From d9c0fa509eafb31605bddda34e2e39f4354563b6 Mon Sep 17 00:00:00 2001 From: Xiao Ni Date: Tue, 30 Jun 2020 15:55:36 +0800 Subject: [PATCH] md: fix max sectors calculation for super 1.0 To grow size of super 1.0 raid array, it is necessary to check the device max usable size. Now it uses rdev->sectors for max usable size. If one disk is 500G and the raid device only uses the 100GB of this disk. rdev->sectors can't tell the real max usable size. The max usable size should be dev_size-(superblock_size+bitmap_size+badblock_size). Also, remove unnecessary sb_start update in super_1_rdev_size_change(). Signed-off-by: Xiao Ni Signed-off-by: Song Liu --- drivers/md/md.c | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index ea48bc2..5e8f772 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2193,6 +2193,24 @@ retry: sb->sb_csum = calc_sb_1_csum(sb); } +static sector_t super_1_choose_bm_space(sector_t dev_size) +{ + sector_t bm_space; + + /* if the device is bigger than 8Gig, save 64k for bitmap + * usage, if bigger than 200Gig, save 128k + */ + if (dev_size < 64*2) + bm_space = 0; + else if (dev_size - 64*2 >= 200*1024*1024*2) + bm_space = 128*2; + else if (dev_size - 4*2 > 8*1024*1024*2) + bm_space = 64*2; + else + bm_space = 4*2; + return bm_space; +} + static unsigned long long super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors) { @@ -2213,13 +2231,22 @@ super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors) return 0; } else { /* minor version 0; superblock after data */ - sector_t sb_start; - sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2; + sector_t sb_start, bm_space; + sector_t dev_size = i_size_read(rdev->bdev->bd_inode) >> 9; + + /* 8K is for superblock */ + sb_start = dev_size - 8*2; sb_start &= ~(sector_t)(4*2 - 1); - max_sectors = rdev->sectors + sb_start - rdev->sb_start; + + bm_space = super_1_choose_bm_space(dev_size); + + /* Space that can be used to store date needs to decrease + * superblock bitmap space and bad block space(4K) + */ + max_sectors = sb_start - bm_space - 4*2; + if (!num_sectors || num_sectors > max_sectors) num_sectors = max_sectors; - rdev->sb_start = sb_start; } sb = page_address(rdev->sb_page); sb->data_size = cpu_to_le64(num_sectors); -- 2.7.4