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authorNeilBrown <neilb@suse.de>2009-03-30 23:56:41 -0400
committerNeilBrown <neilb@suse.de>2009-03-30 23:56:41 -0400
commitb3546035277847028df650b147469fc943cf5c71 (patch)
tree87966abc5456a62845326eb8d5a5cf0f88879b2d /drivers/md
parentd562b0c4313e3ddea402a400371afa47ddf679f9 (diff)
md/raid5: allow layout/chunksize to be changed on an active 2-drive raid5.
2-drive raid5's aren't very interesting. But if you are converting a raid1 into a raid5, you will at least temporarily have one. And that it a good time to set the layout/chunksize for the new RAID5 if you aren't happy with the defaults. layout and chunksize don't actually affect the placement of data on a 2-drive raid5, so we just do some internal book-keeping. Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/md.c37
-rw-r--r--drivers/md/raid5.c42
2 files changed, 66 insertions, 13 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 05b613b5e4b2..0689d89d263c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2771,12 +2771,18 @@ layout_store(mddev_t *mddev, const char *buf, size_t len)
2771 if (!*buf || (*e && *e != '\n')) 2771 if (!*buf || (*e && *e != '\n'))
2772 return -EINVAL; 2772 return -EINVAL;
2773 2773
2774 if (mddev->pers) 2774 if (mddev->pers) {
2775 return -EBUSY; 2775 int err;
2776 2776 if (mddev->pers->reconfig == NULL)
2777 mddev->new_layout = n; 2777 return -EBUSY;
2778 if (mddev->reshape_position == MaxSector) 2778 err = mddev->pers->reconfig(mddev, n, -1);
2779 mddev->layout = n; 2779 if (err)
2780 return err;
2781 } else {
2782 mddev->new_layout = n;
2783 if (mddev->reshape_position == MaxSector)
2784 mddev->layout = n;
2785 }
2780 return len; 2786 return len;
2781} 2787}
2782static struct md_sysfs_entry md_layout = 2788static struct md_sysfs_entry md_layout =
@@ -2833,19 +2839,24 @@ chunk_size_show(mddev_t *mddev, char *page)
2833static ssize_t 2839static ssize_t
2834chunk_size_store(mddev_t *mddev, const char *buf, size_t len) 2840chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
2835{ 2841{
2836 /* can only set chunk_size if array is not yet active */
2837 char *e; 2842 char *e;
2838 unsigned long n = simple_strtoul(buf, &e, 10); 2843 unsigned long n = simple_strtoul(buf, &e, 10);
2839 2844
2840 if (!*buf || (*e && *e != '\n')) 2845 if (!*buf || (*e && *e != '\n'))
2841 return -EINVAL; 2846 return -EINVAL;
2842 2847
2843 if (mddev->pers) 2848 if (mddev->pers) {
2844 return -EBUSY; 2849 int err;
2845 2850 if (mddev->pers->reconfig == NULL)
2846 mddev->new_chunk = n; 2851 return -EBUSY;
2847 if (mddev->reshape_position == MaxSector) 2852 err = mddev->pers->reconfig(mddev, -1, n);
2848 mddev->chunk_size = n; 2853 if (err)
2854 return err;
2855 } else {
2856 mddev->new_chunk = n;
2857 if (mddev->reshape_position == MaxSector)
2858 mddev->chunk_size = n;
2859 }
2849 return len; 2860 return len;
2850} 2861}
2851static struct md_sysfs_entry md_chunk_size = 2862static struct md_sysfs_entry md_chunk_size =
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 611ea7bbf474..8a5e14e4a851 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -4913,6 +4913,47 @@ static void *raid5_takeover_raid1(mddev_t *mddev)
4913} 4913}
4914 4914
4915 4915
4916static int raid5_reconfig(mddev_t *mddev, int new_layout, int new_chunk)
4917{
4918 /* Currently the layout and chunk size can only be changed
4919 * for a 2-drive raid array, as in that case no data shuffling
4920 * is required.
4921 * Later we might validate these and set new_* so a reshape
4922 * can complete the change.
4923 */
4924 raid5_conf_t *conf = mddev_to_conf(mddev);
4925
4926 if (new_layout >= 0 && !algorithm_valid_raid5(new_layout))
4927 return -EINVAL;
4928 if (new_chunk > 0) {
4929 if (new_chunk & (new_chunk-1))
4930 /* not a power of 2 */
4931 return -EINVAL;
4932 if (new_chunk < PAGE_SIZE)
4933 return -EINVAL;
4934 if (mddev->array_sectors & ((new_chunk>>9)-1))
4935 /* not factor of array size */
4936 return -EINVAL;
4937 }
4938
4939 /* They look valid */
4940
4941 if (mddev->raid_disks != 2)
4942 return -EINVAL;
4943
4944 if (new_layout >= 0) {
4945 conf->algorithm = new_layout;
4946 mddev->layout = mddev->new_layout = new_layout;
4947 }
4948 if (new_chunk > 0) {
4949 conf->chunk_size = new_chunk;
4950 mddev->chunk_size = mddev->new_chunk = new_chunk;
4951 }
4952 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4953 md_wakeup_thread(mddev->thread);
4954 return 0;
4955}
4956
4916static void *raid5_takeover(mddev_t *mddev) 4957static void *raid5_takeover(mddev_t *mddev)
4917{ 4958{
4918 /* raid5 can take over: 4959 /* raid5 can take over:
@@ -5023,6 +5064,7 @@ static struct mdk_personality raid5_personality =
5023#endif 5064#endif
5024 .quiesce = raid5_quiesce, 5065 .quiesce = raid5_quiesce,
5025 .takeover = raid5_takeover, 5066 .takeover = raid5_takeover,
5067 .reconfig = raid5_reconfig,
5026}; 5068};
5027 5069
5028static struct mdk_personality raid4_personality = 5070static struct mdk_personality raid4_personality =