lkml.org 
[lkml]   [2020]   [Jul]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [f2fs-dev] [PATCH] f2fs: change the way of handling range.len in F2FS_IOC_SEC_TRIM_FILE
From
Date
On 2020/7/10 11:31, Jaegeuk Kim wrote:
> On 07/10, Chao Yu wrote:
>> On 2020/7/10 11:02, Jaegeuk Kim wrote:
>>> On 07/10, Daeho Jeong wrote:
>>>> From: Daeho Jeong <daehojeong@google.com>
>>>>
>>>> Changed the way of handling range.len of F2FS_IOC_SEC_TRIM_FILE.
>>>> 1. Added -1 value support for range.len to signify the end of file.
>>>> 2. If the end of the range passes over the end of file, it means until
>>>> the end of file.
>>>> 3. ignored the case of that range.len is zero to prevent the function
>>>> from making end_addr zero and triggering different behaviour of
>>>> the function.
>>>>
>>>> Signed-off-by: Daeho Jeong <daehojeong@google.com>
>>>> ---
>>>> fs/f2fs/file.c | 16 +++++++---------
>>>> 1 file changed, 7 insertions(+), 9 deletions(-)
>>>>
>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>>>> index 368c80f8e2a1..1c4601f99326 100644
>>>> --- a/fs/f2fs/file.c
>>>> +++ b/fs/f2fs/file.c
>>>> @@ -3813,21 +3813,19 @@ static int f2fs_sec_trim_file(struct file *filp, unsigned long arg)
>>>> file_start_write(filp);
>>>> inode_lock(inode);
>>>>
>>>> - if (f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode)) {
>>>> + if (f2fs_is_atomic_file(inode) || f2fs_compressed_file(inode) ||
>>>> + range.start >= inode->i_size) {
>>>> ret = -EINVAL;
>>>> goto err;
>>>> }
>>>>
>>>> - if (range.start >= inode->i_size) {
>>>> - ret = -EINVAL;
>>>> + if (range.len == 0)
>>>> goto err;
>>>> - }
>>>>
>>>> - if (inode->i_size - range.start < range.len) {
>>>> - ret = -E2BIG;
>>>> - goto err;
>>>> - }
>>>> - end_addr = range.start + range.len;
>>>> + if (range.len == (u64)-1 || inode->i_size - range.start < range.len)
>>>> + end_addr = inode->i_size;
>>
>> We can remove 'range.len == (u64)-1' condition since later condition can cover
>> this?
>>
>>>
>>> Hmm, what if there are blocks beyond i_size? Do we need to check i_blocks for
>>
>> The blocks beyond i_size will never be written, there won't be any valid message
>> there, so we don't need to worry about that.
>
> I don't think we have a way to guarantee the order of i_size and block
> allocation in f2fs. See f2fs_write_begin and f2fs_write_end.

However, write_begin & write_end are covered by inode_lock, it could not be
racy with inode size check in f2fs_sec_trim_file() as it hold inode_lock as
well?

>
>>
>> Thanks,
>>
>>> ending criteria?
>>>
>>>> + else
>>>> + end_addr = range.start + range.len;
>>>>
>>>> to_end = (end_addr == inode->i_size);
>>>> if (!IS_ALIGNED(range.start, F2FS_BLKSIZE) ||
>>>> --
>>>> 2.27.0.383.g050319c2ae-goog
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Linux-f2fs-devel mailing list
>>>> Linux-f2fs-devel@lists.sourceforge.net
>>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>>
>>>
>>> _______________________________________________
>>> Linux-f2fs-devel mailing list
>>> Linux-f2fs-devel@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>> .
>>>
> .
>

\
 
 \ /
  Last update: 2020-07-10 05:37    [W:0.070 / U:0.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site