diff --git a/drivers/md/md-llbitmap.c b/drivers/md/md-llbitmap.c index f10374242c9a..9e7e6b1a6f15 100644 --- a/drivers/md/md-llbitmap.c +++ b/drivers/md/md-llbitmap.c @@ -654,13 +654,73 @@ static int llbitmap_cache_pages(struct llbitmap *llbitmap) return 0; } +/* + * Check if all underlying disks support write_zeroes with unmap. + */ +static bool llbitmap_all_disks_support_wzeroes_unmap(struct llbitmap *llbitmap) +{ + struct mddev *mddev = llbitmap->mddev; + struct md_rdev *rdev; + + rdev_for_each(rdev, mddev) { + if (rdev->raid_disk < 0 || test_bit(Faulty, &rdev->flags)) + continue; + + if (bdev_write_zeroes_unmap_sectors(rdev->bdev) == 0) + return false; + } + + return true; +} + +/* + * Issue write_zeroes to all underlying disks to zero their data regions. + * This ensures parity consistency for RAID-456 (0 XOR 0 = 0). + * Returns true if all disks were successfully zeroed. + */ +static bool llbitmap_zero_all_disks(struct llbitmap *llbitmap) +{ + struct mddev *mddev = llbitmap->mddev; + struct md_rdev *rdev; + sector_t dev_sectors = mddev->dev_sectors; + int ret; + + rdev_for_each(rdev, mddev) { + if (rdev->raid_disk < 0 || test_bit(Faulty, &rdev->flags)) + continue; + + ret = blkdev_issue_zeroout(rdev->bdev, + rdev->data_offset, + dev_sectors, + GFP_KERNEL, 0); + if (ret) { + pr_warn("md/llbitmap: failed to zero disk %pg: %d\n", + rdev->bdev, ret); + return false; + } + } + + return true; +} + static void llbitmap_init_state(struct llbitmap *llbitmap) { + struct mddev *mddev = llbitmap->mddev; enum llbitmap_state state = BitUnwritten; unsigned long i; - if (test_and_clear_bit(BITMAP_CLEAN, &llbitmap->flags)) + if (test_and_clear_bit(BITMAP_CLEAN, &llbitmap->flags)) { state = BitClean; + } else if (raid_is_456(mddev) && + llbitmap_all_disks_support_wzeroes_unmap(llbitmap)) { + /* + * All disks support write_zeroes with unmap. Zero all disks + * to ensure parity consistency, then set BitCleanUnwritten + * to skip initial sync. + */ + if (llbitmap_zero_all_disks(llbitmap)) + state = BitCleanUnwritten; + } for (i = 0; i < llbitmap->chunks; i++) llbitmap_write(llbitmap, state, i);