linux.git/fs/f2fs/node.h, branch v4.9

f2fs: introduce cp_lock to protect updating of ckpt_flags

2016-10-01T00:34:20+00:00

This patch introduces spinlock to protect updating process of ckpt_flags
field in struct f2fs_checkpoint, it avoids incorrectly updating in race
condition.

Signed-off-by: Chao Yu 
[Jaegeuk Kim: add __is_set_ckpt_flags likewise __set_ckpt_flags]
Signed-off-by: Jaegeuk Kim

f2fs: use crc and cp version to determine roll-forward recovery

2016-09-30T17:05:46+00:00

Previously, we used cp_version only to detect recoverable dnodes.
In order to avoid same garbage cp_version, we needed to truncate the next
dnode during checkpoint, resulting in additional discard or data write.
If we can distinguish this by using crc in addition to cp_version, we can
remove this overhead.

There is backward compatibility concern where it changes node_footer layout.
So, this patch introduces a new checkpoint flag, CP_CRC_RECOVERY_FLAG, to
detect new layout. New layout will be activated only when this flag is set.

Signed-off-by: Jaegeuk Kim

f2fs: produce more nids and reduce readahead nats

2016-07-06T17:44:08+00:00

The readahead nat pages are more likely to be reclaimed quickly, so it'd better
to gather more free nids in advance.

And, let's keep some free nids as much as possible.

Signed-off-by: Jaegeuk Kim

f2fs: control not to exceed # of cached nat entries

2016-06-07T17:18:08+00:00

This is to avoid cache entry management overhead including radix tree.

Signed-off-by: Jaegeuk Kim

f2fs: fix wrong percentage

2016-06-07T16:45:41+00:00

This should be 1%, 10MB / 1GB.

Signed-off-by: Jaegeuk Kim

f2fs: use wait_for_stable_page to avoid contention

2016-02-23T00:07:23+00:00

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

f2fs: avoid multiple node page writes due to inline_data

2016-02-23T00:07:23+00:00

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 
Signed-off-by: Jaegeuk Kim

f2fs: export dirty_nats_ratio in sysfs

2016-02-23T00:07:23+00:00

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 
Signed-off-by: Jaegeuk Kim

f2fs: flush dirty nat entries when exceeding threshold

2016-02-23T00:07:23+00:00

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 
Signed-off-by: Jaegeuk Kim

f2fs: avoid unnecessary f2fs_balance_fs calls

2016-01-08T19:45:22+00:00

Only when node page is newly dirtied, it needs to check whether we need to do
f2fs_gc.

Signed-off-by: Jaegeuk Kim