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  1. 04 Nov, 2014 13 commits
  3. 07 Oct, 2014 2 commits
    • Jaegeuk Kim's avatar
      f2fs: support volatile operations for transient data · 02a1335f
      Jaegeuk Kim authored 
      
This patch adds support for volatile writes which keep data pages in memory
until f2fs_evict_inode is called by iput.

For instance, we can use this feature for the sqlite database as follows.
While supporting atomic writes for main database file, we can keep its journal
data temporarily in the page cache by the following sequence.

1. open
 -> ioctl(F2FS_IOC_START_VOLATILE_WRITE);
2. writes
 : keep all the data in the page cache.
3. flush to the database file with atomic writes
  a. ioctl(F2FS_IOC_START_ATOMIC_WRITE);
  b. writes
  c. ioctl(F2FS_IOC_COMMIT_ATOMIC_WRITE);
4. close
 -> drop the cached data
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      02a1335f
    • Jaegeuk Kim's avatar
      f2fs: support atomic writes · 88b88a66
      Jaegeuk Kim authored 
      
This patch introduces a very limited functionality for atomic write support.
In order to support atomic write, this patch adds two ioctls:
 o F2FS_IOC_START_ATOMIC_WRITE
 o F2FS_IOC_COMMIT_ATOMIC_WRITE

The database engine should be aware of the following sequence.
1. open
 -> ioctl(F2FS_IOC_START_ATOMIC_WRITE);
2. writes
  : all the written data will be treated as atomic pages.
3. commit
 -> ioctl(F2FS_IOC_COMMIT_ATOMIC_WRITE);
  : this flushes all the data blocks to the disk, which will be shown all or
  nothing by f2fs recovery procedure.
4. repeat to #2.

The IO pattens should be:

  ,- START_ATOMIC_WRITE                  ,- COMMIT_ATOMIC_WRITE
 CP | D D D D D D | FSYNC | D D D D | FSYNC ...
                      `- COMMIT_ATOMIC_WRITE
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      88b88a66
  5. 30 Sep, 2014 4 commits
  7. 23 Sep, 2014 3 commits
    • Jaegeuk Kim's avatar
      f2fs: remove redundant operation during roll-forward recovery · c52e1b10
      Jaegeuk Kim authored 
      
If same data is updated multiple times, we don't need to redo whole the
operations.
Let's just update the lastest one.
Reviewed-by: default avatarChao Yu <chao2.yu@samsung.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      c52e1b10
    • Jaegeuk Kim's avatar
      f2fs: fix conditions to remain recovery information in f2fs_sync_file · 88bd02c9
      Jaegeuk Kim authored 
      
This patch revisited whole the recovery information during the f2fs_sync_file.

In this patch, there are three information to make a decision.

a) IS_CHECKPOINTED,	/* is it checkpointed before? */
b) HAS_FSYNCED_INODE,	/* is the inode fsynced before? */
c) HAS_LAST_FSYNC,	/* has the latest node fsync mark? */

And, the scenarios for our rule are based on:

[Term] F: fsync_mark, D: dentry_mark

1. inode(x) | CP | inode(x) | dnode(F)
2. inode(x) | CP | inode(F) | dnode(F)
3. inode(x) | CP | dnode(F) | inode(x) | inode(F)
4. inode(x) | CP | dnode(F) | inode(F)
5. CP | inode(x) | dnode(F) | inode(DF)
6. CP | inode(DF) | dnode(F)
7. CP | dnode(F) | inode(DF)
8. CP | dnode(F) | inode(x) | inode(DF)

For example, #3, the three conditions should be changed as follows.

   inode(x) | CP | dnode(F) | inode(x) | inode(F)
a)    x       o      o          o          o
b)    x       x      x          x          o
c)    x       o      o          x          o

If f2fs_sync_file stops   ------^,
 it should write inode(F)    --------------^

So, the need_inode_block_update should return true, since
 c) get_nat_flag(e, HAS_LAST_FSYNC), is false.

For example, #8,
      CP | alloc | dnode(F) | inode(x) | inode(DF)
a)    o      x        x          x          x
b)    x               x          x          o
c)    o               o          x          o

If f2fs_sync_file stops   -------^,
 it should write inode(DF)    --------------^

Note that, the roll-forward policy should follow this rule, which means,
if there are any missing blocks, we doesn't need to recover that inode.
Signed-off-by: default avatarHuang Ying <ying.huang@intel.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      88bd02c9
    • Jaegeuk Kim's avatar
      f2fs: use meta_inode cache to improve roll-forward speed · 4c521f49
      Jaegeuk Kim authored 
      
Previously, all the dnode pages should be read during the roll-forward recovery.
Even worsely, whole the chain was traversed twice.
This patch removes that redundant and costly read operations by using page cache
of meta_inode and readahead function as well.
Reviewed-by: default avatarChao Yu <chao2.yu@samsung.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      4c521f49
  9. 16 Sep, 2014 2 commits
  11. 09 Sep, 2014 4 commits
    • Gu Zheng's avatar
      f2fs: use lock-less list(llist) to simplify the flush cmd management · 721bd4d5
      Gu Zheng authored 
      
We use flush cmd control to collect many flush cmds, and flush them
together. In this case, we use two list to manage the flush cmds
(collect and dispatch), and one spin lock is used to protect this.
In fact, the lock-less list(llist) is very suitable to this case,
and we use simplify this routine.

-
v2:
-use llist_for_each_entry_safe to fix possible use-after-free issue.
-remove the unused field from struct flush_cmd.
Thanks for Yu's suggestion.
-
Signed-off-by: default avatarGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      721bd4d5
    • Chao Yu's avatar
      f2fs: refactor flush_sit_entries codes for reducing SIT writes · 184a5cd2
      Chao Yu authored 
      In commit aec71382

 ("f2fs: refactor flush_nat_entries codes for reducing NAT
writes"), we descripte the issue as below:

"Although building NAT journal in cursum reduce the read/write work for NAT
block, but previous design leave us lower performance when write checkpoint
frequently for these cases:
1. if journal in cursum has already full, it's a bit of waste that we flush all
   nat entries to page for persistence, but not to cache any entries.
2. if journal in cursum is not full, we fill nat entries to journal util
   journal is full, then flush the left dirty entries to disk without merge
   journaled entries, so these journaled entries may be flushed to disk at next
   checkpoint but lost chance to flushed last time."

Actually, we have the same problem in using SIT journal area.

In this patch, firstly we will update sit journal with dirty entries as many as
possible. Secondly if there is no space in sit journal, we will remove all
entries in journal and walk through the whole dirty entry bitmap of sit,
accounting dirty sit entries located in same SIT block to sit entry set. All
entry sets are linked to list sit_entry_set in sm_info, sorted ascending order
by count of entries in set. Later we flush entries in set which have fewest
entries into journal as many as we can, and then flush dense set with merged
entries to disk.

In this way we can use sit journal area more effectively, also we will reduce
SIT update, result in gaining in performance and saving lifetime of flash
device.

In my testing environment, it shows this patch can help to reduce SIT block
update obviously.

virtual machine + hard disk:
fsstress -p 20 -n 400 -l 5
		sit page num	cp count	sit pages/cp
based		2006.50		1349.75		1.486
patched		1566.25		1463.25		1.070

Our latency of merging op is small when handling a great number of dirty SIT
entries in flush_sit_entries:
latency(ns)	dirty sit count
36038		2151
49168		2123
37174		2232
Signed-off-by: default avatarChao Yu <chao2.yu@samsung.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      184a5cd2
    • Jaegeuk Kim's avatar
      f2fs: need fsck.f2fs when f2fs_bug_on is triggered · 9850cf4a
      Jaegeuk Kim authored 
      
If any f2fs_bug_on is triggered, fsck.f2fs is needed.
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      9850cf4a
    • Jaegeuk Kim's avatar
      f2fs: retain inconsistency information to initiate fsck.f2fs · 2ae4c673
      Jaegeuk Kim authored 
      
This patch adds sbi->need_fsck to conduct fsck.f2fs later.
This flag can only be removed by fsck.f2fs.
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
      2ae4c673
  13. 04 Sep, 2014 1 commit
  15. 21 Aug, 2014 5 commits
  17. 19 Aug, 2014 4 commits
  19. 02 Aug, 2014 1 commit
  21. 31 Jul, 2014 1 commit
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