Revert prior f2fs driver and squash CM updates

This reverts commit fca725fdc877112a5dbe6e3878fc4a651f961f2b.

F2FS: Backport to 3.4

Based off of patches here:
nowcomputing/f2fs-backports#1

Conflicts:
	fs/f2fs/acl.c
	fs/f2fs/file.c
	fs/f2fs/gc.c
	fs/f2fs/gc.h
	fs/f2fs/inode.c
	fs/f2fs/namei.c
	fs/f2fs/super.c

f2fs: Update to version in 3.14

f2fs: introduce __find_rev_next(_zero)_bit

When f2fs_set_bit is used, in a byte MSB and LSB is reversed,
in that case we can use __find_rev_next_bit or __find_rev_next_zero_bit.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
[Jaegeuk Kim: change the function names]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: improve searching speed of __next_free_blkoff

To find a zero bit using the result of OR operation between ckpt_valid_map
and cur_valid_map is more fast than find a zero bit in each bitmap.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
[Jaegeuk Kim: adjust changed function name]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a slab cache entry for small discards

This patch adds a slab cache entry for small discards.

Each entry consists of:

struct discard_entry {
	struct list_head list;	/* list head */
	block_t blkaddr;	/* block address to be discarded */
	int len;		/* # of consecutive blocks of the discard */
};

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add key functions for small discards

This patch adds key functions to activate the small discard feature.

Note that this procedure is conducted during the checkpoint only.

In flush_sit_entries(), when a new dirty sit entry is flushed, f2fs calls
add_discard_addrs() which searches candidates to be discarded.
The candidates should be marked *invalidated* and also previous checkpoint
recognizes it as *valid*.

At the end of a checkpoint procedure, f2fs throws discards based on the
discard entry list.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a sysfs entry to control max_discards

If frequent small discards are issued to the device, the performance would
be degraded significantly.
So, this patch adds a sysfs entry to control the number of discards to be
issued during a checkpoint procedure.

By default, f2fs does not issue any small discards, which means max_discards
is zero.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce f2fs_issue_discard() to clean up

Change log from v1:
 o fix 32bit drops reported by Dan Carpenter

This patch adds f2fs_issue_discard() to clean up blkdev_issue_discard() flows.

Dan carpenter reported:
"block_t is a 32 bit type and sector_t is a 64 bit type.  The upper 32
bits of the sector_t are not used because the shift will wrap."

Bug-Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a tracepoint for f2fs_issue_discard

This patch adds a tracepoint for f2fs_issue_discard.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: use f2fs_put_page to release page for uniform style

We should use f2fs_put_page to release page for uniform style of f2fs code.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: clean up the do_submit_bio flow

This patch introduces PAGE_TYPE_OF_BIO() and cleans up do_submit_bio() with it.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: use sbi->write_mutex for write bios

This patch removes an unnecessary semaphore (i.e., sbi->bio_sem).
There is no reason to use the semaphore when f2fs submits read and write IOs.
Instead, let's use a write mutex and cover the sbi->bio[] by the lock.

Change log from v1:
 o split write_mutex suggested by Chao Yu

Chao described,
"All DATA/NODE/META bio buffers in superblock is protected by
'sbi->write_mutex', but each bio buffer area is independent, So we
should split write_mutex to three for DATA/NODE/META."

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: disable the extent cache ops on high fragmented files

The f2fs manages an extent cache to search a number of consecutive data blocks
very quickly.

However it conducts unnecessary cache operations if the file is highly
fragmented with no valid extent cache.

In such the case, we don't need to handle the extent cache, but just can disable
the cache facility.

Nevertheless, this patch gives one more chance to enable the extent cache.

For example,
1. create a file
2. write data sequentially which produces a large valid extent cache
3. update some data, resulting in a fragmented extent
4. if the fragmented extent is too small, then drop extent cache
5. close the file

6. open the file again
7. give another chance to make a new extent cache
8. write data sequentially again which creates another big extent cache.
...

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce a bio array for per-page write bios

The f2fs has three bio types, NODE, DATA, and META, and manages some data
structures per each bio types.

The codes are a little bit messy, thus, this patch introduces a bio array
which groups individual data structures as follows.

struct f2fs_bio_info {
	struct bio *bio;		/* bios to merge */
	sector_t last_block_in_bio;	/* last block number */
	struct mutex io_mutex;		/* mutex for bio */
};

struct f2fs_sb_info {
	...
	struct f2fs_bio_info write_io[NR_PAGE_TYPE];	/* for write bios */
	...
};

The code changes from this new data structure are trivial.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: convert remove_inode_page to void

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: convert dev_valid_block_count to void

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: convert inc/dec_valid_node_count to inc/dec one count

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: simplify write_orphan_inodes for better readable

Simplify write_orphan_inodes for better readable. Because we hold the
orphan_inode_mutex, so it's safe to use list_for_each_entry instead of
list_for_each_safe.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: move the list_head initialization into the lock protection region

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a new function to support for merging contiguous read

For better read performance, we add a new function to support for merging
contiguous read as the one for write.

v1-->v2:
 o add declarations here as Gu Zheng suggested.
 o use new structure f2fs_bio_info introduced by Jaegeuk Kim.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Acked-by: Gu Zheng <guz.fnst@cn.fujitsu.com>

f2fs: merge read IOs at ra_nat_pages()

Change log from v1:
  o add mark_page_accessed() not to reclaim the nat pages.

This patch changes the policy of submitting read bios at ra_nat_pages.

Previously, f2fs submits small read bios with block plugging.
But, with this patch, f2fs itself merges read bios first and then submits a
large bio, which can reduce the bio handling overheads.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: simplify IS_DATASEG and IS_NODESEG macro

It is not efficient comparing each segment type to find node or data.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
[Jaegeuk Kim: remove unnecessary white spaces]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: adds a tracepoint for submit_read_page

This patch adds a tracepoint for submit_read_page.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: integrate tracepoints of f2fs_submit_read(_write)_page]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: adds a tracepoint for f2fs_submit_read_bio

This patch adds a tracepoint for f2fs_submit_read_bio.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: integrate tracepoints of f2fs_submit_read(_write)_bio]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: read contiguous sit entry pages by merging for mount performance

Previously we read sit entries page one by one, this method lost the chance
of reading contiguous page together. So we read pages as contiguous as
possible for better mount performance.

change log:
 o merge judgements/use 'Continue' or 'Break' instead of 'Goto' as Gu Zheng
   suggested.
 o add mark_page_accessed() before release page to delay VM reclaiming.
 o remove '*order' for simplification of function as Jaegeuk Kim suggested.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: fix a bug on the block address calculation]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid lock debugging overhead

If CONFIG_F2FS_CHECK_FS is unset, we don't need to add any debugging overhead.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a new function: f2fs_reserve_block()

Add the function f2fs_reserve_block() to easily reserve new blocks, and
use it to clean up more codes.

Signed-off-by: Huajun Li <huajun.li@intel.com>
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Weihong Xu <weihong.xu@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add detailed information of bio types in the tracepoints

This patch inserts information of bio types in more detail.
So, we can now see REQ_META and REQ_PRIO too.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: send REQ_META or REQ_PRIO when reading meta area

Let's send REQ_META or REQ_PRIO when reading meta area such as NAT/SIT
etc.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add flags and helpers to support inline data

Add new inode flags F2FS_INLINE_DATA and FI_INLINE_DATA to indicate
whether the inode has inline data.

Inline data makes use of inode block's data indices region to save small
file. Currently there are 923 data indices in an inode block. Since
inline xattr has made use of the last 50 indices to save its data, there
are 873 indices left which can be used for inline data. When
FI_INLINE_DATA is set, the layout of inode block's indices region is
like below:

+-----------------+
|                 | Reserved. reserve_new_block() will make use of
| i_addr[0]       | i_addr[0] when we need to reserve a new data block
|                 | to convert inline data into regular one's.
|-----------------|
|                 | Used by inline data. A file whose size is less than
| i_addr[1~872]   | 3488 bytes(~3.4k) and doesn't reserve extra
|                 | blocks by fallocate() can be saved here.
|-----------------|
|                 |
| i_addr[873~922] | Reserved for inline xattr
|                 |
+-----------------+

Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Huajun Li <huajun.li@intel.com>
Signed-off-by: Weihong Xu <weihong.xu@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a new mount option: inline_data

Add a mount option: inline_data. If the mount option is set,
data of New created small files can be stored in their inode.

Signed-off-by: Huajun Li <huajun.li@intel.com>
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Weihong Xu <weihong.xu@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove unnecessary return value

Let's remove the unnecessary return value.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix a potential out of range issue

Fix a potential out of range issue introduced by commit:
22fb72225a
f2fs: simplify write_orphan_inodes for better readable

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: bug fix on bit overflow from 32bits to 64bits

This patch fixes some bit overflows by the shift operations.

Dan Carpenter reported potential bugs on bit overflows as follows.

fs/f2fs/segment.c:910 submit_write_page()
	warn: should 'blk_addr << ((sbi)->log_blocksize - 9)' be a 64 bit type?
fs/f2fs/checkpoint.c:429 get_valid_checkpoint()
	warn: should '1 << ()' be a 64 bit type?
fs/f2fs/data.c:408 f2fs_readpage()
	warn: should 'blk_addr << ((sbi)->log_blocksize - 9)' be a 64 bit type?
fs/f2fs/data.c:457 submit_read_page()
	warn: should 'blk_addr << ((sbi)->log_blocksize - 9)' be a 64 bit type?
fs/f2fs/data.c:525 get_data_block_ro()
	warn: should 'i << blkbits' be a 64 bit type?

Bug-Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove unnecessary condition checks

This patch removes the unnecessary condition checks on:

fs/f2fs/gc.c:667 do_garbage_collect() warn: 'sum_page' isn't an ERR_PTR
fs/f2fs/f2fs.h:795 f2fs_put_page() warn: 'page' isn't an ERR_PTR

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove unneeded code in punch_hole

Because FALLOC_FL_PUNCH_HOLE flag must be ORed with FALLOC_FL_KEEP_SIZE
in fallocate, so we could remove the useless 'keep size' branch code which
will never be excuted in punch_hole.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Fan Li <fanofcode.li@samsung.com>
[Jaegeuk Kim: remove an unnecessary parameter togather]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid to calculate incorrect max orphan number

Because we will write node summaries when do_checkpoint with umount flag,
our number of max orphan blocks should minus NR_CURSEG_NODE_TYPE additional.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Shu Tan <shu.tan@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: correct type of wait in struct bio_private

The void *wait in bio_private is used for waiting completion of checkpoint bio.
So we don't need to use its type as void, but declare it as completion type.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: add description]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: use true and false for boolean variable

The inode_page_locked should be a boolean variable.

struct dnode_of_data {
	struct inode *inode;            /* vfs inode pointer */
	struct page *inode_page;        /* its inode page, NULL is possible */
	struct page *node_page;         /* cached direct node page */
	nid_t nid;                      /* node id of the direct node block */
	unsigned int ofs_in_node;       /* data offset in the node page */
==>	bool inode_page_locked;         /* inode page is locked or not */
	block_t data_blkaddr;           /* block address of the node block */
};

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: add description]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: check return value of f2fs_readpage in find_data_page

We should return error if we do not get an updated page in find_date_page
when f2fs_readpage failed.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: convert recover_orphan_inodes to void

The recover_orphan_inodes() returns no error all the time, so we don't need to
check its errors.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: add description]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove the own bi_private allocation

Previously f2fs allocates its own bi_private data structure all the time even
though we don't use it. But, can we remove this bi_private allocation?

This patch removes such the additional bi_private allocation.

1. Retrieve f2fs_sb_info from its page->mapping->host->i_sb.
 - This removes the usecases of bi_private in end_io.

2. Use bi_private only when we really need it.
 - The bi_private is used only when the checkpoint procedure is conducted.
 - When conducting the checkpoint, f2fs submits a META_FLUSH bio to wait its bio
completion.
 - Since we have no dependancies to remove bi_private now, let's just use
 bi_private pointer as the completion pointer.

Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: refactor bio-related operations

This patch integrates redundant bio operations on read and write IOs.

1. Move bio-related codes to the top of data.c.
2. Replace f2fs_submit_bio with f2fs_submit_merged_bio, which handles read
   bios additionally.
3. Introduce __submit_merged_bio to submit the merged bio.
4. Change f2fs_readpage to f2fs_submit_page_bio.
5. Introduce f2fs_submit_page_mbio to integrate previous submit_read_page and
   submit_write_page.

Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com >
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: readahead contiguous pages for restore_node_summary

If cp has no CP_UMOUNT_FLAG, we will read all pages in whole node segment
one by one, it makes low performance. So let's merge contiguous pages and
readahead for better performance.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: adjust the new bio operations]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove debufs dir if debugfs_create_file() failed

When debugfs_create_file() failed in f2fs_create_root_stats(),
debugfs_root should be remove.

Signed-off-by: Younger Liu <liuyiyang@hisense.com>
Cc: Younger Liu <younger.liucn@gmail.com>
Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: replace the debugfs_root with f2fs_debugfs_root

This minor change for the naming conventions of debugfs_root
to avoid any possible conflicts to the other filesystem.

Signed-off-by: Younger Liu <younger.liucn@gmail.com>
Cc: Younger Liu <younger.liucn@gmail.com>
Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
[Jaegeuk Kim: change the patch name]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: use inner macro GFP_F2FS_ZERO for simplification

Use inner macro GFP_F2FS_ZERO to instead of GFP_NOFS | __GFP_ZERO for
simplification of code.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid unneeded page release for correct _count of page

In find_fsync_dnodes() and recover_data(), our flow is like this:

->f2fs_submit_page_bio()
	-> f2fs_put_page()
		-> page_cache_release()	---- page->_count declined to zero.
->__free_pages()
	-> put_page_testzero() ---- page->_count will be declined again.

We will get a segment fault in put_page_testzero when CONFIG_DEBUG_VM
is on, or return MM with a bad page with wrong _count num.

So let's just release this page.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add unlikely() macro for compiler optimization

As we know, some of our branch condition will rarely be true. So we could add
'unlikely' to let compiler optimize these code, by this way we could drop
unneeded 'jump' assemble code to improve performance.

change log:
 o add *unlikely* as many as possible across the whole source files at once
   suggested by Jaegeuk Kim.

Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add unlikely() macro for compiler more aggressively

This patch adds unlikely() macro into the most of codes.
The basic rule is to add that when:
- checking unusual errors,
- checking page mappings,
- and the other unlikely conditions.

Change log from v1:
 - Don't add unlikely for the NULL test and error test: advised by Andi Kleen.

Cc: Chao Yu <chao2.yu@samsung.com>
Cc: Andi Kleen <andi@firstfloor.org>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: merge pages with the same sync_mode flag

Previously f2fs submits most of write requests using WRITE_SYNC, but f2fs_write_data_pages
submits last write requests by sync_mode flags callers pass.

This causes a performance problem since continuous pages with different sync flags
can't be merged in cfq IO scheduler(thanks yu chao for pointing it out), and synchronous
requests often take more time.

This patch makes the following modifies to DATA writebacks:

1. every page will be written back using the sync mode caller pass.
2. only pages with the same sync mode can be merged in one bio request.

These changes are restricted to DATA pages.Other types of writebacks are modified
To remain synchronous.

In my test with tiotest, f2fs sequence write performance is improved by about 7%-10% ,
and this patch has no obvious impact on other performance tests.

Signed-off-by: Fan Li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: refactor bio->rw handling

This patch introduces f2fs_io_info to mitigate the complex parameter list.

struct f2fs_io_info {
	enum page_type type;		/* contains DATA/NODE/META/META_FLUSH */
	int rw;				/* contains R/RS/W/WS */
	int rw_flag;			/* contains REQ_META/REQ_PRIO */
}

1. f2fs_write_data_pages
 - DATA
 - WRITE_SYNC is set when wbc->WB_SYNC_ALL.

2. sync_node_pages
 - NODE
 - WRITE_SYNC all the time

3. sync_meta_pages
 - META
 - WRITE_SYNC all the time
 - REQ_META | REQ_PRIO all the time

 ** f2fs_submit_merged_bio() handles META_FLUSH.

4. ra_nat_pages, ra_sit_pages, ra_sum_pages
 - META
 - READ_SYNC

Cc: Fan Li <fanofcode.li@samsung.com>
Cc: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix the location of tracepoint

We need to get a trace before submit_bio, since its bi_sector is remapped during
the submit_bio.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: missing kmem_cache_destroy for discard_entry

insmod f2fs.ko is failed after insmod and rmmod firstly.

$ sudo insmod fs/f2fs/f2fs.ko
insmod: error inserting 'fs/f2fs/f2fs.ko': -1 Cannot allocate memory

-- dmesg --
kmem_cache_sanity_check (free_nid): Cache name already exists.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce sysfs entry to control in-place-update policy

This patch introduces new sysfs entries for users to control the policy of
in-place-updates, namely IPU, in f2fs.

Sometimes f2fs suffers from performance degradation due to its out-of-place
update policy that produces many additional node block writes.
If the storage performance is very dependant on the amount of data writes
instead of IO patterns, we'd better drop this out-of-place update policy.

This patch suggests 5 polcies and their triggering conditions as follows.

[sysfs entry name = ipu_policy]

0: F2FS_IPU_FORCE       all the time,
1: F2FS_IPU_SSR         if SSR mode is activated,
2: F2FS_IPU_UTIL        if FS utilization is over threashold,
3: F2FS_IPU_SSR_UTIL    if SSR mode is activated and FS utilization is over
                        threashold,
4: F2FS_IPU_DISABLE    disable IPU. (=default option)

[sysfs entry name = min_ipu_util]

This parameter controls the threshold to trigger in-place-updates.
The number indicates percentage of the filesystem utilization, and used by
F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies.

For more details, see need_inplace_update() in segment.h.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce a new direct_IO write path

Previously, f2fs doesn't support direct IOs with high performance, which throws
every write requests via the buffered write path, resulting in highly
performance degradation due to memory opeations like copy_from_user.

This patch introduces a new direct IO path in which every write requests are
processed by generic blockdev_direct_IO() with enhanced get_block function.

The get_data_block() in f2fs handles:
1. if original data blocks are allocates, then give them to blockdev.
2. otherwise,
  a. preallocate requested block addresses
  b. do not use extent cache for better performance
  c. give the block addresses to blockdev

This policy induces that:
- new allocated data are sequentially written to the disk
- updated data are randomly written to the disk.
- f2fs gives consistency on its file meta, not file data.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: write dirty meta pages collectively

This patch enhances writing dirty meta pages collectively in background.
During the file data writes, it'd better avoid to write small dirty meta pages
frequently.
So let's give a chance to collect a number of dirty meta pages for a while.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: move all the bio initialization into __bio_alloc

Move all the bio initialization into __bio_alloc, and some minor cleanups are
also added.

v3:
  Use 'bool' rather than 'int' as Kim suggested.

v2:
  Use 'is_read' rather than 'rw' as Yu Chao suggested.
  Remove the needless initialization of bio->bi_private.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove the rw_flag domain from f2fs_io_info

When using the f2fs_io_info in the low level, we still need to merge the
rw and rw_flag, so use the rw to hold all the io flags directly,
and remove the rw_flag field.

ps.It is based on the previous patch:
f2fs: move all the bio initialization into __bio_alloc

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: update several comments

Update several comments:
1. use f2fs_{un}lock_op install of mutex_{un}lock_op.
2. update comment of get_data_block().
3. update description of node offset.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid to set wrong pino of inode when rename dir

When we rename a dir to new name which is not exist previous,
we will set pino of parent inode with ino of child inode in f2fs_set_link.
It destroy consistency of pino, it should be fixed.

Thanks for previous work of Shu Tan.

Signed-off-by: Shu Tan <shu.tan@samsung.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: check filename length in recover_dentry

In current flow, we will get Null return value of f2fs_find_entry in
recover_dentry when name.len is bigger than F2FS_NAME_LEN, and then we
still add this inode into its dir entry.
To avoid this situation, we must check filename length before we use it.

Another point is that we could remove the code of checking filename length
In f2fs_find_entry, because f2fs_lookup will be called previously to ensure of
validity of filename length.

V2:
 o add WARN_ON() as Jaegeuk Kim suggested.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce F2FS_INODE macro to get f2fs_inode

This patch introduces F2FS_INODE that returns struct f2fs_inode * from the inode
page.
By using this macro, we can remove unnecessary casting codes like below.

   struct f2fs_inode *ri = &F2FS_NODE(inode_page)->i;
-> struct f2fs_inode *ri = F2FS_INODE(inode_page);

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: should put the dnode when NEW_ADDR is detected

When get_dnode_of_data() in get_data_block() returns a successful dnode, we
should put the dnode.
But, previously, if its data block address is equal to NEW_ADDR, we didn't do
that, resulting in a deadlock condition.
So, this patch splits original error conditions with this case, and then calls
f2fs_put_dnode before finishing the function.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: check the blocksize before calling generic_direct_IO path

The f2fs supports 4KB block size. If user requests dwrite with under 4KB data,
it allocates a new 4KB data block.
However, f2fs doesn't add zero data into the untouched data area inside the
newly allocated data block.

This incurs an error during the xfstest #263 test as follow.

263 12s ... [failed, exit status 1] - output mismatch (see 263.out.bad)
	--- 263.out	2013-03-09 03:37:15.043967603 +0900
	+++ 263.out.bad	2013-12-27 04:20:39.230203114 +0900
	@@ -1,3 +1,976 @@
	QA output created by 263
	fsx -N 10000 -o 8192 -l 500000 -r PSIZE -t BSIZE -w BSIZE -Z
	-fsx -N 10000 -o 128000 -l 500000 -r PSIZE -t BSIZE -w BSIZE -Z
	+fsx -N 10000 -o 8192 -l 500000 -r PSIZE -t BSIZE -w BSIZE -Z
	+truncating to largest ever: 0x12a00
	+truncating to largest ever: 0x75400
	+fallocating to largest ever: 0x79cbf
	...
	(Run 'diff -u 263.out 263.out.bad' to see the entire diff)
	Ran: 263
	Failures: 263
	Failed 1 of 1 tests

It turns out that, when the test tries to write 2KB data with dio, the new dio
path allocates 4KB data block without filling zero data inside the remained 2KB
area. Finally, the output file contains a garbage data for that region.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: convert max_orphans to a field of f2fs_sb_info

Previously, we need to calculate the max orphan num when we try to acquire an
orphan inode, but it's a stable value since the super block was inited. So
converting it to a field of f2fs_sb_info and use it directly when needed seems
a better choose.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: key functions to handle inline data

Functions to implement inline data read/write, and move inline data to
normal data block when file size exceeds inline data limitation.

Signed-off-by: Huajun Li <huajun.li@intel.com>
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Weihong Xu <weihong.xu@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: handle inline data operations

Hook inline data read/write, truncate, fallocate, setattr, etc.

Files need meet following 2 requirement to inline:
 1) file size is not greater than MAX_INLINE_DATA;
 2) file doesn't pre-allocate data blocks by fallocate().

FI_INLINE_DATA will not be set while creating a new regular inode because
most of the files are bigger than ~3.4K. Set FI_INLINE_DATA only when
data is submitted to block layer, ranther than set it while creating a new
inode, this also avoids converting data from inline to normal data block
and vice versa.

While writting inline data to inode block, the first data block should be
released if the file has a block indexed by i_addr[0].

On the other hand, when a file operation is appied to a file with inline
data, we need to test if this file can remain inline by doing this
operation, otherwise it should be convert into normal file by reserving
a new data block, copying inline data to this new block and clear
FI_INLINE_DATA flag. Because reserve a new data block here will make use
of i_addr[0], if we save inline data in i_addr[0..872], then the first
4 bytes would be overwriten. This problem can be avoided simply by
not using i_addr[0] for inline data.

Signed-off-by: Huajun Li <huajun.li@intel.com>
Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com>
Signed-off-by: Weihong Xu <weihong.xu@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: don't need to get f2fs_lock_op for the inline_data test

This patch locates checking the inline_data prior to calling f2fs_lock_op()
in truncate_blocks(), since getting the lock is unnecessary.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: convert inline_data for punch_hole

In the punch_hole(), let's convert inline_data all the time for simplicity and
to avoid potential deadlock conditions.
It is pretty much not a big deal to do this.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: call f2fs_put_page at the error case

In f2fs_write_begin(), if f2fs_conver_inline_data() returns an error like
-ENOSPC, f2fs should call f2fs_put_page().
Otherwise, it is remained as a locked page, resulting in the following bug.

[<ffffffff8114657e>] sleep_on_page+0xe/0x20
[<ffffffff81146567>] __lock_page+0x67/0x70
[<ffffffff81157d08>] truncate_inode_pages_range+0x368/0x5d0
[<ffffffff81157ff5>] truncate_inode_pages+0x15/0x20
[<ffffffff8115804b>] truncate_pagecache+0x4b/0x70
[<ffffffff81158082>] truncate_setsize+0x12/0x20
[<ffffffffa02a1842>] f2fs_setattr+0x72/0x270 [f2fs]
[<ffffffff811cdae3>] notify_change+0x213/0x400
[<ffffffff811ab376>] do_truncate+0x66/0xa0
[<ffffffff811ab541>] vfs_truncate+0x191/0x1b0
[<ffffffff811ab5bc>] do_sys_truncate+0x5c/0xa0
[<ffffffff811ab78e>] SyS_truncate+0xe/0x10
[<ffffffff81756052>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: refactor f2fs_convert_inline_data

Change log from v1:
 o handle NULL pointer of grab_cache_page_write_begin() pointed by Chao Yu.

This patch refactors f2fs_convert_inline_data to check a couple of conditions
internally for deciding whether it needs to convert inline_data or not.

So, the new f2fs_convert_inline_data initially checks:
1) f2fs_has_inline_data(), and
2) the data size to be changed.

If the inode has inline_data but the size to fill is less than MAX_INLINE_DATA,
then we don't need to convert the inline_data with data allocation.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add the number of inline_data files to status info

This patch adds the number of inline_data files into the status information.
Note that the number is reset whenever the filesystem is newly mounted.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add inline_data recovery routine

This patch adds a inline_data recovery routine with the following policy.

[prev.] [next] of inline_data flag
   o       o  -> recover inline_data
   o       x  -> remove inline_data, and then recover data blocks
   x       o  -> remove inline_data, and then recover inline_data
   x       x  -> recover data blocks

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: handle errors correctly during f2fs_reserve_block

The get_dnode_of_data nullifies inode and node page when error is occurred.

There are two cases that passes inode page into get_dnode_of_data().

1. make_empty_dir()
    -> get_new_data_page()
      -> f2fs_reserve_block(ipage)
	-> get_dnode_of_data()

2. f2fs_convert_inline_data()
    -> __f2fs_convert_inline_data()
      -> f2fs_reserve_block(ipage)
	-> get_dnode_of_data()

This patch adds correct error handling codes when get_dnode_of_data() returns
an error.

At first, f2fs_reserve_block() calls f2fs_put_dnode() whenever reserve_new_block
returns an error.
So, the rule of f2fs_reserve_block() is to nullify inode page when there is any
error internally.

Finally, two callers of f2fs_reserve_block() should call f2fs_put_dnode()
appropriately if they got an error since successful f2fs_reserve_block().

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix truncate_partial_nodes bug

The truncate_partial_nodes puts pages incorrectly in the following two cases.
Note that the value for argc 'depth' can only be 2 or 3.
Please see truncate_inode_blocks() and truncate_partial_nodes().

1) An err is occurred in the first 'for' loop
  When err is occurred with depth = 2, pages[0] is invalid, so this page doesn't
  need to be put. There is no problem, however, when depth is 3, it doesn't put
  the pages correctly where pages[0] is valid and pages[1] is invalid.
  In this case, depth is set to 2 (ref to statemnt depth = i + 1), and then
  'goto fail'.
  In label 'fail', for (i = depth - 3; i >= 0; i--) cannot meet the condition
  because i = -1, so pages[0] cann't be put.

2) An err happened in the second 'for' loop
  Now we've got pages[0] with depth = 2, or we've got pages[0] and pages[1]
  with depth = 3. When an err is detected, we need 'goto fail' to put such
  the pages.
  When depth is 2, in label 'fail', for (i = depth - 3; i >= 0; i--) cann't
  meet the condition because i = -1, so pages[0] cann't be put.
  When depth is 3, in label 'fail', for (i = depth - 3; i >= 0; i--) can
  only put pages[0], pages[1] also cann't be put.

Note that 'depth' has been changed before first 'goto fail' (ref to statemnt
depth = i + 1), so passing this modified 'depth' to the tracepoint,
trace_f2fs_truncate_partial_nodes, is also incorrect.

Signed-off-by: Shifei Ge <shifei10.ge@samsung.com>
[Jaegeuk Kim: modify the description and fix one bug]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid to left uninitialized data in page when read inline data

Change log from v1:
 o reduce unneeded memset in __f2fs_convert_inline_data

>From 58796be2bd2becbe8d52305210fb2a64e7dd80b6 Mon Sep 17 00:00:00 2001
From: Chao Yu <chao2.yu@samsung.com>
Date: Mon, 30 Dec 2013 09:21:33 +0800
Subject: [PATCH] f2fs: avoid to left uninitialized data in page when read
 inline data

We left uninitialized data in the tail of page when we read an inline data
page. So let's initialize left part of the page excluding inline data region.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid to read inline data except first page

Here is a case which could read inline page data not from first page.

1. write inline data
2. lseek to offset 4096
3. read 4096 bytes from offset 4096
	(read_inline_data read inline data page to non-first page,
	And previously VFS has add this page to page cache)
4. ftruncate offset 8192
5. read 4096 bytes from offset 4096
	(we meet this updated page with inline data in cache)

So we should leave this page with inited data and uptodate flag
for this case.

Change log from v1:
 o fix a deadlock bug

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: improve write performance under frequent fsync calls

When considering a bunch of data writes with very frequent fsync calls, we
are able to think the following performance regression.

N: Node IO, D: Data IO, IO scheduler: cfq

Issue    pending IOs
	 D1 D2 D3 D4
 D1         D2 D3 D4 N1
 D2            D3 D4 N1 N2
 N1            D3 D4 N2 D1
 --> N1 can be selected by cfq becase of the same priority of N and D.
     Then D3 and D4 would be delayed, resuling in performance degradation.

So, when processing the fsync call, it'd better give higher priority to data IOs
than node IOs by assigning WRITE and WRITE_SYNC respectively.
This patch improves the random wirte performance with frequent fsync calls by up
to 10%.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a sysfs entry to control max_victim_search

Previously during SSR and GC, the maximum number of retrials to find a victim
segment was hard-coded by MAX_VICTIM_SEARCH, 4096 by default.

This number makes an effect on IO locality, when SSR mode is activated, which
results in performance fluctuation on some low-end devices.

If max_victim_search = 4, the victim will be searched like below.
("D" represents a dirty segment, and "*" indicates a selected victim segment.)

 D1 D2 D3 D4 D5 D6 D7 D8 D9
[   *       ]
      [   *    ]
            [         * ]
	                [ ....]

This patch adds a sysfs entry to control the number dynamically through:
  /sys/fs/f2fs/$dev/max_victim_search

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove the needless parameter of f2fs_wait_on_page_writeback

"boo sync" parameter is never referenced in f2fs_wait_on_page_writeback.
We should remove this parameter.

Signed-off-by: Yuan Zhong <yuan.mark.zhong@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: move grabing orphan pages out of protection region

Move grabing orphan block page out of protection region, and grab all
the orphan block pages ahead.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: remove unnecessary code pointed by Chao Yu]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: move alloc new orphan node out of lock protection region

Move alloc new orphan node out of lock protection region.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: use spinlock rather than mutex for better speed

With the 2 previous changes, all the long time operations are moved out
of the protection region, so here we can use spinlock rather than mutex
(orphan_inode_mutex) for lower overhead.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add delimiter to seperate name and value in debug phrase

Support for f2fs-tools/tools/f2stat to monitor
/sys/kernel/debug/f2fs/status

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid f2fs_balance_fs call during pageout

This patch should resolve the following bug.

=========================================================
[ INFO: possible irq lock inversion dependency detected ]
3.13.0-rc5.f2fs+ #6 Not tainted
---------------------------------------------------------
kswapd0/41 just changed the state of lock:
 (&sbi->gc_mutex){+.+.-.}, at: [<ffffffffa030503e>] f2fs_balance_fs+0xae/0xd0 [f2fs]
but this lock took another, RECLAIM_FS-READ-unsafe lock in the past:
 (&sbi->cp_rwsem){++++.?}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
Chain exists of:
  &sbi->gc_mutex --> &sbi->cp_mutex --> &sbi->cp_rwsem

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sbi->cp_rwsem);
                               local_irq_disable();
                               lock(&sbi->gc_mutex);
                               lock(&sbi->cp_mutex);
  <Interrupt>
    lock(&sbi->gc_mutex);

 *** DEADLOCK ***

This bug is due to the f2fs_balance_fs call in f2fs_write_data_page.
If f2fs_write_data_page is triggered by wbc->for_reclaim via kswapd, it should
not call f2fs_balance_fs which tries to get a mutex grabbed by original syscall
flow.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: missing REQ_META and REQ_PRIO when sync_meta_pages(META_FLUSH)

Doing sync_meta_pages with META_FLUSH when checkpoint, we overide rw
using WRITE_FLUSH_FUA. At this time, we also should set
REQ_META|REQ_PRIO.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: clean checkpatch warnings

Fixed a variety of trivial checkpatch warnings.  The only delta should
be some minor formatting on log strings that were split / too long.

Signed-off-by: Chris Fries <cfries@motorola.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: call mark_inode_dirty to flush dirty pages

If a dentry page is updated, we should call mark_inode_dirty to add the inode
into the dirty list, so that its dentry pages are flushed to the disk.
Otherwise, the inode can be evicted without flush.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: move a branch for code redability

This patch moves a function in f2fs_delete_entry for code readability.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add help function META_MAPPING

Introduce help function META_MAPPING() to get the cache meta blocks'
address space.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove the orphan block page array

As the orphan_blocks may be max to 504, so it is not security
and rigorous to store such a large array in the kernel stack
as Dan Carpenter said.
In fact, grab_meta_page has locked the page in the page cache,
and we can use find_get_page() to fetch the page safely in the
downstream, so we can remove the page array directly.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce NODE_MAPPING for code consistency

This patch adds NODE_MAPPING which is similar as META_MAPPING introduced by
Gu Zheng.

Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: drop obsolete node page when it is truncated

If a node page is trucated, we'd better drop the page in the node_inode's page
cache for better memory footprint.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Conflicts:
	Documentation/filesystems/f2fs.txt
	fs/f2fs/Makefile
	fs/f2fs/checkpoint.c
	fs/f2fs/data.c
	fs/f2fs/debug.c
	fs/f2fs/dir.c
	fs/f2fs/f2fs.h
	fs/f2fs/node.c
	fs/f2fs/node.h
	fs/f2fs/recovery.c
	fs/f2fs/segment.c
	fs/f2fs/segment.h
	fs/f2fs/xattr.c
	include/linux/f2fs_fs.h
	include/trace/events/f2fs.h

f2fs: handle dirty segments inside refresh_sit_entry

This patch cleans up the refresh_sit_entry to handle locate_dirty_segments.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix to recover xattr node block

If a new xattr node page was allocated and its inode is fsynced, we should
recover the xattr node page during the roll-forward process after power-cut.
But, previously, f2fs didn't handle that case, resulting in kernel panic as
follows reported by Tom Li.

BUG: unable to handle kernel paging request at ffffc9001c861a98
IP: [<ffffffffa0295236>] check_index_in_prev_nodes+0x86/0x2d0 [f2fs]
Call Trace:
 [<ffffffff815ece9b>] ? printk+0x48/0x4a
 [<ffffffffa029626a>] recover_fsync_data+0xdca/0xf50 [f2fs]
 [<ffffffffa02873ae>] f2fs_fill_super+0x92e/0x970 [f2fs]
 [<ffffffff8112c9f8>] mount_bdev+0x1b8/0x200
 [<ffffffffa0286a80>] ? f2fs_remount+0x130/0x130 [f2fs]
 [<ffffffffa0285e40>] f2fs_mount+0x10/0x20 [f2fs]
 [<ffffffff8112d4de>] mount_fs+0x3e/0x1b0
 [<ffffffff810ef4eb>] ? __alloc_percpu+0xb/0x10
 [<ffffffff8114761f>] vfs_kern_mount+0x6f/0x120
 [<ffffffff811497b9>] do_mount+0x259/0xa90
 [<ffffffff810ead1d>] ? memdup_user+0x3d/0x80
 [<ffffffff810eadb3>] ? strndup_user+0x53/0x70
 [<ffffffff8114a2c9>] SyS_mount+0x89/0xd0
 [<ffffffff815feae2>] system_call_fastpath+0x16/0x1b

This patch adds a recovery function of xattr node pages.

Reported-by: Tom Li <biergaizi@members.fsf.org>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove the ugly pointer conversion

This patch modifies the use of bi_private to remove pointer chasing for sbi.
Previously, we had a bi_private structure, but it needs memory allocation.
So this patch uses bi_private by the sbi pointer and adds a completion pointer
into the sbi.
This can achieve no memory allocation and nice use of the bi_private.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix the potential mismatch between dir's i_size and i_blocks

This is the erroneous scenario.

                             i_size    on-disk i_size    i_blocks
__f2fs_add_link()             4096           4096           2
 get_new_data_page            8192           4096           3
 -ENOSPC = init_inode_metadata
 checkpoint                     -            4096           3
 POR and reboot

__f2fs_add_link()             4096           4096           3
 page = get_new_data_page (page->index = 1 by NEW_ADDR)
 add a dentry to the page successfully

f2fs_rmdir()
 f2fs_empty_dir()             4096           4096           3
 f2fs_unlink() goes, since there is no valid dentry due to i_size = 4096.
 But, still there is one dentry in page->index = 1.

So this patch moves the code to write dir->i_size into on-disk i_size in order
to sync dir's i_size, on-disk i_size, and its i_blocks.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: clean up with a macro

This patch adds GET_BLKOFF_FROM_SEG0 to clean up some codes.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix a build warning

This patch modifies flow a little bit to avoid the following build warnings.

src/fs/f2fs/recovery.c: In function ‘check_index_in_prev_nodes’:
src/fs/f2fs/recovery.c:288:51: warning: ‘sum.<U5390>.<U52f8>.ofs_in_node’ may
	be used uninitialized in this function [-Wmaybe-uninitialized]
src/fs/f2fs/recovery.c:260:23: warning: ‘sum.nid’ may be used uninitialized
	in this function [-Wmaybe-uninitialized]

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix to truncate dentry pages in the error case

When a new directory is allocated, if an error is occurred, we should truncate
preallocated dentry pages too.

This bug was reported by Andrey Tsyvarev after a while as follows.

mkdir()->
 f2fs_add_link()->
  init_inode_metadata()->
    f2fs_init_acl()->
      f2fs_get_acl()->
        f2fs_getxattr()->
          read_all_xattrs() fails.

Also there was a BUG_ON triggered after the fault in
mkdir()->
 f2fs_add_link()->
   init_inode_metadata()->
    remove_inode_page() ->
      f2fs_bug_on(inode->i_blocks != 0 && inode->i_blocks != 1);

But, previous patch wasn't perfect to resolve that bug, so the following bug
report was also submitted.

kernel BUG at fs/f2fs/inode.c:274!
Call Trace:
 [<ffffffff811fde03>] evict+0xa3/0x1a0
 [<ffffffff811fe615>] iput+0xf5/0x180
 [<ffffffffa01c7f63>] f2fs_mkdir+0xf3/0x150 [f2fs]
 [<ffffffff811f2a77>] vfs_mkdir+0xb7/0x160
 [<ffffffff811f36bf>] SyS_mkdir+0x5f/0xc0
 [<ffffffff81680769>] system_call_fastpath+0x16/0x1b

Finally, this patch resolves all the issues like below.

If an error is occurred after make_empty_dir(),
 1. truncate_inode_pages()
   The make_bad_inode() prior to iput() will change i_mode to S_IFREG, which
   means that f2fs will not decrement fi->dirty_dents during f2fs_evict_inode.
   But, by calling it here, we can do that.

 2. truncate_blocks()
   Preallocated dentry pages are trucated here to sync i_blocks.

 3. remove_dirty_dir_inode()
   Remove this directory inode from the list.

Reported-and-Tested-by: Andrey Tsyvarev <tsyvarev@ispras.ru>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix f2fs_write_meta_page at no checkpoint status

If f2fs entered errorneous checkpoint status, it should skip writing meta
pages instead of redirtying the pages out.
Otherwise, it cannot unmount the partition even though f2fs is under read-only
status.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: clean up redundant function call

This patch integrates inode_[inc|dec]_dirty_dents with inc_page_count to remove
redundant calls.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: use inode mutex to keep atomicity of f2fs_falloc

Previously without protection of inode mutex, f2fs_falloc and other data
correlated operations will interfere with each other.
So let's use inode mutex to keep atomicity of f2fs_falloc.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce ra_meta_pages to readahead CP/NAT/SIT pages

This patch help us to cleanup the readahead code by merging ra_{sit,nat}_pages
function into ra_meta_pages.
Additionally the new function is used to readahead cp block in
recover_orphan_inodes.

Change log from v1:
 o fix a deadloop bug pointed by Jaegeuk Kim.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: show counts of checkpoint in status

This patch shows the counts of checkpoint in f2fs' status.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix the calculation of max_nids

Total nids that f2fs can use should not include 0, nid for node inode, and nid
for meta inode.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix not to write data pages on the page reclaiming path

Even if f2fs_write_data_page is called by the page reclaiming path, we should
not write the page to provide enough free segments for the worst case scenario.
Otherwise, f2fs can face with no free segment while gc is conducted, resulting
in:

 ------------[ cut here ]------------
 kernel BUG at /home/zeus/f2fs_test/src/fs/f2fs/segment.c:565!
 RIP: 0010:[<ffffffffa02c3b11>]  [<ffffffffa02c3b11>] new_curseg+0x331/0x340 [f2fs]
 Call Trace:
  allocate_segment_by_default+0x204/0x280 [f2fs]
  allocate_data_block+0x108/0x210 [f2fs]
  write_data_page+0x8a/0xc0 [f2fs]
  do_write_data_page+0xe1/0x2a0 [f2fs]
  move_data_page+0x8a/0xf0 [f2fs]
  f2fs_gc+0x446/0x970 [f2fs]
  f2fs_balance_fs+0xb6/0xd0 [f2fs]
  f2fs_write_begin+0x50/0x350 [f2fs]
  ? unlock_page+0x27/0x30
  ? unlock_page+0x27/0x30
  generic_file_buffered_write+0x10a/0x280
  ? file_update_time+0xa3/0xf0
  __generic_file_aio_write+0x1c8/0x3d0
  ? generic_file_aio_write+0x52/0xb0
  ? generic_file_aio_write+0x52/0xb0
  generic_file_aio_write+0x65/0xb0
  do_sync_write+0x5a/0x90
  vfs_write+0xc5/0x1f0
  SyS_write+0x55/0xa0
  system_call_fastpath+0x16/0x1b

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix to do build_stat prior to the recovery procedure

At the end of the recovery procedure, write_checkpoint is called and updates
the cp count which is managed by f2fs stat.
But, previously build_stat() is called after the recovery procedure, which
results in:

BUG: unable to handle kernel NULL pointer dereference at 000000000000012c
IP: [<ffffffffa03b1030>] write_checkpoint+0x720/0xbc0 [f2fs]
Call Trace:
 [<ffffffff810a6b44>] ? mark_held_locks+0x74/0x140
 [<ffffffff8109a3e0>] ? __init_waitqueue_head+0x60/0x60
 [<ffffffffa03bf036>] recover_fsync_data+0x656/0xf20 [f2fs]
 [<ffffffff812ee3eb>] ? security_d_instantiate+0x1b/0x30
 [<ffffffffa03aeb4d>] f2fs_fill_super+0x94d/0xa00 [f2fs]
 [<ffffffff811a9825>] mount_bdev+0x1a5/0x1f0
 [<ffffffff8114915e>] ? __get_free_pages+0xe/0x40
 [<ffffffffa03ae200>] ? f2fs_remount+0x130/0x130 [f2fs]
 [<ffffffffa03aa575>] f2fs_mount+0x15/0x20 [f2fs]
 [<ffffffff811aa713>] mount_fs+0x43/0x1b0
 [<ffffffff811c7124>] vfs_kern_mount+0x74/0x160
 [<ffffffff811c5cb1>] ? __get_fs_type+0x51/0x60
 [<ffffffff811c9727>] do_mount+0x237/0xb50
 [<ffffffff811c936a>] ? copy_mount_options+0x3a/0x170

So, this patche changes the order of recovery_fsync_data() and
f2fs_build_stats().

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix to mark the checkpointed nat entry correctly

The nat cache entry maintains a status whether it is checkpointed or not.
So, if a new cache entry is loaded from the last checkpoint,
nat_entry->checkpointed should be true.
If the cache entry is modified as being dirty, nat_entry->checkpoint should
be false.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce help macro on_build_free_nids()

Introduce help macro on_build_free_nids() which just uses build_lock
to judge whether the building free nid is going, so that we can remove
the on_build_free_nids field from f2fs_sb_info.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
[Jaegeuk Kim: remove an unnecessary white line removal]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce a radix_tree for the free_nid list

This patch introduces a radix tree for the list of free_nids, which enhances
the performance on free nid management.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: implement a lock-free stat_show

The stat_show is just to show the current status of f2fs.
So, we can remove all the there-in locks.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove costly bit operations for f2fs_find_entry

It turns out that a bit operation like find_next_bit is not always fast enough
for f2fs_find_entry.
Instead, it is pretty much simple and fast to traverse each dentries.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce large directory support

This patch introduces an i_dir_level field to support large directory.

Previously, f2fs maintains multi-level hash tables to find a dentry quickly
from a bunch of chiild dentries in a directory, and the hash tables consist of
the following tree structure as below.

In Documentation/filesystems/f2fs.txt,

----------------------
A : bucket
B : block
N : MAX_DIR_HASH_DEPTH
----------------------

level #0   | A(2B)
           |
level #1   | A(2B) - A(2B)
           |
level #2   | A(2B) - A(2B) - A(2B) - A(2B)
     .     |   .       .       .       .
level #N/2 | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
     .     |   .       .       .       .
level #N   | A(4B) - A(4B) - A(4B) - A(4B) - A(4B) - ... - A(4B)

But, if we can guess that a directory will handle a number of child files,
we don't need to traverse the tree from level #0 to #N all the time.
Since the lower level tables contain relatively small number of dentries,
the miss ratio of the target dentry is likely to be high.

In order to avoid that, we can configure the hash tables sparsely from level #0
like this.

level #0   | A(2B) - A(2B) - A(2B) - A(2B)

level #1   | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
     .     |   .       .       .       .
level #N/2 | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
     .     |   .       .       .       .
level #N   | A(4B) - A(4B) - A(4B) - A(4B) - A(4B) - ... - A(4B)

With this structure, we can skip the ineffective tree searches in lower level
hash tables.

This patch adds just a facility for this by introducing i_dir_level in
f2fs_inode.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: update documents and a MAINTAINERS entry

This patch adds missing some description of sysfs entries in
 - Documentation/ABI/testing/sysfs-fs-f2fs
 - Documentation/filesystems/f2fs.txt.

And it adds a maintained document entry of F2FS in MAINTAINERS.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Conflicts:
	Documentation/ABI/testing/sysfs-fs-f2fs
	MAINTAINERS

f2fs: add an sysfs entry to control the directory level

This patch adds an sysfs entry to control dir_level used by the large directory.

The description of this entry is:

 dir_level                    This parameter controls the directory level to
			      support large directory. If a directory has a
			      number of files, it can reduce the file lookup
			      latency by increasing this dir_level value.
			      Otherwise, it needs to decrease this value to
			      reduce the space overhead. The default value is 0.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: readahead contiguous SSA blocks for f2fs_gc

If there are multi segments in one section, we will read those SSA blocks which
have contiguous address one by one in f2fs_gc. It may lost performance, let's
read ahead SSA blocks by merge multi read request.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: use existing macro to clean up some codes

This patch use existing macro F2FS_INODE/NEXT_FREE_BLKADDR to clean up some
codes.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix dirty page accounting when redirty

We should de-account dirty counters for page when redirty in ->writepage().

Wu Fengguang described in 'commit 971767caf632190f77a40b4011c19948232eed75':
"writeback: fix dirtied pages accounting on redirty
De-account the accumulative dirty counters on page redirty.

Page redirties (very common in ext4) will introduce mismatch between
counters (a) and (b)

a) NR_DIRTIED, BDI_DIRTIED, tsk->nr_dirtied
b) NR_WRITTEN, BDI_WRITTEN

This will introduce systematic errors in balanced_rate and result in
dirty page position errors (ie. the dirty pages are no longer balanced
around the global/bdi setpoints)."

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix to write node pages with WRITE_SYNC

This patch fixes performance regression of dbench reported by
Alex <hbx7d@yandex.com>.

This issue was revealed by Phoronix tests results:
http://www.phoronix.com/scan.php?page=article&item=linux_314_ssdfs&num=2

It turns out that we need to assign WRITE_SYNC to the node writes, if
fsync is triggered.

The performance numbers are like below, which is measured by Alex.
1. 355MB/s       ext4
2. 225MB/s       f2fs : WRITE for node writes
3. 525MB/s       f2fs : WRITE_SYNC for node writes

Reported-And-Tested-by: Alex <hbx7d@yandex.com>.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix wrong kernel coding style

This patch includes a simple fix to adjust coding style.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: update start nid only once each circle

Integrated a couple of minor changes for better readability suggested by
Chao Yu.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove the unused ctor argument of f2fs_kmem_cache_create()

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: format segment_info's show for better legibility

The original segment_info's show is a bit out-of-format:

[root@guz Demoes]# cat /proc/fs/f2fs/loop0/segment_info
0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
......
0 0 0 0 0 0 0 0 0 0
0 0 1 0 0 1 [root@guz Demoes]#

so we fix it here for better legibility.
[root@guz Demoes]# cat /proc/fs/f2fs/loop0/segment_info
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
......
0 0 0 0 0 0 0 0 0 0
0 0 1 0 0 1
[root@guz Demoes]#

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: optimize restore_node_summary slightly

Previously, we ra_sum_pages to pre-read contiguous pages as more
as possible, and if we fail to alloc more pages, an ENOMEM error
will be reported upstream, even though we have alloced some pages
yet. In fact, we can use the available pages to do the job partly,
and continue the rest in the following circle. Only reporting ENOMEM
upstream if we really can not alloc any available page.

And another fix is ignoring dealing with the following pages if an
EIO occurs when reading page from page_list.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: modify the flow for better neat code]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: recover inline xattr data in roll-forward process

Previously we do not recover inline xattr data of inode after power-cut, so
inline xattr data may be lost.
We should recover the data during the roll-forward process.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce f2fs_has_inline_xattr for better readability

This patch introduces a help function f2fs_has_inline_xattr for better
readability.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: check upper bound of ino value in f2fs_nfs_get_inode

Upper bound checking of ino should be added to f2fs_nfs_get_inode, so unneeded
process before do_read_inode in f2fs_iget could be avoided when ino is invalid.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: print type for each segment in segment_info's show

The original segment_info's show looks out-of-format:
cat /proc/fs/f2fs/loop0/segment_info
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 512
512 512 512 512 512 512 512 0 0 512
348 0 263 0 0 512 0 0 512 512
512 512 0 512 512 512 512 512 512 512
512 512 511 328 512 512 512 512 512 512
512 512 512 512 512 512 512 0 0 175

Let's fix this and show type for each segment.
cat /proc/fs/f2fs/loop0/segment_info
format: segment_type|valid_blocks
segment_type(0:HD, 1:WD, 2:CD, 3:HN, 4:WN, 5:CN)
0    2|0   1|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0
10   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0
20   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0
30   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0
40   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0   0|0
50   3|0   3|0   3|0   3|0   3|0   3|0   3|0   0|0   3|0   3|0
60   3|0   3|0   3|0   3|0   3|0   3|0   3|0   3|0   3|0   3|512
70   3|512 3|512 3|512 3|512 3|512 3|512 3|512 3|0   3|0   3|512
80   3|0   3|0   3|0   3|0   3|0   3|512 3|0   3|0   3|512 3|512
90   3|512 0|512 3|274 0|512 0|512 0|512 0|512 0|512 0|512 3|512
100  3|512 0|512 3|511 0|328 3|512 0|512 0|512 3|512 0|512 0|512
110  0|512 0|512 0|512 0|512 0|512 0|512 0|512 5|0   4|0   3|512

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce f2fs_has_xattr_block for better readability

This patch introduces a help function f2fs_has_xattr_block for better
readability.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid to return incorrect errno of read_normal_summaries

We should return error number of read_normal_summaries instead of -EINVAL when
read_normal_summaries failed.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix incorrect parsing with option string

Previously 'background_gc={on***,off***}' is being parsed as correct option,
with this patch we cloud fix the trivial bug in mount process.

Change log from v1:
 o need to check length of parameter suggested by Jaegeuk Kim.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce get_dirty_dents for readability

The get_dirty_dents gives us the number of dirty dentry pages.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid small data writes by skipping writepages

This patch introduces nr_pages_to_skip(sbi, type) to determine writepages can
be skipped.
The dentry, node, and meta pages can be conrolled by F2FS without breaking the
FS consistency.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: increase pages_skipped when skipping writepages

This patch increases pages_skipped when skipping writepages.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce nr_pages_to_write for segment alignment

This patch introduces nr_pages_to_write to align page writes to the segment
or other operational unit size, which can be tuned according to the system
environment.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: call f2fs_wait_on_page_writeback instead of native function

If a page is on writeback, f2fs can face with deadlock due to under writepages.
This is caused by merging IOs inside f2fs, so if it comes to detect, let's throw
merged IOs, which is implemented by f2fs_wait_on_page_writeback.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid to drop nat entries due to the negative nr_shrink

The try_to_free_nats should not receive the negative nr_shrink.
Otherwise, it can drop all the nat entries by the while loop.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: throttle the memory footprint with a sysfs entry

This patch introduces ram_thresh, a sysfs entry, which controls the memory
footprint used by the free nid list and the nat cache.

Previously, the free nid list was controlled by MAX_FREE_NIDS, while the nat
cache was managed by NM_WOUT_THRESHOLD.
However, this approach cannot be applied dynamically according to the system.

So, this patch adds ram_thresh that users can specify the threshold, which is
in order of 1 / 1024.
For example, if the total ram size is 4GB and the value is set to 10 by default,
f2fs tries to control the number of free nids and nat caches not to consume over
10 * (4GB / 1024) = 10MB.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove unnecessary threshold

The NM_WOUT_THRESHOLD is now obsolete since f2fs starts to control on a basis
of the memory footprint.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: change reclaim rate in percentage

It is more reasonable to determine the reclaiming rate of prefree segments
according to the volume size, which is set to 5% by default.
For example, if the volume is 128GB, the prefree segments are reclaimed
when the number reaches to 6.4GB.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce fi->i_sem to protect fi's info

This patch introduces fi->i_sem to protect fi's info that includes xattr_ver,
pino, i_nlink.
This enables to remove i_mutex during f2fs_sync_file, resulting in performance
improvement when a number of fsync calls are triggered from many concurrent
threads.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: skip unnecessary node writes during fsync

If multiple redundant fsync calls are triggered, we don't need to write its
node pages with fsync mark continuously.

So, this patch adds FI_NEED_FSYNC to track whether the latest node block is
written with the fsync mark or not.
If the mark was set, a new fsync doesn't need to write a node block.
Otherwise, we should do a new node block with the mark for roll-forward
recovery.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid RECLAIM_FS-ON-W warning

This patch should resolve the following possible bug.

RECLAIM_FS-ON-W at:
 mark_held_locks+0xb9/0x140
 lockdep_trace_alloc+0x85/0xf0
 __kmalloc+0x53/0x1d0
 read_all_xattrs+0x3d1/0x3f0 [f2fs]
 f2fs_getxattr+0x4f/0x100 [f2fs]
 f2fs_get_acl+0x4c/0x290 [f2fs]
 get_acl+0x4f/0x80
 posix_acl_create+0x72/0x180
 f2fs_init_acl+0x29/0xcc [f2fs]
 __f2fs_add_link+0x259/0x710 [f2fs]
 f2fs_create+0xad/0x1c0 [f2fs]
 vfs_create+0xed/0x150
 do_last+0xd36/0xed0
 path_openat+0xc5/0x680
 do_filp_open+0x43/0xa0
 do_sys_open+0x13c/0x230
 SyS_creat+0x1e/0x20
 system_call_fastpath+0x16/0x1b

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: return -EIO when node id is not matched

During the cleaing of node segments, F2FS can get errored node blocks due to
data race between node page lock and its valid bitmap operations.
In that case, it needs to return an error to skip such the obsolete block copy.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid unneeded lookup when xattr name length is too long

In f2fs_setxattr we have limit this attribute name length, so we should also
check it in f2fs_getxattr to avoid useless lookup caused by invalid name length.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid free slab cache under spinlock

Move kmem_cache_free out of spinlock protection region for better performance.

Change log from v1:
 o remove spinlock protection for kmem_cache_free in destroy_node_manager
suggested by Jaegeuk Kim.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: use list_for_each_entry{_safe} for simplyfying code

This patch use list_for_each_entry{_safe} instead of list_for_each{_safe} for
simplfying code.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix error path when fail to read inline data

We should unlock page in ->readpage() path and also should unlock & release page
in error path of ->write_begin() to avoid deadlock or memory leak.
So let's add release code to fix the problem when we fail to read inline data.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: update f2fs Documentation

This patch describes the inline_data support in f2fs document.

Signed-off-by: Huajun Li <huajun.li@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix wrong statistics of inline data

If we remove a file that has inline data after mount, our statistics turns to
inaccurate.

cat /sys/kernel/debug/f2fs/status
  - Inline_data Inode: 4294967295

Let's add stat_inc_inline_inode() to stat inline info of the file when lookup.

Change log from v1:
 o stat in f2fs_lookup() instead of in do_read_inode() for excluding wrong stat.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid to conduct roll-forward due to the remained garbage blocks

The f2fs always scans the next chain of direct node blocks.
But some garbage blocks are able to be remained due to no discard support or
SSR triggers.
This occasionally wreaks recovering wrong inodes that were used or BUG_ONs
due to reallocating node ids as follows.

When mount this f2fs image:
http://linuxtesting.org/downloads/f2fs_fault_image.zip
BUG_ON is triggered in f2fs driver (messages below are generated on
kernel 3.13.2; for other kernels output is similar):

kernel BUG at fs/f2fs/node.c:215!
 Call Trace:
 [<ffffffffa032ebad>] recover_inode_page+0x1fd/0x3e0 [f2fs]
 [<ffffffff811446e7>] ? __lock_page+0x67/0x70
 [<ffffffff81089990>] ? autoremove_wake_function+0x50/0x50
 [<ffffffffa0337788>] recover_fsync_data+0x1398/0x15d0 [f2fs]
 [<ffffffff812b9e5c>] ? selinux_d_instantiate+0x1c/0x20
 [<ffffffff811cb20b>] ? d_instantiate+0x5b/0x80
 [<ffffffffa0321044>] f2fs_fill_super+0xb04/0xbf0 [f2fs]
 [<ffffffff811b861e>] ? mount_bdev+0x7e/0x210
 [<ffffffff811b8769>] mount_bdev+0x1c9/0x210
 [<ffffffffa0320540>] ? validate_superblock+0x210/0x210 [f2fs]
 [<ffffffffa031cf8d>] f2fs_mount+0x1d/0x30 [f2fs]
 [<ffffffff811b9497>] mount_fs+0x47/0x1c0
 [<ffffffff81166e00>] ? __alloc_percpu+0x10/0x20
 [<ffffffff811d4032>] vfs_kern_mount+0x72/0x110
 [<ffffffff811d6763>] do_mount+0x493/0x910
 [<ffffffff811615cb>] ? strndup_user+0x5b/0x80
 [<ffffffff811d6c70>] SyS_mount+0x90/0xe0
 [<ffffffff8166f8d9>] system_call_fastpath+0x16/0x1b

Found by Linux File System Verification project (linuxtesting.org).

Reported-by: Andrey Tsyvarev <tsyvarev@ispras.ru>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: call redirty_page_for_writepage

This patch replace some general codes with redirty_page_for_writepage, which
can be enabled after consideration on additional procedure like counting dirty
pages appropriately.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix to unlock f2fs_lock at the omitted error case

If it occurs an error, we should call f2fs_unlock_op.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove costly dirty_dir_inode operations

This patch removes list opeations in handling dirty dir inodes.
Previously, F2FS traverses whole the list of dirty dir inodes to check whether
there is an existing inode or not, resulting in heavy CPU overheads.

So this patch removes such the traverse operations by adding FI_DIRTY_DIR to
indicate the inode lies on the list or not.
Through this simple flag, we can remove redundant operations gracefully.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: make recover_inline_xattr() static

Make recover_inline_xattr() static, because this function is
used only in this file.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: atomically set inode->i_flags in f2fs_set_inode_flags()

Use set_mask_bits() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
FS_IMMUTABLE_FL, FS_APPEND_FL, etc. flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time.

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add static to get_max_meta_blks

inline get_max_meta_blks is only used in checkpoint.c
Use standard static inline format.

Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add available_nids to fix handling max_nid correctly

This patch introduces available_nids for alloc_nids() and fixes max_nid for
build_free_nids() and scan_nat_pages().

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid BUG_ON when mouting corrupted image having garbage blocks

If the disk has some garbage blocks, F2FS is able to face with BUG_ON when
recovering direct node blocks.
This patch detects the error case and avoids that prior to reaching BUG_ON.

Alexey Khoroshilov addressed the potential security issues as follows.
"An ability to trigger a BUG_ON assert by mounting a crafted image is
usually considered as a local denial of service [1-3]. As far as I
understand, the reason is that some kernel data may become inconsistent
that can lead to further problems.

[1] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-3353
[2] http://www.openwall.com/lists/oss-security/2011/06/24/4
[3] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-2928
etc."

Reported-by: Andrey Tsyvarev <tsyvarev@ispras.ru>
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce raw_nat_from_node_info() to simplfy codes

This patch introduce raw_nat_from_node_info() to simplfy some codes, and also
use exist function node_info_from_raw_nat() to do the same job.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: adjust free mem size to flush dentry blocks

If so many dirty dentry blocks are cached, not reached to the flush condition,
we should fall into livelock in balance_dirty_pages.
So, let's consider the mem size for the condition.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: handle inline data independently in f2fs_bmap

We'd better handle inline data case independently in f2fs_bmap().
It can reduce our handling time in f2fs_bmap().

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: clean up long variable names

This patch includes simple clean-ups to reduce unnecessary long variable names.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Conflicts:
	fs/f2fs/xattr.h

f2fs: pass flags field to setxattr functions

This patch passes the "flags" field to the low level setxattr functions
to use XATTR_REPLACE in the following patches.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: return errors right after checking them

This patch adds two error conditions early in the setxattr operations.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: submit bio at the reclaim path

If f2fs_write_data_page is called through the reclaim path, we should submit
the bio right away.

This patch resolves the following issue that Marc Dietrich reported.
"It took me a while to bisect a problem which causes my ARM (tegra2) netbook to
frequently stall for 5-10 seconds when I enable EXA acceleration (opentegra
experimental ddx)."
And this patch fixes that.

Reported-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce help macro ADDRS_PER_PAGE()

Introduce help macro ADDRS_PER_PAGE() to get the number of address pointers in
direct node or inode.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: set errno when f2fs_iget failed in recover_dentry

We should set the error number correctly when we fail in recover_dentry(), so
the recover flow could stop for the reason as error number shows instead of
continuing.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: readahead multi pages of directory for performance

We have no so such readahead mechanism in ->iterate() path as the one in
->read() path, it cause low performance when we read large directory.
This patch add readahead in f2fs_readdir() for better performance.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Conflicts:
	fs/f2fs/dir.c

f2fs: fix to truncate inline data in inode page when setattr

Previous we do not truncate inline data in inode page when setattr, so following
case could still read the inline data which has already truncated:

1.write inline data
2.ftruncate size to 0
3.ftruncate size to max inline data size
4.read from offset 0

This patch introduces truncate_inline_data() to fix this problem.

change log from v1:
 o fix a bug and do not truncate first page data after truncate inline data.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: split grab_cache_page and wait_on_page_writeback for node pages

This patch splits grab_cache_page_write_begin into grab_cache_page and
wait_on_page_writeback for node pages.

This patch intends to enhance the latency to get node pages by alleviating
unnecessary wait_on_page_writeback.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid grab_cache_page_write_begin for data pages

We don't need to wait on page writeback for these cases.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: no need to wait on page writebck to meta pages

This patch removes grab_cache_page_write_begin for meta pages.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: decrease the lock granularity during write_begin

This patch reduces the lock granularity during write_begin.
When the system is under memory pressure, it would be better to reduce
the locking time for the data pages.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix checkpatch warning

fix the following checkpatch warning:
WARNING: do {} while (0) macros should not be semicolon terminated

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a tracepoint for f2fs_write_begin

This patch adds a tracepoint for f2fs_write_begin to trace write op of user.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a tracepoint for f2fs_write_end

This patch adds a tracepoint for f2fs_write_end to trace write op of user.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a tracepoint for f2fs_write_{meta,node,data}_page

This patch adds a tracepoint for f2fs_write_{meta,node,data}_page to trace when
page is writting out.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a tracepoint for f2fs_write_{meta,node,data}_pages

This patch adds a tracepoint for f2fs_write_{meta,node,data}_pages to trace when
pages are fsyncing/flushing.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add a tracepoint for f2fs_read_data_page

This patch adds a tracepoint for f2fs_read_data_page to trace when page is
readed by user.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix recursive lock by f2fs_setxattr

This patch should resolve the following recursive lock.

[<ffffffff8135a9c3>] call_rwsem_down_write_failed+0x13/0x20
[<ffffffffa01749dc>] f2fs_setxattr+0x5c/0xa0 [f2fs]
[<ffffffffa0174c99>] __f2fs_set_acl+0x1b9/0x340 [f2fs]
[<ffffffffa017515a>] f2fs_init_acl+0x4a/0xcb [f2fs]
[<ffffffffa0159abe>] __f2fs_add_link+0x26e/0x780 [f2fs]
[<ffffffffa015d4d8>] f2fs_mkdir+0xb8/0x150 [f2fs]
[<ffffffff811cebd7>] vfs_mkdir+0xb7/0x160
[<ffffffff811cf89b>] SyS_mkdir+0xab/0xe0
[<ffffffff817244bf>] tracesys+0xe1/0xe6
[<ffffffffffffffff>] 0xffffffffffffffff

The call path indicates:
- f2fs_add_link
   : down_write(&fi->i_sem);

 - init_inode_metadata
   - f2fs_init_acl
     - __f2fs_set_acl
       - f2fs_setxattr
         : down_write(&fi->i_sem);

Here we should not call f2fs_setxattr, but __f2fs_setxattr.
But __f2fs_setxattr is a static function in xattr.c, so that I found the other
generic approach to use f2fs_setxattr.

In f2fs_setxattr, the page pointer is only given from init_inode_metadata.
So, this patch adds this condition to avoid this in f2fs_setxattr.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid overflow when large directory feathure is enabled

When large directory feathure is enable, We have one case which could cause
overflow in dir_buckets() as following:
special case: level + dir_level >= 32 and level < MAX_DIR_HASH_DEPTH / 2.

Here we define MAX_DIR_BUCKETS to limit the return value when the condition
could trigger potential overflow.

Changes from V1
 o modify description of calculation in f2fs.txt suggested by Changman Lee.

Suggested-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid crash when trace f2fs_submit_page_mbio event in ra_sum_pages

Previously we allocate pages with no mapping in ra_sum_pages(), so we may
encounter a crash in event trace of f2fs_submit_page_mbio where we access
mapping data of the page.

We'd better allocate pages in bd_inode mapping and invalidate these pages after
we restore data from pages. It could avoid crash in above scenario.

Changes from V1
 o remove redundant code in ra_sum_pages() suggested by Jaegeuk Kim.

Call Trace:
 [<f1031630>] ? ftrace_raw_event_f2fs_write_checkpoint+0x80/0x80 [f2fs]
 [<f10377bb>] f2fs_submit_page_mbio+0x1cb/0x200 [f2fs]
 [<f103c5da>] restore_node_summary+0x13a/0x280 [f2fs]
 [<f103e22d>] build_curseg+0x2bd/0x620 [f2fs]
 [<f104043b>] build_segment_manager+0x1cb/0x920 [f2fs]
 [<f1032c85>] f2fs_fill_super+0x535/0x8e0 [f2fs]
 [<c115b66a>] mount_bdev+0x16a/0x1a0
 [<f102f63f>] f2fs_mount+0x1f/0x30 [f2fs]
 [<c115c096>] mount_fs+0x36/0x170
 [<c1173635>] vfs_kern_mount+0x55/0xe0
 [<c1175388>] do_mount+0x1e8/0x900
 [<c1175d72>] SyS_mount+0x82/0xc0
 [<c16059cc>] sysenter_do_call+0x12/0x22

Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: large volume support

f2fs's cp has one page which consists of struct f2fs_checkpoint and
version bitmap of sit and nat. To support lots of segments, we need more
blocks for sit bitmap. So let's arrange sit bitmap as following:
+-----------------+------------+
| f2fs_checkpoint | sit bitmap |
| + nat bitmap    |            |
+-----------------+------------+
0                 4k        N blocks

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
[Jaegeuk Kim: simple code change for readability]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to recover data written by dio

If data are overwritten through dio, previous f2fs doesn't remain the fsync mark
due to no additional node writes.

Note that this patch should resolve the xfstests:311.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: recover fallocated space

If a fallocated file is fsynced, we should recover the i_size after sudden
power cut.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid not to call remove_dirty_inode

There is an errorneous case during the recovery like below.

In recovery_dentry,
 1) dir = f2fs_iget();
 2) mark the dir with FI_DELAY_IPUT
 3) goto unmap_out

After the end of recovery routine, there is no dirty dentries so the dir cannot
be released by iput in remove_dirty_dir_inode.

This patch fixes such the bug case by handling the iget and iput in the
recovery_dentry procedure.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support f2fs_fiemap

This patch links f2fs_fiemap with generic function with get_block.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to report newly allocate region as extent

Previous get_block in f2fs didn't report the newly allocated region which has
NEW_ADDR.
For reader, it should not report, but fiemap needs this.
So, this patch introduces two get_block sharing core function.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: recover fallocated data and its i_size together

This patch arranges the f2fs_locks to cover the fallocated data and its i_size.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix not to allocate unnecessary blocks during fallocate

This patch fixes the fallocate bug like below. (See xfstests/255)

In fallocate(fd, 0, 20480),
expand_inode_data processes
	for (index = pg_start; index <= pg_end; index++) {
		f2fs_reserve_block();
		...
	}

So, even though fallocate requests 20480, 5 blocks, f2fs allocates 6 blocks
including pg_end.
So, this patch adds one condition to avoid block allocation.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unused variables in f2fs_sm_info

Remove unused variables in struct f2fs_sm_info.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check lower bound nid value in check_nid_range

This patch add lower bound verification for nid in check_nid_range, so nids
reserved like 0, node, meta passed by caller could be checked there.

And then check_nid_range could be used in f2fs_nfs_get_inode for simplifying
code.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix error path in init_inode_metadata

If we fail in this path:
->init_inode_metadata
  ->make_empty_dir
    ->get_new_data_page
      ->grab_cache_page return -ENOMEM

We will bug on in error path of init_inode_metadata when call remove_inode_page
because i_block = 2 (one inode block will be released later & one dentry block).

We should release the dentry block in init_inode_metadata to avoid this BUG_ON,
and avoid leak of dentry block resource, because we never have second chance to
release that block in ->evict_inode as in upper error path we make this inode
'bad'.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: release new entry page correctly in error path of f2fs_rename

This patch correct releasing code of new_page to avoid BUG_ON in error patch of
f2fs_rename.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do checkpoint for the renamed inode

If an inode is renamed, it should be registered as file_lost_pino to conduct
checkpoint at f2fs_sync_file.
Otherwise, the inode cannot be recovered due to no dent_mark in the following
scenario.

Note that, this scenario is from xfstests/322.

1. create "a"
2. fsync "a"
3. rename "a" to "b"
4. fsync "b"
5. Sudden power-cut

After recovery is done, "b" should be seen.
However, the result shows "a", since the recovery procedure does not enter
recover_dentry due to no dent_mark.

The reason is like below.
- The nid of "a" is checkpointed during #2, f2fs_sync_file.
- The inode page for "b" produced by #3 is written without dent_mark by
sync_node_pages.

So, this patch fixes this bug by assinging file_lost_pino to the "a"'s inode.
If the pino is lost, f2fs_sync_file conducts checkpoint, and then recovers
the latest pino and its dentry information for further recovery.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check bdi->dirty_exceeded when trying to skip data writes

If we don't check the current backing device status, balance_dirty_pages can
fall into infinite pausing routine.

This can be occurred when a lot of directories make a small number of dirty
dentry pages including files.

Reported-by: Brian Chadwick <brianchad@westnet.com.au>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Change-Id: I4b06a9149f4caffbe0749e9f0ac3c41b5692b164
f2fs: Update to proper 3.4 support
msm: mdss: Fix under run on interlace clip play in landscape (squash)

Rotator src rect y co-ordinate is getting odd after de-interlace
calculation but mdss expects even.

Signed-off-by: Pawan Kumar <pavaku@codeaurora.org>

msm: mdss: Avoid variable overloading

A particular variable is overloaded and used in 2 different
contexts. This causes overwriting of original value and leads
to incorrect error handling. This code adds a new variable to
avoid such condition.

Signed-off-by: Shalabh Jain <shalabhj@codeaurora.org>

msm: mdss: Fix mdss iommu detach-attach issue

Move iommu attach logic to rotator play and writeback
queue buffer from overlay_kickoff to make sure iommu is
enable before mapping any buffers.

Signed-off-by: Pawan Kumar <pavaku@codeaurora.org>

msm: mdss: do proper error handling in case of rotator setup fail

When rotator setup fails, the session should only be finished internally
if it hasn't been reported to userspace. At the same time, need to
ensure that proper cleanup of rotator list is happening, through
internal release path.

Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>

msm: mdss: move rotator SMP reservation to rotator setup

Shared memory pool (SMP) blocks are limited, in some cases where there
are many overlay pipes used, we may not be able to get enough blocks for
rotator sessions. In such cases fall-back solution must be considered,
however for this to happen this would need to be identified during
rotator session setup. Move logic to do pipe resource reservation in
rotator setup if possible.

Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>

msm: mdss: Check extra mmb allocated to a pipe

If set call to a pipe changes smp configuration such that
calculated no. of  mmb blocks are less than allocated mmb
blocks, fail this set call. This ensures pipe disconnection
and smp configuration is possible in next commit cycle.
Also, check that no extra mmb is left allocated to any plane
when pipe's format changes. If so, fail the set call to let
correct smp configuration happen in next commit cycle.

Change-Id: I9cef6129142a71ea12037de9d7379a1a9fe97305
Merge "Revert prior f2fs driver and squash CM updates" into kitkat
Revert out all prior audio enhancement configs in favor of CM's update

Change-Id: I1dbbb6e145ea00c768171cc700cf224088c1e92a
ASoC: msm: Squash upstream changes

ASoC: msm: Fix for USB device switch

Add mutex locks to prevent sending multiple mem map
commands unless the previous one returns, because otherwise
the mem_handle is overwritten.

CRs-fixed: 646752
Signed-off-by: Vicky Sehrawat <vickys@codeaurora.org>

ASoC: msm: propagate the error code from the compr driver

Propagate the error code to the upper layers to avoid the
unwanted sequence of the commands to DSP.

CRs-Fixed: 671241
Signed-off-by: Aviral Gupta <aviralg@codeaurora.org>

ASoC: msm: set the master gain to 0 on DSP while configuring

- Mute media volume and play any music clip then reboot
  the phone. Play music again noise comes. This noise
  is introduced in DSP/LPASS.

- DSP suggestion is to mute master volume gain while
  configuring ASM session to avoid such noise at
  begining of asm playback.

Signed-off-by: Ramjee Singh <ramjee@codeaurora.org>

ASoC: msm: Fix for wma playback after SSR

After SSR apr session doesn't get destroyed as
the callback from apr driver doesn't come.Fix
this by not doing NULL allocation in q6asm callback.

Signed-off-by: Anish Kumar <kanish@codeaurora.org>

ASoC: msm: qdsp6v2: clear old memhandle list when SSR happens

When SSR triggers, ASM gets RESET_EVENT callback.
Clear custom topology related old memhandle list here.
Otherwise for next ASM session opened after SSR,
old memhandle is sent to DSP and result in no audio.
Also, for ASM session while unmap during SSR, APR
command fail is expected, even then go ahead and
clear old mem handles relating to session.
Add changes to clear it from list.

CRs-Fixed: 592823, 589762, 592580, 590719, 589450, 593497
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>

ASoC: msm: qdsp6v2: Check for null data pointer

Add check for null data pointer in
aprv2_core_fn_q() and log error message if
true.

CRs-Fixed: 575228
Signed-off-by: Kenneth Westfield <kwestfie@codeaurora.org>

ASoC: msm: qdsp6v2: fix possible integer overflow

Check integer overflow before multiplying struct size. If that happens
should return immediately. In addition if param length is greater than
MAX size from spec, better return error.

CRs-fixed: 605273
Signed-off-by: Fred Oh <fred@codeaurora.org>

ASoC: dapm: Unlock mutex in error cases

Dapm functions are not unlocking the mutex when an error
is encountered.This change fixes the mutex unlock issue.

CRs-fixed: 613644
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>
(cherry picked from commit e5d642a37a643bf9ee4606e0a43b6714019fbc4a)

[SCSI] async: introduce 'async_domain' type

This is in preparation for teaching async_synchronize_full() to sync all
pending async work, and not just on the async_running domain.  This
conversion is functionally equivalent, just embedding the existing list
in a new async_domain type.

The .registered attribute is used in a later patch to distinguish
between domains that want to be flushed by async_synchronize_full()
versus those that only expect async_synchronize_{full|cookie}_domain to
be used for flushing.

[jejb: add async.h to scsi_priv.h for struct async_domain]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Tested-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

ASoC: Cold start latency reduction

This patch parallelizes FE (front end) and BE (back end)
when playback/capture path is set up. FE's and BE's which can
be parallelized should be indicated in corresponding machine file.
All the operations can be started asynchronously provided the usecase
supports asynchronous operation.
Parallelizing reduces the startup latency as both FE and BE opeations
run in parallel.

Signed-off-by: Anish Kumar <kanish@codeaurora.org>

Conflicts:
	sound/soc/soc-pcm.c

ASoC: msm8974: Machine driver async ops change

Asoc framework supports parallelization of operations
which reduces the startup latency. Machine driver will
specify which usecases support parallelization. This
change updates the machine driver to enable the parallelization.

Signed-off-by: Anish Kumar <kanish@codeaurora.org>

ASoC: msm: qdsp6v2: move hw_params into prepare

Asoc framework supports parallelization of operations
which reduces the startup latency.
Moving hw_params into prepare further reduces this start
up latency.

Signed-off-by: Anish Kumar <kanish@codeaurora.org>

ASoC: msm: Add MP2 decode support in compress driver

Add MP2 decoder support to ALSA compressed driver. It
allows user-space application to play MP2 audio data through
QDSP6.

Signed-off-by: Dhananjay Kumar <dhakumar@codeaurora.org>

Conflicts:
	sound/soc/msm/qdsp6v2/msm-compress-q6-v2.c

ASoC: msm: Add support for WMA DSP decode

WMA V9 and WMA Pro tunnel-mode supports are added to
compressed driver. It allows user-space application to
decode WMA V9 and WMA Pro audio stream through QDSP6.

Signed-off-by: Manish Dewangan <manish@codeaurora.org>
Signed-off-by: Dhananjay Kumar <dhakumar@codeaurora.org>

Conflicts:
	sound/soc/msm/qdsp6v2/msm-compress-q6-v2.c

ASoC: msm: Fix wma pro block alignment parameter

The current code assigns and sends the wrong block
alignment information to the adsp because of which wma pro
playback fails. The fix assigns the correct block alignment
information for wma pro.

Signed-off-by: Aravind Kumar <akumark@codeaurora.org>

ASoC: qdsp6: Add MP2 decoder format support

New ASM message format is added to support tunnel-mode MP2
decoder through QDSP6.

Signed-off-by: Dhananjay Kumar <dhakumar@codeaurora.org>

ASoC: msm: qdsp6v2: Update pcm media format block to use correct stream id

Repeat mode is not working in pcm offload path. When two streams
are used in a single session pcm format block should be sent
specific to each stream. Data sent on stream 2 is ignored by DSP
because pcm format block is always sent on stream 1. Fix is to
update pcm media format block to use correct stream id before
data is sent to DSP.

CRs-Fixed: 673510
Signed-off-by: Krishnankutty Kolathappilly <kkolat@codeaurora.org>

ASoC: compress: fix the target not going to TCXO shutdown

The error code propagated from the flush cmd in the trigger stop
is causing the error in the state of the soc compress framework.
This hinders in closing the BE connected to the FE.
If the AFE is not closed it prevents the target to go into TCXO
shutdown.
Fixed by removing the error handling of the flush command in the
trigger stop, since failure in flush doesn't signify the
failure in the stop command.

CRs-Fixed: 687111
Signed-off-by: Aviral Gupta <aviralg@codeaurora.org>

Revert "ASoC: compr: Disable soft-pause for compress playback"

This reverts commit ece021021f54cfe776713d1bbaa6340a735b297f.

Signed-off-by: Scott Mertz <smertz@cyngn.com>

ASoC: msm: Complete the wait_event request when SSR is triggered

LPA platform driver should complete the wait_event request when it
knows that SSR(sub system restart) has happened. There is no point
waiting and bailing out after timeout.

CRs-Fixed: 575060
Signed-off-by: Anish Kumar <kanish@codeaurora.org>

ASoC: msm: qdsp6v2: Add support to improve debug logging

Improve debug logs by adding function names. This
change is required to fix rarely reproducible
customer issues.

Signed-off-by: Anish Kumar <kanish@codeaurora.org>

ASoC: msm: qdsp6v2: update platform driver for new SSR design.

Update PCM platform driver to handle the reset events during
SSR and also unblock the write wait according to
the new SSR design.

CRs-Fixed: 661491
Signed-off-by: Santosh Mardi <gsantosh@codeaurora.org>

ASoC: msm: unblock the calls sent to the driver during SSR

Return error code ENETRESET from the platform driver
during the SSR recovery.
This facilitates the client to handle the error code
and take corrective measures rather than being blocked
on the call.

CRs-Fixed: 683288
Signed-off-by: Aviral Gupta <aviralg@codeaurora.org>

ASoC: msm: qdsp6v2: Fix read error using mmap

When capture session is started in mmap mode then
read commands are issued to ADSP after close command
is issued. This causes read failure as ADSP will not
process the successive read commands after issuing
close command. This change prevents issuing read
command to ADSP when capture session is not in running
state.

Crs-Fixed: 518008
Signed-off-by: Venkat Sudhir <vsudhir@codeaurora.org>

ASoC: msm: qdsp6v2: Add mutex to ensure atomicity

Make sure that afe command sent to DSP is atomic in nature
and doesn't get overwritten in concurrent scenarios.

Signed-off-by: Anish Kumar <kanish@codeaurora.org>

asoc: msm8974: Fix compress capture device name

ASoC: compress: propagate the error code from the compress framework

Propagate the error code from the compress framework for the timestamp
query. This error code will be used by the client to handle the
error case scenarios gracefully.

CRs-Fixed: 683288
Signed-off-by: Aviral Gupta <aviralg@codeaurora.org>

ASoC: msm: qdsp6v2: Userspace interaction cleanup

Compress ioctl function transfers data to/from userspace
and additionally implements logic to process ioctl command.
Ioctl function should delegate the processing to internal
functions for support compat mode.
This change moves the processing into internal function.

Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>

ASoC: core: Add compat support for compress driver

Change adds compat ioctl for supporting 32 bit userspace
client when kernel is compiled for 64 bit.

Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>

asoc: msm8974: Update offload device configuration

 * Actually enable offloading on the extra devices.

ASoC: msm: fix the audio mute issue post SSR

On receiving the RESET_EVENTS the in_count is not incremented
leading to the wait timeout in the capture_copy.
This causes the capture session not to be closed from the client post SSR.
Post SSR, read error causes the state mismatch for the clients
leading to no audio issue.

Signed-off-by: Aviral Gupta <aviralg@codeaurora.org>

ASoC: msm: Check the pointers before memcpy

Check the pointers before memcpy when the application queries
the adsp capability for compressed audio. Invalid pointer
can cause kernel panic when doing memcpy.

CRs-fixed: 665297
Signed-off-by: Kuirong Wang <kuirongw@codeaurora.org>

ASoC: msm: qdsp6v2: add support for device mute

Add support for muting the RX and TX devices without affecting
the voice stream. This feature is added to aid in voice call
quality testing.

CRs-Fixed: 634690
Signed-off-by: Shiv Maliyappanahalli <smaliyap@codeaurora.org>

ASoC: msm: Add support for AAC decode in ADTS format

- Set AAC format based on the format value set in
  compress params
- Default is RAW AAC

Signed-off-by: ApurupaPattapu <apurupa@codeaurora.org>

ASoC: msm: qdsp6v2: Do not free memory that has not been unmapped from DSP

The memory that is not unmapped from DSP should not be used until
DSP clears it. Do not free iom memory if the DSP unmap has
failed.

CRs-fixed: 599780
Signed-off-by: Damir Didjusto <damird@codeaurora.org>

ASoC: msm: qdsp6v2: add check for NULL dereference

The asm loopback driver during close does not check
for NULL before closing the playback and capture
instances.

The change ensures only the valid playback/capture
instances are closed.

CRs-Fixed: 643724
Signed-off-by: Aravind Kumar <akumark@codeaurora.org>

ASoC: msm: fix the target crash due to the NULL pointer dereference

During the close of the FE, the mclk is disabled which accesses the
codec drv data.
In case if the tapan codec was not initialized, then close sequence
will result in the null pointer dereference.
Fix by adding a null check before accessing the codec data structure.

CRs-Fixed: 635065
Signed-off-by: Aviral Gupta <aviralg@codeaurora.org>

ASoC: msm: Use 16K sample rate for RFECNS

To enable record with an RFECNS device use a 16K
sample rate

Signed-off-by: Ben Romberger <bromberg@codeaurora.org>

ASoC: msm: qdsp6v2: Update supported sample rates

Compress driver supports 96Khz and 192Khz sample rates. Change updates
the supported frequencies in the compress driver.

CRs-fixed: 653510
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>

ASoC: msm: qdsp6v2: Add FLAC in compress offload path

Add FLAC format in compress offload driver, and asm
module

Signed-off-by: Apurupa Pattapu <apurupa@codeaurora.org>

ASoC: Fix the sync problem after SSR

After SSR default registers needs to be restored. Then
we need to sync all the registers with cache values. This
fixes the problem where register values got changed
after SSR causing AAC clip playback failure.

CRs-Fixed: 579574
Signed-off-by: Anish Kumar <kanish@codeaurora.org>
Signed-off-by: Fred Oh <fred@codeaurora.org>

ASoC: wcd9320: Add HD2 tuning coefficients for HPH path

Add 2nd Harmonic Distortion (HD2) tuning coefficients
for HPH path. HD2 coefficients get turned ON during HPH
enable and turned OFF during path tear down. Enabling HD2
coefficients would increase the Headphone PA efficiency during
audio playback.

Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>

ASoC: wcd9xxx: Enable headset in high performance

Invoke class AB sequence for headset path dynamically based on
module parameter. Change enables headset path in high performance
mode when module parameter is set to one.

Signed-off-by: Sudheer Papothi <spapothi@codeaurora.org>

ASoC: wcd9xxx: Enable headset in high performance

Invoke class AB mode for headset path when sample rate
is set to 192KHz and bit width is set to 24. Change enables
headset path in Ultra High Quality Audio(UHQA)mode.

Signed-off-by: Sudheer Papothi <spapothi@codeaurora.org>

ASoC: wcd9xxx: Distortion in HPH LO combo device

Follow Class H sequence for headset, lineout and ear concurrency as per
the class H HW design sequence to avoid signal clipping.

CRs-Fixed: 602408,618992
Signed-off-by: Sudheer Papothi <spapothi@codeaurora.org>

ASoC: wcd9xxx: Change in sequence of HPH Rx path

Change HPH Rx path sequence to enable Rx clock and reset Rx interpolator
path before HPH DACs enable to avoid pop during bringup of device path.

CRs-Fixed: 616383
Signed-off-by: Sudheer Papothi <spapothi@codeaurora.org>

ASoC: wcd9320: Change compander parameter for 192Khz playback

Update the meter rate parameter for compander in order to achieve
better performance with Compander support for headphone, lineout
and speaker paths for 192 KHz sampling rate. Update the static gain
offset accordingly depending on the buck voltage requested.

CRs-fixed: 481501
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>

ASoC: msm8974: Set tx bit rate for slim tx params

Set tx bit rate format in slimbus tx hw fixup params.

Change-Id: Ic73d137ce784ab902e4893cc688489ee0fcd8cf3
m8: Update M8 audio machine driver

 * Add async ops support and bugfixes

Change-Id: I75d1441248a629f665f7aeb8825dc2c25d34807c
rcu: Squash upstream changes

rcu: Add RCU_FAST_NO_HZ tracing for idle exit

Traces of rcu_prep_idle events can be confusing because
rcu_cleanup_after_idle() does no tracing.  This commit therefore adds
this tracing.

CRs-fixed: 657837
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Git-commit: 2fdbb31b662787f78bb78b3e4e18f1a072058ffc
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

rcu: Make RCU_FAST_NO_HZ use timer rather than hrtimer

The RCU_FAST_NO_HZ facility uses an hrtimer to wake up a CPU when
it is allowed to go into dyntick-idle mode, which is almost always
cancelled soon after.  This is not what hrtimers are good at, so
this commit switches to the timer wheel.

CRs-fixed: 657837
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Git-commit: 2ee3dc80660ac8285a37e662fd91b2e45c46f06a
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

Conflicts:
	kernel/rcutree_plugin.h

rcu: Make RCU_FAST_NO_HZ account for pauses out of idle

Both Steven Rostedt's new idle-capable trace macros and the RCU_NONIDLE()
macro can cause RCU to momentarily pause out of idle without the rest
of the system being involved.  This can cause rcu_prepare_for_idle()
to run through its state machine too quickly, which can in turn result
in needless scheduling-clock interrupts.

This commit therefore adds code to enable rcu_prepare_for_idle() to
distinguish between an initial entry to idle on the one hand (which needs
to advance the rcu_prepare_for_idle() state machine) and an idle reentry
due to idle-capable trace macros and RCU_NONIDLE() on the other hand
(which should avoid advancing the rcu_prepare_for_idle() state machine).
Additional state is maintained to allow the timer to be correctly reposted
when returning after a momentary pause out of idle, and even more state
is maintained to detect when new non-lazy callbacks have been enqueued
(which may require re-evaluation of the approach to idleness).

CRs-fixed: 657837
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Git-commit: c57afe80db4e169135eb675acc2d241e26cc064e
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

Conflicts:
	kernel/rcutree_plugin.h

rcu: Add warning for RCU_FAST_NO_HZ timer firing

RCU_FAST_NO_HZ uses a timer to limit the time that a CPU with callbacks
can remain in dyntick-idle mode.  This timer is cancelled when the CPU
exits idle, and therefore should never fire.  However, if the timer
were migrated to some other CPU for whatever reason (1) the timer could
actually fire and (2) firing on some other CPU would fail to wake up the
CPU with callbacks, possibly resulting in sluggishness or a system hang.

This commit therfore adds a WARN_ON_ONCE() to the timer handler in order
to detect this condition.

CRs-fixed: 657837
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Git-commit: 79b9a75fb703b6a2670e46b9dc495af5bc7029b3
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

rcu: Ensure that RCU_FAST_NO_HZ timers expire on correct CPU

Timers are subject to migration, which can lead to the following
system-hang scenario when CONFIG_RCU_FAST_NO_HZ=y:

1.	CPU 0 executes synchronize_rcu(), which posts an RCU callback.

2.	CPU 0 then goes idle.  It cannot immediately invoke the callback,
	but there is nothing RCU needs from ti, so it enters dyntick-idle
	mode after posting a timer.

3.	The timer gets migrated to CPU 1.

4.	CPU 0 never wakes up, so the synchronize_rcu() never returns, so
	the system hangs.

This commit fixes this problem by using mod_timer_pinned(), as suggested
by Peter Zijlstra, to ensure that the timer is actually posted on the
running CPU.

CRs-fixed: 657837
Reported-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Git-commit: f511fc624642f0bb8cf65aaa28979737514d4746
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

rcu: Move PREEMPT_RCU preemption to switch_to() invocation

Currently, PREEMPT_RCU readers are enqueued upon entry to the scheduler.
This is inefficient because enqueuing is required only if there is a
context switch, and entry to the scheduler does not guarantee a context
switch.

The commit therefore moves the enqueuing to immediately precede the
call to switch_to() from the scheduler.

CRs-fixed: 657837
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 616c310e83b872024271c915c1b9ab505b9efad9
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

Conflicts:
	kernel/rcutree_plugin.h
	kernel/sched/core.c

rcu: Make exit_rcu() more precise and consolidate

When running preemptible RCU, if a task exits in an RCU read-side
critical section having blocked within that same RCU read-side critical
section, the task must be removed from the list of tasks blocking a
grace period (perhaps the current grace period, perhaps the next grace
period, depending on timing).  The exit() path invokes exit_rcu() to
do this cleanup.

However, the current implementation of exit_rcu() needlessly does the
cleanup even if the task did not block within the current RCU read-side
critical section, which wastes time and needlessly increases the size
of the state space.  Fix this by only doing the cleanup if the current
task is actually on the list of tasks blocking some grace period.

While we are at it, consolidate the two identical exit_rcu() functions
into a single function.

CRs-fixed: 657837
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 9dd8fb16c36178df2066387d2abd44d8b4dca8c8
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[rggupt@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

Conflicts:
	kernel/rcupdate.c

Conflicts:
	include/linux/rcutree.h
	kernel/rcutiny_plugin.h
	kernel/rcutree_plugin.h

rcu: Make RCU_FAST_NO_HZ handle timer migration

The current RCU_FAST_NO_HZ assumes that timers do not migrate unless a
CPU goes offline, in which case it assumes that the CPU will have to come
out of dyntick-idle mode (cancelling the timer) in order to go offline.
This is important because when RCU_FAST_NO_HZ permits a CPU to enter
dyntick-idle mode despite having RCU callbacks pending, it posts a timer
on that CPU to force a wakeup on that CPU.  This wakeup ensures that the
CPU will eventually handle the end of the grace period, including invoking
its RCU callbacks.

However, Pascal Chapperon's test setup shows that the timer handler
rcu_idle_gp_timer_func() really does get invoked in some cases.  This is
problematic because this can cause the CPU that entered dyntick-idle
mode despite still having RCU callbacks pending to remain in
dyntick-idle mode indefinitely, which means that its RCU callbacks might
never be invoked.  This situation can result in grace-period delays or
even system hangs, which matches Pascal's observations of slow boot-up
and shutdown (https://lkml.org/lkml/2012/4/5/142).  See also the bugzilla:

	https://bugzilla.redhat.com/show_bug.cgi?id=806548

This commit therefore causes the "should never be invoked" timer handler
rcu_idle_gp_timer_func() to use smp_call_function_single() to wake up
the CPU for which the timer was intended, allowing that CPU to invoke
its RCU callbacks in a timely manner.

CRs-fixed: 657837
Reported-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Git-commit: 21e52e15666323078b8517a4312712579176b56f
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

rcu: Explicitly initialize RCU_FAST_NO_HZ per-CPU variables

The current initialization of the RCU_FAST_NO_HZ per-CPU variables makes
needless and fragile assumptions about the initial value of things like
the jiffies counter.  This commit therefore explicitly initializes all of
them that are better started with a non-zero value.  It also adds some
comments describing the per-CPU state variables.

CRs-fixed: 657837
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Git-commit: 98248a0e24327bc64eb7518145c44bff7bebebc3
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

rcu: Make rcu_barrier() less disruptive

The rcu_barrier() primitive interrupts each and every CPU, registering
a callback on every CPU.  Once all of these callbacks have been invoked,
rcu_barrier() knows that every callback that was registered before
the call to rcu_barrier() has also been invoked.

However, there is no point in registering a callback on a CPU that
currently has no callbacks, most especially if that CPU is in a
deep idle state.  This commit therefore makes rcu_barrier() avoid
interrupting CPUs that have no callbacks.  Doing this requires reworking
the handling of orphaned callbacks, otherwise callbacks could slip through
rcu_barrier()'s net by being orphaned from a CPU that rcu_barrier() had
not yet interrupted to a CPU that rcu_barrier() had already interrupted.
This reworking was needed anyway to take a first step towards weaning
RCU from the CPU_DYING notifier's use of stop_cpu().

CRs-fixed: 657837
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Git-commit: b1420f1c8bfc30ecf6380a31d0f686884834b599
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

Conflicts:
	kernel/rcutree.c
	kernel/rcutree.h

timer: Fix mod_timer_pinned() header comment

The mod_timer_pinned() header comment states that it prevents timers
from being migrated to a different CPU.  This is not the case, instead,
it ensures that the timer is posted to the current CPU, but does nothing
to prevent CPU-hotplug operations from migrating the timer.

This commit therefore brings the comment header into alignment with
reality.

CRs-fixed: 657837
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Git-commit: 048a0e8f5e1d94c01a5fc70f5b2f2fd2f4527326
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

Conflicts:
	kernel/timer.c

rcu: Update RCU_FAST_NO_HZ tracing for lazy callbacks

In the current code, a short dyntick-idle interval (where there is
at least one non-lazy callback on the CPU) and a long dyntick-idle
interval (where there are only lazy callbacks on the CPU) are traced
identically, which can be less than helpful.  This commit therefore
emits different event traces in these two cases.

CRs-fixed: 657837
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Git-commit: fd4b352687fd8604d49c190c4c9ea9e369fd42d5
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

Conflicts:
	kernel/rcutree_plugin.h

rcu: Move RCU_FAST_NO_HZ per-CPU variables to rcu_dynticks structure

The RCU_FAST_NO_HZ code relies on a number of per-CPU variables.
This works, but is hidden from someone scanning the data structures
in rcutree.h.  This commit therefore converts these per-CPU variables
to fields in the per-CPU rcu_dynticks structures.

CRs-fixed: 657837
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Git-commit: 5955f7eecd77d6b440db278b266cfecdb72ecd00
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

Conflicts:
	kernel/rcutree.h
	kernel/rcutree_plugin.h

rcu: Precompute RCU_FAST_NO_HZ timer offsets

When a CPU is entering dyntick-idle mode, tick_nohz_stop_sched_tick()
calls rcu_needs_cpu() see if RCU needs that CPU, and, if not, computes the
next wakeup time based on the timer wheels.  Only later, when actually
entering the idle loop, rcu_prepare_for_idle() will be invoked.  In some
cases, rcu_prepare_for_idle() will post timers to wake the CPU back up.
But all for naught: The next wakeup time for the CPU has already been
computed, and posting a timer afterwards does not force that wakeup
time to be recomputed.  This means that rcu_prepare_for_idle()'s have
no effect.

This is not a problem on a busy system because something else will wake
up the CPU soon enough.  However, on lightly loaded systems, the CPU
might stay asleep for a considerable length of time.  If that CPU has
a callback that the rest of the system is waiting on, the system might
run very slowly or (in theory) even hang.

This commit avoids this problem by having rcu_needs_cpu() give
tick_nohz_stop_sched_tick() an estimate of when RCU will need the CPU
to wake back up, which tick_nohz_stop_sched_tick() takes into account
when programming the CPU's wakeup time.  An alternative approach is
for rcu_prepare_for_idle() to use hrtimers instead of normal timers,
but timers are much more efficient than are hrtimers for frequently
and repeatedly posting and cancelling a given timer, which is exactly
what RCU_FAST_NO_HZ does.

CRs-fixed: 657837
Reported-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Git-commit: aa9b16306e3243229580ff889cc59fd66bf77973
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

Conflicts:
	kernel/rcutree_plugin.h

Revert "rcu: Move PREEMPT_RCU preemption to switch_to() invocation"

This reverts commit 616c310e83b872024271c915c1b9ab505b9efad9.
(Move PREEMPT_RCU preemption to switch_to() invocation).
Testing by Sasha Levin <levinsasha928@gmail.com> showed that this
can result in deadlock due to invoking the scheduler when one of
the runqueue locks is held.  Because this commit was simply a
performance optimization, revert it.

CRs-fixed: 657837
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
Git-commit: cba6d0d64ee53772b285d0c0c288deefbeaf7775
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

rcu: Stop rcu_do_batch() from multiplexing the "count" variable

Commit b1420f1c (Make rcu_barrier() less disruptive) rearranged the
code in rcu_do_batch(), moving the ->qlen manipulation to follow
the requeueing of the callbacks.  Unfortunately, this rearrangement
clobbered the value of the "count" local variable before the value
of rdp->qlen was adjusted, resulting in the value of rdp->qlen being
inaccurate.  This commit therefore introduces an index variable "i",
avoiding the inadvertent multiplexing.

CRs-fixed: 657837
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Git-commit: b41772abebc27c61dd578b76da99aa5240b4c99a
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ramesh Gupta Guntha <rggupt@codeaurora.org>

Conflicts:
	kernel/rcutree.c

htc: go fuck yourselves

Change-Id: I096d4ca586a04a3229fcd69242d9f38c2395727a
staging: zcache: Squash upstream changes

staging: zcache: fix cleancache race condition with shrinker

commit 6d7d9798ad5c97ee4e911dd070dc12dc5ae55bd0 upstream.

This patch fixes a race condition that results in memory
corruption when using cleancache.

The race exists between the zcache shrinker handler,
shrink_zcache_memory() and cleancache_get_page().

In most cases, the shrinker will both evict a zbpg
from its buddy list and flush it from tmem before a
cleancache_get_page() occurs on that page. A subsequent
cleancache_get_page() will fail in the tmem layer.

In the rare case that two occur together and the
cleancache_get_page() path gets through the tmem
layer before the shrinker path can flush tmem,
zbud_decompress() does a check to see if the zbpg is a
"zombie", i.e. not on a buddy list, which means the shrinker
is in the process of reclaiming it. If the zbpg is a zombie,
zbud_decompress() returns -EINVAL.

However, this return code is being ignored by the caller,
zcache_pampd_get_data_and_free(), which results in the
caller of cleancache_get_page() thinking that the page has
been properly retrieved when it has not.

This patch modifies zcache_pampd_get_data_and_free() to
convey the failure up the stack so that the caller of
cleancache_get_page() knows the page retrieval failed.

This needs to be applied to stable trees as well.
zcache-main.c was named zcache.c before v3.1, so
I'm not sure how you want to handle trees earlier
than that.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

CHROMIUM: UPSTREAM: staging: zram/zcache: swtich Kconfig dependency from X86 to ZSMALLOC

upstream: commit 6e2361720b9da9ec830d407da058ca1827e62b12

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>

BUG=chromium-os:36829
TEST=compile, verify that zram module is updated and /boot/config is correct

Signed-off-by: Luigi Semenzato <semenzato@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/39289
Tested-by: Luigi Semenzato <semenzato@google.com>
Reviewed-by: Sonny Rao <sonnyrao@chromium.org>
Commit-Ready: Luigi Semenzato <semenzato@google.com>

staging: zcache: don't limit number of pools per client

Currently the amount of pools each client can use is limited to 16, this is
and arbitrary limit which isn't really required by current implementation.

This places and arbitrary limit on the number of mounted filesystems that
can use cleancache.

This patch removes that limit and uses IDR to do sparse mapping of pools
in each client.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:
	drivers/staging/zcache/zcache-main.c

staging: zcache: fix refcount leak

In zcache_get_pool_by_id, the refcount of zcache_host is not increased, but
it is always decreased in zcache_put_pool

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: zcache: fix a compile warning

Fix:

drivers/staging/zcache/zcache-main.c: In function ‘zcache_comp_op’:
drivers/staging/zcache/zcache-main.c:112:2: warning: ‘ret’ may be used uninitial

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: zcache: mark zbud_init/zcache_comp_init as __init

These functions are called only when system is initializing, so mark __init
for them to free memory

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: zcache: cleanup zbud_init

Need not set global parameters to 0

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: zcache: optimize zcache_do_preload

zcache_do_preload is called in zcache_put_page where IRQ is disabled, so, need
not care preempt

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: zcache: cleanup zcache_do_preload and zcache_put_page

Cleanup the code for zcache_do_preload and zcache_put_page

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: zcache: introduce get_zcache_client

Introduce get_zcache_client to remove the common code

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: zcache: cleanup the code between tmem_obj_init and tmem_obj_find

tmem_obj_find and insertion tmem-obj have the some logic, we can integrate
the code

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:
	drivers/staging/zcache/tmem.c

defconfig: m8: enable zcache

Conflicts:
	arch/arm/configs/liquid_m8_defconfig

drivers: staging: Fix Zcache

 * Remove dependency on obsolete qcache
 * Fix args for updated zsmalloc

Change-Id: I47835fbacee862917736e0e2164f40e9320a7b06
cpufreq: interactive: Add target_loads_down freq selection

Using a single set of target loads causes an excessive number
of frequency changes.  Reduce by having a mode that allows
for separate load factos for "up" frequency selection and
"down" frequency selection.

If user-space specifies target_loads_down then the new
duel mode frequency selection will be used and frequencies
will be scaled up to meet the load requirements but they
will only be scaled down if the can be scaled down without
violating the down target loads.

If user-space does not store a value in target_loads_down
then this change makes no functional difference in the
governor.

Conflicts:
	drivers/cpufreq/cpufreq_interactive.c

Change-Id: If19cd1d2b48e18ab4f0baf0576f89b765b96a3ee
Revert "intelli_plug: intelligent hotplug cpu driver with eco mode"

This reverts commit 5b05a02e68cf5cfa0e9d5863def604c198f6cae0.

Change-Id: I4cd0c73ffe536eeb9449915dbae07647873e9d7b
Revert "Revert "intelli_plug: intelligent hotplug cpu driver with eco mode""

This reverts commit 78c483051438c802ac993cb8590e9121eba760c6.

Change-Id: Id1bc4f53cf7cb551c1810319be33a6dcc948117e
Merge changes Ib9aba3ce,I37cfb607,I0ec50bd7 into kitkat

* changes:
  Squash intelli_plug v3.8
  sched/cpuidle: reduce IPI storm. Backport upstream 3.16 scheduler updates
  Rebase intelli_plug
Merge "intellidemand: re-introduce intellidemand 5.5 cpu governor" into kitkat
Merge "intellidemand: tweak default settings for MSM8974 SOCs" into kitkat
Revert "staging: zcache: Squash upstream changes"

This reverts commit 13e4bc3bcf0bc24cbd4b7f10f002a149dfb0b11b.

Change-Id: I0558f38c85f4f1175430ad3ee90a28b3842b2714
Merge "Revert "staging: zcache: Squash upstream changes"" into kitkat
Merge "intelliactive: rework input register/unregister" into kitkat
Rebase intelli_plug

Change-Id: I0ec50bd700fa527e5f40f1384f407495406f60d2
sched/cpuidle: reduce IPI storm. Backport upstream 3.16 scheduler updates

Change-Id: I37cfb60788b0d9b31a922b9fcdc72b2cb4975a9b
Squash intelli_plug v3.8

intelli_plug: add profiles support and misc code optimization

bump to version 3.0

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

Intelli_plug: kernel sched/core: add per cpu nr_running stats

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

intelli_plug: use per cpu nr_runnings stats for unplugging cores

bump version to 3.1

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

intelli_plug: allow cpu_nr_running_threshold to be user adjustable

bump version to 3.2

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

intelli_plug: tweak cpu_nr_running threshold

and fix minor logic issues

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

intelli_plug: remove legacy msm_rq based code

just use the original algorithm based on nr_running_stats

bump version to 3.3

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

intelli_plug: add nr_running_thresholds based on thread capacity of SOC type

instead of hard coded nr_running_thresholds, perform compile time calculation
of thresholds based on thread capacity of SOC types.

bump version to 3.4

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

intelli_plug: misc minor code fixup post 3.4 update

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

intelli_plug: add automatic dual-core initializations

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

intelli_plug: deprecate eco mode. replaced by built-in profile

bump version to 3.5

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

intelli_plug: add eco-extreme profile for more dual core use options

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

intelli_plug: post 3.5 tweaks and code clean up

bump to version 3.6

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

intelli_plug: move to its own directory. It's been cross platform for a while

intelli_plug driver has been working on OMAP44xx, TEGRA 3, Exynos and
MSM Krait/Cortex multi-core SOCs.  So it doesn't make sense to patch on a per
SOC basis, move it to its own ARM platform independent folder so patches can
apply to all supported ARM platforms

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

intelli_plug: unify powersuspend and earlysuspend drivers

also minor clean up on the persist logic

bump to version 3.7

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

intelli_plug: adjust thread capacity for Cortex A7 SOCs

Cortex A7 is much weaker than Krait processors

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

intelli_plug: fix thread capacity threshold calculation

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

intelli_plug: fix logic error for eco mode profiles

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

intelli_plug: only apply suspend/resume logic if active

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

intelli_plug: fix incorrect cpufreq API usage

This resolves the wakeup kick and screen off max issues

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

intelli_plug: initialize ip_info struct element during driver init

this will eliminate race issues

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

intelli_plug: use primary CPU's info data for non-boot cpu's settings

Async CPU design has caused quite a bit of grief for controlling cpu
frequencies

bump to version 3.8

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

intelli_plug: older Qualcomm kernel compatibility fixup

ARGH... really angry at CAF code.

some cpufreq driver APIs are incredibly unstable with some of the older
MSM kernels.  The correct way is the fix the cpufreq drivers, but there are
tons of variations out there, so rather than depending on a fix, make
intelli_plug more universal by avoiding the troubling APIs altogether

Change-Id: Ib9aba3ced7ef8ff832174cc8ed094e9287de9bb5