The part (overprovision_segments - reserved_segments) can still be used for LFS in some case, e.g., there are lots of invalid block from dirty segments, then the part (overprovision_segments - reserved_segments) can be safely used. So free_use_blocks should use reserved_segments instead, rather than directly use overprovision_segments. BTW, we also add the constraint of sbi->reserved_blocks. Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx> --- fs/f2fs/gc.h | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h index 9325191..542612a 100644 --- a/fs/f2fs/gc.h +++ b/fs/f2fs/gc.h @@ -49,11 +49,23 @@ struct gc_inode_list { */ static inline block_t free_user_blocks(struct f2fs_sb_info *sbi) { - if (free_segments(sbi) < overprovision_segments(sbi)) + block_t avail_user_block_count, free_blocks, avail_free_blocks; + block_t reserved_blocks; + + avail_user_block_count = sbi->user_block_count - sbi->reserved_blocks; + + if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) + return 0; + + free_blocks = free_segments(sbi) << sbi->log_blocks_per_seg; + avail_free_blocks = min(free_blocks, avail_user_block_count - + sbi->total_valid_block_count); + reserved_blocks = reserved_segments(sbi) << sbi->log_blocks_per_seg; + + if (avail_free_blocks < reserved_blocks) return 0; else - return (free_segments(sbi) - overprovision_segments(sbi)) - << sbi->log_blocks_per_seg; + return avail_free_blocks - reserved_blocks; } static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi) -- 1.8.5.2