The f2fs has three bio types, NODE, DATA, and META, and manages some data
structures per each bio types.
The codes are a little bit messy, thus, this patch introduces a bio array
which groups individual data structures as follows.
struct f2fs_bio_info {
struct bio *bio; /* bios to merge */
sector_t last_block_in_bio; /* last block number */
struct mutex io_mutex; /* mutex for bio */
};
struct f2fs_sb_info {
...
struct f2fs_bio_info write_io[NR_PAGE_TYPE]; /* for write bios */
...
};
The code changes from this new data structure are trivial.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
The f2fs manages an extent cache to search a number of consecutive data blocks
very quickly.
However it conducts unnecessary cache operations if the file is highly
fragmented with no valid extent cache.
In such the case, we don't need to handle the extent cache, but just can disable
the cache facility.
Nevertheless, this patch gives one more chance to enable the extent cache.
For example,
1. create a file
2. write data sequentially which produces a large valid extent cache
3. update some data, resulting in a fragmented extent
4. if the fragmented extent is too small, then drop extent cache
5. close the file
6. open the file again
7. give another chance to make a new extent cache
8. write data sequentially again which creates another big extent cache.
...
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This patch removes an unnecessary semaphore (i.e., sbi->bio_sem).
There is no reason to use the semaphore when f2fs submits read and write IOs.
Instead, let's use a write mutex and cover the sbi->bio[] by the lock.
Change log from v1:
o split write_mutex suggested by Chao Yu
Chao described,
"All DATA/NODE/META bio buffers in superblock is protected by
'sbi->write_mutex', but each bio buffer area is independent, So we
should split write_mutex to three for DATA/NODE/META."
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This patch adds a slab cache entry for small discards.
Each entry consists of:
struct discard_entry {
struct list_head list; /* list head */
block_t blkaddr; /* block address to be discarded */
int len; /* # of consecutive blocks of the discard */
};
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
use genernal method supported by kernel
o changes from v1
If any waiter exists at end io, wake up it.
Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Previously, f2fs_sync_file() waits for all the node blocks to be written.
But, we don't need to do that, but wait only the inode-related node blocks.
This patch adds wait_on_node_pages_writeback() in which waits inode-related
node blocks that are on writeback.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
If you want to remove unnecessary BUG_ONs, you can just turn off F2FS_CHECK_FS
in your kernel config.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Previously, f2fs postpones reclaiming prefree segments into free segments
as much as possible.
However, if user writes and deletes a bunch of data without any sync or fsync
calls, some flash storages can suffer from garbage collections.
So, this patch adds the reclaiming codes to f2fs_write_node_pages and background
GC thread.
If there are a lot of prefree segments, let's do checkpoint so that f2fs
submits discard commands for the prefree regions to the flash storage.
Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Introduce the unfailed version of kmem_cache_alloc named f2fs_kmem_cache_alloc
to hide the retry routine and make the code a bit cleaner.
v2:
Fix the wrong use of 'retry' tag pointed out by Gao feng.
Use more neat code to remove redundant tag suggested by Haicheng Li.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Previously, do_checkpoint() will call congestion_wait() for waiting the pages
(previous submitted node/meta/data pages) to be written back.
Because congestion_wait() will set a regular period (e.g. HZ / 50 ) for waiting, and
no additional wake up mechanism was introduced if IO ends up before regular period costed.
Yuan Zhong found there is a situation that after the pages have been written back,
but the checkpoint thread still wait for congestion_wait to exit.
So here we store checkpoint task into f2fs_sb when doing checkpoint, it'll wait for IO completes
if there's IO going on, and in the end IO path, wake up checkpoint task when IO ends up.
Thanks to Yuan Zhong's pre work about this problem.
Reported-by: Yuan Zhong <yuan.mark.zhong@samsung.com>
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This patch removes the logic previously introduced to address the starvation
on cp_rwsem.
One potential there-in bug is that we should cover the wait.list with spin_lock,
but the previous code broke this rule.
And, actually current rwsem handles this starvation issue reasonably, so that we
didn't need to do this before neither.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
The fs_locks is used to block other ops(ex, recovery) when doing checkpoint.
And each other operate routine(besides checkpoint) needs to acquire a fs_lock,
there is a terrible problem here, if these are too many concurrency threads acquiring
fs_lock, so that they will block each other and may lead to some performance problem,
but this is not the phenomenon we want to see.
Though there are some optimization patches introduced to enhance the usage of fs_lock,
but the thorough solution is using a *rw_sem* to replace the fs_lock.
Checkpoint routine takes write_sem, and other ops take read_sem, so that we can block
other ops(ex, recovery) when doing checkpoint, and other ops will not disturb each other,
this can avoid the problem described above completely.
Because of the weakness of rw_sem, the above change may introduce a potential problem
that the checkpoint thread might get starved if other threads are intensively locking
the read semaphore for I/O.(Pointed out by Xu Jin)
In order to avoid this, a wait_list is introduced, the appending read semaphore ops
will be dropped into the wait_list if checkpoint thread is waiting for write semaphore,
and will be waked up when checkpoint thread gives up write semaphore.
Thanks to Kim's previous review and test, and will be very glad to see other guys'
performance tests about this patch.
V2:
-fix the potential starvation problem.
-use more suitable func name suggested by Xu Jin.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
[Jaegeuk Kim: adjust minor coding standard]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
There is a performance problem: when all sbi->fs_lock are holded, then
all the following threads may get the same next_lock value from sbi->next_lock_num
in function mutex_lock_op, and wait for the same lock(fs_lock[next_lock]),
it may cause performance reduce.
So we move the sbi->next_lock_num++ before getting lock, this will average the
following threads if all sbi->fs_lock are holded.
v1-->v2:
Drop the needless spin_lock as Jaegeuk suggested.
Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Yu Chao <chao2.yu@samsung.com>
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
0. modified inode structure
--------------------------------------
metadata (e.g., i_mtime, i_ctime, etc)
--------------------------------------
direct pointers [0 ~ 873]
inline xattrs (200 bytes by default)
indirect pointers [0 ~ 4]
--------------------------------------
node footer
--------------------------------------
1. setxattr flow
- read_all_xattrs copies all the xattrs from inline and xattr node block.
- handle xattr entries
- write_all_xattrs copies modified xattrs into inline and xattr node block.
2. getxattr flow
- read_all_xattrs copies all the xattrs from inline and xattr node block.
- check target entries
3. Usage
# mount -t f2fs -o inline_xattr $DEV $MNT
Once mounted with the inline_xattr option, f2fs marks all the newly created
files to reserve an amount of inline xattr space explicitly inside the inode
block. Without the mount option, f2fs will not touch any existing files and
newly created files as well.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This patch enables the number of direct pointers inside on-disk inode block to
be changed dynamically according to the size of inline xattr space.
The number of direct pointers, ADDRS_PER_INODE, can be changed only if the file
has inline xattr flag.
The number of direct pointers that will be used by inline xattrs is defined as
F2FS_INLINE_XATTR_ADDRS.
Current patch assigns F2FS_INLINE_XATTR_ADDRS to 0 temporarily.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This patch adds basic inode flags for inline xattrs, F2FS_INLINE_XATTR,
and add a mount option, inline_xattr, which is enabled when xattr is set.
If the mount option is enabled, all the files are marked with the inline_xattrs
flag.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Gu Zheng
Jaegeuk Kim
Changman Lee
Haicheng Li
Yu Chao