
cifs: Fix smbencrypt() to stop pointing a scatterlist at the stack
CIFS: Fix a possible double locking of mutex during reconnect
CIFS: Fix a possible memory corruption during reconnect
CIFS: Fix a possible memory corruption in push locks
CIFS: Fix missing nls unload in smb2_reconnect()
CIFS: Decrease verbosity of ioctl call
SMB3: parsing for new snapshot timestamp mount parm
Pull partial readlink cleanups from Miklos Szeredi.
This is the uncontroversial part of the readlink cleanup patch-set that
simplifies the default readlink handling.
Miklos and Al are still discussing the rest of the series.
* git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
vfs: make generic_readlink() static
vfs: remove ".readlink = generic_readlink" assignments
vfs: default to generic_readlink()
vfs: replace calling i_op->readlink with vfs_readlink()
proc/self: use generic_readlink
ecryptfs: use vfs_get_link()
bad_inode: add missing i_op initializers
When a server returns the optional flag SMB_SHARE_IS_IN_DFS in response
to a tree connect, cifs_build_path_to_root() will return a pathname
which includes the hostname. This causes problems with cifs_get_root()
which separates each component and does a lookup for each component of
the path which in this case will incorrectly include looking up the
hostname component as a path component.
We encountered a problem with dfs shares hosted by a Netapp. When
connecting to nodes pointed to by the DFS share. The tree connect for
these nodes return SMB_SHARE_IS_IN_DFS resulting failures in lookup
in cifs_get_root().
RH bz: 1373153
The patch was tested against a Netapp simulator and by a user using an
actual Netapp server.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reported-by: Pierguido Lambri <plambri@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
With commit 2b149f119 many things have been fixed/introduced.
However, the default behaviour for RawNTLMSSP authentication
seems to be wrong in case the domain is not passed on the command line.
The main points (see below) of the patch are:
- It alignes behaviour with Windows clients
- It fixes backward compatibility
- It fixes UPN
I compared this behavour with the one from a Windows 10 command line
client. When no domains are specified on the command line, I traced
the packets and observed that the client does send an empty
domain to the server.
In the linux kernel case, the empty domain is replaced by the
primary domain communicated by the SMB server.
This means that, if the credentials are valid against the local server
but that server is part of a domain, then the kernel module will
ask to authenticate against that domain and we will get LOGON failure.
I compared the packet trace from the smbclient when no domain is passed
and, in that case, a default domain from the client smb.conf is taken.
Apparently, connection succeeds anyway, because when the domain passed
is not valid (in my case WORKGROUP), then the local one is tried and
authentication succeeds. I tried with any kind of invalid domain and
the result was always a connection.
So, trying to interpret what to do and picking a valid domain if none
is passed, seems the wrong thing to do.
To this end, a new option "domainauto" has been added in case the
user wants a mechanism for guessing.
Without this patch, backward compatibility also is broken.
With kernel 3.10, the default auth mechanism was NTLM.
One of our testing servers accepted NTLM and, because no
domains are passed, authentication was local.
Moving to RawNTLMSSP forced us to change our command line
to add a fake domain to pass to prevent this mechanism to kick in.
For the same reasons, UPN is broken because the domain is specified
in the username.
The SMB server will work out the domain from the UPN and authenticate
against the right server.
Without the patch, though, given the domain is empty, it gets replaced
with another domain that could be the wrong one for the authentication.
Signed-off-by: Germano Percossi <germano.percossi@citrix.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Passing a gazillion arguments takes a lot of code:
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-253 (-253)
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
smbencrypt() points a scatterlist to the stack, which is breaks if
CONFIG_VMAP_STACK=y.
Fix it by switching to crypto_cipher_encrypt_one(). The new code
should be considerably faster as an added benefit.
This code is nearly identical to some code that Eric Biggers
suggested.
Cc: stable@vger.kernel.org # 4.9 only
Reported-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Pull block layer updates from Jens Axboe:
"This is the main block pull request this series. Contrary to previous
release, I've kept the core and driver changes in the same branch. We
always ended up having dependencies between the two for obvious
reasons, so makes more sense to keep them together. That said, I'll
probably try and keep more topical branches going forward, especially
for cycles that end up being as busy as this one.
The major parts of this pull request is:
- Improved support for O_DIRECT on block devices, with a small
private implementation instead of using the pig that is
fs/direct-io.c. From Christoph.
- Request completion tracking in a scalable fashion. This is utilized
by two components in this pull, the new hybrid polling and the
writeback queue throttling code.
- Improved support for polling with O_DIRECT, adding a hybrid mode
that combines pure polling with an initial sleep. From me.
- Support for automatic throttling of writeback queues on the block
side. This uses feedback from the device completion latencies to
scale the queue on the block side up or down. From me.
- Support from SMR drives in the block layer and for SD. From Hannes
and Shaun.
- Multi-connection support for nbd. From Josef.
- Cleanup of request and bio flags, so we have a clear split between
which are bio (or rq) private, and which ones are shared. From
Christoph.
- A set of patches from Bart, that improve how we handle queue
stopping and starting in blk-mq.
- Support for WRITE_ZEROES from Chaitanya.
- Lightnvm updates from Javier/Matias.
- Supoort for FC for the nvme-over-fabrics code. From James Smart.
- A bunch of fixes from a whole slew of people, too many to name
here"
* 'for-4.10/block' of git://git.kernel.dk/linux-block: (182 commits)
blk-stat: fix a few cases of missing batch flushing
blk-flush: run the queue when inserting blk-mq flush
elevator: make the rqhash helpers exported
blk-mq: abstract out blk_mq_dispatch_rq_list() helper
blk-mq: add blk_mq_start_stopped_hw_queue()
block: improve handling of the magic discard payload
blk-wbt: don't throttle discard or write zeroes
nbd: use dev_err_ratelimited in io path
nbd: reset the setup task for NBD_CLEAR_SOCK
nvme-fabrics: Add FC LLDD loopback driver to test FC-NVME
nvme-fabrics: Add target support for FC transport
nvme-fabrics: Add host support for FC transport
nvme-fabrics: Add FC transport LLDD api definitions
nvme-fabrics: Add FC transport FC-NVME definitions
nvme-fabrics: Add FC transport error codes to nvme.h
Add type 0x28 NVME type code to scsi fc headers
nvme-fabrics: patch target code in prep for FC transport support
nvme-fabrics: set sqe.command_id in core not transports
parser: add u64 number parser
nvme-rdma: align to generic ib_event logging helper
...
If .readlink == NULL implies generic_readlink().
Generated by:
to_del="\.readlink.*=.*generic_readlink"
for i in `git grep -l $to_del`; do sed -i "/$to_del"/d $i; done
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
With the current code it is possible to lock a mutex twice when
a subsequent reconnects are triggered. On the 1st reconnect we
reconnect sessions and tcons and then persistent file handles.
If the 2nd reconnect happens during the reconnecting of persistent
file handles then the following sequence of calls is observed:
cifs_reopen_file -> SMB2_open -> small_smb2_init -> smb2_reconnect
-> cifs_reopen_persistent_file_handles -> cifs_reopen_file (again!).
So, we are trying to acquire the same cfile->fh_mutex twice which
is wrong. Fix this by moving reconnecting of persistent handles to
the delayed work (smb2_reconnect_server) and submitting this work
every time we reconnect tcon in SMB2 commands handling codepath.
This can also lead to corruption of a temporary file list in
cifs_reopen_persistent_file_handles() because we can recursively
call this function twice.
Cc: Stable <stable@vger.kernel.org> # v4.9+
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
We can not unlock/lock cifs_tcp_ses_lock while walking through ses
and tcon lists because it can corrupt list iterator pointers and
a tcon structure can be released if we don't hold an extra reference.
Fix it by moving a reconnect process to a separate delayed work
and acquiring a reference to every tcon that needs to be reconnected.
Also do not send an echo request on newly established connections.
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
If maxBuf is not 0 but less than a size of SMB2 lock structure
we can end up with a memory corruption.
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
New mount option "snapshot=<time>" to allow mounting an earlier
version of the remote volume (if such a snapshot exists on
the server).
Note that eventually specifying a snapshot time of 1 will allow
the user to mount the oldest snapshot. A subsequent patch
add the processing for that and another for actually specifying
the "time warp" create context on SMB2/SMB3 open.
Check to make sure SMB2 negotiated, and ensure that
we use a different tcon if mount same share twice
but with different snaphshot times
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Commit 2211d5ba5c ("posix_acl: xattr representation cleanups")
removes the typedefs and the zero-length a_entries array in struct
posix_acl_xattr_header, and uses bare struct posix_acl_xattr_header
and struct posix_acl_xattr_entry directly.
But it failed to iterate over posix acl slots when converting posix
acls to CIFS format, which results in several test failures in
xfstests (generic/053 generic/105) when testing against a samba v1
server, starting from v4.9-rc1 kernel. e.g.
[root@localhost xfstests]# diff -u tests/generic/105.out /root/xfstests/results//generic/105.out.bad
--- tests/generic/105.out 2016-09-19 16:33:28.577962575 +0800
+++ /root/xfstests/results//generic/105.out.bad 2016-10-22 15:41:15.201931110 +0800
@@ -1,3 +1,4 @@
QA output created by 105
-rw-r--r-- root
+setfacl: subdir: Invalid argument
-rw-r--r-- root
Fix it by introducing a new "ace" var, like what
cifs_copy_posix_acl() does, and iterating posix acl xattr entries
over it in the for loop.
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Commit 4fcd1813e6 ("Fix reconnect to not defer smb3 session reconnect
long after socket reconnect") changes the behaviour of the SMB2 echo
service and causes it to renegotiate after a socket reconnect. However
under default settings, the echo service could take up to 120 seconds to
be scheduled.
The patch forces the echo service to be called immediately resulting a
negotiate call being made immediately on reconnect.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Andy Lutromirski's new virtually mapped kernel stack allocations moves
kernel stacks the vmalloc area. This triggers the bug
kernel BUG at ./include/linux/scatterlist.h:140!
at calc_seckey()->sg_init()
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
New mount option "idsfromsid" indicates to cifs.ko that
it should try to retrieve the uid and gid owner fields
from special sids. This patch adds the code to parse the owner
sids in the ACL to see if they match, and if so populate the
uid and/or gid from them. This is faster than upcalling for
them and asking winbind, and is a fairly common case, and is
also helpful when cifs.upcall and idmapping is not configured.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Add "idsfromsid" mount option to indicate to cifs.ko that it should
try to retrieve the uid and gid owner fields from special sids in the
ACL if present. This first patch just adds the parsing for the mount
option.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
We are already doing the same thing for an ordinary open case:
we can't keep read oplock on a file if we have mandatory byte-range
locks because pagereading can conflict with these locks on a server.
Fix it by setting oplock level to NONE.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
openFileList of tcon can be changed while cifs_reopen_file() is called
that can lead to an unexpected behavior when we return to the loop.
Fix this by introducing a temp list for keeping all file handles that
need to be reopen.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
We split the rawntlmssp authentication into negotiate and
authencate parts. We also clean up the code and add helpers.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Add helper functions and split Kerberos authentication off
SMB2_sess_setup.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
/sys/module/cifs/parameters should display the three
other module load time configuration settings for cifs.ko
Signed-off-by: Germano Percossi <germano.percossi@citrix.com>
Signed-off-by: Steve French <steve.french@primarydata.com>
Cleanup some missing mem frees on some cifs ioctls, and
clarify others to make more obvious that no data is returned.
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
[CIFS] We had cases where we sent a SMB2/SMB3 setinfo request with all
timestamp (and DOS attribute) fields marked as 0 (ie do not change)
e.g. on chmod or chown.
Signed-off-by: Steve French <steve.french@primarydata.com>
CC: Stable <stable@vger.kernel.org>
Add mount option "max_credits" to allow setting maximum SMB3
credits to any value from 10 to 64000 (default is 32000).
This can be useful to workaround servers with problems allocating
credits, or to throttle the client to use smaller amount of
simultaneous i/o or to workaround server performance issues.
Also adds a cap, so that even if the server granted us more than
65000 credits due to a server bug, we would not use that many.
Signed-off-by: Steve French <steve.french@primarydata.com>
Continuous Availability features like persistent handles
require that clients reconnect their open files, not
just the sessions, soon after the network connection comes
back up, otherwise the server will throw away the state
(byte range locks, leases, deny modes) on those handles
after a timeout.
Add code to reconnect handles when use_persistent set
(e.g. Continuous Availability shares) after tree reconnect.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Germano Percossi <germano.percossi@citrix.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Remove the global file_list_lock to simplify cifs/smb3 locking and
have spinlocks that more closely match the information they are
protecting.
Add new tcon->open_file_lock and file->file_info_lock spinlocks.
Locks continue to follow a heirachy,
cifs_socket --> cifs_ses --> cifs_tcon --> cifs_file
where global tcp_ses_lock still protects socket and cifs_ses, while the
the newer locks protect the lower level structure's information
(tcon and cifs_file respectively).
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <steve.french@primarydata.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Germano Percossi <germano.percossi@citrix.com>
Patch a6b5058 results in -EREMOTE returned by is_path_accessible() in
cifs_mount() to be ignored which breaks DFS mounting.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
When we open a durable handle we give a Globally Unique
Identifier (GUID) to the server which we must keep for later reference
e.g. when reopening persistent handles on reconnection.
Without this the GUID generated for a new persistent handle was lost and
16 zero bytes were used instead on re-opening.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
GUIDs although random, and 16 bytes, need to be generated as
proper uuids.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reported-by: David Goebels <davidgoe@microsoft.com>
CC: Stable <stable@vger.kernel.org>
The kernel client requests 2 credits for many operations even though
they only use 1 credit (presumably to build up a buffer of credit).
Some servers seem to give the client as much credit as is requested. In
this case, the amount of credit the client has continues increasing to
the point where (server->credits * MAX_BUFFER_SIZE) overflows in
smb2_wait_mtu_credits().
Fix this by throttling the credit requests if an set limit is reached.
For async requests where the credit charge may be > 1, request as much
credit as what is charged.
The limit is chosen somewhat arbitrarily. The Windows client
defaults to 128 credits, the Windows server allows clients up to
512 credits (or 8192 for Windows 2016), and the NetApp server
(and at least one other) does not limit clients at all.
Choose a high enough value such that the client shouldn't limit
performance.
This behavior was seen with a NetApp filer (NetApp Release 9.0RC2).
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
In debugging smb3, it is useful to display the number
of credits available, so we can see when the server has not granted
sufficient operations for the client to make progress, or alternatively
the client has requested too many credits (as we saw in a recent bug)
so we can compare with the number of credits the server thinks
we have.
Add a /proc/fs/cifs/DebugData line to display the client view
on how many credits are available.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reported-by: Germano Percossi <germano.percossi@citrix.com>
CC: Stable <stable@vger.kernel.org>
