While traversing the linked list of open file handles, if the identfied
file handle is invalid, a reopen is attempted and if it fails, we
resume traversing where we stopped and cifs can oops while accessing
invalid next element, for list might have changed.

So mark the invalid file handle and attempt reopen if no
valid file handle is found in rest of the list.
If reopen fails, move the invalid file handle to the end of the list
and start traversing the list again from the begining.
Repeat this four times before giving up and returning an error if
file reopen keeps failing.

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

For more details see <file: Documentation/filesystems/porting>.
Signed-off-by: NSedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

As with Linux nfs client, which uses "nfsvers=" or "vers=" to
indicate which protocol to use for mount, specifying

"vers=2.1"

will force an SMB2 mount. When vers is not specified CIFS is used

"vers=1"

We can eventually autonegotiate down from SMB2 to CIFS
when SMB2 is stable enough to make it the default, but this
is for the future. At that time we could also implement a
"maxprotocol" mount option as smbclient and Samba have today,
but that would be premature until SMB2 is stable.

Intially the SMB2 Kconfig option will depend on "BROKEN"
until the merge is complete, and then be "EXPERIMENTAL"
When it is no longer experimental we can consider changing
the default protocol to attempt first.
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

SMB2 is the followon to the CIFS (and SMB) protocols
and the default for Windows since Windows Vista, and also
now implemented by various non-Windows servers. SMB2
is more secure, has various performance advantages, including
larger i/o sizes, flow control, better caching model and more.
SMB2 also resolves some scalability limits in the CIFS
protocol and adds many new features while being much
simpler (only a few dozen commands instead of hundreds)
and since the protocol is clearer it is also more consistently
implemented across servers and thus easier to optimize.

After much discussion with Jeff Layton, Jeremy Allison
and others at Connectathon, we decided to move the SMB2
code from a distinct .ko and fstype into distinct
C files that optionally build in cifs.ko. As a result
the Kconfig gets simpler.

To avoid destabilizing CIFS, the SMB2 code is going
to be moved into its own experimental CONFIG_CIFS_SMB2 ifdef
as it is merged and rereviewed. The changes to stable
CIFS (builds with the SMB2 ifdef off) are expected to be
fairly small.
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Acked-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Acked-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Acked-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Acked-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Acked-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

As observed and suggested by Tushar Gosavi...

---------
readdir calls these function to send TRANS2_FIND_FIRST and
TRANS2_FIND_NEXT command to the server. The current cifs module is
not specifying CIFS_SEARCH_BACKUP_SEARCH flag while sending these
command when backupuid/backupgid is specified. This can be resolved
by specifying CIFS_SEARCH_BACKUP_SEARCH flag.
---------

Cc: <stable@kernel.org>
Reported-and-Tested-by: NTushar Gosavi <tugosavi@in.ibm.com>
Signed-off-by: NShirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>

Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>

Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>

to handle SMB2 lock type field further.
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>

CIFS brlock cache can be used by several file handles if we have a
write-caching lease on the file that is supported by SMB2 protocol.
Prepate the code to handle this situation correctly by sorting brlocks
by a fid to easily push them in portions when lease break comes.
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>

For SMB2, this should be a no-op. Obviously if we wanted to do something
for the SMB2 case, we could also define an operation here for it.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>

We need a way to dispatch different operations for different versions.
Behold the smb_version_operations/values structures. For now, those
structures just hold the version enum value and nothing uses them.
Eventually, we'll expand them to cover other operations/values as we
change the callers to dispatch from here.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>

We want these to mean something different entirely, and the mount.cifs
helper only ever passed in ver= automatically. Also, don't allow
ver=cifs anymore since that was never passed in by the mount helper.
Signed-off-by: NJeff Layton <jlayton@redhat.com>

Add a warning that will be displayed when there is no cache= option
specified. We want to ensure that users are aware of the change in
defaults coming in 3.7.
Reviewed-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NJeff Layton <jlayton@redhat.com>

...and deprecate the display of strictcache, forcedirectio, and fsc
as separate options.
Reviewed-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NJeff Layton <jlayton@redhat.com>

Leave them in for 2 releases and remove for 3.7.
Reviewed-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NJeff Layton <jlayton@redhat.com>

Currently, we have several mount options that control cifs' cache
behavior, but those options aren't considered to be mutually exclusive.
The result is poorly-defined when someone specifies more than one of
these options at mount time.

Fix this by adding a new cache= mount option that will supercede
"strictcache", and "forcedirectio". That will help make it clear that
these options are mutually exclusive. Also, change the legacy options to
be mutually exclusive too, to ensure that users don't get surprises.
Reviewed-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NJeff Layton <jlayton@redhat.com>

This was used by an ancient version of umount.cifs and in nowhere else
that I'm aware of. Let's add a warning now and dump it for 3.7.
Signed-off-by: NJeff Layton <jlayton@redhat.com>

We've now warned about this for two releases. Remove it for 3.5.
Signed-off-by: NJeff Layton <jlayton@redhat.com>

Convert cifs_iovec_read to use async I/O. This also raises the limit on
the rsize for uncached reads. We first allocate a set of pages to hold
the replies, then issue the reads in parallel and then collect the
replies and copy the results into the iovec.

A possible future optimization would be to kmap and inline the iovec
buffers and read the data directly from the socket into that. That would
require some rather complex conversion of the iovec into a kvec however.
Signed-off-by: NJeff Layton <jlayton@redhat.com>

We'll need this same bit of code for the uncached case.
Signed-off-by: NJeff Layton <jlayton@redhat.com>

This isn't strictly necessary for the async readpages code, but the
uncached version will need to be able to collect the replies after
issuing the calls. Add a kref to cifs_readdata and use change the
code to take and put references appropriately.
Signed-off-by: NJeff Layton <jlayton@redhat.com>

Cached and uncached reads will need to do different things here to
handle the difference when the pages are in pagecache and not. Abstract
out the function that marshals the page list into a kvec array.
Signed-off-by: NJeff Layton <jlayton@redhat.com>

We'll need different completion routines for an uncached read. Allow
the caller to set the one he needs at allocation time. Also, move
most of these functions to file.c so we can make more of them static.
Signed-off-by: NJeff Layton <jlayton@redhat.com>

...and add a "directio" synonym since that's what the manpage has
always advertised.
Acked-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

This test is always true so it means we revalidate the length every
time, which generates more network traffic.  When it is SEEK_SET or
SEEK_CUR, then we don't need to revalidate.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>

The problem was that the first referral was parsed more than once
and so the caller tried the same referrals multiple times.

The problem was introduced partly by commit
066ce689,
where 'ref += le16_to_cpu(ref->Size);' got lost,
but that was also wrong...

Cc: <stable@vger.kernel.org>
Signed-off-by: NStefan Metzmacher <metze@samba.org>
Tested-by: NBjörn Jacke <bj@sernet.de>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Older mount.cifs programs passed this on to the kernel after parsing
the file. Make sure the kernel ignores that option.

Should fix:

    https://bugzilla.kernel.org/show_bug.cgi?id=43195

Cc: Sachin Prabhu <sprabhu@redhat.com>
Reported-by: NRonald <ronald645@gmail.com>
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>

When revalidating a dentry, if the inode wasn't known to be a dfs
entry when the dentry was instantiated, such as when created via
->readdir(), the DCACHE_NEED_AUTOMOUNT flag needs to be set on the
dentry in ->d_revalidate().

The false return from cifs_d_revalidate(), due to the inode now
being marked with the S_AUTOMOUNT flag, might not invalidate the
dentry if there is a concurrent unlazy path walk. This is because
the dentry reference count will be at least 2 in this case causing
d_invalidate() to return EBUSY. So the asumption that the dentry
will be discarded then correctly instantiated via ->lookup() might
not hold.
Signed-off-by: NIan Kent <raven@themaw.net>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Cc: Steve French <smfrench@gmail.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: NSteve French <sfrench@us.ibm.com>

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

While testing, I've found that even when we are able to negotiate a
much larger rsize with the server, on-the-wire reads often end up being
capped at 128k because of ra_pages being capped at that level.

Lifting this restriction gave almost a twofold increase in sequential
read performance on my craptactular KVM test rig with a 1M rsize.

I think this is safe since the actual ra_pages that the VM requests
is run through max_sane_readahead() prior to submitting the I/O. Under
memory pressure we should end up with large readahead requests being
suppressed anyway.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

Trivial patch which fixes a misplaced tab in cifs_show_options().
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

cifs_show_options uses the wrong conversion specifier for uid, gid,
rsize & wsize. Correct this to %u to match it to the variable type
'unsigned integer'.
Signed-off-by: NSachin Prabhu <sprabhu@redhat.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>