linux-toradex.git/fs/cifs/misc.c, branch v4.2.1

VFS: normal filesystems (and lustre): d_inode() annotations

2015-04-15T19:06:57+00:00

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells 
Signed-off-by: Al Viro

cifs: convert to print_hex_dump() instead of custom implementation

2014-12-08T04:48:01+00:00

This patch converts custom dumper to use native print_hex_dump() instead. The
cifs_dump_mem() will have an offsets per each line which differs it from the
original code.

In the dump_smb() we may use native print_hex_dump() as well. It will show
slightly different output in ASCII part when character is unprintable,
otherwise it keeps same structure.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Steve French

cifs: remove unused function cifs_oplock_break_wait

2014-08-11T06:31:03+00:00

Commit 743162013d40 ("sched: Remove proliferation of wait_on_bit() action
functions") has removed the call to cifs_oplock_break_wait, making this
function unused; remove it.

This fixes the following compilation warning:

  fs/cifs/misc.c:578:1: warning: ‘cifs_oplock_break_wait’ defined but not used [-Wunused-function]

Signed-off-by: Vincent Stehlé 
Cc: Steve French 
Signed-off-by: Steve French

Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6

2014-08-09T20:03:34+00:00

Pull CIFS updates from Steve French:
 "The most visible change in this set is the additional of multi-credit
  support for SMB2/SMB3 which dramatically improves the large file i/o
  performance for these dialects and significantly increases the maximum
  i/o size used on the wire for SMB2/SMB3.

  Also reconnection behavior after network failure is improved"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6: (35 commits)
  Add worker function to set allocation size
  [CIFS] Fix incorrect hex vs. decimal in some debug print statements
  update CIFS TODO list
  Add Pavel to contributor list in cifs AUTHORS file
  Update cifs version
  CIFS: Fix STATUS_CANNOT_DELETE error mapping for SMB2
  CIFS: Optimize readpages in a short read case on reconnects
  CIFS: Optimize cifs_user_read() in a short read case on reconnects
  CIFS: Improve indentation in cifs_user_read()
  CIFS: Fix possible buffer corruption in cifs_user_read()
  CIFS: Count got bytes in read_into_pages()
  CIFS: Use separate var for the number of bytes got in async read
  CIFS: Indicate reconnect with ECONNABORTED error code
  CIFS: Use multicredits for SMB 2.1/3 reads
  CIFS: Fix rsize usage for sync read
  CIFS: Fix rsize usage in user read
  CIFS: Separate page reading from user read
  CIFS: Fix rsize usage in readpages
  CIFS: Separate page search from readpages
  CIFS: Use multicredits for SMB 2.1/3 writes
  ...

[CIFS] Fix incorrect hex vs. decimal in some debug print statements

2014-08-03T02:16:48+00:00

Joe Perches and Hans Wennborg noticed that various places in the
kernel were printing decimal numbers with 0x prefix.
    printk("0x%d") or equivalent
This fixes the instances of this in the cifs driver.

CC: Hans Wennborg 
CC: Joe Perches 
Signed-off-by: Steve French

cifs: replace code with free_rsp_buf()

2014-08-01T04:11:15+00:00

The functionality provided by free_rsp_buf() is duplicated in a number
of places. Replace these instances with a call to free_rsp_buf().

Signed-off-by: Sachin Prabhu 
Reviewed-by: Shirish Pargaonkar 
Signed-off-by: Steve French

sched: Remove proliferation of wait_on_bit() action functions

2014-07-16T13:10:39+00:00

The current "wait_on_bit" interface requires an 'action'
function to be provided which does the actual waiting.
There are over 20 such functions, many of them identical.
Most cases can be satisfied by one of just two functions, one
which uses io_schedule() and one which just uses schedule().

So:
 Rename wait_on_bit and        wait_on_bit_lock to
        wait_on_bit_action and wait_on_bit_lock_action
 to make it explicit that they need an action function.

 Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io
 which are *not* given an action function but implicitly use
 a standard one.
 The decision to error-out if a signal is pending is now made
 based on the 'mode' argument rather than being encoded in the action
 function.

 All instances of the old wait_on_bit and wait_on_bit_lock which
 can use the new version have been changed accordingly and their
 action functions have been discarded.
 wait_on_bit{_lock} does not return any specific error code in the
 event of a signal so the caller must check for non-zero and
 interpolate their own error code as appropriate.

The wait_on_bit() call in __fscache_wait_on_invalidate() was
ambiguous as it specified TASK_UNINTERRUPTIBLE but used
fscache_wait_bit_interruptible as an action function.
David Howells confirms this should be uniformly
"uninterruptible"

The main remaining user of wait_on_bit{,_lock}_action is NFS
which needs to use a freezer-aware schedule() call.

A comment in fs/gfs2/glock.c notes that having multiple 'action'
functions is useful as they display differently in the 'wchan'
field of 'ps'. (and /proc/$PID/wchan).
As the new bit_wait{,_io} functions are tagged "__sched", they
will not show up at all, but something higher in the stack.  So
the distinction will still be visible, only with different
function names (gds2_glock_wait versus gfs2_glock_dq_wait in the
gfs2/glock.c case).

Since first version of this patch (against 3.15) two new action
functions appeared, on in NFS and one in CIFS.  CIFS also now
uses an action function that makes the same freezer aware
schedule call as NFS.

Signed-off-by: NeilBrown 
Acked-by: David Howells  (fscache, keys)
Acked-by: Steven Whitehouse  (gfs2)
Acked-by: Peter Zijlstra 
Cc: Oleg Nesterov 
Cc: Steve French 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown
Signed-off-by: Ingo Molnar

cifs: Wait for writebacks to complete before attempting write.

2014-04-16T18:51:46+00:00

Problem reported in Red Hat bz 1040329 for strict writes where we cache
only when we hold oplock and write direct to the server when we don't.

When we receive an oplock break, we first change the oplock value for
the inode in cifsInodeInfo->oplock to indicate that we no longer hold
the oplock before we enqueue a task to flush changes to the backing
device. Once we have completed flushing the changes, we return the
oplock to the server.

There are 2 ways here where we can have data corruption
1) While we flush changes to the backing device as part of the oplock
break, we can have processes write to the file. These writes check for
the oplock, find none and attempt to write directly to the server.
These direct writes made while we are flushing from cache could be
overwritten by data being flushed from the cache causing data
corruption.
2) While a thread runs in cifs_strict_writev, the machine could receive
and process an oplock break after the thread has checked the oplock and
found that it allows us to cache and before we have made changes to the
cache. In that case, we end up with a dirty page in cache when we
shouldn't have any. This will be flushed later and will overwrite all
subsequent writes to the part of the file represented by this page.

Before making any writes to the server, we need to confirm that we are
not in the process of flushing data to the server and if we are, we
should wait until the process is complete before we attempt the write.
We should also wait for existing writes to complete before we process
an oplock break request which changes oplock values.

We add a version specific  downgrade_oplock() operation to allow for
differences in the oplock values set for the different smb versions.

Cc: stable@vger.kernel.org
Signed-off-by: Sachin Prabhu 
Reviewed-by: Jeff Layton 
Reviewed-by: Pavel Shilovsky 
Signed-off-by: Steve French

cifs: Make big endian multiplex ID sequences monotonic on the wire

2013-11-02T17:51:53+00:00

The multiplex identifier (MID) in the SMB header is only
ever used by the client, in conjunction with PID, to match responses
from the server. As such, the endianess of the MID is not important.
However, When tracing packet sequences on the wire, protocol analyzers
such as wireshark display MID as little endian. It is much more informative
for the on-the-wire MID sequences to match debug information emitted by the
CIFS driver.  Therefore, one should write and read MID in the SMB header
assuming it is always little endian.

Observed from wireshark during the protocol negotiation
and session setup:

        Multiplex ID: 256
        Multiplex ID: 256
        Multiplex ID: 512
        Multiplex ID: 512
        Multiplex ID: 768
        Multiplex ID: 768

After this patch on-the-wire MID values begin at 1 and increase monotonically.

Introduce get_next_mid64() for the internal consumers that use the full 64 bit
multiplex identifier.

Introduce the helpers get_mid() and compare_mid() to make the endian
translation clear.

Reviewed-by: Jeff Layton 
Signed-off-by: Tim Gardner 
Signed-off-by: Steve French

cifs: Remove redundant multiplex identifier check from check_smb_hdr()

2013-10-28T14:31:36+00:00

The only call site for check_smb_header() assigns 'mid' from the SMB
packet, which is then checked again in check_smb_header(). This seems
like redundant redundancy.

Reviewed-by: Jeff Layton 
Signed-off-by: Tim Gardner 
Signed-off-by: Steve French