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: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
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: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@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: Steve French <stfrench@microsoft.com>
Signed-off-by: Ronnie 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: Steve French <stfrench@microsoft.com>
Signed-off-by: Ronnie 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: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie 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: Steve French <stfrench@microsoft.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: Steve French <stfrench@microsoft.com>
Since in theory a server could respond with compressed read
responses even if not requested on read request (assuming that
a compression negcontext is sent in negotiate protocol) - do
not send compression information during negotiate protocol
unless the user asks for compression explicitly (compression
is experimental), and add a mount warning that compression
is experimental.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
There is a special ACE used by some servers to allow the mode
bits to be stored. This can be especially helpful in scenarios
in which the client is trusted, and access checking on the
client vs the POSIX mode bits is sufficient.
Add mount option to allow enabling this behavior.
Follow on patch will add support for chmod and queryinfo
(stat) by retrieving the POSIX mode bits from the special
ACE, SID: S-1-5-88-3
See e.g.
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/hh509017(v=ws.10)
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
SMB3 ACL support is needed for many use cases now and should not be
ifdeffed out, even for SMB1 (CIFS). Remove the CONFIG_CIFS_ACL
ifdef so ACL support is always built into cifs.ko
Signed-off-by: Steve French <stfrench@microsoft.com>
If we mount the same share twice, we check the flags to see if the
second mount matches the earlier mount, but we left some flags out.
Signed-off-by: Steve French <stfrench@microsoft.com>
We can not depend on the tcon->open_file_lock here since in multiuser mode
we may have the same file/inode open via multiple different tcons.
The current code is race prone and will crash if one user deletes a file
at the same time a different user opens/create the file.
To avoid this we need to have a spinlock attached to the inode and not the tcon.
RHBZ: 1580165
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Add llseek op for SEEK_DATA and SEEK_HOLE.
Improves xfstests/285,286,436,445,448 and 490
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Two of the common symlink formats use reparse points
(unlike mfsymlinks and also unlike the SMB1 posix
extensions). This is the first part of the fixes
to allow these reparse points (NFS style and Windows
symlinks) to be resolved properly as symlinks by the
client.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
New negotiate context (3) allows the server and client to
negotiate which compression algorithms to use. Add support
for this and save it off in the server structure.
Also now displayed in /proc/fs/cifs/DebugData (see below example
to Windows 10) where compression algoirthm "LZ77" was negotiated:
Servers:
Number of credits: 326 Dialect 0x311 COMPRESS_LZ77 signed
1) Name: 192.168.92.17 Uses: 1 Capability: 0x300067 Session Status: 1 TCP status: 1 Instance: 1
See MS-XCA and MS-SMB2 2.2.3.1 for more details.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
The flags were named confusingly.
CIFS_ASYNC_OP now just means that we will not block waiting for credits
to become available so we thus rename this to be CIFS_NON_BLOCKING.
Change CIFS_NO_RESP to CIFS_NO_RSP_BUF to clarify that we will actually get a
response from the server but we will not get/do not want a response buffer.
Delete CIFSSMBNotify. This is an SMB1 function that is not used.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
For SMB1 oplock breaks we would grab one credit while sending the PDU
but we would never relese the credit back since we will never receive a
response to this from the server. Eventuallt this would lead to a hang
once all credits are leaked.
Fix this by defining a new flag CIFS_NO_SRV_RSP which indicates that there
is no server response to this command and thus we need to add any credits back
immediately after sending the PDU.
CC: Stable <stable@vger.kernel.org> #v5.0+
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Useful for improved copy performance as well as for
applications which query allocated ranges of sparse
files.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
if we mount A then mount A again with nodfs, we shouldn't reuse the
superblock. document the purpose of the defines as well.
there are most likely more flags that needs to be added to this mask,
in fact the logic to find them should be which flag should
be *ignored* when trying to reuse an existing sb.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
In the oplock break handler, writing pending changes from pages puts
the FileInfo handle. If the refcount reaches zero it closes the handle
and waits for any oplock break handler to return, thus causing a deadlock.
To prevent this situation:
* We add a wait flag to cifsFileInfo_put() to decide whether we should
wait for running/pending oplock break handlers
* We keep an additionnal reference of the SMB FileInfo handle so that
for the rest of the handler putting the handle won't close it.
- The ref is bumped everytime we queue the handler via the
cifs_queue_oplock_break() helper.
- The ref is decremented at the end of the handler
This bug was triggered by xfstest 464.
Also important fix to address the various reports of
oops in smb2_push_mandatory_locks
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reconnecting after server or network failure can be improved
(to maintain availability and protect data integrity) by allowing
the client to choose the default persistent (or resilient)
handle timeout in some use cases. Today we default to 0 which lets
the server pick the default timeout (usually 120 seconds) but this
can be problematic for some workloads. Add the new mount parameter
to cifs.ko for SMB3 mounts "handletimeout" which enables the user
to override the default handle timeout for persistent (mount
option "persistenthandles") or resilient handles (mount option
"resilienthandles"). Maximum allowed is 16 minutes (960000 ms).
Units for the timeout are expressed in milliseconds. See
section 2.2.14.2.12 and 2.2.31.3 of the MS-SMB2 protocol
specification for more information.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
This cleanup removes cifs specific code from SMB2/SMB3 code paths
which is cleaner and easier to maintain as the code to handle
special files is improved. Below is an example creating special files
using 'sfu' mount option over SMB3 to Windows (with this patch)
(Note that to Samba server, support for saving dos attributes
has to be enabled for the SFU mount option to work).
In the future this will also make implementation of creating
special files as reparse points easier (as Windows NFS server does
for example).
root@smf-Thinkpad-P51:~# stat -c "%F" /mnt2/char
character special file
root@smf-Thinkpad-P51:~# stat -c "%F" /mnt2/block
block special file
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
When we open the shared root handle also ask for FILE_ALL_INFORMATION since
we can do this at zero cost as part of a compound.
Cache this information as long as the lease is held and return and serve any
future requests from cache.
This allows us to serve "stat /<mountpoint>" directly from cache and avoid
a network roundtrip. Since clients often want to do this quite a lot
this improve performance slightly.
As an example: xfstest generic/533 performs 43 stat operations on the root
of the share while it is run. Which are eliminated with this patch.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Change wait_for_free_credits() to allow waiting for >=1 credits instead of just
a single credit.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Currently we adjust MTU credits before sending an IO request
and after reopening a file. This approach doesn't allow the
reopen routine to use existing credits that are not needed
for IO. Reorder credit adjustment and reopening a file to
use credits available to the client more efficiently. Also
unwrap complex if statement into few pieces to improve
readability.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Every time after a session reconnect we don't need to account for
credits obtained in previous sessions. Make use of the recently
added cifs_credits structure to properly calculate credits for
non-MTU requests the same way we did for MTU ones.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Every time after a session reconnect we don't need to account for
credits obtained in previous sessions. Introduce new struct cifs_credits
which contains both credits value and reconnect instance of the
time those credits were taken. Modify a routine that add credits
back to handle the reconnect instance by assuming zero credits
if the reconnect happened after the credits were obtained and
before we decided to add them back due to some errors during sending.
This patch fixes the MTU credits cases. The subsequent patch
will handle non-MTU ones.
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>
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>
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>
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>
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>
After failing to reconnect to original target, it will retry any
target available from DFS cache.
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This patch will make use of DFS cache routines where appropriate and
do not always request a new referral from server.
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
* Add new dfs_cache.[ch] files
* Add new /proc/fs/cifs/dfscache file
- dump current cache when read
- clear current cache when writing "0" to it
* Add delayed_work to periodically refresh cache entries
The new interface will be used for caching DFS referrals, as well as
supporting client target failover.
The DFS cache is a hashtable that maps UNC paths to cache entries.
A cache entry contains:
- the UNC path it is mapped on
- how much the the UNC path the entry consumes
- flags
- a Time-To-Live after which the entry expires
- a list of possible targets (linked lists of UNC paths)
- a "hint target" pointing the last known working target or the first
target if none were tried. This hint lets cifs.ko remember and try
working targets first.
* Looking for an entry in the cache is done with dfs_cache_find()
- if no valid entries are found, a DFS query is made, stored in the
cache and returned
- the full target list can be copied and returned to avoid race
conditions and looped on with the help with the
dfs_cache_tgt_iterator
* Updating the target hint to the next target is done with
dfs_cache_update_tgthint()
These functions have a dfs_cache_noreq_XXX() version that doesn't
fetches referrals if no entries are found. These versions don't
require the tcp/ses/tcon/cifs_sb parameters as a result.
Expired entries cannot be used and since they have a pretty short TTL
[1] in order for them to be useful for failover the DFS cache adds a
delayed work called periodically to keep them fresh.
Since we might not have available connections to issue the referral
request when refreshing we need to store volume_info structs with
credentials and other needed info to be able to connect to the right
server.
1: Windows defaults: 5mn for domain-based referrals, 30mn for regular
links
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This will be needed by DFS cache.
Signed-off-by: Paulo Alcantara <palcantara@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Technically 3.02 is not the dialect name although that is more familiar to
many, so we should also accept the official dialect name (3.0.2 vs. 3.02)
in vers=
Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
With direct I/O read, we transfer the data directly from transport layer to
the user data buffer.
Change in v3: add support for kernel AIO
Change in v4:
Refactor common read code to __cifs_readv for direct and non-direct I/O.
Retry on direct I/O failure.
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
In order to debug complex problems it is often helpful to
have detailed information on the client and server view
of the open file information. Add the ability for root to
view the list of smb3 open files and dump the persistent
handle and other info so that it can be more easily
correlated with server logs.
Sample output from "cat /proc/fs/cifs/open_files"
# Version:1
# Format:
# <tree id> <persistent fid> <flags> <count> <pid> <uid> <filename> <mid>
0x5 0x800000378 0x8000 1 7704 0 some-file 0x14
0xcb903c0c 0x84412e67 0x8000 1 7754 1001 rofile 0x1a6d
0xcb903c0c 0x9526b767 0x8000 1 7720 1000 file 0x1a5b
0xcb903c0c 0x9ce41a21 0x8000 1 7715 0 smallfile 0xd67
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
To allow better debugging (for example applications with
handle leaks, or complex reconnect scenarios) display the
number of open files (on the client) and number of open
server file handles for each tcon in /proc/fs/cifs/Stats.
Note that open files on server is one larger than local
due to handle caching (in this case of the root of
the share). In this example there are two local
open files, and three (two file and one directory handle)
open on the server.
Sample output:
$ cat /proc/fs/cifs/Stats
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: 36 maximum at one time: 2
1) \\localhost\test
SMBs: 69
Bytes read: 27 Bytes written: 0
Open files: 2 total (local), 3 open on server
TreeConnects: 1 total 0 failed
TreeDisconnects: 0 total 0 failed
Creates: 19 total 0 failed
Closes: 16 total 0 failed
...
Signed-off-by: Steve French <stfrench@microsoft.com>
We do not call cifs_open_file() for directories and thus we do not have a
pSMBFile we can extract the FIDs from.
Solve this by instead always using a compounded open/query/close for
the passthrough ioctl.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This allows userspace tools to query the raw info levels for cifs files
and process the response in userspace.
In particular this is useful for many of those data where there is no
corresponding native data structure in linux.
For example querying the security descriptor for a file and extract the
SIDs.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
RHBZ 1484130
Update cifs_find_fid_lock_conflict() to recognize that
ODF locks do not conflict with eachother.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Modern servers often support 8MB as maximum i/o size, and we see some
performance benefits (my testing showed 1 to 13% on write paths,
and 1 to 3% on read paths for increasing the default to 4MB). If server
doesn't support larger i/o size, during negotiate protocol it is already
set correctly to the server's maximum if lower than 4MB.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Each time we reconnect to the same server, bump an instance
counter (and display in /proc/fs/cifs/DebugData) to make it
easier to debug.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
/proc/fs/cifs/Stats when CONFIG_CIFS_STATS2 is enabled logs 'slow'
responses, but depending on the server you are debugging a
one second timeout may be too fast, so allow setting it to
a larger number of seconds via new module parameter
/sys/module/cifs/parameters/slow_rsp_threshold
or via modprobe:
slow_rsp_threshold:Amount of time (in seconds) to wait before
logging that a response is delayed.
Default: 1 (if set to 0 disables msg). (uint)
Recommended values are 0 (disabled) to 32767 (9 hours) with
the default remaining as 1 second.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
cifs_delete_mid() is called once we are finished handling a mid and we
expect no more work done on this mid.
Needed to fix recent commit:
commit 730928c8f4
("cifs: update smb2_queryfs() to use compounding")
Add a warning if someone tries to dequeue a mid that has already been
flagged to be deleted.
Also change list_del() to list_del_init() so that if we have similar bugs
resurface in the future we will not oops.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
