resize.f2fs: fix to check free space before shrink

Otherwise, after shrink, kernel will report below error message
when we mount the image:

F2FS-fs (loop0): invalid crc_offset: 0
F2FS-fs (loop0): Wrong valid_user_blocks: 16404, user_block_count: 13312
F2FS-fs (loop0): Failed to get valid F2FS checkpoint
mount(2) system call failed: Structure needs cleaning.

Reported-and-tested-by: beroal <me@beroal.in.ua>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fsck/resize.c b/fsck/resize.c
index a083f68..b043cd9 100644 (file)
--- a/fsck/resize.c
+++ b/fsck/resize.c
@@ -650,8 +650,11 @@ static int f2fs_resize_shrink(struct f2fs_sb_info *sbi)
        struct f2fs_super_block *sb = F2FS_RAW_SUPER(sbi);
        struct f2fs_super_block new_sb_raw;
        struct f2fs_super_block *new_sb = &new_sb_raw;
+       struct f2fs_checkpoint *cp = F2FS_CKPT(sbi);
        block_t old_end_blkaddr, old_main_blkaddr;
        block_t new_end_blkaddr, new_main_blkaddr, tmp_end_blkaddr;
+       block_t user_block_count;
+       unsigned int overprov_segment_count;
        unsigned int offset;
        int err = -1;
 
@@ -662,6 +665,17 @@ static int f2fs_resize_shrink(struct f2fs_sb_info *sbi)
        if (get_new_sb(new_sb))
                return -1;
 
+       overprov_segment_count = (get_newsb(segment_count_main) -
+                       c.new_reserved_segments) *
+                       c.new_overprovision / 100;
+       overprov_segment_count += c.new_reserved_segments;
+
+       user_block_count = (get_newsb(segment_count_main) -
+                       overprov_segment_count) * c.blks_per_seg;
+
+       if (get_cp(valid_block_count) > user_block_count)
+               return -1;
+
        /* check nat availability */
        if (get_sb(segment_count_nat) > get_newsb(segment_count_nat)) {
                err = shrink_nats(sbi, new_sb);