linux.git/fs/f2fs/segment.c, branch v3.15

f2fs: introduce f2fs_issue_flush to avoid redundant flush issue

2014-04-07T00:50:58+00:00

Some storage devices show relatively high latencies to complete cache_flush
commands, even though their normal IO speed is prettry much high. In such
the case, it needs to merge cache_flush commands as much as possible to avoid
issuing them redundantly.
So, this patch introduces a mount option, "-o flush_merge", to mitigate such
the overhead.

If this option is enabled by user, F2FS merges the cache_flush commands and then
issues just one cache_flush on behalf of them. Once the single command is
finished, F2FS sends a completion signal to all the pending threads.

Note that, this option can be used under a workload consisting of very intensive
concurrent fsync calls, while the storage handles cache_flush commands slowly.

Signed-off-by: Jaegeuk Kim

f2fs: fix to cover io->bio with io_rwsem

2014-04-02T00:56:27+00:00

In the f2fs_wait_on_page_writeback, io->bio should be covered by io_rwsem.
Otherwise, the bio pointer can become a dangling pointer due to data races.

Signed-off-by: Jaegeuk Kim

f2fs: use list_for_each_entry{_safe} for simplyfying code

2014-04-02T00:56:27+00:00

This patch use list_for_each_entry{_safe} instead of list_for_each{_safe} for
simplfying code.

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

f2fs: avoid unnecessary bio submit when wait page writeback

2014-04-01T09:53:41+00:00

This patch introduce is_merged_page() to check whether current page is merged
in f2fs bio cache. When page is not in cache, we can avoid submitting bio cache,
resulting in having more chance to merge pages.

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

f2fs: change reclaim rate in percentage

2014-03-20T13:10:10+00:00

It is more reasonable to determine the reclaiming rate of prefree segments
according to the volume size, which is set to 5% by default.
For example, if the volume is 128GB, the prefree segments are reclaimed
when the number reaches to 6.4GB.

Signed-off-by: Jaegeuk Kim

f2fs: avoid to return incorrect errno of read_normal_summaries

2014-03-18T00:29:53+00:00

We should return error number of read_normal_summaries instead of -EINVAL when
read_normal_summaries failed.

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

f2fs: optimize restore_node_summary slightly

2014-03-10T09:45:15+00:00

Previously, we ra_sum_pages to pre-read contiguous pages as more
as possible, and if we fail to alloc more pages, an ENOMEM error
will be reported upstream, even though we have alloced some pages
yet. In fact, we can use the available pages to do the job partly,
and continue the rest in the following circle. Only reporting ENOMEM
upstream if we really can not alloc any available page.

And another fix is ignoring dealing with the following pages if an
EIO occurs when reading page from page_list.

Signed-off-by: Gu Zheng 
Reviewed-by: Chao Yu 
[Jaegeuk Kim: modify the flow for better neat code]
Signed-off-by: Jaegeuk Kim

f2fs: remove the unused ctor argument of f2fs_kmem_cache_create()

2014-03-10T09:45:14+00:00

Signed-off-by: Gu Zheng 
Signed-off-by: Jaegeuk Kim

f2fs: introduce ra_meta_pages to readahead CP/NAT/SIT pages

2014-02-17T05:58:53+00:00

This patch help us to cleanup the readahead code by merging ra_{sit,nat}_pages
function into ra_meta_pages.
Additionally the new function is used to readahead cp block in
recover_orphan_inodes.

Change log from v1:
 o fix a deadloop bug pointed by Jaegeuk Kim.

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

f2fs: clean up with a macro

2014-02-17T05:58:52+00:00

This patch adds GET_BLKOFF_FROM_SEG0 to clean up some codes.

Signed-off-by: Jaegeuk Kim