Merge tag 'for-6.4-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A  more fixes and regression fixes:

   - in subpage mode, fix crash when repairing metadata at the end of
     a stripe

   - properly enable async discard when remounting from read-only to
     read-write

   - scrub regression fixes:
      - respect read-only scrub when attempting to do a repair
      - fix reporting of found errors, the stats don't get properly
        accounted after a stripe repair"

* tag 'for-6.4-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: scrub: also report errors hit during the initial read
  btrfs: scrub: respect the read-only flag during repair
  btrfs: properly enable async discard when switching from RO->RW
  btrfs: subpage: fix a crash in metadata repair path

fs/btrfs/disk-io.c

@@ -242,7 +242,6 @@ static int btrfs_repair_eb_io_failure(const struct extent_buffer *eb,
 				      int mirror_num)
 {
 	struct btrfs_fs_info *fs_info = eb->fs_info;
-	u64 start = eb->start;
 	int i, num_pages = num_extent_pages(eb);
 	int ret = 0;
 
@@ -251,12 +250,14 @@ static int btrfs_repair_eb_io_failure(const struct extent_buffer *eb,
 
 	for (i = 0; i < num_pages; i++) {
 		struct page *p = eb->pages[i];
+		u64 start = max_t(u64, eb->start, page_offset(p));
+		u64 end = min_t(u64, eb->start + eb->len, page_offset(p) + PAGE_SIZE);
+		u32 len = end - start;
 
-		ret = btrfs_repair_io_failure(fs_info, 0, start, PAGE_SIZE,
-				start, p, start - page_offset(p), mirror_num);
+		ret = btrfs_repair_io_failure(fs_info, 0, start, len,
+				start, p, offset_in_page(start), mirror_num);
 		if (ret)
 			break;
-		start += PAGE_SIZE;
 	}
 
 	return ret;

fs/btrfs/scrub.c

@@ -134,8 +134,14 @@ struct scrub_stripe {
 	 * The errors hit during the initial read of the stripe.
 	 *
 	 * Would be utilized for error reporting and repair.
+	 *
+	 * The remaining init_nr_* records the number of errors hit, only used
+	 * by error reporting.
 	 */
 	unsigned long init_error_bitmap;
+	unsigned int init_nr_io_errors;
+	unsigned int init_nr_csum_errors;
+	unsigned int init_nr_meta_errors;
 
 	/*
 	 * The following error bitmaps are all for the current status.
@@ -1003,12 +1009,9 @@ static void scrub_stripe_report_errors(struct scrub_ctx *sctx,
 	sctx->stat.data_bytes_scrubbed += nr_data_sectors << fs_info->sectorsize_bits;
 	sctx->stat.tree_bytes_scrubbed += nr_meta_sectors << fs_info->sectorsize_bits;
 	sctx->stat.no_csum += nr_nodatacsum_sectors;
-	sctx->stat.read_errors +=
-		bitmap_weight(&stripe->io_error_bitmap, stripe->nr_sectors);
-	sctx->stat.csum_errors +=
-		bitmap_weight(&stripe->csum_error_bitmap, stripe->nr_sectors);
-	sctx->stat.verify_errors +=
-		bitmap_weight(&stripe->meta_error_bitmap, stripe->nr_sectors);
+	sctx->stat.read_errors += stripe->init_nr_io_errors;
+	sctx->stat.csum_errors += stripe->init_nr_csum_errors;
+	sctx->stat.verify_errors += stripe->init_nr_meta_errors;
 	sctx->stat.uncorrectable_errors +=
 		bitmap_weight(&stripe->error_bitmap, stripe->nr_sectors);
 	sctx->stat.corrected_errors += nr_repaired_sectors;
@@ -1041,6 +1044,12 @@ static void scrub_stripe_read_repair_worker(struct work_struct *work)
 	scrub_verify_one_stripe(stripe, stripe->extent_sector_bitmap);
 	/* Save the initial failed bitmap for later repair and report usage. */
 	stripe->init_error_bitmap = stripe->error_bitmap;
+	stripe->init_nr_io_errors = bitmap_weight(&stripe->io_error_bitmap,
+						  stripe->nr_sectors);
+	stripe->init_nr_csum_errors = bitmap_weight(&stripe->csum_error_bitmap,
+						    stripe->nr_sectors);
+	stripe->init_nr_meta_errors = bitmap_weight(&stripe->meta_error_bitmap,
+						    stripe->nr_sectors);
 
 	if (bitmap_empty(&stripe->init_error_bitmap, stripe->nr_sectors))
 		goto out;
@@ -1490,6 +1499,9 @@ static void scrub_stripe_reset_bitmaps(struct scrub_stripe *stripe)
 {
 	stripe->extent_sector_bitmap = 0;
 	stripe->init_error_bitmap = 0;
+	stripe->init_nr_io_errors = 0;
+	stripe->init_nr_csum_errors = 0;
+	stripe->init_nr_meta_errors = 0;
 	stripe->error_bitmap = 0;
 	stripe->io_error_bitmap = 0;
 	stripe->csum_error_bitmap = 0;
@@ -1730,7 +1742,7 @@ static int flush_scrub_stripes(struct scrub_ctx *sctx)
 				break;
 			}
 		}
-	} else {
+	} else if (!sctx->readonly) {
 		for (int i = 0; i < nr_stripes; i++) {
 			unsigned long repaired;
 

fs/btrfs/super.c

@@ -1841,6 +1841,12 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 		btrfs_clear_sb_rdonly(sb);
 
 		set_bit(BTRFS_FS_OPEN, &fs_info->flags);
+
+		/*
+		 * If we've gone from readonly -> read/write, we need to get
+		 * our sync/async discard lists in the right state.
+		 */
+		btrfs_discard_resume(fs_info);
 	}
 out:
 	/*