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>

23 files changed, 19 insertions, 4 deletions

diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index 6df6d6ed74fd..6ef7b26724ec 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -22,6 +22,7 @@
 #include <linux/posix_acl_xattr.h>
 #include <linux/posix_acl.h>
 #include <linux/sched.h>
+#include <linux/slab.h>
 
 #include "ctree.h"
 #include "btrfs_inode.h"
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index c0861e781cdb..462859a30141 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/kthread.h>
+#include <linux/slab.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/freezer.h>
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 28b92a7218ab..629880ec8ac4 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -32,6 +32,7 @@
 #include <linux/writeback.h>
 #include <linux/bit_spinlock.h>
 #include <linux/pagevec.h>
+#include <linux/slab.h>
 #include "compat.h"
 #include "ctree.h"
 #include "disk-io.h"
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index c4bc570a396e..8e29260cd0bb 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/slab.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0af2e3868573..8a6518a3f041 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -26,6 +26,7 @@
 #include <linux/completion.h>
 #include <linux/backing-dev.h>
 #include <linux/wait.h>
+#include <linux/slab.h>
 #include <asm/kmap_types.h>
 #include "extent_io.h"
 #include "extent_map.h"
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 84e6781413b1..902ce507c4e3 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/slab.h>
 #include <linux/sort.h>
 #include "ctree.h"
 #include "delayed-ref.h"
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 11d0ad30e203..e57ded75d910 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -27,6 +27,7 @@
 #include <linux/kthread.h>
 #include <linux/freezer.h>
 #include <linux/crc32c.h>
+#include <linux/slab.h>
 #include "compat.h"
 #include "ctree.h"
 #include "disk-io.h"
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1727b26fb194..fa2907d531a2 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -22,6 +22,7 @@
 #include <linux/sort.h>
 #include <linux/rcupdate.h>
 #include <linux/kthread.h>
+#include <linux/slab.h>
 #include "compat.h"
 #include "hash.h"
 #include "ctree.h"
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index c99121ac5d6b..0adceb525167 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2,7 +2,6 @@
 #include <linux/slab.h>
 #include <linux/bio.h>
 #include <linux/mm.h>
-#include <linux/gfp.h>
 #include <linux/pagemap.h>
 #include <linux/page-flags.h>
 #include <linux/module.h>
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 28d87ba60ce8..454ca52d6451 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -1,5 +1,4 @@
 #include <linux/err.h>
-#include <linux/gfp.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 9b99886562d0..54a255065aa3 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/bio.h>
+#include <linux/slab.h>
 #include <linux/pagemap.h>
 #include <linux/highmem.h>
 #include "ctree.h"
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index ee3323c7fc1c..29ff749ff4ca 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -28,6 +28,7 @@
 #include <linux/writeback.h>
 #include <linux/statfs.h>
 #include <linux/compat.h>
+#include <linux/slab.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index dd831ed31eea..f488fac04d99 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -18,6 +18,7 @@
 
 #include <linux/pagemap.h>
 #include <linux/sched.h>
+#include <linux/slab.h>
 #include <linux/math64.h>
 #include "ctree.h"
 #include "free-space-cache.h"
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 02bb099845fd..2fe494c84e60 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -36,6 +36,7 @@
 #include <linux/xattr.h>
 #include <linux/posix_acl.h>
 #include <linux/falloc.h>
+#include <linux/slab.h>
 #include "compat.h"
 #include "ctree.h"
 #include "disk-io.h"
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 2845c6ceecd2..9b3d73a0fdc8 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -39,6 +39,7 @@
 #include <linux/security.h>
 #include <linux/xattr.h>
 #include <linux/vmalloc.h>
+#include <linux/slab.h>
 #include "compat.h"
 #include "ctree.h"
 #include "disk-io.h"
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c
index 1c36e5cd8f55..6151f2ea38bb 100644
--- a/fs/btrfs/locking.c
+++ b/fs/btrfs/locking.c
@@ -16,7 +16,6 @@
  * Boston, MA 021110-1307, USA.
  */
 #include <linux/sched.h>
-#include <linux/gfp.h>
 #include <linux/pagemap.h>
 #include <linux/spinlock.h>
 #include <linux/page-flags.h>
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index a8ffecd0b491..ecb22ff7d1fd 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -16,7 +16,6 @@
  * Boston, MA 021110-1307, USA.
  */
 
-#include <linux/gfp.h>
 #include <linux/slab.h>
 #include <linux/blkdev.h>
 #include <linux/writeback.h>
diff --git a/fs/btrfs/ref-cache.c b/fs/btrfs/ref-cache.c
index d0cc62bccb94..a97314cf6bd6 100644
--- a/fs/btrfs/ref-cache.c
+++ b/fs/btrfs/ref-cache.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/slab.h>
 #include <linux/sort.h>
 #include "ctree.h"
 #include "ref-cache.h"
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 0b23942cbc0d..e558dd941ded 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -21,6 +21,7 @@
 #include <linux/writeback.h>
 #include <linux/blkdev.h>
 #include <linux/rbtree.h>
+#include <linux/slab.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 9ac612e6ca60..693a664318fe 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -38,6 +38,7 @@
 #include <linux/namei.h>
 #include <linux/miscdevice.h>
 #include <linux/magic.h>
+#include <linux/slab.h>
 #include "compat.h"
 #include "ctree.h"
 #include "disk-io.h"
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 2d654c1c794d..c0d0e3e7bc63 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/fs.h>
+#include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/writeback.h>
 #include <linux/pagemap.h>
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 1255fcc8ade5..af57dd2b43d4 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/sched.h>
+#include <linux/slab.h>
 #include "ctree.h"
 #include "transaction.h"
 #include "disk-io.h"
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9df8e3f1ccab..1692ec9cd7b0 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -17,6 +17,7 @@
  */
 #include <linux/sched.h>
 #include <linux/bio.h>
+#include <linux/slab.h>
 #include <linux/buffer_head.h>
 #include <linux/blkdev.h>
 #include <linux/random.h>