Commit Graph

127 Commits

Author SHA1 Message Date
Jaegeuk Kim c3850aa1cb f2fs: fix return value of releasepage for node and data
If the return value of releasepage is equal to zero, the page cannot be reclaimed.
Instead, we should return 1 in order to reclaim clean pages.

Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-03-20 18:30:13 +09:00
Jaegeuk Kim 48cb76c7be f2fs: scan next nat page to reuse free nids in there
When we build new free nids, let's scan the just next NAT page instead of
skipping a couple of previously scanned pages in order to reuse free nids in
there.
Otherwise, we can use too much wide range of nids even though several nids were
deallocated, and also their node pages can be cached in the node_inode's address
space.
This means that we can retain lots of clean pages in the main memory, which
induces mm's reclaiming overhead.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-03-20 18:30:12 +09:00
Jaegeuk Kim 08d8058be6 f2fs: should check the node page was truncated first
Currently, f2fs doesn't reclaim any node pages.
However, if we found that a node page was truncated by checking its block
address with zero during f2fs_write_node_page, we should not skip that node
page and return zero to reclaim it.

Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-03-20 18:30:12 +09:00
Jaegeuk Kim 393ff91f57 f2fs: reduce unncessary locking pages during read
This patch reduces redundant locking and unlocking pages during read operations.
In f2fs_readpage, let's use wait_on_page_locked() instead of lock_page.
And then, when we need to modify any data finally, let's lock the page so that
we can avoid lock contention.

[readpage rule]
- The f2fs_readpage returns unlocked page, or released page too in error cases.
- Its caller should handle read error, -EIO, after locking the page, which
  indicates read completion.
- Its caller should check PageUptodate after grab_cache_page.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-03-20 18:30:06 +09:00
Namjae Jeon 25c0a6e529 f2fs: avoid extra ++ while returning from get_node_path
In all the breaking conditions in get_node_path, 'n' is used to
track index in offset[] array, but while breaking out also, in all
paths n++ is done.
So, remove the ++ from breaking paths. Also, avoid
reset of 'level=0' in first case.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-03-18 21:00:36 +09:00
Namjae Jeon 3aa770a9c9 f2fs: optimize and change return path in lookup_free_nid_list
Optimize and change return path in lookup_free_nid_list

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-03-18 21:00:35 +09:00
Namjae Jeon e0f56cb44b f2fs: optimize get node page readahead part
We can remove the call to find_get_page to get a page from the cache
and check for up-to-date, instead we can make use of grab_cache_page
part itself to fetch the page from the cache.
So, removing the call and moving the PageUptodate at proper place, also
taken care of moving the lock_page condition in the page_hit part.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-03-18 21:00:34 +09:00
Changman Lee 52c2db3f95 f2fs: check the level before calling get_nid function
The caller of get_nid should be careful not to put lower value than
NODE_DIR1_BLOCK in case of level is zero.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-03-18 21:00:34 +09:00
Jaegeuk Kim 266e97a81c f2fs: introduce readahead mode of node pages
Previously, f2fs reads several node pages ahead when get_dnode_of_data is called
with RDONLY_NODE flag.
And, this flag is set by the following functions.
- get_data_block_ro
- get_lock_data_page
- do_write_data_page
- truncate_blocks
- truncate_hole

However, this readahead mechanism is initially introduced for the use of
get_data_block_ro to enhance the sequential read performance.

So, let's clarify all the cases with the additional modes as follows.

enum {
	ALLOC_NODE,	/* allocate a new node page if needed */
	LOOKUP_NODE,	/* look up a node without readahead */
	LOOKUP_NODE_RA,	/*
			 * look up a node with readahead called
			 * by get_datablock_ro.
			 */
}

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2013-03-18 21:00:33 +09:00
Jaegeuk Kim 66d36a2944 f2fs: read with READ_SYNC when getting dnode page
The get_node_page_ra tries to:
1. grab or read a target node page for the given nid,
2. then, call ra_node_page to read other adjacent node pages in advance.

So, when we try to read a target node page by #1, we should submit bio with
READ_SYNC instead of READA.
And, in #2, READA should be used.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2013-03-18 21:00:33 +09:00
Jaegeuk Kim 12faafe454 f2fs: fix to unlock node page when it was truncated
If the node page was truncated, its block address became zero.
This means that we don't need to write the node page, but have to unlock
NODE_WRITE, decrease the number of dirty node pages, and then unlock_page
before returning the f2fs_write_node_page with zero.

Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-03-18 21:00:09 +09:00
Jaegeuk Kim 7dd690c820 f2fs: avoid build warning
This patch removes the following build warning:
fs/f2fs/node.c: warning: 'nofs' may be used uninitialized in this function
[-Wuninitialized]:  => 738:8

Note that this is a false alarm.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:28:55 +09:00
Jaegeuk Kim 90b2fc64f0 Merge branch 'f2fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into dev
Pull f2fs cleanup patches from Al Viro:

f2fs: get rid of fake on-stack dentries
f2fs: switch init_inode_metadata() to passing parent and name separately
f2fs: switch new_inode_page() from dentry to qstr
f2fs: init_dent_inode() should take qstr

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

Conflicts:
	fs/f2fs/recovery.c
2013-02-12 07:17:20 +09:00
Jaegeuk Kim 437275272f f2fs: clarify and enhance the f2fs_gc flow
This patch makes clearer the ambiguous f2fs_gc flow as follows.

1. Remove intermediate checkpoint condition during f2fs_gc
 (i.e., should_do_checkpoint() and GC_BLOCKED)

2. Remove unnecessary return values of f2fs_gc because of #1.
 (i.e., GC_NODE, GC_OK, etc)

3. Simplify write_checkpoint() because of #2.

4. Clarify the main f2fs_gc flow.
 o monitor how many freed sections during one iteration of do_garbage_collect().
 o do GC more without checkpoints if we can't get enough free sections.
 o do checkpoint once we've got enough free sections through forground GCs.

5. Adopt thread-logging (Slack-Space-Recycle) scheme more aggressively on data
  log types. See. get_ssr_segement()

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:02 +09:00
Jaegeuk Kim 369a708c2a f2fs: remove the use of page_cache_release
Let's remove the use of page_cache_release() in f2fs, and instead, use
f2fs_put_page(page, 0) which is exactly same but for code readability.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:01 +09:00
Namjae Jeon a2b52a598a f2fs: reorganize code for ra_node_page
We can remove unneeded label unlock_out, avoid unnecessary jump
and reorganize the returning conditions in this function.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12 07:15:01 +09:00
Al Viro c004363dd6 f2fs: switch new_inode_page() from dentry to qstr
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-08 02:55:03 -05:00
Al Viro 53dc9a6776 f2fs: init_dent_inode() should take qstr
for one thing, it doesn't (and shouldn't) use anything else from dentry;
for another, on some call chains the dentry is fake and should
be eliminated completely.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-08 02:55:03 -05:00
Jaegeuk Kim a7fdffbd3e f2fs: avoid issuing small bios due to several dirty node pages
If some small bios of dirty node pages are supposed to be issued during the
sequential data writes, there-in well-produced consecutive data bios are able
to be split by the small node bios, resulting in performance degradation.
So, let's collect a number of dirty node pages until reaching a threshold.
And, by default, I set the threshold as 2MB, a segment size.

This improves sequential write performance on i5, 512GB SSD (830 w/ SATA2) as
follows.
Before: 231 MB/s -> After: 255 MB/s

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2013-01-22 10:48:59 +09:00
Namjae Jeon 6e6093a8f1 f2fs: add __init to functions in init_f2fs_fs
Add __init to functions in init_f2fs_fs for code consistency.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-22 10:48:38 +09:00
Jaegeuk Kim 2b50638dec f2fs: clean up unused variables and return values
This patch cleans up a couple of unnecessary codes related to unused variables
and return values.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-28 11:27:52 +09:00
Jaegeuk Kim 71e9fec548 f2fs: invalidate the node page if allocation is failed
The new_node_page() is processed as the following procedure.

1. A new node page is allocated.
2. Set PageUptodate with proper footer information.
3. Check if there is a free space for allocation
 4.a. If there is no space, f2fs returns with -ENOSPC.
 4.b. Otherwise, go next.

In the case of step #4.a, f2fs remains a wrong node page in the page cache
with the uptodate flag.

Also, even though a new node page is allocated successfully, an error can be
occurred afterwards due to allocation failure of the other data structures.
In such a case, remove_inode_page() would be triggered, so that we have to
clear uptodate flag in truncate_node() too.

So, we should remove the uptodate flag, if allocation is failed.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-28 11:24:09 +09:00
Jaegeuk Kim 398b1ac5a5 f2fs: fix handling errors got by f2fs_write_inode
Ruslan reported that f2fs hangs with an infinite loop in f2fs_sync_file():

	while (sync_node_pages(sbi, inode->i_ino, &wbc) == 0)
		f2fs_write_inode(inode, NULL);

The reason was revealed that the cold flag is not set even thought this inode is
a normal file. Therefore, sync_node_pages() skips to write node blocks since it
only writes cold node blocks.

The cold flag is stored to the node_footer in node block, and whenever a new
node page is allocated, it is set according to its file type, file or directory.

But, after sudden-power-off, when recovering the inode page, f2fs doesn't recover
its cold flag.

So, let's assign the cold flag in more right places.

One more thing:
If f2fs_write_inode() returns an error due to whatever situations, there would
be no dirty node pages so that sync_node_pages() returns zero.
(i.e., zero means nothing was written.)

Reported-by: Ruslan N. Marchenko <me@ruff.mobi>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-26 10:39:52 +09:00
Namjae Jeon be4124f872 f2fs: fix the compiler warning for uninitialized use of variable
When CONFIG_CC_OPTIMIZE_FOR_SIZE is enabled in the kernel, -Os optimisation
flag is passed to gcc for compilation, and somehow while trying to optimize
the code, compiler is might not able to see the initialisation of variable
ne struct variable inside the get_node_info() function and results into
following warning:

fs/f2fs/node.c: In function 'get_node_info':
fs/f2fs/node.c:175:3: warning: 'ne.block_addr' may be used uninitialized in
this function [-Wuninitialized]
fs/f2fs/node.c:265:24: note: 'ne.block_addr' was declared here
fs/f2fs/node.c:176:3: warning: 'ne.ino' may be used uninitialized in this
function [-Wuninitialized]
fs/f2fs/node.c:265:24: note: 'ne.ino' was declared here
fs/f2fs/node.c:177:3: warning: 'ne.version' may be used uninitialized in
this function [-Wuninitialized]
fs/f2fs/node.c:265:24: note: 'ne.version' was declared here

Hence, lets initialise the ne struct variable to zero, which will remove
this warning and also doing this does not seems to making any impact on the
code behavior.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com>
2012-12-11 13:43:43 +09:00
Jaegeuk Kim 0a8165d7c2 f2fs: adjust kernel coding style
As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment
blocks. Instead, just use "/*".

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11 13:43:42 +09:00
Jaegeuk Kim 25ca923b2a f2fs: fix endian conversion bugs reported by sparse
This patch should resolve the bugs reported by the sparse tool.
Initial reports were written by "kbuild test robot" managed by fengguang.wu.

In my local machines, I've tested also by running:
> make C=2 CF="-D__CHECK_ENDIAN__"

Accordingly, I've found lots of warnings and bugs related to the endian
conversion. And I've fixed all at this moment.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11 13:43:42 +09:00
Jaegeuk Kim e05df3b115 f2fs: add node operations
This adds specific functions to manage NAT pages, a cache for NAT entries, free
nids, direct/indirect node blocks for indexing data, and address space for node
pages.

- The key information of an NAT entry consists of a node id and a block address.

- An NAT page is composed of block addresses covered by a certain range of NAT
  entries, which is maintained by the address space of meta_inode.

- A radix tree structure is used to cache NAT entries. The index for the tree
  is a node id.

- When there is no free nid, F2FS should scan NAT entries to find new one. In
  order to avoid scanning frequently, F2FS manages a list containing a number of
  free nids in memory. Only when free nids in the list are exhausted, scanning
  process, build_free_nids(), is triggered.

- F2FS has direct and indirect node blocks for indexing data. This patch adds
  fuctions related to the node block management such as getting, allocating, and
  truncating node blocks to index data.

- In order to cache node blocks in memory, F2FS has a node_inode with an address
  space for node pages. This patch also adds the address space operations for
  node_inode.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11 13:43:40 +09:00