[PATCH v2 4/6] f2fs: introduce cp_lock to protect updating of ckpt_flags

[Chao Yu]

This patch introduces spinlock to protect updating process of ckpt_flags
field in struct f2fs_checkpoint, it avoids incorrectly updating in race
condition.

Signed-off-by: Chao Yu 
---
 fs/f2fs/checkpoint.c | 28 
 fs/f2fs/f2fs.h   | 37 +
 fs/f2fs/recovery.c   |  2 +-
 fs/f2fs/segment.c|  4 ++--
 fs/f2fs/super.c  |  5 +++--
 5 files changed, 51 insertions(+), 25 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index a366521..bc93afd 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -28,7 +28,7 @@ struct kmem_cache *inode_entry_slab;
 
 void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io)
 {
-   set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
+   set_ckpt_flags(sbi, CP_ERROR_FLAG);
sbi->sb->s_flags |= MS_RDONLY;
if (!end_io)
f2fs_flush_merged_bios(sbi);
@@ -574,7 +574,7 @@ int recover_orphan_inodes(struct f2fs_sb_info *sbi)
block_t start_blk, orphan_blocks, i, j;
int err;
 
-   if (!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG))
+   if (!is_set_ckpt_flags(sbi, CP_ORPHAN_PRESENT_FLAG))
return 0;
 
start_blk = __start_cp_addr(sbi) + 1 + __cp_payload(sbi);
@@ -598,7 +598,7 @@ int recover_orphan_inodes(struct f2fs_sb_info *sbi)
f2fs_put_page(page, 1);
}
/* clear Orphan Flag */
-   clear_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG);
+   clear_ckpt_flags(sbi, CP_ORPHAN_PRESENT_FLAG);
return 0;
 }
 
@@ -1056,10 +1056,12 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, 
struct cp_control *cpc)
 
/* 2 cp  + n data seg summary + orphan inode blocks */
data_sum_blocks = npages_for_summary_flush(sbi, false);
+   spin_lock(>cp_lock);
if (data_sum_blocks < NR_CURSEG_DATA_TYPE)
-   set_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
+   __set_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
else
-   clear_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
+   __clear_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
+   spin_unlock(>cp_lock);
 
orphan_blocks = GET_ORPHAN_BLOCKS(orphan_num);
ckpt->cp_pack_start_sum = cpu_to_le32(1 + cp_payload_blks +
@@ -1074,23 +1076,25 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, 
struct cp_control *cpc)
cp_payload_blks + data_sum_blocks +
orphan_blocks);
 
+   spin_lock(>cp_lock);
if (cpc->reason == CP_UMOUNT)
-   set_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
+   __set_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
else
-   clear_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
+   __clear_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
 
if (cpc->reason == CP_FASTBOOT)
-   set_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
+   __set_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
else
-   clear_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
+   __clear_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
 
if (orphan_num)
-   set_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
+   __set_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
else
-   clear_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
+   __clear_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
 
if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
-   set_ckpt_flags(ckpt, CP_FSCK_FLAG);
+   __set_ckpt_flags(ckpt, CP_FSCK_FLAG);
+   spin_unlock(>cp_lock);
 
/* update SIT/NAT bitmap */
get_sit_bitmap(sbi, __bitmap_ptr(sbi, SIT_BITMAP));
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 53da455..7803808 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -817,6 +817,7 @@ struct f2fs_sb_info {
 
/* for checkpoint */
struct f2fs_checkpoint *ckpt;   /* raw checkpoint pointer */
+   spinlock_t cp_lock; /* for flag in ckpt */
struct inode *meta_inode;   /* cache meta blocks */
struct mutex cp_mutex;  /* checkpoint procedure lock */
struct rw_semaphore cp_rwsem;   /* blocking FS operations */
@@ -1084,26 +1085,46 @@ static inline unsigned long long cur_cp_version(struct 
f2fs_checkpoint *cp)
return le64_to_cpu(cp->checkpoint_ver);
 }
 
-static inline bool is_set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int 
f)
+static inline bool is_set_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f)
 {
+   struct f2fs_checkpoint *cp = F2FS_CKPT(sbi);
unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+
return ckpt_flags & f;
 }
 
-static inline void set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
+static inline void __set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
 {
-   unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+   

[PATCH v2 4/6] f2fs: introduce cp_lock to protect updating of ckpt_flags

[Chao Yu]

This patch introduces spinlock to protect updating process of ckpt_flags
field in struct f2fs_checkpoint, it avoids incorrectly updating in race
condition.

Signed-off-by: Chao Yu 
---
 fs/f2fs/checkpoint.c | 28 
 fs/f2fs/f2fs.h   | 37 +
 fs/f2fs/recovery.c   |  2 +-
 fs/f2fs/segment.c|  4 ++--
 fs/f2fs/super.c  |  5 +++--
 5 files changed, 51 insertions(+), 25 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index a366521..bc93afd 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -28,7 +28,7 @@ struct kmem_cache *inode_entry_slab;
 
 void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io)
 {
-   set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
+   set_ckpt_flags(sbi, CP_ERROR_FLAG);
sbi->sb->s_flags |= MS_RDONLY;
if (!end_io)
f2fs_flush_merged_bios(sbi);
@@ -574,7 +574,7 @@ int recover_orphan_inodes(struct f2fs_sb_info *sbi)
block_t start_blk, orphan_blocks, i, j;
int err;
 
-   if (!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG))
+   if (!is_set_ckpt_flags(sbi, CP_ORPHAN_PRESENT_FLAG))
return 0;
 
start_blk = __start_cp_addr(sbi) + 1 + __cp_payload(sbi);
@@ -598,7 +598,7 @@ int recover_orphan_inodes(struct f2fs_sb_info *sbi)
f2fs_put_page(page, 1);
}
/* clear Orphan Flag */
-   clear_ckpt_flags(F2FS_CKPT(sbi), CP_ORPHAN_PRESENT_FLAG);
+   clear_ckpt_flags(sbi, CP_ORPHAN_PRESENT_FLAG);
return 0;
 }
 
@@ -1056,10 +1056,12 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, 
struct cp_control *cpc)
 
/* 2 cp  + n data seg summary + orphan inode blocks */
data_sum_blocks = npages_for_summary_flush(sbi, false);
+   spin_lock(>cp_lock);
if (data_sum_blocks < NR_CURSEG_DATA_TYPE)
-   set_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
+   __set_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
else
-   clear_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
+   __clear_ckpt_flags(ckpt, CP_COMPACT_SUM_FLAG);
+   spin_unlock(>cp_lock);
 
orphan_blocks = GET_ORPHAN_BLOCKS(orphan_num);
ckpt->cp_pack_start_sum = cpu_to_le32(1 + cp_payload_blks +
@@ -1074,23 +1076,25 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, 
struct cp_control *cpc)
cp_payload_blks + data_sum_blocks +
orphan_blocks);
 
+   spin_lock(>cp_lock);
if (cpc->reason == CP_UMOUNT)
-   set_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
+   __set_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
else
-   clear_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
+   __clear_ckpt_flags(ckpt, CP_UMOUNT_FLAG);
 
if (cpc->reason == CP_FASTBOOT)
-   set_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
+   __set_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
else
-   clear_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
+   __clear_ckpt_flags(ckpt, CP_FASTBOOT_FLAG);
 
if (orphan_num)
-   set_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
+   __set_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
else
-   clear_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
+   __clear_ckpt_flags(ckpt, CP_ORPHAN_PRESENT_FLAG);
 
if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
-   set_ckpt_flags(ckpt, CP_FSCK_FLAG);
+   __set_ckpt_flags(ckpt, CP_FSCK_FLAG);
+   spin_unlock(>cp_lock);
 
/* update SIT/NAT bitmap */
get_sit_bitmap(sbi, __bitmap_ptr(sbi, SIT_BITMAP));
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 53da455..7803808 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -817,6 +817,7 @@ struct f2fs_sb_info {
 
/* for checkpoint */
struct f2fs_checkpoint *ckpt;   /* raw checkpoint pointer */
+   spinlock_t cp_lock; /* for flag in ckpt */
struct inode *meta_inode;   /* cache meta blocks */
struct mutex cp_mutex;  /* checkpoint procedure lock */
struct rw_semaphore cp_rwsem;   /* blocking FS operations */
@@ -1084,26 +1085,46 @@ static inline unsigned long long cur_cp_version(struct 
f2fs_checkpoint *cp)
return le64_to_cpu(cp->checkpoint_ver);
 }
 
-static inline bool is_set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int 
f)
+static inline bool is_set_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f)
 {
+   struct f2fs_checkpoint *cp = F2FS_CKPT(sbi);
unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+
return ckpt_flags & f;
 }
 
-static inline void set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
+static inline void __set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
 {
-   unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+   unsigned int ckpt_flags;
+