Re: [f2fs-dev] [RFC PATCH] f2fs: don't set SBI_QUOTA_NEED_REPAIR flag if receive SIGKILL

[wangzijie]

>> From: Chao Yu via Linux-f2fs-devel <linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx>
>> 
>>> On 2024/8/27 14:22, wangzijie wrote:
>>>> Thread A
>>>> -dquot_initialize
>>>>   -dqget
>>>>    -f2fs_dquot_acquire
>>>>     -v2_read_dquot
>>>>      -qtree_read_dquot
>>>>       -find_tree_dqentry
>>>>        -f2fs_quota_read
>>>>         -read_cache_page_gfp
>>>>          -do_read_cache_folio
>>>>           -fiemap_read_folio
>>>>            -folio_wait_locked_killable
>>>>             -receive SIGKILL : return -EINTR
>>>>         -set SBI_QUOTA_NEED_REPAIR
>>>>     -set SBI_QUOTA_NEED_REPAIR
>>>>
>>>> When calling read_cache_page_gfp in quota read, thread may receive SIGKILL and
>>>> set SBI_QUOTA_NEED_REPAIR, should we set SBI_QUOTA_NEED_REPAIR in this error path?
>>>
>>> f2fs_quota_read() can be called in a lot of contexts, can we just ignore -EINTR
>>> for f2fs_dquot_initialize() case?
>>>
>>> Thanks,
>> 
>> Yes, in many contexts f2fs_quota_read() can be called and may return -EINTR, we need to ignore this errno for more cases. If we need to do so, I will check it and resend patch.
>> Or do you have other suggestions to avoid unnecessary SBI_QUOTA_NEED_REPAIR flag set?
>
>How about this?
>
>---
>  fs/f2fs/f2fs.h  |  1 +
>  fs/f2fs/inode.c |  3 +--
>  fs/f2fs/super.c | 17 +++++++++++++----
>  3 files changed, 15 insertions(+), 6 deletions(-)
>
>diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>index dfed1974eda5..a1704a19dfe9 100644
>--- a/fs/f2fs/f2fs.h
>+++ b/fs/f2fs/f2fs.h
>@@ -810,6 +810,7 @@ enum {
>  	FI_ATOMIC_DIRTIED,	/* indicate atomic file is dirtied */
>  	FI_ATOMIC_REPLACE,	/* indicate atomic replace */
>  	FI_OPENED_FILE,		/* indicate file has been opened */
>+	FI_INIT_DQUOT,		/* indicate it's initializing dquot */
>  	FI_MAX,			/* max flag, never be used */
>  };
>
>diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
>index 008f01348afa..b1dbaeda306f 100644
>--- a/fs/f2fs/inode.c
>+++ b/fs/f2fs/inode.c
>@@ -827,8 +827,7 @@ void f2fs_evict_inode(struct inode *inode)
>
>  	err = f2fs_dquot_initialize(inode);
>  	if (err) {
>-		if (err != -EINTR)
>-			set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
>+		set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
>  		err = 0;
>  	}
>
>diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>index 8e29aba4b7a4..e774bdf875b2 100644
>--- a/fs/f2fs/super.c
>+++ b/fs/f2fs/super.c
>@@ -2644,8 +2644,11 @@ static ssize_t f2fs_quota_read(struct super_block *sb, int type, char *data,
>  			if (PTR_ERR(page) == -ENOMEM) {
>  				memalloc_retry_wait(GFP_NOFS);
>  				goto repeat;
>-			} else if (PTR_ERR(page) != -EINTR)
>-				set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR);
>+			} else if (PTR_ERR(page) == -EINTR &&
>+				is_inode_flag_set(inode, FI_INIT_DQUOT)) {
>+				return PTR_ERR(page);
>+			}
>+			set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR);
>  			return PTR_ERR(page);
>  		}
>
>@@ -2721,10 +2724,16 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type,
>
>  int f2fs_dquot_initialize(struct inode *inode)
>  {
>+	int ret;
>+
>  	if (time_to_inject(F2FS_I_SB(inode), FAULT_DQUOT_INIT))
>  		return -ESRCH;
>
>-	return dquot_initialize(inode);
>+	set_inode_flag(inode, FI_INIT_DQUOT);
>+	ret = dquot_initialize(inode);
>+	clear_inode_flag(inode, FI_INIT_DQUOT);
>+
>+	return ret;
>  }
>
>  static struct dquot __rcu **f2fs_get_dquots(struct inode *inode)
>@@ -3064,7 +3073,7 @@ static int f2fs_dquot_acquire(struct dquot *dquot)
>
>  	f2fs_down_read(&sbi->quota_sem);
>  	ret = dquot_acquire(dquot);
>-	if (ret < 0 && ret != -EINTR)
>+	if (ret < 0)
>  		set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
>  	f2fs_up_read(&sbi->quota_sem);
>  	return ret;
>-- 
>2.40.1

Hi, Chao
If we dont't ignore -EINTR in f2fs_dquot_acquire(), we will still set SBI_QUOTA_NEED_REPAIR flag
in f2fs_dquot_acquire() if f2fs_quota_read return -EINTR. I think we need more cases in addition to 
dquot initializing and I will check it again.
Thank you for your suggestion!

>> 
>> Thank you for review.
>> 
>>>>
>>>> Signed-off-by: wangzijie <wangzijie1@xxxxxxxxx>
>>>> ---
>>>>   fs/f2fs/inode.c | 3 ++-
>>>>   fs/f2fs/super.c | 6 +++---
>>>>   2 files changed, 5 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
>>>> index ed629dabb..2af98e2b7 100644
>>>> --- a/fs/f2fs/inode.c
>>>> +++ b/fs/f2fs/inode.c
>>>> @@ -837,8 +837,9 @@ void f2fs_evict_inode(struct inode *inode)
>>>>       err = f2fs_dquot_initialize(inode);
>>>>       if (err) {
>>>> +        if (err != -EINTR)
>>>> +            set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
>>>>           err = 0;
>>>> -        set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
>>>>       }
>>>>       f2fs_remove_ino_entry(sbi, inode->i_ino, APPEND_INO);
>>>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>>>> index 1f1b3647a..f99a36ff3 100644
>>>> --- a/fs/f2fs/super.c
>>>> +++ b/fs/f2fs/super.c
>>>> @@ -2650,8 +2650,8 @@ static ssize_t f2fs_quota_read(struct super_block *sb, int type, char *data,
>>>>               if (PTR_ERR(page) == -ENOMEM) {
>>>>                   memalloc_retry_wait(GFP_NOFS);
>>>>                   goto repeat;
>>>> -            }
>>>> -            set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR);
>>>> +            } else if (PTR_ERR(page) != -EINTR)
>>>> +                set_sbi_flag(F2FS_SB(sb), SBI_QUOTA_NEED_REPAIR);
>>>>               return PTR_ERR(page);
>>>>           }
>>>> @@ -3070,7 +3070,7 @@ static int f2fs_dquot_acquire(struct dquot *dquot)
>>>>       f2fs_down_read(&sbi->quota_sem);
>>>>       ret = dquot_acquire(dquot);
>>>> -    if (ret < 0)
>>>> +    if (ret < 0 && ret != -EINTR)
>>>>           set_sbi_flag(sbi, SBI_QUOTA_NEED_REPAIR);
>>>>       f2fs_up_read(&sbi->quota_sem);
>>>>       return ret;
>> 
>>