Re: [dm-devel] [PATCH] dm: noflush resizing (0/3)

Jun'ichi Nomura
2007-10-25T23:51:53Z

Alasdair,

Jun'ichi Nomura wrote:
> So as far as I understand, the point is:
> 1. it's preferable to resize inode after the resume, if possible

Attached is a modified version of the (2/3) patch.
- The logic is basically the same as before.
- Moved the set-size function outside of the table swapping.
- Moved the uevent to the end of resize from the end of resume.
- Lightly tested on LVM2 mirror resizing.
- (1/3) and (3/3) are unchanged.

What do you think about this?

---
drivers/md/dm-ioctl.c | 4 ++
drivers/md/dm.c | 61 ++++++++++++++++++++++++++----------------
include/linux/device-mapper.h | 5 +++
3 files changed, 46 insertions(+), 24 deletions(-)

Index: linux-2.6.23.work/drivers/md/dm.c
===================================================================
--- linux-2.6.23.work.orig/drivers/md/dm.c
+++ linux-2.6.23.work/drivers/md/dm.c
@@ -1099,31 +1099,11 @@ static void event_callback(void *context
wake_up(&md->eventq);
}

-static void __set_size(struct mapped_device *md, sector_t size)
-{
- set_capacity(md->disk, size);
-
- mutex_lock(&md->suspended_bdev->bd_inode->i_mutex);
- i_size_write(md->suspended_bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
- mutex_unlock(&md->suspended_bdev->bd_inode->i_mutex);
-}
-
static int __bind(struct mapped_device *md, struct dm_table *t)
{
struct request_queue *q = md->queue;
- sector_t size;
-
- size = dm_table_get_size(t);
-
- /*
- * Wipe any geometry if the size of the table changed.
- */
- if (size != get_capacity(md->disk))
- memset(&md->geometry, 0, sizeof(md->geometry));

- if (md->suspended_bdev)
- __set_size(md, size);
- if (size == 0)
+ if (!dm_table_get_size(t))
return 0;

dm_table_get(t);
@@ -1497,8 +1477,6 @@ int dm_resume(struct mapped_device *md)

dm_table_unplug_all(map);

- kobject_uevent(&md->disk->kobj, KOBJ_CHANGE);
-
r = 0;

out:
@@ -1508,6 +1486,43 @@ out:
return r;
}

+void dm_set_size(struct mapped_device *md)
+{
+ struct dm_table *map;
+ struct block_device *bdev;
+ sector_t size;
+
+ down(&md->suspend_lock);
+
+ map = dm_get_table(md);
+ if (!map)
+ goto out;
+
+ size = dm_table_get_size(map);
+
+ /*
+ * Wipe any geometry if the size of the table changed.
+ */
+ if (size != get_capacity(md->disk))
+ memset(&md->geometry, 0, sizeof(md->geometry));
+
+ set_capacity(md->disk, size);
+
+ bdev = bdlookup_disk(md->disk, 0);
+ if (bdev) {
+ mutex_lock(&bdev->bd_mutex);
+ i_size_write(bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
+ mutex_unlock(&bdev->bd_mutex);
+ bdput(bdev);
+ }
+
+ kobject_uevent(&md->disk->kobj, KOBJ_CHANGE);
+
+out:
+ dm_table_put(map);
+ up(&md->suspend_lock);
+}
+
/*-----------------------------------------------------------------
* Event notification.
*---------------------------------------------------------------*/
Index: linux-2.6.23.work/drivers/md/dm-ioctl.c
===================================================================
--- linux-2.6.23.work.orig/drivers/md/dm-ioctl.c
+++ linux-2.6.23.work/drivers/md/dm-ioctl.c
@@ -840,8 +840,10 @@ static int do_resume(struct dm_ioctl *pa
if (dm_suspended(md))
r = dm_resume(md);

- if (!r)
+ if (!r) {
+ dm_set_size(md);
r = __dev_status(md, param);
+ }

dm_put(md);
return r;
Index: linux-2.6.23.work/include/linux/device-mapper.h
===================================================================
--- linux-2.6.23.work.orig/include/linux/device-mapper.h
+++ linux-2.6.23.work/include/linux/device-mapper.h
@@ -198,6 +198,11 @@ int dm_noflush_suspending(struct dm_targ
int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);

+/*
+ * Update device size
+ */
+void dm_set_size(struct mapped_device *md);
+

/*-----------------------------------------------------------------
* Functions for manipulating device-mapper tables.