[PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery

[PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery

[Jaegeuk Kim]

Previously, we used cp_version only to detect recoverable dnodes.
In order to avoid same garbage cp_version, we needed to truncate the next
dnode during checkpoint, resulting in additional discard or data write.
If we can distinguish this by using crc in addition to cp_version, we can
remove this overhead.

There is backward compatibility concern where it changes node_footer layout.
But, it only affects the direct nodes written after the last checkpoint.
We simply expect that user would change kernel versions back and forth after
stable checkpoint.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/checkpoint.c | 18 -------------
 fs/f2fs/f2fs.h       |  1 -
 fs/f2fs/node.h       | 73 ++++++++++++++++++++++++++++++++--------------------
 fs/f2fs/recovery.c   | 36 +++++---------------------
 fs/f2fs/segment.c    | 22 ----------------
 fs/f2fs/super.c      |  5 +++-
 6 files changed, 55 insertions(+), 100 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index df56a43..6ecc5b8 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -992,7 +992,6 @@ static void wait_on_all_pages_writeback(struct f2fs_sb_info *sbi)
 static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
-	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num;
 	nid_t last_nid = nm_i->next_scan_nid;
@@ -1001,19 +1000,10 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	__u32 crc32 = 0;
 	int i;
 	int cp_payload_blks = __cp_payload(sbi);
-	block_t discard_blk = NEXT_FREE_BLKADDR(sbi, curseg);
-	bool invalidate = false;
 	struct super_block *sb = sbi->sb;
 	struct curseg_info *seg_i = CURSEG_I(sbi, CURSEG_HOT_NODE);
 	u64 kbytes_written;
 
-	/*
-	 * This avoids to conduct wrong roll-forward operations and uses
-	 * metapages, so should be called prior to sync_meta_pages below.
-	 */
-	if (!test_opt(sbi, LFS) && discard_next_dnode(sbi, discard_blk))
-		invalidate = true;
-
 	/* Flush all the NAT/SIT pages */
 	while (get_pages(sbi, F2FS_DIRTY_META)) {
 		sync_meta_pages(sbi, META, LONG_MAX);
@@ -1154,14 +1144,6 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	/* wait for previous submitted meta pages writeback */
 	wait_on_all_pages_writeback(sbi);
 
-	/*
-	 * invalidate meta page which is used temporarily for zeroing out
-	 * block at the end of warm node chain.
-	 */
-	if (invalidate)
-		invalidate_mapping_pages(META_MAPPING(sbi), discard_blk,
-								discard_blk);
-
 	release_ino_entry(sbi, false);
 
 	if (unlikely(f2fs_cp_error(sbi)))
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 132756c..a472191 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2065,7 +2065,6 @@ void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t);
 void f2fs_wait_all_discard_bio(struct f2fs_sb_info *);
 void clear_prefree_segments(struct f2fs_sb_info *, struct cp_control *);
 void release_discard_addrs(struct f2fs_sb_info *);
-bool discard_next_dnode(struct f2fs_sb_info *, block_t);
 int npages_for_summary_flush(struct f2fs_sb_info *, bool);
 void allocate_new_segments(struct f2fs_sb_info *);
 int f2fs_trim_fs(struct f2fs_sb_info *, struct fstrim_range *);
diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index fc76845..e8114f9 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -229,6 +229,37 @@ static inline void set_to_next_nat(struct f2fs_nm_info *nm_i, nid_t start_nid)
 	f2fs_change_bit(block_off, nm_i->nat_bitmap);
 }
 
+static inline nid_t ino_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.ino);
+}
+
+static inline nid_t nid_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.nid);
+}
+
+static inline unsigned int ofs_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	unsigned flag = le32_to_cpu(rn->footer.flag);
+	return flag >> OFFSET_BIT_SHIFT;
+}
+
+static inline __u64 cpver_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le64_to_cpu(rn->footer.cp_ver);
+}
+
+static inline block_t next_blkaddr_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.next_blkaddr);
+}
+
 static inline void fill_node_footer(struct page *page, nid_t nid,
 				nid_t ino, unsigned int ofs, bool reset)
 {
@@ -259,40 +290,26 @@ static inline void fill_node_footer_blkaddr(struct page *page, block_t blkaddr)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
 	struct f2fs_node *rn = F2FS_NODE(page);
+	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
+	__u64 cp_ver = le64_to_cpu(ckpt->checkpoint_ver);
+	__u64 crc;
 
-	rn->footer.cp_ver = ckpt->checkpoint_ver;
+	crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset)));
+	cp_ver |= (crc << 32);
+	rn->footer.cp_ver = cpu_to_le64(cp_ver);
 	rn->footer.next_blkaddr = cpu_to_le32(blkaddr);
 }
 
-static inline nid_t ino_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le32_to_cpu(rn->footer.ino);
-}
-
-static inline nid_t nid_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le32_to_cpu(rn->footer.nid);
-}
-
-static inline unsigned int ofs_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	unsigned flag = le32_to_cpu(rn->footer.flag);
-	return flag >> OFFSET_BIT_SHIFT;
-}
-
-static inline unsigned long long cpver_of_node(struct page *node_page)
+static inline bool is_recoverable_dnode(struct page *page)
 {
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le64_to_cpu(rn->footer.cp_ver);
-}
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
+	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
+	__u64 cp_ver = cur_cp_version(ckpt);
+	__u64 crc;
 
-static inline block_t next_blkaddr_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le32_to_cpu(rn->footer.next_blkaddr);
+	crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset)));
+	cp_ver |= (crc << 32);
+	return cpu_to_le64(cp_ver) == cpver_of_node(page);
 }
 
 /*
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index ad748e5..2b8a56d 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -224,7 +224,6 @@ static bool is_same_inode(struct inode *inode, struct page *ipage)
 
 static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
 {
-	unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
 	struct curseg_info *curseg;
 	struct page *page = NULL;
 	block_t blkaddr;
@@ -242,7 +241,7 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
 
 		page = get_tmp_page(sbi, blkaddr);
 
-		if (cp_ver != cpver_of_node(page))
+		if (!is_recoverable_dnode(page))
 			break;
 
 		if (!is_fsync_dnode(page))
@@ -516,7 +515,6 @@ out:
 static int recover_data(struct f2fs_sb_info *sbi, struct list_head *inode_list,
 						struct list_head *dir_list)
 {
-	unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
 	struct curseg_info *curseg;
 	struct page *page = NULL;
 	int err = 0;
@@ -536,7 +534,7 @@ static int recover_data(struct f2fs_sb_info *sbi, struct list_head *inode_list,
 
 		page = get_tmp_page(sbi, blkaddr);
 
-		if (cp_ver != cpver_of_node(page)) {
+		if (!is_recoverable_dnode(page)) {
 			f2fs_put_page(page, 1);
 			break;
 		}
@@ -628,37 +626,15 @@ out:
 	}
 
 	clear_sbi_flag(sbi, SBI_POR_DOING);
-	if (err) {
-		bool invalidate = false;
-
-		if (test_opt(sbi, LFS)) {
-			update_meta_page(sbi, NULL, blkaddr);
-			invalidate = true;
-		} else if (discard_next_dnode(sbi, blkaddr)) {
-			invalidate = true;
-		}
-
-		f2fs_wait_all_discard_bio(sbi);
-
-		/* Flush all the NAT/SIT pages */
-		while (get_pages(sbi, F2FS_DIRTY_META))
-			sync_meta_pages(sbi, META, LONG_MAX);
-
-		/* invalidate temporary meta page */
-		if (invalidate)
-			invalidate_mapping_pages(META_MAPPING(sbi),
-							blkaddr, blkaddr);
-
+	if (err)
 		set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
-		mutex_unlock(&sbi->cp_mutex);
-	} else if (need_writecp) {
+	mutex_unlock(&sbi->cp_mutex);
+
+	if (!err && need_writecp) {
 		struct cp_control cpc = {
 			.reason = CP_RECOVERY,
 		};
-		mutex_unlock(&sbi->cp_mutex);
 		err = write_checkpoint(sbi, &cpc);
-	} else {
-		mutex_unlock(&sbi->cp_mutex);
 	}
 
 	destroy_fsync_dnodes(&dir_list);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 101b58f..4376326 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -669,28 +669,6 @@ static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
 	return __f2fs_issue_discard_async(sbi, start, len, GFP_NOFS, 0);
 }
 
-bool discard_next_dnode(struct f2fs_sb_info *sbi, block_t blkaddr)
-{
-	int err = -EOPNOTSUPP;
-
-	if (test_opt(sbi, DISCARD)) {
-		struct seg_entry *se = get_seg_entry(sbi,
-				GET_SEGNO(sbi, blkaddr));
-		unsigned int offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
-
-		if (f2fs_test_bit(offset, se->discard_map))
-			return false;
-
-		err = f2fs_issue_discard(sbi, blkaddr, 1);
-	}
-
-	if (err) {
-		update_meta_page(sbi, NULL, blkaddr);
-		return true;
-	}
-	return false;
-}
-
 static void __add_discard_entry(struct f2fs_sb_info *sbi,
 		struct cp_control *cpc, struct seg_entry *se,
 		unsigned int start, unsigned int end)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 29e3cf4..7fda940 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1812,6 +1812,9 @@ try_onemore:
 	if (err)
 		goto free_proc;
 
+	if (!retry)
+		goto skip_recovery;
+
 	/* recover fsynced data */
 	if (!test_opt(sbi, DISABLE_ROLL_FORWARD)) {
 		/*
@@ -1844,7 +1847,7 @@ try_onemore:
 			goto free_kobj;
 		}
 	}
-
+skip_recovery:
 	/* recover_fsync_data() cleared this already */
 	clear_sbi_flag(sbi, SBI_POR_DOING);
 
-- 
2.8.3

[PATCH 2/2] f2fs: put directory inodes before checkpoint in roll-forward recovery

[Jaegeuk Kim]

Before checkpoint, we'd be better drop any inodes.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/recovery.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index 2b8a56d..509273a 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -630,6 +630,9 @@ out:
 		set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
 	mutex_unlock(&sbi->cp_mutex);
 
+	/* let's drop all the directory inodes for clean checkpoint */
+	destroy_fsync_dnodes(&dir_list);
+
 	if (!err && need_writecp) {
 		struct cp_control cpc = {
 			.reason = CP_RECOVERY,
@@ -637,7 +640,6 @@ out:
 		err = write_checkpoint(sbi, &cpc);
 	}
 
-	destroy_fsync_dnodes(&dir_list);
 	kmem_cache_destroy(fsync_entry_slab);
 	return ret ? ret: err;
 }
-- 
2.8.3

Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery

[Chao Yu]

Hi Jaegeuk,

On 2016/9/20 10:55, Jaegeuk Kim wrote:
> Previously, we used cp_version only to detect recoverable dnodes.
> In order to avoid same garbage cp_version, we needed to truncate the next
> dnode during checkpoint, resulting in additional discard or data write.
> If we can distinguish this by using crc in addition to cp_version, we can
> remove this overhead.
> 
> There is backward compatibility concern where it changes node_footer layout.
> But, it only affects the direct nodes written after the last checkpoint.
> We simply expect that user would change kernel versions back and forth after
> stable checkpoint.

With it, tests/generic/050 of fstest will fail:

     setting device read-only
     mounting filesystem that needs recovery on a read-only device:
     mount: SCRATCH_DEV is write-protected, mounting read-only
    -mount: cannot mount SCRATCH_DEV read-only
     unmounting read-only filesystem
    -umount: SCRATCH_DEV: not mounted
     mounting filesystem with -o norecovery on a read-only device:

Could you have a look at it?

Thanks,

Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery

[Jaegeuk Kim]

On Tue, Sep 20, 2016 at 11:48:24PM +0800, Chao Yu wrote:
> Hi Jaegeuk,
> 
> On 2016/9/20 10:55, Jaegeuk Kim wrote:
> > Previously, we used cp_version only to detect recoverable dnodes.
> > In order to avoid same garbage cp_version, we needed to truncate the next
> > dnode during checkpoint, resulting in additional discard or data write.
> > If we can distinguish this by using crc in addition to cp_version, we can
> > remove this overhead.
> > 
> > There is backward compatibility concern where it changes node_footer layout.
> > But, it only affects the direct nodes written after the last checkpoint.
> > We simply expect that user would change kernel versions back and forth after
> > stable checkpoint.
> 
> With it, tests/generic/050 of fstest will fail:
> 
>      setting device read-only
>      mounting filesystem that needs recovery on a read-only device:
>      mount: SCRATCH_DEV is write-protected, mounting read-only
>     -mount: cannot mount SCRATCH_DEV read-only
>      unmounting read-only filesystem
>     -umount: SCRATCH_DEV: not mounted
>      mounting filesystem with -o norecovery on a read-only device:
> 
> Could you have a look at it?

Confirmed. There was a bug in the retrial path of fill_super().
I'm testing with this patch without any failure.

Thanks,

>From 2536ed279d3675549c5efe5747bf56b08a4e7070 Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Mon, 19 Sep 2016 17:55:10 -0700
Subject: [PATCH] f2fs: use crc and cp version to determine roll-forward
 recovery

Previously, we used cp_version only to detect recoverable dnodes.
In order to avoid same garbage cp_version, we needed to truncate the next
dnode during checkpoint, resulting in additional discard or data write.
If we can distinguish this by using crc in addition to cp_version, we can
remove this overhead.

There is backward compatibility concern where it changes node_footer layout.
But, it only affects the direct nodes written after the last checkpoint.
We simply expect that user would change kernel versions back and forth after
stable checkpoint.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/checkpoint.c | 18 -------------
 fs/f2fs/f2fs.h       |  1 -
 fs/f2fs/node.h       | 73 ++++++++++++++++++++++++++++++++--------------------
 fs/f2fs/recovery.c   | 36 +++++---------------------
 fs/f2fs/segment.c    | 22 ----------------
 fs/f2fs/super.c      |  5 +++-
 6 files changed, 55 insertions(+), 100 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index df56a43..6ecc5b8 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -992,7 +992,6 @@ static void wait_on_all_pages_writeback(struct f2fs_sb_info *sbi)
 static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
-	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num;
 	nid_t last_nid = nm_i->next_scan_nid;
@@ -1001,19 +1000,10 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	__u32 crc32 = 0;
 	int i;
 	int cp_payload_blks = __cp_payload(sbi);
-	block_t discard_blk = NEXT_FREE_BLKADDR(sbi, curseg);
-	bool invalidate = false;
 	struct super_block *sb = sbi->sb;
 	struct curseg_info *seg_i = CURSEG_I(sbi, CURSEG_HOT_NODE);
 	u64 kbytes_written;
 
-	/*
-	 * This avoids to conduct wrong roll-forward operations and uses
-	 * metapages, so should be called prior to sync_meta_pages below.
-	 */
-	if (!test_opt(sbi, LFS) && discard_next_dnode(sbi, discard_blk))
-		invalidate = true;
-
 	/* Flush all the NAT/SIT pages */
 	while (get_pages(sbi, F2FS_DIRTY_META)) {
 		sync_meta_pages(sbi, META, LONG_MAX);
@@ -1154,14 +1144,6 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	/* wait for previous submitted meta pages writeback */
 	wait_on_all_pages_writeback(sbi);
 
-	/*
-	 * invalidate meta page which is used temporarily for zeroing out
-	 * block at the end of warm node chain.
-	 */
-	if (invalidate)
-		invalidate_mapping_pages(META_MAPPING(sbi), discard_blk,
-								discard_blk);
-
 	release_ino_entry(sbi, false);
 
 	if (unlikely(f2fs_cp_error(sbi)))
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 132756c..a472191 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2065,7 +2065,6 @@ void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t);
 void f2fs_wait_all_discard_bio(struct f2fs_sb_info *);
 void clear_prefree_segments(struct f2fs_sb_info *, struct cp_control *);
 void release_discard_addrs(struct f2fs_sb_info *);
-bool discard_next_dnode(struct f2fs_sb_info *, block_t);
 int npages_for_summary_flush(struct f2fs_sb_info *, bool);
 void allocate_new_segments(struct f2fs_sb_info *);
 int f2fs_trim_fs(struct f2fs_sb_info *, struct fstrim_range *);
diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index fc76845..e8114f9 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -229,6 +229,37 @@ static inline void set_to_next_nat(struct f2fs_nm_info *nm_i, nid_t start_nid)
 	f2fs_change_bit(block_off, nm_i->nat_bitmap);
 }
 
+static inline nid_t ino_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.ino);
+}
+
+static inline nid_t nid_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.nid);
+}
+
+static inline unsigned int ofs_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	unsigned flag = le32_to_cpu(rn->footer.flag);
+	return flag >> OFFSET_BIT_SHIFT;
+}
+
+static inline __u64 cpver_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le64_to_cpu(rn->footer.cp_ver);
+}
+
+static inline block_t next_blkaddr_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.next_blkaddr);
+}
+
 static inline void fill_node_footer(struct page *page, nid_t nid,
 				nid_t ino, unsigned int ofs, bool reset)
 {
@@ -259,40 +290,26 @@ static inline void fill_node_footer_blkaddr(struct page *page, block_t blkaddr)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
 	struct f2fs_node *rn = F2FS_NODE(page);
+	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
+	__u64 cp_ver = le64_to_cpu(ckpt->checkpoint_ver);
+	__u64 crc;
 
-	rn->footer.cp_ver = ckpt->checkpoint_ver;
+	crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset)));
+	cp_ver |= (crc << 32);
+	rn->footer.cp_ver = cpu_to_le64(cp_ver);
 	rn->footer.next_blkaddr = cpu_to_le32(blkaddr);
 }
 
-static inline nid_t ino_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le32_to_cpu(rn->footer.ino);
-}
-
-static inline nid_t nid_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le32_to_cpu(rn->footer.nid);
-}
-
-static inline unsigned int ofs_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	unsigned flag = le32_to_cpu(rn->footer.flag);
-	return flag >> OFFSET_BIT_SHIFT;
-}
-
-static inline unsigned long long cpver_of_node(struct page *node_page)
+static inline bool is_recoverable_dnode(struct page *page)
 {
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le64_to_cpu(rn->footer.cp_ver);
-}
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
+	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
+	__u64 cp_ver = cur_cp_version(ckpt);
+	__u64 crc;
 
-static inline block_t next_blkaddr_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le32_to_cpu(rn->footer.next_blkaddr);
+	crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset)));
+	cp_ver |= (crc << 32);
+	return cpu_to_le64(cp_ver) == cpver_of_node(page);
 }
 
 /*
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index ad748e5..2b8a56d 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -224,7 +224,6 @@ static bool is_same_inode(struct inode *inode, struct page *ipage)
 
 static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
 {
-	unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
 	struct curseg_info *curseg;
 	struct page *page = NULL;
 	block_t blkaddr;
@@ -242,7 +241,7 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
 
 		page = get_tmp_page(sbi, blkaddr);
 
-		if (cp_ver != cpver_of_node(page))
+		if (!is_recoverable_dnode(page))
 			break;
 
 		if (!is_fsync_dnode(page))
@@ -516,7 +515,6 @@ out:
 static int recover_data(struct f2fs_sb_info *sbi, struct list_head *inode_list,
 						struct list_head *dir_list)
 {
-	unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
 	struct curseg_info *curseg;
 	struct page *page = NULL;
 	int err = 0;
@@ -536,7 +534,7 @@ static int recover_data(struct f2fs_sb_info *sbi, struct list_head *inode_list,
 
 		page = get_tmp_page(sbi, blkaddr);
 
-		if (cp_ver != cpver_of_node(page)) {
+		if (!is_recoverable_dnode(page)) {
 			f2fs_put_page(page, 1);
 			break;
 		}
@@ -628,37 +626,15 @@ out:
 	}
 
 	clear_sbi_flag(sbi, SBI_POR_DOING);
-	if (err) {
-		bool invalidate = false;
-
-		if (test_opt(sbi, LFS)) {
-			update_meta_page(sbi, NULL, blkaddr);
-			invalidate = true;
-		} else if (discard_next_dnode(sbi, blkaddr)) {
-			invalidate = true;
-		}
-
-		f2fs_wait_all_discard_bio(sbi);
-
-		/* Flush all the NAT/SIT pages */
-		while (get_pages(sbi, F2FS_DIRTY_META))
-			sync_meta_pages(sbi, META, LONG_MAX);
-
-		/* invalidate temporary meta page */
-		if (invalidate)
-			invalidate_mapping_pages(META_MAPPING(sbi),
-							blkaddr, blkaddr);
-
+	if (err)
 		set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
-		mutex_unlock(&sbi->cp_mutex);
-	} else if (need_writecp) {
+	mutex_unlock(&sbi->cp_mutex);
+
+	if (!err && need_writecp) {
 		struct cp_control cpc = {
 			.reason = CP_RECOVERY,
 		};
-		mutex_unlock(&sbi->cp_mutex);
 		err = write_checkpoint(sbi, &cpc);
-	} else {
-		mutex_unlock(&sbi->cp_mutex);
 	}
 
 	destroy_fsync_dnodes(&dir_list);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c4d0472..2d23d7b 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -669,28 +669,6 @@ static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
 	return __f2fs_issue_discard_async(sbi, start, len, GFP_NOFS, 0);
 }
 
-bool discard_next_dnode(struct f2fs_sb_info *sbi, block_t blkaddr)
-{
-	int err = -EOPNOTSUPP;
-
-	if (test_opt(sbi, DISCARD)) {
-		struct seg_entry *se = get_seg_entry(sbi,
-				GET_SEGNO(sbi, blkaddr));
-		unsigned int offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
-
-		if (f2fs_test_bit(offset, se->discard_map))
-			return false;
-
-		err = f2fs_issue_discard(sbi, blkaddr, 1);
-	}
-
-	if (err) {
-		update_meta_page(sbi, NULL, blkaddr);
-		return true;
-	}
-	return false;
-}
-
 static void __add_discard_entry(struct f2fs_sb_info *sbi,
 		struct cp_control *cpc, struct seg_entry *se,
 		unsigned int start, unsigned int end)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 29e3cf4..9649b79 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1827,6 +1827,9 @@ try_onemore:
 		if (need_fsck)
 			set_sbi_flag(sbi, SBI_NEED_FSCK);
 
+		if (!retry)
+			goto skip_recovery;
+
 		err = recover_fsync_data(sbi, false);
 		if (err < 0) {
 			need_fsck = true;
@@ -1844,7 +1847,7 @@ try_onemore:
 			goto free_kobj;
 		}
 	}
-
+skip_recovery:
 	/* recover_fsync_data() cleared this already */
 	clear_sbi_flag(sbi, SBI_POR_DOING);
 
-- 
2.8.3

Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery

[Chao Yu]

On 2016/9/21 8:45, Jaegeuk Kim wrote:
> @@ -259,40 +290,26 @@ static inline void fill_node_footer_blkaddr(struct page *page, block_t blkaddr)
>  {
>  	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
>  	struct f2fs_node *rn = F2FS_NODE(page);
> +	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
> +	__u64 cp_ver = le64_to_cpu(ckpt->checkpoint_ver);
> +	__u64 crc;
>  
> -	rn->footer.cp_ver = ckpt->checkpoint_ver;
> +	crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset)));
> +	cp_ver |= (crc << 32);

How about using '^=' here?

> +	rn->footer.cp_ver = cpu_to_le64(cp_ver);
>  	rn->footer.next_blkaddr = cpu_to_le32(blkaddr);
>  }
>  
> -static inline nid_t ino_of_node(struct page *node_page)
> -{
> -	struct f2fs_node *rn = F2FS_NODE(node_page);
> -	return le32_to_cpu(rn->footer.ino);
> -}
> -
> -static inline nid_t nid_of_node(struct page *node_page)
> -{
> -	struct f2fs_node *rn = F2FS_NODE(node_page);
> -	return le32_to_cpu(rn->footer.nid);
> -}
> -
> -static inline unsigned int ofs_of_node(struct page *node_page)
> -{
> -	struct f2fs_node *rn = F2FS_NODE(node_page);
> -	unsigned flag = le32_to_cpu(rn->footer.flag);
> -	return flag >> OFFSET_BIT_SHIFT;
> -}
> -
> -static inline unsigned long long cpver_of_node(struct page *node_page)
> +static inline bool is_recoverable_dnode(struct page *page)
>  {
> -	struct f2fs_node *rn = F2FS_NODE(node_page);
> -	return le64_to_cpu(rn->footer.cp_ver);
> -}
> +	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
> +	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
> +	__u64 cp_ver = cur_cp_version(ckpt);
> +	__u64 crc;
>  
> -static inline block_t next_blkaddr_of_node(struct page *node_page)
> -{
> -	struct f2fs_node *rn = F2FS_NODE(node_page);
> -	return le32_to_cpu(rn->footer.next_blkaddr);
> +	crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset)));
> +	cp_ver |= (crc << 32);
> +	return cpu_to_le64(cp_ver) == cpver_of_node(page);
>  }

cpu_to_le64(cp_ver) == cpver_of_node(page) ^ (crc << 32)

Thanks,

Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery

[Jaegeuk Kim]

On Sat, Sep 24, 2016 at 02:00:41PM +0800, Chao Yu wrote:
> On 2016/9/21 8:45, Jaegeuk Kim wrote:
> > @@ -259,40 +290,26 @@ static inline void fill_node_footer_blkaddr(struct page *page, block_t blkaddr)
> >  {
> >  	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
> >  	struct f2fs_node *rn = F2FS_NODE(page);
> > +	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
> > +	__u64 cp_ver = le64_to_cpu(ckpt->checkpoint_ver);
> > +	__u64 crc;
> >  
> > -	rn->footer.cp_ver = ckpt->checkpoint_ver;
> > +	crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset)));
> > +	cp_ver |= (crc << 32);
> 
> How about using '^=' here?

The crc is already random enough, but has 32bits only.
The cp_ver is not easy to use over 32bits, so we don't need to keep the other
32bits untouched in most of life.

Thanks,

> 
> > +	rn->footer.cp_ver = cpu_to_le64(cp_ver);
> >  	rn->footer.next_blkaddr = cpu_to_le32(blkaddr);
> >  }
> >  
> > -static inline nid_t ino_of_node(struct page *node_page)
> > -{
> > -	struct f2fs_node *rn = F2FS_NODE(node_page);
> > -	return le32_to_cpu(rn->footer.ino);
> > -}
> > -
> > -static inline nid_t nid_of_node(struct page *node_page)
> > -{
> > -	struct f2fs_node *rn = F2FS_NODE(node_page);
> > -	return le32_to_cpu(rn->footer.nid);
> > -}
> > -
> > -static inline unsigned int ofs_of_node(struct page *node_page)
> > -{
> > -	struct f2fs_node *rn = F2FS_NODE(node_page);
> > -	unsigned flag = le32_to_cpu(rn->footer.flag);
> > -	return flag >> OFFSET_BIT_SHIFT;
> > -}
> > -
> > -static inline unsigned long long cpver_of_node(struct page *node_page)
> > +static inline bool is_recoverable_dnode(struct page *page)
> >  {
> > -	struct f2fs_node *rn = F2FS_NODE(node_page);
> > -	return le64_to_cpu(rn->footer.cp_ver);
> > -}
> > +	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
> > +	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
> > +	__u64 cp_ver = cur_cp_version(ckpt);
> > +	__u64 crc;
> >  
> > -static inline block_t next_blkaddr_of_node(struct page *node_page)
> > -{
> > -	struct f2fs_node *rn = F2FS_NODE(node_page);
> > -	return le32_to_cpu(rn->footer.next_blkaddr);
> > +	crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset)));
> > +	cp_ver |= (crc << 32);
> > +	return cpu_to_le64(cp_ver) == cpver_of_node(page);
> >  }
> 
> cpu_to_le64(cp_ver) == cpver_of_node(page) ^ (crc << 32)
> 
> Thanks,

Re: [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery

[Chao Yu]

On 2016/9/20 10:55, Jaegeuk Kim wrote:
> Previously, we used cp_version only to detect recoverable dnodes.
> In order to avoid same garbage cp_version, we needed to truncate the next
> dnode during checkpoint, resulting in additional discard or data write.
> If we can distinguish this by using crc in addition to cp_version, we can
> remove this overhead.
> 
> There is backward compatibility concern where it changes node_footer layout.
> But, it only affects the direct nodes written after the last checkpoint.
> We simply expect that user would change kernel versions back and forth after
> stable checkpoint.

Seems with new released v4.8 f2fs, old image with recoverable data could be
mounted successfully, but meanwhile all fsynced data which needs to be recovered
will be lost w/o any hints?

Could we release a new version mkfs paired with new kernel module, so we can tag
image as a new layout one, then new kernel module can recognize the image layout
and adjust version suited comparing method with old or new image?

Thanks,

Re: [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery

[Jaegeuk Kim]

On Thu, Sep 29, 2016 at 08:01:32PM +0800, Chao Yu wrote:
> On 2016/9/20 10:55, Jaegeuk Kim wrote:
> > Previously, we used cp_version only to detect recoverable dnodes.
> > In order to avoid same garbage cp_version, we needed to truncate the next
> > dnode during checkpoint, resulting in additional discard or data write.
> > If we can distinguish this by using crc in addition to cp_version, we can
> > remove this overhead.
> > 
> > There is backward compatibility concern where it changes node_footer layout.
> > But, it only affects the direct nodes written after the last checkpoint.
> > We simply expect that user would change kernel versions back and forth after
> > stable checkpoint.
> 
> Seems with new released v4.8 f2fs, old image with recoverable data could be
> mounted successfully, but meanwhile all fsynced data which needs to be recovered
> will be lost w/o any hints?
> 
> Could we release a new version mkfs paired with new kernel module, so we can tag
> image as a new layout one, then new kernel module can recognize the image layout
> and adjust version suited comparing method with old or new image?

Hmm, how about adding a checkpoint flag like CP_CRC_RECOVERY_FLAG?
Then, we can proceed crc|cp_ver, if the last checkpoint has this flag.

Any thought?

> 
> Thanks,
> 
> 

Re: [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery

[Chao Yu]

On 2016/9/30 8:53, Jaegeuk Kim wrote:
> On Thu, Sep 29, 2016 at 08:01:32PM +0800, Chao Yu wrote:
>> On 2016/9/20 10:55, Jaegeuk Kim wrote:
>>> Previously, we used cp_version only to detect recoverable dnodes.
>>> In order to avoid same garbage cp_version, we needed to truncate the next
>>> dnode during checkpoint, resulting in additional discard or data write.
>>> If we can distinguish this by using crc in addition to cp_version, we can
>>> remove this overhead.
>>>
>>> There is backward compatibility concern where it changes node_footer layout.
>>> But, it only affects the direct nodes written after the last checkpoint.
>>> We simply expect that user would change kernel versions back and forth after
>>> stable checkpoint.
>>
>> Seems with new released v4.8 f2fs, old image with recoverable data could be
>> mounted successfully, but meanwhile all fsynced data which needs to be recovered
>> will be lost w/o any hints?
>>
>> Could we release a new version mkfs paired with new kernel module, so we can tag
>> image as a new layout one, then new kernel module can recognize the image layout
>> and adjust version suited comparing method with old or new image?
> 
> Hmm, how about adding a checkpoint flag like CP_CRC_RECOVERY_FLAG?
> Then, we can proceed crc|cp_ver, if the last checkpoint has this flag.
> 
> Any thought?

Ah, that's better. :)

Thanks,

> 
>>
>> Thanks,
>>
>>
> 
> .
> 

Re: [PATCH 1/2 v2] f2fs: use crc and cp version to determine roll-forward recovery

[Jaegeuk Kim]

Previously, we used cp_version only to detect recoverable dnodes.
In order to avoid same garbage cp_version, we needed to truncate the next
dnode during checkpoint, resulting in additional discard or data write.
If we can distinguish this by using crc in addition to cp_version, we can
remove this overhead.

There is backward compatibility concern where it changes node_footer layout.
So, this patch introduces a new checkpoint flag, CP_CRC_RECOVERY_FLAG, to
detect new layout. New layout will be activated only when this flag is set.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/checkpoint.c    | 21 ++------------
 fs/f2fs/f2fs.h          |  1 -
 fs/f2fs/node.h          | 77 +++++++++++++++++++++++++++++++------------------
 fs/f2fs/recovery.c      | 36 ++++-------------------
 fs/f2fs/segment.c       | 22 --------------
 fs/f2fs/super.c         |  5 +++-
 include/linux/f2fs_fs.h |  1 +
 7 files changed, 63 insertions(+), 100 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index df56a43..9c6439b 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -992,7 +992,6 @@ static void wait_on_all_pages_writeback(struct f2fs_sb_info *sbi)
 static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
-	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
 	unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num;
 	nid_t last_nid = nm_i->next_scan_nid;
@@ -1001,19 +1000,10 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	__u32 crc32 = 0;
 	int i;
 	int cp_payload_blks = __cp_payload(sbi);
-	block_t discard_blk = NEXT_FREE_BLKADDR(sbi, curseg);
-	bool invalidate = false;
 	struct super_block *sb = sbi->sb;
 	struct curseg_info *seg_i = CURSEG_I(sbi, CURSEG_HOT_NODE);
 	u64 kbytes_written;
 
-	/*
-	 * This avoids to conduct wrong roll-forward operations and uses
-	 * metapages, so should be called prior to sync_meta_pages below.
-	 */
-	if (!test_opt(sbi, LFS) && discard_next_dnode(sbi, discard_blk))
-		invalidate = true;
-
 	/* Flush all the NAT/SIT pages */
 	while (get_pages(sbi, F2FS_DIRTY_META)) {
 		sync_meta_pages(sbi, META, LONG_MAX);
@@ -1089,6 +1079,9 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
 		set_ckpt_flags(ckpt, CP_FSCK_FLAG);
 
+	/* set this flag to activate crc|cp_ver for recovery */
+	set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG);
+
 	/* update SIT/NAT bitmap */
 	get_sit_bitmap(sbi, __bitmap_ptr(sbi, SIT_BITMAP));
 	get_nat_bitmap(sbi, __bitmap_ptr(sbi, NAT_BITMAP));
@@ -1154,14 +1147,6 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	/* wait for previous submitted meta pages writeback */
 	wait_on_all_pages_writeback(sbi);
 
-	/*
-	 * invalidate meta page which is used temporarily for zeroing out
-	 * block at the end of warm node chain.
-	 */
-	if (invalidate)
-		invalidate_mapping_pages(META_MAPPING(sbi), discard_blk,
-								discard_blk);
-
 	release_ino_entry(sbi, false);
 
 	if (unlikely(f2fs_cp_error(sbi)))
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index b39fdcd..cda8e6f 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2045,7 +2045,6 @@ void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t);
 void f2fs_wait_all_discard_bio(struct f2fs_sb_info *);
 void clear_prefree_segments(struct f2fs_sb_info *, struct cp_control *);
 void release_discard_addrs(struct f2fs_sb_info *);
-bool discard_next_dnode(struct f2fs_sb_info *, block_t);
 int npages_for_summary_flush(struct f2fs_sb_info *, bool);
 void allocate_new_segments(struct f2fs_sb_info *);
 int f2fs_trim_fs(struct f2fs_sb_info *, struct fstrim_range *);
diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index fc76845..e8ca64a 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -229,6 +229,37 @@ static inline void set_to_next_nat(struct f2fs_nm_info *nm_i, nid_t start_nid)
 	f2fs_change_bit(block_off, nm_i->nat_bitmap);
 }
 
+static inline nid_t ino_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.ino);
+}
+
+static inline nid_t nid_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.nid);
+}
+
+static inline unsigned int ofs_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	unsigned flag = le32_to_cpu(rn->footer.flag);
+	return flag >> OFFSET_BIT_SHIFT;
+}
+
+static inline __u64 cpver_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le64_to_cpu(rn->footer.cp_ver);
+}
+
+static inline block_t next_blkaddr_of_node(struct page *node_page)
+{
+	struct f2fs_node *rn = F2FS_NODE(node_page);
+	return le32_to_cpu(rn->footer.next_blkaddr);
+}
+
 static inline void fill_node_footer(struct page *page, nid_t nid,
 				nid_t ino, unsigned int ofs, bool reset)
 {
@@ -259,40 +290,30 @@ static inline void fill_node_footer_blkaddr(struct page *page, block_t blkaddr)
 {
 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
 	struct f2fs_node *rn = F2FS_NODE(page);
+	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
+	__u64 cp_ver = le64_to_cpu(ckpt->checkpoint_ver);
 
-	rn->footer.cp_ver = ckpt->checkpoint_ver;
+	if (is_set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG)) {
+		__u64 crc = le32_to_cpu(*((__le32 *)
+				((unsigned char *)ckpt + crc_offset)));
+		cp_ver |= (crc << 32);
+	}
+	rn->footer.cp_ver = cpu_to_le64(cp_ver);
 	rn->footer.next_blkaddr = cpu_to_le32(blkaddr);
 }
 
-static inline nid_t ino_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le32_to_cpu(rn->footer.ino);
-}
-
-static inline nid_t nid_of_node(struct page *node_page)
+static inline bool is_recoverable_dnode(struct page *page)
 {
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le32_to_cpu(rn->footer.nid);
-}
-
-static inline unsigned int ofs_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	unsigned flag = le32_to_cpu(rn->footer.flag);
-	return flag >> OFFSET_BIT_SHIFT;
-}
-
-static inline unsigned long long cpver_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le64_to_cpu(rn->footer.cp_ver);
-}
+	struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page));
+	size_t crc_offset = le32_to_cpu(ckpt->checksum_offset);
+	__u64 cp_ver = cur_cp_version(ckpt);
 
-static inline block_t next_blkaddr_of_node(struct page *node_page)
-{
-	struct f2fs_node *rn = F2FS_NODE(node_page);
-	return le32_to_cpu(rn->footer.next_blkaddr);
+	if (is_set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG)) {
+		__u64 crc = le32_to_cpu(*((__le32 *)
+				((unsigned char *)ckpt + crc_offset)));
+		cp_ver |= (crc << 32);
+	}
+	return cpu_to_le64(cp_ver) == cpver_of_node(page);
 }
 
 /*
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index ad748e5..2b8a56d 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -224,7 +224,6 @@ static bool is_same_inode(struct inode *inode, struct page *ipage)
 
 static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
 {
-	unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
 	struct curseg_info *curseg;
 	struct page *page = NULL;
 	block_t blkaddr;
@@ -242,7 +241,7 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
 
 		page = get_tmp_page(sbi, blkaddr);
 
-		if (cp_ver != cpver_of_node(page))
+		if (!is_recoverable_dnode(page))
 			break;
 
 		if (!is_fsync_dnode(page))
@@ -516,7 +515,6 @@ out:
 static int recover_data(struct f2fs_sb_info *sbi, struct list_head *inode_list,
 						struct list_head *dir_list)
 {
-	unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
 	struct curseg_info *curseg;
 	struct page *page = NULL;
 	int err = 0;
@@ -536,7 +534,7 @@ static int recover_data(struct f2fs_sb_info *sbi, struct list_head *inode_list,
 
 		page = get_tmp_page(sbi, blkaddr);
 
-		if (cp_ver != cpver_of_node(page)) {
+		if (!is_recoverable_dnode(page)) {
 			f2fs_put_page(page, 1);
 			break;
 		}
@@ -628,37 +626,15 @@ out:
 	}
 
 	clear_sbi_flag(sbi, SBI_POR_DOING);
-	if (err) {
-		bool invalidate = false;
-
-		if (test_opt(sbi, LFS)) {
-			update_meta_page(sbi, NULL, blkaddr);
-			invalidate = true;
-		} else if (discard_next_dnode(sbi, blkaddr)) {
-			invalidate = true;
-		}
-
-		f2fs_wait_all_discard_bio(sbi);
-
-		/* Flush all the NAT/SIT pages */
-		while (get_pages(sbi, F2FS_DIRTY_META))
-			sync_meta_pages(sbi, META, LONG_MAX);
-
-		/* invalidate temporary meta page */
-		if (invalidate)
-			invalidate_mapping_pages(META_MAPPING(sbi),
-							blkaddr, blkaddr);
-
+	if (err)
 		set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
-		mutex_unlock(&sbi->cp_mutex);
-	} else if (need_writecp) {
+	mutex_unlock(&sbi->cp_mutex);
+
+	if (!err && need_writecp) {
 		struct cp_control cpc = {
 			.reason = CP_RECOVERY,
 		};
-		mutex_unlock(&sbi->cp_mutex);
 		err = write_checkpoint(sbi, &cpc);
-	} else {
-		mutex_unlock(&sbi->cp_mutex);
 	}
 
 	destroy_fsync_dnodes(&dir_list);
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c4d0472..2d23d7b 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -669,28 +669,6 @@ static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
 	return __f2fs_issue_discard_async(sbi, start, len, GFP_NOFS, 0);
 }
 
-bool discard_next_dnode(struct f2fs_sb_info *sbi, block_t blkaddr)
-{
-	int err = -EOPNOTSUPP;
-
-	if (test_opt(sbi, DISCARD)) {
-		struct seg_entry *se = get_seg_entry(sbi,
-				GET_SEGNO(sbi, blkaddr));
-		unsigned int offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
-
-		if (f2fs_test_bit(offset, se->discard_map))
-			return false;
-
-		err = f2fs_issue_discard(sbi, blkaddr, 1);
-	}
-
-	if (err) {
-		update_meta_page(sbi, NULL, blkaddr);
-		return true;
-	}
-	return false;
-}
-
 static void __add_discard_entry(struct f2fs_sb_info *sbi,
 		struct cp_control *cpc, struct seg_entry *se,
 		unsigned int start, unsigned int end)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 29e3cf4..9649b79 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1827,6 +1827,9 @@ try_onemore:
 		if (need_fsck)
 			set_sbi_flag(sbi, SBI_NEED_FSCK);
 
+		if (!retry)
+			goto skip_recovery;
+
 		err = recover_fsync_data(sbi, false);
 		if (err < 0) {
 			need_fsck = true;
@@ -1844,7 +1847,7 @@ try_onemore:
 			goto free_kobj;
 		}
 	}
-
+skip_recovery:
 	/* recover_fsync_data() cleared this already */
 	clear_sbi_flag(sbi, SBI_POR_DOING);
 
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index 4c02c65..422630b 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -100,6 +100,7 @@ struct f2fs_super_block {
 /*
  * For checkpoint
  */
+#define CP_CRC_RECOVERY_FLAG	0x00000040
 #define CP_FASTBOOT_FLAG	0x00000020
 #define CP_FSCK_FLAG		0x00000010
 #define CP_ERROR_FLAG		0x00000008
-- 
2.8.3

Re: [f2fs-dev] [PATCH 1/2 v2] f2fs: use crc and cp version to determine roll-forward recovery

[Chao Yu]

On 2016/10/1 1:10, Jaegeuk Kim wrote:
> @@ -1089,6 +1079,9 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
>  	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
>  		set_ckpt_flags(ckpt, CP_FSCK_FLAG);
>  
> +	/* set this flag to activate crc|cp_ver for recovery */
> +	set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG);

Should let new introduced spinlock cover the flag updating in ("f2fs: introduce
cp_lock to protect updating of ckpt_flags").

Thanks,

Re: [f2fs-dev] [PATCH 1/2 v2] f2fs: use crc and cp version to determine roll-forward recovery

[Jaegeuk Kim]

On Sat, Oct 01, 2016 at 08:26:20AM +0800, Chao Yu wrote:
> On 2016/10/1 1:10, Jaegeuk Kim wrote:
> > @@ -1089,6 +1079,9 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
> >  	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
> >  		set_ckpt_flags(ckpt, CP_FSCK_FLAG);
> >  
> > +	/* set this flag to activate crc|cp_ver for recovery */
> > +	set_ckpt_flags(ckpt, CP_CRC_RECOVERY_FLAG);
> 
> Should let new introduced spinlock cover the flag updating in ("f2fs: introduce
> cp_lock to protect updating of ckpt_flags").

Fixed.

http://git.kernel.org/cgit/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev-test&id=aaec2b1d18792a5f27b69ff37f34f43f89f5aa3b

Thank you. :)

> 
> Thanks,