md/raid5: consider updating reshape_position at start of reshape. (92140480) · Commits · 戴 / test

md/raid5 only updates ->reshape_position (which is stored in metadata and is authoritative) occasionally, but particularly when getting closed to ->resync_max as it must be correct when ->resync_max is reached. When mdadm tries to stop an array which is reshaping it will: - freeze the reshape, - set resync_max to where the reshape has reached. - unfreeze the reshape. When this happens, the reshape is aborted and then restarted. The restart doesn't check that resync_max is close, and so doesn't update ->reshape_position like it should. This results in the reshape stopping, but ->reshape_position being incorrect. So on that first call to reshape_request, make sure ->reshape_position is updated if needed. Signed-off-by:

NeilBrown <neilb@suse.com>

drivers/md/raid5.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -5347,6 +5347,7 @@ static sector_t reshape_request(struct mddev mddev, sector_t sector_nr, int sk
		sector_t stripe_addr;
		int reshape_sectors;
		struct list_head stripes;
		sector_t retn;

		if (sector_nr == 0) {
		/* If restarting in the middle, skip the initial sectors */
		@@ -5362,7 +5363,8 @@ static sector_t reshape_request(struct mddev mddev, sector_t sector_nr, int sk
		mddev->curr_resync_completed = sector_nr;
		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
		*skipped = 1;
		return sector_nr;
		retn = sector_nr;
		goto finish;
		}
		}

		@@ -5535,6 +5537,8 @@ static sector_t reshape_request(struct mddev mddev, sector_t sector_nr, int sk
		* then we need to write out the superblock.
		*/
		sector_nr += reshape_sectors;
		retn = reshape_sectors;
		finish:
		if ((sector_nr - mddev->curr_resync_completed) * 2
		>= mddev->resync_max - mddev->curr_resync_completed) {
		/* Cannot proceed until we've updated the superblock... */
		@@ -5560,7 +5564,7 @@ static sector_t reshape_request(struct mddev mddev, sector_t sector_nr, int sk
		sysfs_notify(&mddev->kobj, NULL, "sync_completed");
		}
		ret:
		return reshape_sectors;
		return retn;
		}

		static inline sector_t sync_request(struct mddev mddev, sector_t sector_nr, int skipped)

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