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: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

12 files changed, 12 insertions, 0 deletions

diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index 8618d8996fea..6d88544b677f 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -5,6 +5,7 @@
 #include <linux/module.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <linux/gfp.h>
 
 #include "blk.h"
 
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 4b686ad08eaa..5fe03def34b2 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -15,6 +15,7 @@
 #include <linux/kdev_t.h>
 #include <linux/module.h>
 #include <linux/err.h>
+#include <linux/slab.h>
 #include "blk-cgroup.h"
 
 static DEFINE_SPINLOCK(blkio_list_lock);
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 96e83c2bdb94..edce1ef7933d 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -24,6 +24,7 @@
 #include <linux/mempool.h>
 #include <linux/bio.h>
 #include <linux/scatterlist.h>
+#include <linux/slab.h>
 
 #include "blk.h"
 
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 3f65c8aadb2f..d22c4c55c406 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -7,6 +7,7 @@
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 #include <linux/bootmem.h>	/* for max_pfn/max_low_pfn */
+#include <linux/slab.h>
 
 #include "blk.h"
 
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 31e7a9375c13..d9a9db5f0a2b 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -9,6 +9,7 @@
 #include <linux/bootmem.h>	/* for max_pfn/max_low_pfn */
 #include <linux/gcd.h>
 #include <linux/jiffies.h>
+#include <linux/gfp.h>
 
 #include "blk.h"
 
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 2ae2cb3f362f..c2b821fa324a 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -2,6 +2,7 @@
  * Functions related to sysfs handling
  */
 #include <linux/kernel.h>
+#include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
diff --git a/block/blk-tag.c b/block/blk-tag.c
index 6b0f52c20964..ece65fc4c79b 100644
--- a/block/blk-tag.c
+++ b/block/blk-tag.c
@@ -5,6 +5,7 @@
 #include <linux/module.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <linux/slab.h>
 
 #include "blk.h"
 
diff --git a/block/bsg.c b/block/bsg.c
index 46597a6bd112..82d58829ba59 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -21,6 +21,7 @@
 #include <linux/idr.h>
 #include <linux/bsg.h>
 #include <linux/smp_lock.h>
+#include <linux/slab.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_ioctl.h>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index dee9d9378fee..fc98a48554fd 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -7,6 +7,7 @@
  *  Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
  */
 #include <linux/module.h>
+#include <linux/slab.h>
 #include <linux/blkdev.h>
 #include <linux/elevator.h>
 #include <linux/jiffies.h>
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index 4eb8e9ea4af5..f26051f44681 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -6,6 +6,7 @@
 #include <linux/elevator.h>
 #include <linux/fd.h>
 #include <linux/hdreg.h>
+#include <linux/slab.h>
 #include <linux/syscalls.h>
 #include <linux/smp_lock.h>
 #include <linux/types.h>
diff --git a/block/ioctl.c b/block/ioctl.c
index be48ea51faee..8905d2a2a717 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -1,5 +1,6 @@
 #include <linux/capability.h>
 #include <linux/blkdev.h>
+#include <linux/gfp.h>
 #include <linux/blkpg.h>
 #include <linux/hdreg.h>
 #include <linux/backing-dev.h>
diff --git a/block/noop-iosched.c b/block/noop-iosched.c
index 3a0d369d08c7..232c4b38cd37 100644
--- a/block/noop-iosched.c
+++ b/block/noop-iosched.c
@@ -5,6 +5,7 @@
 #include <linux/elevator.h>
 #include <linux/bio.h>
 #include <linux/module.h>
+#include <linux/slab.h>
 #include <linux/init.h>
 
 struct noop_data {