Messages in this thread | | | Subject | Re: [f2fs-dev] [PATCH] f2fs: change the way of handling range.len in F2FS_IOC_SEC_TRIM_FILE | From | Chao Yu <> | Date | Fri, 10 Jul 2020 14:31:03 +0800 |
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On 2020/7/10 11:52, Jaegeuk Kim wrote: > On 07/10, Chao Yu wrote: >> 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? > > Like Daeho said, write_begin -> checkpoint -> power-cut can give bigger i_blocks > than i_size.
The path won't, cp only persists reserved block in dnode rather than written data block in segment, because data will be copied to page cache after write_begin.
I think truncation path could as Daeho said:
1. truncate -> i_size update however blocks wasn't truncated yet -> checkpoint -> recovery 2. truncate failed -> i_size update however partial blocks was truncated -> fsync
> >> >>> >>>> >>>> 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 >>>>> . >>>>> >>> . >>> > . >
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