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Subject[PATCH v2 4/6] f2fs: introduce cp_lock to protect updating of ckpt_flags
Date
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 <yuchao0@huawei.com>
---
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(&sbi->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(&sbi->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(&sbi->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(&sbi->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;
+
+ ckpt_flags = le32_to_cpu(cp->ckpt_flags);
ckpt_flags |= f;
cp->ckpt_flags = cpu_to_le32(ckpt_flags);
}

-static inline void clear_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
+static inline void set_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f)
{
- unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
+ spin_lock(&sbi->cp_lock);
+ __set_ckpt_flags(F2FS_CKPT(sbi), f);
+ spin_unlock(&sbi->cp_lock);
+}
+
+static inline void __clear_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
+{
+ unsigned int ckpt_flags;
+
+ ckpt_flags = le32_to_cpu(cp->ckpt_flags);
ckpt_flags &= (~f);
cp->ckpt_flags = cpu_to_le32(ckpt_flags);
}

+static inline void clear_ckpt_flags(struct f2fs_sb_info *sbi, unsigned int f)
+{
+ spin_lock(&sbi->cp_lock);
+ __clear_ckpt_flags(F2FS_CKPT(sbi), f);
+ spin_unlock(&sbi->cp_lock);
+}
+
static inline bool f2fs_discard_en(struct f2fs_sb_info *sbi)
{
struct request_queue *q = bdev_get_queue(sbi->sb->s_bdev);
@@ -1149,8 +1170,8 @@ static inline bool __remain_node_summaries(int reason)

static inline bool __exist_node_summaries(struct f2fs_sb_info *sbi)
{
- return (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_UMOUNT_FLAG) ||
- is_set_ckpt_flags(F2FS_CKPT(sbi), CP_FASTBOOT_FLAG));
+ return (is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG) ||
+ is_set_ckpt_flags(sbi, CP_FASTBOOT_FLAG));
}

/*
@@ -1852,7 +1873,7 @@ static inline int f2fs_readonly(struct super_block *sb)

static inline bool f2fs_cp_error(struct f2fs_sb_info *sbi)
{
- return is_set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
+ return is_set_ckpt_flags(sbi, CP_ERROR_FLAG);
}

static inline bool is_dot_dotdot(const struct qstr *str)
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index ad748e5..37d99d2 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -649,7 +649,7 @@ out:
invalidate_mapping_pages(META_MAPPING(sbi),
blkaddr, blkaddr);

- set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
+ set_ckpt_flags(sbi, CP_ERROR_FLAG);
mutex_unlock(&sbi->cp_mutex);
} else if (need_writecp) {
struct cp_control cpc = {
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 101b58f..dc68f30 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1825,7 +1825,7 @@ static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
int type = CURSEG_HOT_DATA;
int err;

- if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_COMPACT_SUM_FLAG)) {
+ if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG)) {
int npages = npages_for_summary_flush(sbi, true);

if (npages >= 2)
@@ -1922,7 +1922,7 @@ static void write_normal_summaries(struct f2fs_sb_info *sbi,

void write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
{
- if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_COMPACT_SUM_FLAG))
+ if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG))
write_compacted_summaries(sbi, start_blk);
else
write_normal_summaries(sbi, start_blk, CURSEG_HOT_DATA);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 52575c2..151a0cd 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -736,7 +736,7 @@ static void f2fs_put_super(struct super_block *sb)
* clean checkpoint again.
*/
if (is_sbi_flag_set(sbi, SBI_IS_DIRTY) ||
- !is_set_ckpt_flags(F2FS_CKPT(sbi), CP_UMOUNT_FLAG)) {
+ !is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG)) {
struct cp_control cpc = {
.reason = CP_UMOUNT,
};
@@ -1478,6 +1478,7 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
mutex_init(&sbi->umount_mutex);
mutex_init(&sbi->wio_mutex[NODE]);
mutex_init(&sbi->wio_mutex[DATA]);
+ spin_lock_init(&sbi->cp_lock);

#ifdef CONFIG_F2FS_FS_ENCRYPTION
memcpy(sbi->key_prefix, F2FS_KEY_DESC_PREFIX,
@@ -1819,7 +1820,7 @@ try_onemore:
* previous checkpoint was not done by clean system shutdown.
*/
if (bdev_read_only(sb->s_bdev) &&
- !is_set_ckpt_flags(sbi->ckpt, CP_UMOUNT_FLAG)) {
+ !is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG)) {
err = -EROFS;
goto free_kobj;
}
--
2.8.2.311.gee88674
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