Commit graph

102 commits

Author SHA1 Message Date
Tim Gardner
3d378d3fd8 cifs: Make big endian multiplex ID sequences monotonic on the wire
The multiplex identifier (MID) in the SMB header is only
ever used by the client, in conjunction with PID, to match responses
from the server. As such, the endianess of the MID is not important.
However, When tracing packet sequences on the wire, protocol analyzers
such as wireshark display MID as little endian. It is much more informative
for the on-the-wire MID sequences to match debug information emitted by the
CIFS driver.  Therefore, one should write and read MID in the SMB header
assuming it is always little endian.

Observed from wireshark during the protocol negotiation
and session setup:

        Multiplex ID: 256
        Multiplex ID: 256
        Multiplex ID: 512
        Multiplex ID: 512
        Multiplex ID: 768
        Multiplex ID: 768

After this patch on-the-wire MID values begin at 1 and increase monotonically.

Introduce get_next_mid64() for the internal consumers that use the full 64 bit
multiplex identifier.

Introduce the helpers get_mid() and compare_mid() to make the endian
translation clear.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Tim Gardner <timg@tpi.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-11-02 12:51:53 -05:00
Tim Gardner
944d6f1a5b cifs: Remove redundant multiplex identifier check from check_smb_hdr()
The only call site for check_smb_header() assigns 'mid' from the SMB
packet, which is then checked again in check_smb_header(). This seems
like redundant redundancy.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Tim Gardner <timg@tpi.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-10-28 09:31:36 -05:00
Pavel Shilovsky
18cceb6a78 CIFS: Replace clientCanCache* bools with an integer
that prepare the code to handle different types of SMB2 leases.

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-08 17:49:17 -05:00
Shirish Pargaonkar
d4e63bd6e4 cifs: Process post session setup code in respective dialect functions.
Move the post (successful) session setup code to respective dialect routines.

For smb1, session key is per smb connection.
For smb2/smb3, session key is per smb session.

If client and server do not require signing, free session key for smb1/2/3.

If client and server require signing
  smb1 - Copy (kmemdup) session key for the first session to connection.
         Free session key of that and subsequent sessions on this connection.
  smb2 - For every session, keep the session key and free it when the
         session is being shutdown.
  smb3 - For every session, generate the smb3 signing key using the session key
         and then free the session key.

There are two unrelated line formatting changes as well.

Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-08 14:47:47 -05:00
Jeff Layton
38d77c50b4 cifs: track the enablement of signing in the TCP_Server_Info
Currently, we determine this according to flags in the sec_mode, flags
in the global_secflags and via other methods. That makes the semantics
very hard to follow and there are corner cases where we don't handle
this correctly.

Add a new bool to the TCP_Server_Info that acts as a simple flag to tell
us whether signing is enabled on this connection or not, and fix up the
places that need to determine this to use that flag.

This is a bit weird for the SMB2 case, where signing is per-session.
SMB2 needs work in this area already though. The existing SMB2 code has
similar logic to what we're using here, so there should be no real
change in behavior. These changes should make it easier to implement
per-session signing in the future though.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-06-24 01:56:43 -05:00
Joe Perches
f96637be08 [CIFS] cifs: Rename cERROR and cFYI to cifs_dbg
It's not obvious from reading the macro names that these macros
are for debugging.  Convert the names to a single more typical
kernel style cifs_dbg macro.

	cERROR(1, ...)   -> cifs_dbg(VFS, ...)
	cFYI(1, ...)     -> cifs_dbg(FYI, ...)
	cFYI(DBG2, ...)  -> cifs_dbg(NOISY, ...)

Move the terminating format newline from the macro to the call site.

Add CONFIG_CIFS_DEBUG function cifs_vfs_err to emit the
"CIFS VFS: " prefix for VFS messages.

Size is reduced ~ 1% when CONFIG_CIFS_DEBUG is set (default y)

$ size fs/cifs/cifs.ko*
   text    data     bss     dec     hex filename
 265245	   2525	    132	 267902	  4167e	fs/cifs/cifs.ko.new
 268359    2525     132  271016   422a8 fs/cifs/cifs.ko.old

Other miscellaneous changes around these conversions:

o Miscellaneous typo fixes
o Add terminating \n's to almost all formats and remove them
  from the macros to be more kernel style like.  A few formats
  previously had defective \n's
o Remove unnecessary OOM messages as kmalloc() calls dump_stack
o Coalesce formats to make grep easier,
  added missing spaces when coalescing formats
o Use %s, __func__ instead of embedded function name
o Removed unnecessary "cifs: " prefixes
o Convert kzalloc with multiply to kcalloc
o Remove unused cifswarn macro

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-05-04 22:17:23 -05:00
Eric W. Biederman
1f68233c52 cifs: Convert struct cifs_sb_info to use kuids and kgids
Cc: Steve French <smfrench@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-02-13 07:28:54 -08:00
Pavel Shilovsky
233839b1df CIFS: Fix fast lease break after open problem
Now we walk though cifsFileInfo's list for every incoming lease
break and look for an equivalent there. That approach misses lease
breaks that come just after an open response - we don't have time
to populate new cifsFileInfo structure to the list. Fix this by
adding new list of pending opens and look for a lease there if we
didn't find it in the list of cifsFileInfo structures.

Signed-off-by: Pavel Shilovsky <pshilovsky@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-09-24 21:46:33 -05:00
Pavel Shilovsky
4b4de76e35 CIFS: Replace netfid with cifs_fid struct in cifsFileInfo
This is help us to extend the code for future protocols that can use
another fid mechanism (as SMB2 that has it divided into two parts:
persistent and violatile).

Also rename variables and refactor the code around the changes.

Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:26 -05:00
Pavel Shilovsky
44c581866e CIFS: Move clear/print_stats code to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:18 +04:00
Pavel Shilovsky
3792c17328 CIFS: Respect SMB2 header/max header size
Use SMB2 header size values for allocation and memset because they
are bigger and suitable for both CIFS and SMB2.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:54:54 +04:00
Pavel Shilovsky
6d5786a34d CIFS: Rename Get/FreeXid and make them work with unsigned int
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 10:25:08 -05:00
Pavel Shilovsky
8825736060 CIFS: Move get_next_mid to ops struct
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-06-01 12:35:19 -05:00
Pavel Shilovsky
452757897a CIFS: Move add/set_credits and get_credits_field to ops structure
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-05-23 12:33:12 +04:00
Jeff Layton
5e500ed125 cifs: remove legacy MultiuserMount option
We've now warned about this for two releases. Remove it for 3.5.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2012-05-16 20:13:31 -05:00
Jeff Layton
da472fc847 cifs: add new cifsiod_wq workqueue
...and convert existing cifs users of system_nrt_wq to use that instead.

Also, make it freezable, and set WQ_MEM_RECLAIM since we use it to
deal with write reply handling.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
2012-03-23 14:40:53 -04:00
Pavel Shilovsky
7c9421e1a9 CIFS: Change mid_q_entry structure fields
to be protocol-unspecific and big enough to keep both CIFS
and SMB2 values.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
2012-03-23 14:28:03 -04:00
Pavel Shilovsky
243d04b6e6 CIFS: Expand CurrentMid field
While in CIFS/SMB we have 16 bit mid, in SMB2 it is 64 bit.
Convert the existing field to 64 bit and mask off higher bits
for CIFS/SMB.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
2012-03-23 14:28:03 -04:00
Pavel Shilovsky
d4e4854fd1 CIFS: Separate protocol-specific code from demultiplex code
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
2012-03-23 14:28:02 -04:00
Pavel Shilovsky
792af7b05b CIFS: Separate protocol-specific code from transport routines
that lets us use this functions for SMB2.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
2012-03-23 14:28:02 -04:00
Pavel Shilovsky
2d86dbc970 CIFS: Introduce credit-based flow control
and send no more than credits value requests at once. For SMB/CIFS
it's trivial: increment this value by receiving any message and
decrement by sending one.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-03-21 11:35:03 -05:00
Shirish Pargaonkar
3d3ea8e64e cifs: Add mount options for backup intent (try #6)
Add mount options backupuid and backugid.

It allows an authenticated user to access files with the intent to back them
up including their ACLs, who may not have access permission but has
"Backup files and directories user right" on them (by virtue of being part
of the built-in group Backup Operators.

When mount options backupuid is specified, cifs client restricts the
use of backup intents to the user whose effective user id is specified
along with the mount option.

When mount options backupgid is specified, cifs client restricts the
use of backup intents to the users whose effective user id belongs to the
group id specified along with the mount option.

If an authenticated user is not part of the built-in group Backup Operators
at the server, access to such files is denied, even if allowed by the client.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:42:17 -05:00
Jeff Layton
376b43f41c cifs: clean up checkSMB
The variable names in this function are so ambiguous that it's very
difficult to know what it's doing. Rename them to make it a bit more
clear.

Also, remove a redundant length check. cifsd checks to make sure that
the rfclen isn't larger than the maximum frame size when it does the
receive.

Finally, change checkSMB to return a real error code (-EIO) when
it finds an error. That will help simplify some coming changes in the
callers.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-10-12 23:41:36 -05:00
Jeff Layton
ad635942c8 cifs: simplify refcounting for oplock breaks
Currently, we take a sb->s_active reference and a cifsFileInfo reference
when an oplock break workqueue job is queued. This is unnecessary and
more complicated than it needs to be. Also as Al points out,
deactivate_super has non-trivial locking implications so it's best to
avoid that if we can.

Instead, just cancel any pending oplock breaks for this filehandle
synchronously in cifsFileInfo_put after taking it off the lists.
That should ensure that this job doesn't outlive the structures it
depends on.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-07-31 21:21:20 +00:00
Steve French
96daf2b091 [CIFS] Rename three structures to avoid camel case
secMode to sec_mode
and
cifsTconInfo to cifs_tcon
and
cifsSesInfo to cifs_ses

Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-05-27 04:34:02 +00:00
Jeff Layton
820a803ffa cifs: keep BCC in little-endian format
This is the same patch as originally posted, just with some merge
conflicts fixed up...

Currently, the ByteCount is usually converted to host-endian on receive.
This is confusing however, as we need to keep two sets of routines for
accessing it, and keep track of when to use each routine. Munging
received packets like this also limits when the signature can be
calulated.

Simplify the code by keeping the received ByteCount in little-endian
format. This allows us to eliminate a set of routines for accessing it
and we can now drop the *_le suffixes from the accessor functions since
that's now implied.

While we're at it, switch all of the places that read the ByteCount
directly to use the get_bcc inline which should also clean up some
unaligned accesses.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-05-19 14:10:53 +00:00
Steve French
be8e3b0044 consistently use smb_buf_length as be32 for cifs (try 3)
There is one big endian field in the cifs protocol, the RFC1001
       length, which cifs code (unlike in the smb2 code) had been handling as
       u32 until the last possible moment, when it was converted to be32 (its
       native form) before sending on the wire.   To remove the last sparse
       endian warning, and to make this consistent with the smb2
       implementation  (which always treats the fields in their
       native size and endianness), convert all uses of smb_buf_length to
       be32.

       This version incorporates Christoph's comment about
       using be32_add_cpu, and fixes a typo in the second
       version of the patch.

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>
2011-05-19 14:10:51 +00:00
Jeff Layton
8679b0dba7 cifs: fix broken BCC check in is_valid_oplock_break
The BCC is still __le16 at this point, and in any case we need to
use the get_bcc_le macro to make sure we don't hit alignment
problems.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-04-12 00:54:30 +00:00
Steve French
8727c8a85f Allow user names longer than 32 bytes
We artificially limited the user name to 32 bytes, but modern servers handle
larger.  Set the maximum length to a reasonable 256, and make the user name
string dynamically allocated rather than a fixed size in session structure.
Also clean up old checkpatch warning.

Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-04-12 00:42:06 +00:00
Jeff Layton
6284644e8d cifs: fix length checks in checkSMB
The cERROR message in checkSMB when the calculated length doesn't match
the RFC1001 length is incorrect in many cases. It always says that the
RFC1001 length is bigger than the SMB, even when it's actually the
reverse.

Fix the error message to say the reverse of what it does now when the
SMB length goes beyond the end of the received data. Also, clarify the
error message when the RFC length is too big. Finally, clarify the
comments to show that the 512 byte limit on extra data at the end of
the packet is arbitrary.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-31 22:35:37 +00:00
Jeff Layton
92a4e0f016 cifs: force a reconnect if there are too many MIDs in flight
Currently, we allow the pending_mid_q to grow without bound with
SIGKILL'ed processes. This could eventually be a DoS'able problem. An
unprivileged user could a process that does a long-running call and then
SIGKILL it.

If he can also intercept the NT_CANCEL calls or the replies from the
server, then the pending_mid_q could grow very large, possibly even to
2^16 entries which might leave GetNextMid in an infinite loop. Fix this
by imposing a hard limit of 32k calls per server. If we cross that
limit, set the tcpStatus to CifsNeedReconnect to force cifsd to
eventually reconnect the socket and clean out the pending_mid_q.

While we're at it, clean up the function a bit and eliminate an
unnecessary NULL pointer check.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-31 04:38:15 +00:00
Jeff Layton
68abaffa6b cifs: simplify SMB header check routine
...just cleanup. There should be no behavior change.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-31 04:30:37 +00:00
Jeff Layton
84cdf74e80 cifs: fix unaligned accesses in cifsConvertToUCS
Move cifsConvertToUCS to cifs_unicode.c where all of the other unicode
related functions live. Have it store mapped characters in 'temp' and
then use put_unaligned_le16 to copy it to the target buffer. Also fix
the comments to match kernel coding style.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-20 21:48:00 +00:00
Pavel Shilovsky
12fed00de9 CIFS: Fix oplock break handling (try #2)
When we get oplock break notification we should set the appropriate
value of OplockLevel field in oplock break acknowledge according to
the oplock level held by the client in this time. As we only can have
level II oplock or no oplock in the case of oplock break, we should be
aware only about clientCanCacheRead field in cifsInodeInfo structure.

Also fix bug connected with wrong interpretation of OplockLevel field
during oplock break notification processing.

Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-19 17:52:29 +00:00
Pavel Shilovsky
c67236281c cifs: make cifs_set_oplock_level() take a cifsInodeInfo pointer
All the callers already have a pointer to struct cifsInodeInfo. Use it.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-11-05 17:39:01 +00:00
Pavel Shilovsky
e66673e39a CIFS: Add cifs_set_oplock_level
Simplify many places when we need to set oplock level on an inode.

Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-11-02 18:40:54 +00:00
Suresh Jayaraman
6573e9b73e cifs: update comments - [s/GlobalSMBSesLock/cifs_file_list_lock/g]
GlobalSMBSesLock is now cifs_file_list_lock. Update comments to reflect this.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-10-25 00:19:01 +00:00
Steve French
cdff08e766 [CIFS] move close processing from cifs_close to cifsFileInfo_put
Now that it's feasible for a cifsFileInfo to outlive the filp under
which it was created, move the close processing into cifsFileInfo_put.

This means that the last user of the filehandle always does the actual
on the wire close call. This also allows us to get rid of the closePend
flag from cifsFileInfo. If we have an active reference to the file
then it's never going to have a close pending.

cifs_close is converted to simply put the filehandle.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-10-21 22:46:14 +00:00
Suresh Jayaraman
3f9bcca782 cifs: convert cifs_tcp_ses_lock from a rwlock to a spinlock
cifs_tcp_ses_lock is a rwlock with protects the cifs_tcp_ses_list,
server->smb_ses_list and the ses->tcon_list. It also protects a few
ref counters in server, ses and tcon. In most cases the critical section
doesn't seem to be large, in a few cases where it is slightly large, there
seem to be really no benefit from concurrent access. I briefly considered RCU
mechanism but it appears to me that there is no real need.

Replace it with a spinlock and get rid of the last rwlock in the cifs code.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-10-21 13:14:27 +00:00
Jeff Layton
4477288a10 cifs: convert GlobalSMBSeslock from a rwlock to regular spinlock
Convert this lock to a regular spinlock

A rwlock_t offers little value here. It's more expensive than a regular
spinlock unless you have a fairly large section of code that runs under
the read lock and can benefit from the concurrency.

Additionally, we need to ensure that the refcounting for files isn't
racy and to do that we need to lock areas that can increment it for
write. That means that the areas that can actually use a read_lock are
very few and relatively infrequently used.

While we're at it, change the name to something easier to type, and fix
a bug in find_writable_file. cifsFileInfo_put can sleep and shouldn't be
called while holding the lock.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-10-18 01:32:01 +00:00
Jeff Layton
a5e18bc36e cifs: keep dentry reference in cifsFileInfo instead of inode reference
cifsFileInfo is a bit problematic. It contains a reference back to the
struct file itself. This makes it difficult for a cifsFileInfo to exist
without a corresponding struct file.

It would be better instead of the cifsFileInfo just held info pertaining
to the open file on the server instead without any back refrences to the
struct file. This would allow it to exist after the filp to which it was
originally attached was closed.

Much of the use of the file pointer in this struct is to get at the
dentry.  Begin divorcing the cifsFileInfo from the struct file by
keeping a reference to the dentry. Since the dentry will have a
reference to the inode, we can eliminate the "pInode" field too and
convert the igrab/iput to dget/dput.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-10-12 18:06:42 +00:00
Jeff Layton
0d424ad0a4 cifs: add cifs_sb_master_tcon and convert some callers to use it
At mount time, we'll always need to create a tcon that will serve as a
template for others that are associated with the mount. This tcon is
known as the "master" tcon.

In some cases, we'll need to use that tcon regardless of who's accessing
the mount. Add an accessor function for the master tcon and go ahead and
switch the appropriate places to use it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-09-29 19:04:33 +00:00
Jeff Layton
a6e8a8455c cifs: add function to get a tcon from cifs_sb
When we convert cifs to do multiple sessions per mount, we'll need more
than one tcon per superblock. At that point "cifs_sb->tcon" will make
no sense. Add a new accessor function that gets a tcon given a cifs_sb.
For now, it just returns cifs_sb->tcon. Later it'll do more.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-09-29 19:04:32 +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
Joe Perches
b6b38f704a [CIFS] Neaten cERROR and cFYI macros, reduce text space
Neaten cERROR and cFYI macros, reduce text space
~2.5K

Convert '__FILE__ ": " fmt' to '"%s: " fmt', __FILE__' to save text space
Surround macros with do {} while
Add parentheses to macros
Make statement expression macro from macro with assign
Remove now unnecessary parentheses from cFYI and cERROR uses

defconfig with CIFS support old
$ size fs/cifs/built-in.o
   text	   data	    bss	    dec	    hex	filename
 156012	   1760	    148	 157920	  268e0	fs/cifs/built-in.o

defconfig with CIFS support old
$ size fs/cifs/built-in.o
   text	   data	    bss	    dec	    hex	filename
 153508	   1760	    148	 155416	  25f18	fs/cifs/built-in.o

allyesconfig old:
$ size fs/cifs/built-in.o
   text	   data	    bss	    dec	    hex	filename
 309138	   3864	  74824	 387826	  5eaf2	fs/cifs/built-in.o

allyesconfig new
$ size fs/cifs/built-in.o
   text	   data	    bss	    dec	    hex	filename
 305655	   3864	  74824	 384343	  5dd57	fs/cifs/built-in.o

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-04-21 03:50:45 +00:00
Steve French
d7b619cf56 [CIFS] pSesInfo->sesSem is used as mutex. Rename it to session_mutex and
convert it to a real mutex.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-02-25 05:36:46 +00:00
Suresh Jayaraman
f534dc9943 cifs: clear server inode number flag while autodisabling
Fix the commit ec06aedd44 that intended to turn off querying for server inode
numbers when server doesn't consistently support inode numbers. Presumably
the commit didn't actually clear the CIFS_MOUNT_SERVER_INUM flag, perhaps a
typo.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: Stable <stable@kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-11-16 15:24:03 +00:00
Jeff Layton
ec06aedd44 cifs: clean up handling when server doesn't consistently support inode numbers
It's possible that a server will return a valid FileID when we query the
FILE_INTERNAL_INFO for the root inode, but then zeroed out inode numbers
when we do a FindFile with an infolevel of
SMB_FIND_FILE_ID_FULL_DIR_INFO.

In this situation turn off querying for server inode numbers, generate a
warning for the user and just generate an inode number using iunique.
Once we generate any inode number with iunique we can no longer use any
server inode numbers or we risk collisions, so ensure that we don't do
that in cifs_get_inode_info either.

Cc: Stable <stable@kernel.org>
Reported-by: Timothy Normand Miller <theosib@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-11-06 22:04:37 +00:00
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
Jeff Layton
058daf4f67 cifs: take read lock on GlobalSMBSes_lock in is_valid_oplock_break
...rather than a write lock. It doesn't change the list so a read lock
should be sufficient.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-09-15 19:45:10 +00:00