[PATCH 04/10] f2fs: give an option to enable in-place-updates during fsync to users

From: Jaegeuk Kim
Date: Sun Sep 14 2014 - 18:16:55 EST


If user wrote F2FS_IPU_FSYNC:4 in /sys/fs/f2fs/ipu_policy, f2fs_sync_file
only starts to try in-place-updates.
And, if the number of dirty pages is over /sys/fs/f2fs/min_fsync_blocks, it
keeps out-of-order manner. Otherwise, it triggers in-place-updates.

This may be used by storage showing very high random write performance.

For example, it can be used when,

Seq. writes (Data) + wait + Seq. writes (Node)

is pretty much slower than,

Rand. writes (Data)

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-fs-f2fs | 7 +++++++
Documentation/filesystems/f2fs.txt | 9 ++++++++-
fs/f2fs/f2fs.h | 1 +
fs/f2fs/file.c | 7 +++----
fs/f2fs/segment.c | 3 ++-
fs/f2fs/segment.h | 14 ++++++++++----
fs/f2fs/super.c | 2 ++
7 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 62dd725..6f9157f 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -44,6 +44,13 @@ Description:
Controls the FS utilization condition for the in-place-update
policies.

+What: /sys/fs/f2fs/<disk>/min_fsync_blocks
+Date: September 2014
+Contact: "Jaegeuk Kim" <jaegeuk@xxxxxxxxxx>
+Description:
+ Controls the dirty page count condition for the in-place-update
+ policies.
+
What: /sys/fs/f2fs/<disk>/max_small_discards
Date: November 2013
Contact: "Jaegeuk Kim" <jaegeuk.kim@xxxxxxxxxxx>
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index a2046a7..d010da8 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -194,13 +194,20 @@ Files in /sys/fs/f2fs/<devname>
updates in f2fs. There are five policies:
0: F2FS_IPU_FORCE, 1: F2FS_IPU_SSR,
2: F2FS_IPU_UTIL, 3: F2FS_IPU_SSR_UTIL,
- 4: F2FS_IPU_DISABLE.
+ 4: F2FS_IPU_FSYNC, 5: F2FS_IPU_DISABLE.

min_ipu_util This parameter controls the threshold to trigger
in-place-updates. The number indicates percentage
of the filesystem utilization, and used by
F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies.

+ min_fsync_blocks This parameter controls the threshold to trigger
+ in-place-updates when F2FS_IPU_FSYNC mode is set.
+ The number indicates the number of dirty pages
+ when fsync needs to flush on its call path. If
+ the number is less than this value, it triggers
+ in-place-updates.
+
max_victim_search This parameter controls the number of trials to
find a victim segment when conducting SSR and
cleaning operations. The default value is 4096
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2756c16..4f84d2a 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -386,6 +386,7 @@ struct f2fs_sm_info {

unsigned int ipu_policy; /* in-place-update policy */
unsigned int min_ipu_util; /* in-place-update threshold */
+ unsigned int min_fsync_blocks; /* threshold for fsync */

/* for flush command control */
struct flush_cmd_control *cmd_control_info;
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 77426c7..af06e22 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -154,12 +154,11 @@ int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
trace_f2fs_sync_file_enter(inode);

/* if fdatasync is triggered, let's do in-place-update */
- if (datasync)
+ if (get_dirty_pages(inode) <= SM_I(sbi)->min_fsync_blocks)
set_inode_flag(fi, FI_NEED_IPU);
-
ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
- if (datasync)
- clear_inode_flag(fi, FI_NEED_IPU);
+ clear_inode_flag(fi, FI_NEED_IPU);
+
if (ret) {
trace_f2fs_sync_file_exit(inode, need_cp, datasync, ret);
return ret;
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index e158d63..c6f627b 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1928,8 +1928,9 @@ int build_segment_manager(struct f2fs_sb_info *sbi)
sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
sm_info->rec_prefree_segments = sm_info->main_segments *
DEF_RECLAIM_PREFREE_SEGMENTS / 100;
- sm_info->ipu_policy = F2FS_IPU_DISABLE;
+ sm_info->ipu_policy = F2FS_IPU_FSYNC;
sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
+ sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;

INIT_LIST_HEAD(&sm_info->discard_list);
sm_info->nr_discards = 0;
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index bed0dc9..013aed2 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -472,15 +472,20 @@ static inline int utilization(struct f2fs_sb_info *sbi)
* F2FS_IPU_UTIL - if FS utilization is over threashold,
* F2FS_IPU_SSR_UTIL - if SSR mode is activated and FS utilization is over
* threashold,
+ * F2FS_IPU_FSYNC - activated in fsync path only for high performance flash
+ * storages. IPU will be triggered only if the # of dirty
+ * pages over min_fsync_blocks.
* F2FS_IPUT_DISABLE - disable IPU. (=default option)
*/
#define DEF_MIN_IPU_UTIL 70
+#define DEF_MIN_FSYNC_BLOCKS 8

enum {
F2FS_IPU_FORCE,
F2FS_IPU_SSR,
F2FS_IPU_UTIL,
F2FS_IPU_SSR_UTIL,
+ F2FS_IPU_FSYNC,
F2FS_IPU_DISABLE,
};

@@ -492,10 +497,6 @@ static inline bool need_inplace_update(struct inode *inode)
if (S_ISDIR(inode->i_mode))
return false;

- /* this is only set during fdatasync */
- if (is_inode_flag_set(F2FS_I(inode), FI_NEED_IPU))
- return true;
-
switch (SM_I(sbi)->ipu_policy) {
case F2FS_IPU_FORCE:
return true;
@@ -511,6 +512,11 @@ static inline bool need_inplace_update(struct inode *inode)
if (need_SSR(sbi) && utilization(sbi) > SM_I(sbi)->min_ipu_util)
return true;
break;
+ case F2FS_IPU_FSYNC:
+ /* this is only set during fdatasync */
+ if (is_inode_flag_set(F2FS_I(inode), FI_NEED_IPU))
+ return true;
+ break;
case F2FS_IPU_DISABLE:
break;
}
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index b5af9be..ed4095e 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -190,6 +190,7 @@ F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, max_small_discards, max_discards);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
+F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks);
F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
@@ -204,6 +205,7 @@ static struct attribute *f2fs_attrs[] = {
ATTR_LIST(max_small_discards),
ATTR_LIST(ipu_policy),
ATTR_LIST(min_ipu_util),
+ ATTR_LIST(min_fsync_blocks),
ATTR_LIST(max_victim_search),
ATTR_LIST(dir_level),
ATTR_LIST(ram_thresh),
--
1.8.5.2 (Apple Git-48)

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