We can not unlock/lock cifs_tcp_ses_lock while walking through ses
and tcon lists because it can corrupt list iterator pointers and
a tcon structure can be released if we don't hold an extra reference.
Fix it by moving a reconnect process to a separate delayed work
and acquiring a reference to every tcon that needs to be reconnected.
Also do not send an echo request on newly established connections.

CC: Stable <stable@vger.kernel.org>
Signed-off-by: NPavel Shilovsky <pshilov@microsoft.com>

New mount option "snapshot=<time>" to allow mounting an earlier
version of the remote volume (if such a snapshot exists on
the server).

Note that eventually specifying a snapshot time of 1 will allow
the user to mount the oldest snapshot. A subsequent patch
add the processing for that and another for actually specifying
the "time warp" create context on SMB2/SMB3 open.

Check to make sure SMB2 negotiated, and ensure that
we use a different tcon if mount same share twice
but with different snaphshot times
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

Commit 4fcd1813 ("Fix reconnect to not defer smb3 session reconnect
long after socket reconnect") changes the behaviour of the SMB2 echo
service and causes it to renegotiate after a socket reconnect. However
under default settings, the echo service could take up to 120 seconds to
be scheduled.

The patch forces the echo service to be called immediately resulting a
negotiate call being made immediately on reconnect.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Add "idsfromsid" mount option to indicate to cifs.ko that it should
try to retrieve the uid and gid owner fields from special sids in the
ACL if present.  This first patch just adds the parsing for the mount
option.
Signed-off-by: NSteve French <steve.french@primarydata.com>
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>

Add mount option "max_credits" to allow setting maximum SMB3
credits to any value from 10 to 64000 (default is 32000).
This can be useful to workaround servers with problems allocating
credits, or to throttle the client to use smaller amount of
simultaneous i/o or to workaround server performance issues.

Also adds a cap, so that even if the server granted us more than
65000 credits due to a server bug, we would not use that many.
Signed-off-by: NSteve French <steve.french@primarydata.com>

Patch a6b5058f results in -EREMOTE returned by is_path_accessible() in
cifs_mount() to be ignored which breaks DFS mounting.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

GUIDs although random, and 16 bytes, need to be generated as
proper uuids.
Signed-off-by: NSteve French <steve.french@primarydata.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Reported-by: NDavid Goebels <davidgoe@microsoft.com>
CC: Stable <stable@vger.kernel.org>

The patch
fs/cifs: make share unaccessible at root level mountable
makes use of prepaths when any component of the underlying path is
inaccessible.

When mounting 2 separate shares having different prepaths but are other
wise similar in other respects, we end up sharing superblocks when we
shouldn't be doing so.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Tested-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Fix memory leaks introduced by the patch
fs/cifs: make share unaccessible at root level mountable

Also move allocation of cifs_sb->prepath to cifs_setup_cifs_sb().
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Tested-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

if, when mounting //HOST/share/sub/dir/foo we can query /sub/dir/foo but
not any of the path components above:

- store the /sub/dir/foo prefix in the cifs super_block info
- in the superblock, set root dentry to the subpath dentry (instead of
  the share root)
- set a flag in the superblock to remember it
- use prefixpath when building path from a dentry

fixes bso#8950
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

adfeb3e0 ("cifs: Make echo interval tunable") added a comparison of
vol->echo_interval to server->echo_interval as a criterium to
match_server(), but:

 (1) A default value is set for server->echo_interval but not for
 vol->echo_interval, meaning these can never match if the echo_interval
 option is not specified.

 (2) vol->echo_interval is in seconds but server->echo_interval is in
 jiffies, meaning these can never match even if the echo_interval option
 is specified.

This broke TCP session reuse since match_server() can never return 1.
Fix it.

Fixes: adfeb3e0 ("cifs: Make echo interval tunable")
Signed-off-by: NRabin Vincent <rabinv@axis.com>
Acked-by: NSachin Prabhu <sprabhu@redhat.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

Azure server blocks clients that open a socket and don't do anything on it.
In our reconnect scenarios, we can reconnect the tcp session and
detect the socket is available but we defer the negprot and SMB3 session
setup and tree connect reconnection until the next i/o is requested, but
this looks suspicous to some servers who expect SMB3 negprog and session
setup soon after a socket is created.

In the echo thread, reconnect SMB3 sessions and tree connections
that are disconnected.  A later patch will replay persistent (and
resilient) handle opens.

CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <steve.french@primarydata.com>
Acked-by: NPavel Shilovsky <pshilovsky@samba.org>

We currently do not check if any delimiter exists before the prefix
path in cifs_compose_mount_options(). Consequently when building the
devname using cifs_build_devname() we can end up with multiple
delimiters separating the UNC and the prefix path.

An issue was reported by the customer mounting a folder within a DFS
share from a Netapp server which uses McAfee antivirus. We have
narrowed down the cause to the use of double backslashes in the file
name used to open the file. This was determined to be caused because of
additional delimiters as a result of the bug.

In addition to changes in cifs_build_devname(), we also fix
cifs_parse_devname() to ignore any preceding delimiter for the prefix
path.

The problem was originally reported on RHEL 6 in RHEL bz 1252721. This
is the upstream version of the fix. The fix was confirmed by looking at
the packet capture of a DFS mount.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

sock_owned_by_user should not be used without socket lock held. It seems
to be a common practice to check .owned before lock reclassification, so
provide a little help to abstract this check away.

Cc: linux-cifs@vger.kernel.org
Cc: linux-bluetooth@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

just do ITER_BVEC recvmsg
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

server_RFC1001_name is declared as a RFC1001_NAME_LEN_WITH_NULL sized
char array in struct TCP_Server_Info so the null pointer check on
server_RFC1001_name is redundant and can be removed.  Detected with
smatch:

fs/cifs/connect.c:2982 ip_rfc1001_connect() warn: this array is probably
  non-NULL. 'server->server_RFC1001_name'
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

cifs_call_async() queues the MID to the pending list and calls
smb_send_rqst().  If smb_send_rqst() performs a partial send, it sets
the tcpStatus to CifsNeedReconnect and returns an error code to
cifs_call_async().  In this case, cifs_call_async() removes the MID
from the list and returns to the caller.

However, cifs_call_async() releases the server mutex _before_ removing
the MID.  This means that a cifs_reconnect() can race with this function
and manage to remove the MID from the list and delete the entry before
cifs_call_async() calls cifs_delete_mid().  This leads to various
crashes due to the use after free in cifs_delete_mid().

Task1				Task2

cifs_call_async():
 - rc = -EAGAIN
 - mutex_unlock(srv_mutex)

				cifs_reconnect():
				 - mutex_lock(srv_mutex)
				 - mutex_unlock(srv_mutex)
				 - list_delete(mid)
				 - mid->callback()
				 	cifs_writev_callback():
				 		- mutex_lock(srv_mutex)
						- delete(mid)
				 		- mutex_unlock(srv_mutex)

 - cifs_delete_mid(mid) <---- use after free

Fix this by removing the MID in cifs_call_async() before releasing the
srv_mutex.  Also hold the srv_mutex in cifs_reconnect() until the MIDs
are moved out of the pending list.
Signed-off-by: NRabin Vincent <rabin.vincent@axis.com>
Acked-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: NSteve French <sfrench@localhost.localdomain>

Prepare for encryption support (first part). Add decryption and encryption key generation. Thanks to Metze for helping with this.
Reviewed-by: NStefan Metzmacher <metze@samba.org>
Signed-off-by: NSteve French <steve.french@primarydata.com>

Currently the echo interval is set to 60 seconds using a macro. This
setting determines the interval at which echo requests are sent to the
server on an idling connection. This setting also affects the time
required for a connection to an unresponsive server to timeout.

Making this setting a tunable allows users to control the echo interval
times as well as control the time after which the connecting to an
unresponsive server times out.

To set echo interval, pass the echo_interval=n mount option.

Version four of the patch.
v2: Change MIN and MAX timeout values
v3: Remove incorrect comment in cifs_get_tcp_session
v4: Fix bug in setting echo_intervalw
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Acked-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>

Before this patch, only the hostname of the server
is printed when it becomes unresponsive.
This might not be helpful, if the IP-Address has
changed since initial mount when the name was
resolved (e.g. because the IPv6-Prefix changed).

This patch adds the cached IP address of the unresponsive server,
to the log message.
Signed-off-by: NArnd Hannemann <arnd@arndnet.de>
Signed-off-by: NSteve French <sfrench@localhost.localdomain>

Since many servers (Windows clients, and non-clustered servers) do not
support persistent handles but do support resilient handles, allow
the user to specify a mount option "resilienthandles" in order
to get more reliable connections and less chance of data loss
(at least when SMB2.1 or later).  Default resilient handle
timeout (120 seconds to recent Windows server) is used.
Reviewed-by: NPavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: NSteve French <steve.french@primarydata.com>

Validate "persistenthandles" and "nopersistenthandles" mount options against
the support the server claims in negotiate and tree connect SMB3 responses.
Signed-off-by: NSteve French <steve.french@primarydata.com>
Reviewed-by: NPavel Shilovsky <pshilovsky@samba.org>

"nopersistenthandles" and "persistenthandles" mount options added.
The former will not request persistent handles on open even when
SMB3 negotiated and Continuous Availability share.  The latter
will request persistent handles (as long as server notes the
capability in protocol negotiation) even if share is not Continuous
Availability share.
Signed-off-by: NSteve French <steve.french@primarydata.com>
Reviewed-by: NPavel Shilovsky <pshilovsky@samba.org>

Merge the type-specific data with the payload data into one four-word chunk
as it seems pointless to keep them separate.

Use user_key_payload() for accessing the payloads of overloaded
user-defined keys.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: linux-cifs@vger.kernel.org
cc: ecryptfs@vger.kernel.org
cc: linux-ext4@vger.kernel.org
cc: linux-f2fs-devel@lists.sourceforge.net
cc: linux-nfs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: linux-ima-devel@lists.sourceforge.net

In a dfs setup where the client transitions from a server which supports
posix paths to a server which doesn't support posix paths, the flag
CIFS_MOUNT_POSIX_PATHS is not reset. This leads to the wrong directory
separator being used causing smb commands to fail.

Consider the following case where a dfs share on a samba server points
to a share on windows smb server.
 # mount -t cifs -o .. //vm140-31/dfsroot/testwin/
 # ls -l /mnt; touch /mnt/a
 total 0
 touch: cannot touch ‘/mnt/a’: No such file or directory
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Acked-by: NJeff Layton <jlayton@samba.org>
Signed-off-by: NSteve French <steve.french@primarydata.com>

Most people think of SMB 3.1.1 as SMB version 3.11 so add synonym
for "vers=3.1.1" of "vers=3.11" on mount.

Also make sure that unlike SMB3.0 and 3.02 we don't send
validate negotiate on mount (it is handled by negotiate contexts) -
add list of SMB3.11 specific functions (distinct from 3.0 dialect).

Signed-off-by: Steve French <steve.french@primarydata.com>w

Parses and recognizes "vers=3.1.1" on cifs mount and allows sending
0x0311 as a new CIFS/SMB3 dialect. Subsequent patches will add
the new negotiate contexts and updated session setup
Reviewed-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NSteve French <steve.french@primarydata.com>

This patch fixes a race condition that occurs when connecting
to a NT 3.51 host without specifying a NetBIOS name.
In that case a RFC1002_NEGATIVE_SESSION_RESPONSE is received
and the SMB negotiation is reattempted, but under some conditions
it leads SendReceive() to hang forever while waiting for srv_mutex.
This, in turn, sets the calling process to an uninterruptible sleep
state and makes it unkillable.

The solution is to unlock the srv_mutex acquired in the demux
thread *before* going to sleep (after the reconnect error) and
before reattempting the connection.

Allocating a large number of elements in atomic context could quickly
deplete memory reserves, so just disallow atomic resizing entirely.

Nothing currently uses mempool_resize() with anything other than
GFP_KERNEL, so convert existing callers to drop the gfp_mask.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Acked-by: Steffen Maier <maier@linux.vnet.ibm.com>	[zfcp]
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

workstation_RFC1001_name is part of the struct and can't be null,
remove impossible comparison (array vs. null)

Pointed out by Coverity (CID 140095)
Signed-off-by: NSteve French <smfrench@gmail.com>
Reviewed-by: NJeff Layton <jlayton@samba.org>

Although unlikely to fail (and tree connect does not commonly send
a password since SECMODE_USER is the default for most servers)
do not ignore errors on SMBNTEncrypt in SMB Tree Connect.

Reported by Coverity (CID 1226853)
Signed-off-by: NSteve French <smfrench@gmail.com>
Acked-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NJeff Layton <jlayton@poochiereds.net>

For example, when mount opt is redundently specified
(e.g., "user=A,user=B,user=C"), kernel kept allocating new key/val
with kstrdup() and overwrite previous ptr (to be freed).

Althouhg mount.cifs in userspace performs a bit of sanitization
(e.g., forcing one user option), current implementation is not
robust. Other options such as iocharset and domainanme are similarly
vulnerable.
Signed-off-by: NTaesoo Kim <tsgatesv@gmail.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead.  Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device.  It also removes the need for
the mtd_inodefs filesystem.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NTejun Heo <tj@kernel.org>
Acked-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

The useful macros embed message level in the name. Thus, it cleans up the code
a bit. In cases when it was plain printk() the conversion was done to info
level.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NSteve French <steve.french@primarydata.com>

This is a bigger patch, but its size is mostly due to
a single change for how we check for remapping illegal characters
in file names - a lot of repeated, small changes to
the way callers request converting file names.

The final patch in the series does the following:

1) changes default behavior for cifs to be more intuitive.
Currently we do not map by default to seven reserved characters,
ie those valid in POSIX but not in NTFS/CIFS/SMB3/Windows,
unless a mount option (mapchars) is specified.  Change this
to by default always map and map using the SFM maping
(like the Mac uses) unless the server negotiates the CIFS Unix
Extensions (like Samba does when mounting with the cifs protocol)
when the remapping of the characters is unnecessary.  This should
help SMB3 mounts in particular since Samba will likely be
able to implement this mapping with its new "vfs_fruit" module
as it will be doing for the Mac.
2) if the user specifies the existing "mapchars" mount option then
use the "SFU" (Microsoft Services for Unix, SUA) style mapping of
the seven characters instead.
3) if the user specifies "nomapposix" then disable SFM/MAC style mapping
(so no character remapping would be used unless the user specifies
"mapchars" on mount as well, as above).
4) change all the places in the code that check for the superblock
flag on the mount which is set by mapchars and passed in on all
path based operation and change it to use a small function call
instead to set the mapping type properly (and check for the
mapping type in the cifs unicode functions)
Signed-off-by: NSteve French <smfrench@gmail.com>

The "sfu" mount option did not work on SMB2/SMB3 mounts.
With these changes when the "sfu" mount option is passed in
on an smb2/smb2.1/smb3 mount the client can emulate (and
recognize) fifo and device (character and device files).

In addition the "sfu" mount option should not conflict
with "mfsymlinks" (symlink emulation) as we will never
create "sfu" style symlinks, but using "sfu" mount option
will allow us to recognize existing symlinks, created with
Microsoft "Services for Unix" (SFU and SUA).

To enable the "sfu" mount option for SMB2/SMB3 the calling
syntax of the generic cifs/smb2/smb3 sync_read and sync_write
protocol dependent function needed to be changed (we
don't have a file struct in all cases), but this actually
ended up simplifying the code a little.
Signed-off-by: NSteve French <smfrench@gmail.com>

The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp.  The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.

To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 52a36244.

Causes rmmod to fail for at least 7 seconds after unmount which
makes automated testing a little harder when reloading cifs.ko
between test runs.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
CC: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: NSteve French <smfrench@gmail.com>