2017-11-27 06:56:46

by Yunlong Song

[permalink] [raw]
Subject: [PATCH] f2fs: avoid false positive of free secs check

Sometimes f2fs_gc is called with no target victim (e.g. xfstest
generic/027, ndirty_node:545 ndiry_dent:1 ndirty_imeta:513 rsvd_segs:21
free_segs:27, has_not_enough_free_secs will return true). This patch
first merges pages and then converts into sections.

Signed-off-by: Yunlong Song <[email protected]>
---
fs/f2fs/f2fs.h | 9 ---------
fs/f2fs/segment.c | 12 +++++++-----
fs/f2fs/segment.h | 13 +++++++++----
3 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ca6b0c9..e89cff7 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1675,15 +1675,6 @@ static inline int get_dirty_pages(struct inode *inode)
return atomic_read(&F2FS_I(inode)->dirty_pages);
}

-static inline int get_blocktype_secs(struct f2fs_sb_info *sbi, int block_type)
-{
- unsigned int pages_per_sec = sbi->segs_per_sec * sbi->blocks_per_seg;
- unsigned int segs = (get_pages(sbi, block_type) + pages_per_sec - 1) >>
- sbi->log_blocks_per_seg;
-
- return segs / sbi->segs_per_sec;
-}
-
static inline block_t valid_user_blocks(struct f2fs_sb_info *sbi)
{
return sbi->total_valid_block_count;
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c117e09..603f805 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -171,17 +171,19 @@ static unsigned long __find_rev_next_zero_bit(const unsigned long *addr,

bool need_SSR(struct f2fs_sb_info *sbi)
{
- int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES);
- int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS);
- int imeta_secs = get_blocktype_secs(sbi, F2FS_DIRTY_IMETA);
+ s64 node_pages = get_pages(sbi, F2FS_DIRTY_NODES);
+ s64 dent_pages = get_pages(sbi, F2FS_DIRTY_DENTS);
+ s64 imeta_pages = get_pages(sbi, F2FS_DIRTY_IMETA);

if (test_opt(sbi, LFS))
return false;
if (sbi->gc_thread && sbi->gc_thread->gc_urgent)
return true;

- return free_sections(sbi) <= (node_secs + 2 * dent_secs + imeta_secs +
- SM_I(sbi)->min_ssr_sections + reserved_sections(sbi));
+ return free_sections(sbi) <=
+ (PAGE2SEC(sbi, node_pages + imeta_pages) +
+ PAGE2SEC(sbi, 2 * dent_pages) +
+ SM_I(sbi)->min_ssr_sections + reserved_sections(sbi));
}

void register_inmem_page(struct inode *inode, struct page *page)
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index d1d394c..723d79e 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -115,6 +115,10 @@
#define SECTOR_TO_BLOCK(sectors) \
((sectors) >> F2FS_LOG_SECTORS_PER_BLOCK)

+#define PAGE2SEC(sbi, pages) \
+ ((((pages) + BLKS_PER_SEC(sbi) - 1) \
+ >> sbi->log_blocks_per_seg) / sbi->segs_per_sec)
+
/*
* indicate a block allocation direction: RIGHT and LEFT.
* RIGHT means allocating new sections towards the end of volume.
@@ -527,9 +531,9 @@ static inline bool has_curseg_enough_space(struct f2fs_sb_info *sbi)
static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi,
int freed, int needed)
{
- int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES);
- int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS);
- int imeta_secs = get_blocktype_secs(sbi, F2FS_DIRTY_IMETA);
+ s64 node_pages = get_pages(sbi, F2FS_DIRTY_NODES);
+ s64 dent_pages = get_pages(sbi, F2FS_DIRTY_DENTS);
+ s64 imeta_pages = get_pages(sbi, F2FS_DIRTY_IMETA);

if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
return false;
@@ -538,7 +542,8 @@ static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi,
has_curseg_enough_space(sbi))
return false;
return (free_sections(sbi) + freed) <=
- (node_secs + 2 * dent_secs + imeta_secs +
+ (PAGE2SEC(sbi, node_pages + imeta_pages) +
+ PAGE2SEC(sbi, 2 * dent_pages) +
reserved_sections(sbi) + needed);
}

--
1.8.5.2


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