On 2017/10/13 20:43, Chao Yu wrote:
>
> On 2017/10/14 0:59, Weichao Guo wrote:
>> Punching hole with a length which far larger than file size will cause
>> a long time looping in truncate_hole after lock_op, it can be
>> reproduced as the following:
>>
>> $ echo "abc" > file
>> $ xfs_io -c "fpunch 0 HUGE_LENGTH" file
>>
>> This may cause other I/Os blocked a long time. Let's fix this case by
>> setting the hole to end after the page that contains i_size.
> You know, we can reserve blocks across EOF through fallocate(fd,
> FALLOC_FL_KEEP_SIZE, ofs, len), so this patch will cause f2fs losing ability
> of punching preallocated blocks across EOF.
>
Oh, I see. Let me prepare another patch.
> How about below change:
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index cfee75bf88d9..91fd2ef7221b
> 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -847,7 +847,7 @@ int truncate_hole(struct inode *inode, pgoff_t pg_start,
> pgoff_t pg_end)
> err = get_dnode_of_data(&dn, pg_start, LOOKUP_NODE);
> if (err) {
> if (err == -ENOENT) {
> - pg_start++;
> + pg_start = get_next_page_offset(&dn, pg_start);
> continue;
> }
> return err;
>
> Thanks,
>
>>
>> Signed-off-by: Weichao Guo <[email protected]>
>> ---
>> fs/f2fs/file.c | 8 ++++++++
>> 1 file changed, 8 insertions(+)
>>
>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 517e112..1b44d26
>> 100644
>> --- a/fs/f2fs/file.c
>> +++ b/fs/f2fs/file.c
>> @@ -873,6 +873,14 @@ static int punch_hole(struct inode *inode, loff_t
>> offset, loff_t len)
>> if (ret)
>> return ret;
>>
>> + /*
>> + * If the hole extends beyond i_size, set the hole
>> + * to end after the page that contains i_size
>> + */
>> + if (offset + len > inode->i_size)
>> + len = inode->i_size + PAGE_CACHE_SIZE -
>> + (inode->i_size & (PAGE_CACHE_SIZE - 1)) - offset;
>> +
>> pg_start = ((unsigned long long) offset) >> PAGE_SHIFT;
>> pg_end = ((unsigned long long) offset + len) >> PAGE_SHIFT;
>>
>>
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