[PATCH 1/2] f2fs: trigger GC when there are prefree segments

[PATCH 1/2] f2fs: trigger GC when there are prefree segments

[Jaegeuk Kim]

Previously, f2fs conducts SSR when free_sections() < overprovision_sections.
But, even though there are a lot of prefree segments, it can consider SSR only.
So, let's consider the number of prefree segments too for triggering SSR.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
---
 fs/f2fs/segment.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 062424a..cd9bd93 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -453,7 +453,8 @@ static inline int reserved_sections(struct f2fs_sb_info *sbi)
 
 static inline bool need_SSR(struct f2fs_sb_info *sbi)
 {
-	return (free_sections(sbi) < overprovision_sections(sbi));
+	return ((prefree_segments(sbi) / sbi->segs_per_sec)
+			+ free_sections(sbi) < overprovision_sections(sbi));
 }
 
 static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi, int freed)
-- 
1.8.3.1.437.g0dbd812

[PATCH 1/2] f2fs: trigger GC when there are prefree segments

[Jaegeuk Kim]

Previously, f2fs conducts SSR when free_sections() < overprovision_sections.
But, even though there are a lot of prefree segments, it can consider SSR only.
So, let's consider the number of prefree segments too for triggering SSR.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
---
 fs/f2fs/segment.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 062424a..cd9bd93 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -453,7 +453,8 @@ static inline int reserved_sections(struct f2fs_sb_info *sbi)
 
 static inline bool need_SSR(struct f2fs_sb_info *sbi)
 {
-	return (free_sections(sbi) < overprovision_sections(sbi));
+	return ((prefree_segments(sbi) / sbi->segs_per_sec)
+			+ free_sections(sbi) < overprovision_sections(sbi));
 }
 
 static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi, int freed)
-- 
1.8.3.1.437.g0dbd812


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[PATCH 2/2] f2fs: avoid an overflow during utilization calculation

[Jaegeuk Kim]

The current f2fs uses all the block counts with 32 bit numbers, which is able to
cover about 15TB volume.

But in calculation of utilization, f2fs multiplies the count by 100 which can
induce overflow.
This patch fixes this.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
---
 fs/f2fs/segment.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index cd9bd93..e0d6d3a 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -471,7 +471,7 @@ static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi, int freed)
 
 static inline int utilization(struct f2fs_sb_info *sbi)
 {
-	return div_u64(valid_user_blocks(sbi) * 100, sbi->user_block_count);
+	return div_u64((u64)valid_user_blocks(sbi) * 100, sbi->user_block_count);
 }
 
 /*
-- 
1.8.3.1.437.g0dbd812

[PATCH 2/2] f2fs: avoid an overflow during utilization calculation

[Jaegeuk Kim]

The current f2fs uses all the block counts with 32 bit numbers, which is able to
cover about 15TB volume.

But in calculation of utilization, f2fs multiplies the count by 100 which can
induce overflow.
This patch fixes this.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
---
 fs/f2fs/segment.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index cd9bd93..e0d6d3a 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -471,7 +471,7 @@ static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi, int freed)
 
 static inline int utilization(struct f2fs_sb_info *sbi)
 {
-	return div_u64(valid_user_blocks(sbi) * 100, sbi->user_block_count);
+	return div_u64((u64)valid_user_blocks(sbi) * 100, sbi->user_block_count);
 }
 
 /*
-- 
1.8.3.1.437.g0dbd812


------------------------------------------------------------------------------
Learn the latest--Visual Studio 2012, SharePoint 2013, SQL 2012, more!
Discover the easy way to master current and previous Microsoft technologies
and advance your career. Get an incredible 1,500+ hours of step-by-step
tutorial videos with LearnDevNow. Subscribe today and save!
http://pubads.g.doubleclick.net/gampad/clk?id=58040911&iu=/4140/ostg.clktrk