When kernel_recvmsg returns -EAGAIN or -ERESTARTSYS, then
cifs_demultiplex_thread sleeps for a bit and then tries the read again.
When it does this, it's not zeroing out the length and that throws off
the value of total_read. Fix it to zero out the length.

Can cause memory corruption:
If kernel_recvmsg returns an error and total_read is a large enough
value, then we'll end up going through the loop again. total_read will
be a bogus value, as will (pdu_length-total_read). When this happens we
end up calling kernel_recvmsg with a bogus value (possibly larger than
the current iov_len).

At that point, memcpy_toiovec can overrun iov. It will start walking
up the stack, casting other things that are there to struct iovecs
(since it assumes that it's been passed an array of them). Any pointer
on the stack at an address above the kvec is a candidate for corruption
here.

Many thanks to Ulrich Obergfell for pointing this out.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NCyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NShirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Also fixes typo which could cause build break
Signed-off-by: NSteve French <sfrench@us.ibm.com>

We were allocating request buffers twice in the statfs
path when mounted to very old (Windows 9x) servers.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

On a mount without posix extensions enabled, when an unlock request is
made, the client can release more than is intended. To reproduce, on a
CIFS mount without posix extensions enabled:

1) open file
2) do fcntl lock: start=0 len=1
3) do fcntl lock: start=2 len=1
4) do fcntl unlock: start=0 len=1

...on the unlock call the client sends an unlock request to the server
for both locks. The problem is a bad test in cifs_lock.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Caused by unneeded reopen during reconnect while spinlock held.

Fixes kernel bugzilla bug #7903

Thanks to Lin Feng Shen for testing this, and Amit Arora for
some nice problem determination to narrow this down.
Acked-by: NDave Kleikamp <shaggy@us.ibm.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

In the cleanup phase of the dbench test, we were noticing sharing
violation followed by failed directory removals when dbench
did not close the test files before the cleanup phase started.
Using the new POSIX unlink, which Samba has supported for a few
months, avoids this.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

nfsd is passing null nameidata (probably the only one doing that)
on call to create - cifs was missing one check for this.

Note that running nfsd over a cifs mount requires specifying fsid on
the nfs exports entry and requires mounting cifs with serverino mount
option.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NYehuda Sadeh Weinraub <Yehuda.Sadeh@expand.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Currently, if mount with a signing-enabled sec= option (e.g.
sec=ntlmi), the kernel does a warning printk if the server doesn't
support signing, and then proceeds without signatures.

This is probably OK for people that think to look at the ring buffer,
but seems wrong to me. If someone explicitly requests signing, we
should error out if that request can't be satisfied. They can then
reattempt the mount without signing if that's ok.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

We had a customer report that attempting to make CIFS mount with a null
username (i.e. doing an anonymous mount) doesn't work. Looking through the
code, it looks like CIFS expects a NULL username from userspace in order
to trigger an anonymous mount. The mount.cifs code doesn't seem to ever
pass a null username to the kernel, however.

It looks also like the kernel can take a sec=none option, but it only seems
to look at it if the username is already NULL. This seems redundant and
effectively makes sec=none useless.

The following patch makes sec=none force an anonymous mount.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

When CIFS Unix Extensions are negotiated we get the Unix uid and gid
owners of the file from the server (on the Unix Query Path Info
levels), but if the server's uids don't match the client uid's users
were having to disable the Unix Extensions (which turned off features
they still wanted).   The changeset patch allows users to override uid
and/or gid for file/directory owner with a default uid and/or gid
specified at mount (as is often done when mounting from Linux cifs
client to Windows server).  This changeset also displays the uid
and gid used by default in /proc/mounts (if applicable).

Also cleans up code by adding some of the missing spaces after
"if" keywords per-kernel style guidelines (as suggested by Randy Dunlap
when he reviewed the patch).
Signed-off-by: NSteve French <sfrench@us.ibm.com>

IPv6 support was started a few years ago in the cifs client, but lacked a
kernel helper function for parsing the ascii form of the ipv6 address. Now
that that is added (and now IPv6 is the default that some OS use now) it
was fairly easy to finish  the cifs ipv6 support.  This  requires that
CIFS_EXPERIMENTAL be enabled and (at least until the mount.cifs module is
modified to use a new ipv6 friendly call instead of gethostbyname) and the
ipv6 address be passed on the mount as "ip=" mount option.

Thanks
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

Remove read only dos attribute on chmod when adding any write permission (ie on any of
user/group/other (not all of user/group/other ie  0222) when
mounted to windows.

Suggested by: Urs Fleisch
Signed-off-by: NUrs Fleisch <urs.fleisch@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

When a file had a dos attribute of 0x1 (readonly - but dos attribute
of archive was not set) - doing chmod 0777 or equivalent would
try to set a dos attribute of 0 (which some servers ignore)
rather than ATTR_NORMAL (0x20) which most servers accept.
Does not affect servers which support the CIFS Unix Extensions.
Acked-by: NPrasad Potluri <pvp@us.ibm.com>
Acked-by: NShirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NAlan Tyso <atyson@hp.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Noticed by Shaggy.
Signed-off-by: NShaggy <shaggy@us.ibm.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Could cause hangs on smp systems in i_size_read on a cifs inode
whose size has been previously simultaneously updated from
different processes.

Thanks to Brian Wang for some great testing/debugging on this
hard problem.

Fixes kernel bugzilla #7903

CC: Shirish Pargoankar <shirishp@us.ibm.com>
CC: Shaggy <shaggy@us.ibm.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

After temporary server or network failure and reconneciton, we were not
resending the unix capabilities via SetFSInfo - which confused Samba posix
byte range locking code.

Discovered by jra
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

Missing tab.  Missing entry in changelog
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

Windows servers are pickier about NTLMv2 than Samba.
This enables more secure mounts to Windows (not just Samba)
ie when "sec=ntlmv2" is specified on the mount.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Fixes Samba bugzilla bug # 4182

Rename by handle failures (retry after rename by path) were not
being returned back.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Some servers are configured to only allow null user mounts for
guest access.  Allow nul user (anonymous) mounts e.g.
	mount -t cifs //server/share /mnt -o username=
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Samba bugzilla #4040
Signed-off-by: NSteve French <sfrench@us.ibm.com>

specified

Pointed out by Bjoern Jacke
Signed-off-by: NSteve French <sfrench@us.ibm.com>

new POSIX locking code
Signed-off-by: NSteve French <sfrench@us.ibm.com>

request and do not time out slow requests to a server that is still responding
well to other threads

Suggested by jra of Samba team
Signed-off-by: NSteve French <sfrench@us.ibm.com>
(cherry picked from 89b57148115479eef074b8d3f86c4c86c96ac969 commit)

longer user and domain names and allow passing sec options on mount
Signed-off-by: NSteve French <sfrench@us.ibm.com>

NTLMv2 authentication (stronger authentication than default NTLM) which
many servers support now works.  There was a problem with the construction
of the security blob in the older code.  Currently requires
	/proc/fs/cifs/Experimental to be set to 2
and
	/proc/fs/cifs/SecurityFlags to be set to 0x4004 (to require using
	NTLMv2 instead of default of NTLM)

Next we will check signing to make sure optional NTLMv2 packet signing also
works.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Fixes oops to OS/2 on ls and removes redundant NTCreateX calls to servers
which do not support NT SMBs.  Key operations to OS/2 work.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

during mount. Especially important for some non-Western languages.
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NSteve French <sfrench@us.ibm.com>

in directory

Also includes first part of fix to compensate for servers which forget
to return . and .. as well as updates to changelog and cifs readme.
Signed-off-by: NSteve French <sfrench@us.ibm.com>