Commit Graph

38 Commits

Author SHA1 Message Date
Benjamin Gilbert
5b454a6455 cifs: Select all required crypto modules
Some dependencies were lost when CIFS_SMB2 was merged into CIFS.

Fixes: 2a38e12053 ("[SMB3] Remove ifdef since SMB3 (and later) now STRONGLY preferred")
Signed-off-by: Benjamin Gilbert <benjamin.gilbert@coreos.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2017-10-25 12:57:50 -05:00
Steve French
2a38e12053 [SMB3] Remove ifdef since SMB3 (and later) now STRONGLY preferred
Remove the CONFIG_CIFS_SMB2 ifdef and Kconfig option since they
must always be on now.

For various security reasons, SMB3 and later are STRONGLY preferred
over CIFS and older dialects, and SMB3 (and later) will now be
the default dialects so we do not want to allow them to be
ifdeffed out.

In the longer term, we may be able to make older CIFS support
disableable in Kconfig with a new set of #ifdef, but we always
want SMB3 and later support enabled.

Signed-off-by: Steven French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2017-07-08 18:57:07 -05:00
Aurélien Aptel
d38de3c615 CIFS: add CONFIG_CIFS_DEBUG_KEYS to dump encryption keys
Add new config option that dumps AES keys to the console when they are
generated. This is obviously for debugging purposes only, and should not
be enabled otherwise.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2017-07-05 19:51:04 -05:00
Pavel Shilovsky
026e93dc0a CIFS: Encrypt SMB3 requests before sending
This change allows to encrypt packets if it is required by a server
for SMB sessions or tree connections.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
2017-02-01 16:46:36 -06:00
Jean Delvare
3692304bba cifs: Only select the required crypto modules
The sha256 and cmac crypto modules are only needed for SMB2+, so move
the select statements to config CIFS_SMB2. Also select CRYPTO_AES
there as SMB2+ needs it.

Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Steve French <sfrench@samba.org>
2017-02-01 16:46:34 -06:00
Jean Delvare
c1ecea8747 cifs: Simplify SMB2 and SMB311 dependencies
* CIFS_SMB2 depends on CIFS, which depends on INET and selects NLS. So
  these dependencies do not need to be repeated for CIFS_SMB2.
* CIFS_SMB311 depends on CIFS_SMB2, which depends on INET. So this
  dependency doesn't need to be repeated for CIFS_SMB311.

Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Steve French <sfrench@samba.org>
2017-02-01 16:46:33 -06:00
Steve French
5f7fbf733c Allow parsing vers=3.11 on cifs mount
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: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Steve French <steve.french@primarydata.com>
2015-06-27 20:23:32 -07:00
Steve French
ca5d13fc33 Clarify Kconfig help text for CIFS and SMB2/SMB3
Clarify descriptions of SMB2 and SMB3 support in Kconfig

Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
2014-08-25 17:01:05 -05:00
Steve French
429b46f4fd [CIFS] SMB3 Signing enablement
SMB3 uses a much faster method of signing (which is also better in other ways),
AES-CMAC.  With the kernel now supporting AES-CMAC since last release, we
are overdue to allow SMB3 signing (today only CIFS and SMB2 and SMB2.1,
but not SMB3 and SMB3.1 can sign) - and we need this also for checking
secure negotation and also per-share encryption (two other new SMB3 features
which we need to implement).

This patch needs some work in a few areas - for example we need to
move signing for SMB2/SMB3 from per-socket to per-user (we may be able to
use the "nosharesock" mount option in the interim for the multiuser case),
and Shirish found a bug in the earlier authentication overhaul
(setting signing flags properly) - but those can be done in followon
patches.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-06-26 23:45:05 -05:00
Kees Cook
00f3616b25 fs/cifs: remove depends on CONFIG_EXPERIMENTAL
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

CC: Steve French <sfrench@samba.org>
CC: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-21 14:39:05 -08:00
Joe Perches
471b1f9871 cifs: Add CONFIG_CIFS_DEBUG and rename use of CIFS_DEBUG
This can reduce the size of the module by ~120KB which
could be useful for embedded systems.

$ size fs/cifs/built-in.o*
   text	   data	    bss	    dec	    hex	filename
 388567	  34459	 100440	 523466	  7fcca	fs/cifs/built-in.o.new
 495970	  34599	 117904	 648473	  9e519	fs/cifs/built-in.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
2012-12-05 14:58:36 -06:00
Steve French
1d4ab90776 [CIFS] Fix indentation of fs/cifs/Kconfig entries
make menuconfig for cifs shows multiple entries toward
the end of the list with the incorrect indentation
(probably a bug in Kconfig parsing of items
that are dependant on the module (cifs=m instead of
just CONFIG_CIFS).  This patch fixes the indentation
of all but the last entry (CIFS_ACL) which I don't
know how to fix. It also clarifies wording in
two places

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-10-01 12:48:03 -05:00
Steve French
ba02e89915 MARK SMB2 support EXPERIMENTAL
Now that the merge of the remaining pieces needed for
SMB2 (SMB2.1 dialect) are in, and most test cases pass,
we can consider SMB2.1 EXPERIMENTAL rather than "BROKEN."

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:34 -05:00
Pavel Shilovsky
3c1bf7e48e CIFS: Enable signing in SMB2
Use hmac-sha256 and rather than hmac-md5 that is used for CIFS/SMB.

Signature field in SMB2 header is 16 bytes instead of 8 bytes.

Automatically enable signing by client when requested by the server
when signing ability is available to the client.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:28 -05:00
Steve French
675f36fb1d CIFS: Introduce SMB2 Kconfig option
SMB2 is the followon to the CIFS (and SMB) protocols
and the default for Windows since Windows Vista, and also
now implemented by various non-Windows servers. SMB2
is more secure, has various performance advantages, including
larger i/o sizes, flow control, better caching model and more.
SMB2 also resolves some scalability limits in the CIFS
protocol and adds many new features while being much
simpler (only a few dozen commands instead of hundreds)
and since the protocol is clearer it is also more consistently
implemented across servers and thus easier to optimize.

After much discussion with Jeff Layton, Jeremy Allison
and others at Connectathon, we decided to move the SMB2
code from a distinct .ko and fstype into distinct
C files that optionally build in cifs.ko. As a result
the Kconfig gets simpler.

To avoid destabilizing CIFS, the SMB2 code is going
to be moved into its own experimental CONFIG_CIFS_SMB2 ifdef
as it is merged and rereviewed. The changes to stable
CIFS (builds with the SMB2 ifdef off) are expected to be
fairly small.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-05-23 12:33:14 +04:00
Steve French
2a73ca8208 [CIFS] Update cifs Kconfig title to match removal of experimental dependency
Removed the dependency on CONFIG_EXPERIMENTAL but forgot to update
the text description to be consistent.

Signed-off-by: Steve French <smfrench@gmail.com>
2012-01-31 12:51:24 -06:00
Steve French
c56001879b [CIFS] ACL and FSCACHE support no longer EXPERIMENTAL
CIFS ACL support and FSCACHE support have been in long enough
to be no longer considered experimental.  Remove obsolete Kconfig
dependency.

Signed-off-by: Steve French <sfrench@us.ibm.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
2012-01-18 17:55:41 -06:00
Jeff Layton
9b8e072a31 cifs: mark CONFIG_CIFS_NFSD_EXPORT as BROKEN
This does not work properly with CIFS as current servers do not
enable support for the FILE_OPEN_BY_FILE_ID on SMB NTCreateX
and not all NFS clients handle ESTALE.

For now, it just plain doesn't work. Mark it BROKEN to discourage
distros from enabling it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-06-24 17:33:30 +00:00
Darren Salt
243e2dd38e CIFS ACL support needs CONFIG_KEYS, so depend on it
Build fails if CONFIG_KEYS is not selected.

Signed-off-by: Darren Salt <linux@youmustbejoking.demon.co.uk>
Reviewed-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-06-06 16:58:16 +00:00
Suresh Jayaraman
5f0b23eeba cifs: make CIFS depend on CRYPTO_ECB
When CONFIG_CRYPTO_ECB is not set, trying to mount a CIFS share with NTLM
security resulted in mount failure with the following error:
   "CIFS VFS: could not allocate des crypto API"

Seems like a leftover from commit 43988d7.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
CC: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-06-03 17:38:44 +00:00
Christoph Hellwig
c02324a6ae cifs: remove unused SMB2 config and mount options
There's no SMB2 support in the CIFS filesystem driver, so there's no need to
have a config and mount option for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-05-23 18:08:05 +00:00
Steve French
43988d7685 [CIFS] Use ecb des kernel crypto APIs instead of
local cifs functions (repost)

Using kernel crypto APIs for DES encryption during LM and NT hash generation
instead of local functions within cifs.
Source file smbdes.c is deleted sans four functions, one of which
uses ecb des functionality provided by kernel crypto APIs.

Remove function SMBOWFencrypt.

Add return codes to various functions such as calc_lanman_hash,
SMBencrypt, and SMBNTencrypt.  Includes fix noticed by Dan Carpenter.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
CC: Dan Carpenter <error27@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-05-19 14:10:49 +00:00
Shirish Pargaonkar
257208736a cifs: cleanup: Rename and remove config flags
Remove config flag CIFS_EXPERIMENTAL.
Do export operations under new config flag CIFS_NFSD_EXPORT

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-05-19 14:10:49 +00:00
Steve French
b34cb85cc2 Introduce SMB2 Kconfig option
SMB2 is the followon to the CIFS (and SMB) protocols
and the default for Windows since Windows Vista, and also
now implemented by various non-Windows servers.  SMB2
is more secure, has various performance advantages, including
larger i/o sizes, flow control, better caching model and more.
SMB2 also resolves some scalability limits in the cifs
protocol and adds many new features while being much
simpler (only a few dozen commands instead of hundreds)
and since the protocol is clearer it is
also more consistently implemented across servers
and thus easier to optimize.

After much discussion with Jeff Layton, Jeremy Allison
and others at Connectathon, we decided to move the smb2
code from a distinct .ko and fstype into distinct
C files that optionally build in cifs.ko.  As a result
the Kconfig gets simpler.

To avoid destabilizing cifs, the smb2 code is going
to be moved into its own experimental CONFIG_CIFS_SMB2 ifdef
as it is merged and rereviewed.  The changes to stable
cifs (builds with the smb2 ifdef off) are expected to be
fairly small.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-05-19 14:10:48 +00:00
Jeff Layton
f855f6cbeb cifs: make CIFS depend on CRYPTO_MD4
Recently CIFS was changed to use the kernel crypto API for MD4 hashes,
but the Kconfig dependencies were not changed to reflect this.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reported-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-31 15:26:07 +00:00
Shirish Pargaonkar
fbeba8bb16 cifs: Handle extended attribute name cifs_acl to generate cifs acl blob (try #4)
Add extended attribute name system.cifs_acl

Get/generate cifs/ntfs acl blob and hand over to the invoker however
it wants to parse/process it under experimental configurable option CIFS_ACL.

Do not get CIFS/NTFS ACL for xattr for attribute system.posix_acl_access

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-11-30 05:49:24 +00:00
Steve French
362d31297f [CIFS] fs/cifs/Kconfig: CIFS depends on CRYPTO_HMAC
linux-2.6.37-rc1: I compiled a kernel with CIFS which subsequently
failed with an error indicating it couldn't initialize crypto module
"hmacmd5".  CONFIG_CRYPTO_HMAC=y fixed the problem.

This patch makes CIFS depend on CRYPTO_HMAC in kconfig.

Signed-off-by: Jody Bruchon<jody@nctritech.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-11-14 03:34:30 +00:00
Shirish Pargaonkar
d2b915210b NTLM auth and sign - Define crypto hash functions and create and send keys needed for key exchange
Mark dependency on crypto modules in Kconfig.

Defining per structures sdesc and cifs_secmech which are used to store
crypto hash functions and contexts.  They are stored per smb connection
and used for all auth mechs to genereate hash values and signatures.

Allocate crypto hashing functions, security descriptiors, and respective
contexts when a smb/tcp connection is established.
Release them when a tcp/smb connection is taken down.

md5 and hmac-md5 are two crypto hashing functions that are used
throught the life of an smb/tcp connection by various functions that
calcualte signagure and ntlmv2 hash, HMAC etc.

structure ntlmssp_auth is defined as per smb connection.

ntlmssp_auth holds ciphertext which is genereated by rc4/arc4 encryption of
secondary key, a nonce using ntlmv2 session key and sent in the session key
field of the type 3 message sent by the client during ntlmssp
negotiation/exchange

A key is exchanged with the server if client indicates so in flags in
type 1 messsage and server agrees in flag in type 2 message of ntlmssp
negotiation.  If both client and agree, a key sent by client in
type 3 message of ntlmssp negotiation in the session key field.
The key is a ciphertext generated off of secondary key, a nonce, using
ntlmv2 hash via rc4/arc4.

Signing works for ntlmssp in this patch. The sequence number within
the server structure needs to be zero until session is established
i.e. till type 3 packet of ntlmssp exchange of a to be very first
smb session on that smb connection is sent.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-10-26 18:35:31 +00:00
Steve French
c8e56f1f4f Revert "[CIFS] Fix ntlmv2 auth with ntlmssp"
This reverts commit 9fbc590860.

The change to kernel crypto and fixes to ntlvm2 and ntlmssp
series, introduced a regression.  Deferring this patch series
to 2.6.37 after Shirish fixes it.

Signed-off-by: Steve French <sfrench@us.ibm.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
2010-09-08 21:10:58 +00:00
Steve French
9fbc590860 [CIFS] Fix ntlmv2 auth with ntlmssp
Make ntlmv2 as an authentication mechanism within ntlmssp
instead of ntlmv1.
Parse type 2 response in ntlmssp negotiation to pluck
AV pairs and use them to calculate ntlmv2 response token.
Also, assign domain name from the sever response in type 2
packet of ntlmssp and use that (netbios) domain name in
calculation of response.

Enable cifs/smb signing using rc4 and md5.

Changed name of the structure mac_key to session_key to reflect
the type of key it holds.

Use kernel crypto_shash_* APIs instead of the equivalent cifs functions.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-08-20 20:42:26 +00:00
Linus Torvalds
1fc7995d19 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  [DNS RESOLVER] Minor typo correction
  DNS: Fixes for the DNS query module
  cifs: Include linux/err.h for IS_ERR and PTR_ERR
  DNS: Make AFS go to the DNS for AFSDB records for unknown cells
  DNS: Separate out CIFS DNS Resolver code
  cifs: account for new creduid=0x%x parameter in spnego upcall string
  cifs: reduce false positives with inode aliasing serverino autodisable
  CIFS: Make cifs_convert_address() take a const src pointer and a length
  cifs: show features compiled in as part of DebugData
  cifs: update README

Fix up trivial conflicts in fs/cifs/cifsfs.c due to workqueue changes
2010-08-07 12:54:46 -07:00
Linus Torvalds
3b7433b8a8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (55 commits)
  workqueue: mark init_workqueues() as early_initcall()
  workqueue: explain for_each_*cwq_cpu() iterators
  fscache: fix build on !CONFIG_SYSCTL
  slow-work: kill it
  gfs2: use workqueue instead of slow-work
  drm: use workqueue instead of slow-work
  cifs: use workqueue instead of slow-work
  fscache: drop references to slow-work
  fscache: convert operation to use workqueue instead of slow-work
  fscache: convert object to use workqueue instead of slow-work
  workqueue: fix how cpu number is stored in work->data
  workqueue: fix mayday_mask handling on UP
  workqueue: fix build problem on !CONFIG_SMP
  workqueue: fix locking in retry path of maybe_create_worker()
  async: use workqueue for worker pool
  workqueue: remove WQ_SINGLE_CPU and use WQ_UNBOUND instead
  workqueue: implement unbound workqueue
  workqueue: prepare for WQ_UNBOUND implementation
  libata: take advantage of cmwq and remove concurrency limitations
  workqueue: fix worker management invocation without pending works
  ...

Fixed up conflicts in fs/cifs/* as per Tejun. Other trivial conflicts in
include/linux/workqueue.h, kernel/trace/Kconfig and kernel/workqueue.c
2010-08-07 12:42:58 -07:00
Wang Lei
1a4240f476 DNS: Separate out CIFS DNS Resolver code
Separate out the DNS resolver key type from the CIFS filesystem into its own
module so that it can be made available for general use, including the AFS
filesystem module.

This facility makes it possible for the kernel to upcall to userspace to have
it issue DNS requests, package up the replies and present them to the kernel
in a useful form.  The kernel is then able to cache the DNS replies as keys
can be retained in keyrings.

Resolver keys are of type "dns_resolver" and have a case-insensitive
description that is of the form "[<type>:]<domain_name>".  The optional <type>
indicates the particular DNS lookup and packaging that's required.  The
<domain_name> is the query to be made.

If <type> isn't given, a basic hostname to IP address lookup is made, and the
result is stored in the key in the form of a printable string consisting of a
comma-separated list of IPv4 and IPv6 addresses.

This key type is supported by userspace helpers driven from /sbin/request-key
and configured through /etc/request-key.conf.  The cifs.upcall utility is
invoked for UNC path server name to IP address resolution.

The CIFS functionality is encapsulated by the dns_resolve_unc_to_ip() function,
which is used to resolve a UNC path to an IP address for CIFS filesystem.  This
part remains in the CIFS module for now.

See the added Documentation/networking/dns_resolver.txt for more information.

Signed-off-by: Wang Lei <wang840925@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-08-05 17:17:51 +00:00
Suresh Jayaraman
3feb41cff8 cifs: add kernel config option for CIFS Client caching support
Add a kernel config option to enable local caching for CIFS.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-08-02 12:40:33 +00:00
Tejun Heo
9b64697246 cifs: use workqueue instead of slow-work
Workqueue can now handle high concurrency.  Use system_nrt_wq
instead of slow-work.

* Updated is_valid_oplock_break() to not call cifs_oplock_break_put()
  as advised by Steve French.  It might cause deadlock.  Instead,
  reference is increased after queueing succeeded and
  cifs_oplock_break() briefly grabs GlobalSMBSeslock before putting
  the cfile to make sure it doesn't put before the matching get is
  finished.

* Anton Blanchard reported that cifs conversion was using now gone
  system_single_wq.  Use system_nrt_wq which provides non-reentrance
  guarantee which is enough and much better.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Steve French <sfrench@samba.org>
Cc: Anton Blanchard <anton@samba.org>
2010-07-22 22:59:15 +02:00
Jeff Layton
3bc303c254 cifs: convert oplock breaks to use slow_work facility (try #4)
This is the fourth respin of the patch to convert oplock breaks to
use the slow_work facility.

A customer of ours was testing a backport of one of the earlier
patchsets, and hit a "Busy inodes after umount..." problem. An oplock
break job had raced with a umount, and the superblock got torn down and
its memory reused. When the oplock break job tried to dereference the
inode->i_sb, the kernel oopsed.

This patchset has the oplock break job hold an inode and vfsmount
reference until the oplock break completes.  With this, there should be
no need to take a tcon reference (the vfsmount implicitly holds one
already).

Currently, when an oplock break comes in there's a chance that the
oplock break job won't occur if the allocation of the oplock_q_entry
fails. There are also some rather nasty races in the allocation and
handling these structs.

Rather than allocating oplock queue entries when an oplock break comes
in, add a few extra fields to the cifsFileInfo struct. Get rid of the
dedicated cifs_oplock_thread as well and queue the oplock break job to
the slow_work thread pool.

This approach also has the advantage that the oplock break jobs can
potentially run in parallel rather than be serialized like they are
today.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-09-24 18:33:18 +00:00
Steve French
10e70afa75 [CIFS] DFS no longer experimental
Also updates some DFS flag definitions

Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-03-12 01:36:20 +00:00
Alexey Dobriyan
bb26b963d8 fs/Kconfig: move CIFS out
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:42 -07:00