Commit Graph

340 Commits

Author SHA1 Message Date
Pavel Shilovsky d244bf2dfb CIFS: Implement follow_link for nounix CIFS mounts
by using a query reparse ioctl request.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-08 14:27:41 -05:00
David Disseldorp 7ac0febb81 cifs: fill TRANS2_QUERY_FILE_INFO ByteCount fields
Currently the trans2 ByteCount field is incorrectly left zero in
TRANS2_QUERY_FILE_INFO info_level=SMB_QUERY_FILE_ALL_INFO and
info_level=SMB_QUERY_FILE_UNIX_BASIC requests. The field should properly
reflect the FID, information_level and padding bytes carried in these
requests.

Leaving this field zero causes such requests to fail against Novell CIFS
servers. Other SMB servers (e.g. Samba) use the parameter count fields
for data length calculations instead, so do not suffer the same fate.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-06-29 00:09:44 -05:00
Jeff Layton 50285882fd cifs: fix SMB2 signing enablement in cifs_enable_signing
Commit 9ddec56131 (cifs: move handling of signed connections into
separate function) broke signing on SMB2/3 connections. While the code
to enable signing on the connections was very similar between the two,
the bits that get set in the sec_mode are different.

Declare a couple of new smb_version_values fields and set them
appropriately for SMB1 and SMB2/3. Then change cifs_enable_signing to
use those instead.

Reported-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-06-27 23:42:18 -05:00
Jeff Layton 3f618223dc move sectype to the cifs_ses instead of TCP_Server_Info
Now that we track what sort of NEGOTIATE response was received, stop
mandating that every session on a socket use the same type of auth.

Push that decision out into the session setup code, and make the sectype
a per-session property. This should allow us to mix multiple sectypes on
a socket as long as they are compatible with the NEGOTIATE response.

With this too, we can now eliminate the ses->secFlg field since that
info is redundant and harder to work with than a securityEnum.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-06-24 01:56:44 -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
Jeff Layton e598d1d8fb cifs: track the flavor of the NEGOTIATE reponse
Track what sort of NEGOTIATE response we get from the server, as that
will govern what sort of authentication types this socket will support.

There are three possibilities:

LANMAN: server sent legacy LANMAN-type response

UNENCAP: server sent a newer-style response, but extended security bit
wasn't set. This socket will only support unencapsulated auth types.

EXTENDED: server sent a newer-style response with the extended security
bit set. This is necessary to support krb5 and ntlmssp auth types.

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 01:56:42 -05:00
Jeff Layton 9193400b69 cifs: factor out check for extended security bit into separate function
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 01:56:42 -05:00
Jeff Layton 9ddec56131 cifs: move handling of signed connections into separate function
Move the sanity checks for signed connections into a separate function.
SMB2's was a cut-and-paste job from CIFS code, so we can make them use
the same function.

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 01:56:41 -05:00
Jeff Layton 2190eca1d0 cifs: break out lanman NEGOTIATE handling into separate function
...this also gets rid of some #ifdef ugliness too.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2013-06-24 01:56:41 -05:00
Jeff Layton 31d9e2bd5f cifs: break out decoding of security blob into separate function
...cleanup.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2013-06-24 01:56:41 -05:00
Jeff Layton 3534b8508e cifs: throw a warning if negotiate or sess_setup ops are passed NULL server or session pointers
These look pretty cargo-culty to me, but let's be certain. Leave
them in place for now. Pop a WARN if it ever does happen. Also,
move to a more standard idiom for setting the "server" pointer.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2013-06-24 01:56:40 -05:00
Jeff Layton 0124cc4511 cifs: store the real expected sequence number in the mid
Currently, the signing routines take a pointer to a place to store the
expected sequence number for the mid response. It then stores a value
that's one below what that sequence number should be, and then adds one
to it when verifying the signature on the response.

Increment the sequence number before storing the value in the mid, and
eliminate the "+1" when checking the signature.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-05-04 22:18:01 -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
Silviu-Mihai Popescu f7f7c1850e fs: cifs: use kmemdup instead of kmalloc + memcpy
This replaces calls to kmalloc followed by memcpy with a single call to
kmemdup. This was found via make coccicheck.

Signed-off-by: Silviu-Mihai Popescu <silviupopescu1990@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-05-04 22:08:19 -05:00
Jeff Layton 94e1800768 cifs: don't try to unlock pagecache page after releasing it
We had a recent fix to fix the release of pagecache pages when
cifs_writev_requeue writes fail. Unfortunately, it releases the page
before trying to unlock it. At that point, the page might be gone by the
time the unlock comes in.

Unlock the page first before checking the value of "rc", and only then
end writeback and release the pages. The page lock isn't required for
any of those operations so this should be safe.

Reported-by: Anton Altaparmakov <aia21@cam.ac.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2013-03-06 19:03:57 -06:00
Ouyang Maochun c51bb0ea40 cifs: bugfix for unreclaimed writeback pages in cifs_writev_requeue()
Pages get the PG_writeback flag set before cifs sends its
request to SMB server in cifs_writepages(), if the SMB service
goes down, cifs may try to recommit the writing requests in
cifs_writev_requeue(). However, it does not clean its PG_writeback
flag and relaimed the pages even if it fails again in
cifs_writev_requeue(), which may lead to the hanging of the
processes accessing the cifs directory. This patch just cleans
the PG_writeback flags and reclaims the pages under that circumstances.

    Steps to reproduce the bug(trying serveral times may trigger the issue):
    1.Write from cifs client continuously.(e.g dd if=/dev/zero of=<cifs file>)
    2.Stop SMB service from server.(e.g service smb stop)
    3.Wait for two minutes, and then start SMB service from
server.(e.g service smb start)
    4.The processes which are accessing cifs directory may hang up.

Signed-off-by: Ouyang Maochun <ouyang.maochun@zte.com.cn>
Signed-off-by: Jiang Yong <jian.yong5@zte.com.cn>
Tested-by: Zhang Xianwei <zhang.xianwei8@zte.com.cn>
Reviewed-by: Wang Liang <wang.liang82@zte.com.cn>
Reviewed-by: Cai Qu <cai.qu@zte.com.cn>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2013-02-28 09:01:47 -06:00
Eric W. Biederman 49418b2c28 cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t
Use INVALID_UID and INVALID_GID instead of NO_CHANGE_64 to indicate
the value should not be changed.

In cifs_fill_unix_set_info convert from kuids and kgids into uids and
gids that will fit in FILE_UNIX_BASIC_INFO.

Cc: Steve French <smfrench@gmail.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-02-13 07:28:49 -08:00
Shirish Pargaonkar c052e2b423 cifs: obtain file access during backup intent lookup (resend)
Rebased and resending the patch.

Path based queries can fail for lack of access, especially during lookup
during open.
open itself would actually succeed becasue of back up intent bit
but queries (either path or file handle based) do not have a means to
specifiy backup intent bit.
So query the file info during lookup using
 trans2 / findfirst / file_id_full_dir_info
to obtain file info as well as file_id/inode value.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-28 15:32:28 -05:00
Jeff Layton 5819575ec6 cifs: replace kvec array in readdata with a single kvec
The array is no longer needed. We just need a single kvec to hold the
header for signature checking.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2012-09-24 21:46:32 -05:00
Jeff Layton 8321fec436 cifs: convert async read code to use pages array without kmapping
Replace the "marshal_iov" function with a "read_into_pages" function.
That function will copy the read data off the socket and into the
pages array, kmapping and reading pages one at a time.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2012-09-24 21:46:32 -05:00
Jeff Layton eddb079deb cifs: convert async write code to pass in data via rq_pages array
Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:31 -05:00
Jeff Layton fec344e3f3 cifs: change cifs_call_async to use smb_rqst structs
For now, none of the callers populate rq_pages. That will be done for
writes in a later patch. While we're at it, change the prototype of
setup_async_request not to need a return pointer argument. Just
return the pointer to the mid_q_entry or an ERR_PTR.

Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:31 -05:00
Jeff Layton bf5ea0e2f2 cifs: change signing routines to deal with smb_rqst structs
We need a way to represent a call to be sent on the wire that does not
require having all of the page data kmapped. Behold the smb_rqst struct.
This new struct represents an array of kvecs immediately followed by an
array of pages.

Convert the signing routines to use these structs under the hood and
turn the existing functions for this into wrappers around that. For now,
we're just changing these functions to take different args. Later, we'll
teach them how to deal with arrays of pages.

Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:30 -05:00
Pavel Shilovsky d143341815 CIFS: Move set_file_size to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:29 -05:00
Steve French d6e906f1b5 CIFS: Move hardlink to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:29 -05:00
Pavel Shilovsky 8ceb984379 CIFS: Move rename to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:28 -05:00
Pavel Shilovsky ba9ad7257a CIFS: Move writepage to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:28 -05:00
Pavel Shilovsky 3331914125 CIFS: Add SMB2 support for cifs_iovec_write
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2012-09-24 21:46:28 -05:00
Pavel Shilovsky c9de5c80d5 CIFS: Move async write to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:28 -05:00
Pavel Shilovsky 09a4707e76 CIFS: Add SMB2 support for cifs_iovec_read
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:27 -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 ed6875e0d6 CIFS: Move unlink code to ops struct
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-09-24 21:46:26 -05:00
Steve French 985e4ff016 cifs: print error code if smb signature verification fails
While trying to debug a SMB signature related issue with Windows Servers
figured out it might be easier to debug if we print the error code from
cifs_verify_signature(). Also, fix indendation while at it.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-08-19 22:30:13 -05:00
Pavel Shilovsky f958ca5d88 CIFS: Move rmdir code to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-27 15:17:47 -05:00
Pavel Shilovsky f436720e94 CIFS: Separate protocol specific part from mkdir
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-27 15:17:40 -05:00
Pavel Shilovsky ff691e9694 CIFS: Simplify cifs_mkdir call
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-27 15:17:16 -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 1208ef1f76 CIFS: Move query inode info code to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:07 +04:00
Pavel Shilovsky 68889f269b CIFS: Move is_path_accessible to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:04 +04:00
Pavel Shilovsky b669f33ca6 CIFS: Move getting dfs referalls to ops struct
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:55:01 +04:00
Pavel Shilovsky aa24d1e969 CIFS: Process reconnects for SMB2 shares
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:54:59 +04:00
Pavel Shilovsky ec2e4523fd CIFS: Add capability to send SMB2 negotiate message
and add negotiate request type to let set_credits know that
we are only on negotiate stage and no need to make a decision
about disabling echos and oplocks.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-24 21:54:55 +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 2e6e02ab6d CIFS: Move protocol specific tcon/tdis code to ops struct
and rename variables around the code changes.

Reviewed-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 10:25:06 -05:00
Pavel Shilovsky 58c45c58a1 CIFS: Move protocol specific session setup/logoff code to ops struct
Reviewed-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 10:25:03 -05:00
Pavel Shilovsky 286170aa24 CIFS: Move protocol specific negotiate code to ops struct
Reviewed-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 00:33:26 -05:00
Pavel Shilovsky a891f0f895 CIFS: Extend credit mechanism to process request type
Split all requests to echos, oplocks and others - each group uses
its own credit slot. This is indicated by new flags

CIFS_ECHO_OP and CIFS_OBREAK_OP

that are not used now for CIFS. This change is required to support
SMB2 protocol because of different processing of these commands.

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 00:32:48 -05:00
Jeff Layton c5fd363d77 cifs: move file_lock off stack in cifs_push_posix_locks
struct file_lock is pretty large, so we really don't want that on the
stack in a potentially long call chain. Reorganize the arguments to
CIFSSMBPosixLock to eliminate the need for that.

Eliminate the get_flag and simply use a non-NULL pLockInfo to indicate
that this is a "get" operation. In order to do that, need to add a new
loff_t argument for the start_offset.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-23 16:36:29 -05:00
Jeff Layton ac3aa2f8ae cifs: remove extraneous newlines from cERROR and cFYI calls
Those macros add a newline on their own, so there's not any need to
embed one in the message itself.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-23 16:36:26 -05:00
Jeff Layton 3cf003c08b cifs: when CONFIG_HIGHMEM is set, serialize the read/write kmaps
Jian found that when he ran fsx on a 32 bit arch with a large wsize the
process and one of the bdi writeback kthreads would sometimes deadlock
with a stack trace like this:

crash> bt
PID: 2789   TASK: f02edaa0  CPU: 3   COMMAND: "fsx"
 #0 [eed63cbc] schedule at c083c5b3
 #1 [eed63d80] kmap_high at c0500ec8
 #2 [eed63db0] cifs_async_writev at f7fabcd7 [cifs]
 #3 [eed63df0] cifs_writepages at f7fb7f5c [cifs]
 #4 [eed63e50] do_writepages at c04f3e32
 #5 [eed63e54] __filemap_fdatawrite_range at c04e152a
 #6 [eed63ea4] filemap_fdatawrite at c04e1b3e
 #7 [eed63eb4] cifs_file_aio_write at f7fa111a [cifs]
 #8 [eed63ecc] do_sync_write at c052d202
 #9 [eed63f74] vfs_write at c052d4ee
#10 [eed63f94] sys_write at c052df4c
#11 [eed63fb0] ia32_sysenter_target at c0409a98
    EAX: 00000004  EBX: 00000003  ECX: abd73b73  EDX: 012a65c6
    DS:  007b      ESI: 012a65c6  ES:  007b      EDI: 00000000
    SS:  007b      ESP: bf8db178  EBP: bf8db1f8  GS:  0033
    CS:  0073      EIP: 40000424  ERR: 00000004  EFLAGS: 00000246

Each task would kmap part of its address array before getting stuck, but
not enough to actually issue the write.

This patch fixes this by serializing the marshal_iov operations for
async reads and writes. The idea here is to ensure that cifs
aggressively tries to populate a request before attempting to fulfill
another one. As soon as all of the pages are kmapped for a request, then
we can unlock and allow another one to proceed.

There's no need to do this serialization on non-CONFIG_HIGHMEM arches
however, so optimize all of this out when CONFIG_HIGHMEM isn't set.

Cc: <stable@vger.kernel.org>
Reported-by: Jian Li <jiali@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2012-07-16 23:57:14 -05:00