The patch titled
md: Allow re-add to work on array without bitmaps
has been added to the -mm tree. Its filename is
md-allow-re-add-to-work-on-array-without-bitmaps.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: md: Allow re-add to work on array without bitmaps
From: NeilBrown <neilb@xxxxxxx>
When an array has a bitmap, a device can be removed and re-added and only
blocks changes since the removal (as recorded in the bitmap) will be resynced.
It should be possible to do a similar thing to arrays without bitmaps. i.e.
if a device is removed and re-added and *no* changes have been made in the
interim, then the add should not require a resync.
This patch allows that option. This means that when assembling an array one
device at a time (e.g. during device discovery) the array can be enabled
read-only as soon as enough devices are available, but extra devices can still
be added without causing a resync.
Signed-off-by: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/md/md.c | 25 ++++++++++++++-----------
drivers/md/raid1.c | 6 ++++++
2 files changed, 20 insertions(+), 11 deletions(-)
diff -puN drivers/md/md.c~md-allow-re-add-to-work-on-array-without-bitmaps drivers/md/md.c
--- devel/drivers/md/md.c~md-allow-re-add-to-work-on-array-without-bitmaps 2006-05-31 22:28:14.000000000 -0700
+++ devel-akpm/drivers/md/md.c 2006-05-31 22:28:14.000000000 -0700
@@ -737,6 +737,7 @@ static int super_90_validate(mddev_t *md
{
mdp_disk_t *desc;
mdp_super_t *sb = (mdp_super_t *)page_address(rdev->sb_page);
+ __u64 ev1 = md_event(sb);
rdev->raid_disk = -1;
rdev->flags = 0;
@@ -753,7 +754,7 @@ static int super_90_validate(mddev_t *md
mddev->layout = sb->layout;
mddev->raid_disks = sb->raid_disks;
mddev->size = sb->size;
- mddev->events = md_event(sb);
+ mddev->events = ev1;
mddev->bitmap_offset = 0;
mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
@@ -802,7 +803,6 @@ static int super_90_validate(mddev_t *md
} else if (mddev->pers == NULL) {
/* Insist on good event counter while assembling */
- __u64 ev1 = md_event(sb);
++ev1;
if (ev1 < mddev->events)
return -EINVAL;
@@ -810,11 +810,13 @@ static int super_90_validate(mddev_t *md
/* if adding to array with a bitmap, then we can accept an
* older device ... but not too old.
*/
- __u64 ev1 = md_event(sb);
if (ev1 < mddev->bitmap->events_cleared)
return 0;
- } else /* just a hot-add of a new device, leave raid_disk at -1 */
- return 0;
+ } else {
+ if (ev1 < mddev->events)
+ /* just a hot-add of a new device, leave raid_disk at -1 */
+ return 0;
+ }
if (mddev->level != LEVEL_MULTIPATH) {
desc = sb->disks + rdev->desc_nr;
@@ -1105,6 +1107,7 @@ static int super_1_load(mdk_rdev_t *rdev
static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
{
struct mdp_superblock_1 *sb = (struct mdp_superblock_1*)page_address(rdev->sb_page);
+ __u64 ev1 = le64_to_cpu(sb->events);
rdev->raid_disk = -1;
rdev->flags = 0;
@@ -1120,7 +1123,7 @@ static int super_1_validate(mddev_t *mdd
mddev->layout = le32_to_cpu(sb->layout);
mddev->raid_disks = le32_to_cpu(sb->raid_disks);
mddev->size = le64_to_cpu(sb->size)/2;
- mddev->events = le64_to_cpu(sb->events);
+ mddev->events = ev1;
mddev->bitmap_offset = 0;
mddev->default_bitmap_offset = 1024 >> 9;
@@ -1154,7 +1157,6 @@ static int super_1_validate(mddev_t *mdd
} else if (mddev->pers == NULL) {
/* Insist of good event counter while assembling */
- __u64 ev1 = le64_to_cpu(sb->events);
++ev1;
if (ev1 < mddev->events)
return -EINVAL;
@@ -1162,12 +1164,13 @@ static int super_1_validate(mddev_t *mdd
/* If adding to array with a bitmap, then we can accept an
* older device, but not too old.
*/
- __u64 ev1 = le64_to_cpu(sb->events);
if (ev1 < mddev->bitmap->events_cleared)
return 0;
- } else /* just a hot-add of a new device, leave raid_disk at -1 */
- return 0;
-
+ } else {
+ if (ev1 < mddev->events)
+ /* just a hot-add of a new device, leave raid_disk at -1 */
+ return 0;
+ }
if (mddev->level != LEVEL_MULTIPATH) {
int role;
rdev->desc_nr = le32_to_cpu(sb->dev_number);
diff -puN drivers/md/raid1.c~md-allow-re-add-to-work-on-array-without-bitmaps drivers/md/raid1.c
--- devel/drivers/md/raid1.c~md-allow-re-add-to-work-on-array-without-bitmaps 2006-05-31 22:28:14.000000000 -0700
+++ devel-akpm/drivers/md/raid1.c 2006-05-31 22:28:14.000000000 -0700
@@ -1625,6 +1625,12 @@ static sector_t sync_request(mddev_t *md
/* before building a request, check if we can skip these blocks..
* This call the bitmap_start_sync doesn't actually record anything
*/
+ if (mddev->bitmap == NULL &&
+ mddev->recovery_cp == MaxSector &&
+ conf->fullsync == 0) {
+ *skipped = 1;
+ return max_sector - sector_nr;
+ }
if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
!conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
/* We can skip this block, and probably several more */
_
Patches currently in -mm which might be from neilb@xxxxxxx are
origin.patch
fix-dcache-race-during-umount.patch
prune_one_dentry-tweaks.patch
remove-softlockup-from-invalidate_mapping_pages.patch
prepare-for-__copy_from_user_inatomic-to-not-zero-missed-bytes.patch
make-copy_from_user_inatomic-not-zero-the-tail-on-i386.patch
kconfig-select-things-at-the-closest-tristate-instead-of-bool.patch
dm-mirror-sector-offset-fix.patch
md-reformat-code-in-raid1_end_write_request-to-avoid-goto.patch
md-remove-arbitrary-limit-on-chunk-size.patch
md-remove-useless-ioctl-warning.patch
md-increase-the-delay-before-marking-metadata-clean-and-make-it-configurable.patch
md-merge-raid5-and-raid6-code.patch
md-remove-nuisance-message-at-shutdown.patch
md-allow-checkpoint-of-recovery-with-version-1-superblock.patch
md-allow-checkpoint-of-recovery-with-version-1-superblock-fix.patch
md-allow-a-linear-array-to-have-drives-added-while-active.patch
md-support-stripe-offset-mode-in-raid10.patch
md-make-md_print_devices-static.patch
md-split-reshape-portion-of-raid5-sync_request-into-a-separate-function.patch
md-bitmap-fix-online-removal-of-file-backed-bitmaps.patch
md-bitmap-remove-bitmap-writeback-daemon.patch
md-bitmap-cleaner-separation-of-page-attribute-handlers-in-md-bitmap.patch
md-bitmap-use-set_bit-etc-for-bitmap-page-attributes.patch
md-bitmap-remove-unnecessary-page-reference-manipulations-from-md-bitmap-code.patch
md-bitmap-remove-dead-code-from-md-bitmap.patch
md-bitmap-tidy-up-i_writecount-handling-in-md-bitmap.patch
md-bitmap-change-md-bitmap-file-handling-to-use-bmap-to-file-blocks.patch
md-change-md-bitmap-file-handling-to-use-bmap-to-file-blocks-fix.patch
md-calculate-correct-array-size-for-raid10-in-new-offset-mode.patch
md-md-kconfig-speeling-feex.patch
md-fix-kconfig-error.patch
md-fix-bug-that-stops-raid5-resync-from-happening.patch
md-allow-re-add-to-work-on-array-without-bitmaps.patch
md-dont-write-dirty-clean-update-to-spares-leave-them-alone.patch
md-set-get-state-of-array-via-sysfs.patch
md-allow-rdev-state-to-be-set-via-sysfs.patch
md-allow-raid-layout-to-be-read-and-set-via-sysfs.patch
md-allow-resync_start-to-be-set-and-queried-via-sysfs.patch
md-allow-the-write_mostly-flag-to-be-set-via-sysfs.patch
md-dm-reduce-stack-usage-with-stacked-block-devices.patch
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