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path: root/drivers/block/drbd/drbd_main.c
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Diffstat (limited to 'drivers/block/drbd/drbd_main.c')
-rw-r--r--drivers/block/drbd/drbd_main.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 731a28e..76faeab 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2834,6 +2834,7 @@ void conn_md_sync(struct drbd_tconn *tconn)
rcu_read_unlock();
}
+/* aligned 4kByte */
struct meta_data_on_disk {
u64 la_size; /* last agreed size. */
u64 uuid[UI_SIZE]; /* UUIDs. */
@@ -2843,13 +2844,13 @@ struct meta_data_on_disk {
u32 magic;
u32 md_size_sect;
u32 al_offset; /* offset to this block */
- u32 al_nr_extents; /* important for restoring the AL */
+ u32 al_nr_extents; /* important for restoring the AL (userspace) */
/* `-- act_log->nr_elements <-- ldev->dc.al_extents */
u32 bm_offset; /* offset to the bitmap, from here */
u32 bm_bytes_per_bit; /* BM_BLOCK_SIZE */
u32 la_peer_max_bio_size; /* last peer max_bio_size */
- u32 reserved_u32[3];
+ u8 reserved_u8[4096 - (7*8 + 8*4)];
} __packed;
/**
@@ -2862,6 +2863,10 @@ void drbd_md_sync(struct drbd_conf *mdev)
sector_t sector;
int i;
+ /* Don't accidentally change the DRBD meta data layout. */
+ BUILD_BUG_ON(UI_SIZE != 4);
+ BUILD_BUG_ON(sizeof(struct meta_data_on_disk) != 4096);
+
del_timer(&mdev->md_sync_timer);
/* timer may be rearmed by drbd_md_mark_dirty() now. */
if (!test_and_clear_bit(MD_DIRTY, &mdev->flags))
@@ -2876,7 +2881,7 @@ void drbd_md_sync(struct drbd_conf *mdev)
if (!buffer)
goto out;
- memset(buffer, 0, 512);
+ memset(buffer, 0, sizeof(*buffer));
buffer->la_size = cpu_to_be64(drbd_get_capacity(mdev->this_bdev));
for (i = UI_CURRENT; i < UI_SIZE; i++)