From: NeilBrown Date: Thu, 4 Aug 2005 19:53:34 +0000 (-0700) Subject: [PATCH] md: yet another attempt to get bitmap-based resync to do the right thing... X-Git-Tag: v2.6.13-rc6~59 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=e3b9703e27aab3839dcdb76b00d98428b67d25b0;p=linux-2.6-omap-h63xx.git [PATCH] md: yet another attempt to get bitmap-based resync to do the right thing in all cases... Firstly, R1BIO_Degraded was being set in a number of places in the resync code, but is never used there, so get rid of those settings. Then: When doing a resync, we want to clear the bit in the bitmap iff the array will be non-degraded when the sync has completed. However the current code would clear the bitmap if the array was non-degraded when the resync *started*, which obviously isn't right (it is for 'resync' but not for 'recovery' - i.e. rebuilding a failed drive). This patch calculated 'still_degraded' and uses the to tell bitmap_start_sync whether this sync should clear the corresponding bit. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index d3a64a04a6d..51d9645ed09 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -893,7 +893,6 @@ static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error) if (!uptodate) { md_error(r1_bio->mddev, conf->mirrors[r1_bio->read_disk].rdev); - set_bit(R1BIO_Degraded, &r1_bio->state); } else set_bit(R1BIO_Uptodate, &r1_bio->state); rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev); @@ -918,10 +917,9 @@ static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error) mirror = i; break; } - if (!uptodate) { + if (!uptodate) md_error(mddev, conf->mirrors[mirror].rdev); - set_bit(R1BIO_Degraded, &r1_bio->state); - } + update_head_pos(mirror, r1_bio); if (atomic_dec_and_test(&r1_bio->remaining)) { @@ -1109,6 +1107,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i int i; int write_targets = 0; int sync_blocks; + int still_degraded = 0; if (!conf->r1buf_pool) { @@ -1137,7 +1136,10 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i return 0; } - if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, mddev->degraded) && + /* before building a request, check if we can skip these blocks.. + * This call the bitmap_start_sync doesn't actually record anything + */ + if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && !conf->fullsync) { /* We can skip this block, and probably several more */ *skipped = 1; @@ -1203,24 +1205,23 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i if (i == disk) { bio->bi_rw = READ; bio->bi_end_io = end_sync_read; - } else if (conf->mirrors[i].rdev && - !conf->mirrors[i].rdev->faulty && - (!conf->mirrors[i].rdev->in_sync || - sector_nr + RESYNC_SECTORS > mddev->recovery_cp)) { + } else if (conf->mirrors[i].rdev == NULL || + conf->mirrors[i].rdev->faulty) { + still_degraded = 1; + continue; + } else if (!conf->mirrors[i].rdev->in_sync || + sector_nr + RESYNC_SECTORS > mddev->recovery_cp) { bio->bi_rw = WRITE; bio->bi_end_io = end_sync_write; write_targets ++; } else + /* no need to read or write here */ continue; bio->bi_sector = sector_nr + conf->mirrors[i].rdev->data_offset; bio->bi_bdev = conf->mirrors[i].rdev->bdev; bio->bi_private = r1_bio; } - if (write_targets + 1 < conf->raid_disks) - /* array degraded, can't clear bitmap */ - set_bit(R1BIO_Degraded, &r1_bio->state); - if (write_targets == 0) { /* There is nowhere to write, so all non-sync * drives must be failed - so we are finished @@ -1243,7 +1244,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i break; if (sync_blocks == 0) { if (!bitmap_start_sync(mddev->bitmap, sector_nr, - &sync_blocks, mddev->degraded) && + &sync_blocks, still_degraded) && !conf->fullsync) break; if (sync_blocks < (PAGE_SIZE>>9))