Commit Graph

368 Commits

Author SHA1 Message Date
Hou Pengyang
201ef5e080 f2fs: improve shrink performance of extent nodes
On the worst case, we need to scan the whole radix tree and every rb-tree to
free the victimed extent_nodes when shrinking.

Pengyang initially introduced a victim_list to record the victimed extent_nodes,
and free these extent_nodes by just scanning a list.

Later, Chao Yu enhances the original patch to improve memory footprint by
removing victim list.

The policy of lru list shrinking becomes:
1) lock lru list's lock
2) trylock extent tree's lock
3) remove extent node from lru list
4) unlock lru list's lock
5) do shrink
6) repeat 1) to 5)

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-02-22 16:07:23 -08:00
Jaegeuk Kim
fec1d6576c f2fs: use wait_for_stable_page to avoid contention
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>
2016-02-22 16:07:23 -08:00
Chao Yu
2304cb0c44 f2fs: export dirty_nats_ratio in sysfs
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>
2016-02-22 16:07:23 -08:00
Chao Yu
0fd785eb93 f2fs: relocate is_merged_page
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>
2016-02-22 16:07:23 -08:00
Linus Torvalds
f9a03ae123 Merge tag 'for-f2fs-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
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
  ...
2016-01-13 21:01:44 -08:00
Jaegeuk Kim
42190d2a86 f2fs: monitor the number of background checkpoint
This patch adds to show the number of background checkpoint.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-01-11 15:56:42 -08:00
Jaegeuk Kim
d0239e1bf5 f2fs: detect idle time depending on user behavior
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>
2016-01-11 15:56:37 -08:00
Jaegeuk Kim
6beceb5427 f2fs: introduce time and interval facility
This patch adds time and interval arrays to store some timing variables.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-01-11 15:36:27 -08:00
Chao Yu
68e3538510 f2fs: use atomic type for node count in extent tree
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>
2016-01-08 11:57:11 -08:00
Jaegeuk Kim
2c4db1a6f6 f2fs: clean up f2fs_balance_fs
This patch adds one parameter to clean up all the callers of f2fs_balance_fs.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-01-08 11:45:23 -08:00
Jaegeuk Kim
12719ae14e f2fs: avoid unnecessary f2fs_balance_fs calls
Only when node page is newly dirtied, it needs to check whether we need to do
f2fs_gc.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-01-08 11:45:22 -08:00
Chao Yu
e0afc4d6d0 f2fs: introduce max_file_blocks in sbi
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>
2016-01-03 21:40:04 -08:00
Jaegeuk Kim
137d09f002 f2fs: introduce zombie list for fast shrinking extent trees
This patch removes refcount, and instead, adds zombie_list to shrink directly
without radix tree traverse.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-12-31 15:39:22 -08:00
Jaegeuk Kim
c00ba55485 f2fs: monitor zombie_tree count
This patch adds an entry to show the number of zombie extent_tree.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-12-31 15:33:00 -08:00
Jaegeuk Kim
ed3d12561a f2fs: load largest extent all the time
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>
2015-12-30 10:14:20 -08:00
Yunlei He
179448bfe4 f2fs: add a max block check for get_data_block_bmap
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>
2015-12-30 10:14:17 -08:00
Chao Yu
6d5a1495ee f2fs: let user being aware of IO error
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>
2015-12-30 10:14:15 -08:00
Chao Yu
c34f42e2cb f2fs: report error of do_checkpoint
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>
2015-12-30 10:14:09 -08:00
Jaegeuk Kim
93bae099ea f2fs: record node block allocation in dnode_of_data
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>
2015-12-30 10:14:07 -08:00
Jaegeuk Kim
74fd8d9927 f2fs: speed up shrinking extent tree entries
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>
2015-12-30 10:13:00 -08:00
Jaegeuk Kim
7441ccef33 f2fs: use atomic variable for total_extent_tree
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>
2015-12-22 10:31:41 -08:00
Chao Yu
33fbd5100d f2fs: stat dirty regular/symlink inodes
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>
2015-12-17 09:53:19 -08:00
Chao Yu
343f40f0a7 f2fs: introduce new option for controlling data flush
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>
2015-12-16 09:25:48 -08:00
Chao Yu
c227f91273 f2fs: record dirty status of regular/symlink inode
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>
2015-12-16 08:58:12 -08:00
Chao Yu
e8240f656d f2fs: don't grab super block buffer header all the time
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>
2015-12-16 08:58:06 -08:00
Chao Yu
2710fd7e00 f2fs: introduce dirty list node in inode info
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>
2015-12-15 13:24:19 -08:00
Chao Yu
a49324f127 f2fs: rename {add,remove,release}_dirty_inode to {add,remove,release}_ino_entry
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>
2015-12-15 13:23:43 -08:00
Al Viro
886f56f970 f2fs: it's umode_t, not mode_t...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06 21:18:00 -05:00
Chao Yu
3519e3f992 f2fs: use sbi->blocks_per_seg to avoid unnecessary calculation
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>
2015-12-04 12:07:57 -08:00
Chao Yu
9006f2c93f f2fs: kill f2fs_drop_largest_extent
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>
2015-12-04 12:07:57 -08:00
Chao Yu
04ef4b626c f2fs: fix to enable missing ioctl interfaces in ->compat_ioctl
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>
2015-12-04 11:52:34 -08:00
Chao Yu
d323d005ac f2fs: support file defragment
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>
2015-12-04 11:52:33 -08:00
Chao Yu
787c7b8cb3 f2fs: report error of f2fs_create_root_stats
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>
2015-12-04 11:52:33 -08:00
Jaegeuk Kim
67f8cf3cee f2fs: support fiemap for inline_data
There is a FIEMAP_EXTENT_INLINE_DATA, pointed out by Marc.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-10-20 11:33:21 -07:00
Chao Yu
08b39fbd59 f2fs crypto: fix racing of accessing encrypted page among
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>
2015-10-13 09:52:34 -07:00
Chao Yu
ea1a29a0bd f2fs: export ra_nid_pages to sysfs
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>
2015-10-12 14:03:43 -07:00
Chao Yu
26879fb101 f2fs: support lower priority asynchronous readahead in ra_meta_pages
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>
2015-10-12 14:03:15 -07:00
Chao Yu
2b947003fa f2fs: don't tag REQ_META for temporary non-meta pages
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>
2015-10-12 14:01:46 -07:00
Jaegeuk Kim
a56c7c6fb3 f2fs: set GFP_NOFS for grab_cache_page
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>
2015-10-12 13:38:03 -07:00
Jaegeuk Kim
6e2c64ad7c f2fs: fix SSA updates resulting in corruption
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>
2015-10-12 13:38:02 -07:00
Jaegeuk Kim
c912a8298c f2fs: add F2FS_GOING_DOWN_METAFLUSH to test power-failure
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>
2015-10-12 13:37:54 -07:00
Jaegeuk Kim
60b99b486b f2fs: introduce a periodic checkpoint flow
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>
2015-10-09 16:20:57 -07:00
Jaegeuk Kim
6aefd93b01 f2fs: introduce background_gc=sync mount option
This patch introduce background_gc=sync enabling synchronous cleaning in
background.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-10-09 16:20:57 -07:00
Chao Yu
456b88e4d1 f2fs: introduce a new ioctl F2FS_IOC_WRITE_CHECKPOINT
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>
2015-10-09 16:20:56 -07:00
Chao Yu
d530d4d8e2 f2fs: support synchronous gc in ioctl
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>
2015-10-09 16:20:56 -07:00
Chao Yu
5b7ee37414 f2fs: use atomic64_t for extent cache hit stat
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>
2015-10-09 16:20:55 -07:00
Jaegeuk Kim
39307a8e24 f2fs: use vmalloc to handle -ENOMEM error
This patch introduces f2fs_kvmalloc to avoid -ENOMEM during mount.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-10-09 16:20:55 -07:00
Chao Yu
4abd3f5ac4 f2fs: introduce __try_update_largest_extent
This patch adds a new helper __try_update_largest_extent for cleanup.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-10-09 16:20:53 -07:00
Chao Yu
9edcdabf36 f2fs: fix overflow of size calculation
We have potential overflow issue when calculating size of object, when
we left shift index with PAGE_CACHE_SHIFT bits, if type of index has only
32-bits space in 32-bit architecture, left shifting will incur overflow,
i.e:

pgoff_t index =  0xFFFFFFFF;
loff_t size = index << PAGE_CACHE_SHIFT;
size: 0xFFFFF000

So we should cast index with 64-bits type to avoid this issue.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-10-09 16:20:50 -07:00
Chao Yu
19b2c30d3c f2fs: update extent tree in batches
This patch introduce a new helper f2fs_update_extent_tree_range which can
do extent mapping update at a specified range.

The main idea is:
1) punch all mapping info in extent node(s) which are at a specified range;
2) try to merge new extent mapping with adjacent node, or failing that,
   insert the mapping into extent tree as a new node.

In order to see the benefit, I add a function for stating time stamping
count as below:

uint64_t rdtsc(void)
{
	uint32_t lo, hi;
	__asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
	return (uint64_t)hi << 32 | lo;
}

My test environment is: ubuntu, intel i7-3770, 16G memory, 256g micron ssd.

truncation path:	update extent cache from truncate_data_blocks_range
non-truncataion path:	update extent cache from other paths
total:			all update paths

a) Removing 128MB file which has one extent node mapping whole range of
file:
1. dd if=/dev/zero of=/mnt/f2fs/128M bs=1M count=128
2. sync
3. rm /mnt/f2fs/128M

Before:
		total		count		average
truncation:	7651022		32768		233.49

Patched:
		total		count		average
truncation:	3321		33		100.64

b) fsstress:
fsstress -d /mnt/f2fs -l 5 -n 100 -p 20
Test times:		5 times.

Before:
		total		count		average
truncation:	5812480.6	20911.6		277.95
non-truncation:	7783845.6	13440.8		579.12
total:		13596326.2	34352.4		395.79

Patched:
		total		count		average
truncation:	1281283.0	3041.6		421.25
non-truncation:	7355844.4	13662.8		538.38
total:		8637127.4	16704.4		517.06

1) For the updates in truncation path:
 - we can see updating in batches leads total tsc and update count reducing
   explicitly;
 - besides, for a single batched updating, punching multiple extent nodes
   in a loop, result in executing more operations, so our average tsc
   increase intensively.
2) For the updates in non-truncation path:
 - there is a little improvement, that is because for the scenario that we
   just need to update in the head or tail of extent node, new interface
   optimize to update info in extent node directly, rather than removing
   original extent node for updating and then inserting that updated one
   into cache as new node.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-08-26 11:50:35 -07:00