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>
This patch enhances the checkpoint routine to cope with IO errors.
Basically f2fs detects IO errors from end_io_write, and the errors are able to
be occurred during one of data, node, and meta page writes.
In the previous code, when an IO error is occurred during writes, f2fs sets a
flag, CP_ERROR_FLAG, in the raw ckeckpoint buffer which will be written to disk.
Afterwards, write_checkpoint() will check the flag and remount f2fs as a
read-only (ro) mode.
However, even once f2fs is remounted as a ro mode, dirty checkpoint pages are
freely able to be written to disk by flusher or kswapd in background.
In such a case, after cold reboot, f2fs would restore the checkpoint data having
CP_ERROR_FLAG, resulting in disabling write_checkpoint and remounting f2fs as
a ro mode again.
Therefore, let's prevent any checkpoint page (meta) writes once an IO error is
occurred, and remount f2fs as a ro mode right away at that moment.
Reported-by: Oliver Winker <oliver@oli1170.net>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
I'd like to revisit the f2fs_gc flow and rewrite as follows.
1. In practical, the nGC parameter of f2fs_gc is meaningless. So, let's
remove it.
2. Background GC marks victim blocks as dirty one at a time.
3. Foreground GC should do cleaning job until acquiring enough free
sections. Afterwards, it needs to do checkpoint.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Since, the memory for the object of dirty_seglist_info is allocated
using kzalloc - which returns zeroed out memory. So, there is no need
to initialize the nr_dirty values with zeroes.
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>
Practically, has_not_enough_free_secs() should calculate with the numbers of
current node and directory data blocks together.
Actually the equation was implemented in need_to_flush().
So, this patch removes need_flush() and moves the equation into
has_not_enough_free_secs().
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This patch resolves a build warning reported by kbuild test robot.
"
fs/f2fs/segment.c: In function '__get_segment_type':
fs/f2fs/segment.c:806:1: warning: control reaches end of non-void
function [-Wreturn-type]
"
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
m68k allmodconfig:
fs/f2fs/data.c: In function ‘read_end_io’:
fs/f2fs/data.c:311: error: implicit declaration of function ‘prefetchw’
fs/f2fs/segment.c: In function ‘f2fs_end_io_write’:
fs/f2fs/segment.c:628: error: implicit declaration of function ‘prefetchw’
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
We should guarantee not to do *scheduling while atomic*.
I found, in atomic f2fs_end_io_write(), there is a set_page_dirty() call
to deal with IO errors.
But, set_page_dirty() calls:
-> f2fs_set_data_page_dirty()
-> set_dirty_dir_page()
-> cond_resched() which results in scheduling.
In order to avoid this, I'd like to remove simply set_page_dirty(),
since the page is already marked as ERROR and f2fs will be operated
as the read-only mode as well.
So, there is no recovery issue with this.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Do cleanup more for better code readability.
- Change the parameter set of f2fs_bio_alloc()
This function should allocate a bio only since it is not something like
f2fs_bio_init(). Instead, the caller should initialize the allocated bio.
- Introduce SECTOR_FROM_BLOCK
This macro translates a block address to its sector address.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Since, GFP_NOFS(__GFP_WAIT) is used for allocation requests of bio in f2fs.
So, there is no chance of returning NULL from the BIO allocation.
Making the bio allocation routine for f2fs simpler.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
No need to initialize "struct f2fs_gc_kthread *gc_th = NULL",
as gc_th = NULL, will be taken care by the return values of kmalloc().
And fix codes in other places.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
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>
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>
This adds specific functions not only to manage dirty/free segments, SIT pages,
a cache for SIT entries, and summary entries, but also to allocate free blocks
and write three types of pages: data, node, and meta.
- F2FS maintains three types of bitmaps in memory, which indicate free, prefree,
and dirty segments respectively.
- The key information of an SIT entry consists of a segment number, the number
of valid blocks in the segment, a bitmap to identify there-in valid or invalid
blocks.
- An SIT page is composed of a certain range of SIT entries, which is maintained
by the address space of meta_inode.
- To cache SIT entries, a simple array is used. The index for the array is the
segment number.
- A summary entry for data contains the parent node information. A summary entry
for node contains its node offset from the inode.
- F2FS manages information about six active logs and those summary entries in
memory. Whenever one of them is changed, its summary entries are flushed to
its SIT page maintained by the address space of meta_inode.
- This patch adds a default block allocation function which supports heap-based
allocation policy.
- This patch adds core functions to write data, node, and meta pages. Since LFS
basically produces a series of sequential writes, F2FS merges sequential bios
with a single one as much as possible to reduce the IO scheduling overhead.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
