Add a SKIP_RESYNC ioctl to md allowing resync to be skipped on an MD device
or partition.
Design note: I expect there to be one (unpartitioned MD device) or just a few
(partitioned MD device) skip_list entries, therefore searching a linked list
is not a huge concern.
Index: linux-2.6.18-128.1.6/drivers/md/md.c
===================================================================
--- linux-2.6.18-128.1.6.orig/drivers/md/md.c
+++ linux-2.6.18-128.1.6/drivers/md/md.c
@@ -314,12 +314,13 @@ static inline int mddev_trylock(mddev_t
return mutex_trylock(&mddev->reconfig_mutex);
}
-static inline void mddev_unlock(mddev_t * mddev)
+inline void mddev_unlock(mddev_t * mddev)
{
mutex_unlock(&mddev->reconfig_mutex);
md_wakeup_thread(mddev->thread);
}
+EXPORT_SYMBOL_GPL(mddev_unlock);
static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
{
@@ -4484,6 +4485,33 @@ static int md_ioctl(struct inode *inode,
err = set_bitmap_file(mddev, (int)arg);
goto done_unlock;
+ case SKIP_RESYNC:
+ {
+ struct hd_struct *part = inode->i_bdev->bd_part;
+ sector_t start, end;
+
+ if (mddev->pers == NULL) {
+ err = -ENODEV;
+ goto abort_unlock;
+ }
+
+ if (mddev->pers->skip_resync == NULL) {
+ err = -EINVAL;
+ goto abort_unlock;
+ }
+
+ if (part) {
+ start = part->start_sect;
+ end = part->start_sect + part->nr_sects - 1;
+ } else {
+ start = 0;
+ end = (mddev->array_size<<1) - 1;
+ }
+
+ err = mddev->pers->skip_resync(mddev, start, end);
+ goto done_unlock;
+ }
+
default:
err = -EINVAL;
goto abort_unlock;
Index: linux-2.6.18-128.1.6/include/linux/raid/md_u.h
===================================================================
--- linux-2.6.18-128.1.6.orig/include/linux/raid/md_u.h
+++ linux-2.6.18-128.1.6/include/linux/raid/md_u.h
@@ -45,6 +45,7 @@
#define STOP_ARRAY _IO (MD_MAJOR, 0x32)
#define STOP_ARRAY_RO _IO (MD_MAJOR, 0x33)
#define RESTART_ARRAY_RW _IO (MD_MAJOR, 0x34)
+#define SKIP_RESYNC _IO (MD_MAJOR, 0x40)
typedef struct mdu_version_s {
int major;
Index: linux-2.6.18-128.1.6/include/linux/raid/md_k.h
===================================================================
--- linux-2.6.18-128.1.6.orig/include/linux/raid/md_k.h
+++ linux-2.6.18-128.1.6/include/linux/raid/md_k.h
@@ -283,6 +283,7 @@ struct mdk_personality
* others - reserved
*/
void (*quiesce) (mddev_t *mddev, int state);
+ int (*skip_resync) (mddev_t *mddev, sector_t start, sector_t end);
};
Index: linux-2.6.18-128.1.6/drivers/md/raid5.c
===================================================================
--- linux-2.6.18-128.1.6.orig/drivers/md/raid5.c
+++ linux-2.6.18-128.1.6/drivers/md/raid5.c
@@ -2827,6 +2827,72 @@ static inline int raid5_redo_bio(raid5_c
return redo;
}
+/*
+ * Mark the range of sectors start-end to be skipped during the current
+ * resync. If no resync is in progress, this will be ignored.
+ */
+static int skip_resync(mddev_t *mddev, sector_t start, sector_t end)
+{
+ struct skip_entry *new;
+ raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
+ unsigned int dd_idx, pd_idx, disks, data_disks;
+
+ if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
+ return 0;
+
+ new = kmalloc(sizeof(*new), GFP_KERNEL);
+ if (new == NULL)
+ return -ENOMEM;
+
+ disks = conf->raid_disks;
+ data_disks = disks - conf->max_degraded;
+
+ new->start = raid5_compute_sector(start, disks, data_disks,
+ &dd_idx, &pd_idx, conf);
+ new->end = raid5_compute_sector(end, disks, data_disks,
+ &dd_idx, &pd_idx, conf);
+ spin_lock_irq(&conf->device_lock);
+ list_add(&new->skip_list, &conf->skip_list);
+ spin_unlock_irq(&conf->device_lock);
+
+ return 0;
+}
+
+/*
+ * Check to see if this sector should be skipped. If so, return the number
+ * of sectors to skip.
+ */
+static sector_t check_skip_list(raid5_conf_t *conf, sector_t sector_nr)
+{
+ struct skip_entry *e;
+
+ list_for_each_entry(e, &conf->skip_list, skip_list) {
+ if (sector_nr >= e->start && sector_nr <= e->end)
+ return (e->end - sector_nr + 1);
+ }
+
+ return 0;
+}
+
+/* Clear the skip list and free associated memory. */
+static void clear_skip_list(raid5_conf_t *conf)
+{
+ struct list_head free_list;
+
+ INIT_LIST_HEAD(&free_list);
+ spin_lock_irq(&conf->device_lock);
+ list_splice_init(&conf->skip_list, &free_list);
+ spin_unlock_irq(&conf->device_lock);
+
+ while (!list_empty(&free_list)) {
+ struct list_head *l = free_list.next;
+ struct skip_entry *e = list_entry(l, struct skip_entry,
+ skip_list);
+ list_del_init(l);
+ kfree(e);
+ }
+}
+
static int make_request(request_queue_t *q, struct bio * bi)
{
mddev_t *mddev = q->queuedata;
@@ -3154,6 +3220,7 @@ static inline sector_t sync_request(mdde
int sync_blocks;
int still_degraded = 0;
int i;
+ sector_t skip_sectors;
if (sector_nr >= max_sector) {
/* just being told to finish up .. nothing much to do */
@@ -3169,6 +3236,7 @@ static inline sector_t sync_request(mdde
else /* completed sync */
conf->fullsync = 0;
bitmap_close_sync(mddev->bitmap);
+ clear_skip_list(conf);
return 0;
}
@@ -3194,6 +3262,13 @@ static inline sector_t sync_request(mdde
*skipped = 1;
return sync_blocks * STRIPE_SECTORS; /* keep things rounded to whole stripes */
}
+ spin_lock_irq(&conf->device_lock);
+ skip_sectors = check_skip_list(conf, sector_nr);
+ spin_unlock_irq(&conf->device_lock);
+ if (skip_sectors) {
+ *skipped = 1;
+ return skip_sectors;
+ }
pd_idx = stripe_to_pdidx(sector_nr, conf, raid_disks);
sh = get_active_stripe(conf, sector_nr, raid_disks, pd_idx, 1);
@@ -3449,6 +3524,7 @@ static int run(mddev_t *mddev)
INIT_LIST_HEAD(&conf->delayed_list);
INIT_LIST_HEAD(&conf->bitmap_list);
INIT_LIST_HEAD(&conf->inactive_list);
+ INIT_LIST_HEAD(&conf->skip_list);
atomic_set(&conf->active_stripes, 0);
atomic_set(&conf->preread_active_stripes, 0);
@@ -4029,6 +4105,7 @@ static struct mdk_personality raid6_pers
.sync_request = sync_request,
.resize = raid5_resize,
.quiesce = raid5_quiesce,
+ .skip_resync = skip_resync,
};
static struct mdk_personality raid5_personality =
{
@@ -4050,6 +4127,7 @@ static struct mdk_personality raid5_pers
.start_reshape = raid5_start_reshape,
#endif
.quiesce = raid5_quiesce,
+ .skip_resync = skip_resync,
};
static struct mdk_personality raid4_personality =
@@ -4068,6 +4146,7 @@ static struct mdk_personality raid4_pers
.sync_request = sync_request,
.resize = raid5_resize,
.quiesce = raid5_quiesce,
+ .skip_resync = skip_resync,
};
static int __init raid5_init(void)
Index: linux-2.6.18-128.1.6/include/linux/raid/raid5.h
===================================================================
--- linux-2.6.18-128.1.6.orig/include/linux/raid/raid5.h
+++ linux-2.6.18-128.1.6/include/linux/raid/raid5.h
@@ -260,6 +260,7 @@ struct raid5_private_data {
int pool_size; /* number of disks in stripeheads in pool */
spinlock_t device_lock;
struct disk_info *disks;
+ struct list_head skip_list; /* used to skip resync on certain blocks */
/*
* Stats
@@ -294,4 +295,11 @@ typedef struct raid5_private_data raid5_
#define ALGORITHM_LEFT_SYMMETRIC 2
#define ALGORITHM_RIGHT_SYMMETRIC 3
+struct skip_entry {
+ struct list_head skip_list;
+
+ sector_t start;
+ sector_t end;
+};
+
#endif
Index: linux-2.6.18-128.1.6/include/linux/raid/md.h
===================================================================
--- linux-2.6.18-128.1.6.orig/include/linux/raid/md.h
+++ linux-2.6.18-128.1.6/include/linux/raid/md.h
@@ -95,5 +95,7 @@ extern void md_new_event(mddev_t *mddev)
extern void md_update_sb(mddev_t * mddev);
+extern void mddev_unlock(mddev_t * mddev);
+
#endif
--
--
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