linux.git/fs/f2fs/node.h, branch v4.6

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

f2fs: use sbi->blocks_per_seg to avoid unnecessary calculation

2015-12-04T20:07:57+00:00

Use sbi->blocks_per_seg directly to avoid unnecessary calculation when using
1 << sbi->log_blocks_per_seg.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: export ra_nid_pages to sysfs

2015-10-12T21:03:43+00:00

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 
Signed-off-by: Jaegeuk Kim

Revert "f2fs: do not skip dentry block writes"

2015-10-12T20:38:02+00:00

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.

f2fs: do not skip dentry block writes

2015-10-09T23:20:54+00:00

Previously, we skip dentry block writes when wbc is SYNC_NONE with no memory
pressure and the number of dirty pages is pretty small.

But, we didn't skip for normal data writes, which gives us not much big impact
on overall performance.
Moreover, by skipping some data writes, kworker falls into infinite loop to try
to write blocks, when many dir inodes have only one dentry block.

So, this patch removes skipping data writes.

Signed-off-by: Jaegeuk Kim

f2fs: move existing definitions into f2fs.h

2015-05-28T22:41:27+00:00

This patch moves some inode-related definitions from node.h to f2fs.h to
add new features.

Signed-off-by: Jaegeuk Kim