Now we use inmemory pages for atomic write only and provide abort procedure,
we don't need to truncate them explicitly.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The ckpt_valid_map and cur_valid_map are synced by seg_info_to_raw_sit.

In the case of small discards, the candidates are selected before sync,
while fitrim selects candidates after sync.

So, for small discards, we need to add candidates only just being obsoleted.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds two new ioctls to release inmemory pages grabbed by atomic
writes.
 o f2fs_ioc_abort_volatile_write
  - If transaction was failed, all the grabbed pages and data should be written.
 o f2fs_ioc_release_volatile_write
  - This is to enhance the performance of PERSIST mode in sqlite.

In order to avoid huge memory consumption which causes OOM, this patch changes
volatile writes to use normal dirty pages, instead blocked flushing to the disk
as long as system does not suffer from memory pressure.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We don't need to call lock_op and lock_page at the aborting path.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If there is not enough available memory, we need to trigger f2fs_sync_fs.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds counting # of inmemory pages in the page cache.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The inmemory pages should be handled by invalidate_page since it needs to be
released int the truncation path.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch revists retrial paths in f2fs.
The basic idea is to use cond_resched instead of retrying from the very early
stage.
Suggested-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In f2fs_evict_inode,
 commit_inmemory_pages
   f2fs_gc
     f2fs_iget
       iget_locked
         -> wait for inode free

Here, if the inode is same as the one to be evicted, f2fs should wait forever.
Actually, we should not call f2fs_balance_fs during f2fs_evict_inode to avoid
this.

But, the commit_inmem_pages calls f2fs_balance_fs by default, even if
f2fs_evict_inode wants to free inmemory pages only.

Hence, this patch adds to trigger f2fs_balance_fs only when there is something
to write.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

It used nat_entry_set when create slab for sit_entry_set.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds to control the memory footprint used by ino entries.
This will conduct best effort, not strictly.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The roll-forward mechanism should be activated when the number of active
logs is not 2.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If there is a chance to make a huge sized discard command, we don't need
to split it out, since each blkdev_issue_discard should wait one at a
time.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We should not discard any data protected by the previous checkpoint all
the time.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

During the write_checkpoint, we should avoid f2fs_gc trigger to avoid any
filesystem consistency.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Rename f2fs_set/clear_bit to f2fs_test_and_set/clear_bit, which mean
set/clear bit and return the old value, for better readability.
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If user specifies too low end sector for trimming, f2fs_trim_fs() will
use uninitialized value as a number of trimmed blocks and returns it to
userspace. Initialize number of trimmed blocks early to avoid the
problem.

Coverity-id: 1248809
CC: stable@vger.kernel.org
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch removes build warning.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If user truncates file's data, we should truncate inmemory pages too.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch let inmemory pages be clean all the time.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

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: NJaegeuk Kim <jaegeuk@kernel.org>

This patch cleans up the existing and new macros for readability.

Rule is like this.

         ,-----------------------------------------> MAX_BLKADDR -,
         |  ,------------- TOTAL_BLKS ----------------------------,
         |  |                                                     |
         |  ,- seg0_blkaddr   ,----- sit/nat/ssa/main blkaddress  |
block    |  | (SEG0_BLKADDR)  | | | |   (e.g., MAIN_BLKADDR)      |
address  0..x................ a b c d .............................
            |                                                     |
global seg# 0...................... m .............................
            |                       |                             |
            |                       `------- MAIN_SEGS -----------'
            `-------------- TOTAL_SEGS ---------------------------'
                                    |                             |
 seg#                               0..........xx..................

= Note =
 o GET_SEGNO_FROM_SEG0 : blk address -> global segno
 o GET_SEGNO           : blk address -> segno
 o START_BLOCK         : segno -> starting block address
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces FITRIM in f2fs_ioctl.
In this case, f2fs will issue small discards and prefree discards as many as
possible for the given area.
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch changes the ipu_policy setting to use any combination of orthogonal policies.
Signed-off-by: NChangman Lee <cm224.lee@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Block size in f2fs is 4096 bytes, so theoretically, f2fs can support 4096 bytes
sector device at maximum. But now f2fs only support 512 bytes size sector, so
block device such as zRAM which uses page cache as its block storage space will
not be mounted successfully as mismatch between sector size of zRAM and sector
size of f2fs supported.

In this patch we support large sector size in f2fs, so block device with sector
size of 512/1024/2048/4096 bytes can be supported in f2fs.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch cleans up a simple macro.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If user wrote F2FS_IPU_FSYNC:4 in /sys/fs/f2fs/ipu_policy, f2fs_sync_file
only starts to try in-place-updates.
And, if the number of dirty pages is over /sys/fs/f2fs/min_fsync_blocks, it
keeps out-of-order manner. Otherwise, it triggers in-place-updates.

This may be used by storage showing very high random write performance.

For example, it can be used when,

Seq. writes (Data) + wait + Seq. writes (Node)

is pretty much slower than,

Rand. writes (Data)
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

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: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

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

sit_i in macro SIT_BLOCK_OFFSET/START_SEGNO is not used, remove it.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds to handle corner buggy cases for fsck.f2fs.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch replaces BUG cases with f2fs_bug_on to remain fsck.f2fs information.
And it implements some void functions to initiate fsck.f2fs too.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If any f2fs_bug_on is triggered, fsck.f2fs is needed.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds three inline functions to clean up dirty casting codes.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

I think we need to let the dirty node pages remain in the page cache instead
of rewriting them in their places.
So, after done with successful recovery, write_checkpoint will flush all of them
through the normal write path.
Through this, we can avoid potential error cases in terms of block allocation.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Fix typo and some grammatical errors.

The words "filesystem" and "readahead" are being used without the space treewide.
Signed-off-by: NPark Ju Hyung <qkrwngud825@gmail.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch uses for_each_set_bit to simplify some codes in f2fs.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

There are redundant lines in allocate_data_block.

In this function, we call refresh_sit_entry with old seg and old curseg.
After that, we call locate_dirty_segment with old curseg.

But, the new address is always allocated from old curseg and
we call locate_dirty_segment with old curseg in refresh_sit_entry.
So, we do not need to call locate_dirty_segment with old curseg again.

We've discussed like below:

Jaegeuk said:
 "When considering SSR, we need to take care of the following scenario.
  - old segno : X
  - new address : Z
  - old curseg : Y
  This means, a new block is supposed to be written to Z from X.
  And Z is newly allocated in the same path from Y.

  In that case, we should trigger locate_dirty_segment for Y, since
  it was a current_segment and can be dirty owing to SSR.
  But that was not included in the dirty list."

Changman said:
 "We already choosed old curseg(Y) and then we allocate new address(Z) from old
  curseg(Y). After that we call refresh_sit_entry(old address, new address).
  In the funcation, we call locate_dirty_segment with old seg and old curseg.
  So calling locate_dirty_segment after refresh_sit_entry again is redundant."

Jaegeuk said:
 "Right. The new address is always allocated from old_curseg."
Reviewed-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NDongho Sim <dh.sim@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds a tracepoint for f2fs_issue_flush.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>