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authorMikulas Patocka <mpatocka@redhat.com>2010-08-12 04:13:51 +0100
committerAlasdair G Kergon <agk@redhat.com>2010-08-12 04:13:51 +0100
commitc24110450650f17f7d3ba4fbe01f01ac5a115456 (patch)
tree8b5bff17f77c995099d93b2b4a32bc306962a0bf /drivers/md/dm-snap.c
parent1e5554c8428bc7209a83e2d07ca724be4d981ce3 (diff)
downloadlinaro-lsk-c24110450650f17f7d3ba4fbe01f01ac5a115456.tar.gz
dm snapshot: test chunk size against both origin and snapshot
Validate chunk size against both origin and snapshot sector size Don't allow chunk size smaller than either origin or snapshot logical sector size. Reading or writing data not aligned to sector size is not allowed and causes immediate errors. This requires us to open the origin before initialising the exception store and to export dm_snap_origin. Cc: stable@kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/dm-snap.c')
-rw-r--r--drivers/md/dm-snap.c36
1 files changed, 21 insertions, 15 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index a6ab98920cc..a1f2ab553b9 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -148,6 +148,12 @@ struct dm_snapshot {
#define RUNNING_MERGE 0
#define SHUTDOWN_MERGE 1
+struct dm_dev *dm_snap_origin(struct dm_snapshot *s)
+{
+ return s->origin;
+}
+EXPORT_SYMBOL(dm_snap_origin);
+
struct dm_dev *dm_snap_cow(struct dm_snapshot *s)
{
return s->cow;
@@ -1065,10 +1071,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
origin_mode = FMODE_WRITE;
}
- origin_path = argv[0];
- argv++;
- argc--;
-
s = kmalloc(sizeof(*s), GFP_KERNEL);
if (!s) {
ti->error = "Cannot allocate snapshot context private "
@@ -1077,6 +1079,16 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad;
}
+ origin_path = argv[0];
+ argv++;
+ argc--;
+
+ r = dm_get_device(ti, origin_path, origin_mode, &s->origin);
+ if (r) {
+ ti->error = "Cannot get origin device";
+ goto bad_origin;
+ }
+
cow_path = argv[0];
argv++;
argc--;
@@ -1097,12 +1109,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
argv += args_used;
argc -= args_used;
- r = dm_get_device(ti, origin_path, origin_mode, &s->origin);
- if (r) {
- ti->error = "Cannot get origin device";
- goto bad_origin;
- }
-
s->ti = ti;
s->valid = 1;
s->active = 0;
@@ -1212,15 +1218,15 @@ bad_kcopyd:
dm_exception_table_exit(&s->complete, exception_cache);
bad_hash_tables:
- dm_put_device(ti, s->origin);
-
-bad_origin:
dm_exception_store_destroy(s->store);
bad_store:
dm_put_device(ti, s->cow);
bad_cow:
+ dm_put_device(ti, s->origin);
+
+bad_origin:
kfree(s);
bad:
@@ -1314,12 +1320,12 @@ static void snapshot_dtr(struct dm_target *ti)
mempool_destroy(s->pending_pool);
- dm_put_device(ti, s->origin);
-
dm_exception_store_destroy(s->store);
dm_put_device(ti, s->cow);
+ dm_put_device(ti, s->origin);
+
kfree(s);
}