[PATCH] fsck.f2fs: recover nat bits feature default by fsck

[Yunlei He <heyunlei@huawei.com>]

Now, nat bits feature is enabled by default, we will
meet with the following scenarios:

i.   disabled, without CP_NAT_BITS_FLAG, if fsck find some
     fs errors, fix or write new checkpoint will then enable it.
ii.  enabled, with CP_NAT_BITS_FLAG, in the case of sudden
     power off, bitmap will get lost but CP_NAT_BITS_FLAG
     still exist, fsck will recover bitmap in f2fs_do_mount.
iii. enabled, with CP_NAT_BITS_FLAG, both of bitmap and
     CP_NAT_BITS_FLAG will get lost if not enough space for
     nat bits or nat bits check failed during mounting.
     SBI_NEED_FSCK is set, fsck will recover flag and bitmap
     before next mount.

SBI_NEED_FSCK means fs is corrupted, is not suitable for
nat bits disabled. This patch try to recover nat bits all
by fsck, no need set SBI_NEED_FSCK flag in kernel.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
---
 fsck/mount.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/fsck/mount.c b/fsck/mount.c
index e5574c5..2361ee0 100644
--- a/fsck/mount.c
+++ b/fsck/mount.c
@@ -2389,7 +2389,7 @@ int f2fs_do_mount(struct f2fs_sb_info *sbi)
 	}
 
 	/* Check nat_bits */
-	if (c.func != DUMP && is_set_ckpt_flags(cp, CP_NAT_BITS_FLAG)) {
+	if (c.func != DUMP) {
 		u_int32_t nat_bits_bytes, nat_bits_blocks;
 		__le64 *kaddr;
 		u_int32_t blk;
@@ -2406,10 +2406,15 @@ int f2fs_do_mount(struct f2fs_sb_info *sbi)
 		kaddr = malloc(PAGE_SIZE);
 		ret = dev_read_block(kaddr, blk);
 		ASSERT(ret >= 0);
-		if (*kaddr != get_cp_crc(cp))
-			write_nat_bits(sbi, sb, cp, sbi->cur_cp);
-		else
-			MSG(0, "Info: Found valid nat_bits in checkpoint\n");
+		if(is_set_ckpt_flags(cp, CP_NAT_BITS_FLAG)) {
+			if (*kaddr != get_cp_crc(cp))
+				write_nat_bits(sbi, sb, cp, sbi->cur_cp);
+			else
+				MSG(0, "Info: Found valid nat_bits in checkpoint\n");
+		} else if (c.func == FSCK){
+			ASSERT_MSG("Need to recover nat_bits.");
+			c.fix_on = 1;
+		}
 		free(kaddr);
 	}
 	return 0;
-- 
1.9.1


------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot