There are three steps to free an extent node:
1) list_del_init, 2)__detach_extent_node, 3) kmem_cache_free
In path f2fs_destroy_extent_tree, 1->2->3 to free a node,
But in path f2fs_update_extent_tree_range, it is 2->1->3.
This patch makes all the order to be: 1->2->3
It makes sense, since in the next patch, we import a victim list in the
path shrink_extent_tree, we could check if the extent_node is in the victim
list by checking the list_empty(). So it is necessary to put 1) first.
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
variable nsearched in get_victim_by_default() indicates the number of
dirty segments we already checked. There are 2 problems about the way
it updates:
1. When p.ofs_unit is greater than 1, the victim we find consists
of multiple segments, possibly more than 1 dirty segment.
But nsearched always increases by 1.
2. If segments have been found but not been chosen, nsearched won't
increase. So even we have checked all dirty segments, nsearched
may still less than p.max_search.
All these problems could cause unnecessary search after all dirty
segments have already been checked.
Signed-off-by: Fan li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
no need to wait inline file page writeback for no one
use it, so this patch delete unnecessary wait.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In write_begin, if storage supports stable_page, we don't need to wait for
writeback to update its contents.
This patch introduces to use wait_for_stable_page instead of
wait_on_page_writeback.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If we configure section consist of multiple segments, foreground GC will
do the garbage collection with following approach:
for each segment in victim section
blk_start_plug
for each valid block in segment
write out by OPU method
submit bio cache <---
blk_finish_plug <---
There are two issue:
1) for most of the time, 'submit bio cache' will break the merging in
current bio buffer from writes of next segments, making a smaller bio
submitting.
2) block plug only cover IO submitting in one segment, which reduce
opportunity of merging IOs in plug with multiple segments.
So refactor the code as below structure to strive for biggest
opportunity of merging IOs:
blk_start_plug
for each segment in victim section
for each valid block in segment
write out by OPU method
submit bio cache
blk_finish_plug
Test method:
1. mkfs.f2fs -s 8 /dev/sdX
2. touch 32 files
3. write 2M data into each file
4. punch 1.5M data from offset 0 for each file
5. trigger foreground gc through ioctl
Before patch, there are totoally 40 bios submitted.
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 65536, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 65776, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 66016, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 66256, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 66496, size = 32768
----repeat for 8 times
After patch, there are totally 35 bios submitted.
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 65536, size = 122880
----repeat 34 times
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 73696, size = 16384
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If end_io gets an error, we don't need to set the page as dirty, since we
already set f2fs_stop_checkpoint which will not flush any data.
This will resolve the following warning.
======================================================
[ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ]
4.4.0+ #9 Tainted: G O
------------------------------------------------------
xfs_io/26773 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
(&(&sbi->inode_lock[i])->rlock){+.+...}, at: [<ffffffffc025483f>] update_dirty_page+0x6f/0xd0 [f2fs]
and this task is already holding:
(&(&q->__queue_lock)->rlock){-.-.-.}, at: [<ffffffff81396ea2>] blk_queue_bio+0x422/0x490
which would create a new lock dependency:
(&(&q->__queue_lock)->rlock){-.-.-.} -> (&(&sbi->inode_lock[i])->rlock){+.+...}
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In write_begin, if there is an inline_data, f2fs loads it into 0'th data page.
Since it's the read path, we don't need to sync its inode page.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In write_end, we don't need to sync inode page at every time.
Instead, we can expect f2fs_write_inode will update later.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The sceanrio is:
1. create fully node blocks
2. flush node blocks
3. write inline_data for all the node blocks again
4. flush node blocks redundantly
So, this patch tries to flush inline_data when flushing node blocks.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The scenario is:
1. create lots of node blocks
2. sync
3. write lots of inline_data
-> got panic due to no free space
In that case, we should flush node blocks when writing inline_data in #3,
and trigger gc as well.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If there are many writepages calls by multiple threads in background, we don't
need to serialize to merge all the bios, since it's background.
In such the case, it'd better to run writepages concurrently.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
get_new_segment starts from current segment position, tries to search a
free segment among its right neighbors locate in same section.
But previously our search area was set as [current segment, max segment],
which means we have to search to more bits in free_segmap bitmap for some
worse cases. So here we correct the search area to [current segment, last
segment in section] to avoid unnecessary searching.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch exports a new sysfs entry 'dirty_nat_ratio' to control threshold
of dirty nat entries, if current ratio exceeds configured threshold,
checkpoint will be triggered in f2fs_balance_fs_bg for flushing dirty nats.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When testing f2fs with xfstest, generic/251 is stuck for long time,
the case uses below serials to obtain fresh released space in device,
in order to prepare for following fstrim test.
1. rm -rf /mnt/dir
2. mkdir /mnt/dir/
3. cp -axT `pwd`/ /mnt/dir/
4. goto 1
During preparing step, all nat entries will be cached in nat cache,
most of them are dirty entries with invalid blkaddr, which means
nodes related to these entries have been truncated, and they could
be reused after the dirty entries been checkpointed.
However, there was no checkpoint been triggered, so nid allocators
(e.g. mkdir, creat) will run into long journey of iterating all NAT
pages, looking for free nids in alloc_nid->build_free_nids.
Here, in f2fs_balance_fs_bg we give another chance to do checkpoint
to flush nat entries for reusing them in free nid cache when dirty
entry count exceeds 10% of max count.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Operations in is_merged_page is related to inner bio cache, move it to
data.c.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).
Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg. For the list, see below:
- threadinfo
- task_struct
- task_delay_info
- pid
- cred
- mm_struct
- vm_area_struct and vm_region (nommu)
- anon_vma and anon_vma_chain
- signal_struct
- sighand_struct
- fs_struct
- files_struct
- fdtable and fdtable->full_fds_bits
- dentry and external_name
- inode for all filesystems. This is the most tedious part, because
most filesystems overwrite the alloc_inode method.
The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds. Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull f2fs updates from Jaegeuk Kim:
"This series adds two ioctls to control cached data and fragmented
files. Most of the rest fixes missing error cases and bugs that we
have not covered so far. Summary:
Enhancements:
- support an ioctl to execute online file defragmentation
- support an ioctl to flush cached data
- speed up shrinking of extent_cache entries
- handle broken superblock
- refector dirty inode management infra
- revisit f2fs_map_blocks to handle more cases
- reduce global lock coverage
- add detecting user's idle time
Major bug fixes:
- fix data race condition on cached nat entries
- fix error cases of volatile and atomic writes"
* tag 'for-f2fs-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (87 commits)
f2fs: should unset atomic flag after successful commit
f2fs: fix wrong memory condition check
f2fs: monitor the number of background checkpoint
f2fs: detect idle time depending on user behavior
f2fs: introduce time and interval facility
f2fs: skip releasing nodes in chindless extent tree
f2fs: use atomic type for node count in extent tree
f2fs: recognize encrypted data in f2fs_fiemap
f2fs: clean up f2fs_balance_fs
f2fs: remove redundant calls
f2fs: avoid unnecessary f2fs_balance_fs calls
f2fs: check the page status filled from disk
f2fs: introduce __get_node_page to reuse common code
f2fs: check node id earily when readaheading node page
f2fs: read isize while holding i_mutex in fiemap
Revert "f2fs: check the node block address of newly allocated nid"
f2fs: cover more area with nat_tree_lock
f2fs: introduce max_file_blocks in sbi
f2fs crypto: check CONFIG_F2FS_FS_XATTR for encrypted symlink
f2fs: introduce zombie list for fast shrinking extent trees
...
Pull misc vfs updates from Al Viro:
"All kinds of stuff. That probably should've been 5 or 6 separate
branches, but by the time I'd realized how large and mixed that bag
had become it had been too close to -final to play with rebasing.
Some fs/namei.c cleanups there, memdup_user_nul() introduction and
switching open-coded instances, burying long-dead code, whack-a-mole
of various kinds, several new helpers for ->llseek(), assorted
cleanups and fixes from various people, etc.
One piece probably deserves special mention - Neil's
lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets
called without ->i_mutex and tries to avoid ever taking it. That, of
course, means that it's not useful for any directory modifications,
but things like getting inode attributes in nfds readdirplus are fine
with that. I really should've asked for moratorium on lookup-related
changes this cycle, but since I hadn't done that early enough... I
*am* asking for that for the coming cycle, though - I'm going to try
and get conversion of i_mutex to rwsem with ->lookup() done under lock
taken shared.
There will be a patch closer to the end of the window, along the lines
of the one Linus had posted last May - mechanical conversion of
->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
inode_is_locked()/inode_lock_nested(). To quote Linus back then:
-----
| This is an automated patch using
|
| sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
| sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
| sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
| sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
| sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
|
| with a very few manual fixups
-----
I'm going to send that once the ->i_mutex-affecting stuff in -next
gets mostly merged (or when Linus says he's about to stop taking
merges)"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
nfsd: don't hold i_mutex over userspace upcalls
fs:affs:Replace time_t with time64_t
fs/9p: use fscache mutex rather than spinlock
proc: add a reschedule point in proc_readfd_common()
logfs: constify logfs_block_ops structures
fcntl: allow to set O_DIRECT flag on pipe
fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
fs: xattr: Use kvfree()
[s390] page_to_phys() always returns a multiple of PAGE_SIZE
nbd: use ->compat_ioctl()
fs: use block_device name vsprintf helper
lib/vsprintf: add %*pg format specifier
fs: use gendisk->disk_name where possible
poll: plug an unused argument to do_poll
amdkfd: don't open-code memdup_user()
cdrom: don't open-code memdup_user()
rsxx: don't open-code memdup_user()
mtip32xx: don't open-code memdup_user()
[um] mconsole: don't open-code memdup_user_nul()
[um] hostaudio: don't open-code memdup_user()
...
This patch fixes wrong decision for avaliable_free_memory.
The return valus is already set as false, so we should consider true condition
below only.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds last time that user requested filesystem operations.
This information is used to detect whether system is idle or not later.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Pull vfs xattr updates from Al Viro:
"Andreas' xattr cleanup series.
It's a followup to his xattr work that went in last cycle; -0.5KLoC"
* 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
xattr handlers: Simplify list operation
ocfs2: Replace list xattr handler operations
nfs: Move call to security_inode_listsecurity into nfs_listxattr
xfs: Change how listxattr generates synthetic attributes
tmpfs: listxattr should include POSIX ACL xattrs
tmpfs: Use xattr handler infrastructure
btrfs: Use xattr handler infrastructure
vfs: Distinguish between full xattr names and proper prefixes
posix acls: Remove duplicate xattr name definitions
gfs2: Remove gfs2_xattr_acl_chmod
vfs: Remove vfs_xattr_cmp
If there are no nodes in extent tree, let's skip releasing step to avoid
any overhead of grabbing/releasing extent tree lock.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
1. rename field in struct extent_tree from count to node_cnt for
readability.
2. alter to use atomic type for node_cnt.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch fixes to teach f2fs_fiemap to recognize encrypted data.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There are duplicated code in between get_node_page and get_node_page_ra,
introduce __get_node_page to includes common parts of these two, and
export get_node_page and get_node_page_ra by reusing __get_node_page.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Add node id check in ra_node_page and get_node_page_ra like get_node_page.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
make sure the isize we read doesn't change during the process.
Signed-off-by: Fan li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There was a subtle bug on nat cache management which incurs wrong nid allocation
or wrong block addresses when try_to_free_nats is triggered heavily.
This patch enlarges the previous coverage of nat_tree_lock to avoid data race.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Introduce max_file_blocks in sbi to store max block index of file in f2fs,
it could be used to avoid unneeded calculation of max block index in
runtime.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: fix overflow of sbi->max_file_blocks]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Add missed CONFIG_F2FS_FS_XATTR for encrypted symlink inode in order
to avoid unneeded registry of ->{get,set,remove}xattr.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch removes refcount, and instead, adds zombie_list to shrink directly
without radix tree traverse.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch fixes missing IPU condition when fdatasync is called.
With this patch, fdatasync is able to avoid additional node writes for recovery.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There is no report on this bug_on case, but if malicious attacker changed this
field intentionally, we can just reset it as a MAX value.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There are two rules to handle aborting volatile or atomic writes.
1. drop atomic writes
- we don't need to keep any stale db data.
2. write journal data
- we should keep the journal data with fsync for db recovery.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If filesystem is readonly, leave user message info instead of recovering
inline dot inode.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Otherwise, we can get mismatched largest extent information.
One example is:
1. mount f2fs w/ extent_cache
2. make a small extent
3. umount
4. mount f2fs w/o extent_cache
5. update the largest extent
6. umount
7. mount f2fs w/ extent_cache
8. get the old extent made by #2
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Use f2fs_sync_fs to clean up codes in f2fs_ioc_write_checkpoint.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: remove unused err variable]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds a max block check for get_data_block_bmap.
Trinity test program will send a block number as parameter into
ioctl_fibmap, which will be used in get_node_path(), when the block
number large than f2fs max blocks, it will trigger kernel bug.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Xue Liu <liuxueliu.liu@huawei.com>
[Jaegeuk Kim: fix missing condition, pointed by Chao Yu]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
fix bugs:
1. len could be updated incorrectly when start+len is beyond isize.
2. If there is a hole consisting of more than two blocks, it could
fail to add FIEMAP_EXTENT_LAST flag for the last extent.
3. If there is an extent beyond isize, when we search extents in a range
that ends at isize, it will also return the extent beyond isize,
which is outside the range.
Signed-off-by: Fan li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Sometimes we keep dumb when IO error occur in lower layer device, so user
will not receive any error return value for some operation, but actually,
the operation did not succeed.
This sould be avoided, so this patch reports such kind of error to user.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
__recover_do_dentries will try to grab free space in storage, so fix to
add missing f2fs_balance_fs here.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If f2fs_write_begin is to update data, we can bypass calling f2fs_lock_op() in
order to avoid the checkpoint latency in the write syscall.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If get_node_page() gets zero nid, we can return early without getting a wrong
page. For example, get_dnode_of_data() can try to do that.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds prepare_write_begin to clean f2fs_write_begin.
The major role of this function is to convert any inline_data and allocate
or find block address.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If inline_data option is disable, when truncating an inline inode with
size which is not exceed maxinum inline size, we should not convert
inline inode to regular one to avoid the overhead of synchronizing
conversion.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
do_checkpoint and write_checkpoint can fail due to reasons like triggering
in a readonly fs or encountering IO error of storage device.
So it's better to report such error info to user, let user be aware of
failure of doing checkpoint.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If user tries to update or read data, we don't need to call f2fs_balance_fs
which triggers f2fs_gc, which increases unnecessary long latency.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Only cover sbi->cp_rwsem on one dnode page's allocation and modification
instead of multiple's in f2fs_map_blocks, it can reduce the covered region
of cp_rwsem, then we can avoid potential long time delay for concurrent
checkpointer.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch introduces recording node block allocation in dnode_of_data.
This information helps to figure out whether any node block is allocated during
specific file operations.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The f2fs_balance_fs doesn't need to cover f2fs_new_inode or f2fs_find_entry
works.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We can check inode's inline_data flag when calling to convert it.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If there is no candidates for shrinking slab entries, we don't need to traverse
any trees at all.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: fix missing initialization reported by Yunlei He]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
It would be better to use atomic variable for total_extent_tree.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
check map->m_len right after it changes to avoid excess call
to update dnode_of_data.
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>
Previously, when finishing a checkpoint, we have persisted all fs meta
info including meta inode, node inode, dentry page of directory inode, so,
after a sudden power cut, f2fs can recover from last checkpoint with full
directory structure.
But during checkpoint, we didn't flush dirty pages of regular and symlink
inode, so such dirty datas still in memory will be lost in that moment of
power off.
In order to reduce the chance of lost data, this patch enables
f2fs_balance_fs_bg with the ability of data flushing. It will try to flush
user data before starting a checkpoint. So user's data written after last
checkpoint which may not be fsynced could be saved.
When we mount with data_flush option, after every period of cp_interval
(could be configured in sysfs: /sys/fs/f2fs/device/cp_interval) seconds
user data could be flushed into device once f2fs_balance_fs_bg was called
in kworker thread or gc thread.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Add to stat dirty regular and symlink inode for showing in debugfs.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Add a new option 'data_flush' to enable data flush functionality.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Maintain regular/symlink inode which has dirty pages in global dirty list
and record their total dirty pages count like the way of handling directory
inode.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Introduce __f2fs_commit_super to include duplicated codes in
f2fs_commit_super for cleanup.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We have already got one copy of valid super block in memory, do not grab
buffer header of super block all the time.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs use fields of f2fs_super_block struct directly in a grabbed buffer.
Once the buffer happen to be destroyed (e.g. through dd), it may bring
in unpredictable effect on f2fs.
This patch fixes to allocate additional buffer to store datas of super
block rather than using grabbed block buffer directly.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs_map_blocks will set m_flags and m_len to 0, so we don't need to
reset m_flags ourselves, but have to reset m_len to correct value
before use it again.
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>
Introduce __remove_dirty_inode to clean up codes in remove_dirty_dir_inode.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Add a new dirt list node member in inode info for linking the inode to
global dirty list in superblock, instead of old implementation which
allocate slab cache memory as an entry to inode.
It avoids memory pressure due to slab cache allocation, and also makes
codes more clean.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
remove_dirty_dir_inode will be renamed to remove_dirty_inode as a generic
function in following patch for removing directory/regular/symlink inode
in global dirty list.
Here rename ino management related functions for readability, also in
order to avoid name conflict.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
map.m_len should be reduced after skip a block
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>
@lend of filemap_write_and_wait_range is supposed to be a "offset
in bytes where the range ends (inclusive)". Subtract 1 to avoid
writing an extra page.
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>
If read_node_page return LOCKED_PAGE, in its caller it's better a) skip
unneeded 'Update' flag and mapping info verfication; b) check nid value
stored in footer structure of node page.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Change the list operation to only return whether or not an attribute
should be listed. Copying the attribute names into the buffer is moved
to the callers.
Since the result only depends on the dentry and not on the attribute
name, we do not pass the attribute name to list operations.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Previously, f2fs_commit_super hacks the bh->blocknr to write the broken
alternate superblock.
Instead of it, we should use the correct logic to retrieve its buffer head
with locking it appropriately.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch enhances the existing bit operation when f2fs allocates SSR
blocks.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
new method: ->get_link(); replacement of ->follow_link(). The differences
are:
* inode and dentry are passed separately
* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.
It's a flagday change - the old method is gone, all in-tree instances
converted. Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode. That'll change
in the next commits.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.
new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases. page_follow_link_light()
instrumented to yell about anything missed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add an additional "name" field to struct xattr_handler. When the name
is set, the handler matches attributes with exactly that name. When the
prefix is set instead, the handler matches attributes with the given
prefix and with a non-empty suffix.
This patch should avoid bugs like the one fixed in commit c361016a in
the future.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In commit 3c45414527 ("f2fs: do not trim preallocated blocks when
truncating after i_size"), in order to follow the regulation: "truncate(x)
where x > i_size will not trim all blocks past i_size." like other file
systems, in ->setattr we invoked truncate_setsize instead of f2fs_truncate
to avoid unneeded block trimming in such case, but forgot to call
f2fs_convert_inline_inode keep consistency of inline data conversion rule.
This patch fixes to convert inline data if necessary.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Use sbi->blocks_per_seg directly to avoid unnecessary calculation when using
1 << sbi->log_blocks_per_seg.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
For direct IO, f2fs only allocate new address for the block which is not
exist in the disk before, its mapping info should not exist in extent
cache previously, so here we do not need to call f2fs_drop_largest_extent
to drop related cache.
Due to no more callers for f2fs_drop_largest_extent now, kill it.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In recover_data, value of argument 'type' will be CURSEG_WARM_NODE all
the time, remove it for cleanup.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Clean up codes in lookup_journal_in_cursum() with __has_cursum_space().
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If device does not support discard, some obsolete dnodes can be recovered
by roll-forward. This patch enhances the recovery flow.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
While handling extent trees, we can enter into a reclaiming path anytime.
If it tries to release some extent nodes in the same extent tree,
write_lock(&et->lock) would be hanged.
In order to avoid the deadlock, we can just skip it.
Note that, if it is an unreferenced tree, we should get write_lock(&et->lock)
successfully and release all of therein nodes.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
get_lock_data_page in f2fs_readdir can fail due to a lot of reasons (i.e.
no memory or IO error...), it's better to report this kind of error to
user rather than ignoring it.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We should clear uptodate flag for all pages atomic written when we drop
them, otherwise before these cached pages were reclaimed or invalidated
eventually, we will see invalid data when hitting them again.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
1. Skip __reverse_ulong if the bitmap is empty.
2. Reduce branches and codes.
According to my test, the performance of this new version is 5% higher on
an empty bitmap of 64bytes, and remains about the same in the worst scenario.
Signed-off-by: Fan li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If last dirty dentry page was writebacked in reclaim path, we should
remove its directory inode from global dirty list to avoid unnecessary
flush for this inode when doing checkpoint.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In 64-bit kernel f2fs can supports 32-bit ioctl system call by identifying
encoded code which is converted from 32-bit one to 64-bit one in
->compat_ioctl.
When we introduced new interfaces in ->ioctl, we forgot to enable them in
->compat_ioctl, so enable them for fixing.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: fix wrongly added spaces together]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch introduces a new ioctl F2FS_IOC_DEFRAGMENT to support file
defragment in a specified range of regular file.
This ioctl can be used in very limited workload: if user expects high
sequential read performance in randomly written file, this interface
can be used for defragmentation, after that file can be written as
continuous as possible in the device.
Meanwhile, it has side-effect, it will make holes in segments where
blocks located originally, so it's better to trigger GC to eliminate
fragment in segments.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We should always commit atomic written pages in LFS mode, otherwise data
will become corrupted if we encounter suddent power cut after partial
pages committed in IPU mode.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs_create_root_stats can fail due to no memory, report it to user.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Now that the xattr handler is passed to the xattr handler operations, we
have access to the attribute name prefix, so simplify
f2fs_xattr_generic_list.
Also, f2fs_xattr_advise_list is only ever called for
f2fs_xattr_advise_handler; there is no need to double check for that.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Changman Lee <cm224.lee@samsung.com>
Cc: Chao Yu <chao2.yu@samsung.com>
Cc: linux-f2fs-devel@lists.sourceforge.net
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The xattr_handler operations are currently all passed a file system
specific flags value which the operations can use to disambiguate between
different handlers; some file systems use that to distinguish the xattr
namespace, for example. In some oprations, it would be useful to also have
access to the handler prefix. To allow that, pass a pointer to the handler
to operations instead of the flags value alone.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
new_valid_dev() always returns 1, so the !new_valid_dev() check is not
needed. Remove it.
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Changman Lee <cm224.lee@samsung.com>
Cc: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull security subsystem update from James Morris:
"This is mostly maintenance updates across the subsystem, with a
notable update for TPM 2.0, and addition of Jarkko Sakkinen as a
maintainer of that"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (40 commits)
apparmor: clarify CRYPTO dependency
selinux: Use a kmem_cache for allocation struct file_security_struct
selinux: ioctl_has_perm should be static
selinux: use sprintf return value
selinux: use kstrdup() in security_get_bools()
selinux: use kmemdup in security_sid_to_context_core()
selinux: remove pointless cast in selinux_inode_setsecurity()
selinux: introduce security_context_str_to_sid
selinux: do not check open perm on ftruncate call
selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default
KEYS: Merge the type-specific data with the payload data
KEYS: Provide a script to extract a module signature
KEYS: Provide a script to extract the sys cert list from a vmlinux file
keys: Be more consistent in selection of union members used
certs: add .gitignore to stop git nagging about x509_certificate_list
KEYS: use kvfree() in add_key
Smack: limited capability for changing process label
TPM: remove unnecessary little endian conversion
vTPM: support little endian guests
char: Drop owner assignment from i2c_driver
...
In f2fs_shrink_extent_tree we should stop shrink flow if we have already
shrunk enough nodes in extent cache.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Now, in ->symlink of f2fs, we kept the fixed invoking order between
f2fs_add_link and page_symlink since we should init node info firstly
in f2fs_add_link, then such node info can be used in page_symlink.
But we didn't fix to release meta info which was done before page_symlink
in our error path, so this will leave us corrupt symlink entry in its
parent's dentry page. Fix this issue by adding f2fs_unlink in the error
path for removing such linking.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Atomic write page can be GCed, after committing this kind of page, we should
clear the GCed flag for it.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If we got failure during commit_atomic_write, abort_volatile_write will be
called, but will not drop the inmemory pages due to no FI_ATOMIC_FILE.
Actually, there is no reason to check the flag in abort_volatile_write.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Users expect bmap will give allocated block addresses.
Let's play likewise ext4.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Once f2fs_gc is done, wait_ms is changed once more.
So, its tracepoint would be located after it.
Reported-by: He YunLei <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
different competitors
Since we use different page cache (normally inode's page cache for R/W
and meta inode's page cache for GC) to cache the same physical block
which is belong to an encrypted inode. Writeback of these two page
cache should be exclusive, but now we didn't handle writeback state
well, so there may be potential racing problem:
a)
kworker: f2fs_gc:
- f2fs_write_data_pages
- f2fs_write_data_page
- do_write_data_page
- write_data_page
- f2fs_submit_page_mbio
(page#1 in inode's page cache was queued
in f2fs bio cache, and be ready to write
to new blkaddr)
- gc_data_segment
- move_encrypted_block
- pagecache_get_page
(page#2 in meta inode's page cache
was cached with the invalid datas
of physical block located in new
blkaddr)
- f2fs_submit_page_mbio
(page#1 was submitted, later, page#2
with invalid data will be submitted)
b)
f2fs_gc:
- gc_data_segment
- move_encrypted_block
- f2fs_submit_page_mbio
(page#1 in meta inode's page cache was
queued in f2fs bio cache, and be ready
to write to new blkaddr)
user thread:
- f2fs_write_begin
- f2fs_submit_page_bio
(we submit the request to block layer
to update page#2 in inode's page cache
with physical block located in new
blkaddr, so here we may read gabbage
data from new blkaddr since GC hasn't
writebacked the page#1 yet)
This patch fixes above potential racing problem for encrypted inode.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
After finishing building free nid cache, we will try to readahead
asynchronously 4 more pages for the next reloading, the count of
readahead nid pages is fixed.
In some case, like SMR drive, read less sectors with fixed count
each time we trigger RA may be low efficient, since we will face
high seeking overhead, so we'd better let user to configure this
parameter from sysfs in specific workload.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When there is no free nid in nid cache, all new node allocaters stop their
job to wait for reloading of free nids, however reloading is synchronous as
we will read 4 NAT pages for building nid cache, it cause the long latency.
This patch tries to readahead more NAT pages with READA request flag after
reloading of free nids. It helps to improve performance when users allocate
node id intensively.
Env: Sandisk 32G sd card
time for i in `seq 1 60000`; { echo -n > /mnt/f2fs/$i; echo XXXXXX > /mnt/f2fs/$i;}
Before:
real 0m2.814s
user 0m1.220s
sys 0m1.536s
After:
real 0m2.711s
user 0m1.136s
sys 0m1.568s
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Now, we use ra_meta_pages to reads continuous physical blocks as much as
possible to improve performance of following reads. However, ra_meta_pages
uses a synchronous readahead approach by submitting bio with READ, as READ
is with high priority, it can not be used in the case of preloading blocks,
and it's not sure when these RAed pages will be used.
This patch supports asynchronous readahead in ra_meta_pages by tagging bio
with READA flag in order to allow preloading.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In recovery or checkpoint flow, we grab pages temperarily in meta inode's
mapping for caching temperary data, actually, datas in these pages were
not meta data of f2fs, but still we tag them with REQ_META flag. However,
lower device like eMMC may do some optimization for data of such type.
So in order to avoid wrong optimization, we'd better remove such flag
for temperary non-meta pages.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds a tracepoint for f2fs_read_data_pages to trace when pages
are readahead by VFS.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
For normal inodes, their pages are allocated with __GFP_FS, which can cause
filesystem calls when reclaiming memory.
This can incur a dead lock condition accordingly.
So, this patch addresses this problem by introducing
f2fs_grab_cache_page(.., bool for_write), which calls
grab_cache_page_write_begin() with AOP_FLAG_NOFS.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The f2fs_collapse_range and f2fs_insert_range changes the block addresses
directly. But that can cause uncovered SSA updates.
In that case, we need to give up to change the block addresses and do buffered
writes to keep filesystem consistency.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The periodic checkpoint can resolve the previous issue.
So, now we can use this again to improve the reported performance regression:
https://lkml.org/lkml/2015/10/8/20
This reverts commit 15bec0ff5a9ba6d203178fa8772259df6207942a.
This patch introduces F2FS_GOING_DOWN_METAFLUSH which flushes meta pages like
SSA blocks and then blocks all the writes.
This can be used by power-failure tests.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch introduces a periodic checkpoint feature.
Note that, this is not enforcing to conduct checkpoints very strictly in terms
of trigger timing, instead just hope to help user experiences.
The default value is 60 seconds.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch introduces a tracepoint to monitor background gc behaviors.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch introduce a new ioctl for those users who want to trigger
checkpoint from userspace through ioctl.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch drops in batches gc triggered through ioctl, since user
can easily control the gc by designing the loop around the ->ioctl.
We support synchronous gc by forcing using FG_GC in f2fs_gc, so with
it, user can make sure that in this round all blocks gced were
persistent in the device until ioctl returned.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When searching victim during gc, if there are no dirty segments in
filesystem, we will still take the time to search the whole dirty segment
map, it's not needed, it's better to skip in this condition.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
When doing gc, we search a victim in dirty map, starting from position of
last victim, we will reset the current searching position until we touch
the end of dirty map, and then search the whole diryt map. So sometimes we
will search the range [victim, last] twice, it's redundant, this patch
avoids this issue.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Our hit stat of extent cache will increase all the time until remount,
and we use atomic_t type for the stat variable, so it may easily incur
overflow when we query extent cache frequently in a long time running
fs.
So to avoid that, this patch uses atomic64_t for hit stat variables.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
