It's the essential step before respecting MaxMpxCount value during
negotiating because we will keep only one extra slot for sending
echo requests. If there is no response during two echo intervals -
reconnect the tcp session.
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Some servers sets this value less than 50 that was hardcoded and
we lost the connection if when we exceed this limit. Fix this by
respecting this value - not sending more than the server allows.

Cc: stable@kernel.org
Reviewed-by: NJeff Layton <jlayton@samba.org>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <stevef@smf-gateway.(none)>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The i_mutex lock use of generic _file_llseek hurts.  Independent processes
accessing the same file synchronize over a single lock, even though
they have no need for synchronization at all.

Under high utilization this can cause llseek to scale very poorly on larger
systems.

This patch does some rethinking of the llseek locking model:

First the 64bit f_pos is not necessarily atomic without locks
on 32bit systems. This can already cause races with read() today.
This was discussed on linux-kernel in the past and deemed acceptable.
The patch does not change that.

Let's look at the different seek variants:

SEEK_SET: Doesn't really need any locking.
If there's a race one writer wins, the other loses.

For 32bit the non atomic update races against read()
stay the same. Without a lock they can also happen
against write() now.  The read() race was deemed
acceptable in past discussions, and I think if it's
ok for read it's ok for write too.

=> Don't need a lock.

SEEK_END: This behaves like SEEK_SET plus it reads
the maximum size too. Reading the maximum size would have the
32bit atomic problem. But luckily we already have a way to read
the maximum size without locking (i_size_read), so we
can just use that instead.

Without i_mutex there is no synchronization with write() anymore,
however since the write() update is atomic on 64bit it just behaves
like another racy SEEK_SET.  On non atomic 32bit it's the same
as SEEK_SET.

=> Don't need a lock, but need to use i_size_read()

SEEK_CUR: This has a read-modify-write race window
on the same file. One could argue that any application
doing unsynchronized seeks on the same file is already broken.
But for the sake of not adding a regression here I'm
using the file->f_lock to synchronize this. Using this
lock is much better than the inode mutex because it doesn't
synchronize between processes.

=> So still need a lock, but can use a f_lock.

This patch implements this new scheme in generic_file_llseek.
I dropped generic_file_llseek_unlocked and changed all callers.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Add support to print nostrictsync and noperm mount options in
/proc/mounts for shares mounted with these options.
(cleanup merge conflict in Sachin's original patch)
Suggested-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Signed-off-by: NJeff Layton <jlayton@redhat.com>

that let us do local lock checks before requesting to the server.
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <smfrench@gmail.com>

Thus spake Jeff Layton:

"Making that a module parm would allow you to set that parameter at boot
time without needing to add special startup scripts. IMO, all of the
procfile "switches" under /proc/fs/cifs should be module parms
instead."

This patch doesn't alter the default behavior (Oplocks are enabled by
default).

To disable oplocks when loading the module, use

   modprobe cifs enable_oplocks=0

(any of '0' or 'n' or 'N' conventions can be used).

To disable oplocks at runtime using the new interface, use

   echo 0 > /sys/module/cifs/parameters/enable_oplocks

The older /proc/fs/cifs/OplockEnabled interface will be deprecated
after two releases. A subsequent patch will add an warning message
about this deprecation.

Changes since v2:
   - make enable_oplocks a 'bool'

Changes since v1:
   - eliminate the use of extra variable by renaming the old one to
     enable_oplocks and make it an 'int' type.
Reported-by: NAlexander Swen <alex@swen.nu>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSuresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: NSteve French <smfrench@gmail.com>

It should be 'CONFIG_CIFS_NFSD_EXPORT'. No-one noticed because that
symbol depends on BROKEN.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NSteve French <smfrench@gmail.com>

Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Commit d39454ff adds a strictcache mount
option. This patch allows the display of this mount option in
/proc/mounts when listing shares mounted with the strictcache mount
option.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

move it to the beginning of the loop.
Signed-off-by: NPavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

The loop around lookup_one_len doesn't handle the case where it might
return a negative dentry, which can cause an oops on the next pass
through the loop. Check for that and break out of the loop with an
error of -ENOENT if there is one.

Fixes the panic reported here:

    https://bugzilla.redhat.com/show_bug.cgi?id=727927Reported-by: NTR Bentley <home@trarbentley.net>
Reported-by: NIain Arnell <iarnell@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: stable@kernel.org
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

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: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

This converts everybody to handle SEEK_HOLE/SEEK_DATA properly.  In some cases
we just return -EINVAL, in others we do the normal generic thing, and in others
we're simply making sure that the properly due-dilligence is done.  For example
in NFS/CIFS we need to make sure the file size is update properly for the
SEEK_HOLE and SEEK_DATA case, but since it calls the generic llseek stuff itself
that is all we have to do.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

not used by the instances anymore.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

redundant; all callers get it duplicated in mask & MAY_NOT_BLOCK and none of
them removes that bit.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

its value depends only on inode and does not change; we might as
well store it in ->i_op->check_acl and be done with that.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add missing ->i_mutex, convert to lookup_one_len() instead of
(broken) open-coded analog, cope with getting something like
a//b as relative pathname.  Simplify the hell out of it, while
we are there...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Reviewed-by: NJeff Layton <jlayton@redhat.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>

...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>

... 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>

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

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