When the 1st LEB was unmapped and written but 2nd LEB not,
the master node recovery doesn't succeed after power cut.
We see following error when mounting UBIFS partition on NOR
flash:

UBIFS error (pid 1137): ubifs_recover_master_node: failed to recover master node

Correct 2nd master node offset check is needed to fix the
problem. If the 2nd master node is at the end in the 2nd LEB,
first master node is used for recovery. When checking for this
condition we should check whether the master node is exactly at
the end of the LEB (without remaining empty space) or whether
it is followed by an empty space less than the master node size.

Artem: when the error happened, offs2 = 261120, sz = 512, c->leb_size = 262016.
Signed-off-by: NAnatolij Gustschin <agust@denx.de>
Signed-off-by: NArtem Bityutskiy <dedekind1@gmail.com>

This patch cleans-up and improves the power cut testing:

1. Kill custom 'simple_random()' function and use 'random32()' instead.
2. Make timeout larger
3. When cutting the buffer - fill the end with random data sometimes, not
   only with 0xFFs.
4. Some times cut in the middle of the buffer, not always at the end.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Since the recovery testing is effectively about emulating power cuts by UBIFS,
use "power cut" as the base term for all the related variables and name them
correspondingly. This is just a minor clean-up for the sake of readability.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This is a clean-up of the power-cut emulation code - remove the custom list of
superblocks which we maintained to find the superblock by the UBI volume
descriptor. We do not need that crud any longer, because now we can get the
superblock as a function argument.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Now when we use UBIFS helpers for all the I/O, we can remove the horrible hack
of re-defining UBI I/O functions.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Switch the rest of direct UBI calls to UBIFS helper functions.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Stop using 'ubi_leb_write()' directly and switch to the 'ubifs_leb_write()'
helper.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Instead of using 'ubi_read()' function directly, used the 'ubifs_leb_read()'
helper function instead. This allows to get rid of several redundant error
messages and make sure that we always have a stack dump on read errors.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Introduce the following I/O helper functions: 'ubifs_leb_read()',
'ubifs_leb_write()', 'ubifs_leb_change()', 'ubifs_leb_unmap()',
'ubifs_leb_map()', 'ubifs_is_mapped().

The idea is to wrap all UBI I/O functions in order to encapsulate various
assertions and error path handling (error message, stack dump, switching to R/O
mode). And there are some other benefits of this which will be used in the
following patches.

This patch does not switch whole UBIFS to use these functions yet.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When switching to R/O mode due to an I/O error, always dump the stack, not only
when debugging is enabled.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch contains several minor clean-up and preparational cahnges.

1. Remove 'dbg_read()', 'dbg_write()', 'dbg_change()', and 'dbg_leb_erase()'
   functions as they are not used.
2. Remove 'dbg_leb_read()' and 'dbg_is_mapped()' as they are not really needed,
   it is fine to let reads go through in failure mode.
3. Rename 'offset' argument to 'offs' to be consistent with the rest of UBIFS
   code.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Now we have per-FS (superblock) debugfs knobs, but they have one drawback - you
have to first mount the FS and only after this you can switch self-checks
on/off. But often we want to have the checks enabled during the mount.
Introduce global debugging knobs for this purpose.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Separate out pieces of code from the debugfs file read/write functions and
create separate 'interpret_user_input()'/'provide_user_output()' helpers. These
helpers will be needed in one of the following patches, so this is just a
preparational change.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Move 'dbg_debugfs_init()' and 'dbg_debugfs_exit()' functions which initialize
debugfs for whole UBIFS subsystem below the code which initializes debugfs for
a particular UBIFS instance. And do the same for 'ubifs_debugging_init()' and
'ubifs_debugging_exit()' functions. This layout is a bit better for the next
patches, so this is just a preparation.

Also, rename 'open_debugfs_file()' into 'dfs_file_open()' for consistency.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When we are testing UBIFS recovery, it is better to print in which eraseblock
we are going to fail. Currently UBIFS prints it only if recovery debugging
messages are enabled, but this is not very practical. So change 'dbg_rcvry()'
messages to 'ubifs_warn()' messages.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

UBIFS has many built-in self-check functions which can be enabled using the
debug_chks module parameter or the corresponding sysfs file
(/sys/module/ubifs/parameters/debug_chks). However, this is not flexible enough
because it is not per-filesystem. This patch moves this to debugfs interfaces.

We already have debugfs support, so this patch just adds more debugfs files.
While looking at debugfs support I've noticed that it is racy WRT file-system
unmount, and added a TODO entry for that. This problem has been there for long
time and it is quite standard debugfs PITA. The plan is to fix this later.

This patch is simple, but it is large because it changes many places where we
check if a particular type of checks is enabled or disabled.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

We have too many different debugging checks - lessen the amount by merging all
index-related checks into one. At the same time, move the "force in-the-gap"
test to the "index checks" class, because it is too heavy for the "general"
class.

This patch merges TNC, Old index, and Index size check and calles this just
"index checks".
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch introduces helper functions for all debugging checks, so instead of
doing

if (!(ubifs_chk_flags & UBIFS_CHK_GEN))

we now do

if (!dbg_is_chk_gen(c))

This is a preparation to further changes where the flags will go away, and
we'll need to only change the helper functions, but the code which utilizes
them won't be touched.

At the same time this patch removes 'dbg_force_in_the_gaps()',
'dbg_force_in_the_gaps_enabled()', and dbg_failure_mode helpers for
consistency.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Add 'const struct ubifs_info *c' parameter to 'dbg_check_synced_i_size()'
function because we'll need it in the next patch when we switch to debugfs.
So this patch is just a preparation.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Add 'struct ubifs_info *c' parameter to the 'dbg_check_name()' debugging
function - it will be needed in one of the following commits where we switch to
debugfs. So this is just a preparation.

Mark parameters as 'const' while on it.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Add a couple of comments - while looking into TNC I could not easily figure out
few facts, so it is a good idea to document them in the code.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The UBIFS lpt tree is in many aspects similar to the TNC tree, and we have
similar flags for these trees. And by mistake we use the COW_ZNODE flag for
LPT in some places, instead of the right flag COW_CNODE. And this works
only because these two constants have the same value.

This patch makes all the LPT code to use COW_CNODE and also changes COW_CNODE
constant value to make sure we do not misuse the flags any more.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

We have 3 znode flags: cow, obsolete, dirty. For the last flag we have a
'ubifs_zn_dirty()' helper function, but for the other 2 flags we use
'test_bit()' directly.

This patch makes the situation more consistent and introduces helpers for the
other 2 flags: 'ubifs_zn_cow()' and 'ubifs_zn_obsolete()'.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Remove dead pieces of code under "if (c->min_io_size == 1)" statement -
we never execute it because in UBIFS 'c->min_io_size' is always at least 8.
This are leftovers from old pre-mainline prototype.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Remove unnecessary brackets in "inode->i_flags |= (S_NOCMTIME)" statement to
make the code not look silly.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Instead of using long "(inode->i_mode & S_IFMT) != S_IFREG" expression, use
shorted "!S_ISREG(inode->i_mode)".
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Since this function is not only about size checking, rename it to
'dbg_check_dir()'.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Teach 'dbg_dump_inode()' dump directory entries for directory inodes.
This requires few additional changes:
1. The 'c' argument of 'dbg_dump_inode()' cannot be const any more.
2. Users of 'dbg_dump_inode()' should not have 'tnc_mutex' locked.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When we fail to read a pnode or nnode - print stacktrace if debugging is enabled.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch lessens the 'struct ubifs_debug_info' size by 90 bytes by
allocating less bytes for the debugfs root directory name. It introduces macros
for the name patter an length instead of hard-coding 100 bytes. It also makes
UBIFS use 'snprintf()' and teaches it to gracefully catch situations when the
name array is too short.

Additionally, this patch makes 2 unrelated changes - I just thought they do not
deserve separate commits: simplifies 'ubifs_assert()' for non-debugging case
and makes 'dbg_debugfs_init()' properly verify debugfs return code which may be
an error code or NULL, so we should you 'IS_ERR_OR_NULL()' instead of
'IS_ERR()'.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

If commit failed and it is in broken state, UBIFS switches to R/O mode. Most
operations return -EROFS in this case, except of commit which returns -EINVAL.
Make it return -EROFS too for consistency. This is also important for our power
cut emulation testing.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When auditing the locking in i915_gem.c (for a prospective change which
I then abandoned), I noticed two places where struct_mutex is not held
across GEM object manipulations that would usually require it.

Since one is in initial setup and the other in driver unload, I'm
guessing the mutex is not required for either; but post a patch in case
it is.
Signed-off-by: NHugh Dickins <hughd@google.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The interface to ->truncate_range is changing very slightly: once "tmpfs:
take control of its truncate_range" has been applied, this can be applied.
 For now there is only a slight inefficiency while this remains unapplied,
but it will soon become essential for managing shmem's use of swap.

Change i915_gem_object_truncate() to use shmem_truncate_range() directly:
which should also spare i915 later change if we switch from
inode_operations->truncate_range to file_operations->fallocate.
Signed-off-by: NHugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Soon tmpfs will stop supporting ->readpage and read_cache_page_gfp(): once
"tmpfs: add shmem_read_mapping_page_gfp" has been applied, this patch can
be applied to ease the transition.

Make i915_gem_object_get_pages_gtt() use shmem_read_mapping_page_gfp() in
the one place it's needed; elsewhere use shmem_read_mapping_page(), with
the mapping's gfp_mask properly initialized.

Forget about __GFP_COLD: since tmpfs initializes its pages with memset,
asking for a cold page is counter-productive.

Include linux/shmem_fs.h also in drm_gem.c: with shmem_file_setup() now
declared there too, we shall remove the prototype from linux/mm.h later.
Signed-off-by: NHugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Soon tmpfs will stop supporting ->readpage and read_mapping_page(): once
"tmpfs: add shmem_read_mapping_page_gfp" has been applied, this patch can
be applied to ease the transition.

ttm_tt_swapin() and ttm_tt_swapout() use shmem_read_mapping_page() in
place of read_mapping_page(), since their swap_space has been created with
shmem_file_setup().
Signed-off-by: NHugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fis the warning

  drivers/tty/serial/8250_pci.c:1457: warning: initialization from incompatible pointer type

Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix this section mismatch:

  WARNING: drivers/misc/ioc4.o(.data+0x144): Section mismatch in reference from the variable ioc4_load_modules_work to the function .devinit.text:ioc4_load_modules()
  The variable ioc4_load_modules_work references
  the function __devinit ioc4_load_modules()
  If the reference is valid then annotate the
  variable with __init* or __refdata (see linux/init.h) or name the variable:
  *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

This one is potentially fatal; by the time ioc4_load_modules is invoked
it may already have been freed.  For that reason ioc4_load_modules_work
can't be turned to __devinitdata but also because it's referenced in
ioc4_exit.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Acked-by: NBrent Casavant <bcasavan@sgi.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix this section mismatch:

  WARNING: drivers/leds/leds-lp5523.o(.text+0x12f4): Section mismatch in reference from the function lp5523_probe() to the function .init.text:lp5523_init_led()
  The function lp5523_probe() references
  the function __init lp5523_init_led().
  This is often because lp5523_probe lacks a __init
  annotation or the annotation of lp5523_init_led is wrong.

Fixing this one triggers one more mismatch, fix that one as well.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix this section mismatch:

  WARNING: drivers/leds/leds-lp5521.o(.text+0xf2c): Section mismatch in reference from the function lp5521_probe() to the function .init.text:lp5521_init_led()
  The function lp5521_probe() references
  the function __init lp5521_init_led().
  This is often because lp5521_probe lacks a __init
  annotation or the annotation of lp5521_init_led is wrong.

Fixing this mismatch triggers one more mismatch, fix that one as well.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>