staging: zsmalloc: zsmalloc: use unsigned long instead of void *

We should use unsigned long as handle instead of void * to avoid any
confusion. Without this, users may just treat zs_malloc return value as
a pointer and try to deference it.

This patch passed compile test(zram, zcache and ramster) and zram is
tested on qemu.

changelog
  * from v2
	- remove hval pointed out by Nitin
	- based on next-20120607
  * from v1
	- change zcache's zv_create return value
	- baesd on next-20120604

Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:

	drivers/staging/zsmalloc/zsmalloc-main.c
	drivers/staging/zsmalloc/zsmalloc.h
zram_drv: fix merge error from c234434835b1f4bad9bdbae6710044cba387c9e5

Signed-off-by: faux123 <reioux@gmail.com>
staging: zram: fix random data read

fd1a30de makes a bug that it uses (struct page *) as zsmalloc's handle
although it's a uncompressed page so that it can access random page,
return random data or even crashed by get_first_page in zs_map_object.

Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:

	drivers/staging/zram/zram_drv.c
Modified for SGS4 Kernel

Signed-off-by: faux123 <reioux@gmail.com>
staging: zram: remove special handle of uncompressed page

xvmalloc can't handle PAGE_SIZE page so that zram have to
handle it specially but zsmalloc can do it so let's remove
unnecessary special handling code.

Quote from Nitin
"I think page vs handle distinction was added since xvmalloc could not
handle full page allocation. Now that zsmalloc allows full page
allocation, we can just use it for both cases. This would also allow
removing the ZRAM_UNCOMPRESSED flag. The only downside will be slightly
slower code path for full page allocation but this event is anyways
supposed to be rare, so should be fine."

1. This patch reduces code very much.

 drivers/staging/zram/zram_drv.c   |  104 +++++--------------------------------
 drivers/staging/zram/zram_drv.h   |   17 +-----
 drivers/staging/zram/zram_sysfs.c |    6 +--
 3 files changed, 15 insertions(+), 112 deletions(-)

2. change pages_expand with bad_compress so it can count
   bad compression(above 75%) ratio.

3. remove zobj_header which is for back-reference for defragmentation
   because firstly, it's not used at the moment and zsmalloc can't handle
   bigger size than PAGE_SIZE so zram can't do it any more without redesign.

Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:

	drivers/staging/zram/zram_drv.c
modified for SGS 4

Signed-off-by: faux123 <reioux@gmail.com>
staging: zram: conventions pr_warning -> pr_warn()

Porting zram to use the pr_warn() function instead of the deprecated
pr_warning().

Signed-off-by: Sam Hansen <solid.se7en@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
staging: zram: conventions, __aligned() attribute

Using the __aligned() attribute in favor of __attribute__((aligned(size)))

Signed-off-by: Sam Hansen <solid.se7en@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
staging: zram/zcache: swtich Kconfig dependency from X86 to ZSMALLOC

This patch switches zcache and zram dependency to ZSMALLOC
rather than X86.  There is no net change since ZSMALLOC
depends on X86, however, this prevent further changes to
these files as zsmalloc dependencies change.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:

	drivers/staging/zram/Kconfig

Conflicts:
	drivers/staging/zcache/Kconfig
staging: zsmalloc: add mapping modes

This patch improves mapping performance in zsmalloc by getting
usage information from the user in the form of a "mapping mode"
and using it to avoid unnecessary copying for objects that span
pages.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:

	drivers/staging/zram/zram_drv.c

Conflicts:
	drivers/staging/zcache/zcache-main.c
staging: zram: correct obsolete comment on max_zpage_size

Zram doesn't use xv_malloc any more so it doesn't have
limitation about zobj_header.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
staging: zram: Fix handling of incompressible pages

Change 130f315a (staging: zram: remove special handle of uncompressed page)
introduced a bug in the handling of incompressible pages which resulted in
memory allocation failure for such pages.

When a page expands on compression, say from 4K to 4K+30, we were trying to
do zsmalloc(pool, 4K+30). However, the maximum size which zsmalloc can
allocate is PAGE_SIZE (for obvious reasons), so such allocation requests
always return failure (0).

For a page that has compressed size larger than the original size (this may
happen with already compressed or random data), there is no point storing
the compressed version as that would take more space and would also require
time for decompression when needed again. So, the fix is to store any page,
whose compressed size exceeds a threshold (max_zpage_size), as-it-is i.e.
without compression.  Memory required for storing this uncompressed page can
then be requested from zsmalloc which supports PAGE_SIZE sized allocations.

Lastly, the fix checks that we do not attempt to "decompress" the page which
we stored in the uncompressed form -- we just memcpy() out such pages.

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Reported-by: viechweg@gmail.com
Reported-by: paerley@gmail.com
Reported-by: wu.tommy@gmail.com
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
staging: zram: factor-out zram_decompress_page() function

zram_bvec_read() shared decompress functionality with zram_read_before_write() function.
Factor-out and make commonly used zram_decompress_page() function, which also simplified
error handling in zram_bvec_read().

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:

	drivers/staging/zram/zram_drv.c
staging: zram: handle mem suffixes in disk size zram_sysfs parameter

Use memparse() to allow mem suffixes in disksize sysfs number.
Examples:
    echo 256K > /sys/block/zram0/disksize
    echo 512M > /sys/block/zram0/disksize
    echo 1G > /sys/block/zram0/disksize

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
staging: Add angle bracket before and after the URL

Add missing angle bracket before and after the URL.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
staging: zram: fix invalid memory references during disk write

Fixes a bug introduced by commit c8f2f0db1 ("zram: Fix handling
of incompressible pages") which caused invalid memory references
during disk write. Invalid references could occur in two cases:
 - Incoming data expands on compression: In this case, reference was
made to kunmap()'ed bio page.
 - Partial (non PAGE_SIZE) write with incompressible data: In this
case, reference was made to a kfree()'ed buffer.

Fixes bug 50081:
https://bugzilla.kernel.org/show_bug.cgi?id=50081

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Cc: stable <stable@vger.kernel.org>
Reported-by: Mihail Kasadjikov <hamer.mk@gmail.com>
Reported-by: Tomas M <tomas@slax.org>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
staging: zram: simplify num_devices paramater

Simplify dealing with num_devices when initializing zram.
Also cleanup some of the output messages.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
zram_drv: sync with kernel.org

sync point @ 8f5f90a872c38b4e78f3cc95e8a25434b98e4db2

Signed-off-by: faux123 <reioux@gmail.com>