Move the call to vmtruncate to get rid of accessive blocks to the callers
in preparation of the new truncate sequence and rename the non-truncating
version to block_write_begin.

While we're at it also remove several unused arguments to block_write_begin.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Split up the block_write_begin implementation - __block_write_begin is a new
trivial wrapper for block_prepare_write that always takes an already
allocated page and can be either called from block_write_begin or filesystem
code that already has a page allocated.  Remove the handling of already
allocated pages from block_write_begin after switching all callers that
do it to __block_write_begin.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

For filesystem that implement directories in pagecache we call
block_write_begin with an already allocated page for this code, while the
normal regular file write path uses the default block_write_begin behaviour.

Get rid of the __foofs_write_begin helper and opencode the normal write_begin
call in foofs_write_begin, while adding a new foofs_prepare_chunk helper for
the directory code.  The added benefit is that foofs_prepare_chunk has
a much saner calling convention.

Note that the interruptible flag passed into block_write_begin is always
ignored if we already pass in a page (see next patch for details), and
we never were doing truncations of exessive blocks for this case either so we
can switch directly to block_write_begin_newtrunc.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Move the call to vmtruncate to get rid of accessive blocks to the callers
in prepearation of the new truncate calling sequence.  This was only done
for DIO_LOCKING filesystems, so the __blockdev_direct_IO_newtrunc variant
was not needed anyway.  Get rid of blockdev_direct_IO_no_locking and
its _newtrunc variant while at it as just opencoding the two additional
paramters is shorted than the name suffix.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The commit 41c88bd7 ("nilfs2: cleanup multi
kmem_cache_{create,destroy} code") consolidated slab constructors and
destructors used in nilfs, but it left some declarations in header
files.

This gets rid of the obsolete declarations.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This gets rid of unwanted space chars in front of conditional
sentences of nilfs_destroy_cachep().
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Acked-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Snapshots and regular ro/rw mounts are essentially-different within
the meaning whether the checkpoint is static or not and is marked with
a snapshot flag or not.

The current implemenation, however, allows to remount a snapshot to a
regular rw-mount if the checkpoint number equals the latest one.

This transition is actually impossible since changing a checkpoint to
a snapshot makes another checkpoint, thus the condition is never
satisfied.

This fixes the weird state of affairs, and specifically separates
snapshots and regular rw/ro-mounts.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This replaces uses of new_encode_dev/new_decode_dev with their 64-bit
counterparts, huge_encode_dev/huge_decode_dev respectively.

This is just for clarification and has no impact on the disk format.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

deactivate_super was replaced with deactivate_locked_super, but the
comment of nilfs_get_sb remain unchanged.  This renews the comment.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

MS_VERBOSE is deprecated.  This replaces it with MS_SILENT in
reference to get_sb_bdev function.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

An fmode_t argument is passed to kill_block_super() through s_mode
member of the super_block structure.  This is used to release the
block device with the same mode, however, nilfs does not set s_mode
anywhere.

This modifies nilfs_get_sb function to properly initialize the s_mode
member.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

The second argument of open_bdev_exclusive/close_bdev_exclusive takes
fmode_t flags instead of mount flags.  This fixes the misuse.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

Nilfs maintains two super blocks, and selects the new one on mount
time if they both have valid checksums and their timestamps differ.

However, this has potential for mis-selection since the system clock
may be rewinded and the resolution of the timestamps is not high.

Usually this doesn't become an issue because both super blocks are
updated at the same time when the file system is unmounted.  Even if
the file system wasn't unmounted cleanly, the roll-forward recovery
will find the proper log which stores the latest super root.  Thus,
the issue can appear only if update of one super block fails and the
clock happens to be rewinded.

This fixes the issue by using checkpoint numbers instead of timestamps
to pick the super block storing the location of the latest log.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This adds missing endian conversions in comparision of the magic
number of super blocks.  It was coincidence that prior versions didn't
incur problems; the upper byte of the magic number happened to be
equal to the lower byte.  But, semantically it's wrong to depend on
this.

This won't change anything else nor suffer any compatibility issues.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This kills the following sparse warnings:

fs/nilfs2/segment.c:567:28: warning: symbol 'nilfs_sc_file_ops' was not declared. Should it be static?
fs/nilfs2/segment.c:617:28: warning: symbol 'nilfs_sc_dat_ops' was not declared. Should it be static?
fs/nilfs2/segment.c:625:28: warning: symbol 'nilfs_sc_dsync_ops' was not declared. Should it be static?
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

The implementation of persistent object allocator (alloc.c) is poorly
documented.  This adds kernel doc style comments on that functions.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

In nilfs_segctor_thread(), timer is a local variable allocated on stack. Its
address can't be set to sci->sc_timer and passed in several procedures.

It works now by chance, just because other procedures are called by
nilfs_segctor_thread() directly or indirectly and the stack hasn't been
deallocated yet.
Signed-off-by: NLi Hong <lihong.hi@gmail.com>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

There are only two lines of code in nilfs_segctor_init(). From a logic
design view, the first line 'sci->sc_seq_done = sci->sc_seq_request;'
should be put in nilfs_segctor_new(). Even in nilfs_segctor_new(),
this initialization is needless because sci is kzalloc-ed. So
nilfs_segctor_init() is only a wrap call to
nilfs_segctor_start_thread().
Signed-off-by: NLi Hong <lihong.hi@gmail.com>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This adds a field to record the latest checkpoint number in the
nilfs_segment_summary structure.  This will help to recover the latest
checkpoint number from logs on disk.  This field is intended for
crucial cases in which super blocks have lost pointer to the latest
log.

Even though this will change the disk format, both backward and
forward compatibility is preserved by a size field prepared in the
segment summary header.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

Printing a message after loading a file system is a practice. Add this to
provide a better user-friendly experience.
Signed-off-by: NLi Hong <lihong.hi@gmail.com>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This cleanup patch gives several improvements:

 - Moving all kmem_cache_{create_destroy} calls into one place, which removes
 some small function calls, cleans up error check code and clarify the logic.

 - Mark all initial code in __init section.

 - Remove some very obvious comments.

 - Adjust some declarations.

 - Fix some space-tab issues.
Signed-off-by: NLi Hong <lihong.hi@gmail.com>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This moves out checksum routines in log writer to segbuf.c for
cleanup.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This moves a pointer to buffer storing super root block to each log
buffer from nilfs_sc_info struct for simplicity.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

Like ext3, nilfs has 'errors' mount option to allow specifying desired
behavior on severe errors.

Currently, the default action is 'errors=continue' and has potential
to advance filesystem corruption for severe errors.

This will change the action to 'errors=remount-ro' to avoid the issue.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs_btree_release_path() and nilfs_btree_free_path() are bound into each other
tightly. Make them into one procedure to clearify the logic and avoid some
misusages.
Signed-off-by: NLi Hong <lihong.hi@gmail.com>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

nilfs_btree_alloc_path() and nilfs_btree_init_path() are bound into each other
tightly. Make them into one procedure to clearify the logic and avoid some
misusages.
Signed-off-by: NLi Hong <lihong.hi@gmail.com>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

As of 32a88aa1, __sync_filesystem() will return 0 if s_bdi is not set.
And nilfs does not set s_bdi anywhere.  I noticed this problem by the
warning introduced by the recent commit 5129a469 ("Catch filesystem
lacking s_bdi").

 WARNING: at fs/super.c:959 vfs_kern_mount+0xc5/0x14e()
 Hardware name: PowerEdge 2850
 Modules linked in: nilfs2 loop tpm_tis tpm tpm_bios video shpchp pci_hotplug output dcdbas
 Pid: 3773, comm: mount.nilfs2 Not tainted 2.6.34-rc6-debug #38
 Call Trace:
  [<c1028422>] warn_slowpath_common+0x60/0x90
  [<c102845f>] warn_slowpath_null+0xd/0x10
  [<c1095936>] vfs_kern_mount+0xc5/0x14e
  [<c1095a03>] do_kern_mount+0x32/0xbd
  [<c10a811e>] do_mount+0x671/0x6d0
  [<c1073794>] ? __get_free_pages+0x1f/0x21
  [<c10a684f>] ? copy_mount_options+0x2b/0xe2
  [<c107b634>] ? strndup_user+0x48/0x67
  [<c10a81de>] sys_mount+0x61/0x8f
  [<c100280c>] sysenter_do_call+0x12/0x32

This ensures to set s_bdi for nilfs and fixes the sync silent failure.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: NJens Axboe <jens.axboe@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After merging the block tree, today's linux-next build (powerpc ppc64_defconfig)
failed like this:

fs/nilfs2/the_nilfs.c: In function 'nilfs_discard_segments':
fs/nilfs2/the_nilfs.c:673: error: 'DISCARD_FL_BARRIER' undeclared (first use in this function)

Caused by commit fbd9b09a ("blkdev:
generalize flags for blkdev_issue_fn functions") interacting with commit
e902ec99 ("nilfs2: issue discard request
after cleaning segments") (which netered Linus' tree on about March 4 -
before v2.6.34-rc1).
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Fixes the typo found in a warning message of a persistent object
allocator function.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

`make CONFIG_NILFS2_FS=m M=fs/nilfs2/` will give the following warnings:

fs/nilfs2/btree.c: In function 'nilfs_btree_propagate':
fs/nilfs2/btree.c:1882: warning: 'maxlevel' may be used uninitialized in this function
fs/nilfs2/btree.c:1882: note: 'maxlevel' was declared here

Set maxlevel = 0 to fix it.
Signed-off-by: NLi Hong <lihong.hi@gmail.com>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

(void * __user *) should be (void __user *)
Signed-off-by: NLi Hong <lihong.hi@gmail.com>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

nilfs_wait_on_logs has a potential to slip out before completion of
all bio requests when it met an error.  This synchronization fault may
cause unexpected results, for instance, violative access to freed
segment buffers from an end-bio callback routine.

This fixes the issue by ensuring that nilfs_wait_on_logs waits all
given logs.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

According to the report from Andreas Beckmann (Message-ID:
<4BA54677.3090902@abeckmann.de>), nilfs in 2.6.33 kernel got stuck
after a disk full error.

This turned out to be a regression by log writer updates merged at
kernel 2.6.33.  nilfs_segctor_abort_construction, which is a cleanup
function for erroneous cases, was skipping writeback completion for
some logs.

This fixes the bug and would resolve the hang issue.
Reported-by: NAndreas Beckmann <debian@abeckmann.de>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: stable <stable@kernel.org>                     [2.6.33.x]

Andreas Beckmann gave me a report that nilfs logged the following
warnings when it got a disk full:

  nilfs_sufile_do_cancel_free: segment 0 must be clean
  nilfs_sufile_do_cancel_free: segment 1 must be clean

These arise from a duplicate call to nilfs_segctor_cancel_freev in an
error path of log writer.  This will fix the issue.
Reported-by: NAndreas Beckmann <debian@abeckmann.de>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This kills the following checkpatch warnings:

 WARNING: unnecessary whitespace before a quoted newline
 #869: FILE: super.c:869:
 +     	           "remount to a different snapshot. \n",

 WARNING: unnecessary whitespace before a quoted newline
 #389: FILE: the_nilfs.c:389:
 +     	    printk(KERN_ERR "NILFS: too short segment. \n");
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This kills the following checkpatch warnings:

 WARNING: please, no space before tabs
 #74: FILE: segment.h:74:
 +^Iunsigned ^I^Iflags;$

 WARNING: please, no space before tabs
 #35: FILE: segbuf.c:35:
 +^Iint ^I^I^Istart, end; /* The region to be submitted */$
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This fixes various typos I found in comments of nilfs2.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>