[PATCH RFC 11/11] btrfs: warn and clear bitmaps if there is dirty bitmap at mount time

From: Qu Wenruo <wqu@suse.com>
To: linux-btrfs@vger.kernel.org
Subject: [PATCH RFC 11/11] btrfs: warn and clear bitmaps if there is dirty bitmap at mount time
Date: Tue,  5 Jul 2022 15:39:13 +0800	[thread overview]
Message-ID: <9a9ffca76a342d2277059b71c2e23b879d31e608.1657004556.git.wqu@suse.com> (raw)
In-Reply-To: <cover.1657004556.git.wqu@suse.com>

To properly cleanup the bitmaps, we need to scrub the logical ranges in
the bitmaps.

Unfortunately there is no such convient interface at all (scrub only
works at device offset for now).

So just introduce a place holder to warn and clear the bitmap.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/disk-io.c      |  7 +++++++
 fs/btrfs/write-intent.c | 35 +++++++++++++++++++++++++++++++++++
 fs/btrfs/write-intent.h | 10 ++++++++++
 3 files changed, 52 insertions(+)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index bd30decd38e4..ccc136023303 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3705,6 +3705,13 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 			  ret);
 		goto fail_block_groups;
 	}
+
+	ret = btrfs_write_intent_recover(fs_info);
+	if (ret < 0) {
+		btrfs_err(fs_info, "failed to recover write-intent bitmap: %d",
+			  ret);
+		goto fail_block_groups;
+	}
 	ret = btrfs_recover_balance(fs_info);
 	if (ret) {
 		btrfs_err(fs_info, "failed to recover balance: %d", ret);
diff --git a/fs/btrfs/write-intent.c b/fs/btrfs/write-intent.c
index c8bee0f89fc9..529690fdfb0c 100644
--- a/fs/btrfs/write-intent.c
+++ b/fs/btrfs/write-intent.c
@@ -763,6 +763,41 @@ void btrfs_write_intent_clear_dirty(struct btrfs_fs_info *fs_info, u64 logical,
 	spin_unlock_irqrestore(&ctrl->lock, flags);
 }
 
+int btrfs_write_intent_recover(struct btrfs_fs_info *fs_info)
+{
+	struct write_intent_ctrl *ctrl = fs_info->wi_ctrl;
+	struct write_intent_super *wis;
+	int ret = 0;
+
+	if (!btrfs_fs_compat_ro(fs_info, WRITE_INTENT_BITMAP))
+		return ret;
+
+	ASSERT(ctrl);
+	wis = page_address(ctrl->page);
+
+	if (wi_super_nr_entries(wis) != 0) {
+		int i;
+
+		btrfs_warn(fs_info, "dirty write intent bitmap found:");
+		for (i = 0; i < wi_super_nr_entries(wis); i++) {
+			struct write_intent_entry *entry =
+				write_intent_entry_nr(ctrl, i);
+
+			btrfs_warn(fs_info,
+				"  entry=%u bytenr=%llu bitmap=0x%016llx\n", i,
+				   wi_entry_bytenr(entry),
+				   wi_entry_raw_bitmap(entry));
+		}
+		/* For now, we just clear the whole bitmap. */
+		memzero_page(ctrl->page, sizeof(struct write_intent_super),
+			     WRITE_INTENT_BITMAPS_SIZE -
+			     sizeof(struct write_intent_super));
+		wi_set_super_nr_entries(wis, 0);
+		ret = write_intent_writeback(fs_info);
+	}
+	return ret;
+}
+
 int btrfs_write_intent_writeback(struct btrfs_fs_info *fs_info, u64 event)
 {
 	struct write_intent_ctrl *ctrl = fs_info->wi_ctrl;
diff --git a/fs/btrfs/write-intent.h b/fs/btrfs/write-intent.h
index 7c0ea3545e89..eafbd3e80c54 100644
--- a/fs/btrfs/write-intent.h
+++ b/fs/btrfs/write-intent.h
@@ -215,6 +215,8 @@ WRITE_INTENT_SETGET_FUNCS(super_blocksize, struct write_intent_super,
 WRITE_INTENT_SETGET_FUNCS(super_csum_type, struct write_intent_super,
 			  csum_type, 16);
 WRITE_INTENT_SETGET_FUNCS(entry_bytenr, struct write_intent_entry, bytenr, 64);
+WRITE_INTENT_SETGET_FUNCS(entry_raw_bitmap, struct write_intent_entry,
+			  bitmap, 64);
 
 static inline u32 write_intent_entry_size(struct write_intent_ctrl *ctrl)
 {
@@ -275,4 +277,12 @@ void btrfs_write_intent_mark_dirty(struct btrfs_fs_info *fs_info, u64 logical,
  */
 void btrfs_write_intent_clear_dirty(struct btrfs_fs_info *fs_info, u64 logical,
 				    u32 len);
+
+/*
+ * Rebuild the range in the write-intent bitmaps.
+ *
+ * Currently not working, it will just output a warning and clear the bitmap.
+ */
+int btrfs_write_intent_recover(struct btrfs_fs_info *fs_info);
+
 #endif
-- 
2.36.1

