Previously, we use radix tree to index all registered page entries for
atomic file, but now we only use radix tree to see whether current page
is indexed or not, since the other user of radix tree is gone in commit
042b7816aa ("f2fs: remove unnecessary call to invalidate inmemory pages").
So in this patch, we try to use one more efficient way:
Introducing a macro ATOMIC_WRITTEN_PAGE, and setting it as page private
value to indicate page indexing status. By using this way, we can save
memory and lookup time.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We run ltp testcase with f2fs and obtain a TFAIL in diotest4, the result in
detail is as fallow:
dio04
<<<test_start>>>
tag=dio04 stime=1432278894
cmdline="diotest4"
contacts=""
analysis=exit
<<<test_output>>>
diotest4 1 TPASS : Negative Offset
diotest4 2 TPASS : removed
diotest4 3 TFAIL : diotest4.c:129: write allows odd count.returns 1: Success
diotest4 4 TFAIL : diotest4.c:183: Odd count of read and write
diotest4 5 TPASS : Read beyond the file size
......
the result of ext4 with same environment:
dio04
<<<test_start>>>
tag=dio04 stime=1432259643
cmdline="diotest4"
contacts=""
analysis=exit
<<<test_output>>>
diotest4 1 TPASS : Negative Offset
diotest4 2 TPASS : removed
diotest4 3 TPASS : Odd count of read and write
diotest4 4 TPASS : Read beyond the file size
......
The reason is that when triggering DIO in f2fs, we will return zero value
in ->direct_IO if writer's buffer offset, file offset and transfer size is
not alignment to block size of filesystem, resulting in falling back into
buffered write instead of returning -EINVAL.
This patch fixes that problem by returning correct error number for above
case, and removing the judgement condition in check_direct_IO to make sure
the verification will be enabled for direct reader too.
Besides, Jaegeuk Kim pointed out that there is expectional cases we should
always make direct-io falling back into buffered write, such as dio in
encrypted file.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
[Chao Yu make small change and add detail description in commit message]
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
fill_zero can fail due to a lot of reason, but previously we do not handle
its return value, so its callers such as punch_hole/f2fs_zero_range may
report success, but actually can fail because of error occurs inside
fill_zero.
This patch fixes to report correct return value of fill_zero.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When testing with generic/101 in xfstests, error message outputed as below:
--- tests/generic/101.out
+++ results//generic/101.out.bad
@@ -10,10 +10,14 @@
File foo content after log replay:
0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
*
-0200000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+0200000 bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb
*
0372000
...
(Run 'diff -u tests/generic/101.out results/generic/101.out.bad' to see the entire diff)
The test flow is like below:
1. pwrite foo -S 0xaa 0 64K
2. pwrite foo -S 0xbb 64K 61K
3. sync
4. truncate foo 64K
5. truncate foo 125K
6. fsync foo
7. flakey drop writes
8. umount
After this test, we expect the data of recovered file will have the first
64k of data filling with value 0xaa and the next 61k of data filling with
value 0x00 because we have fsynced it before dropping writes in dm.
In f2fs, during recovering, we will only recover the valid block address
in direct node page if it is marked as a fsynced dnode, but block address
which means invalid/reserved (with value NULL_ADDR/NEW_ADDR) will not be
recovered. So, the file recovered shows its incorrect data 0xbb in range of
[61k, 125k].
In this patch, we fix to recover invalid/reserved block during recover flow.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In some cases, we only need the block address when we call
f2fs_reserve_block,
other fields of struct dnode_of_data aren't necessary.
We can try extent cache first for such cases in order to speed up the
process.
Signed-off-by: Fan li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
To avoid meeting garbage data in next free node block at the end of warm
node chain when doing recovery, we will try to zero out that invalid block.
If the device is not support discard, our way for zeroing out block is:
grabbing a temporary zeroed page in meta inode, then, issue write request
with this page.
But, we forget to release that temporary page, so our memory usage will
increase without gaining any hit ratio benefit, so it's better to free it
for saving memory.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In following call path, we will pass a locked and referenced ipage
pointer to get_new_data_page:
- init_inode_metadata
- make_empty_dir
- get_new_data_page
There are two exit paths in get_new_data_page when error occurs:
1) grab_cache_page fails, ipage will not be released;
2) f2fs_reserve_block fails, ipage will be released in callee.
So, it's not consistent for error handling in get_new_data_page.
For f2fs_reserve_block, it's not very easy to change the rule
of error handling, since it's already complicated.
Here we deside to choose an easy way to fix this issue:
If any error occur in get_new_data_page, we will ensure releasing
ipage in this function.
The same issue is in f2fs_convert_inline_dir, fix that too.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Replace BUG_ON with f2fs_bug_on to deal with
block and segment validity check failed.
Signed-off-by: Xue Liu <liuxueliu.liu@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In get_meta_page, we guarantee no failure for the returned page,
but sometimes, IO error from device will incur returning an
non-updated page.
Then, we still use this page as updated one, exception could happen
when using this kind of page.
So in this condition, we'd better freeze fs by making fs readonly and
and stop doing checkpoint.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
some backing devices need pages to be stable during writeback. It doesn't
matter if
the page is completely overwritten or already uptodate, it needs to wait
before write.
Signed-off-by: Fan li <fanofcode.li@samsung.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds to handle error cases in commit_inmem_pages.
If an error occurs, it stops to write the pages and return the error right
away.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When there is no enough free nids in free nid cache, we will try to
readahead FREE_NID_PAGES:4 nat pages into page cache of meta_inode,
then, reading nat entries in nat page for adding free nids to free nid
cache.
But when traversing all nat pages we readaheaded in a circulation,
our exit condition is not set right, one more nat page will be scanned
without readaheading, resulting worse read performance.
This patch fixes to read the correct number nat pages to avoid bad
performance.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If we clear inline data/dentry flag in handle_failed_inode, we will fail
to decline the stat count of inline data/dentry in f2fs_evict_inode due
to no flag in inode. So remove the wrong clearing.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In f2fs_ioc_start_{atomic,volatile}_write, if we failed in converting
inline data, we will report error to user, but still remain atomic/volatile
flag in inode, it will impact further writes for this file. Fix it.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch fixes the incorrect range (0, LONG_MAX) which is used
in ranged fsync. If we use LONG_MAX as the parameter for indicating
the end of file we want to synchronize, in 32-bits architecture
machine, these datas after 4GB offset may not be persisted in
storage after ->fsync returned.
Here, we alter LONG_MAX to LLONG_MAX to fix this issue.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When flushing comes from background, if there is no dirty page in the
mapping of inode, we'd better to skip seeking dirty page from mapping
for writebacking.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The if statement "goto continue_unlock" is exactly the same when
each if condition is true that is depended on the value of both
"step" and "is_cold_data(page)" are 0 or 1. That means when the
value of "step" equals to "is_cold_data(page)", the if condition
is true and the if statement "goto continue_unlock" appears only
once, so it can be optimized to reduce the duplicated code.
Signed-off-by: Tiezhu Yang <kernelpatch@126.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In handle_failed_inode, there is a potential deadlock which can happen
in below call path:
- f2fs_create
- f2fs_lock_op down_read(cp_rwsem)
- f2fs_add_link
- __f2fs_add_link
- init_inode_metadata
- f2fs_init_security failed
- truncate_blocks failed
- handle_failed_inode
- f2fs_truncate
- truncate_blocks(..,true)
- write_checkpoint
- block_operations
- f2fs_lock_all down_write(cp_rwsem)
- f2fs_lock_op down_read(cp_rwsem)
So in this path, we pass parameter to f2fs_truncate to make sure
cp_rwsem in truncate_blocks will not be locked again.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In f2fs_do_collapse, region cp_rwsem covered is large, since it will be
held until all blocks are left shifted, so if we try to collapse small
area at the beginning of large file, checkpoint who want to grab writer's
lock of cp_rwsem will be delayed for long time.
In order to avoid this condition, altering to lock/unlock cp_rwsem each
shift operation.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Add a lookup and a insertion interface for extent tree.
The new lookup return the insert position and the prev/next
extents closest to the offset we lookup when find no match.
The new insertion uses above parameters to improve performance.
There are three possible insertions after the lookup in
f2fs_update_extent_tree, two of them insert parts of removed extent
back to tree, since no merge happens during this process, new insertion
skips the merge check in this scanario; the another insertion inserts a
new extent to tree, new insertion uses prev/next extent and insert
position to insert this extent directly, and save the time of searching
down the tree.
As long as tree remains unchanged between lookup and insertion, this
would work fine. And the new lookup would be useful when add
multi-blocks extent support for insertion interface.
Signed-off-by: Fan li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch changes for a caller to handle the page after its bio gets an error.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Variables for recording extent cache ratio info were updated without
protection, this patch tries to alter them to atomic_t type for more
accurate stat.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds to stat the number of inline xattr inode for
showing in debugfs.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
That encrypted page is used temporarily, so we don't need to mark it accessed.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If there are gced dirty pages and normal dirty pages in the mapping
of one inode, we might writeback them alternately with discontinuous
block address, resulting in low performance.
This patch introduces f2fs_write_cache_pages with codes copied from
write_cache_pages in mm/page-writeback.c.
In this function, we refactor flow with two steps:
1) writeback all cold type pages.
2) writeback all non-cold type pages.
By using this method, f2fs will writeback dirty pages with the same
temperature in bunch mode, it makes writeouted block being with
more continuous address, so they can be merged as much as possible
in f2fs bio cache, and also it will reduce the chance of submiting
small IO from block layer.
Test environment: 8g nokia sd card (very old sd card, but it shows
better effect when testing with this patch, and with a 32g kingston
sd card, I didn't see much more improvement).
Test step:
1. touch testfile;
2. truncate -s 512K testfile;
3. write all pages with odd index;
4. trigger gc by ioctl;
5. write all pages with even index;
6. time fsync testfile.
before:
real 0m0.402s
user 0m0.000s
sys 0m0.000s
after:
real 0m0.143s
user 0m0.004s
sys 0m0.004s
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch fixes to return correct error number of ->setxattr, which
is reported by xfstest tests/generic/026 as below:
generic/026 - output mismatch
--- tests/generic/026.out
+++ results/generic/026.out.bad
@@ -4,6 +4,6 @@
1 below acl max
acl max
1 above acl max
-chacl: cannot set access acl on "largeaclfile": Argument list too long
+chacl: cannot set access acl on "largeaclfile": Numerical result out of range
use 16 aces
use 17 aces
...
Ran: generic/026
Failures: generic/026
Failed 1 of 1 tests
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Previously, since 'commit 4531929e39 ("f2fs: move grabing orphan
pages out of protection region")' was committed, in write_orphan_inodes(),
we will grab all meta page in a batch before we use them under spinlock,
so that we can avoid large time delay of grabbing meta pages under
spinlock.
Now, 'commit d6c67a4fee ("f2fs: revmove spin_lock for
write_orphan_inodes")' remove the spinlock in write_orphan_inodes,
so there is no issue we describe above, we'd better recover to move
the grab operation to original place for readability.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
With cost-benifit method, background gc will consider old section with
fewer valid blocks as candidate victim, these old blocks in section will
be treated as cold data, and laterly will be moved into cold segment.
But if the gcing page is attached by user through buffered or mmaped
write, we should reset the page as non-cold one, because this page may
have more opportunity for further updating.
So fix to add clearing code for the missed 'mmap' case.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When background gc is off, the only way to trigger gc is executing
a force gc in some operations who wants to grab space in disk.
The executing condition is limited: to execute force gc, we should
wait for the time when there is almost no more free section for LFS
allocation. This seems not reasonable for our user who wants to
control triggering gc by himself.
This patch introduces F2FS_IOC_GARBAGE_COLLECT interface for
triggering garbage collection by using ioctl. It provides our users
one more option to trigger gc.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch moves extent cache related code from data.c into extent_cache.c
since extent cache is independent feature, and its codes are not relate to
others in data.c, it's better for us to maintain them in separated place.
There is no functionality change, but several small coding style fixes
including:
* rename __drop_largest_extent to f2fs_drop_largest_extent for exporting;
* rename misspelled word 'untill' to 'until';
* remove unneeded 'return' in the end of f2fs_destroy_extent_tree().
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Since only parts of extents longer than F2FS_MIN_EXTENT_LEN will
be kept in extent cache after split, extents already shorter than
F2FS_MIN_EXTENT_LEN don't need to try split at all.
Signed-off-by: Fan Li <fanofcode.li@samsung.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch fixes to update page flag (e.g. Uptodate/cold flag) in
->write_begin.
Otherwise, page will be non-uptodate when we try to write entire
page, and cold data flag in page will not be clean when gced page
is being rewritten.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If an extent_tree entry has a zero reference count, we can drop it from the
cache in higher priority rather than currently referencing entries.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In ->writepages, we use writepages mutex lock to serialize all block
address allocation and page submitting pairs from different inodes.
This method makes our delayed dirty pages of one inode being written
continously as many as possible.
But there is one problem that we did not submit current cached bio in
protection region of writepages mutex lock, so there is a small chance
that we submit the one of other thread's as below, resulting in
splitting more bios.
thread 1 thread 2
->writepages
lock(writepages)
->write_cache_pages
unlock(writepages)
lock(writepages)
->write_cache_pages
->f2fs_submit_merged_bio
->writepage
unlock(writepages)
fs_mark-6535 [002] .... 2242.270230: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5766152, size = 524288
fs_mark-6536 [000] .... 2242.270361: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5767176, size = 4096
fs_mark-6536 [000] .... 2242.270370: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, NODE, sector = 8138112, size = 4096
fs_mark-6535 [002] .... 2242.270776: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5767184, size = 516096
This may really increase time of block layer works, and may cause
larger IO lantency.
This patch moves the submitting operation into region of writepages
mutex lock to avoid bio splits when concurrently writebacking is
intensive.
my test environment: virtual machine,
intel cpu i5 2500, 8GB size memory, 4GB size ramdisk
time fs_mark -t 16 -L 1 -s 524288 -S 1 -d /mnt/f2fs/
before:
real 0m4.244s
user 0m0.088s
sys 0m12.336s
after:
real 0m3.822s
user 0m0.072s
sys 0m10.760s
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When testing with fs_mark, some blocks were written out as cold
data which were mixed with warm data, resulting in splitting more
bios.
This is because fs_mark will create file with random filename as
below:
559551ee~~~~~~~~15Z29OCC05JCKQP60JQ42MKV
559551ee~~~~~~~~NZAZ6X8OA8LHIIP6XD0L58RM
559551ef~~~~~~~~B15YDSWAK789HPSDZKYTW6WM
559551f1~~~~~~~~2DAE5DPS79785BUNTFWBEMP3
559551f1~~~~~~~~1MYDY0BKSQCJPI32Q8C514RM
559551f1~~~~~~~~YQOTMAOMN5CVRFOUNI026MP4
559551f3~~~~~~~~1WF42LPRTQJNPPGR3EINKMPE
559551f3~~~~~~~~8Y2NRK7CEPPAA02LY936PJPG
They are regarded as cold file since their filename are ended with
multimedia files' extension, but this should be wrong as we only
match the extension of filename, not the whole one.
In this patch, we try to fix the format of multimedia filename to:
"filename + '.' + extension", then we set cold file only its
filename matches the format.
So after this change, it will reduce the probability we set the
wrong cold file, also it helps a little for fs_mark's performance
on f2fs.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds missed trace file in maintainer-ship of f2fs,
so it completes the description of files maintained in f2fs,
and also it allows people to find correct mailing list by using
get_maintainer.pl when only patching the trace file of f2fs.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This makes the function check_dnode have a return type of bool
due to this particular function only ever returning either one
or zero as its return value and changes the name of the function
to is_alive in order to better explain this function's intended
work of checking if a dnode is still in use by the filesystem.
Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
[Jaegeuk Kim: change the return value check for the renamed function]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Because of the extent shrinker or other -ENOMEM scenarios, it cannot guarantee
that the largest extent would be cached in the tree all the time.
Instead of relying on extent_tree, we can simply check the cached one in extent
tree accordingly.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We don't need to handle the duplicate extent information.
The integrated rule is:
- update on-disk extent with largest one tracked by in-memory extent_cache
- destroy extent_tree for the truncation case
- drop per-inode extent_cache by shrinker
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch introduces a shrinker targeting to reduce memory footprint consumed
by a number of in-memory f2fs data structures.
In addition, it newly adds:
- sbi->umount_mutex to avoid data races on shrinker and put_super
- sbi->shruinker_run_no to not revisit objects
Note that the basic implementation was copied from fs/ubifs/shrinker.c
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch relocates cached_en not only to be covered by spin_lock, but also
to set once after checking out completely.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Previously, f2fs_update_extent_cache() updates in-memory extent_cache all the
time, and then finally preserves its up-to-date extent into on-disk one during
f2fs_evict_inode.
But, in the following scenario:
1. mount
2. open & write an extent X
3. f2fs_evict_inode; on-disk extent is X
4. open & update the extent X with Y
5. sync; trigger checkpoint
6. power-cut
after power-on, f2fs should serve extent Y, but we have an on-disk extent X.
This causes a failure on xfstests/311.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch fixes wrong calculation on block address field when an extent is
split.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
For newly added fallocate types, it should convert inline_data before handling
block swapping.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Before iput is called, the inode number used by a bad inode can be reassigned
to other new inode, resulting in any abnormal behaviors on the new inode.
This should not happen for the new inode.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The write_checkpoint can update stat information, so we should destroy the stat
structure after it.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Dirty page can be exist in mapping of newly created symlink, but previously
we did not maintain the counting of dirty page for symlink like we maintained
for regular/directory, so the counting we lookuped should be wrong.
This patch adds missed dirty page counting for symlink to fix this issue.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
