From 4aaf7694f841edc96fe0f72958aabe59204b3611 Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Tue, 4 Jul 2017 11:20:30 +0800 Subject: [PATCH] md/bitmap: don't read page from device with Bitmap_sync The device owns Bitmap_sync flag needs recovery to become in sync, and read page from this type device could get stale status. Also add comments for Bitmap_sync bit per the suggestion from Shaohua and Neil. Previous disscussion can be found here: https://marc.info/?t=149760428900004&r=1&w=2 Signed-off-by: Guoqing Jiang Signed-off-by: Shaohua Li --- drivers/md/bitmap.c | 3 ++- drivers/md/md.h | 4 +++- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index f4eace5ea184..40f3cd7eab0f 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -156,7 +156,8 @@ static int read_sb_page(struct mddev *mddev, loff_t offset, rdev_for_each(rdev, mddev) { if (! test_bit(In_sync, &rdev->flags) - || test_bit(Faulty, &rdev->flags)) + || test_bit(Faulty, &rdev->flags) + || test_bit(Bitmap_sync, &rdev->flags)) continue; target = offset + index * (PAGE_SIZE/512); diff --git a/drivers/md/md.h b/drivers/md/md.h index 991f0fe2dcc6..b50eb4ac1b82 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -134,7 +134,9 @@ enum flag_bits { Faulty, /* device is known to have a fault */ In_sync, /* device is in_sync with rest of array */ Bitmap_sync, /* ..actually, not quite In_sync. Need a - * bitmap-based recovery to get fully in sync + * bitmap-based recovery to get fully in sync. + * The bit is only meaningful before device + * has been passed to pers->hot_add_disk. */ WriteMostly, /* Avoid reading if at all possible */ AutoDetected, /* added by auto-detect */