commit 979a2665eb upstream.
If we call fiemap on a truncated file with none blocks allocated,
it makes sense we get nothing from this call. No output means
no blocks have been counted, but the call succeeded. It's a valid
response.
Simple example reproducer:
xfs_io -f 'truncate 2M' -c 'fiemap -v' /cifssch/testfile
xfs_io: ioctl(FS_IOC_FIEMAP) ["/cifssch/testfile"]: Invalid argument
Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 86f740f2ae upstream.
To rename a file in SMB2 we open it with the DELETE access and do a
special SetInfo on it. If the handle is missing the DELETE bit the
server will fail the SetInfo with STATUS_ACCESS_DENIED.
We currently try to reuse any existing opened handle we have with
cifs_get_writable_path(). That function looks for handles with WRITE
access but doesn't check for DELETE, making rename() fail if it finds
a handle to reuse. Simple reproducer below.
To select handles with the DELETE bit, this patch adds a flag argument
to cifs_get_writable_path() and find_writable_file() and the existing
'bool fsuid_only' argument is converted to a flag.
The cifsFileInfo struct only stores the UNIX open mode but not the
original SMB access flags. Since the DELETE bit is not mapped in that
mode, this patch stores the access mask in cifs_fid on file open,
which is accessible from cifsFileInfo.
Simple reproducer:
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#define E(s) perror(s), exit(1)
int main(int argc, char *argv[])
{
int fd, ret;
if (argc != 3) {
fprintf(stderr, "Usage: %s A B\n"
"create&open A in write mode, "
"rename A to B, close A\n", argv[0]);
return 0;
}
fd = openat(AT_FDCWD, argv[1], O_WRONLY|O_CREAT|O_SYNC, 0666);
if (fd == -1) E("openat()");
ret = rename(argv[1], argv[2]);
if (ret) E("rename()");
ret = close(fd);
if (ret) E("close()");
return ret;
}
$ gcc -o bugrename bugrename.c
$ ./bugrename /mnt/a /mnt/b
rename(): Permission denied
Fixes: 8de9e86c67 ("cifs: create a helper to find a writeable handle by path name")
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 85db6b7ae6 upstream.
RHBZ: 1752437
Before we add a new EA we should check that this will not overflow
the maximum buffer we have available to read the EAs back.
Otherwise we can get into a situation where the EAs are so big that
we can not read them back to the client and thus we can not list EAs
anymore or delete them.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 731b82bb17 upstream.
Fix two places where we need to adjust down the max response size for
ioctl when it is used together with compounding.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 86a7964be7 upstream.
There is a race between a system call processing thread
and the demultiplex thread when mid->resp_buf becomes NULL
and later is being accessed to get credits. It happens when
the 1st thread wakes up before a mid callback is called in
the 2nd one but the mid state has already been set to
MID_RESPONSE_RECEIVED. This causes NULL pointer dereference
in mid callback.
Fix this by saving credits from the response before we
update the mid state and then use this value in the mid
callback rather then accessing a response buffer.
Cc: Stable <stable@vger.kernel.org>
Fixes: ee258d7915 ("CIFS: Move credit processing to mid callbacks for SMB3")
Tested-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There may be situations when a server negotiates SMB 2.1
protocol version or higher but responds to a CREATE request
with an oplock rather than a lease.
Currently the client doesn't handle such a case correctly:
when another CREATE comes in the server sends an oplock
break to the initial CREATE and the client doesn't send
an ack back due to a wrong caching level being set (READ
instead of RWH). Missing an oplock break ack makes the
server wait until the break times out which dramatically
increases the latency of the second CREATE.
Fix this by properly detecting oplocks when using SMB 2.1
protocol version and higher.
Cc: <stable@vger.kernel.org>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
We were not bumping up the "open on server" (num_remote_opens)
counter (in some cases) on opens of the share root so
could end up showing as a negative value.
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
commit a091c5f67c99 ("smb3: allow parallelizing decryption of reads")
had a potential null dereference
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
An earlier patch "CIFS: fix deadlock in cached root handling"
did not completely address the deadlock in open_shroot. This
patch addresses the deadlock.
In testing the recent patch:
smb3: improve handling of share deleted (and share recreated)
we were able to reproduce the open_shroot deadlock to one
of the target servers in unmount in a delete share scenario.
Fixes: 7e5a70ad88 ("CIFS: fix deadlock in cached root handling")
This is version 2 of this patch. An earlier version of this
patch "smb3: fix unmount hang in open_shroot" had a problem
found by Dan.
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
When a share is deleted, returning EIO is confusing and no useful
information is logged. Improve the handling of this case by
at least logging a better error for this (and also mapping the error
differently to EREMCHG). See e.g. the new messages that would be logged:
[55243.639530] server share \\192.168.1.219\scratch deleted
[55243.642568] CIFS VFS: \\192.168.1.219\scratch BAD_NETWORK_NAME: \\192.168.1.219\scratch
In addition for the case where a share is deleted and then recreated
with the same name, have now fixed that so it works. This is sometimes
done for example, because the admin had to move a share to a different,
bigger local drive when a share is running low on space.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
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>
No point in offloading read decryption if no other requests on the
wire
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.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>
Where we have a tcon available we can log \\server\share as part
of the message. Only do this for the VFS log level.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
In smb3_punch_hole, variable cifsi set but not used, remove it.
In cifs_lock, variable netfid set but not used, remove it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Add support to send smb2 set-info commands from userspace.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <palcantara@suse.de>
Fix kernel oops when mounting a encryptData CIFS share with
CONFIG_DEBUG_VIRTUAL
Signed-off-by: Sebastien Tisserant <stisserant@wallix.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
When a reconnect happens in the middle of processing a compound chain
the code leaks a buffer from the memory pool. Fix this by properly
checking for a return code and freeing buffers in case of error.
Also maintain a buf variable to be equal to either smallbuf or bigbuf
depending on a response buffer size while parsing a chain and when
returning to the caller.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We can cut one third of the traffic on open by not querying the
inode number explicitly via SMB3 query_info since it is now
returned on open in the qfid context.
This is better in multiple ways, and
speeds up file open about 10% (more if network is slow).
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Prevent deadlock between open_shroot() and
cifs_mark_open_files_invalid() by releasing the lock before entering
SMB2_open, taking it again after and checking if we still need to use
the result.
Link: https://lore.kernel.org/linux-cifs/684ed01c-cbca-2716-bc28-b0a59a0f8521@prodrive-technologies.com/T/#u
Fixes: 3d4ef9a153 ("smb3: fix redundant opens on root")
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
RHBZ: 1722704
In low memory situations the various SMB2_*_init() functions can fail
to allocate a request PDU and thus leave the request iovector as NULL.
If we don't check the return code for failure we end up calling
smb2_set_next_command() with a NULL iovector causing a crash when it tries
to dereference it.
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
RHBZ: 1672539
In smb2_query_symlink(), if we are parsing the error buffer but it is not something
we recognize as a symlink we should return -EINVAL and not -ENOENT.
I.e. the entry does exist, it is just not something we recognize.
Additionally, add check to verify that that the errortag and the reparsetag all make sense.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Will be helpful as we improve handling of special file types.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The 'NFS' style symlinks (see MS-FSCC 2.1.2.4) were not
being queried properly in query_symlink. Fix this.
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>
SMB3.1.1 GCM performs much better than the older CCM default:
more than twice as fast in the write patch (copy to the Samba
server on localhost for example) and 80% faster on the read
patch (copy from the server).
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
GCM is faster. Request it during negotiate protocol.
Followon patch will add callouts to GCM crypto
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
We never parsed/returned any data from .get_link() when the object is a windows reparse-point
containing a symlink. This results in the VFS layer oopsing accessing an uninitialized buffer:
...
[ 171.407172] Call Trace:
[ 171.408039] readlink_copy+0x29/0x70
[ 171.408872] vfs_readlink+0xc1/0x1f0
[ 171.409709] ? readlink_copy+0x70/0x70
[ 171.410565] ? simple_attr_release+0x30/0x30
[ 171.411446] ? getname_flags+0x105/0x2a0
[ 171.412231] do_readlinkat+0x1b7/0x1e0
[ 171.412938] ? __ia32_compat_sys_newfstat+0x30/0x30
...
Fix this by adding code to handle these buffers and make sure we do return a valid buffer
to .get_link()
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Based on 1 normalized pattern(s):
this library is free software you can redistribute it and or modify
it under the terms of the gnu general public license v2 as published
by the free software foundation this library is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu lesser general public license for more details
you should have received a copy of the gnu lesser general public
license along with this library if not write to the free software
foundation inc 59 temple place suite 330 boston ma 02111 1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 2 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.539286961@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Minor cleanup - e.g. missing \n at end of debug statement.
Reported-by: Christoph Probst <kernel@probst.it>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Fix checkpatch warnings/errors in smb2ops.c except "LONG_LINE". Add missing
linebreaks, indentings, __func__. Remove void-returns, unneeded braces.
Address warnings spotted by checkpatch.
Add SPDX License Header.
Add missing "\n" and capitalize first letter in some cifs_dbg() strings.
Signed-off-by: Christoph Probst <kernel@probst.it>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Pavel Shilovsky <pshilov@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>
Change strcat to strncpy in the "None" case to fix a buffer overflow
when cinode->oplock is reset to 0 by another thread accessing the same
cinode. It is never valid to append "None" to any other message.
Consolidate multiple writes to cinode->oplock to reduce raciness.
Signed-off-by: Christoph Probst <kernel@probst.it>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
For zero-range that also extend the file we were sending this as a
compound of two different operations; a fsctl to set-zero-data for the range
and then an additional set-info to extend the file size.
This does not work for Azure since it does not support this fsctl which leads
to fallocate(FALLOC_FL_ZERO_RANGE) failing but still changing the file size.
To fix this we un-compound this and send these two operations as separate
commands, firsat one command to set-zero-data for the range and it this
was successful we proceed to send a set-info to update the file size.
This fixes xfstest generic/469 for Azure servers.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Remove the conditional to fail zero-range if the file is not flagged as sparse.
You can still zero out a range in SMB2 even for non-sparse files.
Tested with stock windows16 server.
Fixes 5 xfstests (033, 149, 155, 180, 349)
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.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>
SMB2 Ioctl responses from servers may respond with both the request blob from
the client followed by the actual reply blob for ioctls that are bi-directional.
In that case we can not assume that the reply blob comes immediately after the
ioctl response structure.
This fixes FSCTLs such as SMB2:FSCTL_QUERY_ALLOCATED_RANGES
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
DesiredAccess field in SMB3 open request needs
to be set differently for READ vs. WRITE ioctls
(not just ones that request both).
Originally noticed by Pavel
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Add support to pass a blob to the server in FSCTL passthrough.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
If we enter smb2_query_symlink() for something that is not a symlink
and where the SMB2_open() would succeed we would never end up
closing this handle and would thus leak a handle on the server.
Fix this by immediately calling SMB2_close() on successfull open.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
It only means that we do not have a valid cached value for the
file_all_info structure.
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>
Some servers (see MS-SMB2 protocol specification
section 3.3.5.15.1) expect that the FSCTL enumerate snapshots
is done twice, with the first query having EXACTLY the minimum
size response buffer requested (16 bytes) which refreshes
the snapshot list (otherwise that and subsequent queries get
an empty list returned). So had to add code to set
the maximum response size differently for the first snapshot
query (which gets the size needed for the second query which
contains the actual list of snapshots).
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> # 4.19+
Fix a bug where we used to not initialize the cached fid structure at all
in open_shroot() if the open was successful but we did not get a lease.
This would leave the structure uninitialized and later when we close the handle
we would in close_shroot() try to kref_put() an uninitialized refcount.
Fix this by always initializing this structure if the open was successful
but only do the extra get() if we got a lease.
This extra get() is only used to hold the structure until we get a lease
break from the server at which point we will kref_put() it during lease
processing.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
For debugging purposes we often have to be able to query
additional information only available via SMB3 FSCTL
from the server from user space tools (e.g. like
cifs-utils's smbinfo). See MS-FSCC and MS-SMB2 protocol
specifications for more details.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
smb2_set_sparse does not return -errno, it returns a boolean where
true means success.
Change this to just ignore the return value just like the other callsites.
Additionally add code to handle the case where we must set the file sparse
and possibly also extending it.
Fixes xfstests: generic/236 generic/350 generic/420
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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>
Murphy Zhou