* Re: 4.9.23: hang on sync
2017-04-20 15:16 ` William Brana
@ 2017-04-21 0:49 ` Jaegeuk Kim
0 siblings, 0 replies; 3+ messages in thread
From: Jaegeuk Kim @ 2017-04-21 0:49 UTC (permalink / raw)
To: William Brana; +Cc: linux-f2fs-devel
Hi William,
On 04/20, William Brana wrote:
> steps to reproduce:
> 1) mkfs
> 2) mount
> 3) untar
> 4) sync
> sync seems to write huge amount of data with size which exceeds size
> of partition
> it seems to related to -s 12 ( 24 MB is block size of SSD )
Thank you so much for the report.
I reproduced this and found some bugs in f2fs. I wrote a patch to resovle this
like below. But I tested in latest f2fs tho.
Will take a look at backport to v4.9 when it goes to stable trees.
Thanks
>From ce5b8d44788f0074112c752e3282ae9eba5052c5 Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Thu, 20 Apr 2017 13:51:57 -0700
Subject: [PATCH] f2fs: fix out-of free segments
This patch also reverts d0db7703ac1 ("f2fs: do SSR in higher priority").
This patch fixes out of free segments caused by many small file creation by
1) mkfs -s 1 2G
2) mount
3) untar
- preoduce 60000 small files burstly
4) sync
- flush node pages
- flush imeta
Here, when we do f2fs_balance_fs, we missed # of imeta blocks, resulting in
skipping to check has_not_enough_free_secs.
Another test is done by
1) mkfs -s 12 2G
2) mount
3) untar
- preoduce 60000 small files burstly
4) sync
- flush node pages
- flush imeta
In this case, this patch also fixes wrong block allocation under large section
size.
Reported-by: William Brana <wbrana@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/data.c | 3 ++-
fs/f2fs/inode.c | 3 ++-
fs/f2fs/segment.c | 26 +++++++++++++++++++++-----
3 files changed, 25 insertions(+), 7 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 7d46a8e6d350..b8dcd1e224e8 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1472,7 +1472,8 @@ static int __write_data_page(struct page *page, bool *submitted,
}
unlock_page(page);
- f2fs_balance_fs(sbi, need_balance_fs);
+ if (!S_ISDIR(inode->i_mode))
+ f2fs_balance_fs(sbi, need_balance_fs);
if (unlikely(f2fs_cp_error(sbi))) {
f2fs_submit_merged_bio(sbi, DATA, WRITE);
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 0900814485c7..518f49643092 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -338,7 +338,8 @@ int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
* We need to balance fs here to prevent from producing dirty node pages
* during the urgent cleaning time when runing out of free sections.
*/
- if (update_inode_page(inode) && wbc && wbc->nr_to_write)
+ update_inode_page(inode);
+ if (wbc && wbc->nr_to_write)
f2fs_balance_fs(sbi, true);
return 0;
}
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index d4bda1e54475..2a95535794ca 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -388,11 +388,8 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
}
#endif
- if (!need)
- return;
-
/* balance_fs_bg is able to be pending */
- if (excess_cached_nats(sbi))
+ if (need && excess_cached_nats(sbi))
f2fs_balance_fs_bg(sbi);
/*
@@ -1639,6 +1636,17 @@ static void write_current_sum_page(struct f2fs_sb_info *sbi,
f2fs_put_page(page, 1);
}
+static int is_next_segment_free(struct f2fs_sb_info *sbi, int type)
+{
+ struct curseg_info *curseg = CURSEG_I(sbi, type);
+ unsigned int segno = curseg->segno + 1;
+ struct free_segmap_info *free_i = FREE_I(sbi);
+
+ if (segno < MAIN_SEGS(sbi) && segno % sbi->segs_per_sec)
+ return !test_bit(segno, free_i->free_segmap);
+ return 0;
+}
+
/*
* Find a new segment from the free segments bitmap to right order
* This function should be returned with success, otherwise BUG
@@ -1752,6 +1760,10 @@ static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
{
+ /* if segs_per_sec is large than 1, we need to keep original policy. */
+ if (sbi->segs_per_sec != 1)
+ return CURSEG_I(sbi, type)->segno;
+
if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
return 0;
@@ -1901,17 +1913,21 @@ static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
int type, bool force)
{
+ struct curseg_info *curseg = CURSEG_I(sbi, type);
+
if (force)
new_curseg(sbi, type, true);
else if (!is_set_ckpt_flags(sbi, CP_CRC_RECOVERY_FLAG) &&
type == CURSEG_WARM_NODE)
new_curseg(sbi, type, false);
+ else if (curseg->alloc_type == LFS && is_next_segment_free(sbi, type))
+ new_curseg(sbi, type, false);
else if (need_SSR(sbi) && get_ssr_segment(sbi, type))
change_curseg(sbi, type, true);
else
new_curseg(sbi, type, false);
- stat_inc_seg_type(sbi, CURSEG_I(sbi, type));
+ stat_inc_seg_type(sbi, curseg);
}
void allocate_new_segments(struct f2fs_sb_info *sbi)
--
2.11.0
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
^ permalink raw reply related [flat|nested] 3+ messages in thread