提交 042d2a9b 编写于 作者: A Alasdair G Kergon

dm: keep old table until after resume succeeded

When swapping a new table into place, retain the old table until
its replacement is in place.

An old check for an empty table is removed because this is enforced
in populate_table().

__unbind() becomes redundant when followed by __bind().
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
上级 a7940155
......@@ -855,7 +855,7 @@ static int do_resume(struct dm_ioctl *param)
unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
struct hash_cell *hc;
struct mapped_device *md;
struct dm_table *new_map;
struct dm_table *new_map, *old_map = NULL;
down_write(&_hash_lock);
......@@ -884,11 +884,11 @@ static int do_resume(struct dm_ioctl *param)
if (!dm_suspended(md))
dm_suspend(md, suspend_flags);
r = dm_swap_table(md, new_map);
if (r) {
old_map = dm_swap_table(md, new_map);
if (IS_ERR(old_map)) {
dm_table_destroy(new_map);
dm_put(md);
return r;
return PTR_ERR(old_map);
}
if (dm_table_get_mode(new_map) & FMODE_WRITE)
......@@ -900,6 +900,8 @@ static int do_resume(struct dm_ioctl *param)
if (dm_suspended(md))
r = dm_resume(md);
if (old_map)
dm_table_destroy(old_map);
if (!r) {
dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr);
......
......@@ -2033,9 +2033,13 @@ static void __set_size(struct mapped_device *md, sector_t size)
mutex_unlock(&md->bdev->bd_inode->i_mutex);
}
static int __bind(struct mapped_device *md, struct dm_table *t,
struct queue_limits *limits)
/*
* Returns old map, which caller must destroy.
*/
static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
struct queue_limits *limits)
{
struct dm_table *old_map;
struct request_queue *q = md->queue;
sector_t size;
unsigned long flags;
......@@ -2050,11 +2054,6 @@ static int __bind(struct mapped_device *md, struct dm_table *t,
__set_size(md, size);
if (!size) {
dm_table_destroy(t);
return 0;
}
dm_table_event_callback(t, event_callback, md);
/*
......@@ -2070,11 +2069,12 @@ static int __bind(struct mapped_device *md, struct dm_table *t,
__bind_mempools(md, t);
write_lock_irqsave(&md->map_lock, flags);
old_map = md->map;
md->map = t;
dm_table_set_restrictions(t, q, limits);
write_unlock_irqrestore(&md->map_lock, flags);
return 0;
return old_map;
}
/*
......@@ -2368,13 +2368,13 @@ static void dm_rq_barrier_work(struct work_struct *work)
}
/*
* Swap in a new table (destroying old one).
* Swap in a new table, returning the old one for the caller to destroy.
*/
int dm_swap_table(struct mapped_device *md, struct dm_table *table)
struct dm_table *dm_swap_table(struct mapped_device *md, struct dm_table *table)
{
struct dm_table *map;
struct dm_table *map = ERR_PTR(-EINVAL);
struct queue_limits limits;
int r = -EINVAL;
int r;
mutex_lock(&md->suspend_lock);
......@@ -2383,8 +2383,10 @@ int dm_swap_table(struct mapped_device *md, struct dm_table *table)
goto out;
r = dm_calculate_queue_limits(table, &limits);
if (r)
if (r) {
map = ERR_PTR(r);
goto out;
}
/* cannot change the device type, once a table is bound */
if (md->map &&
......@@ -2393,13 +2395,11 @@ int dm_swap_table(struct mapped_device *md, struct dm_table *table)
goto out;
}
map = __unbind(md);
r = __bind(md, table, &limits);
dm_table_destroy(map);
map = __bind(md, table, &limits);
out:
mutex_unlock(&md->suspend_lock);
return r;
return map;
}
/*
......
......@@ -295,8 +295,10 @@ void dm_table_event(struct dm_table *t);
/*
* The device must be suspended before calling this method.
* Returns the previous table, which the caller must destroy.
*/
int dm_swap_table(struct mapped_device *md, struct dm_table *t);
struct dm_table *dm_swap_table(struct mapped_device *md,
struct dm_table *t);
/*
* A wrapper around vmalloc.
......
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