Re: [RFC PATCH v2] f2fs: record need_fsck in super_block

Chao Yu
2022-09-25T13:57:50Z

On 2022/9/23 2:08, Jaegeuk Kim wrote:
> On 09/20, Chao Yu wrote:
>> On 2022/9/20 8:56, Jaegeuk Kim wrote:
>>> On 09/13, Chao Yu wrote:
>>>> Once CP_ERROR_FLAG is set, checkpoint is disallowed to be triggered to
>>>> persist CP_FSCK_FLAG, fsck won't repair the image due to lack of
>>>> CP_FSCK_FLAG.
>>>>
>>>> This patch proposes to persist newly introduced SB_NEED_FSCK flag into
>>>> super block if CP_ERROR_FLAG and SBI_NEED_FSCK is set, later, once fsck
>>>> detect this flag, it can check and repair corrupted image in time.
>>>>
>>>> Signed-off-by: Chao Yu <chao@kernel.org>
>>>> ---
>>>> v2:
>>>> - remove unneeded codes.
>>>> fs/f2fs/checkpoint.c | 6 +++++-
>>>> fs/f2fs/f2fs.h | 1 +
>>>> fs/f2fs/super.c | 26 ++++++++++++++++++++++++++
>>>> include/linux/f2fs_fs.h | 5 ++++-
>>>> 4 files changed, 36 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
>>>> index c3119e4c890c..0836fce40394 100644
>>>> --- a/fs/f2fs/checkpoint.c
>>>> +++ b/fs/f2fs/checkpoint.c
>>>> @@ -30,8 +30,12 @@ void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io)
>>>> {
>>>> f2fs_build_fault_attr(sbi, 0, 0);
>>>> set_ckpt_flags(sbi, CP_ERROR_FLAG);
>>>> - if (!end_io)
>>>> + if (!end_io) {
>>>> f2fs_flush_merged_writes(sbi);
>>>> +
>>>> + if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
>>>> + f2fs_update_sb_flags(sbi, SB_NEED_FSCK);
>>>
>>> Let's think of putting some more context in superblock, if we want to overwrite
>>> it. E.g., a reason to stop checkpoint?
>>
>> Good idea, maybe:
>> Bit Value max number of type
>> [0] need fsck flag 1
>> [1-5] reason to stop checkpoint 32
>> [6-13] reason to fsck 256
>
> How about just keeping the counters of the reasons? (e.g., EIO count which
> stopped checkpoint)
>
> #define MAX_CRASH_REASON 32
> char array[MAX_CRASH_REASON];

Something like this?

---
fs/f2fs/checkpoint.c | 10 +++++++---
fs/f2fs/data.c | 6 ++++--
fs/f2fs/f2fs.h | 4 +++-
fs/f2fs/file.c | 11 ++++++-----
fs/f2fs/gc.c | 6 ++++--
fs/f2fs/inode.c | 3 ++-
fs/f2fs/segment.c | 5 +++--
fs/f2fs/super.c | 25 +++++++++++++++++++++++++
include/linux/f2fs_fs.h | 20 +++++++++++++++++++-
9 files changed, 73 insertions(+), 17 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 308b70812cbd..b14a8e5eca21 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -26,12 +26,16 @@
static struct kmem_cache *ino_entry_slab;
struct kmem_cache *f2fs_inode_entry_slab;

-void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io)
+void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io,
+ unsigned char reason)
{
f2fs_build_fault_attr(sbi, 0, 0);
set_ckpt_flags(sbi, CP_ERROR_FLAG);
- if (!end_io)
+ if (!end_io) {
f2fs_flush_merged_writes(sbi);
+
+ f2fs_update_sb_flags(sbi, reason);
+ }
}

/*
@@ -122,7 +126,7 @@ struct page *f2fs_get_meta_page_retry(struct f2fs_sb_info *sbi, pgoff_t index)
if (PTR_ERR(page) == -EIO &&
++count <= DEFAULT_RETRY_IO_COUNT)
goto retry;
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_META_PAGE);
}
return page;
}
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 4e5be2c1dab9..20c8d835a87b 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -333,7 +333,8 @@ static void f2fs_write_end_io(struct bio *bio)
mempool_free(page, sbi->write_io_dummy);

if (unlikely(bio->bi_status))
- f2fs_stop_checkpoint(sbi, true);
+ f2fs_stop_checkpoint(sbi, true,
+ STOP_CP_REASON_WRITE_FAIL);
continue;
}

@@ -349,7 +350,8 @@ static void f2fs_write_end_io(struct bio *bio)
if (unlikely(bio->bi_status)) {
mapping_set_error(page->mapping, -EIO);
if (type == F2FS_WB_CP_DATA)
- f2fs_stop_checkpoint(sbi, true);
+ f2fs_stop_checkpoint(sbi, true,
+ STOP_CP_REASON_WRITE_FAIL);
}

f2fs_bug_on(sbi, page->mapping == NODE_MAPPING(sbi) &&
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index d680a051cba4..ebda0ce1adbf 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3559,6 +3559,7 @@ int f2fs_enable_quota_files(struct f2fs_sb_info *sbi, bool rdonly);
int f2fs_quota_sync(struct super_block *sb, int type);
loff_t max_file_blocks(struct inode *inode);
void f2fs_quota_off_umount(struct super_block *sb);
+void f2fs_update_sb_flags(struct f2fs_sb_info *sbi, unsigned char reason);
int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover);
int f2fs_sync_fs(struct super_block *sb, int sync);
int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi);
@@ -3718,7 +3719,8 @@ static inline bool f2fs_need_rand_seg(struct f2fs_sb_info *sbi)
/*
* checkpoint.c
*/
-void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io);
+void f2fs_stop_checkpoint(struct f2fs_sb_info *sbi, bool end_io,
+ unsigned char reason);
void f2fs_flush_ckpt_thread(struct f2fs_sb_info *sbi);
struct page *f2fs_grab_meta_page(struct f2fs_sb_info *sbi, pgoff_t index);
struct page *f2fs_get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 2f9b387fef54..da45798d7fe5 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2153,7 +2153,8 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
if (ret) {
if (ret == -EROFS) {
ret = 0;
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false,
+ STOP_CP_REASON_SHUTDOWN);
set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
trace_f2fs_shutdown(sbi, in, ret);
}
@@ -2166,7 +2167,7 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
ret = freeze_bdev(sb->s_bdev);
if (ret)
goto out;
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_SHUTDOWN);
set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
thaw_bdev(sb->s_bdev);
break;
@@ -2175,16 +2176,16 @@ static int f2fs_ioc_shutdown(struct file *filp, unsigned long arg)
ret = f2fs_sync_fs(sb, 1);
if (ret)
goto out;
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_SHUTDOWN);
set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
break;
case F2FS_GOING_DOWN_NOSYNC:
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_SHUTDOWN);
set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
break;
case F2FS_GOING_DOWN_METAFLUSH:
f2fs_sync_meta_pages(sbi, META, LONG_MAX, FS_META_IO);
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_SHUTDOWN);
set_sbi_flag(sbi, SBI_IS_SHUTDOWN);
break;
case F2FS_GOING_DOWN_NEED_FSCK:
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 3a820e5cdaee..6e42dad0ac2d 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -74,7 +74,8 @@ static int gc_thread_func(void *data)

if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
f2fs_show_injection_info(sbi, FAULT_CHECKPOINT);
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false,
+ STOP_CP_REASON_FAULT_INJECT);
}

if (!sb_start_write_trylock(sbi->sb)) {
@@ -1712,7 +1713,8 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
segno, type, GET_SUM_TYPE((&sum->footer)));
set_sbi_flag(sbi, SBI_NEED_FSCK);
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false,
+ STOP_CP_REASON_CORRUPTED_SUMMARY);
goto skip;
}

diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index f6cb8b78b5d5..7880596b51ee 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -716,7 +716,8 @@ void f2fs_update_inode_page(struct inode *inode)
cond_resched();
goto retry;
} else if (err != -ENOENT) {
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false,
+ STOP_CP_REASON_UPDATE_INODE);
}
return;
}
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index e35be4116767..4ed84510f195 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -390,7 +390,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
{
if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
f2fs_show_injection_info(sbi, FAULT_CHECKPOINT);
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false, STOP_CP_REASON_FAULT_INJECT);
}

/* balance_fs_bg is able to be pending */
@@ -708,7 +708,8 @@ int f2fs_flush_device_cache(struct f2fs_sb_info *sbi)
} while (ret && --count);

if (ret) {
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_stop_checkpoint(sbi, false,
+ STOP_CP_REASON_FLUSH_FAIL);
break;
}

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index b8e5fe244596..9f0a64b4c5c6 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -3846,6 +3846,31 @@ int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
return err;
}

+void f2fs_update_sb_flags(struct f2fs_sb_info *sbi, unsigned char reason)
+{
+ struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+ unsigned short s_flags;
+ int err;
+
+ f2fs_bug_on(sbi, reason >= MAX_STOP_REASON);
+
+ f2fs_down_write(&sbi->sb_lock);
+
+ raw_super->s_stop_reason[reason]++;
+
+ s_flags = le16_to_cpu(raw_super->s_flags);
+
+ if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
+ raw_super->s_flags = cpu_to_le16(s_flags | SB_NEED_FSCK);
+
+ err = f2fs_commit_super(sbi, false);
+ if (err)
+ f2fs_warn(sbi, "f2fs_commit_super fails to persist flag: %u, reason:%u err:%d",
+ s_flags | SB_NEED_FSCK, reason, err);
+
+ f2fs_up_write(&sbi->sb_lock);
+}
+
static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
{
struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
index d445150c5350..adeaac71a563 100644
--- a/include/linux/f2fs_fs.h
+++ b/include/linux/f2fs_fs.h
@@ -73,6 +73,22 @@ struct f2fs_device {
__le32 total_segments;
} __packed;

+/* reason of stop_checkpoint */
+enum {
+ STOP_CP_REASON_SHUTDOWN,
+ STOP_CP_REASON_FAULT_INJECT,
+ STOP_CP_REASON_META_PAGE,
+ STOP_CP_REASON_WRITE_FAIL,
+ STOP_CP_REASON_CORRUPTED_SUMMARY,
+ STOP_CP_REASON_UPDATE_INODE,
+ STOP_CP_REASON_FLUSH_FAIL,
+ STOP_CP_REASON_MAX,
+};
+
+#define MAX_STOP_REASON 32
+
+#define SB_NEED_FSCK 0x00000001 /* need fsck */
+
struct f2fs_super_block {
__le32 magic; /* Magic Number */
__le16 major_ver; /* Major Version */
@@ -116,7 +132,9 @@ struct f2fs_super_block {
__u8 hot_ext_count; /* # of hot file extension */
__le16 s_encoding; /* Filename charset encoding */
__le16 s_encoding_flags; /* Filename charset encoding flags */
- __u8 reserved[306]; /* valid reserved region */
+ __le16 s_flags; /* super block flags */
+ __u8 s_stop_reason[MAX_STOP_REASON]; /* stop checkpoint reason */
+ __u8 reserved[272]; /* valid reserved region */
__le32 crc; /* checksum of superblock */
} __packed;

--
2.36.1

>
>>
>> Thanks
>>
>>>
>>>> + }
>>>> }
>>>> /*
>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>>>> index dee7b67a17a6..1960a98c7555 100644
>>>> --- a/fs/f2fs/f2fs.h
>>>> +++ b/fs/f2fs/f2fs.h
>>>> @@ -3556,6 +3556,7 @@ int f2fs_enable_quota_files(struct f2fs_sb_info *sbi, bool rdonly);
>>>> int f2fs_quota_sync(struct super_block *sb, int type);
>>>> loff_t max_file_blocks(struct inode *inode);
>>>> void f2fs_quota_off_umount(struct super_block *sb);
>>>> +void f2fs_update_sb_flags(struct f2fs_sb_info *sbi, unsigned int flag);
>>>> int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover);
>>>> int f2fs_sync_fs(struct super_block *sb, int sync);
>>>> int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi);
>>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>>> index b8e5fe244596..c99ba840593d 100644
>>>> --- a/fs/f2fs/super.c
>>>> +++ b/fs/f2fs/super.c
>>>> @@ -3846,6 +3846,32 @@ int f2fs_commit_super(struct f2fs_sb_info *sbi, bool recover)
>>>> return err;
>>>> }
>>>> +void f2fs_update_sb_flags(struct f2fs_sb_info *sbi, unsigned int flag)
>>>> +{
>>>> + unsigned short s_flags;
>>>> + int err;
>>>> +
>>>> + if (le16_to_cpu(F2FS_RAW_SUPER(sbi)->s_flags) & SB_NEED_FSCK)
>>>> + return;
>>>> +
>>>> + f2fs_down_write(&sbi->sb_lock);
>>>> +
>>>> + s_flags = le16_to_cpu(F2FS_RAW_SUPER(sbi)->s_flags);
>>>> +
>>>> + if (s_flags & SB_NEED_FSCK)
>>>> + goto out_unlock;
>>>> +
>>>> + F2FS_RAW_SUPER(sbi)->s_flags = cpu_to_le16(s_flags | SB_NEED_FSCK);
>>>> +
>>>> + err = f2fs_commit_super(sbi, false);
>>>> + if (err) {
>>>> + f2fs_warn(sbi, "f2fs_commit_super fails to persist flag: %u, err:%d", flag, err);
>>>> + F2FS_RAW_SUPER(sbi)->s_flags = s_flags;
>>>> + }
>>>> +out_unlock:
>>>> + f2fs_up_write(&sbi->sb_lock);
>>>> +}
>>>> +
>>>> static int f2fs_scan_devices(struct f2fs_sb_info *sbi)
>>>> {
>>>> struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
>>>> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
>>>> index d445150c5350..124176e2a42c 100644
>>>> --- a/include/linux/f2fs_fs.h
>>>> +++ b/include/linux/f2fs_fs.h
>>>> @@ -73,6 +73,8 @@ struct f2fs_device {
>>>> __le32 total_segments;
>>>> } __packed;
>>>> +#define SB_NEED_FSCK 0x00000001 /* need fsck */
>>>> +
>>>> struct f2fs_super_block {
>>>> __le32 magic; /* Magic Number */
>>>> __le16 major_ver; /* Major Version */
>>>> @@ -116,7 +118,8 @@ struct f2fs_super_block {
>>>> __u8 hot_ext_count; /* # of hot file extension */
>>>> __le16 s_encoding; /* Filename charset encoding */
>>>> __le16 s_encoding_flags; /* Filename charset encoding flags */
>>>> - __u8 reserved[306]; /* valid reserved region */
>>>> + __le16 s_flags; /* super block flags */
>>>> + __u8 reserved[304]; /* valid reserved region */
>>>> __le32 crc; /* checksum of superblock */
>>>> } __packed;
>>>> --
>>>> 2.25.1