Re: [f2fs-dev] [RFC PATCH] f2fs: remove some redundant flow about FI_ATOMIC_DIRTIED
From: Chao Yu
Date: Wed Mar 26 2025 - 23:21:50 EST
On 3/27/25 02:51, Daeho Jeong wrote:
> On Wed, Mar 26, 2025 at 5:12 AM Chao Yu via Linux-f2fs-devel
> <linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> On 3/26/25 18:51, Zhiguo Niu wrote:
>>> Chao Yu <chao@xxxxxxxxxx> 于2025年3月26日周三 17:26写道：
>>>>
>>>> On 3/26/25 16:46, Zhiguo Niu wrote:
>>>>> Commit fccaa81de87e ("f2fs: prevent atomic file from being dirtied before commit")
>>>>> adds the processing of FI_ATOMIC_DIRTIED in the following two positions,
>>>>> [1]
>>>>> f2fs_commit_atomic_write
>>>>> - __f2fs_commit_atomic_write
>>>>> - sbi->committed_atomic_block += fi->atomic_write_cnt;
>>>>> - set_inode_flag(inode, FI_ATOMIC_COMMITTED);
>>>>> - if (is_inode_flag_set(inode, FI_ATOMIC_DIRTIED)) {
>>>>> - clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
>>>>> - f2fs_mark_inode_dirty_sync(inode, true);
>>>>> - }
>>>>> [2]
>>>>> f2fs_abort_atomic_write
>>>>> - if (is_inode_flag_set(inode, FI_ATOMIC_DIRTIED)) {
>>>>> - clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
>>>>> - f2fs_mark_inode_dirty_sync(inode, true);
>>>>> - }
>>>>>
>>>>> but [1] seems to be redundant:
>>>>> The atomic file flag FI_ATOMIC_FILE is still set here, so f2fs_mark_inode_dirty_sync
>>>>> still does not set the dirty state to vfs. If FI_ATOMIC_DIRTIED was originally set
>>>>> when atomic file is committing, then FI_ATOMIC_DIRTIED is just cleared here, and
>>>>> then do the repeating action of setting FI_ATOMIC_DIRTIED?
>>>>> So is it enough to do this only in [2]?
>>>>
>>>> Hi Zhiguo,
>>>>
>>>> I checked the code again, finally, I got this, could you please take
>>>> a look?
>>>>
>>>> Ping Daeho as well.
>>>>
>>>> Subject: [PATCH] f2fs: fix to set atomic write status more clear
>>>>
>>>> 1. After we start atomic write in a database file, before committing
>>>> all data, we'd better not set inode w/ vfs dirty status to avoid
>>>> redundant updates, instead, we only set inode w/ atomic dirty status.
>>>>
>>>> 2. After we commit all data, before committing metadata, we need to
>>>> clear atomic dirty status, and set vfs dirty status to allow vfs flush
>>>> dirty inode.
>>>>
>>> Hi Chao,
>>> these looks more clear.
>>>> Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
>>>> ---
>>>> fs/f2fs/inode.c | 4 +++-
>>>> fs/f2fs/segment.c | 10 ++++++----
>>>> fs/f2fs/super.c | 4 +++-
>>>> 3 files changed, 12 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
>>>> index 5c8634eaef7b..f5991e8751b9 100644
>>>> --- a/fs/f2fs/inode.c
>>>> +++ b/fs/f2fs/inode.c
>>>> @@ -34,7 +34,9 @@ void f2fs_mark_inode_dirty_sync(struct inode *inode, bool sync)
>>>> if (f2fs_inode_dirtied(inode, sync))
>>>> return;
>>>>
>>>> - if (f2fs_is_atomic_file(inode))
>>>> + /* only atomic file w/ FI_ATOMIC_COMMITTED can be set vfs dirty */
>>>> + if (f2fs_is_atomic_file(inode) &&
>>>> + !is_inode_flag_set(inode, FI_ATOMIC_COMMITTED))
>>>> return;
>>>>
>>>> mark_inode_dirty_sync(inode);
>>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>>> index dc360b4b0569..28659a71891a 100644
>>>> --- a/fs/f2fs/segment.c
>>>> +++ b/fs/f2fs/segment.c
>>>> @@ -376,10 +376,12 @@ static int __f2fs_commit_atomic_write(struct inode *inode)
>>>> } else {
>>>> sbi->committed_atomic_block += fi->atomic_write_cnt;
>>>> set_inode_flag(inode, FI_ATOMIC_COMMITTED);
>>>> - if (is_inode_flag_set(inode, FI_ATOMIC_DIRTIED)) {
>>>> - clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
>>>> - f2fs_mark_inode_dirty_sync(inode, true);
>>>> - }
>>>> +
>>>> + f2fs_bug_on(sbi, !is_inode_flag_set(inode, FI_ATOMIC_DIRTIED));
>>> but FI_ATOMIC_DIRTIED may not be set when atomic file is committing?
>>> thanks!
>>
>> inc_valid_block_count() will set FI_ATOMIC_DIRTIED for inode at least?
>>
>> - __f2fs_commit_atomic_write
>> - __replace_atomic_write_block
>> - inc_valid_block_count
>> - f2fs_i_blocks_write
>> - f2fs_mark_inode_dirty_sync
>
> Maybe, no write scenario? open -> atomic_write_start -> no write -> commit?
Oh, You're right.
Thanks,
>
>>
>> Thanks,
>>
>>>> +
>>>> + /* clear atomic dirty status and set vfs dirty status */
>>>> + clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
>>>> + f2fs_mark_inode_dirty_sync(inode, true);
>>>> }
>>>>
>>>> __complete_revoke_list(inode, &revoke_list, ret ? true : false);
>>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>>> index 9a42a1323f42..a5cc9f6ee16a 100644
>>>> --- a/fs/f2fs/super.c
>>>> +++ b/fs/f2fs/super.c
>>>> @@ -1532,7 +1532,9 @@ int f2fs_inode_dirtied(struct inode *inode, bool sync)
>>>> }
>>>> spin_unlock(&sbi->inode_lock[DIRTY_META]);
>>>>
>>>> - if (!ret && f2fs_is_atomic_file(inode))
>>>> + /* if atomic write is not committed, set inode w/ atomic dirty */
>>>> + if (!ret && f2fs_is_atomic_file(inode) &&
>>>> + !is_inode_flag_set(inode, FI_ATOMIC_COMMITTED))
>>>> set_inode_flag(inode, FI_ATOMIC_DIRTIED);
>>>>
>>>> return ret;
>>>> --
>>>> 2.48.1
>>>>
>>>>
>>>>>
>>>>> Cc: Daeho Jeong <daehojeong@xxxxxxxxxx>
>>>>> Fixes: fccaa81de87e ("f2fs: prevent atomic file from being dirtied before commit")
>>>>> Signed-off-by: Zhiguo Niu <zhiguo.niu@xxxxxxxxxx>
>>>>> ---
>>>>> fs/f2fs/segment.c | 4 ----
>>>>> 1 file changed, 4 deletions(-)
>>>>>
>>>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>>>> index 396ef71..d4ea3af 100644
>>>>> --- a/fs/f2fs/segment.c
>>>>> +++ b/fs/f2fs/segment.c
>>>>> @@ -376,10 +376,6 @@ static int __f2fs_commit_atomic_write(struct inode *inode)
>>>>> } else {
>>>>> sbi->committed_atomic_block += fi->atomic_write_cnt;
>>>>> set_inode_flag(inode, FI_ATOMIC_COMMITTED);
>>>>> - if (is_inode_flag_set(inode, FI_ATOMIC_DIRTIED)) {
>>>>> - clear_inode_flag(inode, FI_ATOMIC_DIRTIED);
>>>>> - f2fs_mark_inode_dirty_sync(inode, true);
>>>>> - }
>>>>> }
>>>>>
>>>>> __complete_revoke_list(inode, &revoke_list, ret ? true : false);
>>>>
>>
>>
>>
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