diff options
| author | Joe Thornber <ejt@redhat.com> | 2015-11-19 13:03:36 +0000 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2017-02-16 13:02:54 -0500 |
| commit | 3ba3ba1e8411532dc4a05b4e8932c9e358d70a44 (patch) | |
| tree | 163e9a4f68dd4ffddf87ba4b3f92dd67a39a56ef /drivers/md | |
| parent | 602548bdd5ac4ed7025d992e3ad61a628af4c500 (diff) | |
dm space map common: memcpy the disk root to ensure it's arch aligned
The metadata_space_map_root passed to sm_ll_open_metadata() may or may
not be arch aligned, use memcpy to ensure it is. This is not a fast
path so the extra memcpy doesn't hurt us.
Long-term it'd be better to use the kernel's alignment infrastructure to
remove the memcpy()s that are littered across persistent-data (btree,
array, space-maps, etc).
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/persistent-data/dm-space-map-common.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c index 4c28608a0c94..829b4ce057d8 100644 --- a/drivers/md/persistent-data/dm-space-map-common.c +++ b/drivers/md/persistent-data/dm-space-map-common.c @@ -626,13 +626,19 @@ int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm, void *root_le, size_t len) { int r; - struct disk_sm_root *smr = root_le; + struct disk_sm_root smr; if (len < sizeof(struct disk_sm_root)) { DMERR("sm_metadata root too small"); return -ENOMEM; } + /* + * We don't know the alignment of the root_le buffer, so need to + * copy into a new structure. + */ + memcpy(&smr, root_le, sizeof(smr)); + r = sm_ll_init(ll, tm); if (r < 0) return r; @@ -644,10 +650,10 @@ int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm, ll->max_entries = metadata_ll_max_entries; ll->commit = metadata_ll_commit; - ll->nr_blocks = le64_to_cpu(smr->nr_blocks); - ll->nr_allocated = le64_to_cpu(smr->nr_allocated); - ll->bitmap_root = le64_to_cpu(smr->bitmap_root); - ll->ref_count_root = le64_to_cpu(smr->ref_count_root); + ll->nr_blocks = le64_to_cpu(smr.nr_blocks); + ll->nr_allocated = le64_to_cpu(smr.nr_allocated); + ll->bitmap_root = le64_to_cpu(smr.bitmap_root); + ll->ref_count_root = le64_to_cpu(smr.ref_count_root); return ll->open_index(ll); } |