[f2fs-dev] [PATCH] fsck.f2fs: allow fsck to fix issues with online resize due to SPO

[Sahitya Tummala <stummala@codeaurora.org>]

Add support for new CP flag CP_RESIZEFS_FLAG set during online
resize FS. If SPO happens after SB is updated but CP isn't, then
allow fsck to fix it.

fsck errors without this fix -
    Info: CKPT version = 6ed7bccb
            Wrong user_block_count(2233856)
    [f2fs_do_mount:3365] Checkpoint is polluted

the subsequent mount failure without this fix -
[   11.294650] F2FS-fs (sda8): Wrong user_block_count: 2233856
[   11.300272] F2FS-fs (sda8): Failed to get valid F2FS checkpoint

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
---
 fsck/mount.c      | 30 +++++++++++++++++++++++++++---
 include/f2fs_fs.h |  1 +
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/fsck/mount.c b/fsck/mount.c
index e4ba048..374c9c4 100644
--- a/fsck/mount.c
+++ b/fsck/mount.c
@@ -1128,6 +1128,7 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
 	unsigned int total, fsmeta;
 	struct f2fs_super_block *sb = F2FS_RAW_SUPER(sbi);
 	struct f2fs_checkpoint *cp = F2FS_CKPT(sbi);
+	unsigned int flag = get_cp(ckpt_flags);
 	unsigned int ovp_segments, reserved_segments;
 	unsigned int main_segs, blocks_per_seg;
 	unsigned int sit_segs, nat_segs;
@@ -1164,7 +1165,30 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
 	log_blocks_per_seg = get_sb(log_blocks_per_seg);
 	if (!user_block_count || user_block_count >=
 			segment_count_main << log_blocks_per_seg) {
-		MSG(0, "\tWrong user_block_count(%u)\n", user_block_count);
+		if (flag & CP_RESIZEFS_FLAG) {
+			u32 valid_user_block_cnt;
+			u32 seg_cnt_main = get_sb(segment_count) -
+					(get_sb(segment_count_ckpt) +
+					 get_sb(segment_count_sit) +
+					 get_sb(segment_count_nat) +
+					 get_sb(segment_count_ssa));
+
+			/* validate segment_count_main in sb first */
+			if (seg_cnt_main != get_sb(segment_count_main)) {
+				MSG(0, "inconsistent segment counts found\n");
+				return 1;
+			}
+			valid_user_block_cnt = ((get_sb(segment_count_main) -
+						get_cp(overprov_segment_count)) * c.blks_per_seg);
+			MSG(0, "Info: Fix wrong user_block_count in CP: (%u) -> (%u)\n",
+					user_block_count, valid_user_block_cnt);
+			set_cp(user_block_count, valid_user_block_cnt);
+			c.fix_on = 1;
+			c.bug_on = 1;
+		} else {
+			MSG(0, "\tWrong user_block_count(%u)\n", user_block_count);
+			return 1;
+		}
 		return 1;
 	}
 
@@ -3361,6 +3385,8 @@ int f2fs_do_mount(struct f2fs_sb_info *sbi)
 		return -1;
 	}
 
+	c.bug_on = 0;
+
 	if (sanity_check_ckpt(sbi)) {
 		ERR_MSG("Checkpoint is polluted\n");
 		return -1;
@@ -3380,8 +3406,6 @@ int f2fs_do_mount(struct f2fs_sb_info *sbi)
 			c.fix_on = 1;
 	}
 
-	c.bug_on = 0;
-
 	if (tune_sb_features(sbi))
 		return -1;
 
diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
index af31bc5..265f50c 100644
--- a/include/f2fs_fs.h
+++ b/include/f2fs_fs.h
@@ -678,6 +678,7 @@ struct f2fs_super_block {
 /*
  * For checkpoint
  */
+#define CP_RESIZEFS_FLAG                0x00004000
 #define CP_DISABLED_FLAG		0x00001000
 #define CP_QUOTA_NEED_FSCK_FLAG		0x00000800
 #define CP_LARGE_NAT_BITMAP_FLAG	0x00000400
-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.


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