Commit d9dd26b2 authored by Shaohua Li's avatar Shaohua Li
Browse files

MD: hold mddev lock to change bitmap location 



Changing the location changes a lot of things. Holding the lock to avoid race.
This makes the .quiesce called with mddev lock hold too.

Acked-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent ff00d3b4

drivers/md/bitmap.c

+33 −14
Original line number Diff line number Diff line
@@ -2183,19 +2183,29 @@ location_show(struct mddev *mddev, char *page) 
static ssize_t

location_store(struct mddev *mddev, const char *buf, size_t len)

{

	int rv;



	rv = mddev_lock(mddev);

	if (rv)

		return rv;

	if (mddev->pers) {

		if (!mddev->pers->quiesce)

			return -EBUSY;

		if (mddev->recovery || mddev->sync_thread)

			return -EBUSY;

		if (!mddev->pers->quiesce) {

			rv = -EBUSY;

			goto out;

		}

		if (mddev->recovery || mddev->sync_thread) {

			rv = -EBUSY;

			goto out;

		}

	}



	if (mddev->bitmap || mddev->bitmap_info.file ||

	    mddev->bitmap_info.offset) {

		/* bitmap already configured.  Only option is to clear it */

		if (strncmp(buf, "none", 4) != 0)

			return -EBUSY;

		if (strncmp(buf, "none", 4) != 0) {

			rv = -EBUSY;

			goto out;

		}

		if (mddev->pers) {

			mddev->pers->quiesce(mddev, 1);

			bitmap_destroy(mddev);
@@ -2214,21 +2224,25 @@ location_store(struct mddev *mddev, const char *buf, size_t len) 
			/* nothing to be done */;

		else if (strncmp(buf, "file:", 5) == 0) {

			/* Not supported yet */

			return -EINVAL;

			rv = -EINVAL;

			goto out;

		} else {

			int rv;

			if (buf[0] == '+')

				rv = kstrtoll(buf+1, 10, &offset);

			else

				rv = kstrtoll(buf, 10, &offset);

			if (rv)

				return rv;

			if (offset == 0)

				return -EINVAL;

				goto out;

			if (offset == 0) {

				rv = -EINVAL;

				goto out;

			}

			if (mddev->bitmap_info.external == 0 &&

			    mddev->major_version == 0 &&

			    offset != mddev->bitmap_info.default_offset)

				return -EINVAL;

			    offset != mddev->bitmap_info.default_offset) {

				rv = -EINVAL;

				goto out;

			}

			mddev->bitmap_info.offset = offset;

			if (mddev->pers) {

				struct bitmap *bitmap;
@@ -2245,7 +2259,7 @@ location_store(struct mddev *mddev, const char *buf, size_t len) 
				mddev->pers->quiesce(mddev, 0);

				if (rv) {

					bitmap_destroy(mddev);

					return rv;

					goto out;

				}

			}

		}
@@ -2257,6 +2271,11 @@ location_store(struct mddev *mddev, const char *buf, size_t len) 
		set_bit(MD_CHANGE_DEVS, &mddev->flags);

		md_wakeup_thread(mddev->thread);

	}

	rv = 0;

out:

	mddev_unlock(mddev);

	if (rv)

		return rv;

	return len;

}