Messages in this thread | | | From | Daeho Jeong <> | Date | Fri, 3 Sep 2021 21:40:13 -0700 | Subject | Re: [f2fs-dev] [PATCH v4] f2fs: introduce fragment allocation mode mount option |
| |
> As a per curseg field. > > > Maybe, we run into the same race condition issue you told before for > > fragment_remained_chunk. > > Could you clarify this more? > > e.g. > > F2FS_OPTION(sbi).fs_mode = FS_MODE_FRAGMENT_FIXED_BLK > fragment_chunk_size = 384 > fragment_hole_size = 384 > > When creating hole: > > - f2fs_allocate_data_block > - __refresh_next_blkoff > chunk locates in [0, 383] of current segment > seg->next_blkoff = 384 > sbi->fragment_remained_chunk = 0 > then we will reset sbi->fragment_remained_chunk to 384 > and move seg->next_blkoff forward to 768 (384 + 384) > - __has_curseg_space() returns false > - allocate_segment() allocates new current segment > > So, for such case that hole may cross two segments, hole size may be truncated > to left size of previous segment.
First, sbi->fragment_remained_chunk should be seg->fragment_remained_chunk. I understand what you mean, so you mean we need to take the leftover "hole" size over to the next segment? In the example, the leftover hole size will be (384 - (512-384)). Do you want to take this over to the next segment?
| |