Commit Graph

199 Commits

Author SHA1 Message Date
Steve French
9e39b0ae8a [CIFS] Remove unneeded QuerySymlink call and fix mapping for unmapped status
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-30 21:31:15 +00:00
Steve French
d185cda771 [CIFS] rename cifs_strndup to cifs_strndup_from_ucs
In most cases, cifs_strndup is converting from Unicode (UCS2 / UTF-32) to
the configured local code page for the Linux mount (usually UTF8), so
Jeff suggested that to make it more clear that cifs_strndup is doing
a conversion not just memory allocation and copy, rename the function
to including "from_ucs" (ie Unicode)

Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-30 17:45:10 +00:00
Igor Mammedov
5c2503a8e3 Added loop check when mounting DFS tree.
Added loop check when mounting DFS tree. mount will fail with
ELOOP if referral walks exceed MAX_NESTED_LINK count.

Signed-off-by: Igor Mammedov <niallain@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-30 17:24:09 +00:00
Steve French
20418acd68 [CIFS] Remove older session setup implementation
Two years ago, when the session setup code in cifs was rewritten and moved
to fs/cifs/sess.c, we were asked to keep the old code for a release or so
(which could be reenabled at runtime) since it was such a large change and
because the asn (SPNEGO) and NTLMSSP code was not rewritten and needed to
be. This was useful to avoid regressions, but is long overdue to be removed.
Now that the Kerberos (asn/spnego) code is working in fs/cifs/sess.c,
and the NTLMSSP code moved (NTLMSSP blob setup be rewritten with the
next patch in this series) quite a bit of dead code from fs/cifs/connect.c
now can be removed.

This old code should have been removed last year, but the earlier krb5
patches did not move/remove the NTLMSSP code which we had asked to
be done first.  Since no one else volunteered, I am doing it now.

It is extremely important that we continue to examine the documentation
for this area, to make sure our code continues to be uptodate with
changes since Windows 2003.

Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-30 16:13:32 +00:00
Jeff Layton
cc20c031bb cifs: convert CIFSTCon to use new unicode helper functions
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-30 15:45:00 +00:00
Jeff Layton
22c9d52bc0 cifs: remove unneeded bcc_ptr update in CIFSTCon
This pointer isn't used again after this point. It's also not updated in
the ascii case, so there's no need to update it here.

Pointed-out-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-17 01:26:50 +00:00
Jeff Layton
313fecfa69 cifs: add cFYI messages with some of the saved strings from ssetup/tcon
...to make it easier to find problems in this area in the future.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-17 01:26:50 +00:00
Jeff Layton
f083def68f cifs: fix buffer size for tcon->nativeFileSystem field
The buffer for this was resized recently to fix a bug. It's still
possible however that a malicious server could overflow this field
by sending characters in it that are >2 bytes in the local charset.
Double the size of the buffer to account for this possibility.

Also get rid of some really strange and seemingly pointless NULL
termination. It's NULL terminating the string in the source buffer,
but by the time that happens, we've already copied the string.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-17 01:26:50 +00:00
Steve French
2d6d589d80 [CIFS] remove some build warnings
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-17 01:26:49 +00:00
Steve French
d036f50fc2 [CIFS] Fix build break from recent DFS patch when DFS support not enabled
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-17 01:26:48 +00:00
Igor Mammedov
1bfe73c258 Remote DFS root support.
Allows to mount share on a server that returns -EREMOTE
 at the tree connect stage or at the check on a full path
 accessibility.

Signed-off-by: Igor Mammedov <niallain@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-17 01:26:48 +00:00
Wei Yongjun
74496d365a cifs: remove some pointless conditionals before kfree()
Remove some pointless conditionals before kfree().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-17 01:26:48 +00:00
Steve French
b363b3304b [CIFS] Fix memory overwrite when saving nativeFileSystem field during mount
CIFS can allocate a few bytes to little for the nativeFileSystem field
during tree connect response processing during mount.  This can result
in a "Redzone overwritten" message to be logged.

Signed-off-by: Sridhar Vinay <vinaysridhar@in.ibm.com>
Acked-by: Shirish Pargaonkar <shirishp@us.ibm.com>
CC: Stable <stable@kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-03-18 05:57:22 +00:00
Steve French
4717bed680 [CIFS] fix build error
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-03-12 01:36:20 +00:00
Steve French
be652445fd [CIFS] Add new nostrictsync cifs mount option to avoid slow SMB flush
If this mount option is set, when an application does an
fsync call then the cifs client does not send an SMB Flush
to the server (to force the server to write all dirty data
for this file immediately to disk), although cifs still sends
all dirty (cached) file data to the server and waits for the
server to respond to the write write.  Since SMB Flush can be
very slow, and some servers may be reliable enough (to risk
delaying slightly flushing the data to disk on the server),
turning on this option may be useful to improve performance for
applications that fsync too much, at a small risk of server
crash.  If this mount option is not set, by default cifs will
send an SMB flush request (and wait for a response) on every
fsync call.

Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-03-12 01:36:20 +00:00
Igor Mammedov
e4cce94c9c [CIFS] Prevent OOPs when mounting with remote prefixpath.
Fixes OOPs with message 'kernel BUG at fs/cifs/cifs_dfs_ref.c:274!'.
Checks if the prefixpath in an accesible while we are still in cifs_mount
and fails with reporting a error if we can't access the prefixpath

Should fix Samba bugs 6086 and 5861 and kernel bug 12192

Signed-off-by: Igor Mammedov <niallain@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-02-21 03:36:21 +00:00
Steve French
0e2bedaa39 [CIFS] ipv6_addr_equal for address comparison
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-01-30 21:24:41 +00:00
Jeff Layton
a9ac49d303 cifs: make sure we allocate enough storage for socket address
The sockaddr declared on the stack in cifs_get_tcp_session is too small
for IPv6 addresses. Change it from "struct sockaddr" to "struct
sockaddr_storage" to prevent stack corruption when IPv6 is used.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-01-29 03:32:13 +00:00
Steve French
da505c386c [CIFS] Make socket retry timeouts consistent between blocking and nonblocking cases
We have used approximately 15 second timeouts on nonblocking sends in the past, and
also 15 second SMB timeout (waiting for server responses, for most request types).
Now that we can do blocking tcp sends,
make blocking send timeout approximately the same (15 seconds).

Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-01-29 03:32:13 +00:00
Jeff Layton
0496e02d87 cifs: turn smb_send into a wrapper around smb_sendv
cifs: turn smb_send into a wrapper around smb_sendv

Rename smb_send2 to smb_sendv to make it consistent with kernel naming
conventions for functions that take a vector.

There's no need to have 2 functions to handle sending SMB calls. Turn
smb_send into a wrapper around smb_sendv. This also allows us to
properly mark the socket as needing to be reconnected when there's a
partial send from smb_send.

Also, in practice we always use the address and noblocksnd flag
that's attached to the TCP_Server_Info. There's no need to pass
them in as separate args to smb_sendv.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-01-29 03:32:12 +00:00
Linus Torvalds
0191b625ca Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1429 commits)
  net: Allow dependancies of FDDI & Tokenring to be modular.
  igb: Fix build warning when DCA is disabled.
  net: Fix warning fallout from recent NAPI interface changes.
  gro: Fix potential use after free
  sfc: If AN is enabled, always read speed/duplex from the AN advertising bits
  sfc: When disabling the NIC, close the device rather than unregistering it
  sfc: SFT9001: Add cable diagnostics
  sfc: Add support for multiple PHY self-tests
  sfc: Merge top-level functions for self-tests
  sfc: Clean up PHY mode management in loopback self-test
  sfc: Fix unreliable link detection in some loopback modes
  sfc: Generate unique names for per-NIC workqueues
  802.3ad: use standard ethhdr instead of ad_header
  802.3ad: generalize out mac address initializer
  802.3ad: initialize ports LACPDU from const initializer
  802.3ad: remove typedef around ad_system
  802.3ad: turn ports is_individual into a bool
  802.3ad: turn ports is_enabled into a bool
  802.3ad: make ntt bool
  ixgbe: Fix set_ringparam in ixgbe to use the same memory pools.
  ...

Fixed trivial IPv4/6 address printing conflicts in fs/cifs/connect.c due
to the conversion to %pI (in this networking merge) and the addition of
doing IPv6 addresses (from the earlier merge of CIFS).
2008-12-28 12:49:40 -08:00
Linus Torvalds
54a696bd07 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: (31 commits)
  [CIFS] Remove redundant test
  [CIFS] make sure that DFS pathnames are properly formed
  Remove an already-checked error condition in SendReceiveBlockingLock
  Streamline SendReceiveBlockingLock: Use "goto out:" in an error condition
  Streamline SendReceiveBlockingLock: Use "goto out:" in an error condition
  [CIFS] Streamline SendReceive[2] by using "goto out:" in an error condition
  Slightly streamline SendReceive[2]
  Check the return value of cifs_sign_smb[2]
  [CIFS] Cleanup: Move the check for too large R/W requests
  [CIFS] Slightly simplify wait_for_free_request(), remove an unnecessary "else" branch
  Simplify allocate_mid() slightly: Remove some unnecessary "else" branches
  [CIFS] In SendReceive, move consistency check out of the mutexed region
  cifs: store password in tcon
  cifs: have calc_lanman_hash take more granular args
  cifs: zero out session password before freeing it
  cifs: fix wait_for_response to time out sleeping processes correctly
  [CIFS] Can not mount with prefixpath if root directory of share is inaccessible
  [CIFS] various minor cleanups pointed out by checkpatch script
  [CIFS] fix typo
  [CIFS] remove sparse warning
  ...

Fix trivial conflict in fs/cifs/cifs_fs_sb.h due to comment changes for
the CIFS_MOUNT_xyz bit definitions between cifs updates and security
updates.
2008-12-28 12:37:14 -08:00
Jeff Layton
00e485b019 cifs: store password in tcon
cifs: store password in tcon

Each tcon has its own password for share-level security. Store it in
the tcon and wipe it clean and free it when freeing the tcon. When
doing the tree connect with share-level security, use the tcon password
instead of the session password.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:11 +00:00
Jeff Layton
4e53a3fb98 cifs: have calc_lanman_hash take more granular args
cifs: have calc_lanman_hash take more granular args

We need to use this routine to encrypt passwords associated with the
tcon too. Don't assume that the password will be attached to the
smb_session.

Also, make some of the values in the lower encryption functions
const since they aren't changed.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:11 +00:00
Steve French
61e7480158 [CIFS] various minor cleanups pointed out by checkpatch script
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:10 +00:00
Steve French
13a6e42af8 [CIFS] add mount option to send mandatory rather than advisory locks
Some applications/subsystems require mandatory byte range locks
(as is used for Windows/DOS/OS2 etc). Sending advisory (posix style)
byte range lock requests (instead of mandatory byte range locks) can
lead to problems for these applications (which expect that other
clients be prevented from writing to portions of the file which
they have locked and are updating).  This mount option allows
mounting cifs with the new mount option "forcemand" (or
"forcemandatorylock") in order to have the cifs client use mandatory
byte range locks (ie SMB/CIFS/Windows/NTFS style locks) rather than
posix byte range lock requests, even if the server would support
posix byte range lock requests.  This has no effect if the server
does not support the CIFS Unix Extensions (since posix style locks
require support for the CIFS Unix Extensions), but for mounts
to Samba servers this can be helpful for Wine and applications
that require mandatory byte range locks.

Acked-by: Jeff Layton <jlayton@redhat.com>
CC: Alexander Bokovoy <ab@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:10 +00:00
Jeff Layton
d5c5605c27 cifs: make ipv6_connect take a TCP_Server_Info arg
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:10 +00:00
Jeff Layton
bcf4b1063d cifs: make ipv4_connect take a TCP_Server_Info arg
In order to unify the smb_send routines, we need to reorganize the
routines that connect the sockets. Have ipv4_connect take a
TCP_Server_Info pointer and get the necessary fields from that.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:10 +00:00
Jeff Layton
7586b76585 cifs: don't declare smb_vol info on the stack
struct smb_vol is fairly large, it's probably best to kzalloc it...

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:10 +00:00
Jeff Layton
63c038c297 cifs: move allocation of new TCP_Server_Info into separate function
Clean up cifs_mount a bit by moving the code that creates new TCP
sessions into a separate function. Have that function search for an
existing socket and then create a new one if one isn't found.

Also reorganize the initializion of TCP_Server_Info a bit to prepare
for cleanup of the socket connection code.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:10 +00:00
Jeff Layton
8ecaf67a8e cifs: account for IPv6 in ses->serverName and clean up netbios name handling
The current code for setting the session serverName is IPv4-specific.
Allow it to be an IPv6 address as well. Use NIP* macros to set the
format.

This also entails increasing the length of the serverName field, so
declare a new macro for RFC1001 name length and use it in the
appropriate places.

Finally, drop the unicode_server_Name field from TCP_Server_Info since
it's not used. We can add it back later if needed, but for now it just
wastes memory.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:09 +00:00
Jeff Layton
72ca545b2d cifs: convert tcpSem to a mutex
Mutexes are preferred for single-holder semaphores...

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:09 +00:00
Jeff Layton
0468a2cf91 cifs: take module reference when starting cifsd
cifsd can outlive the last cifs mount. We need to hold a module
reference until it exits to prevent someone from unplugging
the module until we're ready.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-12-26 02:29:09 +00:00
David S. Miller
198d6ba4d7 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/isdn/i4l/isdn_net.c
	fs/cifs/connect.c
2008-11-18 23:38:23 -08:00
James Morris
f3a5c54701 Merge branch 'master' into next
Conflicts:
	fs/cifs/misc.c

Merge to resolve above, per the patch below.

Signed-off-by: James Morris <jmorris@namei.org>

diff --cc fs/cifs/misc.c
index ec36410,addd1dc..0000000
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@@ -347,13 -338,13 +338,13 @@@ header_assemble(struct smb_hdr *buffer
  		/*  BB Add support for establishing new tCon and SMB Session  */
  		/*      with userid/password pairs found on the smb session   */
  		/*	for other target tcp/ip addresses 		BB    */
 -				if (current->fsuid != treeCon->ses->linux_uid) {
 +				if (current_fsuid() != treeCon->ses->linux_uid) {
  					cFYI(1, ("Multiuser mode and UID "
  						 "did not match tcon uid"));
- 					read_lock(&GlobalSMBSeslock);
- 					list_for_each(temp_item, &GlobalSMBSessionList) {
- 						ses = list_entry(temp_item, struct cifsSesInfo, cifsSessionList);
+ 					read_lock(&cifs_tcp_ses_lock);
+ 					list_for_each(temp_item, &treeCon->ses->server->smb_ses_list) {
+ 						ses = list_entry(temp_item, struct cifsSesInfo, smb_ses_list);
 -						if (ses->linux_uid == current->fsuid) {
 +						if (ses->linux_uid == current_fsuid()) {
  							if (ses->server == treeCon->ses->server) {
  								cFYI(1, ("found matching uid substitute right smb_uid"));
  								buffer->Uid = ses->Suid;
2008-11-18 18:52:37 +11:00
Steve French
ab3f992983 [CIFS] Fix check for tcon seal setting and fix oops on failed mount from earlier patch
set tcon->ses earlier

If the inital tree connect fails, we'll end up calling cifs_put_smb_ses
with a NULL pointer. Fix it by setting the tcon->ses earlier.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-11-17 16:03:00 +00:00
Jeff Layton
f1987b44f6 cifs: reinstate sharing of tree connections
Use a similar approach to the SMB session sharing. Add a list of tcons
attached to each SMB session. Move the refcount to non-atomic. Protect
all of the above with the cifs_tcp_ses_lock. Add functions to
properly find and put references to the tcons.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-11-17 03:14:12 +00:00
Steve French
d82c2df54e [CIFS] minor cleanup to cifs_mount
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-11-15 00:07:26 +00:00
Jeff Layton
14fbf50d69 cifs: reinstate sharing of SMB sessions sans races
We do this by abandoning the global list of SMB sessions and instead
moving to a per-server list. This entails adding a new list head to the
TCP_Server_Info struct. The refcounting for the cifsSesInfo is moved to
a non-atomic variable. We have to protect it by a lock anyway, so there's
no benefit to making it an atomic. The list and refcount are protected
by the global cifs_tcp_ses_lock.

The patch also adds a new routines to find and put SMB sessions and
that properly take and put references under the lock.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-11-14 23:56:55 +00:00
Jeff Layton
e7ddee9037 cifs: disable sharing session and tcon and add new TCP sharing code
The code that allows these structs to be shared is extremely racy.
Disable the sharing of SMB and tcon structs for now until we can
come up with a way to do this that's race free.

We want to continue to share TCP sessions, however since they are
required for multiuser mounts. For that, implement a new (hopefully
race-free) scheme. Add a new global list of TCP sessions, and take
care to get a reference to it whenever we're dealing with one.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-11-14 23:42:32 +00:00
Steve French
3ec332ef7a [CIFS] clean up server protocol handling
We're currently declaring both a sockaddr_in and sockaddr6_in on the
stack, but we really only need storage for one of them. Declare a
sockaddr struct and cast it to the proper type. Also, eliminate the
protocolType field in the TCP_Server_Info struct. It's redundant since
we have a sa_family field in the sockaddr anyway.

We may need to revisit this if SCTP is ever implemented, but for now
this will simplify the code.

CIFS over IPv6 also has a number of problems currently. This fixes all
of them that I found. Eventually, it would be nice to move more of the
code to be protocol independent, but this is a start.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-11-14 03:35:10 +00:00
David Howells
a001e5b558 CRED: Wrap task credential accesses in the CIFS filesystem
Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Steve French <sfrench@samba.org>
Cc: linux-cifs-client@lists.samba.org
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:38:47 +11:00
Steve French
3b79521093 [CIFS] Fix cifs reconnection flags
In preparation for Jeff's big umount/mount fixes to remove the possibility of
various races in cifs mount and linked list handling of sessions, sockets and
tree connections, this patch cleans up some repetitive code in cifs_mount,
and addresses a problem with ses->status and tcon->tidStatus in which we
were overloading the "need_reconnect" state with other status in that
field.  So the "need_reconnect" flag has been broken out from those
two state fields (need reconnect was not mutually exclusive from some of the
other possible tid and ses states).  In addition, a few exit cases in
cifs_mount were cleaned up, and a problem with a tcon flag (for lease support)
was not being set consistently for the 2nd mount of the same share

CC: Jeff Layton <jlayton@redhat.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-11-13 19:45:32 +00:00
David S. Miller
9eeda9abd1 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/wireless/ath5k/base.c
	net/8021q/vlan_core.c
2008-11-06 22:43:03 -08:00
Steve French
c527c8a7ff [CIFS] Can't rely on iov length and base when kernel_recvmsg returns error
When retrying kernel_recvmsg, reset iov_base and iov_len.

Note comment from Sridhar: "In the normal path, iov.iov_len is clearly set to 4. But i think you are
running into a case where kernel_recvmsg() is called via 'goto incomplete_rcv'
It happens if the previous call fails with EAGAIN.
If you want to call recvmsg() after EAGAIN failure, you need to reset iov."

Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-11-03 20:46:21 +00:00
Harvey Harrison
be85940548 fs: replace NIPQUAD()
Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u
can be replaced with %pI4

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-31 00:56:28 -07:00
Steve French
edf1ae4038 [CIFS] Reduce number of socket retries in large write path
CIFS in some heavy stress conditions cifs could get EAGAIN
repeatedly in smb_send2 which led to repeated retries and eventually
failure of large writes which could lead to data corruption.

There are three changes that were suggested by various network
developers:

1) convert cifs from non-blocking to blocking tcp sendmsg
(we left in the retry on failure)
2) change cifs to not set sendbuf and rcvbuf size for the socket
(let tcp autotune the buffer sizes since that works much better
in the TCP stack now)
3) if we have a partial frame sent in smb_send2, mark the tcp
session as invalid (close the socket and reconnect) so we do
not corrupt the remaining part of the SMB with the beginning
of the next SMB.

This does not appear to hurt performance measurably and has
been run in various scenarios, but it definately removes
a corruption that we were seeing in some high stress
test cases.

Acked-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-10-29 00:47:57 +00:00
Jeff Layton
b1c8d2b421 cifs: handle the TCP_Server_Info->tsk field more carefully
cifs: handle the TCP_Server_Info->tsk field more carefully

We currently handle the TCP_Server_Info->tsk field without any locking,
but with some half-measures to try and prevent races. These aren't
really sufficient though. When taking down cifsd, use xchg() to swap
the contents of the tsk field with NULL so we don't end up trying
to send it more than one signal. Also, don't allow cifsd to exit until
the signal is received if we expect one.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-10-23 05:06:20 +00:00
Steve French
84210e9120 [CIFS] improve setlease handling
fcntl(F_SETLEASE) currently is not exported by cifs (nor by local file
systems) so cifs grants leases based on how other local processes have
opened the file not by whether the file is cacheable (oplocked).  This
adds the check to make sure that the file is cacheable on the client
before checking whether we can grant the lease locally
(generic_setlease).  It also adds a mount option for cifs (locallease)
if the user wants to override this and try to grant leases even
if the server did not grant oplock.

Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-10-23 04:42:37 +00:00
Jeff Layton
469ee614aa [CIFS] eliminate usage of kthread_stop for cifsd
When cifs_demultiplex_thread was converted to a kthread based kernel
thread, great pains were taken to make it so that kthread_stop would be
used to bring it down. This just added unnecessary complexity since we
needed to use a signal anyway to break out of kernel_recvmsg.

Also, cifs_demultiplex_thread does a bit of cleanup as it's exiting, and
we need to be certain that this gets done. It's possible for a kthread
to exit before its main function is ever run if kthread_stop is called
soon after its creation. While I'm not sure that this is a real problem
with cifsd now, it could be at some point in the future if cifs_mount is
ever changed to bring down the thread quickly.

The upshot here is that using kthread_stop to bring down the thread just
adds extra complexity with no real benefit. This patch changes the code
to use the original method to bring down the thread, but still leaves it
so that the thread is actually started with kthread_run.

This seems to fix the deadlock caused by the reproducer in this bug
report:

https://bugzilla.samba.org/show_bug.cgi?id=5720

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2008-10-16 18:46:39 +00:00