nilfs2: mark minor flag for checkpoint created by internal operation

Nilfs creates checkpoints even for garbage collection or metadata updates
such as checkpoint mode change.  So, user often sees checkpoints created
only by such internal operations.

This is inconvenient in some situations.  For example, application that
monitors checkpoints and changes them to snapshots, will fall into an
infinite loop because it cannot distinguish internally created
checkpoints.

This patch solves this sort of problem by adding a flag to checkpoint for
identification.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: clean up sketch file

The sketch file is a file to mark checkpoints with user data.  It was
experimentally introduced in the original implementation, and now
obsolete.  The file was handled differently with regular files; the file
size got truncated when a checkpoint was created.

This stops the special treatment and will treat it as a regular file.
Most users are not affected because mkfs.nilfs2 no longer makes this file.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: super block operations fix endian bug

This adds a missing endian conversion of checksum field in the super
block.  This fixes compatibility issue on big endian machines which will
come to surface after supporting recovery of super block.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: replace BUG_ON and BUG calls triggerable from ioctl

Pekka Enberg advised me:
> It would be nice if BUG(), BUG_ON(), and panic() calls would be
> converted to proper error handling using WARN_ON() calls. The BUG()
> call in nilfs_cpfile_delete_checkpoints(), for example, looks to be
> triggerable from user-space via the ioctl() system call.

This will follow the comment and keep them to a minimum.

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: extend nilfs_sustat ioctl struct

This adds a new argument to the nilfs_sustat structure.

The extended field allows to delete volatile active state of segments,
which was needed to protect freshly-created segments from garbage
collection but has confused code dealing with segments.  This
extension alleviates the mess and gives room for further
simplifications.

The volatile active flag is not persistent, so it's eliminable on this
occasion without affecting compatibility other than the ioctl change.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: use unlocked_ioctl

Pekka Enberg suggested converting ->ioctl operations to use
->unlocked_ioctl to avoid BKL.

The conversion was verified to be safe, so I will take it on this
occasion.

Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: remove compat ioctl code

This removes compat code from the nilfs ioctls and applies the same
function for both .ioctl and .compat_ioctl file operations.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: use fixed sized types for ioctl structures

Nilfs ioctl had structures not having fixed sized types such as:

  struct nilfs_argv {
         void *v_base;
         size_t v_nmembs;
         size_t v_size;
         int v_index;
         int v_flags;
  };

Further, some of them are wrongly aligned:

  e.g.

  struct nilfs_cpmode {
        __u64 cm_cno;
        int cm_mode;
  };

The size of wrongly aligned structures varies depending on
architectures, and it breaks the identity of ioctl commands, which
leads to arch dependent errors.

Previously, these are compensated by using compat_ioctl.

This fixes these problems and allows removal of compat ioctl.

Since this will change sizes of those structures, binary compatibility
for the past utilities will once break; new utilities have to be used
instead.  However, it would be helpful to avoid platform dependent
problems in the long term.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: remove timedwait ioctl command

This removes NILFS_IOCTL_TIMEDWAIT command from ioctl interface along
with the related flags and wait queue.

The command is terrible because it just sleeps in the ioctl.  I prefer
to avoid this by devising means of event polling in userland program.
By reconsidering the userland GC daemon, I found this is possible
without changing behaviour of the daemon and sacrificing efficiency.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: fix buggy behavior seen in enumerating checkpoints

This will fix the weird behavior of lscp command in listing continuously
created checkpoints; the output of lscp is rewinded regularly for the
recent nilfs.  As a result of debugging, a defect was found in
nilfs_cpfile_do_get_cpinfo() function.

Though the function can be repeatedly called to enumerate checkpoints and
it can skip invalid checkpoint entries, the index value was not carried
between successive calls.

The bug has long been present, and came to surface after applying a bugfix
nilfs2-fix-problems-of-memory-allocation-in-ioctl.patch, which increased
frequency of calling the function.  The similar bugfix was already applied
for ``snapshots'' by
nilfs2-fix-gc-failure-on-volumes-keeping-numerous-snapshots.patch.

This fixes the problem by making the index argument bidirectional on the
function.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: clean up indirect function calling conventions

This cleans up the strange indirect function calling convention used in
nilfs to follow the normal kernel coding style.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: fix improper return values of nilfs_get_cpinfo ioctl

A few tool developers gave me requests for fixing inconvenient return
value of nilfs_get_cpinfo() ioctl; if the requested mode is NILFS_SNAPSHOT
and the specified start entry is not a snapshot, the ioctl unnaturally
returns one as the number of acquired snapshot item.

In addition, the ioctl function returns an ENOENT error for checkpoints
within blocks deleted by garbage collection.

These behaviors require corrections for programs which enumerate
snapshots.  This resolves the inconvenience by changing the return values
to zero for the above cases.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: fix gc failure on volumes keeping numerous snapshots

This resolves the following failure of nilfs2 cleaner daemon:

 nilfs_cleanerd[20670]: cannot clean segments: No such file or directory
 nilfs_cleanerd[20670]: shutdown

When creating thousands of snapshots, the cleaner daemon had rarely died
as above due to an error returned from the kernel code.

After applying the recent patch which fixed memory allocation problems in
ioctl (Message-Id: <20081215.155840.105124170.ryusuke@osrg.net>), the
problem gets more frequent.

It turned out to be a bug of nilfs_ioctl_wrap_copy function and one of its
callback routines to read out information of snapshots; if the
nilfs_ioctl_wrap_copy function divided a large read request into multiple
requests, the second and later requests have failed since a restart
position on snapshot meta data was not properly set forward.

It's a deficiency of the callback interface that cannot pass the restart
position among multiple requests.  This patch fixes the issue by allowing
nilfs_ioctl_wrap_copy and snapshot read functions to exchange a position
argument.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: add maintainer

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: insert explanations in gcinode file

The file gcinode.c gives buffer cache functions for on-disk blocks
moved in garbage collection.  Joern Engel has suggested inserting its
explanations in the source file (Message-ID:
<20080917144146.GD8750@logfs.org> and
<20080917224953.GB14644@logfs.org>).

This follows the comment.

Cc: Joern Engel <joern@logfs.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: avoid double error caused by nilfs_transaction_end

Pekka Enberg pointed out that double error handlings found after
nilfs_transaction_end() can be avoided by separating abort operation:

 OK, I don't understand this. The only way nilfs_transaction_end() can
 fail is if we have NILFS_TI_SYNC set and we fail to construct the
 segment. But why do we want to construct a segment if we don't commit?

 I guess what I'm asking is why don't we have a separate
 nilfs_transaction_abort() function that can't fail for the erroneous
 case to avoid this double error value tracking thing?

This does the separation and renames nilfs_transaction_end() to
nilfs_transaction_commit() for clarification.

Since, some calls of these functions were used just for exclusion control
against the segment constructor, they are replaced with semaphore
operations.

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: cleanup nilfs_clear_inode

This will remove the following unnecessary locks and cleanup code in
nilfs_clear_inode():

- unnecessary protection using nilfs_transaction_begin() and
  nilfs_transaction_end().

- cleanup code of i_dirty list field which is never chained
  when this function is called.

- spinlock used when releasing i_bh field.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: fix problems of memory allocation in ioctl

This is another patch for fixing the following problems of a memory
copy function in nilfs2 ioctl:

(1) It tries to allocate 128KB size of memory even for small objects.

(2) Though the function repeatedly tries large memory allocations
    while reducing the size, GFP_NOWAIT flag is not specified.
    This increases the possibility of system memory shortage.

(3) During the retries of (2), verbose warnings are printed
    because _GFP_NOWARN flag is not used for the kmalloc calls.

The first patch was still doing large allocations by kmalloc which are
repeatedly tried while reducing the size.

Andi Kleen told me that using copy_from_user for large memory is not
good from the viewpoint of preempt latency:

 On Fri, 12 Dec 2008 21:24:11 +0100, Andi Kleen <andi@firstfloor.org> wrote:
 > > In the current interface, each data item is copied twice: one is to
 > > the allocated memory from user space (via copy_from_user), and another
 >
 > For such large copies it is better to use multiple smaller (e.g. 4K)
 > copy user, that gives better real time preempt latencies. Each cfu has a
 > cond_resched(), but only one, not multiple times in the inner loop.

He also advised me that:

 On Sun, 14 Dec 2008 16:13:27 +0100, Andi Kleen <andi@firstfloor.org> wrote:
 > Better would be if you could go to PAGE_SIZE. order 0 allocations
 > are typically the fastest / least likely to stall.
 >
 > Also in this case it's a good idea to use __get_free_pages()
 > directly, kmalloc tends to be become less efficient at larger
 > sizes.

For the function in question, the size of buffer memory can be reduced
since the buffer is repeatedly used for a number of small objects.  On
the other hand, it may incur large preempt latencies for larger buffer
because a copy_from_user (and a copy_to_user) was applied only once
each cycle.

With that, this revision uses the order 0 allocations with
__get_free_pages() to fix the original problems.

Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: update makefile and Kconfig

This adds a Makefile for the nilfs2 file system, and updates the
makefile and Kconfig file in the file system directory.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: ioctl operations

This adds userland interface implemented with ioctl.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: block cache for garbage collection

This adds the cache of on-disk blocks to be moved in garbage
collection.  The disk blocks are held with dummy inodes (called
gcinodes), and this file provides lookup function of the dummy inodes,
and their buffer read function.

Signed-off-by: Seiji Kihara <kihara.seiji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Yoshiji Amagai <amagai.yoshiji@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: another dat for garbage collection

NILFS2 uses another DAT inode during garbage collection to ensure
atomicity and consistency of the DAT in the transient state.  This
twin inode is called GCDAT.

This adds functions to initialize the GCDAT and to switch page caches
and B-tree node caches between these two inodes.

Signed-off-by: Seiji Kihara <kihara.seiji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Yoshiji Amagai <amagai.yoshiji@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: recovery functions

This adds recovery function on mount.

Usually the recovery is achieved by just finding the latest super
root.  When logs without checkpoints were appended for data sync
operations after the latest super root, the recovery function will
perform roll forwarding and reconstruct new log(s) with a super root.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: fix missed-sync issue for do_sync_mapping_range()

Chris Mason pointed out that there is a missed sync issue in
nilfs_writepages():

On Wed, 17 Dec 2008 21:52:55 -0500, Chris Mason wrote:
> It looks like nilfs_writepage ignores WB_SYNC_NONE, which is used by
> do_sync_mapping_range().

where WB_SYNC_NONE in do_sync_mapping_range() was replaced with
WB_SYNC_ALL by Nick's patch (commit:
ee53a891f47444c53318b98dac947ede963db400).

This fixes the problem by letting nilfs_writepages() write out the log of
file data within the range if sync_mode is WB_SYNC_ALL.

This involves removal of nilfs_file_aio_write() which was previously
needed to ensure O_SYNC sync writes.

Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: segment constructor

This adds the segment constructor (also called log writer).

The segment constructor collects dirty buffers for every dirty inode,
makes summaries of the buffers, assigns disk block addresses to the
buffers, and then submits BIOs for the buffers.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: segment buffer

This adds the segment buffer which is used to constuct logs.

[akpm@linux-foundation.org: BIO_RW_SYNC got removed]
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: super block operations

This adds super block operations for the nilfs2 file system.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: operations for the_nilfs core object

This adds functions on the_nilfs object, which keeps shared resources and
states among a read/write mount and snapshots mounts going individually.

the_nilfs is allocated per block device; it is created when user first
mount a snapshot or a read/write mount on the device, then it is reused
for successive mounts.  It will be freed when all mount instances on the
device are detached.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: pathname operations

This adds pathname operations, most of which comes from the ext2 file
system.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: directory entry operations

This adds directory handling functions, most of which comes from the ext2
file system.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Yoshiji Amagai <amagai.yoshiji@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: file operations

This adds primitives for regular file handling.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: inode operations

This adds inode level operations of the nilfs2 file system.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: segment usage file

This adds a meta data file which stores the allocation state of segments.

[konishi.ryusuke@lab.ntt.co.jp: fix wrong counting of checkpoints and dirty segments]
Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: checkpoint file

This adds a meta data file which holds checkpoint entries in its data
blocks.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: inode map file

This adds a meta data file which stores on-disk inodes in its data blocks.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Yoshiji Amagai <amagai.yoshiji@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: disk address translator

This adds the disk address translation file (DAT) whose primary function
is to convert virtual disk block numbers to actual disk block numbers.

The virtual block numbers of NILFS are associated with checkpoint
generation numbers, and this file also provides functions to manage the
lifetime information of each virtual block number.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: persistent object allocator

This adds common functions to allocate or deallocate entries with bitmaps
on a meta data file.  This feature is used by the DAT and ifile.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Yoshiji Amagai <amagai.yoshiji@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: meta data file

This adds the meta data file, which serves common buffer functions to the
DAT, sufile, cpfile, ifile, and so forth.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: buffer and page operations

This adds common routines for buffer/page operations used in B-tree
node caches, meta data files, or segment constructor (log writer).

NILFS uses copy functions for buffers and pages due to the following
reasons:

 1) Relocation required for COW
    Since NILFS changes address of on-disk blocks, moving buffers
    in page cache is needed for the buffers which are not addressed
    by a file offset.  If buffer size is smaller than page size,
    this involves partial copy of pages.

 2) Freezing mmapped pages
    NILFS calculates checksums for each log to ensure its validity.
    If page data changes after the checksum calculation, this validity
    check will not work correctly.  To avoid this failure for mmaped
    pages, NILFS freezes their data by copying.

 3) Copy-on-write for DAT pages
    NILFS makes clones of DAT page caches in a copy-on-write manner
    during GC processes, and this ensures atomicity and consistency
    of the DAT in the transient state.

In addition, NILFS uses two obsolete functions, nilfs_mark_buffer_dirty()
and nilfs_clear_page_dirty() respectively.

* nilfs_mark_buffer_dirty() was required to avoid NULL pointer
  dereference faults:

  Since the page cache of B-tree node pages or data page cache of pseudo
  inodes does not have a valid mapping->host, calling mark_buffer_dirty()
  for their buffers causes the fault; it calls __mark_inode_dirty(NULL)
  through __set_page_dirty().

* nilfs_clear_page_dirty() was needed in the two cases:

 1) For B-tree node pages and data pages of the dat/gcdat, NILFS2 clears
    page dirty flags when it copies back pages from the cloned cache
    (gcdat->{i_mapping,i_btnode_cache}) to its original cache
    (dat->{i_mapping,i_btnode_cache}).

 2) Some B-tree operations like insertion or deletion may dispose buffers
    in dirty state, and this needs to cancel the dirty state of their
    pages.  clear_page_dirty_for_io() caused faults because it does not
    clear the dirty tag on the page cache.

Signed-off-by: Seiji Kihara <kihara.seiji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: B-tree node cache

This adds routines for B-tree node buffers.

Signed-off-by: Seiji Kihara <kihara.seiji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: direct block mapping

This adds block mappings using direct pointers which are stored in the
i_bmap array of inode.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: B-tree based block mapping

This adds declarations and functions of NILFS2 B-tree.

Two variants are integrated in the NILFS2 B-tree.  The B-tree for the most
files points to the child nodes or data blocks with virtual block
addresses, whereas the B-tree of the DAT uses actual block addresses.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: integrated block mapping

This adds structures and operations for the block mapping (bmap for
short).  NILFS2 uses direct mappings for short files or B-tree based
mappings for longer files.

Every on-disk data block is held with inodes and managed through this
block mapping.  The nilfs_bmap structure and a set of functions here
provide this capability to the NILFS2 inode.

[penberg@cs.helsinki.fi: remove a bunch of bmap wrapper macros]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: add inode and other major structures

This adds the following common structures of the NILFS2 file system.

* nilfs_inode_info structure:
  gives on-memory inode.

* nilfs_sb_info structure:
  keeps per-mount state and a special inode for the ifile.
  This structure is attached to the super_block structure.

* the_nilfs structure:
  keeps shared state and locks among a read/write mount and snapshot
  mounts.  This keeps special inodes for the sufile, cpfile, dat, and
  another dat inode used during GC (gcdat).  This also has a hash table
  of dummy inodes to cache disk blocks during GC (gcinodes).

* nilfs_transaction_info structure:
  keeps per task state while nilfs is writing logs or doing indivisible
  inode or namespace operations.  This structure is used to identify
  context during log making and store nest level of the lock which
  ensures atomicity of file system operations.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: disk format and userland interface

This adds a header file which specifies the on-disk format and ioctl
interface of the nilfs2 file system.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nilfs2: add document

This adds a document describing the features, mount options, userland
tools, usage, disk format, and related URLs for the nilfs2 file system.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: update the old macro DMA_nBIT_MASK related documentations

Update the old macro DMA_nBIT_MASK related documentations

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24)

Replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: replace all DMA_28BIT_MASK macro with DMA_BIT_MASK(28)

Replace all DMA_28BIT_MASK macro with DMA_BIT_MASK(28)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: replace all DMA_30BIT_MASK macro with DMA_BIT_MASK(30)

Replace all DMA_30BIT_MASK macro with DMA_BIT_MASK(30)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: replace all DMA_31BIT_MASK macro with DMA_BIT_MASK(31)

Replace all DMA_31BIT_MASK macro with DMA_BIT_MASK(31)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32)

Replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: replace all DMA_39BIT_MASK macro with DMA_BIT_MASK(39)

Replace all DMA_39BIT_MASK macro with DMA_BIT_MASK(39)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: replace all DMA_40BIT_MASK macro with DMA_BIT_MASK(40)

Replace all DMA_40BIT_MASK macro with DMA_BIT_MASK(40)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: replace all DMA_48BIT_MASK macro with DMA_BIT_MASK(48)

Replace all DMA_48BIT_MASK macro with DMA_BIT_MASK(48)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: replace all DMA_64BIT_MASK macro with DMA_BIT_MASK(64)

Replace all DMA_64BIT_MASK macro with DMA_BIT_MASK(64)

Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/romfs: return f_fsid for statfs(2)

Make romfs return f_fsid info for statfs(2).

Signed-off-by: Coly Li <coly.li@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

namespaces: mqueue namespace: adapt sysctl

Largely inspired from ipc/ipc_sysctl.c.  This patch isolates the mqueue
sysctl stuff in its own file.

[akpm@linux-foundation.org: build fix]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

namespaces: ipc namespaces: implement support for posix msqueues

Implement multiple mounts of the mqueue file system, and link it to usage
of CLONE_NEWIPC.

Each ipc ns has a corresponding mqueuefs superblock.  When a user does
clone(CLONE_NEWIPC) or unshare(CLONE_NEWIPC), the unshare will cause an
internal mount of a new mqueuefs sb linked to the new ipc ns.

When a user does 'mount -t mqueue mqueue /dev/mqueue', he mounts the
mqueuefs superblock.

Posix message queues can be worked with both through the mq_* system calls
(see mq_overview(7)), and through the VFS through the mqueue mount.  Any
usage of mq_open() and friends will work with the acting task's ipc
namespace.  Any actions through the VFS will work with the mqueuefs in
which the file was created.  So if a user doesn't remount mqueuefs after
unshare(CLONE_NEWIPC), mq_open("/ab") will not be reflected in "ls
/dev/mqueue".

If task a mounts mqueue for ipc_ns:1, then clones task b with a new ipcns,
ipcns:2, and then task a is the last task in ipc_ns:1 to exit, then (1)
ipc_ns:1 will be freed, (2) it's superblock will live on until task b
umounts the corresponding mqueuefs, and vfs actions will continue to
succeed, but (3) sb->s_fs_info will be NULL for the sb corresponding to
the deceased ipc_ns:1.

To make this happen, we must protect the ipc reference count when

a) a task exits and drops its ipcns->count, since it might be dropping
   it to 0 and freeing the ipcns

b) a task accesses the ipcns through its mqueuefs interface, since it
   bumps the ipcns refcount and might race with the last task in the ipcns
   exiting.

So the kref is changed to an atomic_t so we can use
atomic_dec_and_lock(&ns->count,mq_lock), and every access to the ipcns
through ns = mqueuefs_sb->s_fs_info is protected by the same lock.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

namespaces: mqueue ns: move mqueue_mnt into struct ipc_namespace

Move mqueue vfsmount plus a few tunables into the ipc_namespace struct.
The CONFIG_IPC_NS boolean and the ipc_namespace struct will serve both the
posix message queue namespaces and the SYSV ipc namespaces.

The sysctl code will be fixed separately in patch 3.  After just this
patch, making a change to posix mqueue tunables always changes the values
in the initial ipc namespace.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

namespaces: move proc_net_get_sb to a generic fs/super.c helper

The mqueuefs filesystem will use this helper as well.  Proc's main get_sb
could also be made to use it, but that will require a bit more rework.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

uvesafb: documentation update

Update the uvesafb documentation to accurately reflect the default options
used by the driver.

Signed-off-by: Michal Januszewski <spock@gentoo.org>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fbdev: i.MX31: fix panning, error handling, clean up

1. check for errors returned from clk_get()
2. fix "Unbalanced enable for IRQ 160"
3. fix transmit descriptor handling in panning
4. clean frame buffer on blank - useful for OLED displays
5. formatting clean up

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tdfxfb: make use of DDC information about connected monitor

Read DDC information from a connected monitor and use it to select initial
mode (if the mode is not specified).

Also, use the information to protect against modes outside the monitor
specs.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Tested-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tdfxfb: move I2C functionality into the tdfxfb

The I2C functionality provided by the i2c-voodoo3 driver is moved into the
tdfxfb (frame buffer driver for Voodoo3 cards).  This way there is no
conflict between the i2c driver and the fb driver.

The tdfxfb does not make use from the DDC functionality yet but provides
all the functionality of the i2c-voodoo3 driver.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kprobes: support kretprobe and jprobe per-probe disabling

Add disable/enable_kretprobe() and disable/enable_jprobe().

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kprobes: support per-kprobe disabling

Add disable_kprobe() and enable_kprobe() to disable/enable kprobes
temporarily.

disable_kprobe() asynchronously disables probe handlers of specified
kprobe.  So, after calling it, some handlers can be called at a while.
enable_kprobe() enables specified kprobe.

aggr_pre_handler and aggr_post_handler check disabled probes.  On the
other hand aggr_break_handler and aggr_fault_handler don't check it
because these handlers will be called while executing pre or post handlers
and usually those help error handling.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kprobes: rename kprobe_enabled to kprobes_all_disarmed

Rename kprobe_enabled to kprobes_all_disarmed and invert logic due to
avoiding naming confusion from per-probe disabling.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kprobes: cleanup comment style in kprobes.h

Fix comment style in kprobes.h.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kprobes: move EXPORT_SYMBOL_GPL just after function definitions

Clean up positions of EXPORT_SYMBOL_GPL in kernel/kprobes.c according to
checkpatch.pl.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kprobes: cleanup aggr_kprobe related code

Currently, kprobes can disable all probes at once, but can't disable it
individually (not unregister, just disable an kprobe, because
unregistering needs to wait for scheduler synchronization).  These patches
introduce APIs for on-the-fly per-probe disabling and re-enabling by
dis-arming/re-arming its breakpoint instruction.

This patch:

Change old_p to ap in add_new_kprobe() for readability, copy flags member
in add_aggr_kprobe(), and simplify the code flow of
register_aggr_kprobe().

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

spi_imx: set spi_master.dma_alignment = 4

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

pxa2xx_spi: set spi_master.dma_alignment = 8

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

SPI: add dma_alignment field to spi_master

Some SPI controllers have restrictions on DMAable buffers alignemt.
Currently if the buffer supplied by protocol driver is not properly
aligned, the controller silently performs transfer in PIO mode.  Addition
of dma_alignment field to spi_master allows protocol drivers to perform
proper alignment.

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

spi_bfin5xx: remove unused IS_DMA_ALIGNED macro

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

spi: pxa2xx_spi: introduce chipselect GPIO to simplify the common cases

Most SPI peripherals use GPIOs as their chip selects, introduce .gpio_cs
for this.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

spi: limit reaches -1, tested 0

With a postfix decrement limit will reach -1 rather than 0, so the warning
will not be issued.

Also, add a cpu_relax() into the busy-wait loop.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Mariusz Ceier <mceier@gmail.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: Make mmc_spi driver work on Blackfin

1. Rewrite of the non-dma data transfer functions to use only ONE mode
   of TIMOD (TIMOD=0x1).  With TIMOD=0, it was not possible to set the TX
   bit pattern.  So the TDBR = 0xFFFF inside the read calls won't work.

2. Clear SPI_RDBR before reading and before duplex transfer.
   Otherwise the garbage data in RDBR will get read.  Since mmc_spi uses a
   lot of duplex transfers, this is the main cause of mmc_spi failure.

3. Poll RXS for transfer completion.  Polling SPIF or TXS cannot
   guarantee transfer completion.  This may interrupt a transfer before it
   is finished.  Also this may leave garbage data in buffer and affect
   next transfer.

[Yi Li <yi.li@analog.com>: add a field "u16 idle_tx_val" in "struct
bfin5xx_spi_chip" to specify the value to transmit if no TX value
is supplied.]
Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de>
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: Add GPIO controlled SPI Slave Select support

Add support for GPIO controlled SPI Chip Selects.  To make use of this
feature, set chip_select = 0 and add a proper cs_gpio to your
controller_data.

struct spi_board_info
        .chip_select = 0

struct bfin5xx_spi_chip
        .cs_gpio = GPIO_P###

There are various SPI devices that require SPI MODE_0, and need to have
the Chip Selects asserted during the entire transfer.  Consider using
SPI_MODE_3 (SPI_CPHA | SPI_CPOL) if your device allows it.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: fix NULL pointer crash

Fix NULL pointer crash when cleaning up from invalid platform resources

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: use bfin_spi_ prefix on all functions

Do this because when things crash, we get simple names like "setup" and
"start_queue" which is pretty difficult to trace back to the real thing:
the spi driver

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: fix bug - correct usage of struct spi_transfer.cs_change

According to comments in linux/spi/spi.h:

 * All SPI transfers start with the relevant chipselect active.  Normally
 * it stays selected until after the last transfer in a message. Drivers
 * can affect the chipselect signal using cs_change.
 *
 * (i) If the transfer isn't the last one in the message, this flag is
 * used to make the chipselect briefly go inactive in the middle of the
 * message.  Toggling chipselect in this way may be needed to terminate
 * a chip command, letting a single spi_message perform all of group of
 * chip transactions together.
 *
 * (ii) When the transfer is the last one in the message, the chip may
 * stay selected until the next transfer.  On multi-device SPI busses
 * with nothing blocking messages going to other devices, this is just
 * a performance hint; starting a message to another device deselects
 * this one.  But in other cases, this can be used to ensure correctness.
 * Some devices need protocol transactions to be built from a series of
 * spi_message submissions, where the content of one message is determined
 * by the results of previous messages and where the whole transaction
 * ends when the chipselect goes intactive.

Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: fix bug - spi controller driver does not assert/deassert CS correctly

This bug can be observed when two SPI devices are sharing the spi bus: One
device is set as SPI CS 7, another one is using SPI CS 4.

In spi_bfin5xx.c: cs_active(), cs_deactive() are used to control SPI_FLG
register.  From the debug bellow:

cs_active: flag: 0x7f91, chip->flag: 0x7f80, cs: 7
cs_active: flag: 0xef91, chip->flag: 0xef10, cs: 4

When device A (cs_7) activate CS 7, SPI_FLG is set as 0x7f91 (however,
SPI_FLG should be set as 0x7f80, or 0x6f91 if in broadcast mode).

Due to some HW bug (very possibly), if SPI_FLG is set as 0x7f91, SPISSEL7
is asserted, however SPISSEL4 will be asserted too (I can see this using
the scope).  This is unreasonable according to HRM.

Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: tweak magic spi dma sequence to get it working on BF54x

Without this change, SPI DMA is not reliably under stress tests.
Obiviously it's a hardware issue which is not addressed by any document.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: add timeout while waiting for SPIF in dma irq handler

The "while" endless loop will cause the system hang if hardware error, so
we add timeout control to make the system alive.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: get dma working for SPI flashes

When using a BF533-STAMP here with a W25X10 SPI flash.  It works fine when
enable_dma is disabled, but doesn't work at all when turning DMA on.  We
get just 0xff bytes back when trying to read the device.

Change the code around so that it programs the SPI first and then enables
DMA, it seems to work a lot better ...

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: SPI slave select code cleanup

- remove duplicated definition MAX_SPI_SSEL

- remove unnecessary array size

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: use the properl BIT_CTL_xxx defines

use the properl BIT_CTL_...  defines rather than the internal driv er
CFG_SPI_...  defines

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: do not check for SPI errors if DMA itself did not flag any

We only need to check SPI error when DMA failes, cause that is the DMA IRQ
handling routine.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: add a few more DMA debug messages

Because of DMA hardware issue, we were trying to use software workaround.
This patch add some useful debug messages to help us debugging the DMA
code.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: drop bogus cast and touchup dma label

Blackfin's related DMA callback API doesn't need void * cast, so drop it.
And this driver is for all Blackfin processors not only for BF53x, we
update the DMA request label for more meaningful information.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: unify duplicated code in dma read/write paths

For DMA TX/RX operation in pump_transfers, DMA contriguration code in TX
and RX paths are almost the same.  This patch unify the duplicated DMA
code to make it more readable.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: pass DMA overflow error to the higher level

If the SPI bus registers a receive overflow error, pass the result back up
to the higher levels.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: use len_in_bytes when we care about the number of bytes transferred

Use len_in_bytes when we care about the number of bytes transferred rather
than the number of spi transactions.  (this value will be the same for
8bit transfers, but not any other sizes)

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: remove useless <asm/cplbinit.h>

We already moved bfin_addr_dcachable() and friends into the cacheflush
header where it belongs, so don't need to include <asm/cplbinit.h> here.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: Fix erroneous SPI Clock divisor calculation

Fix erroneous SPI Clock divisor calculation.  Make sure SPI_BAUD is always
>= 2.  Writing a value of 0 or 1 to the SPI_BAUD register disables the
serial clock.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Blackfin SPI Driver: ensure cache coherency before doing DMA

Flush or invalidate caches before doing DMA transfer, if needed.

[Mike Frysinger <vapier.adi@gmail.com>: add comment to address the
issue "Full duplex only works for non-DMA transfers".]
Signed-off-by: Vitja Makarov <vitja.makarov@gmail.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

hwmon: add support for GMT G760A fan speed PWM controller

This controller can be found on the D-Link DNS-323 for instance, where
it is to be configured via static i2c_board_info in the board-specific
mach-orion/dns323-setup.c; this driver supports only the new-style
driver model.

Tested-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Signed-off-by: Matthew Palmer <mpalmer@debian.org>
Signed-off-by: Laurie Bradshaw <bradshaw.laurie@googlemail.com>
Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

/proc/pid/maps: don't show pgoff of pure ANON VMAs

Recently, it's argued that what proc/pid/maps shows is ugly when a 32bit
binary runs on 64bit host.

/proc/pid/maps outputs vma's pgoff member but vma->pgoff is of no use
information is the vma is for ANON.  With this patch, /proc/pid/maps shows
just 0 if no file backing store.

[akpm@linux-foundation.org: coding-style fixes]
[kamezawa.hiroyu@jp.fujitsu.com: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mike Waychison <mikew@google.com>
Reported-by: Ying Han <yinghan@google.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: add /proc controls for pdflush threads

Add /proc entries to give the admin the ability to control the minimum and
maximum number of pdflush threads.  This allows finer control of pdflush
on both large and small machines.

The rationale is simply one size does not fit all.  Admins on large and/or
small systems may want to tune the min/max pdflush thread count to best
suit their needs.  Right now the min/max is hardcoded to 2/8.  While
probably a fair estimate for smaller machines, large machines with large
numbers of CPUs and large numbers of filesystems/block devices may benefit
from larger numbers of threads working on different block devices.

Even if the background flushing algorithm is radically changed, it is
still likely that multiple threads will be involved and admins would still
desire finer control on the min/max other than to have to recompile the
kernel.

The patch adds '/proc/sys/vm/nr_pdflush_threads_min' and
'/proc/sys/vm/nr_pdflush_threads_max' with r/w permissions.

The minimum value for nr_pdflush_threads_min is 1 and the maximum value is
the current value of nr_pdflush_threads_max.  This minimum is required
since additional thread creation is performed in a pdflush thread itself.

The minimum value for nr_pdflush_threads_max is the current value of
nr_pdflush_threads_min and the maximum value can be 1000.

Documentation/sysctl/vm.txt is also updated.

[akpm@linux-foundation.org: fix comment, fix whitespace, use __read_mostly]
Signed-off-by: Peter W Morreale <pmorreale@novell.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>