Commit Graph

532 Commits

Author SHA1 Message Date
Boris Protopopov 3970acf7dd SMB3: Add support for getting and setting SACLs
Add SYSTEM_SECURITY access flag and use with smb2 when opening
files for getting/setting SACLs. Add "system.cifs_ntsd_full"
extended attribute to allow user-space access to the functionality.
Avoid multiple server calls when setting owner, DACL, and SACL.

Signed-off-by: Boris Protopopov <pboris@amazon.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-18 13:25:57 -06:00
Samuel Cabrero 121d947d4f cifs: Handle witness client move notification
This message is sent to tell a client to close its current connection
and connect to the specified address.

Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14 09:18:55 -06:00
Samuel Cabrero 0ac4e2919a cifs: add witness mount option and data structs
Add 'witness' mount option to register for witness notifications.

Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-14 09:16:22 -06:00
Ronnie Sahlberg 3fa1c6d1b8 cifs: rename smb_vol as smb3_fs_context and move it to fs_context.h
Harmonize and change all such variables to 'ctx', where possible.
No changes to actual logic.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-12-13 19:12:07 -06:00
Steve French 2e4564b31b smb3: add support for stat of WSL reparse points for special file types
This is needed so when mounting to Windows we do not
misinterpret various special files created by Linux (WSL) as symlinks.
An earlier patch addressed readdir.  This patch fixes stat (getattr).

With this patch:
  File: /mnt1/char
  Size: 0          Blocks: 0          IO Block: 16384  character special file
Device: 34h/52d Inode: 844424930132069  Links: 1     Device type: 0,0
Access: (0755/crwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2020-10-21 17:46:51.839458900 -0500
Modify: 2020-10-21 17:46:51.839458900 -0500
Change: 2020-10-21 18:30:39.797358800 -0500
 Birth: -
  File: /mnt1/fifo
  Size: 0          Blocks: 0          IO Block: 16384  fifo
Device: 34h/52d Inode: 1125899906842722  Links: 1
Access: (0755/prwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2020-10-21 16:21:37.259249700 -0500
Modify: 2020-10-21 16:21:37.259249700 -0500
Change: 2020-10-21 18:30:39.797358800 -0500
 Birth: -
  File: /mnt1/block
  Size: 0          Blocks: 0          IO Block: 16384  block special file
Device: 34h/52d Inode: 844424930132068  Links: 1     Device type: 0,0
Access: (0755/brwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2020-10-21 17:10:47.913103200 -0500
Modify: 2020-10-21 17:10:47.913103200 -0500
Change: 2020-10-21 18:30:39.796725500 -0500
 Birth: -

without the patch all show up incorrectly as symlinks with annoying "operation not supported error also returned"
  File: /mnt1/charstat: cannot read symbolic link '/mnt1/char': Operation not supported

  Size: 0          Blocks: 0          IO Block: 16384  symbolic link
Device: 34h/52d Inode: 844424930132069  Links: 1
Access: (0000/l---------)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2020-10-21 17:46:51.839458900 -0500
Modify: 2020-10-21 17:46:51.839458900 -0500
Change: 2020-10-21 18:30:39.797358800 -0500
 Birth: -
  File: /mnt1/fifostat: cannot read symbolic link '/mnt1/fifo': Operation not supported

  Size: 0          Blocks: 0          IO Block: 16384  symbolic link
Device: 34h/52d Inode: 1125899906842722  Links: 1
Access: (0000/l---------)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2020-10-21 16:21:37.259249700 -0500
Modify: 2020-10-21 16:21:37.259249700 -0500
Change: 2020-10-21 18:30:39.797358800 -0500
 Birth: -
  File: /mnt1/blockstat: cannot read symbolic link '/mnt1/block': Operation not supported

  Size: 0          Blocks: 0          IO Block: 16384  symbolic link
Device: 34h/52d Inode: 844424930132068  Links: 1
Access: (0000/l---------)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2020-10-21 17:10:47.913103200 -0500
Modify: 2020-10-21 17:10:47.913103200 -0500
Change: 2020-10-21 18:30:39.796725500 -0500

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-10-23 15:38:10 -05:00
Ronnie Sahlberg 555782aa55 cifs: move smb version mount options into fs_context.c
This and related patches which move mount related
code to fs_context.c has the advantage of
shriking the code in fs/cifs/connect.c (which had
the second most lines of code of any of the files
in cifs.ko and was getting harder to read due
to its size) and will also make it easier to
switch over to the new mount API in the future.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-22 12:17:31 -05:00
Steve French 29e2792304 smb3.1.1: add new module load parm enable_gcm_256
Add new module load parameter enable_gcm_256. If set, then add
AES-256-GCM (strongest encryption type) to the list of encryption
types requested. Put it in the list as the second choice (since
AES-128-GCM is faster and much more broadly supported by
SMB3 servers).  To make this stronger encryption type, GCM-256,
required (the first and only choice, you would use module parameter
"require_gcm_256."

Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-15 23:58:15 -05:00
Steve French fbfd0b46af smb3.1.1: add new module load parm require_gcm_256
Add new module load parameter require_gcm_256. If set, then only
request AES-256-GCM (strongest encryption type).

Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-15 23:58:15 -05:00
Rohith Surabattula 8e670f77c4 Handle STATUS_IO_TIMEOUT gracefully
Currently STATUS_IO_TIMEOUT is not treated as retriable error.
It is currently mapped to ETIMEDOUT and returned to userspace
for most system calls. STATUS_IO_TIMEOUT is returned by server
in case of unavailability or throttling errors.

This patch will map the STATUS_IO_TIMEOUT to EAGAIN, so that it
can be retried. Also, added a check to drop the connection to
not overload the server in case of ongoing unavailability.

Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-10-15 23:58:04 -05:00
Paulo Alcantara e183785f25 cifs: fix check of tcon dfs in smb1
For SMB1, the DFS flag should be checked against tcon->Flags rather
than tcon->share_flags.  While at it, add an is_tcon_dfs() helper to
check for DFS capability in a more generic way.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com>
2020-08-28 12:27:33 -05:00
Linus Torvalds 327a8d76b1 16 cifs/smb3 fixes, about half DFS related, 2 fixes for stable
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Merge tag '5.9-rc-smb3-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs updates from Steve French:
 "16 cifs/smb3 fixes, about half DFS related, two fixes for stable.

  Still working on and testing an additional set of fixes (including
  updates to mount, and some fallocate scenario improvements) for later
  in the merge window"

* tag '5.9-rc-smb3-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: document and cleanup dfs mount
  cifs: only update prefix path of DFS links in cifs_tree_connect()
  cifs: fix double free error on share and prefix
  cifs: handle RESP_GET_DFS_REFERRAL.PathConsumed in reconnect
  cifs: handle empty list of targets in cifs_reconnect()
  cifs: rename reconn_inval_dfs_target()
  cifs: reduce number of referral requests in DFS link lookups
  cifs: merge __{cifs,smb2}_reconnect[_tcon]() into cifs_tree_connect()
  cifs: convert to use be32_add_cpu()
  cifs: delete duplicated words in header files
  cifs: Remove the superfluous break
  cifs: smb1: Try failing back to SetFileInfo if SetPathInfo fails
  cifs`: handle ERRBaduid for SMB1
  cifs: remove unused variable 'server'
  smb3: warn on confusing error scenario with sec=krb5
  cifs: Fix leak when handling lease break for cached root fid
2020-08-06 19:21:04 -07:00
Randy Dunlap a03f507de5 cifs: delete duplicated words in header files
Drop repeated words in multiple comments.
(be, use, the, See)

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-08-02 18:00:26 -05:00
Alexander A. Klimov cba22b1c59 Replace HTTP links with HTTPS ones: CIFS
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
          If both the HTTP and HTTPS versions
          return 200 OK and serve the same content:
            Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Link: https://lore.kernel.org/r/20200627103125.71828-1-grandmaster@al2klimov.de
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-05 14:23:38 -06:00
Kenneth D'souza 0b0430c6a1 cifs: Add get_security_type_str function to return sec type.
This code is more organized and robust.

Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
Signed-off-by: Roberto Bergantinos Corpas <rbergant@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-08 23:57:21 -05:00
Aurelien Aptel 8eec79540d cifs: multichannel: use pointer for binding channel
Add a cifs_chan pointer in struct cifs_ses that points to the channel
currently being bound if ses->binding is true.

Previously it was always the channel past the established count.

This will make reconnecting (and rebinding) a channel easier later on.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-04 13:50:55 -05:00
Aurelien Aptel 352d96f3ac cifs: multichannel: move channel selection above transport layer
Move the channel (TCP_Server_Info*) selection from the tranport
layer to higher in the call stack so that:

- credit handling is done with the server that will actually be used
  to send.
  * ->wait_mtu_credit
  * ->set_credits / set_credits
  * ->add_credits / add_credits
  * add_credits_and_wake_if

- potential reconnection (smb2_reconnect) done when initializing a
  request is checked and done with the server that will actually be
  used to send.

To do this:

- remove the cifs_pick_channel() call out of compound_send_recv()

- select channel and pass it down by adding a cifs_pick_channel(ses)
  call in:
  - smb311_posix_mkdir
  - SMB2_open
  - SMB2_ioctl
  - __SMB2_close
  - query_info
  - SMB2_change_notify
  - SMB2_flush
  - smb2_async_readv  (if none provided in context param)
  - SMB2_read         (if none provided in context param)
  - smb2_async_writev (if none provided in context param)
  - SMB2_write        (if none provided in context param)
  - SMB2_query_directory
  - send_set_info
  - SMB2_oplock_break
  - SMB311_posix_qfs_info
  - SMB2_QFS_info
  - SMB2_QFS_attr
  - smb2_lockv
  - SMB2_lease_break
    - smb2_compound_op
  - smb2_set_ea
  - smb2_ioctl_query_info
  - smb2_query_dir_first
  - smb2_query_info_comound
  - smb2_query_symlink
  - cifs_writepages
  - cifs_write_from_iter
  - cifs_send_async_read
  - cifs_read
  - cifs_readpages

- add TCP_Server_Info *server param argument to:
  - cifs_send_recv
  - compound_send_recv
  - SMB2_open_init
  - SMB2_query_info_init
  - SMB2_set_info_init
  - SMB2_close_init
  - SMB2_ioctl_init
  - smb2_iotcl_req_init
  - SMB2_query_directory_init
  - SMB2_notify_init
  - SMB2_flush_init
  - build_qfs_info_req
  - smb2_hdr_assemble
  - smb2_reconnect
  - fill_small_buf
  - smb2_plain_req_init
  - __smb2_plain_req_init

The read/write codepath is different than the rest as it is using
pages, io iterators and async calls. To deal with those we add a
server pointer in the cifs_writedata/cifs_readdata/cifs_io_parms
context struct and set it in:

- cifs_writepages      (wdata)
- cifs_write_from_iter (wdata)
- cifs_readpages       (rdata)
- cifs_send_async_read (rdata)

The [rw]data->server pointer is eventually copied to
cifs_io_parms->server to pass it down to SMB2_read/SMB2_write.
If SMB2_read/SMB2_write is called from a different place that doesn't
set the server field it will pick a channel.

Some places do not pick a channel and just use ses->server or
cifs_ses_server(ses). All cifs_ses_server(ses) calls are in codepaths
involving negprot/sess.setup.

- SMB2_negotiate         (binding channel)
- SMB2_sess_alloc_buffer (binding channel)
- SMB2_echo              (uses provided one)
- SMB2_logoff            (uses master)
- SMB2_tdis              (uses master)

(list not exhaustive)

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-06-04 13:50:55 -05:00
Steve French 82e9367c43 smb3: Add new parm "nodelete"
In order to handle workloads where it is important to make sure that
a buggy app did not delete content on the drive, the new mount option
"nodelete" allows standard permission checks on the server to work,
but prevents on the client any attempts to unlink a file or delete
a directory on that mount point.  This can be helpful when running
a little understood app on a network mount that contains important
content that should not be deleted.

Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-06-01 00:10:18 -05:00
Steve French d92c7ce41e cifs: minor update to comments around the cifs_tcp_ses_lock mutex
Update comment to note that it protects server->dstaddr

Signed-off-by: Steve French <stfrench@microsoft.com>
2020-04-21 23:51:18 -05:00
Steve French 4e8aea30f7 smb3: enable swap on SMB3 mounts
Add experimental support for allowing a swap file to be on an SMB3
mount.  There are use cases where swapping over a secure network
filesystem is preferable. In some cases there are no local
block devices large enough, and network block devices can be
hard to setup and secure.  And in some cases there are no
local block devices at all (e.g. with the recent addition of
remote boot over SMB3 mounts).

There are various enhancements that can be added later e.g.:
- doing a mandatory byte range lock over the swapfile (until
the Linux VFS is modified to notify the file system that an open
is for a swapfile, when the file can be opened "DENY_ALL" to prevent
others from opening it).
- pinning more buffers in the underlying transport to minimize memory
allocations in the TCP stack under the fs
- documenting how to create ACLs (on the server) to secure the
swapfile (or adding additional tools to cifs-utils to make it easier)

Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2020-04-10 13:32:32 -05:00
Long Li eda1c54f14 cifs: Allocate crypto structures on the fly for calculating signatures of incoming packets
CIFS uses pre-allocated crypto structures to calculate signatures for both
incoming and outgoing packets. In this way it doesn't need to allocate crypto
structures for every packet, but it requires a lock to prevent concurrent
access to crypto structures.

Remove the lock by allocating crypto structures on the fly for
incoming packets. At the same time, we can still use pre-allocated crypto
structures for outgoing packets, as they are already protected by transport
lock srv_mutex.

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-04-07 12:41:16 -05:00
Aurelien Aptel 86f740f2ae cifs: fix rename() by ensuring source handle opened with DELETE bit
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>
2020-02-24 14:20:38 -06:00
Steve French d26c2ddd33 cifs: add SMB3 change notification support
A commonly used SMB3 feature is change notification, allowing an
app to be notified about changes to a directory. The SMB3
Notify request blocks until the server detects a change to that
directory or its contents that matches the completion flags
that were passed in and the "watch_tree" flag (which indicates
whether subdirectories under this directory should be also
included).  See MS-SMB2 2.2.35 for additional detail.

To use this simply pass in the following structure to ioctl:

 struct __attribute__((__packed__)) smb3_notify {
        uint32_t completion_filter;
        bool    watch_tree;
 } __packed;

 using CIFS_IOC_NOTIFY  0x4005cf09
 or equivalently _IOW(CIFS_IOCTL_MAGIC, 9, struct smb3_notify)

SMB3 change notification is supported by all major servers.
The ioctl will block until the server detects a change to that
directory or its subdirectories (if watch_tree is set).

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-02-06 09:14:28 -06:00
Amir Goldstein 0f060936e4 SMB3: Backup intent flag missing from some more ops
When "backup intent" is requested on the mount (e.g. backupuid or
backupgid mount options), the corresponding flag was missing from
some of the operations.

Change all operations to use the macro cifs_create_options() to
set the backup intent flag if needed.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2020-02-03 16:12:47 -06:00
Vincent Whitchurch f1f27ad745 CIFS: Fix task struct use-after-free on reconnect
The task which created the MID may be gone by the time cifsd attempts to
call the callbacks on MIDs from cifs_reconnect().

This leads to a use-after-free of the task struct in cifs_wake_up_task:

 ==================================================================
 BUG: KASAN: use-after-free in __lock_acquire+0x31a0/0x3270
 Read of size 8 at addr ffff8880103e3a68 by task cifsd/630

 CPU: 0 PID: 630 Comm: cifsd Not tainted 5.5.0-rc6+ #119
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
 Call Trace:
  dump_stack+0x8e/0xcb
  print_address_description.constprop.5+0x1d3/0x3c0
  ? __lock_acquire+0x31a0/0x3270
  __kasan_report+0x152/0x1aa
  ? __lock_acquire+0x31a0/0x3270
  ? __lock_acquire+0x31a0/0x3270
  kasan_report+0xe/0x20
  __lock_acquire+0x31a0/0x3270
  ? __wake_up_common+0x1dc/0x630
  ? _raw_spin_unlock_irqrestore+0x4c/0x60
  ? mark_held_locks+0xf0/0xf0
  ? _raw_spin_unlock_irqrestore+0x39/0x60
  ? __wake_up_common_lock+0xd5/0x130
  ? __wake_up_common+0x630/0x630
  lock_acquire+0x13f/0x330
  ? try_to_wake_up+0xa3/0x19e0
  _raw_spin_lock_irqsave+0x38/0x50
  ? try_to_wake_up+0xa3/0x19e0
  try_to_wake_up+0xa3/0x19e0
  ? cifs_compound_callback+0x178/0x210
  ? set_cpus_allowed_ptr+0x10/0x10
  cifs_reconnect+0xa1c/0x15d0
  ? generic_ip_connect+0x1860/0x1860
  ? rwlock_bug.part.0+0x90/0x90
  cifs_readv_from_socket+0x479/0x690
  cifs_read_from_socket+0x9d/0xe0
  ? cifs_readv_from_socket+0x690/0x690
  ? mempool_resize+0x690/0x690
  ? rwlock_bug.part.0+0x90/0x90
  ? memset+0x1f/0x40
  ? allocate_buffers+0xff/0x340
  cifs_demultiplex_thread+0x388/0x2a50
  ? cifs_handle_standard+0x610/0x610
  ? rcu_read_lock_held_common+0x120/0x120
  ? mark_lock+0x11b/0xc00
  ? __lock_acquire+0x14ed/0x3270
  ? __kthread_parkme+0x78/0x100
  ? lockdep_hardirqs_on+0x3e8/0x560
  ? lock_downgrade+0x6a0/0x6a0
  ? lockdep_hardirqs_on+0x3e8/0x560
  ? _raw_spin_unlock_irqrestore+0x39/0x60
  ? cifs_handle_standard+0x610/0x610
  kthread+0x2bb/0x3a0
  ? kthread_create_worker_on_cpu+0xc0/0xc0
  ret_from_fork+0x3a/0x50

 Allocated by task 649:
  save_stack+0x19/0x70
  __kasan_kmalloc.constprop.5+0xa6/0xf0
  kmem_cache_alloc+0x107/0x320
  copy_process+0x17bc/0x5370
  _do_fork+0x103/0xbf0
  __x64_sys_clone+0x168/0x1e0
  do_syscall_64+0x9b/0xec0
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 Freed by task 0:
  save_stack+0x19/0x70
  __kasan_slab_free+0x11d/0x160
  kmem_cache_free+0xb5/0x3d0
  rcu_core+0x52f/0x1230
  __do_softirq+0x24d/0x962

 The buggy address belongs to the object at ffff8880103e32c0
  which belongs to the cache task_struct of size 6016
 The buggy address is located 1960 bytes inside of
  6016-byte region [ffff8880103e32c0, ffff8880103e4a40)
 The buggy address belongs to the page:
 page:ffffea000040f800 refcount:1 mapcount:0 mapping:ffff8880108da5c0
 index:0xffff8880103e4c00 compound_mapcount: 0
 raw: 4000000000010200 ffffea00001f2208 ffffea00001e3408 ffff8880108da5c0
 raw: ffff8880103e4c00 0000000000050003 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff8880103e3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8880103e3980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 >ffff8880103e3a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                           ^
  ffff8880103e3a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8880103e3b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ==================================================================

This can be reliably reproduced by adding the below delay to
cifs_reconnect(), running find(1) on the mount, restarting the samba
server while find is running, and killing find during the delay:

  	spin_unlock(&GlobalMid_Lock);
  	mutex_unlock(&server->srv_mutex);

 +	msleep(10000);
 +
  	cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
  	list_for_each_safe(tmp, tmp2, &retry_list) {
  		mid_entry = list_entry(tmp, struct mid_q_entry, qhead);

Fix this by holding a reference to the task struct until the MID is
freed.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2020-01-26 19:24:17 -06:00
Paulo Alcantara (SUSE) 046aca3c25 cifs: Optimize readdir on reparse points
When listing a directory with thounsands of files and most of them are
reparse points, we simply marked all those dentries for revalidation
and then sending additional (compounded) create/getinfo/close requests
for each of them.

Instead, upon receiving a response from an SMB2_QUERY_DIRECTORY
(FileIdFullDirectoryInformation) command, the directory entries that
have a file attribute of FILE_ATTRIBUTE_REPARSE_POINT will contain an
EaSize field with a reparse tag in it, so we parse it and mark the
dentry for revalidation only if it is a DFS or a symlink.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-12-23 09:04:44 -06:00
Pavel Shilovsky d919131935 CIFS: Close cached root handle only if it has a lease
SMB2_tdis() checks if a root handle is valid in order to decide
whether it needs to close the handle or not. However if another
thread has reference for the handle, it may end up with putting
the reference twice. The extra reference that we want to put
during the tree disconnect is the reference that has a directory
lease. So, track the fact that we have a directory lease and
close the handle only in that case.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-12-13 00:49:57 -06:00
Paulo Alcantara (SUSE) 3345bb44ba cifs: Fix lookup of SMB connections on multichannel
With the addition of SMB session channels, we introduced new TCP
server pointers that have no sessions or tcons associated with them.

In this case, when we started looking for TCP connections, we might
end up picking session channel rather than the master connection,
hence failing to get either a session or a tcon.

In order to fix that, this patch introduces a new "is_channel" field
to TCP_Server_Info structure so we can skip session channels during
lookup of connections.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-12-04 11:50:32 -06:00
Steve French 43f8a6a74e smb3: query attributes on file close
Since timestamps on files on most servers can be updated at
close, and since timestamps on our dentries default to one
second we can have stale timestamps in some common cases
(e.g. open, write, close, stat, wait one second, stat - will
show different mtime for the first and second stat).

The SMB2/SMB3 protocol allows querying timestamps at close
so add the code to request timestamp and attr information
(which is cheap for the server to provide) to be returned
when a file is closed (it is not needed for the many
paths that call SMB2_close that are from compounded
query infos and close nor is it needed for some of
the cases where a directory close immediately follows a
directory open.

Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-12-03 15:48:02 -06:00
Steve French 1ae9a5a551 smb3: dump in_send and num_waiters stats counters by default
Number of requests in_send and the number of waiters on sendRecv
are useful counters in various cases, move them from
CONFIG_CIFS_STATS2 to be on by default especially with multichannel

Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-11-25 01:17:12 -06:00
Pavel Shilovsky 9bd4540836 CIFS: Properly process SMB3 lease breaks
Currenly we doesn't assume that a server may break a lease
from RWH to RW which causes us setting a wrong lease state
on a file and thus mistakenly flushing data and byte-range
locks and purging cached data on the client. This leads to
performance degradation because subsequent IOs go directly
to the server.

Fix this by propagating new lease state and epoch values
to the oplock break handler through cifsFileInfo structure
and removing the use of cifsInodeInfo flags for that. It
allows to avoid some races of several lease/oplock breaks
using those flags in parallel.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:17:12 -06:00
Ronnie Sahlberg 32546a9586 cifs: move cifsFileInfo_put logic into a work-queue
This patch moves the final part of the cifsFileInfo_put() logic where we
need a write lock on lock_sem to be processed in a separate thread that
holds no other locks.
This is to prevent deadlocks like the one below:

> there are 6 processes looping to while trying to down_write
> cinode->lock_sem, 5 of them from _cifsFileInfo_put, and one from
> cifs_new_fileinfo
>
> and there are 5 other processes which are blocked, several of them
> waiting on either PG_writeback or PG_locked (which are both set), all
> for the same page of the file
>
> 2 inode_lock() (inode->i_rwsem) for the file
> 1 wait_on_page_writeback() for the page
> 1 down_read(inode->i_rwsem) for the inode of the directory
> 1 inode_lock()(inode->i_rwsem) for the inode of the directory
> 1 __lock_page
>
>
> so processes are blocked waiting on:
>   page flags PG_locked and PG_writeback for one specific page
>   inode->i_rwsem for the directory
>   inode->i_rwsem for the file
>   cifsInodeInflock_sem
>
>
>
> here are the more gory details (let me know if I need to provide
> anything more/better):
>
> [0 00:48:22.765] [UN]  PID: 8863   TASK: ffff8c691547c5c0  CPU: 3
> COMMAND: "reopen_file"
>  #0 [ffff9965007e3ba8] __schedule at ffffffff9b6e6095
>  #1 [ffff9965007e3c38] schedule at ffffffff9b6e64df
>  #2 [ffff9965007e3c48] rwsem_down_write_slowpath at ffffffff9af283d7
>  #3 [ffff9965007e3cb8] legitimize_path at ffffffff9b0f975d
>  #4 [ffff9965007e3d08] path_openat at ffffffff9b0fe55d
>  #5 [ffff9965007e3dd8] do_filp_open at ffffffff9b100a33
>  #6 [ffff9965007e3ee0] do_sys_open at ffffffff9b0eb2d6
>  #7 [ffff9965007e3f38] do_syscall_64 at ffffffff9ae04315
> * (I think legitimize_path is bogus)
>
> in path_openat
>         } else {
>                 const char *s = path_init(nd, flags);
>                 while (!(error = link_path_walk(s, nd)) &&
>                         (error = do_last(nd, file, op)) > 0) {  <<<<
>
> do_last:
>         if (open_flag & O_CREAT)
>                 inode_lock(dir->d_inode);  <<<<
>         else
> so it's trying to take inode->i_rwsem for the directory
>
>      DENTRY           INODE           SUPERBLK     TYPE PATH
> ffff8c68bb8e79c0 ffff8c691158ef20 ffff8c6915bf9000 DIR  /mnt/vm1_smb/
> inode.i_rwsem is ffff8c691158efc0
>
> <struct rw_semaphore 0xffff8c691158efc0>:
>         owner: <struct task_struct 0xffff8c6914275d00> (UN -   8856 -
> reopen_file), counter: 0x0000000000000003
>         waitlist: 2
>         0xffff9965007e3c90     8863   reopen_file      UN 0  1:29:22.926
>   RWSEM_WAITING_FOR_WRITE
>         0xffff996500393e00     9802   ls               UN 0  1:17:26.700
>   RWSEM_WAITING_FOR_READ
>
>
> the owner of the inode.i_rwsem of the directory is:
>
> [0 00:00:00.109] [UN]  PID: 8856   TASK: ffff8c6914275d00  CPU: 3
> COMMAND: "reopen_file"
>  #0 [ffff99650065b828] __schedule at ffffffff9b6e6095
>  #1 [ffff99650065b8b8] schedule at ffffffff9b6e64df
>  #2 [ffff99650065b8c8] schedule_timeout at ffffffff9b6e9f89
>  #3 [ffff99650065b940] msleep at ffffffff9af573a9
>  #4 [ffff99650065b948] _cifsFileInfo_put.cold.63 at ffffffffc0a42dd6 [cifs]
>  #5 [ffff99650065ba38] cifs_writepage_locked at ffffffffc0a0b8f3 [cifs]
>  #6 [ffff99650065bab0] cifs_launder_page at ffffffffc0a0bb72 [cifs]
>  #7 [ffff99650065bb30] invalidate_inode_pages2_range at ffffffff9b04d4bd
>  #8 [ffff99650065bcb8] cifs_invalidate_mapping at ffffffffc0a11339 [cifs]
>  #9 [ffff99650065bcd0] cifs_revalidate_mapping at ffffffffc0a1139a [cifs]
> #10 [ffff99650065bcf0] cifs_d_revalidate at ffffffffc0a014f6 [cifs]
> #11 [ffff99650065bd08] path_openat at ffffffff9b0fe7f7
> #12 [ffff99650065bdd8] do_filp_open at ffffffff9b100a33
> #13 [ffff99650065bee0] do_sys_open at ffffffff9b0eb2d6
> #14 [ffff99650065bf38] do_syscall_64 at ffffffff9ae04315
>
> cifs_launder_page is for page 0xffffd1e2c07d2480
>
> crash> page.index,mapping,flags 0xffffd1e2c07d2480
>       index = 0x8
>       mapping = 0xffff8c68f3cd0db0
>   flags = 0xfffffc0008095
>
>   PAGE-FLAG       BIT  VALUE
>   PG_locked         0  0000001
>   PG_uptodate       2  0000004
>   PG_lru            4  0000010
>   PG_waiters        7  0000080
>   PG_writeback     15  0008000
>
>
> inode is ffff8c68f3cd0c40
> inode.i_rwsem is ffff8c68f3cd0ce0
>      DENTRY           INODE           SUPERBLK     TYPE PATH
> ffff8c68a1f1b480 ffff8c68f3cd0c40 ffff8c6915bf9000 REG
> /mnt/vm1_smb/testfile.8853
>
>
> this process holds the inode->i_rwsem for the parent directory, is
> laundering a page attached to the inode of the file it's opening, and in
> _cifsFileInfo_put is trying to down_write the cifsInodeInflock_sem
> for the file itself.
>
>
> <struct rw_semaphore 0xffff8c68f3cd0ce0>:
>         owner: <struct task_struct 0xffff8c6914272e80> (UN -   8854 -
> reopen_file), counter: 0x0000000000000003
>         waitlist: 1
>         0xffff9965005dfd80     8855   reopen_file      UN 0  1:29:22.912
>   RWSEM_WAITING_FOR_WRITE
>
> this is the inode.i_rwsem for the file
>
> the owner:
>
> [0 00:48:22.739] [UN]  PID: 8854   TASK: ffff8c6914272e80  CPU: 2
> COMMAND: "reopen_file"
>  #0 [ffff99650054fb38] __schedule at ffffffff9b6e6095
>  #1 [ffff99650054fbc8] schedule at ffffffff9b6e64df
>  #2 [ffff99650054fbd8] io_schedule at ffffffff9b6e68e2
>  #3 [ffff99650054fbe8] __lock_page at ffffffff9b03c56f
>  #4 [ffff99650054fc80] pagecache_get_page at ffffffff9b03dcdf
>  #5 [ffff99650054fcc0] grab_cache_page_write_begin at ffffffff9b03ef4c
>  #6 [ffff99650054fcd0] cifs_write_begin at ffffffffc0a064ec [cifs]
>  #7 [ffff99650054fd30] generic_perform_write at ffffffff9b03bba4
>  #8 [ffff99650054fda8] __generic_file_write_iter at ffffffff9b04060a
>  #9 [ffff99650054fdf0] cifs_strict_writev.cold.70 at ffffffffc0a4469b [cifs]
> #10 [ffff99650054fe48] new_sync_write at ffffffff9b0ec1dd
> #11 [ffff99650054fed0] vfs_write at ffffffff9b0eed35
> #12 [ffff99650054ff00] ksys_write at ffffffff9b0eefd9
> #13 [ffff99650054ff38] do_syscall_64 at ffffffff9ae04315
>
> the process holds the inode->i_rwsem for the file to which it's writing,
> and is trying to __lock_page for the same page as in the other processes
>
>
> the other tasks:
> [0 00:00:00.028] [UN]  PID: 8859   TASK: ffff8c6915479740  CPU: 2
> COMMAND: "reopen_file"
>  #0 [ffff9965007b39d8] __schedule at ffffffff9b6e6095
>  #1 [ffff9965007b3a68] schedule at ffffffff9b6e64df
>  #2 [ffff9965007b3a78] schedule_timeout at ffffffff9b6e9f89
>  #3 [ffff9965007b3af0] msleep at ffffffff9af573a9
>  #4 [ffff9965007b3af8] cifs_new_fileinfo.cold.61 at ffffffffc0a42a07 [cifs]
>  #5 [ffff9965007b3b78] cifs_open at ffffffffc0a0709d [cifs]
>  #6 [ffff9965007b3cd8] do_dentry_open at ffffffff9b0e9b7a
>  #7 [ffff9965007b3d08] path_openat at ffffffff9b0fe34f
>  #8 [ffff9965007b3dd8] do_filp_open at ffffffff9b100a33
>  #9 [ffff9965007b3ee0] do_sys_open at ffffffff9b0eb2d6
> #10 [ffff9965007b3f38] do_syscall_64 at ffffffff9ae04315
>
> this is opening the file, and is trying to down_write cinode->lock_sem
>
>
> [0 00:00:00.041] [UN]  PID: 8860   TASK: ffff8c691547ae80  CPU: 2
> COMMAND: "reopen_file"
> [0 00:00:00.057] [UN]  PID: 8861   TASK: ffff8c6915478000  CPU: 3
> COMMAND: "reopen_file"
> [0 00:00:00.059] [UN]  PID: 8858   TASK: ffff8c6914271740  CPU: 2
> COMMAND: "reopen_file"
> [0 00:00:00.109] [UN]  PID: 8862   TASK: ffff8c691547dd00  CPU: 6
> COMMAND: "reopen_file"
>  #0 [ffff9965007c3c78] __schedule at ffffffff9b6e6095
>  #1 [ffff9965007c3d08] schedule at ffffffff9b6e64df
>  #2 [ffff9965007c3d18] schedule_timeout at ffffffff9b6e9f89
>  #3 [ffff9965007c3d90] msleep at ffffffff9af573a9
>  #4 [ffff9965007c3d98] _cifsFileInfo_put.cold.63 at ffffffffc0a42dd6 [cifs]
>  #5 [ffff9965007c3e88] cifs_close at ffffffffc0a07aaf [cifs]
>  #6 [ffff9965007c3ea0] __fput at ffffffff9b0efa6e
>  #7 [ffff9965007c3ee8] task_work_run at ffffffff9aef1614
>  #8 [ffff9965007c3f20] exit_to_usermode_loop at ffffffff9ae03d6f
>  #9 [ffff9965007c3f38] do_syscall_64 at ffffffff9ae0444c
>
> closing the file, and trying to down_write cifsi->lock_sem
>
>
> [0 00:48:22.839] [UN]  PID: 8857   TASK: ffff8c6914270000  CPU: 7
> COMMAND: "reopen_file"
>  #0 [ffff9965006a7cc8] __schedule at ffffffff9b6e6095
>  #1 [ffff9965006a7d58] schedule at ffffffff9b6e64df
>  #2 [ffff9965006a7d68] io_schedule at ffffffff9b6e68e2
>  #3 [ffff9965006a7d78] wait_on_page_bit at ffffffff9b03cac6
>  #4 [ffff9965006a7e10] __filemap_fdatawait_range at ffffffff9b03b028
>  #5 [ffff9965006a7ed8] filemap_write_and_wait at ffffffff9b040165
>  #6 [ffff9965006a7ef0] cifs_flush at ffffffffc0a0c2fa [cifs]
>  #7 [ffff9965006a7f10] filp_close at ffffffff9b0e93f1
>  #8 [ffff9965006a7f30] __x64_sys_close at ffffffff9b0e9a0e
>  #9 [ffff9965006a7f38] do_syscall_64 at ffffffff9ae04315
>
> in __filemap_fdatawait_range
>                         wait_on_page_writeback(page);
> for the same page of the file
>
>
>
> [0 00:48:22.718] [UN]  PID: 8855   TASK: ffff8c69142745c0  CPU: 7
> COMMAND: "reopen_file"
>  #0 [ffff9965005dfc98] __schedule at ffffffff9b6e6095
>  #1 [ffff9965005dfd28] schedule at ffffffff9b6e64df
>  #2 [ffff9965005dfd38] rwsem_down_write_slowpath at ffffffff9af283d7
>  #3 [ffff9965005dfdf0] cifs_strict_writev at ffffffffc0a0c40a [cifs]
>  #4 [ffff9965005dfe48] new_sync_write at ffffffff9b0ec1dd
>  #5 [ffff9965005dfed0] vfs_write at ffffffff9b0eed35
>  #6 [ffff9965005dff00] ksys_write at ffffffff9b0eefd9
>  #7 [ffff9965005dff38] do_syscall_64 at ffffffff9ae04315
>
>         inode_lock(inode);
>
>
> and one 'ls' later on, to see whether the rest of the mount is available
> (the test file is in the root, so we get blocked up on the directory
> ->i_rwsem), so the entire mount is unavailable
>
> [0 00:36:26.473] [UN]  PID: 9802   TASK: ffff8c691436ae80  CPU: 4
> COMMAND: "ls"
>  #0 [ffff996500393d28] __schedule at ffffffff9b6e6095
>  #1 [ffff996500393db8] schedule at ffffffff9b6e64df
>  #2 [ffff996500393dc8] rwsem_down_read_slowpath at ffffffff9b6e9421
>  #3 [ffff996500393e78] down_read_killable at ffffffff9b6e95e2
>  #4 [ffff996500393e88] iterate_dir at ffffffff9b103c56
>  #5 [ffff996500393ec8] ksys_getdents64 at ffffffff9b104b0c
>  #6 [ffff996500393f30] __x64_sys_getdents64 at ffffffff9b104bb6
>  #7 [ffff996500393f38] do_syscall_64 at ffffffff9ae04315
>
> in iterate_dir:
>         if (shared)
>                 res = down_read_killable(&inode->i_rwsem);  <<<<
>         else
>                 res = down_write_killable(&inode->i_rwsem);
>

Reported-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:17:12 -06:00
Aurelien Aptel d70e9fa558 cifs: try opening channels after mounting
After doing mount() successfully we call cifs_try_adding_channels()
which will open as many channels as it can.

Channels are closed when the master session is closed.

The master connection becomes the first channel.

,-------------> global cifs_tcp_ses_list <-------------------------.
|                                                                  |
'- TCP_Server_Info  <-->  TCP_Server_Info  <-->  TCP_Server_Info <-'
      (master con)           (chan#1 con)         (chan#2 con)
      |      ^                    ^                    ^
      v      '--------------------|--------------------'
   cifs_ses                       |
   - chan_count = 3               |
   - chans[] ---------------------'
   - smb3signingkey[]
      (master signing key)

Note how channel connections don't have sessions. That's because
cifs_ses can only be part of one linked list (list_head are internal
to the elements).

For signing keys, each channel has its own signing key which must be
used only after the channel has been bound. While it's binding it must
use the master session signing key.

For encryption keys, since channel connections do not have sessions
attached we must now find matching session by looping over all sessions
in smb2_get_enc_key().

Each channel is opened like a regular server connection but at the
session setup request step it must set the
SMB2_SESSION_REQ_FLAG_BINDING flag and use the session id to bind to.

Finally, while sending in compound_send_recv() for requests that
aren't negprot, ses-setup or binding related, use a channel by cycling
through the available ones (round-robin).

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:16:30 -06:00
Aurelien Aptel b8f7442bc4 CIFS: refactor cifs_get_inode_info()
Make logic of cifs_get_inode() much clearer by moving code to sub
functions and adding comments.

Document the steps this function does.

cifs_get_inode_info() gets and updates a file inode metadata from its
file path.

* If caller already has raw info data from server they can pass it.
* If inode already exists (just need to update) caller can pass it.

Step 1: get raw data from server if none was passed
Step 2: parse raw data into intermediate internal cifs_fattr struct
Step 3: set fattr uniqueid which is later used for inode number. This
        can sometime be done from raw data
Step 4: tweak fattr according to mount options (file_mode, acl to mode
        bits, uid, gid, etc)
Step 5: update or create inode from final fattr struct

* add is_smb1_server() helper
* add is_inode_cache_good() helper
* move SMB1-backupcreds-getinfo-retry to separate func
  cifs_backup_query_path_info().
* move set-uniqueid code to separate func cifs_set_fattr_ino()
* don't clobber uniqueid from backup cred retry
* fix some probable corner cases memleaks

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:16:30 -06:00
Aurelien Aptel f6a6bf7c4d cifs: switch servers depending on binding state
Currently a lot of the code to initialize a connection & session uses
the cifs_ses as input. But depending on if we are opening a new session
or a new channel we need to use different server pointers.

Add a "binding" flag in cifs_ses and a helper function that returns
the server ptr a session should use (only in the sess establishment
code path).

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:16:30 -06:00
Aurelien Aptel f780bd3fef cifs: add server param
As we get down to the transport layer, plenty of functions are passed
the session pointer and assume the transport to use is ses->server.

Instead we modify those functions to pass (ses, server) so that we
can decouple the session from the server.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:16:30 -06:00
Aurelien Aptel bcc8880115 cifs: add multichannel mount options and data structs
adds:
- [no]multichannel to enable/disable multichannel
- max_channels=N to control how many channels to create

these options are then stored in the volume struct.

- store channels and max_channels in cifs_ses

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:16:30 -06:00
Ronnie Sahlberg 87bc2376ff smb3: add debug messages for closing unmatched open
Helps distinguish between an interrupted close and a truly
unmatched open.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25 01:14:53 -06:00
Pavel Shilovsky 86a7964be7 CIFS: Fix NULL pointer dereference in mid callback
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>
2019-11-25 01:14:53 -06:00
Dave Wysochanski d46b0da7a3 cifs: Fix cifsInodeInfo lock_sem deadlock when reconnect occurs
There's a deadlock that is possible and can easily be seen with
a test where multiple readers open/read/close of the same file
and a disruption occurs causing reconnect.  The deadlock is due
a reader thread inside cifs_strict_readv calling down_read and
obtaining lock_sem, and then after reconnect inside
cifs_reopen_file calling down_read a second time.  If in
between the two down_read calls, a down_write comes from
another process, deadlock occurs.

        CPU0                    CPU1
        ----                    ----
cifs_strict_readv()
 down_read(&cifsi->lock_sem);
                               _cifsFileInfo_put
                                  OR
                               cifs_new_fileinfo
                                down_write(&cifsi->lock_sem);
cifs_reopen_file()
 down_read(&cifsi->lock_sem);

Fix the above by changing all down_write(lock_sem) calls to
down_write_trylock(lock_sem)/msleep() loop, which in turn
makes the second down_read call benign since it will never
block behind the writer while holding lock_sem.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Suggested-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed--by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-10-24 21:35:04 -05:00
Steve French d0959b080b smb3: remove noisy debug message and minor cleanup
Message was intended only for developer temporary build
In addition cleanup two minor warnings noticed by Coverity
and a trivial change to workaround a sparse warning

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-10-08 18:19:40 -07:00
Steve French c3ca78e217 smb3: pass mode bits into create calls
We need to populate an ACL (security descriptor open context)
on file and directory correct.  This patch passes in the
mode.  Followon patch will build the open context and the
security descriptor (from the mode) that goes in the open
context.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
2019-09-26 02:06:42 -05:00
Paulo Alcantara (SUSE) 8eecd1c2e5 cifs: Add support for root file systems
Introduce a new CONFIG_CIFS_ROOT option to handle root file systems
over a SMB share.

In order to mount the root file system during the init process, make
cifs.ko perform non-blocking socket operations while mounting and
accessing it.

Cc: Steve French <smfrench@gmail.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Paulo Alcantara (SUSE) <paulo@paulo.ac>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-09-16 11:43:38 -05:00
Steve French 3e7a02d478 smb3: allow disabling requesting leases
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>
2019-09-16 11:43:38 -05:00
Steve French 1b63f1840e smb3: display max smb3 requests in flight at any one time
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>
2019-09-16 11:43:38 -05:00
Steve French 563317ec30 smb3: enable offload of decryption of large reads via mount option
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>
2019-09-16 11:43:38 -05:00
Steve French 35cf94a397 smb3: allow parallelizing decryption of reads
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>
2019-09-16 11:43:38 -05:00
Steve French 4f5c10f1ad smb3: allow skipping signature verification for perf sensitive configurations
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>
2019-09-16 11:43:38 -05:00
Steve French 41e033fecd smb3: add mount option to allow RW caching of share accessed by only 1 client
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>
2019-09-16 11:43:38 -05:00
Steve French 83bbfa706d smb3: add mount option to allow forced caching of read only share
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>
2019-09-16 11:43:37 -05:00
Steve French 9fe5ff1c5d smb3: do not send compression info by default
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>
2019-07-07 22:37:43 -05:00