Re: [PATCH v8 1/1] f2fs: ioctl for removing a range from F2FS
From: Chao Yu
Date: Tue Jun 11 2019 - 04:15:35 EST
On 2019/6/5 11:33, sunqiuyang wrote:
> From: Qiuyang Sun <sunqiuyang@xxxxxxxxxx>
> This ioctl shrinks a given length (aligned to sections) from end of the
> main area. Any cursegs and valid blocks will be moved out before
> invalidating the range.
> This feature can be used for adjusting partition sizes online.
> Changlog v1 ==> v2:
> Sahitya Tummala:
> - Add this ioctl for f2fs_compat_ioctl() as well.
> - Fix debugfs status to reflect the online resize changes.
> - Fix potential race between online resize path and allocate new data
> block path or gc path.
> - Rename some identifiers.
> - Add some error handling branches.
> - Clear sbi->next_victim_seg[BG_GC/FG_GC] in shrinking range.
> Changelog v2 ==> v3:
> Implement this interface as ext4's, and change the parameter from shrunk
> bytes to new block count of F2FS.
> Changelog v3 ==> v4:
> - During resizing, force to empty sit_journal and forbid adding new
> entries to it, in order to avoid invalid segno in journal after resize.
> - Reduce sbi->user_block_count before resize starts.
> - Commit the updated superblock first, and then update in-memory metadata
> only when the former succeeds.
> - Target block count must align to sections.
> Changelog v4 ==> v5:
> Write checkpoint before and after committing the new superblock, w/o
> CP_FSCK_FLAG respectively, so that the FS can be fixed by fsck even if
> resize fails after the new superblock is committed.
> Changelog v5 ==> v6:
> - In free_segment_range(), reduce granularity of gc_mutex.
> - Add protection on curseg migration.
> Changelog v6 ==> v7:
> - Add freeze_bdev() and thaw_bdev() for resize fs.
> - Remove CUR_MAIN_SECS and use MAIN_SECS directly for allocation.
> - Recover super_block and FS metadata when resize fails.
> Changelog v7 ==> v8:
> - No need to clear CP_FSCK_FLAG in update_ckpt_flags().
> - Clean up the sb and fs metadata update functions for resize_fs.
> Signed-off-by: Qiuyang Sun <sunqiuyang@xxxxxxxxxx>
> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> Signed-off-by: Sahitya Tummala <stummala@xxxxxxxxxxxxxx>
Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>
Qiuyang, could you please add one f2fs individual testcase in fstest suit to do
simple test with this ioctl.
- mkfs & mount
- fragment image
- resizefs ioctl
- check fs size via statfs
- umount & fsck
- maybe mount & check again