deal with d_move() races properly; rename_lock read-retry loop,
rcu_read_lock() held while walking to root, d_lock held over
subtraction from namelen and copying the component to stabilize
->d_name.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

...as that function can sleep.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Regression introduced in commit 724d9f1c.

Prior to that, expand_dfs_referral would regenerate the mount data string
and then call cifs_parse_mount_options to re-parse it (klunky, but it
worked). The above commit moved cifs_parse_mount_options out of cifs_mount,
so the re-parsing of the new mount options no longer occurred. Fix it by
making expand_dfs_referral re-parse the mount options.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

This needs to be done regardless of whether that KConfig option is set
or not.
Reported-by: NSven-Haegar Koch <haegar@sdinet.de>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NPavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Add an FS-Cache helper to bulk uncache pages on an inode.  This will
only work for the circumstance where the pages in the cache correspond
1:1 with the pages attached to an inode's page cache.

This is required for CIFS and NFS: When disabling inode cookie, we were
returning the cookie and setting cifsi->fscache to NULL but failed to
invalidate any previously mapped pages.  This resulted in "Bad page
state" errors and manifested in other kind of errors when running
fsstress.  Fix it by uncaching mapped pages when we disable the inode
cookie.

This patch should fix the following oops and "Bad page state" errors
seen during fsstress testing.

  ------------[ cut here ]------------
  kernel BUG at fs/cachefiles/namei.c:201!
  invalid opcode: 0000 [#1] SMP
  Pid: 5, comm: kworker/u:0 Not tainted 2.6.38.7-30.fc15.x86_64 #1 Bochs Bochs
  RIP: 0010: cachefiles_walk_to_object+0x436/0x745 [cachefiles]
  RSP: 0018:ffff88002ce6dd00  EFLAGS: 00010282
  RAX: ffff88002ef165f0 RBX: ffff88001811f500 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000000000100 RDI: 0000000000000282
  RBP: ffff88002ce6dda0 R08: 0000000000000100 R09: ffffffff81b3a300
  R10: 0000ffff00066c0a R11: 0000000000000003 R12: ffff88002ae54840
  R13: ffff88002ae54840 R14: ffff880029c29c00 R15: ffff88001811f4b0
  FS:  00007f394dd32720(0000) GS:ffff88002ef00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 00007fffcb62ddf8 CR3: 000000001825f000 CR4: 00000000000006e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Process kworker/u:0 (pid: 5, threadinfo ffff88002ce6c000, task ffff88002ce55cc0)
  Stack:
   0000000000000246 ffff88002ce55cc0 ffff88002ce6dd58 ffff88001815dc00
   ffff8800185246c0 ffff88001811f618 ffff880029c29d18 ffff88001811f380
   ffff88002ce6dd50 ffffffff814757e4 ffff88002ce6dda0 ffffffff8106ac56
  Call Trace:
   cachefiles_lookup_object+0x78/0xd4 [cachefiles]
   fscache_lookup_object+0x131/0x16d [fscache]
   fscache_object_work_func+0x1bc/0x669 [fscache]
   process_one_work+0x186/0x298
   worker_thread+0xda/0x15d
   kthread+0x84/0x8c
   kernel_thread_helper+0x4/0x10
  RIP  cachefiles_walk_to_object+0x436/0x745 [cachefiles]
  ---[ end trace 1d481c9af1804caa ]---

I tested the uncaching by the following means:

 (1) Create a big file on my NFS server (104857600 bytes).

 (2) Read the file into the cache with md5sum on the NFS client.  Look in
     /proc/fs/fscache/stats:

	Pages  : mrk=25601 unc=0

 (3) Open the file for read/write ("bash 5<>/warthog/bigfile").  Look in proc
     again:

	Pages  : mrk=25601 unc=25601
Reported-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-and-Tested-by: NSuresh Jayaraman <sjayaraman@suse.de>
cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

...as that makes for a cumbersome interface. Make it take a regular
smb_vol pointer and rely on the caller to zero it out if needed.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NPavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Regression introduced by commit f87d39d9.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NPavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

This call to cifs_cleanup_volume_info is clearly wrong. As soon as it's
called the following call to cifs_get_tcp_session will oops as the
volume_info pointer will then be NULL.

The caller of cifs_mount should clean up this data since it passed it
in. There's no need for us to call this here.

Regression introduced by commit 724d9f1c.
Reported-by: NAdam Williamson <awilliam@redhat.com>
Cc: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Benjamin S. reported that he was unable to suspend his machine while
it had a cifs share mounted. The freezer caused this to spew when he
tried it:

-----------------------[snip]------------------
PM: Syncing filesystems ... done.
Freezing user space processes ... (elapsed 0.01 seconds) done.
Freezing remaining freezable tasks ...
Freezing of tasks failed after 20.01 seconds (1 tasks refusing to freeze, wq_busy=0):
cifsd         S ffff880127f7b1b0     0  1821      2 0x00800000
 ffff880127f7b1b0 0000000000000046 ffff88005fe008a8 ffff8800ffffffff
 ffff880127cee6b0 0000000000011100 ffff880127737fd8 0000000000004000
 ffff880127737fd8 0000000000011100 ffff880127f7b1b0 ffff880127736010
Call Trace:
 [<ffffffff811e85dd>] ? sk_reset_timer+0xf/0x19
 [<ffffffff8122cf3f>] ? tcp_connect+0x43c/0x445
 [<ffffffff8123374e>] ? tcp_v4_connect+0x40d/0x47f
 [<ffffffff8126ce41>] ? schedule_timeout+0x21/0x1ad
 [<ffffffff8126e358>] ? _raw_spin_lock_bh+0x9/0x1f
 [<ffffffff811e81c7>] ? release_sock+0x19/0xef
 [<ffffffff8123e8be>] ? inet_stream_connect+0x14c/0x24a
 [<ffffffff8104485b>] ? autoremove_wake_function+0x0/0x2a
 [<ffffffffa02ccfe2>] ? ipv4_connect+0x39c/0x3b5 [cifs]
 [<ffffffffa02cd7b7>] ? cifs_reconnect+0x1fc/0x28a [cifs]
 [<ffffffffa02cdbdc>] ? cifs_demultiplex_thread+0x397/0xb9f [cifs]
 [<ffffffff81076afc>] ? perf_event_exit_task+0xb9/0x1bf
 [<ffffffffa02cd845>] ? cifs_demultiplex_thread+0x0/0xb9f [cifs]
 [<ffffffffa02cd845>] ? cifs_demultiplex_thread+0x0/0xb9f [cifs]
 [<ffffffff810444a1>] ? kthread+0x7a/0x82
 [<ffffffff81002d14>] ? kernel_thread_helper+0x4/0x10
 [<ffffffff81044427>] ? kthread+0x0/0x82
 [<ffffffff81002d10>] ? kernel_thread_helper+0x0/0x10

Restarting tasks ... done.
-----------------------[snip]------------------

We do attempt to perform a try_to_freeze in cifs_reconnect, but the
connection attempt itself seems to be taking longer than 20s to time
out. The connect timeout is governed by the socket send and receive
timeouts, so we can shorten that period by setting those timeouts
before attempting the connect instead of after.

Adam Williamson tested the patch and said that it seems to have fixed
suspending on his laptop when a cifs share is mounted.
Reported-by: NBenjamin S <da_joind@gmx.net>
Tested-by: NAdam Williamson <awilliam@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

... instead of just failing with -EINVAL
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

if cifs_get_root() fails, we end up with ->mount() returning NULL,
which is not what callers expect.  Moreover, in case of superblock
reuse we end up leaking a superblock reference...
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

have ->s_fs_info set by the set() callback passed to sget()
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

all callers of cifs_umount() proceed to do the same thing; pull it into
cifs_umount() itself.
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

instead of calling it manually in case if cifs_read_super() fails
to set ->s_root, just call it from ->kill_sb().  cifs_put_super()
is gone now *and* we have cifs_sb shutdown and destruction done
after the superblock is gone from ->s_instances.
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... to the point prior to sget().  Now we have cifs_sb set up early
enough.
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

a) superblock argument is unused
b) it always returns 0
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

no need to wait until cifs_read_super() and we need it done
by the time cifs_mount() will be called.
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

pull mountdata allocation up, so that it won't stand in the way when
we lift cifs_mount() to location before sget().
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

cifs_sb and nls end up leaked...
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

To close sget() races we'll need to be able to set cifs_sb up before
we get the superblock, so we'll want to be able to do cifs_mount()
earlier.  Fortunately, it's easy to do - setting ->s_maxbytes can
be done in cifs_read_super(), ditto for ->s_time_gran and as for
putting MS_POSIXACL into ->s_flags, we can mirror it in ->mnt_cifs_flags
until cifs_read_super() is called.  Kill unused 'devname' argument,
while we are at it...
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

if cifs_sb allocation fails, we still need to drop nls we'd stashed
into volume_info - the one we would've copied to cifs_sb if we could
allocate the latter.
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

if we get to out_super with ->s_root already set (e.g. with
cifs_get_root() failure), we'll end up with cifs_put_super()
called and ->mountdata freed twice.  We'll also get cifs_sb
freed twice and cifs_sb->local_nls dropped twice.  The problem
is, we can get to out_super both with and without ->s_root,
which makes ->put_super() a bad place for such work.

Switch to ->kill_sb(), have all that work done there after
kill_anon_super().  Unlike ->put_super(), ->kill_sb() is
called by deactivate_locked_super() whether we have ->s_root
or not.
Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Acked-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

This is currently leaked in the rc == 0 case.
Reported-by: NJ. Bruce Fields <bfields@fieldses.org>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Hopefully last version. Base signing check on CAP_UNIX instead of
tcon->unix_ext, also clean up the comments a bit more.

According to Hongwei Sun's blog posting here:

    http://blogs.msdn.com/b/openspecification/archive/2009/04/10/smb-maximum-transmit-buffer-size-and-performance-tuning.aspx

CAP_LARGE_WRITEX is ignored when signing is active. Also, the maximum
size for a write without CAP_LARGE_WRITEX should be the maxBuf that
the server sent in the NEGOTIATE request.

Fix the wsize negotiation to take this into account. While we're at it,
alter the other wsize definitions to use sizeof(WRITE_REQ) to allow for
slightly larger amounts of data to potentially be written per request.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Figured it out: it was broken by b946845a commit - "cifs: cifs_parse_mount_options: do not tokenize mount options in-place". So, as a quick fix I suggest to apply this patch.

[PATCH] CIFS: Fix kfree() with constant string in a null user case
Signed-off-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

nothing potentially blocking except generic_permission(), which
will DTRT
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

... for uniformity and cleaner debug logs.
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Long ago (in commit 00e485b0), I added some code to handle share-level
passwords in CIFSTCon. That code ignored the fact that it's legit to
pass in a NULL tcon pointer when connecting to the IPC$ share on the
server.

This wasn't really a problem until recently as we only called CIFSTCon
this way when the server returned -EREMOTE. With the introduction of
commit c1508ca2 however, it gets called this way on every mount, causing
an oops when share-level security is in effect.

Fix this by simply treating a NULL tcon pointer as if user-level
security were in effect. I'm not aware of any servers that protect the
IPC$ share with a specific password anyway. Also, add a comment to the
top of CIFSTCon to ensure that we don't make the same mistake again.

Cc: <stable@kernel.org>
Reported-by: NMartijn Uffing <mp3project@sarijopen.student.utwente.nl>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

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

It's possible for the following set of events to happen:

cifsd calls cifs_reconnect which reconnects the socket. A userspace
process then calls cifs_negotiate_protocol to handle the NEGOTIATE and
gets a reply. But, while processing the reply, cifsd calls
cifs_reconnect again.  Eventually the GlobalMid_Lock is dropped and the
reply from the earlier NEGOTIATE completes and the tcpStatus is set to
CifsGood. cifs_reconnect then goes through and closes the socket and sets the
pointer to zero, but because the status is now CifsGood, the new socket
is not created and cifs_reconnect exits with the socket pointer set to
NULL.

Fix this by only setting the tcpStatus to CifsGood if the tcpStatus is
CifsNeedNegotiate, and by making sure that generic_ip_connect is always
called at least once in cifs_reconnect.

Note that this is not a perfect fix for this issue. It's still possible
that the NEGOTIATE reply is handled after the socket has been closed and
reconnected. In that case, the socket state will look correct but it no
NEGOTIATE was performed on it be for the wrong socket. In that situation
though the server should just shut down the socket on the next attempted
send, rather than causing the oops that occurs today.

Cc: <stable@kernel.org> # .38.x: fd88ce93: [CIFS] cifs: clarify the meaning of tcpStatus == CifsGood
Reported-and-Tested-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

cifs_sb_master_tlink was declared as inline, but without a definition.
Remove the declaration and move the definition up.
Signed-off-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

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

When signing is enabled, the first session that's established on a
socket will cause a printk like this to pop:

    CIFS VFS: Unexpected SMB signature

This is because the key exchange hasn't happened yet, so the signature
field is bogus. Don't try to check the signature on the socket until the
first session has been established. Also, eliminate the specific check
for SMB_COM_NEGOTIATE since this check covers that case too.

Cc: stable@kernel.org
Cc: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Build fails if CONFIG_KEYS is not selected.
Signed-off-by: NDarren Salt <linux@youmustbejoking.demon.co.uk>
Reviewed-by: NShirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

error path after mountdata check frees uninitialized mountdata_copy
Signed-off-by: NVasily Averin <vvs@sw.ru>
Signed-off-by: NSteve French <sfrench@us.ibm.com>