linux-toradex.git/fs/fscache, branch v2.6.35.1

FS-Cache: Remove unneeded null checks

2010-06-01T20:32:11+00:00

fscache_write_op() makes unnecessary checks of the page variable to see if it
is NULL.  It can't be NULL at those points as the kernel would already have
crashed a little higher up where we examined page->index.

Furthermore, unless radix_tree_gang_lookup_tag() can return 1 but no page, a
NULL pointer crash should not be encountered there as we can only get there if
r_t_g_l_t() returned 1.

Signed-off-by: Dan Carpenter 
Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

fs/fscache/object-list.c: fix warning on 32-bit

2010-05-26T15:19:23+00:00

fs/fscache/object-list.c: In function 'fscache_objlist_lookup':
fs/fscache/object-list.c:105: warning: cast to pointer from integer of different size

Acked-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs-cache: order the debugfs stats correctly

2010-04-07T15:38:05+00:00

Order the debugfs statistics correctly.  The values displayed through a
seq_printf() statement should be in the same order as the names in the
format string.

In the 'Lookups' line, objects created ('crt=') and lookups timed out
('tmo=') have their values transposed.

Signed-off-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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

2010-03-30T13:02:32+00:00

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: Tejun Heo 
Guess-its-ok-by: Christoph Lameter 
Cc: Ingo Molnar 
Cc: Lee Schermerhorn

SLOW_WORK: CONFIG_SLOW_WORK_PROC should be CONFIG_SLOW_WORK_DEBUG

2010-03-29T16:14:47+00:00

CONFIG_SLOW_WORK_PROC was changed to CONFIG_SLOW_WORK_DEBUG, but not in all
instances.  Change the remaining instances.  This makes the debugfs file
display the time mark and the owner's description again.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

fscache: add missing unlock

2010-03-24T23:49:21+00:00

Sparse complained about this missing spin_unlock()

Signed-off-by: Dan Carpenter 
Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

FS-Cache: Remove the EXPERIMENTAL flag

2010-03-08T15:32:34+00:00

Remove the EXPERIMENTAL flag from FS-Cache so that Ubuntu can make use of the
facility.

Signed-off-by: Christian Kujau 
Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

FS-Cache: Avoid maybe-used-uninitialised warning on variable

2009-12-16T15:20:13+00:00

Andrew Morton's compiler sees the following warning in FS-Cache:

fs/fscache/object-list.c: In function 'fscache_objlist_lookup':
fs/fscache/object-list.c:94: warning: 'obj' may be used uninitialized in this function

which my compiler doesn't.  This is a false positive as obj can only be
used in the comparison against minobj if minobj has been set to something
other than NULL, but for that to happen, obj has to be first set to
something.

Deal with this by preclearing obj too.

Reported-by: Andrew Morton 
Signed-off-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

FS-Cache: Provide nop fscache_stat_d() if CONFIG_FSCACHE_STATS=n

2009-11-20T21:50:44+00:00

Provide nop fscache_stat_d() macro if CONFIG_FSCACHE_STATS=n lest errors like
the following occur:

	fs/fscache/cache.c: In function 'fscache_withdraw_cache':
	fs/fscache/cache.c:386: error: implicit declaration of function 'fscache_stat_d'
	fs/fscache/cache.c:386: error: 'fscache_n_cop_sync_cache' undeclared (first use in this function)
	fs/fscache/cache.c:386: error: (Each undeclared identifier is reported only once
	fs/fscache/cache.c:386: error: for each function it appears in.)
	fs/fscache/cache.c:392: error: 'fscache_n_cop_dissociate_pages' undeclared (first use in this function)

Signed-off-by: David Howells

CacheFiles: Catch an overly long wait for an old active object

2009-11-19T18:12:05+00:00

Catch an overly long wait for an old, dying active object when we want to
replace it with a new one.  The probability is that all the slow-work threads
are hogged, and the delete can't get a look in.

What we do instead is:

 (1) if there's nothing in the slow work queue, we sleep until either the dying
     object has finished dying or there is something in the slow work queue
     behind which we can queue our object.

 (2) if there is something in the slow work queue, we return ETIMEDOUT to
     fscache_lookup_object(), which then puts us back on the slow work queue,
     presumably behind the deletion that we're blocked by.  We are then
     deferred for a while until we work our way back through the queue -
     without blocking a slow-work thread unnecessarily.

A backtrace similar to the following may appear in the log without this patch:

	INFO: task kslowd004:5711 blocked for more than 120 seconds.
	"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
	kslowd004     D 0000000000000000     0  5711      2 0x00000080
	 ffff88000340bb80 0000000000000046 ffff88002550d000 0000000000000000
	 ffff88002550d000 0000000000000007 ffff88000340bfd8 ffff88002550d2a8
	 000000000000ddf0 00000000000118c0 00000000000118c0 ffff88002550d2a8
	Call Trace:
	 [] ? trace_hardirqs_on+0xd/0xf
	 [] ? cachefiles_wait_bit+0x0/0xd [cachefiles]
	 [] cachefiles_wait_bit+0x9/0xd [cachefiles]
	 [] __wait_on_bit+0x43/0x76
	 [] ? ext3_xattr_get+0x1ec/0x270
	 [] out_of_line_wait_on_bit+0x69/0x74
	 [] ? cachefiles_wait_bit+0x0/0xd [cachefiles]
	 [] ? wake_bit_function+0x0/0x2e
	 [] cachefiles_mark_object_active+0x203/0x23b [cachefiles]
	 [] cachefiles_walk_to_object+0x558/0x827 [cachefiles]
	 [] cachefiles_lookup_object+0xac/0x12a [cachefiles]
	 [] fscache_lookup_object+0x1c7/0x214 [fscache]
	 [] fscache_object_state_machine+0xa5/0x52d [fscache]
	 [] fscache_object_slow_work_execute+0x5f/0xa0 [fscache]
	 [] slow_work_execute+0x18f/0x2d1
	 [] slow_work_thread+0x1c5/0x308
	 [] ? autoremove_wake_function+0x0/0x34
	 [] ? slow_work_thread+0x0/0x308
	 [] kthread+0x7a/0x82
	 [] child_rip+0xa/0x20
	 [] ? restore_args+0x0/0x30
	 [] ? kthread+0x0/0x82
	 [] ? child_rip+0x0/0x20
	1 lock held by kslowd004/5711:
	 #0:  (&sb->s_type->i_mutex_key#7/1){+.+.+.}, at: [] cachefiles_walk_to_object+0x1b3/0x827 [cachefiles]

Signed-off-by: David Howells