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Date:   Thu, 22 Aug 2019 10:47:36 -0700
From:   Jaegeuk Kim <jaegeuk@kernel.org>
To:     Chao Yu <yuchao0@huawei.com>
Cc:     linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net
Subject: Re: [f2fs-dev] [PATCH v2] f2fs: allocate memory in batch in
 build_sit_info()
Message-ID: <20190822174736.GA88722@jaegeuk-macbookpro.roam.corp.google.com>
References: <20190726074120.3278-1-yuchao0@huawei.com>
 <20190819202007.GA23891@jaegeuk-macbookpro.roam.corp.google.com>
 <99a2713a-50d2-8a77-87d9-661ab7ed3a0c@huawei.com>
 <20190820174121.GB58214@jaegeuk-macbookpro.roam.corp.google.com>
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On 08/20, Jaegeuk Kim wrote:
> On 08/20, Chao Yu wrote:
> > On 2019/8/20 4:20, Jaegeuk Kim wrote:
> > > On 07/26, Chao Yu wrote:
> > >> build_sit_info() allocate all bitmaps for each segment one by one,
> > >> it's quite low efficiency, this pach changes to allocate large
> > >> continuous memory at a time, and divide it and assign for each bitmaps
> > >> of segment. For large size image, it can expect improving its mount
> > >> speed.
> > > 
> > > Hmm, I hit a kernel panic when mounting a partition during fault injection test:
> > > 
> > > 726 #ifdef CONFIG_F2FS_CHECK_FS
> > > 727         if (f2fs_test_bit(offset, sit_i->sit_bitmap) !=
> > > 728                         f2fs_test_bit(offset, sit_i->sit_bitmap_mir))
> > > 729                 f2fs_bug_on(sbi, 1);
> > > 730 #endif
> > 
> > We didn't change anything about sit_i->sit_bitmap{_mir,}, it's so wired we panic
> > here... :(
> > 
> > I double check the change, but find nothing suspicious, btw, my fault injection
> > testcase shows normal.
> > 
> > Jaegeuk, do you have any idea about this issue?
> 
> I'm bisecting. :P

It was caused by wrong bitmap size in "f2fs: Fix indefinite loop in f2fs_gc()".
Fixed by:
---
 fs/f2fs/segment.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9b20ce3b87cc..cc230fc829e1 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3950,7 +3950,7 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 	struct sit_info *sit_i;
 	unsigned int sit_segs, start;
 	char *src_bitmap, *bitmap;
-	unsigned int bitmap_size;
+	unsigned int bitmap_size, main_bitmap_size, sit_bitmap_size;
 
 	/* allocate memory for SIT information */
 	sit_i = f2fs_kzalloc(sbi, sizeof(struct sit_info), GFP_KERNEL);
@@ -3966,8 +3966,8 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 	if (!sit_i->sentries)
 		return -ENOMEM;
 
-	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
-	sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(sbi, bitmap_size,
+	main_bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
+	sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(sbi, main_bitmap_size,
 								GFP_KERNEL);
 	if (!sit_i->dirty_sentries_bitmap)
 		return -ENOMEM;
@@ -4016,19 +4016,21 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 	sit_segs = le32_to_cpu(raw_super->segment_count_sit) >> 1;
 
 	/* setup SIT bitmap from ckeckpoint pack */
-	bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
+	sit_bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
 	src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
 
-	sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
+	sit_i->sit_bitmap = kmemdup(src_bitmap, sit_bitmap_size, GFP_KERNEL);
 	if (!sit_i->sit_bitmap)
 		return -ENOMEM;
 
 #ifdef CONFIG_F2FS_CHECK_FS
-	sit_i->sit_bitmap_mir = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
+	sit_i->sit_bitmap_mir = kmemdup(src_bitmap,
+					sit_bitmap_size, GFP_KERNEL);
 	if (!sit_i->sit_bitmap_mir)
 		return -ENOMEM;
 
-	sit_i->invalid_segmap = f2fs_kvzalloc(sbi, bitmap_size, GFP_KERNEL);
+	sit_i->invalid_segmap = f2fs_kvzalloc(sbi,
+					main_bitmap_size, GFP_KERNEL);
 	if (!sit_i->invalid_segmap)
 		return -ENOMEM;
 #endif
@@ -4039,7 +4041,7 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
 	sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
 	sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
 	sit_i->written_valid_blocks = 0;
-	sit_i->bitmap_size = bitmap_size;
+	sit_i->bitmap_size = sit_bitmap_size;
 	sit_i->dirty_sentries = 0;
 	sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
 	sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
-- 
2.19.0.605.g01d371f741-goog

> 
> > 
> > Thanks,
> > 
> > > 
> > > For your information, I'm testing without this patch.
> > > 
> > > Thanks,
> > > 
> > >>
> > >> Signed-off-by: Chen Gong <gongchen4@huawei.com>
> > >> Signed-off-by: Chao Yu <yuchao0@huawei.com>
> > >> ---
> > >> v2:
> > >> - fix warning triggered in kmalloc() if requested memory size exceeds 4MB.
> > >>  fs/f2fs/segment.c | 51 +++++++++++++++++++++--------------------------
> > >>  fs/f2fs/segment.h |  1 +
> > >>  2 files changed, 24 insertions(+), 28 deletions(-)
> > >>
> > >> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > >> index a661ac32e829..d720eacd9c57 100644
> > >> --- a/fs/f2fs/segment.c
> > >> +++ b/fs/f2fs/segment.c
> > >> @@ -3941,7 +3941,7 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
> > >>  	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
> > >>  	struct sit_info *sit_i;
> > >>  	unsigned int sit_segs, start;
> > >> -	char *src_bitmap;
> > >> +	char *src_bitmap, *bitmap;
> > >>  	unsigned int bitmap_size;
> > >>  
> > >>  	/* allocate memory for SIT information */
> > >> @@ -3964,27 +3964,31 @@ static int build_sit_info(struct f2fs_sb_info *sbi)
> > >>  	if (!sit_i->dirty_sentries_bitmap)
> > >>  		return -ENOMEM;
> > >>  
> > >> +#ifdef CONFIG_F2FS_CHECK_FS
> > >> +	bitmap_size = MAIN_SEGS(sbi) * SIT_VBLOCK_MAP_SIZE * 4;
> > >> +#else
> > >> +	bitmap_size = MAIN_SEGS(sbi) * SIT_VBLOCK_MAP_SIZE * 3;
> > >> +#endif
> > >> +	sit_i->bitmap = f2fs_kvzalloc(sbi, bitmap_size, GFP_KERNEL);
> > >> +	if (!sit_i->bitmap)
> > >> +		return -ENOMEM;
> > >> +
> > >> +	bitmap = sit_i->bitmap;
> > >> +
> > >>  	for (start = 0; start < MAIN_SEGS(sbi); start++) {
> > >> -		sit_i->sentries[start].cur_valid_map
> > >> -			= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
> > >> -		sit_i->sentries[start].ckpt_valid_map
> > >> -			= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
> > >> -		if (!sit_i->sentries[start].cur_valid_map ||
> > >> -				!sit_i->sentries[start].ckpt_valid_map)
> > >> -			return -ENOMEM;
> > >> +		sit_i->sentries[start].cur_valid_map = bitmap;
> > >> +		bitmap += SIT_VBLOCK_MAP_SIZE;
> > >> +
> > >> +		sit_i->sentries[start].ckpt_valid_map = bitmap;
> > >> +		bitmap += SIT_VBLOCK_MAP_SIZE;
> > >>  
> > >>  #ifdef CONFIG_F2FS_CHECK_FS
> > >> -		sit_i->sentries[start].cur_valid_map_mir
> > >> -			= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
> > >> -		if (!sit_i->sentries[start].cur_valid_map_mir)
> > >> -			return -ENOMEM;
> > >> +		sit_i->sentries[start].cur_valid_map_mir = bitmap;
> > >> +		bitmap += SIT_VBLOCK_MAP_SIZE;
> > >>  #endif
> > >>  
> > >> -		sit_i->sentries[start].discard_map
> > >> -			= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE,
> > >> -							GFP_KERNEL);
> > >> -		if (!sit_i->sentries[start].discard_map)
> > >> -			return -ENOMEM;
> > >> +		sit_i->sentries[start].discard_map = bitmap;
> > >> +		bitmap += SIT_VBLOCK_MAP_SIZE;
> > >>  	}
> > >>  
> > >>  	sit_i->tmp_map = f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
> > >> @@ -4492,21 +4496,12 @@ static void destroy_free_segmap(struct f2fs_sb_info *sbi)
> > >>  static void destroy_sit_info(struct f2fs_sb_info *sbi)
> > >>  {
> > >>  	struct sit_info *sit_i = SIT_I(sbi);
> > >> -	unsigned int start;
> > >>  
> > >>  	if (!sit_i)
> > >>  		return;
> > >>  
> > >> -	if (sit_i->sentries) {
> > >> -		for (start = 0; start < MAIN_SEGS(sbi); start++) {
> > >> -			kvfree(sit_i->sentries[start].cur_valid_map);
> > >> -#ifdef CONFIG_F2FS_CHECK_FS
> > >> -			kvfree(sit_i->sentries[start].cur_valid_map_mir);
> > >> -#endif
> > >> -			kvfree(sit_i->sentries[start].ckpt_valid_map);
> > >> -			kvfree(sit_i->sentries[start].discard_map);
> > >> -		}
> > >> -	}
> > >> +	if (sit_i->sentries)
> > >> +		kvfree(sit_i->bitmap);
> > >>  	kvfree(sit_i->tmp_map);
> > >>  
> > >>  	kvfree(sit_i->sentries);
> > >> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
> > >> index b74602813a05..ec4d568fd58c 100644
> > >> --- a/fs/f2fs/segment.h
> > >> +++ b/fs/f2fs/segment.h
> > >> @@ -226,6 +226,7 @@ struct sit_info {
> > >>  	block_t sit_base_addr;		/* start block address of SIT area */
> > >>  	block_t sit_blocks;		/* # of blocks used by SIT area */
> > >>  	block_t written_valid_blocks;	/* # of valid blocks in main area */
> > >> +	char *bitmap;			/* all bitmaps pointer */
> > >>  	char *sit_bitmap;		/* SIT bitmap pointer */
> > >>  #ifdef CONFIG_F2FS_CHECK_FS
> > >>  	char *sit_bitmap_mir;		/* SIT bitmap mirror */
> > >> -- 
> > >> 2.18.0.rc1
> > > .
> > > 
> 
> 
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