[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 <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index d3a64a0..51d9645 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -893,7 +893,6 @@
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 @@
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 @@
int i;
int write_targets = 0;
int sync_blocks;
+ int still_degraded = 0;
if (!conf->r1buf_pool)
{
@@ -1137,7 +1136,10 @@
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 @@
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 @@
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))