* [f2fs-dev] [PATCH] f2fs: fix to access i_size w/ i_size_read()
@ 2025-10-29 6:31 Chao Yu via Linux-f2fs-devel
2025-10-29 8:09 ` Yongpeng Yang
0 siblings, 1 reply; 4+ messages in thread
From: Chao Yu via Linux-f2fs-devel @ 2025-10-29 6:31 UTC (permalink / raw)
To: jaegeuk; +Cc: linux-kernel, linux-f2fs-devel
It recommends to use i_size_{read,write}() to access and update i_size,
otherwise, we may get wrong tearing value due to high 32-bits value
and low 32-bits value of i_size field are not updated atomically in
32-bits archicture machine.
Signed-off-by: Chao Yu <chao@kernel.org>
---
include/trace/events/f2fs.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index edbbd869078f..e1fae78d64a5 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -204,7 +204,7 @@ DECLARE_EVENT_CLASS(f2fs__inode,
__entry->pino = F2FS_I(inode)->i_pino;
__entry->mode = inode->i_mode;
__entry->nlink = inode->i_nlink;
- __entry->size = inode->i_size;
+ __entry->size = i_size_read(inode);
__entry->blocks = inode->i_blocks;
__entry->advise = F2FS_I(inode)->i_advise;
),
@@ -353,7 +353,7 @@ TRACE_EVENT(f2fs_unlink_enter,
TP_fast_assign(
__entry->dev = dir->i_sb->s_dev;
__entry->ino = dir->i_ino;
- __entry->size = dir->i_size;
+ __entry->size = i_size_read(dir);
__entry->blocks = dir->i_blocks;
__assign_str(name);
),
@@ -433,7 +433,7 @@ DECLARE_EVENT_CLASS(f2fs__truncate_op,
TP_fast_assign(
__entry->dev = inode->i_sb->s_dev;
__entry->ino = inode->i_ino;
- __entry->size = inode->i_size;
+ __entry->size = i_size_read(inode);
__entry->blocks = inode->i_blocks;
__entry->from = from;
),
@@ -1006,7 +1006,7 @@ TRACE_EVENT(f2fs_fallocate,
__entry->mode = mode;
__entry->offset = offset;
__entry->len = len;
- __entry->size = inode->i_size;
+ __entry->size = i_size_read(inode);
__entry->blocks = inode->i_blocks;
__entry->ret = ret;
),
--
2.49.0
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^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [f2fs-dev] [PATCH] f2fs: fix to access i_size w/ i_size_read()
2025-10-29 6:31 [f2fs-dev] [PATCH] f2fs: fix to access i_size w/ i_size_read() Chao Yu via Linux-f2fs-devel
@ 2025-10-29 8:09 ` Yongpeng Yang
2025-10-29 9:41 ` Chao Yu via Linux-f2fs-devel
0 siblings, 1 reply; 4+ messages in thread
From: Yongpeng Yang @ 2025-10-29 8:09 UTC (permalink / raw)
To: Chao Yu, jaegeuk; +Cc: Yongpeng Yang, linux-kernel, linux-f2fs-devel
On 10/29/25 14:31, Chao Yu via Linux-f2fs-devel wrote:
> It recommends to use i_size_{read,write}() to access and update i_size,
> otherwise, we may get wrong tearing value due to high 32-bits value
> and low 32-bits value of i_size field are not updated atomically in
> 32-bits archicture machine.
>
> Signed-off-by: Chao Yu <chao@kernel.org>
> ---
> include/trace/events/f2fs.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
> index edbbd869078f..e1fae78d64a5 100644
> --- a/include/trace/events/f2fs.h
> +++ b/include/trace/events/f2fs.h
> @@ -204,7 +204,7 @@ DECLARE_EVENT_CLASS(f2fs__inode,
> __entry->pino = F2FS_I(inode)->i_pino;
> __entry->mode = inode->i_mode;
> __entry->nlink = inode->i_nlink;
> - __entry->size = inode->i_size;
> + __entry->size = i_size_read(inode);
> __entry->blocks = inode->i_blocks;
> __entry->advise = F2FS_I(inode)->i_advise;
> ),
> @@ -353,7 +353,7 @@ TRACE_EVENT(f2fs_unlink_enter,
> TP_fast_assign(
> __entry->dev = dir->i_sb->s_dev;
> __entry->ino = dir->i_ino;
> - __entry->size = dir->i_size;
> + __entry->size = i_size_read(dir);
> __entry->blocks = dir->i_blocks;
> __assign_str(name);
> ),
> @@ -433,7 +433,7 @@ DECLARE_EVENT_CLASS(f2fs__truncate_op,
> TP_fast_assign(
> __entry->dev = inode->i_sb->s_dev;
> __entry->ino = inode->i_ino;
> - __entry->size = inode->i_size;
> + __entry->size = i_size_read(inode);
> __entry->blocks = inode->i_blocks;
> __entry->from = from;
> ),
> @@ -1006,7 +1006,7 @@ TRACE_EVENT(f2fs_fallocate,
> __entry->mode = mode;
> __entry->offset = offset;
> __entry->len = len;
> - __entry->size = inode->i_size;
> + __entry->size = i_size_read(inode);
> __entry->blocks = inode->i_blocks;
> __entry->ret = ret;
> ),
inode->i_size usage in fs/f2fs/ also needs to be updated. For example in
f2fs_need_verity(), which may not protected by inode_lock.
Yongpeng,
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https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [f2fs-dev] [PATCH] f2fs: fix to access i_size w/ i_size_read()
2025-10-29 8:09 ` Yongpeng Yang
@ 2025-10-29 9:41 ` Chao Yu via Linux-f2fs-devel
2025-10-29 11:12 ` Yongpeng Yang
0 siblings, 1 reply; 4+ messages in thread
From: Chao Yu via Linux-f2fs-devel @ 2025-10-29 9:41 UTC (permalink / raw)
To: Yongpeng Yang, jaegeuk; +Cc: Yongpeng Yang, linux-kernel, linux-f2fs-devel
On 10/29/25 16:09, Yongpeng Yang wrote:
> On 10/29/25 14:31, Chao Yu via Linux-f2fs-devel wrote:
>> It recommends to use i_size_{read,write}() to access and update i_size,
>> otherwise, we may get wrong tearing value due to high 32-bits value
>> and low 32-bits value of i_size field are not updated atomically in
>> 32-bits archicture machine.
>>
>> Signed-off-by: Chao Yu <chao@kernel.org>
>> ---
>> include/trace/events/f2fs.h | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
>> index edbbd869078f..e1fae78d64a5 100644
>> --- a/include/trace/events/f2fs.h
>> +++ b/include/trace/events/f2fs.h
>> @@ -204,7 +204,7 @@ DECLARE_EVENT_CLASS(f2fs__inode,
>> __entry->pino = F2FS_I(inode)->i_pino;
>> __entry->mode = inode->i_mode;
>> __entry->nlink = inode->i_nlink;
>> - __entry->size = inode->i_size;
>> + __entry->size = i_size_read(inode);
>> __entry->blocks = inode->i_blocks;
>> __entry->advise = F2FS_I(inode)->i_advise;
>> ),
>> @@ -353,7 +353,7 @@ TRACE_EVENT(f2fs_unlink_enter,
>> TP_fast_assign(
>> __entry->dev = dir->i_sb->s_dev;
>> __entry->ino = dir->i_ino;
>> - __entry->size = dir->i_size;
>> + __entry->size = i_size_read(dir);
>> __entry->blocks = dir->i_blocks;
>> __assign_str(name);
>> ),
>> @@ -433,7 +433,7 @@ DECLARE_EVENT_CLASS(f2fs__truncate_op,
>> TP_fast_assign(
>> __entry->dev = inode->i_sb->s_dev;
>> __entry->ino = inode->i_ino;
>> - __entry->size = inode->i_size;
>> + __entry->size = i_size_read(inode);
>> __entry->blocks = inode->i_blocks;
>> __entry->from = from;
>> ),
>> @@ -1006,7 +1006,7 @@ TRACE_EVENT(f2fs_fallocate,
>> __entry->mode = mode;
>> __entry->offset = offset;
>> __entry->len = len;
>> - __entry->size = inode->i_size;
>> + __entry->size = i_size_read(inode);
>> __entry->blocks = inode->i_blocks;
>> __entry->ret = ret;
>> ),
>
> inode->i_size usage in fs/f2fs/ also needs to be updated. For example in f2fs_need_verity(), which may not protected by inode_lock.
Accessing i_size directly in f2fs_need_verity() should be fine? Because fsverity
actived inode should be readonly.
Do you see any other cases which are not covered by inode_lock()?
Thanks,
>
> Yongpeng,
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [f2fs-dev] [PATCH] f2fs: fix to access i_size w/ i_size_read()
2025-10-29 9:41 ` Chao Yu via Linux-f2fs-devel
@ 2025-10-29 11:12 ` Yongpeng Yang
0 siblings, 0 replies; 4+ messages in thread
From: Yongpeng Yang @ 2025-10-29 11:12 UTC (permalink / raw)
To: Chao Yu, Yongpeng Yang, jaegeuk
Cc: Yongpeng Yang, linux-kernel, linux-f2fs-devel
On 10/29/25 17:41, Chao Yu via Linux-f2fs-devel wrote:
> On 10/29/25 16:09, Yongpeng Yang wrote:
>> On 10/29/25 14:31, Chao Yu via Linux-f2fs-devel wrote:
>>> It recommends to use i_size_{read,write}() to access and update i_size,
>>> otherwise, we may get wrong tearing value due to high 32-bits value
>>> and low 32-bits value of i_size field are not updated atomically in
>>> 32-bits archicture machine.
>>>
>>> Signed-off-by: Chao Yu <chao@kernel.org>
>>> ---
>>> include/trace/events/f2fs.h | 8 ++++----
>>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
>>> index edbbd869078f..e1fae78d64a5 100644
>>> --- a/include/trace/events/f2fs.h
>>> +++ b/include/trace/events/f2fs.h
>>> @@ -204,7 +204,7 @@ DECLARE_EVENT_CLASS(f2fs__inode,
>>> __entry->pino = F2FS_I(inode)->i_pino;
>>> __entry->mode = inode->i_mode;
>>> __entry->nlink = inode->i_nlink;
>>> - __entry->size = inode->i_size;
>>> + __entry->size = i_size_read(inode);
>>> __entry->blocks = inode->i_blocks;
>>> __entry->advise = F2FS_I(inode)->i_advise;
>>> ),
>>> @@ -353,7 +353,7 @@ TRACE_EVENT(f2fs_unlink_enter,
>>> TP_fast_assign(
>>> __entry->dev = dir->i_sb->s_dev;
>>> __entry->ino = dir->i_ino;
>>> - __entry->size = dir->i_size;
>>> + __entry->size = i_size_read(dir);
>>> __entry->blocks = dir->i_blocks;
>>> __assign_str(name);
>>> ),
>>> @@ -433,7 +433,7 @@ DECLARE_EVENT_CLASS(f2fs__truncate_op,
>>> TP_fast_assign(
>>> __entry->dev = inode->i_sb->s_dev;
>>> __entry->ino = inode->i_ino;
>>> - __entry->size = inode->i_size;
>>> + __entry->size = i_size_read(inode);
>>> __entry->blocks = inode->i_blocks;
>>> __entry->from = from;
>>> ),
>>> @@ -1006,7 +1006,7 @@ TRACE_EVENT(f2fs_fallocate,
>>> __entry->mode = mode;
>>> __entry->offset = offset;
>>> __entry->len = len;
>>> - __entry->size = inode->i_size;
>>> + __entry->size = i_size_read(inode);
>>> __entry->blocks = inode->i_blocks;
>>> __entry->ret = ret;
>>> ),
>>
>> inode->i_size usage in fs/f2fs/ also needs to be updated. For example in f2fs_need_verity(), which may not protected by inode_lock.
>
> Accessing i_size directly in f2fs_need_verity() should be fine? Because fsverity
> actived inode should be readonly.
Yes, it's fine.>
> Do you see any other cases which are not covered by inode_lock()?
I checked again, no other cases.:)>
> Thanks,
>
>>
>> Yongpeng,
>
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
_______________________________________________
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^ permalink raw reply [flat|nested] 4+ messages in thread
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2025-10-29 6:31 [f2fs-dev] [PATCH] f2fs: fix to access i_size w/ i_size_read() Chao Yu via Linux-f2fs-devel
2025-10-29 8:09 ` Yongpeng Yang
2025-10-29 9:41 ` Chao Yu via Linux-f2fs-devel
2025-10-29 11:12 ` Yongpeng Yang
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