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path: root/drivers/md/dm-snap.c
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Diffstat (limited to 'drivers/md/dm-snap.c')
-rw-r--r--drivers/md/dm-snap.c29
1 files changed, 18 insertions, 11 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 87727d84dbb..f3759dd7828 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -373,16 +373,11 @@ static inline ulong round_up(ulong n, ulong size)
static void read_snapshot_metadata(struct dm_snapshot *s)
{
- if (s->have_metadata)
- return;
-
if (s->store.read_metadata(&s->store)) {
down_write(&s->lock);
s->valid = 0;
up_write(&s->lock);
}
-
- s->have_metadata = 1;
}
/*
@@ -471,7 +466,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
s->chunk_shift = ffs(chunk_size) - 1;
s->valid = 1;
- s->have_metadata = 0;
+ s->active = 0;
s->last_percent = 0;
init_rwsem(&s->lock);
s->table = ti->table;
@@ -506,7 +501,11 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad5;
}
+ /* Metadata must only be loaded into one table at once */
+ read_snapshot_metadata(s);
+
/* Add snapshot to the list of snapshots for this origin */
+ /* Exceptions aren't triggered till snapshot_resume() is called */
if (register_snapshot(s)) {
r = -EINVAL;
ti->error = "Cannot register snapshot origin";
@@ -793,6 +792,9 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
if (!s->valid)
return -EIO;
+ if (unlikely(bio_barrier(bio)))
+ return -EOPNOTSUPP;
+
/*
* Write to snapshot - higher level takes care of RW/RO
* flags so we should only get this if we are
@@ -862,7 +864,9 @@ static void snapshot_resume(struct dm_target *ti)
{
struct dm_snapshot *s = (struct dm_snapshot *) ti->private;
- read_snapshot_metadata(s);
+ down_write(&s->lock);
+ s->active = 1;
+ up_write(&s->lock);
}
static int snapshot_status(struct dm_target *ti, status_type_t type,
@@ -932,8 +936,8 @@ static int __origin_write(struct list_head *snapshots, struct bio *bio)
/* Do all the snapshots on this origin */
list_for_each_entry (snap, snapshots, list) {
- /* Only deal with valid snapshots */
- if (!snap->valid)
+ /* Only deal with valid and active snapshots */
+ if (!snap->valid || !snap->active)
continue;
/* Nothing to do if writing beyond end of snapshot */
@@ -1057,6 +1061,9 @@ static int origin_map(struct dm_target *ti, struct bio *bio,
struct dm_dev *dev = (struct dm_dev *) ti->private;
bio->bi_bdev = dev->bdev;
+ if (unlikely(bio_barrier(bio)))
+ return -EOPNOTSUPP;
+
/* Only tell snapshots if this is a write */
return (bio_rw(bio) == WRITE) ? do_origin(dev, bio) : 1;
}
@@ -1104,7 +1111,7 @@ static int origin_status(struct dm_target *ti, status_type_t type, char *result,
static struct target_type origin_target = {
.name = "snapshot-origin",
- .version = {1, 0, 1},
+ .version = {1, 1, 0},
.module = THIS_MODULE,
.ctr = origin_ctr,
.dtr = origin_dtr,
@@ -1115,7 +1122,7 @@ static struct target_type origin_target = {
static struct target_type snapshot_target = {
.name = "snapshot",
- .version = {1, 0, 1},
+ .version = {1, 1, 0},
.module = THIS_MODULE,
.ctr = snapshot_ctr,
.dtr = snapshot_dtr,