From: Yu Kuai <yukuai3@huawei.com> mainline inclusion from mainline-v6.9-rc1 commit 9f3ced792203891b8fa39afa37908eba843fcfac category: bugfix bugzilla: 190197 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- read_balance() is hard to understand because there are too many status and branches, and it's overlong. This patch factor out the case to read the rdev with bad blocks from read_balance(), there are no functional changes. Co-developed-by: Paul Luse <paul.e.luse@linux.intel.com> Signed-off-by: Paul Luse <paul.e.luse@linux.intel.com> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Xiao Ni <xni@redhat.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240229095714.926789-10-yukuai1@huaweicloud.com Signed-off-by: Li Nan <linan122@huawei.com> --- drivers/md/raid1.c | 79 ++++++++++++++++++++++++++++------------------ 1 file changed, 48 insertions(+), 31 deletions(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 42879db48fd5..78173321d099 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -616,6 +616,44 @@ static int choose_first_rdev(struct r1conf *conf, struct r1bio *r1_bio, return -1; } +static int choose_bb_rdev(struct r1conf *conf, struct r1bio *r1_bio, + int *max_sectors) +{ + sector_t this_sector = r1_bio->sector; + int best_disk = -1; + int best_len = 0; + int disk; + + for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) { + struct md_rdev *rdev; + int len; + int read_len; + + if (r1_bio->bios[disk] == IO_BLOCKED) + continue; + + rdev = conf->mirrors[disk].rdev; + if (!rdev || test_bit(Faulty, &rdev->flags) || + test_bit(WriteMostly, &rdev->flags)) + continue; + + /* keep track of the disk with the most readable sectors. */ + len = r1_bio->sectors; + read_len = raid1_check_read_range(rdev, this_sector, &len); + if (read_len > best_len) { + best_disk = disk; + best_len = read_len; + } + } + + if (best_disk != -1) { + *max_sectors = best_len; + update_read_sectors(conf, best_disk, this_sector, best_len); + } + + return best_disk; +} + static int choose_slow_rdev(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors) { @@ -704,8 +742,6 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) { sector_t dist; - sector_t first_bad; - int bad_sectors; unsigned int pending; rdev = conf->mirrors[disk].rdev; @@ -718,36 +754,8 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect continue; if (test_bit(WriteMostly, &rdev->flags)) continue; - /* This is a reasonable device to use. It might - * even be best. - */ - if (is_badblock(rdev, this_sector, sectors, - &first_bad, &bad_sectors)) { - if (best_dist < MaxSector) - /* already have a better device */ - continue; - if (first_bad <= this_sector) { - /* cannot read here. If this is the 'primary' - * device, then we must not read beyond - * bad_sectors from another device.. - */ - bad_sectors -= (this_sector - first_bad); - if (best_good_sectors > sectors) - best_good_sectors = sectors; - - } else { - sector_t good_sectors = first_bad - this_sector; - if (good_sectors > best_good_sectors) { - best_good_sectors = good_sectors; - best_disk = disk; - } - } + if (rdev_has_badblock(rdev, this_sector, sectors)) continue; - } else { - if ((sectors > best_good_sectors) && (best_disk >= 0)) - best_disk = -1; - best_good_sectors = sectors; - } if (best_disk >= 0) /* At least two disks to choose from so failfast is OK */ @@ -839,6 +847,15 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect if (best_disk >= 0) return best_disk; + /* + * If we are here it means we didn't find a perfectly good disk so + * now spend a bit more time trying to find one with the most good + * sectors. + */ + disk = choose_bb_rdev(conf, r1_bio, max_sectors); + if (disk >= 0) + return disk; + return choose_slow_rdev(conf, r1_bio, max_sectors); } -- 2.39.2