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From:   Daeho Jeong <daeho43@gmail.com>
To:     linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com
Cc:     Daeho Jeong <daehojeong@google.com>
Subject: [PATCH] f2fs: clean up zones when not successfully unmounted
Date:   Tue, 10 Oct 2023 12:36:28 -0700
Message-ID: <20231010193628.2629168-1-daeho43@gmail.com>
MIME-Version: 1.0
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Precedence: bulk

From: Daeho Jeong <daehojeong@google.com>

We can't trust write pointers when the previous mount was not
successfully unmounted.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
---
 fs/f2fs/segment.c | 92 ++++++++++++++++++++++++++++-------------------
 1 file changed, 56 insertions(+), 36 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index d05b41608fc0..727d016318f9 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -4910,22 +4910,31 @@ static int check_zone_write_pointer(struct f2fs_sb_info *sbi,
 	}
 
 	/*
-	 * The write pointer matches with the valid blocks or
-	 * already points to the end of the zone.
+	 * When safely unmounted in the previous mount, we can trust write
+	 * pointers. Otherwise, finish zones.
 	 */
-	if ((last_valid_block + 1 == wp_block) ||
-			(zone->wp == zone->start + zone->len))
-		return 0;
-
-	if (last_valid_block + 1 == zone_block) {
+	if (is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG)) {
 		/*
-		 * If there is no valid block in the zone and if write pointer
-		 * is not at zone start, reset the write pointer.
+		 * The write pointer matches with the valid blocks or
+		 * already points to the end of the zone.
 		 */
-		f2fs_notice(sbi,
-			    "Zone without valid block has non-zero write "
-			    "pointer. Reset the write pointer: wp[0x%x,0x%x]",
-			    wp_segno, wp_blkoff);
+		if ((last_valid_block + 1 == wp_block) ||
+				(zone->wp == zone->start + zone->len))
+			return 0;
+	}
+
+	if (last_valid_block + 1 == zone_block) {
+		if (is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG)) {
+			/*
+			 * If there is no valid block in the zone and if write
+			 * pointer is not at zone start, reset the write
+			 * pointer.
+			 */
+			f2fs_notice(sbi,
+			      "Zone without valid block has non-zero write "
+			      "pointer. Reset the write pointer: wp[0x%x,0x%x]",
+			      wp_segno, wp_blkoff);
+		}
 		ret = __f2fs_issue_discard_zone(sbi, fdev->bdev, zone_block,
 					zone->len >> log_sectors_per_block);
 		if (ret)
@@ -4935,18 +4944,20 @@ static int check_zone_write_pointer(struct f2fs_sb_info *sbi,
 		return ret;
 	}
 
-	/*
-	 * If there are valid blocks and the write pointer doesn't
-	 * match with them, we need to report the inconsistency and
-	 * fill the zone till the end to close the zone. This inconsistency
-	 * does not cause write error because the zone will not be selected
-	 * for write operation until it get discarded.
-	 */
-	f2fs_notice(sbi, "Valid blocks are not aligned with write pointer: "
-		    "valid block[0x%x,0x%x] wp[0x%x,0x%x]",
-		    GET_SEGNO(sbi, last_valid_block),
-		    GET_BLKOFF_FROM_SEG0(sbi, last_valid_block),
-		    wp_segno, wp_blkoff);
+	if (is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG)) {
+		/*
+		 * If there are valid blocks and the write pointer doesn't match
+		 * with them, we need to report the inconsistency and fill
+		 * the zone till the end to close the zone. This inconsistency
+		 * does not cause write error because the zone will not be
+		 * selected for write operation until it get discarded.
+		 */
+		f2fs_notice(sbi, "Valid blocks are not aligned with write "
+			    "pointer: valid block[0x%x,0x%x] wp[0x%x,0x%x]",
+			    GET_SEGNO(sbi, last_valid_block),
+			    GET_BLKOFF_FROM_SEG0(sbi, last_valid_block),
+			    wp_segno, wp_blkoff);
+	}
 
 	ret = blkdev_zone_mgmt(fdev->bdev, REQ_OP_ZONE_FINISH,
 				zone->start, zone->len, GFP_NOFS);
@@ -5020,18 +5031,27 @@ static int fix_curseg_write_pointer(struct f2fs_sb_info *sbi, int type)
 	if (zone.type != BLK_ZONE_TYPE_SEQWRITE_REQ)
 		return 0;
 
-	wp_block = zbd->start_blk + (zone.wp >> log_sectors_per_block);
-	wp_segno = GET_SEGNO(sbi, wp_block);
-	wp_blkoff = wp_block - START_BLOCK(sbi, wp_segno);
-	wp_sector_off = zone.wp & GENMASK(log_sectors_per_block - 1, 0);
-
-	if (cs->segno == wp_segno && cs->next_blkoff == wp_blkoff &&
-		wp_sector_off == 0)
-		return 0;
+	/*
+	 * When safely unmounted in the previous mount, we could use current
+	 * segments. Otherwise, allocate new sections.
+	 */
+	if (is_set_ckpt_flags(sbi, CP_UMOUNT_FLAG)) {
+		wp_block = zbd->start_blk + (zone.wp >> log_sectors_per_block);
+		wp_segno = GET_SEGNO(sbi, wp_block);
+		wp_blkoff = wp_block - START_BLOCK(sbi, wp_segno);
+		wp_sector_off = zone.wp & GENMASK(log_sectors_per_block - 1, 0);
+
+		if (cs->segno == wp_segno && cs->next_blkoff == wp_blkoff &&
+				wp_sector_off == 0)
+			return 0;
 
-	f2fs_notice(sbi, "Unaligned curseg[%d] with write pointer: "
-		    "curseg[0x%x,0x%x] wp[0x%x,0x%x]",
-		    type, cs->segno, cs->next_blkoff, wp_segno, wp_blkoff);
+		f2fs_notice(sbi, "Unaligned curseg[%d] with write pointer: "
+			    "curseg[0x%x,0x%x] wp[0x%x,0x%x]", type, cs->segno,
+			    cs->next_blkoff, wp_segno, wp_blkoff);
+	} else {
+		f2fs_notice(sbi, "Not successfully unmounted in the previous "
+			    "mount");
+	}
 
 	f2fs_notice(sbi, "Assign new section to curseg[%d]: "
 		    "curseg[0x%x,0x%x]", type, cs->segno, cs->next_blkoff);
-- 
2.42.0.609.gbb76f46606-goog